[Endangered situation and conservation strategy of Tibetan medicine in Qinghai-Tibet Plateau].

PubMed

Zhao, Cai-Yun; Liu, Huan; Su, Jin-Song; Li, Xuan-Hao; Jia, Min-Ru; Zhang, Yi; Zhang, Jing

2016-12-01

With the rapid development of Tibetan medicine industry, the study on plateau medicinal plants' endangered status is not enough, measures to protect is weak and the plateau ecological environment' inherent vulnerability, resulted in the shortage of Tibetan medicinal resources and affect the sustainable development . According to the existing endangered information of Tibetan medicine resources, how to formulate feasible protection plan, is an urgent problem of the rational development and utilization of Tibetan medicine resources to be solved. To find out the endangered Tibetan medicines in Qinghai Tibet Plateau, the Grade division method of Chinese Rare and Endangered Plants was applied, the endangered species were sorted out, which divided into class one (threatened) eleven species, class two (rare) twenty-one species, and class three (fading) forty-two species,a total of seventy-four species.In addition to national protection list in "Chinese rare and endangered plants". It's proposed to increase the endangered Tibetan medicinal species. Finally, according to the endangered status of the resources,from the survey of endangered Tibetan medicinal species regularly, the germplasm repository establishment of endangered Tibetan medicine, in situ conservation, artificial cultivation research and renew the idea, reasonable development and utilization, a total of 5 aspects to discussed the protection strategy, to provide a scientific basis for the protection and sustainable utilization of Tibetan medicine resources in Qinghai-Tibet Plateau. Copyright© by the Chinese Pharmaceutical Association.

Wild Bird Migration across the Qinghai-Tibetan Plateau: A Transmission Route for Highly Pathogenic H5N1

PubMed Central

Prosser, Diann J.; Cui, Peng; Takekawa, John Y.; Tang, Mingjie; Hou, Yuansheng; Collins, Bridget M.; Yan, Baoping; Hill, Nichola J.; Li, Tianxian; Li, Yongdong; Lei, Fumin; Guo, Shan; Xing, Zhi; He, Yubang; Zhou, Yuanchun; Douglas, David C.; Perry, William M.; Newman, Scott H.

2011-01-01

Background Qinghai Lake in central China has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus H5N1. In 2005, an unprecedented epizootic at Qinghai Lake killed more than 6000 migratory birds including over 3000 bar-headed geese (Anser indicus). H5N1 subsequently spread to Europe and Africa, and in following years has re-emerged in wild birds along the Central Asia flyway several times. Methodology/Principal Findings To better understand the potential involvement of wild birds in the spread of H5N1, we studied the movements of bar-headed geese marked with GPS satellite transmitters at Qinghai Lake in relation to virus outbreaks and disease risk factors. We discovered a previously undocumented migratory pathway between Qinghai Lake and the Lhasa Valley of Tibet where 93% of the 29 marked geese overwintered. From 2003–2009, sixteen outbreaks in poultry or wild birds were confirmed on the Qinghai-Tibet Plateau, and the majority were located within the migratory pathway of the geese. Spatial and temporal concordance between goose movements and three potential H5N1 virus sources (poultry farms, a captive bar-headed goose facility, and H5N1 outbreak locations) indicated ample opportunities existed for virus spillover and infection of migratory geese on the wintering grounds. Their potential as a vector of H5N1 was supported by rapid migration movements of some geese and genetic relatedness of H5N1 virus isolated from geese in Tibet and Qinghai Lake. Conclusions/Significance This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold. PMID:21408010

Wild bird migration across the Qinghai-Tibetan plateau: a transmission route for highly pathogenic H5N1.

PubMed

Prosser, Diann J; Cui, Peng; Takekawa, John Y; Tang, Mingjie; Hou, Yuansheng; Collins, Bridget M; Yan, Baoping; Hill, Nichola J; Li, Tianxian; Li, Yongdong; Lei, Fumin; Guo, Shan; Xing, Zhi; He, Yubang; Zhou, Yuanchun; Douglas, David C; Perry, William M; Newman, Scott H

2011-03-09

Qinghai Lake in central China has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus H5N1. In 2005, an unprecedented epizootic at Qinghai Lake killed more than 6000 migratory birds including over 3000 bar-headed geese (Anser indicus). H5N1 subsequently spread to Europe and Africa, and in following years has re-emerged in wild birds along the Central Asia flyway several times. To better understand the potential involvement of wild birds in the spread of H5N1, we studied the movements of bar-headed geese marked with GPS satellite transmitters at Qinghai Lake in relation to virus outbreaks and disease risk factors. We discovered a previously undocumented migratory pathway between Qinghai Lake and the Lhasa Valley of Tibet where 93% of the 29 marked geese overwintered. From 2003-2009, sixteen outbreaks in poultry or wild birds were confirmed on the Qinghai-Tibet Plateau, and the majority were located within the migratory pathway of the geese. Spatial and temporal concordance between goose movements and three potential H5N1 virus sources (poultry farms, a captive bar-headed goose facility, and H5N1 outbreak locations) indicated ample opportunities existed for virus spillover and infection of migratory geese on the wintering grounds. Their potential as a vector of H5N1 was supported by rapid migration movements of some geese and genetic relatedness of H5N1 virus isolated from geese in Tibet and Qinghai Lake. This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold.

Molecular biogeography of tribe Thermopsideae (Leguminosae): A Madrean-Tethyan disjunction pattern with an African origin of core genistoides

Treesearch

Ming-Li Zhang; Jian-Feng Huang; Stewart C. Sanderson; Ping Yan; Yu-H Wu; Bo-Rong Pan

2015-01-01

Thermopsideae has 45 species and exhibits a series of interesting biogeographical distribution patterns, such as Madrean-Tethyan disjunction and EastAsia-North America disjunction,with a center of endemism in the Qinghai-Xizang Plateau (QTP) and Central Asia. Phylogenetic analysis in this paper employed maximum likelihood using ITS, rps16, psbA-trnH, and trnL-F...

Evaluation of the Township Proper Carrying Capacity over Qinghai-Tibet plateau by CASA model

NASA Astrophysics Data System (ADS)

Wu, Chengyong; Cao, Guangchao; Xue, Huaju; Jiang, Gang; Wang, Qi; Yuan, Jie; Chen, Kelong

2018-01-01

The existing study of proper carrying capacity (PCC) has mostly focused on province or county administrative units, which can only macroscopically master the quantitative characteristics of PCC, but could not effectively take some animal husbandry management measures that are pertinent and operational. At town-scale, this paper used CASA model to estimate the PCC in Mongolian Autonomous County of Henan, Qinghai province, China,with serious grassland degeneration that mainly caused by overgrazing. The results showed that the PCC throughout the County was 950,417 sheep unit. For the township, the PCC of Saierlong and Duosong were the largest (247,100 sheep unit) and the smallest (82,016 sheep unit) respectively. This study will provide reference data for developing sustainable development of town-scale pasture policies and also will help to evaluate the health status of the alpine grassland ecosystem on Qinghai-Tibet plateau.

Annual ecosystem respiration variability of alpine peatland on the eastern Qinghai-Tibet Plateau and its controlling factors.

PubMed

Peng, Haijun; Hong, Bing; Hong, Yetang; Zhu, Yongxuan; Cai, Chen; Yuan, Lingui; Wang, Yu

2015-09-01

Peatlands are widely developed in the eastern Qinghai-Tibet Plateau, but little is known about carbon budgets for these alpine peatland ecosystems. In this study, we used an automatic chamber system to measure ecosystem respiration in the Hongyuan peatland, which is located in the eastern Qinghai-Tibet Plateau. Annual ecosystem respiration measurements showed a typical seasonal pattern, with the peak appearing in June. The highest respiration was 10.43 μmol CO2/m(2)/s, and the lowest was 0.20 μmol CO2/m(2)/s. The annual average ecosystem respiration was 2.06 μmol CO2/m(2)/s. The total annual respiration was 599.98 g C/m(2), and respiration during the growing season (from May to September) accounted for 78 % of the annual sum. Nonlinear regression revealed that ecosystem respiration has a significant exponential correlation with soil temperature at 10-cm depth (R (2) = 0.98). The Q 10 value was 3.90, which is far higher than the average Q 10 value of terrestrial ecosystems. Ecosystem respiration had an apparent diurnal variation pattern in growing season, with peaks and valleys appearing at approximately 14:00 and 10:00, respectively, which could be explained by soil temperature and soil water content variation at 10-cm depth.

Characterization of the prokaryotic diversity through a stratigraphic permafrost core profile from the Qinghai-Tibet Plateau.

PubMed

Hu, Weigang; Zhang, Qi; Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; An, Lizhe; Feng, Huyuan

2016-05-01

Permafrost on the Qinghai-Tibet Plateau is one of the most sensitive regions to climate warming, thus characterizing its microbial diversity and community composition may be important for understanding their potential responses to climate changes. Here, we investigated the prokaryotic diversity in a 10-m-long permafrost core from the Qinghai-Tibet Plateau by restriction fragment length polymorphism analysis targeting the 16S rRNA gene. We detected 191 and 17 bacterial and archaeal phylotypes representing 14 and 2 distinct phyla, respectively. Proteobacteria was the dominant bacterial phylum, while archaeal communities were characterized by a preponderance of Thaumarchaeota. Some of prokaryotic phylotypes were closely related to characterized species involved in carbon and nitrogen cycles, including nitrogen fixation, methane oxidation and nitrification. However, the majority of the phylotypes were only distantly related to known taxa at order or species level, suggesting the potential of novel diversity. Additionally, both bacterial α diversity and community composition changed significantly with sampling depth, where these communities mainly distributed according to core horizons. Arthrobacter-related phylotypes presented at high relative abundance in two active layer soils, while the deeper permafrost soils were dominated by Psychrobacter-related clones. Changes in bacterial community composition were correlated with most measured soil variables, such as carbon and nitrogen contents, pH, and conductivity.

Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau.

PubMed

Qi, Juan; Nie, Zhongnan; Jiao, Ting; Zhang, Degang

2015-01-01

Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau

PubMed Central

Qi, Juan; Nie, Zhongnan; Jiao, Ting; Zhang, Degang

2015-01-01

Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries. PMID:26513363

Contribution to knowledge of the genus Chydaeus in Xizang Autonomous Region [Tibet] and Yunnan Province, China (Coleoptera, Carabidae, Harpalini)

PubMed Central

Kataev, Boris M.; Liang, Hongbin; Kavanaugh, David H.

2012-01-01

Abstract Five new species of the genus Chydaeus Chaudoir, 1854 are described from China: Chydaeus fugongensis sp. n. (Shibali, Fugong County, Yunnan Province), Chydaeus gutangensis sp. n. (Gutang, Medog County, Xizang Autonomous Region [Tibet]), Chydaeus hanmiensis sp. n. (Hanmi, Medog County, Xizang Autonomous Region [Tibet]), Chydaeus asetosus sp. n. (NE of Fugong, Yunnan Province), and Chydaeus baoshanensis sp. n. (N of Baoshan, Yunnan Province). Taxonomic and faunistic notes on eleven other species occurring in Xizang and Yunnan are also provided. Chydaeus shunichii Ito, 2006 is re-described, based on specimens from Lushui County, Yunnan. Chydaeus kumei Ito, 1992 is treated as a subspecies of Chydaeus andrewesi Schauberger, 1932 [NEW STATUS]. The taxonomic status of Chydaeus guangxiensis Ito, 2006 is discussed. The following taxa are recorded from China for the first time: Chydaeus obtusicollis Schauberger, 1932 (Xizang and Yunnan), Chydaeus malaisei Kataev & Schmidt, 2006 (Yunnan), Chydaeus semenowi (Tschitschérine, 1899) (Xizang and Yunnan), Chydaeus andrewesi andrewesi Schauberger, 1932 (Xizang and Yunnan), Chydaeus andrewesi kumei Ito (Yunnan), Chydaeus bedeli interjectus Kataev & Schmidt, 2002 (Xizang), and Chydaeus bedeli vietnamensis Kataev & Schmidt, 2002 (Yunnan). PMID:22423195

[Carbon balance of household production system in the transition zone from the Loess Plateau to the Qinghai-Tibet Plateau, China].

PubMed

Wu, Chao Chao; Gao, Xiao Ye; Hou, Fu Jiang

2017-10-01

The transition zone from the Loess Plateau to the Qinghai-Tibet Plateau is one of the regions with most dramatic changes in agricultural production mode and most sensitive response to the carbon balance effect. This paper analyzed the carbon balance of the agriculture system along the altitude gradient in Tongwei, Weiyuan and Xiahe counties. The results showed that with the increase of altitude, the carbon emission, carbon fixation and carbon sink capacity of crops per unit area decreased accordingly, while the average carbon emission, carbon fixation and carbon source capacity of each household in livestock system increased. The integrated crop-livestock production system changed from carbon sink to carbon source. The average carbon emission of each household rose with altitude, but the carbon fixation was the opposite. The change of percentage ofhousehold in the transition zone from the Loess Plateau to the Qinghai-Tibet Plateau with carbon balance could be fitted with Logistic equation. In the crop system of Tongwei, Weiyuan and Xiahe with the altitude increase, carbon emission at the inflection point where the household percentage accounted for 50.0% was 1491, 857 and 376 kg CE·household -1 , and carbon fixation was 6187, 3872 and 778 kg CE·household -1 , respectively. For the livestock system, carbon emission was 2218, 3725 and 49511 kg CE·household -1 , and carbon fixation was 138, 230 and 2706 kg CE·household -1 , respectively. For the integrated crop-livestock system, carbon emission was 3615, 4583 and 49918 kg CE·household -1 , and carbon fixation was 6289, 4113 and 3819 kg CE·household -1 , respectively, which could be the key point for the regulation of regional carbon balance.

Wild bird migration across the Qinghai-Tibetan Plateau: A transmission route for highly pathogenic H5N1

USGS Publications Warehouse

Prosser, Diann J.; Cui, Peng; Takekawa, John Y.; Tang, Mingjie; Hou, Yuansheng; Collins, Bridget M.; Yan, Baoping; Hill, Nichola J.; Li, Tianxian; Li, Yongdong; Lei, Fumin; Guo, Shan; Xing, Zhi; He, Yubang; Zhou, Yuanchun; Douglas, David C.; Perry, William M.; Newman, Scott H.

2011-01-01

This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold.

Effects of the Qinghai-Tibet Railway on the Landscape Genetics of the Endangered Przewalski's Gazelle (Procapra przewalskii).

PubMed

Yu, He; Song, Shiya; Liu, Jiazi; Li, Sheng; Zhang, Lu; Wang, Dajun; Luo, Shu-Jin

2017-12-21

The Przewalski's gazelle (Procapra przewalskii) is one of the most endangered ungulates in the world, with fewer than 2,000 individuals surviving in nine habitat fragments on the Qinghai-Tibet Plateau and isolated by human settlements and infrastructure. In particular, the Qinghai-Tibet railway, which crosses the largest part of the gazelle's distribution, remains a major concern because of its potential to intensify landscape genetic differentiation. Here, using mtDNA sequencing and microsatellite genotyping to analyze 275 Przewalski's gazelle samples collected throughout the range, we observed low level of genetic diversity (mtDNA π = 0.0033) and strong phylogeographic structure. Overall, the nine patches of gazelles can be further clustered into five populations, with a strong division between the eastern vs. western side of Qinghai Lake. Our study provides the first evidence of the genetic divergence between the Haergai North and Haergai South gazelle populations, corresponding to the recent construction of a wired enclosure along the Qinghai-Tibet railway less than ten years ago, an equivalent of five generations. Well-designed wildlife corridors across the railway along with long-term monitoring of the anthropogenic effects are therefore recommended to alleviate further habitat fragmentation and loss of genetic diversity in Przewalski's gazelle.

Impacts of Global Change on Water Resources in Dryland East Asia

Treesearch

Ge Sun; Xiaoming Feng; Jingfeng Xiao; Alex Shiklomanov; Shengping Wang; Zhiqiang Zhang; Nan Lu; Shuai Wang; Liding Chen; Bojie Fu; Yaning Chen; Jiquan Chen

2013-01-01

The vast Dryland East Asia (DEA) area consists of several large geographic regions including the Qinghai-Tibet Plateau, Loess Plateau, and Mongolia Plateau. T he region is of great importance to the functioning of the earth system under a changing climate. In the past three decades, due to the unprecedented land use/land cover change, urbanization, industrialization...

[Soil N/P ratio distribution characteristics of alpine grassland ecosystem in Qinghai-Tibet Plateau].

PubMed

Wang, Jian-Lin; Zhong, Zhi-Ming; Wang, Zhong-Hong; Chen, Bao-Xiong; Zhang, Xian-Zhou; Shen, Zhen-Xi; Hu, Xing-Xiang; Dacizhuoga

2013-12-01

The distribution characteristics of soil N/P ratio in alpine grassland ecosystem of Qinghai-Tibet Plateau were surveyed by field investigation and laboratory analysis. Horizontally, soil N/ P ratio was generally higher in west and lower in east in a manner of staggered patch distribution, with higher N/P ratios mainly centralized in the hinterland of northern part of Tibet Plateau and in the lake basin area of the northern foot of Himalayas. Significant differences in soil N/P ratio were observed among grassland types and natural transects. Vertically, the distribution of N/P ratio along the soil profile from aboveground to underground among different grass types could be categorized into five patterns, including low-high-low-high, low-high-low, low-high, high-low-high-low, and high-low-high. The N/P ratio showed a significant positive correlation with soil bulk density at 0-20 cm depth, soil water content at 20-30 cm depth, contents of soil available K and total nitrogen, respectively. However, it showed significant negative correlation with soil bulk density at 20-30 cm depth, contents of soil available P and total P, respectively.

Reconstruction of a Three Hourly 1-km Land Surface Air Temperature Dataset in the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Zhou, J.; Ding, L.

2017-12-01

Land surface air temperature (SAT) is an important parameter in the modeling of radiation balance and energy budget of the earth surface. Generally, SAT is measured at ground meteorological stations; then SAT mapping is possible though a spatial interpolation process. The interpolated SAT map relies on the spatial distribution of ground stations, the terrain, and many other factors; thus, it has great uncertainties in regions with complicated terrain. Instead, SAT map can also be obtained through physical modeling of interactions between the land surface and the atmosphere. Such dataset generally has coarse spatial resolution (e.g. coarser than 0.1°) and cannot satisfy the applications at fine scales, e.g. 1 km. This presentation reports the reconstruction of a three hourly 1-km SAT dataset from 2001 to 2015 over the Qinghai-Tibet Plateau. The terrain in the Qinghai-Tibet Plateau, especially in the eastern part, is extremely complicated. Two SAT datasets with good qualities are used in this study. The first one is from the 3h China Meteorological Forcing Dataset with a 0.1° resolution released by the Institute of Tibetan Plateau Research, Chinese Academy of Sciences (Yang et al., 2010); the second one is from the ERA-Interim product with the same temporal resolution and a 0.125° resolution. A statistical approach is developed to downscale the spatial resolution of the derived SAT to 1-km. The elevation and the normalized difference vegetation index (NDVI) are selected as two scaling factors in the downscaling approach. Results demonstrate there is significantly negative correlation between the SAT and elevation in all seasons; there is also significantly negative correlation between the SAT and NDVI in the vegetation growth seasons, while the correlation decreases in the other seasons. Therefore, a temporally dynamic downscaling approach is feasible to enhance the spatial resolution of the SAT. Compared with the SAT at the 0.1° or 0.125°, the reconstructed 1-km SAT can provide much more spatial details in areas with complicated terrain. Additionally, the 1-km SAT agrees well with the ground measured air temperatures as well as the SAT before downscaling. The reconstructed SAT will be beneficial for the modeling of surface radiation balance and energy budget over the Qinghai-Tibet Plateau.

Molecular phylogeny and biogeography of the Qinghai-Tibet Plateau endemic Nannoglottis (Asteraceae).

PubMed

Liu, Jian-Quan; Gao, Tian-Gang; Chen, Zhi-Duan; Lu, An-Ming

2002-06-01

All taxa endemic to the Qinghai-Tibet Plateau are hypothesized to have originated in situ or from immediately adjacent areas because of the relatively recent formation of the plateau since the Pliocene, followed by the large-scaled biota extinction and recession caused by the Quaternary ice sheet. However, identification of specific progenitors remains difficult for some endemics, especially some endemic genera. Nannoglottis, with about eight species endemic to this region, is one such genus. Past taxonomic treatments have suggested its relationships with four different tribes of Asteraceae. We intend to identify the closest relatives of Nannoglottis by evaluating the level of monophyly, tribal delimitation, and systematic position of the genus by using molecular data from ndhF gene, trnL-F, and ITS region sequences. We find that all sampled species of Nannoglottis are a well-defined monophyly. This supports all recent taxonomic treatments of Nannoglottis, in which all sampled species were placed in one broadly re-circumscribed genus. Nannoglottis is most closely related to the Astereae, but stands as an isolated genus as the first diverging lineage of the tribe, without close relatives. A tentative relationship was suggested for Nannoglottis and the next lineage of the tribe was based on the ITS topology, the "basal group," which consists of seven genera from the Southern Hemisphere. Such a relationship is supported by some commonly shared plesiomorphic morphological characters. Despite the very early divergence of Nannoglottis in the Astereae, the tribe must be regarded to have its origin in Southern Hemisphere rather than in Asia, because based on all morphological, molecular, biogeographical, and fossil data, the Asteraceae and its major lineages (tribes) are supposed to have originated in the former area. Long-distance dispersal using Southeast Asia as a steppingstone from Southern Hemisphere to the Qinghai-Tibet Plateau is the most likely explanation for this unusual biogeographic link of Nannoglottis. The 23-32-million-year divergence time between Nannoglottis and the other Astereae estimated by DNA sequences predated the formation of the plateau. This estimation is further favored by the fossil record of the Asteraceae and the possible time of origin of the Astereae. Nannoglottis seems to have reached the Qinghai-Tibet area in the Oligocene-Eocene and then re-diversified with the uplift of the plateau. The molecular infragenetic phylogeny of the genus identifies two distinct clades, which reject the earlier infrageneric classification based on the arrangement of the involucral bracts and the length of the ligules, but agree well with the habits and ecological preferences of its current species. The "alpine shrub" vs. "coniferous forest" divergence within Nannoglottis was estimated at about 3.4 million years ago when the plateau began its first large-scale uplifting and the coniferous vegetation began to appear. Most of the current species at the "coniferous forest" clade of the genus are estimated to have originated from 1.02 to 1.94 million years ago, when the second and third uprisings of the plateau occurred, the climate oscillated and the habitats were strongly changed. The assumed evolution, speciation diversity, and radiation of Nannoglottis based on molecular phylogeny and divergence times agree well with the known geological and paleobotanical histories of the Qinghai-Tibet Plateau. (c) 2002 Elsevier Science (USA).

Spatiotemporal dynamics of grassland aboveground biomass on the Qinghai-Tibet Plateau based on validated MODIS NDVI.

PubMed

Liu, Shiliang; Cheng, Fangyan; Dong, Shikui; Zhao, Haidi; Hou, Xiaoyun; Wu, Xue

2017-06-23

Spatiotemporal dynamics of aboveground biomass (AGB) is a fundamental problem for grassland environmental management on the Qinghai-Tibet Plateau (QTP). Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data can feasibly be used to estimate AGB at large scales, and their precise validation is necessary to utilize them effectively. In our study, the clip-harvest method was used at 64 plots in QTP grasslands to obtain actual AGB values, and a handheld hyperspectral spectrometer was used to calculate field-measured NDVI to validate MODIS NDVI. Based on the models between NDVI and AGB, AGB dynamics trends during 2000-2012 were analyzed. The results showed that the AGB in QTP grasslands increased during the study period, with 70% of the grasslands undergoing increases mainly in the Qinghai Province. Also, the meadow showed a larger increasing trend than steppe. Future AGB dynamic trends were also investigated using a combined analysis of the slope values and the Hurst exponent. The results showed high sustainability of AGB dynamics trends after the study period. Predictions indicate 60% of the steppe and meadow grasslands would continue to increase in AGB, while 25% of the grasslands would remain in degradation, with most of them distributing in Tibet.

Complete genome sequence of Bacillus velezensis LM2303, a biocontrol strain isolated from the dung of wild yak inhabited Qinghai-Tibet plateau.

PubMed

Chen, Liang

2017-06-10

Bacillus velezensis LM2303 is a biocontrol strain with a broad inhibitory spectrum against plant pathogens, isolated from the dung of wild yak inhabited Qinghai-Tibet plateau, China. Here we present its complete genome sequence, which consists of a single, circular chromosome of 3,989,393bp with a 46.68% G+C content. Genome analysis revealed genes encoding specialized functions for the biosynthesis of antifungal metabolites and antibacterial metabolites, the promotion of plant growth, the alleviation of oxidative stress and nutrient utilization. And the biosynthesis of antimicrobial metabolites in strain LM2303 was confirmed by biochemical analysis, while its plant growth promoting traits were confirmed by inoculation tests. Our results will establish a better foundation for further studies and biocontrol application of B. velezensis LM2303. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationships between Heavy Metal Concentrations in Roadside Topsoil and Distance to Road Edge Based on Field Observations in the Qinghai-Tibet Plateau, China

PubMed Central

Yan, Xuedong; Gao, Dan; Zhang, Fan; Zeng, Chen; Xiang, Wang; Zhang, Man

2013-01-01

This study investigated the spatial distribution of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), chromium (Cr), cobalt (Co), nickel (Ni) and arsenic (As) in roadside topsoil in the Qinghai-Tibet Plateau and evaluated the potential environmental risks of these roadside heavy metals due to traffic emissions. A total of 120 topsoil samples were collected along five road segments in the Qinghai-Tibet Plateau. The nonlinear regression method was used to formulize the relationship between the metal concentrations in roadside soils and roadside distance. The Hakanson potential ecological risk index method was applied to assess the degrees of heavy metal contaminations. The regression results showed that both of the heavy metals’ concentrations and their ecological risk indices decreased exponentially with the increase of roadside distance. The large R square values of the regression models indicate that the exponential regression method can suitably describe the relationship between heavy metal accumulation and roadside distance. For the entire study region, there was a moderate level of potential ecological risk within a 10 m roadside distance. However, Cd was the only prominent heavy metal which posed potential hazard to the local soil ecosystem. Overall, the rank of risk contribution to the local environments among the eight heavy metals was Cd > As > Ni > Pb > Cu > Co > Zn > Cr. Considering that Cd is a more hazardous heavy metal than other elements for public health, the local government should pay special attention to this traffic-related environmental issue. PMID:23439515

Pollution, ecological-health risks, and sources of heavy metals in soil of the northeastern Qinghai-Tibet Plateau.

PubMed

Wu, Jun; Lu, Jian; Li, Leiming; Min, Xiuyun; Luo, Yongming

2018-06-01

The Qinghai-Tibet Plateau, especially the northeastern region, is not a pure land any more due to recently increasing anthropogenic activities. This study collected soil samples from 70 sites of the northeastern Qinghai-Tibet Plateau to evaluate pollution, ecological-health risks, and possible pollution sources of heavy metals. The concentrations of heavy metals in soil were relatively high. Values of geo-accumulation index exhibited that Hg pollution was the most serious meanwhile Hg possessed the strongest enrichment feature based on enrichment factor values. The modified degrees of contamination showed that about 54.3% and 17.1% of sampling sites were at moderate and high contamination degree while pollution load indexes illustrated that 72.9% and 27.1% of sampling sites possessed moderate and high contamination level, respectively. Ecological risk indexes of heavy metals in soil ranged from 234.6 to 3759.0, suggesting that most of sites were under considerable/very high risks. Cancer risks for adults and children were determined as high and high-very high levels while non-cancer risks for children were high although those for adults were low. Industrial source contributed to the main fraction of ecological and health risks. Summarily speaking, heavy metals in soil of the study area has caused significantly serious pollution and exerted high potential ecological and health risks, especially for children who are more susceptible to hurt from pollutants. Therefore, more efficient and strict pollution control and management in study area should be put out as soon as possible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hypoxia adaptations in the grey wolf (Canis lupus chanco) from Qinghai-Tibet Plateau.

PubMed

Zhang, Wenping; Fan, Zhenxin; Han, Eunjung; Hou, Rong; Zhang, Liang; Galaverni, Marco; Huang, Jie; Liu, Hong; Silva, Pedro; Li, Peng; Pollinger, John P; Du, Lianming; Zhang, XiuyYue; Yue, Bisong; Wayne, Robert K; Zhang, Zhihe

2014-07-01

The Tibetan grey wolf (Canis lupus chanco) occupies habitats on the Qinghai-Tibet Plateau, a high altitude (>3000 m) environment where low oxygen tension exerts unique selection pressure on individuals to adapt to hypoxic conditions. To identify genes involved in hypoxia adaptation, we generated complete genome sequences of nine Chinese wolves from high and low altitude populations at an average coverage of 25× coverage. We found that, beginning about 55,000 years ago, the highland Tibetan grey wolf suffered a more substantial population decline than lowland wolves. Positively selected hypoxia-related genes in highland wolves are enriched in the HIF signaling pathway (P = 1.57E-6), ATP binding (P = 5.62E-5), and response to an oxygen-containing compound (P≤5.30E-4). Of these positively selected hypoxia-related genes, three genes (EPAS1, ANGPT1, and RYR2) had at least one specific fixed non-synonymous SNP in highland wolves based on the nine genome data. Our re-sequencing studies on a large panel of individuals showed a frequency difference greater than 58% between highland and lowland wolves for these specific fixed non-synonymous SNPs and a high degree of LD surrounding the three genes, which imply strong selection. Past studies have shown that EPAS1 and ANGPT1 are important in the response to hypoxic stress, and RYR2 is involved in heart function. These three genes also exhibited significant signals of natural selection in high altitude human populations, which suggest similar evolutionary constraints on natural selection in wolves and humans of the Qinghai-Tibet Plateau.

Hydro-meteorological processes on the Qinghai - Tibet Plateau observed from space

NASA Astrophysics Data System (ADS)

Menenti, Massimo; Colin, Jerome; Jia, Li; D'Urso, Guido; Foken, Thomas; Immerzeel, Walter; Jha, Ramakar; Liu, Qinhuo; Liu, Changming; Ma, Yaoming; Sobrino, Jose Antonio; Yan, Guangjian; Pelgrum, Henk; Porcu, Federico; Wang, Jian; Wang, Jiemin; Shen, Xueshun; Su, Zhongbo; Ueno, Kenichi

2014-05-01

The Qinghai - Tibet Plateau is characterized by a significant intra-annual variability and spatial heterogeneity of surface conditions. Snow and vegetation cover, albedo, surface temperature and wetness change very significantly during the year and from place to place. The influence of temporal changes on convective events and the onset of the monsoon has been documented by ground based measurements of land - atmosphere exchanges of heat and water. The state of the land surface over the entire Plateau can be determined by space observation of surface albedo, temperature, snow and vegetation cover and soil moisture. Fully integrated use of satellite and ground observations is necessary to support water resources management in SE Asia and to clarify the roles of the interactions between the land surface and the atmosphere over the Tibetan Plateau in the Asian monsoon system. New or significantly improved algorithms have been developed and evaluated against ground measurements. Variables retrieved include land surface properties, rain rate, aerosol optical depth, water vapour, snow cover and water equivalent, soil moisture and lake level. The three years time series of gap-free daily and hourly evaporation derived from geostationary data collected by the FY-2D satellite was a major achievement. The hydrologic modeling system has been implemented and applied to the Qinghai Tibet Plateau and the headwaters of the major rivers in South and East Asia. Case studies on response of atmospheric circulation and specifically of convective activity to land surface conditions have been completed and the controlling land surface conditions and processes have been documented. Two new drought indicators have been developed: Normalized Temperature Anomaly Index (NTAI) and Normalized Vegetation Anomaly Index (NVAI). Case study in China and India showed that these indicators capture effectively drought severity and evolution. A new method has been developed for monitoring and early warning of flooded areas at the regional scale.

Arbuscular mycorrhizal fungal community composition affected by original elevation rather than translocation along an altitudinal gradient on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Yang, Wei; Zheng, Yong; Gao, Cheng; Duan, Ji-Chuang; Wang, Shi-Ping; Guo, Liang-Dong

2016-11-01

Elucidating arbuscular mycorrhizal (AM) fungal responses to elevation changes is critical to improve understanding of microbial function in ecosystems under global asymmetrical climate change scenarios. Here we examined AM fungal community in a two-year reciprocal translocation of vegetation-intact soil blocks along an altitudinal gradient (3,200 m to 3,800 m) in an alpine meadow on the Qinghai-Tibet Plateau. AM fungal spore density was significantly higher at lower elevation than at higher elevation regardless of translocation, except that this parameter was significantly increased by upward translocation from original 3,200 m to 3,400 m and 3,600 m. Seventy-three operational taxonomic units (OTUs) of AM fungi were recovered using 454-pyrosequencing of 18S rDNA sequences at a 97% sequence similarity. Original elevation, downward translocation and upward translocation did not significantly affect AM fungal OTU richness. However, with increasing altitude the OTU richness of Acaulosporaceae and Ambisporaceae increased, but the OTU richness of Gigasporaceae and Glomeraceae decreased generally. The AM fungal community composition was significantly structured by original elevation but not by downward translocation and upward translocation. Our findings highlight that compared with the short-term reciprocal translocation, original elevation is a stronger determinant in shaping AM fungal community in the Qinghai-Tibet alpine meadow.

Arbuscular mycorrhizal fungal community composition affected by original elevation rather than translocation along an altitudinal gradient on the Qinghai-Tibet Plateau.

PubMed

Yang, Wei; Zheng, Yong; Gao, Cheng; Duan, Ji-Chuang; Wang, Shi-Ping; Guo, Liang-Dong

2016-11-09

Elucidating arbuscular mycorrhizal (AM) fungal responses to elevation changes is critical to improve understanding of microbial function in ecosystems under global asymmetrical climate change scenarios. Here we examined AM fungal community in a two-year reciprocal translocation of vegetation-intact soil blocks along an altitudinal gradient (3,200 m to 3,800 m) in an alpine meadow on the Qinghai-Tibet Plateau. AM fungal spore density was significantly higher at lower elevation than at higher elevation regardless of translocation, except that this parameter was significantly increased by upward translocation from original 3,200 m to 3,400 m and 3,600 m. Seventy-three operational taxonomic units (OTUs) of AM fungi were recovered using 454-pyrosequencing of 18S rDNA sequences at a 97% sequence similarity. Original elevation, downward translocation and upward translocation did not significantly affect AM fungal OTU richness. However, with increasing altitude the OTU richness of Acaulosporaceae and Ambisporaceae increased, but the OTU richness of Gigasporaceae and Glomeraceae decreased generally. The AM fungal community composition was significantly structured by original elevation but not by downward translocation and upward translocation. Our findings highlight that compared with the short-term reciprocal translocation, original elevation is a stronger determinant in shaping AM fungal community in the Qinghai-Tibet alpine meadow.

Arbuscular mycorrhizal fungal community composition affected by original elevation rather than translocation along an altitudinal gradient on the Qinghai-Tibet Plateau

PubMed Central

Yang, Wei; Zheng, Yong; Gao, Cheng; Duan, Ji-Chuang; Wang, Shi-Ping; Guo, Liang-Dong

2016-01-01

Elucidating arbuscular mycorrhizal (AM) fungal responses to elevation changes is critical to improve understanding of microbial function in ecosystems under global asymmetrical climate change scenarios. Here we examined AM fungal community in a two-year reciprocal translocation of vegetation-intact soil blocks along an altitudinal gradient (3,200 m to 3,800 m) in an alpine meadow on the Qinghai-Tibet Plateau. AM fungal spore density was significantly higher at lower elevation than at higher elevation regardless of translocation, except that this parameter was significantly increased by upward translocation from original 3,200 m to 3,400 m and 3,600 m. Seventy-three operational taxonomic units (OTUs) of AM fungi were recovered using 454-pyrosequencing of 18S rDNA sequences at a 97% sequence similarity. Original elevation, downward translocation and upward translocation did not significantly affect AM fungal OTU richness. However, with increasing altitude the OTU richness of Acaulosporaceae and Ambisporaceae increased, but the OTU richness of Gigasporaceae and Glomeraceae decreased generally. The AM fungal community composition was significantly structured by original elevation but not by downward translocation and upward translocation. Our findings highlight that compared with the short-term reciprocal translocation, original elevation is a stronger determinant in shaping AM fungal community in the Qinghai-Tibet alpine meadow. PMID:27827400

Genetic diversity and distribution patterns of host insects of Caterpillar Fungus Ophiocordyceps sinensis in the Qinghai-Tibet Plateau.

PubMed

Quan, Qing-Mei; Chen, Ling-Ling; Wang, Xi; Li, Shan; Yang, Xiao-Ling; Zhu, Yun-Guo; Wang, Mu; Cheng, Zhou

2014-01-01

The caterpillar fungus Ophiocordyceps sinensis is one of the most valuable medicinal fungi in the world, and it requires host insects in family Hepialidae (Lepidoptera) to complete its life cycle. However, the genetic diversity and phylogeographic structures of the host insects remain to be explored. We analyzed the genetic diversity and temporal and spatial distribution patterns of genetic variation of the host insects throughout the O. sinensis distribution. Abundant haplotype and nucleotide diversity mainly existed in the areas of Nyingchi, ShangriLa, and around the edge of the Qinghai-Tibet Plateau, where are considered as the diversity center or micro-refuges of the host insects of O. sinensis. However, there was little genetic variation among host insects from 72.1% of all populations, indicating that the host species composition might be relatively simple in large-scale O. sinensis populations. All host insects are monophyletic except for those from four O. sinensis populations around Qinghai Lake. Significant phylogeographic structure (NST>GST, P<0.05) was revealed for the monophyletic host insects, and the three major phylogenetic groups corresponded with specific geographical areas. The divergence of most host insects was estimated to have occurred at ca. 3.7 Ma, shortly before the rapid uplift of the QTP. The geographical distribution and star-like network of the haplotypes implied that most host insects were derived from the relicts of a once-widespread host that subsequently became fragmented. Neutrality tests, mismatch distribution analysis, and expansion time estimation confirmed that most host insects presented recent demographic expansions that began ca. 0.118 Ma in the late Pleistocene. Therefore, the genetic diversity and distribution of the present-day insects should be attributed to effects of the Qinghai-Tibet Plateau uplift and glacial advance/retreat cycles during the Quaternary ice age. These results provide valuable information to guide the protection and sustainable use of these host insects as well as O. sinensis.

[Spatial and Temporal Variations in Spectrum-Derived Vegetation Growth Trend in Qinghai-Tibetan Plateau from 1982 to 2014].

PubMed

Wang, Zhi-wei; Wu, Xiao-dong; Yue, Guang-yang; Zhao, Lin; Wang, Qian; Nan, Zhuo-tong; Qin, Yu; Wu, Tong-hua; Shi, Jian-zong; Zou, De-fu

2016-02-01

Recently considerable researches have focused on monitoring vegetation changes because of its important role in regula- ting the terrestrial carbon cycle and the climate system. There were the largest areas with high-altitudes in the Qinghai-Tibet Plateau (QTP), which is often referred to as the third pole of the world. And vegetation in this region is significantly sensitive to the global warming. Meanwhile NDVI dataset was one of the most useful tools to monitor the vegetation activity with high spatial and temporal resolution, which is a normalized transform of the near-infrared radiation (NIR) to red reflectance ratio. Therefore, an extended GIMMS NDVI dataset from 1982-2006 to 1982-2014 was presented using a unary linear regression by MODIS dataset from 2000 to 2014 in QTP. Compared with previous researches, the accuracy of the extended NDVI dataset was improved again with consideration the residuals derived from scale transformation. So the model of extend NDVI dataset could be a new method to integrate different NDVI products. With the extended NDVI dataset, we found that in growing season there was a statistically significant increase (0.000 4 yr⁻¹, r² = 0.585 9, p < 0.001) in QTP from 1982 to 2014. During the study pe- riod, the trends of NDVI were significantly increased in spring (0.000 5 yr⁻¹, r² = 0.295 4, p = 0.001), summer (0.000 3 yr⁻¹, r² = 0.105 3, p = 0.065) and autumn respectively (0.000 6 yr⁻¹, r² = 0.436 7, p < 0.001). Due to the increased vegeta- tion activity in Qinghai-Tibet Plateau from 1982 to 2014, the magnitude of carbon sink was accumulated in this region also at this same period. Then the data of temperature and precipitation was used to explore the reason of vegetation changed. Although the trends of them are both increased, the correlation between NDVI and temperature is higher than precipitation in vegetation grow- ing season, spring, summer and autumn. Furthermore, there is significant spatial heterogeneity of the changing trends for ND- VI, temperature and precipitation at Qinghai-Tibet Plateau scale.

[The epidemiology and etiology research of Tibetan sheep plague in Qinghai plateau].

PubMed

Wei, Baiqing; Xiong, Haoming; Yang, Xiaoyan; Yang, Yonghai; Qi, Meiying; Jin, Juan; Xin, Youquan; Li, Xiang; Yang, Hanqing; Han, Xiumin; Dai, Ruixia

2015-03-01

To identify the epidemiology and etiology characteristics of Tibetan sheep plague in Qinghai plateau. The background materials of Qinghai Tibetan sheep plague found during 1975 to 2009 were summarized, the regional, time and interpersonal distribution, infection routes, ecological factors for the spread were used to analyze; followed by choosing 14 Yersinia pestis strains isolated from such sheep for biochemical test, toxicity test, virulence factors identification, plasmid analysis, and DFR genotype. From 1975 to 2009, 14 Yersinia pestis strains were isolated from Tibetan sheep in Qinghai province. Tibetan sheep, as the infection source, had caused 10 cases of human plague, 25 plague patients, and 13 cases of death. All of the initial cases were infected due to eating Tibetan sheep died of plague; followed by cases due to contact of plague patients, while all the initial cases were bubonic plague. Cases of bubonic plague developed into secondary pneumonic plague and septicemia plague were most popular and with high mortality. Most of the Tibetan sheep plague and human plague occurred in Gannan ecological zone in southern Gansu province, which was closely related to its unique ecological and geographical landscape. Tibetan sheep plague coincided with human plague caused by Tibetan sheep, especially noteworthy was that November (a time for marmots to start their dormancy) witnesses the number of Yersinia pestis strains isolated from Tibetan sheep and human plague cases caused by Tibetan sheep. This constituted the underlying cause that the epidemic time of Tibetan sheep plague lags obviously behind that of the Marmot plague. It was confirmed in the study that all the 14 strains were of Qinghai-Tibet Plateau ecotype, with virulence factors evaluation and toxicity test demonstrating strains as velogenic. As found in the (Different Region) DFR genotyping, the strains isolated from Yushu county and Zhiduo county were genomovar 5, the two strain isolated from Nangqian county were genomovar 5 and genomovar 7, while those isolated Delingha region were genomovar 8. Tibetan sheep were vulnerable to plague infection, hence causing human plague as the infectious source. The Yersinia pestis strains isolated from Tibetan sheep plague carried pathogen characteristics of Qinghai-Tibet plateau plague, developing many new characteristics of such plague.

Precipitation change and its effects on prehistorical human activities in the Gonghe Basin, Northeastern Qinghai-Tibet Plateau during middle and late Holocene

NASA Astrophysics Data System (ADS)

Hou, Xiaoqing; Hou, Guangliang; Wang, Fangfang; Wang, Qingbo

2018-02-01

Northeastern Qinghai-tibet Plateau is considered as the ideal region for study of the climate change during the Holocene. Based on the meteorological data, the surface & fossil pollen data, this paper reconstructed the precipitation series of the region since middle Holocene with the GIS and MAT techniques, and discussed its relationship with prehistorical human activities. The results indicate that there are four major climatic phases: (I) Middle Holocene Humid Phase (6300-5000 aBP), with the primitive millet-farming first imported into the region; (II) Late Middle Holocene Sub-humid Phase (5000-3900 aBP), with the millet-farming spread rapidly within the region; (III) Late Holocene Fluctuation Phase (3900-2900 aBP), with the mean annual precipitation dropped down to lower than 240 mm, and a production mode-shift to a combination of cropping and husbandry; (IV) Late Holocene Stationary Phase (2900-0 aBP), with a precipitation alike the modern time, and a steady farming-pastoral economic pattern.

The complete mitochondrial genome sequence of the Tibetan red fox (Vulpes vulpes montana).

PubMed

Zhang, Jin; Zhang, Honghai; Zhao, Chao; Chen, Lei; Sha, Weilai; Liu, Guangshuai

2015-01-01

In this study, the complete mitochondrial genome of the Tibetan red fox (Vulpes Vulpes montana) was sequenced for the first time using blood samples obtained from a wild female red fox captured from Lhasa in Tibet, China. Qinghai--Tibet Plateau is the highest plateau in the world with an average elevation above 3500 m. Sequence analysis showed it contains 12S rRNA gene, 16S rRNA gene, 22 tRNA genes, 13 protein-coding genes and 1 control region (CR). The variable tandem repeats in CR is the main reason of the length variability of mitochondrial genome among canide animals.

Natural Selection and Adaptive Evolution of Leptin in the Ochotona Family Driven by the Cold Environmental Stress

PubMed Central

Yang, Jie; Wang, Zhen Long; Zhao, Xin Quan; Wang, De Peng; Qi, De Lin; Xu, Bao Hong; Ren, Yong Hong; Tian, Hui Fang

2008-01-01

Background Environmental stress can accelerate the evolutionary rate of specific stress-response proteins and create new functions specialized for different environments, enhancing an organism's fitness to stressful environments. Pikas (order Lagomorpha), endemic, non-hibernating mammals in the modern Holarctic Region, live in cold regions at either high altitudes or high latitudes and have a maximum distribution of species diversification confined to the Qinghai-Tibet Plateau. Variations in energy metabolism are remarkable for them living in cold environments. Leptin, an adipocyte-derived hormone, plays important roles in energy homeostasis. Methodology/Principal Findings To examine the extent of leptin variations within the Ochotona family, we cloned the entire coding sequence of pika leptin from 6 species in two regions (Qinghai-Tibet Plateau and Inner Mongolia steppe in China) and the leptin sequences of plateau pikas (O. curzonia) from different altitudes on Qinghai-Tibet Plateau. We carried out both DNA and amino acid sequence analyses in molecular evolution and compared modeled spatial structures. Our results show that positive selection (PS) acts on pika leptin, while nine PS sites located within the functionally significant segment 85-119 of leptin and one unique motif appeared only in pika lineages-the ATP synthase α and β subunit signature site. To reveal the environmental factors affecting sequence evolution of pika leptin, relative rate test was performed in pikas from different altitudes. Stepwise multiple regression shows that temperature is significantly and negatively correlated with the rates of non-synonymous substitution (Ka) and amino acid substitution (Aa), whereas altitude does not significantly affect synonymous substitution (Ks), Ka and Aa. Conclusions/Significance Our findings support the viewpoint that adaptive evolution may occur in pika leptin, which may play important roles in pikas' ecological adaptation to extreme environmental stress. We speculate that cold, and probably not hypoxia, may be the primary environmental factor for driving adaptive evolution of pika leptin. PMID:18213380

Genetic variation within and among populations of Rhodiola alsia (Crassulaceae) native to the Tibetan Plateau as detected by ISSR markers.

PubMed

Xia, Tao; Chen, Shilong; Chen, Shengyun; Ge, Xuejun

2005-04-01

Genetic variation of 10 Rhodiola alsia (Crassulaceae) populations from the Qinghai-Tibet Plateau of China was investigated using intersimple sequence repeat (ISSR) markers. R. alsia is an endemic species of the Qinghai-Tibet Plateau. Of the 100 primers screened, 13 were highly polymorphic. Using these primers, 140 discernible DNA fragments were generated with 112 (80%) being polymorphic, indicating pronounced genetic variation at the species level. Also there were high levels of polymorphism at the population level with the percentage of polymorphic bands (PPB) ranging from 63.4 to 88.6%. Analysis of molecular variance (AMOVA) showed that the genetic variation was mainly found among populations (70.3%) and variance within populations was 29.7%. The main factors responsible for the high level of differentiation among populations are probably the isolation from other populations and clonal propagation of this species. Occasional sexual reproduction might occur in order to maintain high levels of variation within populations. Environmental conditions could also influence population genetic structure as they occur in severe habitats. The strong genetic differentiation among populations in our study indicates that the conservation of genetic variability in R. alsia requires maintenance of as many populations as possible.

[Climate change impacts on yield of Cordyceps sinensis and research on yield prediction model of C. sinensis].

PubMed

Zhu, Shou-Dong; Huang, Lu-Qi; Guo, Lan-Ping; Ma, Xing-Tian; Hao, Qing-Xiu; Le, Zhi-Yong; Zhang, Xiao-Bo; Yang, Guang; Zhang, Yan; Chen, Mei-Lan

2017-04-01

Cordyceps sinensis is a Chinese unique precious herbal material, its genuine producing areas covering Naqu, Changdu in Qinghai Tibet Plateau, Yushu in Qinghai province and other regions. In recent 10 years, C. sinensis resources is decreasing as a result of the blindly and excessively perennial dug. How to rationally protect, develop and utilize of the valuable resources of C. sinensis has been referred to an important field of research on C. sinensis. The ecological environment and climate change trend of Qinghai Tibet plateau happens prior to other regions, which means that the distribution and evolution of C. sinensis are more obvious and intense than those of the other populations. Based on RS (remote sensing)/GIS(geographic information system) technology, this paper utilized the relationship between the snowline elevation, the average temperature, precipitation and sunshine hours in harvest period (April and may) of C. sinensis and the actual production of C. sinensis to establish a weighted geometric mean model. The model's prediction accuracy can reach 82.16% at least in forecasting C. sinensis year yield in Naqu area in every early June. This study can provide basic datum and information for supporting the C. sinensis industry healthful, sustainable development. Copyright© by the Chinese Pharmaceutical Association.

[Effects of human engineering activities on permafrost active layer and its environment in northern Qinghai-Tibetan plateau].

PubMed

Guo, Zhenggang; Wu, Qingbo; Niu, Fujun

2006-11-01

With disturbed and undisturbed belts during the construction of Qinghai-Tibet highway as test objectives, this paper studied the effects of human engineering activities on the permafrost ecosystem in northern Qinghai-Tibetan plateau. The results showed that the thickness of permafrost active layer was smaller in disturbed than in undisturbed belt, and decreased with increasing altitude in undisturbed belt while no definite pattern was observed in disturbed belt. Different vegetation types had different effects on the thickness of permafrost active layer, being decreased in the order of steppe > shrub > meadow. In the two belts, altitude was the main factor affecting the vertical distribution of soil moisture, but vegetation type was also an important affecting factor if the altitude was similar. Due to the human engineering activities, soil temperature in summer was lower in disturbed than in undisturbed belt.

Girls First! Promoting Early Education in Tibetan Areas of China, a Case Study

ERIC Educational Resources Information Center

Seeberg, Vilma

2008-01-01

This study explores conditions promoting girls' education in ethnic Tibetan pastoral highlands of the Qinghai-Tibet plateau of western China. Global discourse and cross national evidence on the transgenerational benefits of girls' education has shown prioritizing girls' education to be the most effective strategy of breaking the vicious cycle of…

The aliphatic hydrocarbon distributions of terrestrial plants around an alpine lake: a pilot study from Lake Ximencuo, Eastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Pu, Yang; Jia, Jihong; Cao, Jicheng

2017-12-01

As part of an investigation of the sources of aliphatic hydrocarbons to the sediments of alpine Lake Ximencuo, leaves of the eight dominant vascular plants were collected and their hydrocarbon contents were analyzed. A series of unsaturated aliphatic hydrocarbons were identified in the plant leaves; in particular, Festuca sp. contain a series of n-alkadienes that have rarely been reported in previous studies. The comparison of n-alkane proxies (ACL 27-33, ACL T, P aq, and CPI) and δ13Corg among plant leaves, surface soils, and lake sediments suggests that organic proxies have been altered to varying degrees during the transport and burial process of organic materials. It is believed that microbial reworking and source changes have great impacts on organic proxies in the alpine lake system. In addition, the cluster analysis for plant leaves depending on n-alkane compositions and the ACL T proxy generates similar results. Accordingly, we postulate that the average chain length of plant waxes might be a potential indicator of plant classification in regions such as the Qinghai-Tibet Plateau.

Diversity and community structure of fungi through a permafrost core profile from the Qinghai-Tibet Plateau of China.

PubMed

Hu, Weigang; Zhang, Qi; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; An, Lizhe; Feng, Huyuan

2014-12-01

While a vast number of studies have addressed the prokaryotic diversity in permafrost, characterized by subzero temperatures, low water activity, and extremely low rates of nutrient and metabolite transfer, fungal patterns have received surprisingly limited attention. Here, the fungal diversity and community structure were investigated by culture-dependent technique combined with cloning-restriction fragment length polymorphism (RFLP) analysis of sediments in a 10-m-long permafrost core from the Qinghai-Tibet Plateau of China. A total of 62 fungal phylotypes related to 10 distinct classes representing three phyla were recovered from 5031 clones generated in 13 environmental gene libraries. A large proportion of the phylotypes (25/62) that were distantly related to described fungal species appeared to be novel diversity. Ascomycota was the predominant group of fungi, with respect to both clone and phylotype number. Our results suggested there was the existence of cosmopolitan psychrophilic or psychrotolerant fungi in permafrost sediments, the community composition of fungi varied with increasing depth, while these communities largely distributed according to core layers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Seasonal changes in adrenocortical responses to acute stress in Eurasian tree sparrow (Passer montanus) on the Tibetan Plateau: comparison with house sparrow (P. domesticus) in North America and with the migratory P. domesticus in Qinghai Province.

PubMed

Li, Dongming; Wang, Gang; Wingfield, John C; Zhang, Zhi; Ding, Changqing; Lei, Fumin

2008-08-01

Seasonal modulation of the adrenocortical response to stress appears to be ubiquitous in arctic-breeding and temperate-zone-breeding birds, but has not been well investigated in alpine-breeding species at mid-latitude. We examined the adrenocortical response to acute stress (capture, handling and restraint) in populations of Eurasian tree sparrow (Passer montanus) among seasons and migratory house sparrow (P. domesticus bactrianus) in pre-breeding on the Qinghai-Xizang Plateau (the Tibetan Plateau). A population of house sparrow (Passer domesticus domesticus) was also sampled in lowland Phoenix, Arizona during breeding and wintering stages. In Eurasian tree sparrows, baseline corticosterone (CORT) does not differ among life history stages, but stress-induced CORT level (maximal CORT, total and corrected integrated CORT) is significantly higher in late breeding stage than those in early breeding and prebasic molt stages. In house sparrows, stress-induced CORT level does not differ between sites and life history stages, but baseline CORT is significantly lower in pre-breeding from Qinghai compared with those in breeding and wintering stages from Phoenix. Interestingly, both baseline CORT and maximal CORT do not differ between the populations of Eurasian tree sparrow and house sparrow in early/pre-breeding stage although tree sparrow is resident species whereas house sparrow is migratory in Qinghai. Our results suggest that the extreme environment of the Tibetan Plateau does not have significant effects on adrenocortical responses to acute stress in Eurasian tree sparrows and house sparrows, which may be a result of masking by human activities. These invasive human commensals may have a unique HPA axis response to different environments because they can take advantage of human food sources and shelter (i.e. buildings).

The burying and grazing effects of plateau pika on alpine grassland are small: a pilot study in a semiarid basin on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Yi, Shuhua; Chen, Jianjun; Qin, Yu; Xu, Gaowei

2016-11-01

There is considerable controversy about the effects of plateau pika (Ochotona curzoniae, hereafter pika) on alpine grassland on the Qinghai-Tibet Plateau (QTP). On the one hand, pika is considered a keystone species. On the other hand, it is being poisoned. Although significant efforts have been made to study the effects of pika at a quadrat scale ( ˜ m2), our knowledge about its distribution and effects at a larger scale is very limited. In this study, we investigated the direct effects, i.e., burying and grazing, of pika by upscaling field sampling at a quadrat scale to a plot scale ( ˜ 1000 m2) by aerial photographing. Altogether 168 plots were set on four different types of alpine grassland in a semiarid basin on the QTP. Results showed that (1) the effects of pika pile burying on the reduction of vegetation cover, biomass, soil carbon, and nitrogen were less than 10 %, which was much smaller than the effects of bald patches; and (2) pika consumed 8-21 % of annual net primary production of grassland. We concluded that the direct burying and grazing effects of pika on alpine grassland were minor in this region. The quadcopter is an efficient and economic tool for long-term repeated monitoring over large regions for further understanding the role of pika.

Impact of a thermokarst lake on the soil hydrological properties in permafrost regions of the Qinghai-Tibet Plateau, China.

PubMed

Gao, Zeyong; Niu, Fujun; Wang, Yibo; Luo, Jing; Lin, Zhanju

2017-01-01

The formation of thermokarst lakes can degrade alpine meadow ecosystems through changes in soil water and heat properties, which might have an effect on the regional surface water and groundwater processes. In this study, a typical thermokarst lake was selected in the Qinghai-Tibet Plateau (QTP), and the ecological index (S L ) was used to divide the affected areas into extremely affected, severely affected, medium-affected, lightly affected, and non-affected areas, and soil hydrological properties, including saturated hydraulic conductivity and soil water-holding capacity, were investigated. The results showed that the formation of a thermokarst lake can lead to the degradation of alpine meadows, accompanied by a change in the soil physiochemical and hydrological properties. Specifically, the soil structure turned towards loose soil and the soil nutrients decreased from non-affected areas to severely affected areas, but the soil organic matter and available potassium increased slightly in the extremely affected areas. Soil saturated hydraulic conductivity showed a 1.7- to 4.1-fold increase in the lake-surrounding areas, and the highest value (401.9cmd -1 ) was detected in the severely affected area. Soil water-holding capacity decreased gradually during the transition from the non-affected areas to the severely affected areas, but it increased slightly in the extremely affected areas. The principal component analysis showed that the plant biomass was vital to the changes in soil hydrological properties. Thus, the vegetation might serve as a link between the thermokarst lake and soil hydrological properties. In this particular case, it was concluded that the thermokarst lake adversely affected the regional hydrological services in the alpine ecosystem. These results would be useful for describing appropriate hydraulic parameters with the purpose of modeling soil water transportation more accurately in the Qinghai-Tibet Plateau. Copyright © 2016 Elsevier B.V. All rights reserved.

Monitoring of aeolian desertification on the Qinghai-Tibet Plateau from the 1970s to 2015 using Landsat images.

PubMed

Zhang, Chun-Lai; Li, Qing; Shen, Ya-Ping; Zhou, Na; Wang, Xue-Song; Li, Jiao; Jia, Wen-Ru

2018-04-01

Aeolian desertification, one of the most serious environmental issues, has hampered socioeconomic development on the Qinghai-Tibet Plateau (QTP). However, research on aeolian desertification in this region has been limited. To develop a set of science-based preventive measures to mitigate desertification in this region, it is first necessary to clarify the status, evolution, and driving factors of aeolian desertification. In this study, based on extensive field investigations and a current classification system for aeolian desertification, we established a new system for interpreting aeolian desertified land (ADL) on the plateau using Landsat images from 1977, 1990, 2000, 2010, and 2015 and obtained the distribution of ADL through visual interpretation of the images. The results showed that ADL covered 392,914km 2 (15.1% of the study area) in 2015, including gravel ADL, sandy ADL, and aeolian monadnocks. Controlled by climate, landforms, the type of Quaternary deposit, and human activities, ADL is scattered throughout the plateau but is concentrated mostly in the western and northern parts. Aeolian desertification on the plateau expanded from 1977 to 2000 and then began to reverse. The evolution during the study period is the result of the combined effects of natural and human factors. Irrational human activities were the dominant factor responsible for the expansion of ADL prior to 2000, whereas the subsequent reversal was mainly caused by climate change combined with large ecological restoration projects. Copyright © 2017 Elsevier B.V. All rights reserved.

The Influence Analysis of the Rainfall Meteorological Conditions on the Operation of the Balloon Borne Radar in Plateau

NASA Astrophysics Data System (ADS)

Li, Qiong; Geng, Fangzhi

2018-03-01

Based on the characteristics of complex terrain and different seasons’ weather in Qinghai Tibet Plateau, through statistic the daily rainfall that from 2002 to 2012, nearly 11 years, by Bomi meteorological station, Bomi area rainfall forecast model is established, and which can provide the basis forecasting for dangerous weather warning system on the balloon borne radar in the next step, to protect the balloon borne radar equipment’s safety work and combat effectiveness.

Prevalence, Associated Risk Factors, and Phylogenetic Analysis of Toxocara vitulorum Infection in Yaks on the Qinghai Tibetan Plateau, China

PubMed Central

Li, Kun; Lan, Yanfang; Luo, Houqiang; Zhang, Hui; Liu, Dongyu; Zhang, Lihong; Gui, Rui; Wang, Lei; Shahzad, Muhammad; Sizhu, Suolang; Li, Jiakui; Chamba, Yangzom

2016-01-01

Toxocara vitulorum has been rarely reported in yaks at high altitudes and remote areas of Sichuan Province of Tibetan Plateau of China. The current study was designed to investigate the prevalence, associated risk factors, and phylogenetic characteristics of T. vitulorum in yak calves on the Qinghai Tibetan plateau. Fecal samples were collected from 891 yak calves and were examined for the presence of T. vitulorum eggs by the McMaster technique. A multivariable logistic regression model was employed to explore variables potentially associated with exposure to T. vitulorum infection. T. vitulorum specimens were collected from the feces of yaks in Hongyuan of Sichuan Province, China. DNA was extracted from ascaris. After PCR amplification, the sequencing of ND1 gene was carried out and phylogenetic analyses was performed by MEGA 6.0 software. The results showed that 64 (20.1%; 95% CI 15.8–24.9%), 75 (17.2; 13.8–21.1), 29 (40.9; 29.3–53.2), and 5 (7.6; 2.5–16.8) yak calves were detected out to excrete T. vitulorum eggs in yak calve feces in Qinghai, Tibet, Sichuan, and Gansu, respectively. The present study revealed that high infection and mortality by T. vitulorum is wildly spread on the Qinghai Tibetan plateau, China by fecal examination. Geographical origin, ages, and fecal consistencies are the risk factors associated with T. vitulorum prevalence by logistic regression analysis. Molecular detection and phylogenetic analysis of ND1 gene of T. vitulorum indicated that T. vitulorum in the yak calves on the Qinghai Tibetan plateau are homologous to preveiously studies reported. PMID:27853122

Preparation and thermal properties of Glauber’s salt-based phase-change materials for Qinghai-Tibet Plateau solar greenhouses

NASA Astrophysics Data System (ADS)

Jiang, Zipeng; Tie, Shengnian

2017-07-01

This paper reports the preparation and characterization of eutectic Glauber’s salt-based composite, phase-change materials (G-PCMs). PCMs were prepared using industrial-grade sodium sulfate decahydrate (Na2SO4 ṡ 10H2O) as the basic material. Other salts were added to obtain the eutectic Glauber’s salt-based PCMs with phase-change temperatures of 25∘C, 15∘C and 10∘C. The modification of the G-PCMs was designed using the same experimental method to select the efficient nucleating, thickening and thermal conductive agents. The results show that borax can be an effective nucleating agent, sodium carboxymethyl cellulose is an excellent thickener and carbon powder is a good thermal conductive agent. The phase-change temperature, latent heat and thermal conductivity of the three different PCMs are 23.9∘C, 15.4∘C and 9.5∘C; 179.6, 129 and 116.2 J/g; and 1.02, 1.10 and 1.23 W/(m K), respectively. These PCMs possess suitable phase-change temperature, high latent heat and good thermal conductivity, and can be used in Qinghai-Tibet Plateau agricultural solar greenhouses.

Photo-protective mechanisms in reed canary grass to alleviate photo-inhibition of PSII on the Qinghai-Tibet Plateau.

PubMed

Zhang, Chao; Zhang, Da-Wei; Sun, Yan-Ni; Arfan, Muhammad; Li, Da-Xu; Yan, Jia-Jun; You, Ming-Hong; Bai, Shi-Qie; Lin, Hong-Hui

2017-08-01

Due to its characteristic of high biomass yield potential, there is considerable interest in cultivating Phalaris arundinacea L. cv. 'chuancaoyin No.3' (reed canary grass) on the Qinghai-Tibet Plateau where there is an abundance of alpine steppe meadow and a potential large market for animal husbandry. In this study, we 1) investigate whether reed canary grass exhibits superior productive capacity to Elymus nutans 'Aba' (E. nutans), ordinary common pasture, during the long warm days of summer at high-altitude; and 2) compare the cold tolerance between reed canary grass and E. nutans, including photosynthesis, photo-inhibition, and photo-protection. The results suggest that reed canary grass exhibits higher photosynthetic capacity compared to E. nutans at latitudes of the cool temperate zone. Meanwhile, cold-induced photo-inhibition and photo-damage at high altitudes in reed canary grass were due to both stomatal and non-stomatal limitation, and the enhancement in photo-respiration, thermal dissipation, and Mehler reaction are important processes to minimize the negative effects of high elevation and a cold environment. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Flower evolution of alpine forbs in the open top chambers (OTCs) from the Qinghai-Tibet Plateau.

PubMed

Zhang, Chan; Wang, Lin-Lin; Yang, Yong-Ping; Duan, Yuan-Wen

2015-05-22

Effects of global changes on biodiversity have been paid more and more attention world widely, and the open top chambers (OTCs) are the most common tools to study the effects of climatic warming on plant diversity. However, it remains unclear how flowers evolve under environmental changes, which could help us to understand the changes of plant diversity in the OTCs. We compared the insect diversity and pollen:ovule (P/O) ratio of eight outcrossing species with different life histories inside and outside the OTCs on the Qinghai-Tibet Plateau, to examine the effects induced by OTCs on the evolution of floral traits. In the OTCs, P/O ratio decreased in annuals, but increased in perennials, indicating an overall trend toward selfing in annuals. We found that the insect diversity differed significantly inside and outside the OTCS, with decreases of dipteran insects and bees. We concluded that changes of P/O ratio in the studied plant species might result from pollination failure, which might be the results of mismatch between flowering time and pollinator activities. We also suggested annuals might be in a more extinction risk than perennials in OTCs, if strong inbreeding depression occurs in these annual outcrossing plants.

Temperature sensitivity of gaseous elemental mercury in the active layer of the Qinghai-Tibet Plateau permafrost.

PubMed

Ci, Zhijia; Peng, Fei; Xue, Xian; Zhang, Xiaoshan

2018-07-01

Soils represent the single largest mercury (Hg) reservoir in the global environment, indicating that a tiny change of Hg behavior in soil ecosystem could greatly affect the global Hg cycle. Climate warming is strongly altering the structure and functions of permafrost and then would influence the Hg cycle in permafrost soils. However, Hg biogeochemistry in climate-sensitive permafrost is poorly investigated. Here we report a data set of soil Hg (0) concentrations in four different depths of the active layer in the Qinghai-Tibet Plateau permafrost. We find that soil Hg (0) concentrations exhibited a strongly positive and exponential relationship with temperature and showed different temperature sensitivity under the frozen and unfrozen condition. We conservatively estimate that temperature increases following latest temperature scenarios of the IPCC could result in up to a 54.9% increase in Hg (0) concentrations in surface permafrost soils by 2100. Combining the simultaneous measurement of air-soil Hg (0) exchange, we find that enhanced Hg (0) concentrations in upper soils could favor Hg (0) emissions from surface soil. Our findings indicate that Hg (0) emission could be stimulated by permafrost thawing in a warmer world. Copyright © 2018 Elsevier Ltd. All rights reserved.

Application of UTCI in China from tourism perspective

NASA Astrophysics Data System (ADS)

Ge, Quansheng; Kong, Qinqin; Xi, Jianchao; Zheng, Jingyun

2017-05-01

This study uses ERA-Interim reanalysis data and the Universal Thermal Climate Index (UTCI) to investigate the spatial pattern of thermal bioclimatic conditions in China. Our results show that the annual UTCI increases with decreasing latitude throughout most of China. Areas that experience "no thermal stress" are located southeast of the line formed by the Yanshan Mountains, Taihang Mountains, the southern edge of the Loess Plateau, and the eastern edge of the Qinghai-Tibet Plateau, with an area of 312.83e4 km2. During spring and autumn, the UTCI distribution is similar to the annual distribution. During summer, areas with "no thermal stress" cover the largest area (563.55e4 km2), including northern and southwestern China; in contrast, during winter, areas with "no thermal stress" only occur south of the Nanling Mountains. The annual number of days with "no thermal stress" increases from north to south in central and eastern China, exceeding 200 days in the Sichuan Basin, the southeastern coastal regions and the Yungui Plateau. The minimum and maximum values occur on the Qinghai-Tibet Plateau (≤10 days) and the southern Yungui Plateau (>280 days). Seasonal analysis indicates that there are over 70 days with "no thermal stress" in the Sichuan Basin, the Yungui Plateau and the middle and lower reaches of the Yangtze River during spring and autumn, while there are more than 80 days in northern and southwestern China during summer and over 80 days in areas south of the Nanling Mountains during winter. The results of this study can be helpful for optimization of the tourism industry and tourism destinations development in China.

Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands.

PubMed

Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

2015-01-01

Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q10), and activation energy (Ea). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the Ea values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between Ea and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau.

Monitoring the lake area changes of the Qinghai-Tibet Plateau using coarse-resolution time series remote sensing data

NASA Astrophysics Data System (ADS)

Ma, M.

2015-12-01

The Qinghai-Tibet Plateau (QTP) is the world's highest and largest plateau and is occasionally referred to as "the roof of the world". As the important "water tower", there are 1,091 lakes of more than 1.0 km2 in the QTP areas, which account for 49.4% of the total area of lakes in China. Some studies focus on the lake area changes of the QTP areas, which mainly use the middle-resolution remote sensing data (e.g. Landsat TM). In this study, the coarse-resolution time series remote sensing data, MODIS data at a spatial resolution of 250m, was used to monitor the lake area changes of the QTP areas during the last 15 years. The dataset is the MOD13Q1 and the Normal Difference Vegetation Index (NDVI) is used to identify the lake area when the NDVI is less than 0. The results show the obvious inner-annual changes of most of the lakes. Therefore the annually average and maximum lake areas are calculated based on the time series remote data, which can better quantify the change characteristics than the single scene of image data from the middle-resolution data. The results indicate that there are big spatial variances of the lake area changes in the QTB. The natural driving factors are analyzed for revealing the causes of changes.

Interactions between Lakes and the Atmosphere over the Largest High-Altitude Saline Lake on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, X.

2017-12-01

Interactions between lakes and the atmosphere at high-altitudes are still poorly understood due to difficulty in accessibility of direct measurements. This is particularly true for the Qinghai-Tibet Plateau (QTP), where approximately 50% of the lakes in China are located. Continuous direct measurements of the water flux and surface energy budget were made over the largest high-altitude saline lake in China, Qinghai Lake on the northeastern QTP, using the eddy covariance (EC) method from 11 May, 2013 through 10 May, 2015. Results indicated that net radiation and heat storage showed consistent diurnal variation with positive values in the daytime and negative values at night, while latent and sensible heat flux showed little diurnal variation. Nocturnal λE and H contributed to 47.7% and 29.0% of the total heat loss, during the two- year study period. Annual evaporation of Qinghai Lake was 832.5 mm for 2013/2014 and 823.6 mm for 2014/2015, respectively. The surface energy budget and evaporation showed a strong seasonal pattern, with peaks in the latent and sensible heat flux observed in autumn and early winter. There was a 2-3 month delay between the maximum net radiation and maximum latent and sensible heat fluxes. Intraseasonal and seasonal variations in latent and sensible heat flux were strongly affected by different air masses. Westerly cold and dry air masses increased evaporation while southeast moist air mass suppressed evaporation, suggesting that the lakes might serve as an 'air-conditioner' to modify the temporal heat and water flux in QTP. Latent heat flux (λE) during the ice-covered period was less than that during the ice-free period, and lake ice sublimation is perhaps a main possible source for λE during the freeze-up period.

Isolation of microsatellite loci for Rhodiola alsia (Crassulaceae), an important ethno-medicinal herb endemic to the Qinghai-Tibetan plateau.

PubMed

Zhang, F Q; Lei, S Y; Gao, Q B; Khan, G; Xing, R; Yang, H L; Chen, S L

2015-05-18

Rhodiola alsia, which has been used widely in traditional Chinese medicine for a considerable time, grows on moist habitats at high altitude near the snow line. Microsatellite loci were developed for R. alsia to investigate its population genetics. In total, 17 polymorphic microsatellites were developed based on ESTs from the Illumina HiSeq(TM) 2000 platform. The microsatellite loci were checked for variability using 80 individuals of R. alsia sampled from four locations on the Qinghai-Tibet Plateau. The total number of alleles per locus ranged from 10 to 20, and the observed heterozygosity ranged from 0.000 to 1.000. The null allele frequency ranged from 0.000 to 0.324. These microsatellites are expected to be helpful in future studies of population genetics in R. alsia and related species.

Vegetation Response to Climate Change in the Southern Part of Qinghai-Tibet Plateau at Basinal Scale

NASA Astrophysics Data System (ADS)

Liu, X.; Liu, C.; Kang, Q.; Yin, B.

2018-04-01

Global climate change has significantly affected vegetation variation in the third-polar region of the world - the Qinghai-Tibet Plateau. As one of the most important indicators of vegetation variation (growth, coverage and tempo-spatial change), the Normalized Difference Vegetation Index (NDVI) is widely employed to study the response of vegetation to climate change. However, a long-term series analysis cannot be achieved because a single data source is constrained by time sequence. Therefore, a new framework was presented in this paper to extend the product series of monthly NDVI, taking as an example the Yarlung Zangbo River Basin, one of the most important river basins in the Qinghai-Tibet Plateau. NDVI products were acquired from two public sources: Global Inventory Modeling and Mapping Studies (GIMMS) Advanced Very High Resolution Radiometer (AVHRR) and Moderate-Resolution Imaging spectroradiometer (MODIS). After having been extended using the new framework, the new time series of NDVI covers a 384 months period (1982-2013), 84 months longer than previous time series of NDVI product, greatly facilitating NDVI related scientific research. In the new framework, the Gauss Filtering Method was employed to filter out noise in the NDVI product. Next, the standard method was introduced to enhance the comparability of the two data sources, and a pixel-based regression method was used to construct NDVI-extending models with one pixel after another. The extended series of NDVI fit well with original AVHRR-NDVI. With the extended time-series, temporal trends and spatial heterogeneity of NDVI in the study area were studied. Principal influencing factors on NDVI were further determined. The monthly NDVI is highly correlated with air temperature and precipitation in terms of climatic change wherein the spatially averaged NDVI slightly increases in the summer and has increased in temperature and decreased in precipitation in the 32 years period. The spatial heterogeneity of NDVI is in accordance with the seasonal variation of the two climate-change factors. All of these findings can provide valuable scientific support for water-land resources exploration in the third-polar region of the world.

Effect of the disturbance of plateau pika (Ochotona curzoniae) on soil water and soil temperature characteristics at Alpine Meadows in Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Ma, Yujun; Wu, Yinan; Wang, Xiaoxing; Li, Xiaoyan

2015-04-01

The plateau pika (Ochotona curzoniae) is one of main small rodents at Alpine Meadows in Qinghai-Tibet Plateau, and has a positive effect on the maintenance of regional soil biodiversity. But, its excessive disturbance was also known as an important factor that leads to the vegetation degradation. Based on the field experiment, sampling analysis and continuous observation, this study compared the difference of soil water and soil temperature characteristics at different disturbance stages, which included native grassland, new mound, old mound and bare land formed by old mound. The findings of this study revealed that, after the disturbance of plateau pika, the soil bulk density at the shallow layer (0-20 cm) increased with the time-lapse. At the 20-30 cm depth, the soil bulk density of old mound, bare land and native grassland were similar, and were all higher than that of new mound. At the deep layer (under 30 cm), the soil bulk density had no significant difference between four stages, which showed that the disturbance of plateau pika mainly distributed within the shallow 30 cm depth. The unsaturated hydraulic conductivity of new mound was higher than old mound, bare soil and native grassland, with the multiple of 3.08-8.71, 4.63-16.27 and 3.70-15.25, respectively, and led to the obvious variance of soil water change for different types of land surface. After the precipitation, the soil water content change of new mound and old mound were more significant than that of bare land and native grassland. Because of the disturbance of plateau pika, the soil temperature characteristics changed, too. The heat conductivity rate of new mound and old mound decreased, significantly, and their daily temperature difference were obvious higher than bare land and native grassland. These results were essential for the study of vegetation recovery after the disturbance of plateau pika.

Multi-Annual Data Products on Turbulent Heat Fluxes at the Local and Continental Scale Using AATSR and FY-2 Data

NASA Astrophysics Data System (ADS)

Menenti, M.; Ghafarian, H.; Tang, B.; Faivre, R.; Colin, J.; Jia, L.; Roupios, L.

2013-01-01

This paper summarizes the results of studies carried in the framework of the Dragon 2 Program - Project 5322 Key Eco-Hydrological Parameters Retrieval and Land Data Assimilation System Development in a Typical Inland River Basin of Chinas Arid Region. The investigations were focused on monitoring the fluxes of energy and water at the land-atmosphere interface across a range of spatial scales, using multi-spectral radiometric data collected by space-borne imaging radiometers. At the local scale a new approach to parameterize heat and vapour fluxes was developed and applied using Computational Fluid Dynamics to describe state and dynamics of the boundary layer over the heterogeneous and 3D structured land surface. An airborne scanning LIDAR was used to capture in detail surface geometry. Over the large area of the Qinghai-Tibet Plateau a land-atmospheric model was used to characterize the atmospheric Planetary Boundary Layer. The effect of land surface heterogeneity and structure on the exchange of heat and water was captured using the bi-angular observations of brightness temperature provided by the AATSR imaging radiometer. The heat and water flux densities were calculated hourly with Feng-Yun C, D and E VISSR data over the Qinghai-Tibet Plateau and the headwaters of main rivers around it.

Landform-related permafrost characteristics in the source area of the Yellow River, eastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, Jing; Sheng, Yu; Wu, Jichun; Feng, Ziliang; Ning, Zuojun; Hu, Xiaoying; Zhang, Xiumin

2016-09-01

The source area of the Yellow River (SAYR) lies in the eastern part of the Qinghai-Tibet Plateau (QTP). Glaciers are absent in the area, but permafrost is widespread because of the high elevations, typically 4200-5000 m a.s.l. Landforms in the SAYR were classified into seven basic types, based on their morphological characteristics and genesis, and further divided into 12 sub-classes based on geomorphic processes. Permafrost development and ground temperature in boreholes were analyzed on representative landforms in the SAYR. Permafrost was discontinuously distributed at 4300-4400 m a.s.l. in fluvial plains because of variations in local topography, sediments, vegetation and water content. In hills and low-relief mountains in the western part of the study area, permafrost is continuous above 4400 m a.s.l. even on unshaded south-facing slopes. In contrast, permafrost in the central part of the study area is discontinuous over this elevation range. Analysis of ground temperature measurements revealed that three macro-scale factors, latitude, longitude, and elevation, explain 72.8% of the variation in the measured mean annual ground temperature (MAGT). The remaining 27.2% can potentially be explained by variations in topography and land cover within the SAYR.

[Assessment on vegetation restoration capacity of several grassland ecosystems under destroyed disturbance in permafrost regions of Qinghai-Tibet Plateau].

PubMed

Li, Dong-Ming; Guo, Zheng-Gang; An, Li-Zhe

2008-10-01

Vegetation restoration capacity of disturbed grassland ecosystem is one of the important components in assessing the influence of human engineering activities on the grassland ecosystems in permafrost region of Qinghai-Tibet Plateau. After comparing the features of vegetation communities, plant species diversity, grassland primary productivity, and economic group between disturbed and undisturbed communities, the comprehensive vegetation restoration capacity of several grassland communities under destroyed disturbance was assessed by using comprehensive assessment index. The results showed that the restoration of cover and community composition was obvious after 26 years natural restoration, being better for alpine steppes than for alpine meadows. However, the cover of disturbed communities was less than that of undisturbed communities. The restoration of plant species diversity in Stipa purpurea steppe was better than that in other grassland types. The biomass of standing plants restored from 0 to 148.8-489.6 g x m(-2), and that of Kobresia tibetica meadow was the highest (489.6 g x m(-2)). The palatable plants of disturbed communities were lower than those of undisturbed communities except for K. tibetica meadow, in which, the palatable plants were not changeable between disturbed and undisturbed communities. The comprehensive vegetation restoration capacity of alpine steppes was better than that of alpine meadows.

Impact of naturally leaking carbon dioxide on soil properties and ecosystems in the Qinghai-Tibet plateau.

PubMed

Zhao, Xiaohong; Deng, Hongzhang; Wang, Wenke; Han, Feng; Li, Chunrong; Zhang, Hui; Dai, Zhenxue

2017-06-07

One of the major concerns for CO 2 capture and storage (CCS) is the potential risk of CO 2 leakage from storage reservoirs on the shallow soil property and vegetation. This study utilizes a naturally occurring CO 2 leaking site in the Qinghai-Tibet Plateau to analog a "leaking CCS site". Our observations from this site indicates that long-term CO 2 invasion in the vadose zone results in variations of soil properties, such as pH fluctuation, slight drop of total organic carbon, reduction of nitrogen and phosphorus, and concentration changes of soluble ions. Simultaneously, XRD patterns of the soil suggest that crystallization of soil is enhanced and mineral contents of calcite and anorthite in soil are increased substantially. Parts of the whole ecosystem such as natural wild plants, soil dwelling animals and microorganisms in shallow soil are affected as well. Under a moderate CO 2 concentration (less than 110000 ppm), wild plant growth and development are improved, while an intensive CO 2 flux over 112000 ppm causes adverse effects on the plant growth, physiological and biochemical system of plants, and crop quality of wheat. Results of this study provide valuable insight for understanding the possible environmental impacts associated with potential CO 2 leakage into shallow sediments at carbon sequestration sites.

Exploring the ground ice recharge near permafrost table on the central Qinghai-Tibet Plateau using chemical and isotopic data

NASA Astrophysics Data System (ADS)

Wang, Weihua; Wu, Tonghua; Zhao, Lin; Li, Ren; Zhu, Xiaofan; Wang, Wanrui; Yang, Shuhua; Qin, Yanhui; Hao, Junmin

2018-05-01

Thawing permafrost on the Qinghai-Tibet Plateau (QTP) has great impacts on the local hydrological process by way of causing ground ice to thaw. Until now there is little knowledge on ground ice hydrology near permafrost table under a warming climate. This study applied stable tracers (isotopes and chloride) and hydrograph separation model to quantify the sources of ground ice near permafrost table in continuous permafrost regions of the central QTP. The results indicated that the ground ice near permafrost table was mainly supplied by active layer water and permafrost water, accounting for 58.9 to 87.0% and 13.0 to 41.1%, respectively, which implying that the active layer was the dominant source. The contribution rates from the active layer to the ground ice in alpine meadow (59 to 69%) was less than that in alpine steppe (70 to 87%). It showed well-developed hydrogeochemical depth gradients, presenting depleted isotopes and positive chemical gradients with depth within the soil layer. The effects of evaporation and freeze-out fractionation on the soil water and ground ice were evident. The results provide additional insights into ground ice sources and cycling near permafrost table in permafrost terrain, and would be helpful for improving process-based detailed hydrologic models under the occurring global warming.

Creep characteristics and process analyses of a thaw slump in the permafrost region of the Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Sun, Zhe; Wang, Yibo; Sun, Yan; Niu, Fujun; Li, Guoyu; Gao, Zeyong

2017-09-01

A thaw slump in the permafrost region of the Qinghai-Tibet Plateau was monitored to investigate typical characteristics of creep positions and processes in combination with soil property analyses. The results show that the thaw settlement exhibits a contraction effect in the horizontal direction because of uneven thaw settlement. Slope displacement of creep occurs only in the top 50 cm of the soil. The gravimetric water content, soil porosity, and soil temperature are higher near the thaw slump in thaw seasons compared with the undisturbed soil; however, the shear strength is lower. Melting ground ice releases thaw water that converges along the slope and forms an overland flow at the front part of the gentle slope area and a ponding depression at the slope bottom. The analyses of slope stability using the infinite slope model shows that the headwall of the slope is inevitably unstable and slides under saturated conditions, whereas the gentle slope area and slope bottom with slight creep displacement are relatively stable. The small retrogressive thaw slump is in an early development stage. With increasing degree of thaw settlement and rate of erosion, the headwall will become steeper and a thermokarst lake will form at the slope bottom.

Flower evolution of alpine forbs in the open top chambers (OTCs) from the Qinghai-Tibet Plateau

PubMed Central

Zhang, Chan; Wang, Lin-Lin; Yang, Yong-Ping; Duan, Yuan-Wen

2015-01-01

Effects of global changes on biodiversity have been paid more and more attention world widely, and the open top chambers (OTCs) are the most common tools to study the effects of climatic warming on plant diversity. However, it remains unclear how flowers evolve under environmental changes, which could help us to understand the changes of plant diversity in the OTCs. We compared the insect diversity and pollen:ovule (P/O) ratio of eight outcrossing species with different life histories inside and outside the OTCs on the Qinghai-Tibet Plateau, to examine the effects induced by OTCs on the evolution of floral traits. In the OTCs, P/O ratio decreased in annuals, but increased in perennials, indicating an overall trend toward selfing in annuals. We found that the insect diversity differed significantly inside and outside the OTCS, with decreases of dipteran insects and bees. We concluded that changes of P/O ratio in the studied plant species might result from pollination failure, which might be the results of mismatch between flowering time and pollinator activities. We also suggested annuals might be in a more extinction risk than perennials in OTCs, if strong inbreeding depression occurs in these annual outcrossing plants. PMID:25998558

[Plant N status in the alpine grassland of the Qinghai-Tibet Plateau: base on the N: P stoichiometry].

PubMed

Zhang, Ren-Yi; Xu, Dang-Hui; Chen, Ling-Yun; Wang, Gang

2014-03-01

Plants from different functional groups show distinct response to nitrogen (N) addition, however, the patterns and underlying mechanisms across the natural N availability gradient remain unexplored. In present studies, effects of soil N fertility on aboveground N pools and production were examined, and the N: P stoichiometry was compared among forbs, graminoids, and legumes on an alpine grassland located in northeast of Qinghai-Tibet Plateau. Mean N: P ratios of the whole community in 2008 and 2009 were 9. 83 and 11.57, respectively, indicating that the sub-alpine grassland was mainly N-limited. The partial redundancy analysis (partial RDA) showed that the biomass percentage of forbs increased, while those of legumes and graminoids decreased with the soil N availability. It suggested that legumes and graminoids were more competitive than forbs in the natural N-limited grassland, which may be due to the N2-fixation ability and high nutrient use efficiency, respectively. Under the projected increasing N deposition, the vegetation tended to shift from graminoids and legumes to forbs. Significant relationships were found between the percentage of legumes biomass and N: P (phosphorus) ratio for the whole community and non-legumes, indicating that legumes could improve the community N status as well as non-legumes N status on the alpine grassland.

Contrasting water use pattern of introduced and native plants in an alpine desert ecosystem, Northeast Qinghai-Tibet Plateau, China.

PubMed

Wu, Huawu; Li, Xiao-Yan; Jiang, Zhiyun; Chen, Huiying; Zhang, Cicheng; Xiao, Xiong

2016-01-15

Plant water use patterns reflect the complex interactions between different functional types and environmental conditions in water-limited ecosystems. However, the mechanisms underlying the water use patterns of plants in the alpine desert of the Qinghai-Tibet Plateau remain poorly understood. This study investigated seasonal variations in the water sources of herbs (Carex moorcroftii, Astragalus adsurgens) and shrubs (Artemisia oxycephala, Hippophae rhamnoides) using stable oxygen-18 isotope methods. The results indicated that the native herbs (C. moorcroftii, A. adsurgens) and one of the shrubs (A. oxycephala) mainly relied on water from the shallow layer (0-30 cm) throughout the growing season, while the introduced shrub (H. rhamnoides) showed plasticity in switching between water from shallow and deep soil layers depending on soil water availability. All studied plants primarily depended on water from shallow soil layers early in the season. The differences of water use patterns between the introduced and native plants are closely linked with the range of active root zones when competing for water. Our findings will facilitate the mechanistic understanding of plant-soil-water relations in alpine desert ecosystems and provide information for screening introduced species for sand fixation. Copyright © 2015 Elsevier B.V. All rights reserved.

Changes in Temperature Sensitivity and Activation Energy of Soil Organic Matter Decomposition in Different Qinghai-Tibet Plateau Grasslands

PubMed Central

Li, Jie; He, Nianpeng; Wei, Xuehong; Gao, Yang; Zuo, Yao

2015-01-01

Qinghai-Tibet Plateau grasslands are unique geographical regions and store substantial soil organic matter (SOM) in the soil surface, which make them very sensitive to global climate change. Here, we focused on three main grassland types (alpine meadow, steppe, and desert) and conducted a soil incubation experiment at five different temperatures (5, 10, 15, 20, and 25°C) to investigate SOM decomposition rates (R), temperature sensitivity (Q 10), and activation energy (E a). The results showed that grassland type and incubation temperature had significant impact on R (P < 0.001), and the values of R were exponential correlated with incubation temperature in three alpine grasslands. At the same temperature, R was in the following order: alpine meadow > alpinesteppe > alpine desert. The Q 10 values differed significantly among different grasslands, and the overall trends were as follows: alpine meadow (1.56 ± 0.09) < alpine steppe (1.88 ± 0.23) < alpine desert (2.39 ± 0.32). Moreover, the E a values differed significantly across different grassland types (P < 0.001) and increased with increasing incubation time. The exponential negative correlations between E a and R at 20°C across all grassland types (all Ps < 0.001) indicated that the substrate-quality temperature hypothesis is applicable to the alpine grasslands. Our findings provide new insights for understanding the responses of SOM decomposition and storage to warming scenarios in this Plateau. PMID:26176705

TMPA Products 3B42RT & 3B42V6: Evaluation and Application in Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Hao, Z.; Sun, L.; Wang, J.

2012-04-01

Hydrological researchers in Qinghai-Tibet Plateau tend to be haunted by deficiency of station gauged precipitation data for the sparse and uneven distribution of local meteorological stations. Fortunately, alternative data can be obtained from TRMM (Tropic Rainfall Measurement Mission) satellite. Preliminary evaluation and necessary correction of TRMM satellite rainfall products is required for the sake of reliability and suitability considering that TRMM precipitation is unconventional and natural condition in Qinghai-Tibet Plateau is unusually complicated. 3B42RT and 3B42V6 products from TRMM Multisatellite Precipitation Analysis(TMPA) are evaluated in northeast Qinghai-Tibet Plateau with 50 stations quality-controlled gauged daily precipitation as the benchmark precipitation set. It is found that the RT data overestimates the actual precipitation greatly while V6 only overestimates it slightly. RT data shows different seasonal and inter-annual accuracies. Summer and autumn see better accuracies than winter and spring and wet years see higher accuracies than dry years. Latitude is believed to be an important factor that influences the accuracy of satellite precipitation. Both RT and V6 can reflect the general pattern of the spatial distribution of precipitation even though RT overestimates the quantity greatly. A new parameter, accumulated precipitation weight point (APWP), was introduced to describe the temporal-spatial pattern evolution of precipitation. The APWP of both RT and V6 were moving from south to north in the past decade, but they are all in the west of station gauged precipitation APWP(s).V6 APWP track fit gauged precipitation perfectly while RT APWP track has over-exaggerated legs, indicating that spatial distribution of RT precipitation experienced unreasonable sharp changes. A practical and operational procedure to correct satellite precipitation data is developed. For RT, there are two steps. Step 1, the downscaling, original daily precipitation was multiplied by a ratio of its monthly satellite/station precipitation gauged precipitation. Step2, objective analysis, Barnes/Cressman successive correction as well as Optimal Interpolation was applied to refine the processed daily results. Step 1 is unnecessary for V6 correction. The accuracy of RT can be improved significantly and the spatial details of satellite precipitation can be obtained as much as possible while quite little improvement showed in V6 correction. Besides, the iteration of successive correction should not be more than twice and the ideal influence radius for Optimal Interpolation is R=5. The original/corrected RT and V6 data sets were used as precipitation inputs to drive a newly developed hydrological model DHM-SP in the headwater region of the Yellow river so as to assess their applicability in simulating the daily runoff. V6 simulation result is qualified even though it is uncorrected. The bias in RT is too much to make use of RT as model input directly while quite satisfied results can be derived from corrected RT input. The simulation results of corrected RT are even better than that of station gauged and V6.

Population Differentiations and Phylogenetic Analysis of Tibet and Qinghai Tibetan Groups Based on 30 InDel Loci.

PubMed

Guo, Yuxin; Shen, Chunmei; Meng, Haotian; Dong, Qian; Kong, Tingting; Yang, Chunhua; Wang, Hongdan; Jin, Rui; Zhu, Bofeng

2016-12-01

In recent years, Insertion/Deletion (InDel) polymorphisms have become a hot area of forensic research. In this study, 30 InDel loci were selected to investigate the genetic polymorphisms of Tibetan groups, which are from Tibet Autonomous Region and Qinghai province of China, and explore the genetic relationships between Tibetan groups and other groups. Allele frequencies of the 30 InDel loci ranged from 0.1219 (HLD111) to 0.5609 (HLD57) in the Tibet Tibetan group and 0.1639 (HLD118) to 0.5655 (HLD124) in the Qinghai Tibetan group. The combined power of discrimination, matching probability, and power of exclusion were 0.999999999986, 0.999999988, and 0.9913 in the Tibet Tibetan group, respectively, and 0.99999999999204, 0.9999999796, and 0.9862 in the Qinghai Tibetan group. The results of principal component analysis, phylogenetic tree, and population structure demonstrated that the four Tibetan groups (Tibetan1, Tibetan2, Tibet, and Qinghai Tibetan groups) clustered together and had relatively close genetic relationships with nine Asian groups and then European and Amerindian groups.

Molecular Biogeography of Tribe Thermopsideae (Leguminosae): A Madrean-Tethyan Disjunction Pattern with an African Origin of Core Genistoides

PubMed Central

Zhang, Ming-Li; Huang, Jian-Feng; Sanderson, Stewart C.; Yan, Ping; Wu, Yu-Hu; Pan, Bo-Rong

2015-01-01

Thermopsideae has 45 species and exhibits a series of interesting biogeographical distribution patterns, such as Madrean-Tethyan disjunction and East Asia-North America disjunction, with a center of endemism in the Qinghai-Xizang Plateau (QTP) and Central Asia. Phylogenetic analysis in this paper employed maximum likelihood using ITS, rps16, psbA-trnH, and trnL-F sequence data; biogeographical approaches included BEAST molecular dating and Bayesian dispersal and vicariance analysis (S-DIVA). The results indicate that the core genistoides most likely originated in Africa during the Eocene to Oligocene, ca. 55-30 Ma, and dispersed eastward to Central Asia at ca. 33.47 Ma. The origin of Thermopsideae is inferred as Central Asian and dated to ca. 28.81 Ma. Ammopiptanthus is revealed to be a relic. Birth of the ancestor of Thermopsideae coincided with shrinkage of the Paratethys Sea at ca. 30 Ma in the Oligocene. The Himalayan motion of QTP uplift of ca. 20 Ma most likely drove the diversification between Central Asia and North America. Divergences in East Asia, Central Asia, the Mediterranean, and so forth, within Eurasia, except for Ammopiptanthus, are shown to be dispersals from the QTP. The onset of adaptive radiation at the center of the tribe, with diversification of most species in Thermopsis and Piptanthus at ca. 4-0.85 Ma in Tibet and adjacent regions, seems to have resulted from intense northern QTP uplift during the latter Miocene to Pleistocene. PMID:26114116

Molecular Biogeography of Tribe Thermopsideae (Leguminosae): A Madrean-Tethyan Disjunction Pattern with an African Origin of Core Genistoides.

PubMed

Zhang, Ming-Li; Huang, Jian-Feng; Sanderson, Stewart C; Yan, Ping; Wu, Yu-Hu; Pan, Bo-Rong

2015-01-01

Thermopsideae has 45 species and exhibits a series of interesting biogeographical distribution patterns, such as Madrean-Tethyan disjunction and East Asia-North America disjunction, with a center of endemism in the Qinghai-Xizang Plateau (QTP) and Central Asia. Phylogenetic analysis in this paper employed maximum likelihood using ITS, rps16, psbA-trnH, and trnL-F sequence data; biogeographical approaches included BEAST molecular dating and Bayesian dispersal and vicariance analysis (S-DIVA). The results indicate that the core genistoides most likely originated in Africa during the Eocene to Oligocene, ca. 55-30 Ma, and dispersed eastward to Central Asia at ca. 33.47 Ma. The origin of Thermopsideae is inferred as Central Asian and dated to ca. 28.81 Ma. Ammopiptanthus is revealed to be a relic. Birth of the ancestor of Thermopsideae coincided with shrinkage of the Paratethys Sea at ca. 30 Ma in the Oligocene. The Himalayan motion of QTP uplift of ca. 20 Ma most likely drove the diversification between Central Asia and North America. Divergences in East Asia, Central Asia, the Mediterranean, and so forth, within Eurasia, except for Ammopiptanthus, are shown to be dispersals from the QTP. The onset of adaptive radiation at the center of the tribe, with diversification of most species in Thermopsis and Piptanthus at ca. 4-0.85 Ma in Tibet and adjacent regions, seems to have resulted from intense northern QTP uplift during the latter Miocene to Pleistocene.

Spatial variability and its main controlling factors of the permafrost soil-moisture on the northern-slope of Bayan Har Mountains in Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Cao, W.; Sheng, Y.

2017-12-01

The soil moisture movement is an important carrier of material cycle and energy flow among the various geo-spheres in the cold regions. It is very critical to protect the alpine ecology and hydrologic cycle in Qinghai-Tibet Plateau. Especially, it becomes one of the key problems to reveal the spatial-temporal variability of soil moisture movement and its main influence factors in earth system science. Thus, this research takes the north slope of Bayan Har Mountains in Qinghai-Tibet Plateau as a case study. The present study firstly investigates the change of permafrost moisture in different slope positions and depths. Based on this investigation, this article attempts to investigate the spatial variability of permafrost moisture and identifies the key influence factors in different terrain conditions. The method of classification and regression tree (CART) is adopted to identify the main controlling factors influencing the soil moisture movement. And the relationships between soil moisture and environmental factors are revealed by the use of the method of canonical correspondence analysis (CCA). The results show that: 1) the change of the soil moisture on the permafrost slope is divided into 4 stages, including the freezing stability phase, the rapid thawing phase, the thawing stability phase and the fast freezing phase; 2) this greatly enhances the horizontal flow in the freezing period due to the terrain slope and the freezing-thawing process. Vertical migration is the mainly form of the soil moisture movement. It leads to that the soil-moisture content in the up-slope is higher than that in the down-slope. On the contrary, the soil-moisture content in the up-slope is lower than that in the down-slope during the melting period; 3) the main environmental factors which affect the slope-permafrost soil-moisture are elevation, soil texture, soil temperature and vegetation coverage. But there are differences in the impact factors of the soil moisture in different freezing-thawing stages; 4) the main factors that affect the slope-permafrost soil-moisture at the shallow depth of 0-20cm are slope, elevation and vegetation coverage. And the main factors influencing the soil moisture at the middle and lower depth are complex.

Impact of naturally leaking carbon dioxide on soil properties and ecosystems in the Qinghai-Tibet plateau

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Xiaohong; Deng, Hongzhang; Wang, Wenke

One of the major concerns for CO 2 capture and storage (CCS) is the potential risk of CO 2 leakage from storage reservoirs on the shallow soil property and vegetation. This study utilizes a naturally occurring CO 2 leaking site in the Qinghai-Tibet Plateau to analog a “leaking CCS site”. Our observations from this site indicates that long-term CO 2 invasion in the vadose zone results in variations of soil properties, such as pH fluctuation, slight drop of total organic carbon, reduction of nitrogen and phosphorus, and concentration changes of soluble ions. Simultaneously, XRD patterns of the soil suggest thatmore » crystallization of soil is enhanced and mineral contents of calcite and anorthite in soil are increased substantially. Parts of the whole ecosystem such as natural wild plants, soil dwelling animals and microorganisms in shallow soil are affected as well. Under a moderate CO 2 concentration (less than 110000 ppm), wild plant growth and development are improved, while an intensive CO2 flux over 112000 ppm causes adverse effects on the plant growth, physiological and biochemical system of plants, and crop quality of wheat. Results of this study provide valuable insight for understanding the possible environmental impacts associated with potential CO 2 leakage into shallow sediments at carbon sequestration sites.« less

Contrasting responses to Pleistocene climate changes: a case study of two sister species Allium cyathophorum and A. spicata (Amaryllidaceae) distributed in the eastern and western Qinghai-Tibet Plateau.

PubMed

Wang, Xinyu; Li, Yuanshuo; Liang, Qianlong; Zhang, Lei; Wang, Qian; Hu, Huan; Sun, Yongshuai

2015-04-01

It has been hypothesized that species occurring in the eastern and the western Qinghai-Tibet Plateau (QTP) responded differently to climate changes during the Pleistocene. Here, we test this hypothesis by phylogeographic analysis of two sister species, Allium cyathophorum and A. spicata. We sequenced two chloroplast DNA (cpDNA) fragments (accD-psaI and the rpl16 intron) of 150 individuals, and the nuclear (ITS) region of 114 individuals, from 19 populations throughout the distributional ranges of these species. The divergence between the two species was dated at 779 - 714 thousand years before the present and was likely initiated by the most major glaciation in the QTP. Analysis of chlorotype diversity showed that A. spicata, the species occurring in the western QTP, contains much lower genetic diversity (0.25) than A. cyathophorum (0.93), which is distributed in the eastern QTP. Moreover, multiple independent tests suggested that the A. spicata population had expanded recently, while no such expansion was detected in A. cyathophorum, indicating a contrasting pattern of responses to Pleistocene climate changes. These findings highlight the importance of geographical topography in determining how species responded to the climate changes that took place in the QTP during the Pleistocene.

Impact of naturally leaking carbon dioxide on soil properties and ecosystems in the Qinghai-Tibet plateau

DOE PAGES

Zhao, Xiaohong; Deng, Hongzhang; Wang, Wenke; ...

2017-06-07

One of the major concerns for CO 2 capture and storage (CCS) is the potential risk of CO 2 leakage from storage reservoirs on the shallow soil property and vegetation. This study utilizes a naturally occurring CO 2 leaking site in the Qinghai-Tibet Plateau to analog a “leaking CCS site”. Our observations from this site indicates that long-term CO 2 invasion in the vadose zone results in variations of soil properties, such as pH fluctuation, slight drop of total organic carbon, reduction of nitrogen and phosphorus, and concentration changes of soluble ions. Simultaneously, XRD patterns of the soil suggest thatmore » crystallization of soil is enhanced and mineral contents of calcite and anorthite in soil are increased substantially. Parts of the whole ecosystem such as natural wild plants, soil dwelling animals and microorganisms in shallow soil are affected as well. Under a moderate CO 2 concentration (less than 110000 ppm), wild plant growth and development are improved, while an intensive CO2 flux over 112000 ppm causes adverse effects on the plant growth, physiological and biochemical system of plants, and crop quality of wheat. Results of this study provide valuable insight for understanding the possible environmental impacts associated with potential CO 2 leakage into shallow sediments at carbon sequestration sites.« less

The developmental trend and influencing factors of aeolian desertification in the Zoige Basin, eastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Hu, Guangyin; Dong, Zhibao; Lu, Junfeng; Yan, Changzhen

2015-12-01

The Zoige Basin is located in the northeastern region of the Qinghai-Tibet Plateau and covers an area of 19,400 km2. At a mean altitude of 3500 m, the basin is highly sensitive to global environmental change and human disturbance due to its high elevation and fragile cold environment. The process of aeolian desertification in the basin can be clearly recognized in Landsat images that show the development of sand sheets and dunes over time. To monitor the spatial and temporal changes of aeolian desertification in the Zoige Basin, we analyzed Landsat images recorded in 1975, 1990, 2000, 2005, and 2010. Results showed that aeolian desertification increased rapidly from 1975 to 1990, was stable from 1990 to 2000, decreased slightly from 2000 to 2005, and decreased sharply from 2005 to 2010. Increasing temperature, overgrazing, rodent damage, and drainage of wetlands were considered the key driving factors of the expansion of aeolian desertification. A number of political measures were initiated in the 1990s to slow desertification, but the countermeasures of grazing prohibition, enclosures, and paving straw checkerboard barriers were not implemented until around 2005. These measures resulted in a dramatic recovery of aeolian desertified land between 2005 and 2010. Based on the cause analysis, anthropogenic factors were identified as the dominant driving force for both development and recovery of aeolian desertified land.

[Traightened on Chinese endemic seed plant species of medicine plants used in Tibetan medicine].

PubMed

Zhou, Hua-rong; Mu, Ze-jing; Du, Xiao-lang; He, Jun-wei; Cao, Lan; Zhong, Guo-yue

2015-09-01

This paper is in order to discussion with the composition and characteristics of Tibetan medicine plant resources, and promote the reasonable protection and utilization of the resources of Tibetan materia medica. Statistical analysis of species, distributions, and others of Chinese endemic seed plant from Tibetan medicine plants and usually used in the clinic of Tibetan medicine. The results showed that there are 523 species (25%) of Chinese endemic seed plant, belonging to 65 families and 162 genera, in about 2 000 varieties of Tibetan medicine plants recorded in relevant literatures. There are 180 Chinese endemic seed plant species (28%) belonging to 42 families and 72 genera from 625 medicine plants usually used in the clinic of Tibetan medicine. Specifically, the most of these Chinese endemic seed plant species are characteristic crude drug used in Tibetan medicine, and mainly or only distributed in Qinghai-Tibet Plateau. And a few species of them were intersected with traditional Chinese medicines (TCM) and other ethnic medicines. In addition, about 10% are listed in China Species Red List. The Qinghai-Tibet Plateau is the most abundant areas of Areal-types of the Chinese endemic seed plant. This is the biological and ecological reason formation the characteristics of Tibetan medicine plant resources. Therefore, strengthen the research of Chinese endemic seed plants used in Tibetan medicine is great significance for the reasonable protection and utilization of Tibetan medicine plant resources.

Genetic evidence for subspecies differentiation of the Himalayan marmot, Marmota himalayana, in the Qinghai-Tibet Plateau

PubMed Central

Lin, Gonghua; Li, Qian; Chen, Jiarui; Qin, Wen; Su, Jianping; Zhang, Tongzuo

2017-01-01

The primary host of plague in the Qinghai-Tibet Plateau (QTP), China, is Marmota himalayana, which plays an essential role in the maintenance, transmission, and prevalence of plague. To achieve a more clear insight into the differentiation of M. himalayana, complete cytochrome b (cyt b) gene and 11 microsatellite loci were analyzed for a total of 423 individuals from 43 localities in the northeast of the QTP. Phylogenetic analyses with maximum likelihood and Bayesian inference methods showed that all derived haplotypes diverged into two primary well-supported monophyletic lineages, I and II, which corresponded to the referential sequences of two recognized subspecies, M. h. himalayana and M. h. robusta, respectively. The divergence between the two lineages was estimated to be at about 1.03 million years ago, nearly synchronously with the divergence between M. baibacina and M. kastschenkoi and much earlier than that between M. vancouverensis and M. caligata. Genetic structure analyses based on the microsatellite dataset detected significant admixture between the two lineages in the mixed region, which verified the intraspecies level of the differentiation between the two lineages. Our results for the first time demonstrated the coexistence of M. h. himalayana and M. h. robusta, and also, determined the distribution range of the two subspecies in the northeast of QTP. We provided fundamental information for more effective plague control in the QTP. PMID:28809943

Role of rainwater induced subsurface flow in water-level dynamics and thermoerosion of shallow thermokarst ponds on the Northeastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Pan, X.; Yu, Q.; You, Y.

2014-12-01

Understanding hydrological and thermal regimes of thermokarst lakes is of great importance for predicting their responses to climate change. However, mechanism of water-level dynamics and associated thermal effects on thermoerosion of thermokarst lakes are still not well understood on the Qinghai-Tibet Plateau (QTP). In this study, we investigate two typical shallow thermokarst ponds (namely small lakes) in a warm permafrost region with thick active layer on the northeastern QTP through quantifying water budget. Results demonstrate that, rainfall induced subsurface lateral flow dominates pond water-level regime. Annual variation of pond water-level relies on areal water budget of surrounding active layer, particularly the high variable of precipitation. Besides, it is worth noting the extraordinary warming during the late ice-cover period, because marked air gap between upper ice-cover and underlying water, led by the upward thawing of thick ice-cover, might result in greenhouse-like condition due to the unique weather that strong solar radiation and little snowpack. This hydrological mechanism also exerts evident impacts on thermal regime and thermoerosion of the shallow thermokarst ponds, and they are closely related to retreat of thermokarst pondshore and underlying permafrost degradation. These findings imply a localized model addressing the unique hydrological and thermal regimes of thermokarst lakes would be essential to study the evolution of these shallow rainwater dominated thermokarst ponds on the QTP.

Surveillance of Echinococcus isolates from Qinghai, China.

PubMed

Ma, Junying; Wang, Hu; Lin, Gonghua; Zhao, Fang; Li, Chao; Zhang, Tongzuo; Ma, Xiao; Zhang, Yongguo; Hou, Zhibin; Cai, Huixia; Liu, Peiyun; Wang, Yongshun

2015-01-15

Echinococcosis is highly endemic over large parts of the Qinghai-Tibet Plateau (QTP), China. Based on a large number of samples, we present data on the current presence, host distribution, and genetic diversity of Echinococcus in the Qinghai Province, located in the northeastern corner of the QTP and constituting >25% of the area of the plateau. We used 521 samples (including 451 newly collected samples and 70 samples from our previous study) from humans, yaks, sheep, goats, dogs, fox, plateau pikas, and voles in 36 counties, and genotyped them using the mitochondrial DNA marker cytochrome oxidase subunit I (cox1) gene and the maximum parsimony and Bayesian reconstruction methods. Based on the 792 bp sequence matrix, we recorded 177 variable sites; 157 were parsimony-informative. A total of 105 haplotypes (H1-H105) were detected, of which H1-H15 and H90-H104, H16-H17, H18-H89, and H105 belonged to Echinococcus shiquicus, Echinococcus multilocularis, Echinococcus granulosus, and Echinococcus canadensis, respectively. Our results showed that, (i) the Qinghai Province was under a high burden of Echinococcus epidemiology; (ii) E. granulosus was the main echinococcosis threat to the local people, and the followed is E. multilocularis; (iii) there are a considerable number of haplotypes shared by domestic animals (sheep, yaks, and dogs) and humans, demonstrating the close relationship between human and domestic animals epidemiology; (iv) the threat of E. shiquicus on humans and livestock can be mostly ignored, while the infection risk of E. canadensis echinococcosis should not be neglected. Copyright © 2014 Elsevier B.V. All rights reserved.

Testing the effect of the Himalayan mountains as a physical barrier to gene flow in Hippophae tibetana Schlect. (Elaeagnaceae)

PubMed Central

Qiong, La; Zhang, Wenju; Wang, Hao; Zeng, Liyan; Birks, H. John B.; Zhong, Yang

2017-01-01

Hippophae tibetana is a small, dioecious wind-pollinated shrub endemic to the Tibetan-Qinghai Plateau. It is one of the shrubs that occur at very high elevations (5250 m a.s.l.). The Himalayan mountains provides a significant geographical barrier to the Qinghai-Tibetan Plateau, dividing the Himalayan area into two regions with Nepal to the south and Tibet to the north. There is no information on how the Himalayan mountains influence gene flow and population differentiation of alpine plants. In this study, we analyzed eight nuclear microsatellite markers and cpDNA trnT-trnF regions to test the role of the Himalayan mountains as a barrier to gene flow between populations of H. tibetana. We also examined the fine-scale genetic structure within a population of H. tibetana on the north slope of Mount (Mt.) Everest. For microsatellite analyses, a total of 241 individuals were sampled from seven populations in our study area (4 from Nepal, 3 from Tibet), including 121 individuals that were spatially mapped within a 100 m × 100 m plot. To test for seed flow, the cpDNA trnT-trnF regions of 100 individuals from 6 populations (4 from Nepal, 2 from Tibet) were also sequenced. Significant genetic differentiation was detected between the two regions by both microsatellite and cpDNA data analyses. These two datasets agree about southern and northern population differentiation, indicating that the Himalayan mountains represent a barrier to H. tibetana limiting gene flow between these two areas. At a fine scale, spatial autocorrelation analysis suggests significant genetic structure within a distance of less than 45 m, which may be attributed mainly to vegetative reproduction and habitat fragmentation, as well as limited gene flow. PMID:28489850

Testing the effect of the Himalayan mountains as a physical barrier to gene flow in Hippophae tibetana Schlect. (Elaeagnaceae).

PubMed

Qiong, La; Zhang, Wenju; Wang, Hao; Zeng, Liyan; Birks, H John B; Zhong, Yang

2017-01-01

Hippophae tibetana is a small, dioecious wind-pollinated shrub endemic to the Tibetan-Qinghai Plateau. It is one of the shrubs that occur at very high elevations (5250 m a.s.l.). The Himalayan mountains provides a significant geographical barrier to the Qinghai-Tibetan Plateau, dividing the Himalayan area into two regions with Nepal to the south and Tibet to the north. There is no information on how the Himalayan mountains influence gene flow and population differentiation of alpine plants. In this study, we analyzed eight nuclear microsatellite markers and cpDNA trnT-trnF regions to test the role of the Himalayan mountains as a barrier to gene flow between populations of H. tibetana. We also examined the fine-scale genetic structure within a population of H. tibetana on the north slope of Mount (Mt.) Everest. For microsatellite analyses, a total of 241 individuals were sampled from seven populations in our study area (4 from Nepal, 3 from Tibet), including 121 individuals that were spatially mapped within a 100 m × 100 m plot. To test for seed flow, the cpDNA trnT-trnF regions of 100 individuals from 6 populations (4 from Nepal, 2 from Tibet) were also sequenced. Significant genetic differentiation was detected between the two regions by both microsatellite and cpDNA data analyses. These two datasets agree about southern and northern population differentiation, indicating that the Himalayan mountains represent a barrier to H. tibetana limiting gene flow between these two areas. At a fine scale, spatial autocorrelation analysis suggests significant genetic structure within a distance of less than 45 m, which may be attributed mainly to vegetative reproduction and habitat fragmentation, as well as limited gene flow.

Soil organic carbon stabilization by iron in permafrost regions of the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Mu, C. C.; Zhang, T. J.; Zhao, Q.; Guo, H.; Zhong, W.; Su, H.; Wu, Q. B.

2016-10-01

A close relationship exists between soil organic carbon (SOC) and reactive iron; however, little is known about the role of iron in SOC preservation in permafrost regions. We determined the amount of SOC associated with reactive iron phases (OC-Fe) in the permafrost regions of the Qinghai-Tibetan Plateau (QTP). The results showed that the percentage of OC-Fe ranged between 0.9% and 59.5% in the upper 30 cm of soil and that the OC-Fe represented 19.5 ± 12.3% of the total SOC pool. No clear vertical distribution pattern in OC-Fe was present in the upper 1 m of soil. Throughout the year, the OC-Fe accounted for relatively stable proportions of the total SOC pool. This study suggests that approximately 20% of SOC is a potential rusty OC pool in the permafrost regions of the QTP. Biogeochemical processes related to the reaction of iron may play important roles in soil carbon cycles in permafrost regions.

Analysis on the Change of Vegetation Coverage in Qinghai Province from 2000 TO 2012

NASA Astrophysics Data System (ADS)

Wang, J.; Yan, Q.; Liu, Z.; Luo, C.

2013-07-01

Qinghai Province is one of the important provinces on the Qinghai-Tibet Plateau in China. Its unique alpine meadow ecosystem makes it become the most concentrated areas of biodiversity in high altitudes in the world. Researching the vegetation coverage and changes of Qinghai province can reflect effectively and timely processing of changes and problems of ecological quality in the region. This research will give a long time series monitoring of the vegetation coverage of Qinghai province based on maximum value composite (MVC) and S-G filtering algorithm using MODIS data of the year of 2000-2012, then analyze the change using coefficient of variability(CV) and trend line analysis. According to research, during the past 13 years, more than half of Qinghai Province's vegetation coverage is well, both the east and south have a high coverage, while the northwest is lower. The changing of vegetation coverage also has showed a steady and improving trend in 13 years. The largest area is slight improved area is about 29.08% of the total area, and the second largest area is significant improved area is about 21.09% of the total area. In this research can learn directly the vegetation coverage and changes of Qinghai province and provide reference and scientific basis for the protection and governance of ecological environment.

Polycyclic aromatic hydrocarbons and organochlorine pesticides in surface soils from the Qinghai-Tibetan plateau.

PubMed

Tao, Shu; Wang, Wentao; Liu, Wenxin; Zuo, Qian; Wang, Xilong; Wang, Rong; Wang, Bin; Shen, Guofeng; Yang, Yuanhe; He, Jin-shen

2011-01-01

Eighty eight surface soil samples were collected from the Qinghai-Tibetan Plateau (QTP) for determination of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethane and metabolites (DDXs) and hexachlorocyclohexane isomers (HCHs). The measured concentrations were 51.8 ± 38.5 ng g(-1), 0.329 ± 0.818 ng g(-1), and 0.467 ± 0.741 ng g(-1) as means and standard deviations of PAHs, DDXs, and HCHs, respectively, which were 1-2 orders of magnitude lower than those reported for eastern China. Significant differences were also revealed among four sub-areas within QTP. PAHs detected in the samples from the remote sub-areas of T'ang-ku-la/Hoh Xil Mountains and along the Qinghai-Tibet highway in the west and northwest of QTP were 1 order of magnitude lower than those from Lhasa and east Qinghai. The differences in soil OCPs among the sub-areas were 2-7 times. Soil PAHs were significantly correlated with emission density and soil organic carbon content (SOC), while OCPs were correlated significantly with the population density and SOC. Based on the calculated backward air mass trajectories and geographical distributions of emission and population, it was revealed that PAHs and OCPs accumulated in the soils in the west and northwest QTP were primarily from long-range transport and may represent the background levels of East Asia. This part of QTP can also serve as an important receptor area for regional or even global long-range transport study. The elevated concentrations of PAHs and OCPs in Lhasa and east Qinghai were mainly from local sources, while PAHs from adjacent Lanzhou area also contributed considerably to the accumulation of PAHs in east Qinghai.

High altitude medicine education in China: exploring a new medical education reform.

PubMed

Luo, Yongjun; Luo, Rong; Li, Weiming; Huang, Jianjun; Zhou, Qiquan; Gao, Yuqi

2012-03-01

China has the largest plateau in the world, which includes the whole of Tibet, part of Qinghai, Xinjiang, Yunnan, and Sichuan. The plateau area is about 257.2×10(4) km(2), which accounts for about 26.8% of the total area of China. According to data collected in 2006, approximately twelve million people were living at high altitudes, between 2200 to 5200 m high, on the Qinghai-Tibetan Plateau. Therefore, there is a need for medical workers who are trained to treat individuals living at high altitudes. To train undergraduates in high altitude medicine, the College of High Altitude Military Medicine was set up at the Third Military Medical University (TMMU) in Chongqing in 1999. This is the only school to teach high altitude medicine in China. Students at TMMU study natural and social sciences, basic medical sciences, clinical medical sciences, and high altitude medicine. In their 5(th) year, students work as interns at the General Hospital of Tibet Military Command in Lhasa for 3 months, where they receive on-site teaching. The method of on-site teaching is an innovative approach for training in high altitude medicine for undergraduates. Three improvements were implemented during the on-site teaching component of the training program: (1) standardization of the learning progress; (2) integration of formal knowledge with clinical experience; and (3) coaching students to develop habits of inquiry and to engage in ongoing self-improvement to set the stage for lifelong learning. Since the establishment of the innovative training methods in 2001, six classes of high altitude medicine undergraduates, who received on-site teaching, have graduated and achieved encouraging results. This evidence shows that on-site teaching needs to be used more widely in high altitude medicine education.

Identification of traffic-related metals and the effects of different environments on their enrichment in roadside soils along the Qinghai-Tibet highway.

PubMed

Zhang, Hua; Wang, Zhaofeng; Zhang, Yili; Ding, Mingjun; Li, Lanhui

2015-07-15

The road transportation could affect roadside soils environment detrimentally, including heavy metal enrichment. In order to identify and evaluate the enrichment of heavy metals resulted from road transportation on the Tibetan Plateau, the 11 heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Rb, Pb and Tl) in the topsoil (0-10 cm depth) from four sites along the Qinghai-Tibet highway were discussed in this study. Our results indicate that heavy metals such as Cr, Cu, Zn, As, Cd and Pb are related to road transportation. The content of most of these heavy metals in roadside soils decreased exponentially with the distance from the road, as did some of the Nemero Synthesis Indexes (PN values). The contamination factor for the traffic-related metals ranged from 0.56 (no pollution) to 5.67 (considerable pollution) and the Nemero Synthesis Indexes of these heavy metals ranged from 0.80 (no pollution) to 4.49 (severe pollution). Cd was of priority concern as it had the highest contamination factor. The highest PN value for these traffic-related heavy metals was found in soils at site TTH (alpine steppe). Although transportation contributed to the high contents of these traffic-related metals in roadside environments, regional differences such as wind and the terrain also had significant relationship with their enrichment in these roadside soils. The roadside distance at which there is a potential risk to livestock and wildlife from the contamination of soils by heavy metals should be determined scientifically along the Qinghai-Tibet highway, based on the different natural environments found in the region. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring coal mine changes and their impact on landscape patterns in an alpine region: a case study of the Muli coal mine in the Qinghai-Tibet Plateau.

PubMed

Qian, Dawen; Yan, Changzhen; Xing, Zanpin; Xiu, Lina

2017-10-14

The Muli coal mine is the largest open-cast coal mine in the Qinghai-Tibet Plateau, and it consists of two independent mining sites named Juhugeng and Jiangcang. It has received much attention due to the ecological problems caused by rapid expansion in recent years. The objective of this paper was to monitor the mining area and its surrounding land cover over the period 1976-2016 utilizing Landsat images, and the network structure of land cover changes was determined to visualize the relationships and pattern of the mining-induced land cover changes. In addition, the responses of the surrounding landscape pattern were analysed by constructing gradient transects. The results show that the mining area was increasing in size, especially after 2000 (increased by 71.68 km 2 ), and this caused shrinkage of the surrounding lands, including alpine meadow wetland (53.44 km 2 ), alpine meadow (6.28 km 2 ) and water (6.24 km 2 ). The network structure of the mining area revealed the changes in lands surrounding the mining area. The impact of mining development on landscape patterns was mainly distributed within a range of 1-6 km. Alpine meadow wetland was most affected in Juhugeng, while alpine meadow was most affected in Jiangcang. The results of this study provide a reference for the ecological assessment and restoration of the Muli coal mine land.

Effects of enhanced UV-B radiation on the diversity and activity of soil microorganism of alpine meadow ecosystem in Qinghai-Tibet Plateau.

PubMed

Niu, Fujun; He, Junxia; Zhang, Gaosen; Liu, Xiaomei; Liu, Wei; Dong, Maoxing; Wu, Fasi; Liu, Yongjun; Ma, Xiaojun; An, Lizhe; Feng, Huyuan

2014-12-01

The effects of enhanced UV-B radiation on abundance, community composition and the total microbial activity of soil bacteria in alpine meadow ecosystem of Qinghai-Tibet Plateau were investigated. Traditional counting and 16S rRNA gene sequencing were used to investigate the culturable bacteria and their composition in soil, meanwhile the total microbial activity was measured by microcalorimetry. The population of soil culturable bacteria was slightly reduced with the enhanced UV-B radiation in both of the two depths, 2.46 × 10(6) CFU/g in upper layer (0-10 cm), 1.44 × 10(6) CFU/g in under layer (10-20 cm), comparing with the control (2.94 × 10(6) CFU/g in upper layer, 1.65 × 10(6) CFU/g in under layer), although the difference was not statistically significant (P > 0.05). However, the bacteria diversity decreased obviously due to enhanced UV-B, the number of species for upper layer was decreased from 20 to 13, and from 16 to 13 for the lower layer. The distribution of species was also quite different between the two layers. Another obvious decrease induced by enhanced UV-B radiation was in the total soil microbial activities, which was represented by the microbial growth rate constant (k) in this study. The results indicated that the culturable bacteria community composition and the total activity of soil microbes have been considerably changed by the enhanced UV-B radiation.

Lower Prevalence of Alzheimer's Disease among Tibetans: Association with Religious and Genetic Factors.

PubMed

Huang, Fukai; Shang, Ying; Luo, Yuandai; Wu, Peng; Huang, Xue; Tan, Xiaohui; Lu, Xingyi; Zhen, Lifang; Hu, Xianda

2016-01-01

The prevalence of dementia differs among racial groups, the highest prevalence being in Latin America (8.5%) compared to sub-Saharan African regions (2-4%). The most common type of dementia is Alzheimer's disease (AD). To estimate the prevalence of AD in the Qinghai-Tibet plateau and to investigate the related factors. This was a cross-sectional, multistage cluster sampling design survey. Data was collected from May 2014 to September 2014 from 4,060 Tibetan aged >60 years. Participants underwent clinical examinations and neuropsychological evaluations. MALDI-TOF was used to test the genotypes of CLU, TFAM, TP53INP1, IGHV1-67, CR1, ApoE, and BIN1. Logistic regression models were used to ascertain the associations with AD. The prevalence of AD among Tibetan individuals aged >60 years was 1.33% (95% CI: 0.98-1.69). The CLU haplotypes AA+GA (odds ratio (OR) = 4.483; 95% CI: 1.069-18.792) of rs2279590 was correlated with AD. The CLU haplotypes GG+GC (OR = 0.184; 95% CI: 0.038-0.888) of rs9331888 and kowtow (OR = 0.203; 95% CI 0.046-0.896) were negatively correlated with AD. A low prevalence of AD was found in Tibetans from the Qinghai-Tibet plateau. Multivariate analysis might suggest that regular "mind-body" religious meditative activities may be negatively associated with AD in this population, as well as the CLU genotype at rs9331888.

Rapid response of arbuscular mycorrhizal fungal communities to short-term fertilization in an alpine grassland on the Qinghai-Tibet Plateau.

PubMed

Xiang, Xingjia; Gibbons, Sean M; He, Jin-Sheng; Wang, Chao; He, Dan; Li, Qian; Ni, Yingying; Chu, Haiyan

2016-01-01

The Qinghai-Tibet Plateau (QTP) is home to the vast grassland in China. The QTP grassland ecosystem has been seriously degraded by human land use practices and climate change. Fertilization is used in this region to increase vegetation yields for grazers. The impact of long-term fertilization on plant and microbial communities has been studied extensively. However, the influence of short-term fertilization on arbuscular mycorrhizal fungal (AMF) communities in the QTP is largely unknown, despite their important functional role in grassland ecosystems. We investigated AMF community responses to three years of N and/or P addition at an experimental field site on the QTP, using the Illumina MiSeq platform (PE 300). Fertilization resulted in a dramatic shift in AMF community composition and NP addition significantly increased AMF species richness and phylogenetic diversity. Aboveground biomass, available phosphorus, and NO3 (-) were significantly correlated with changes in AMF community structure. Changes in these factors were driven by fertilization treatments. Thus, fertilization had a large impact on AMF communities, mediated by changes in aboveground productivity and soil chemistry. Prior work has shown how plants often lower their reliance on AMF symbioses following fertilization, leading to decrease AMF abundance and diversity. However, our study reports a rise in AMF diversity with fertilization treatment. Because AMF can provide stress tolerance to their hosts, we suggest that extreme weather on the QTP may help drive a positive relationship between fertilizer amendment and AMF diversity.

Effects of rodent-induced land degradation on ecosytem carbon fluxes in alpine meadow in the Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Peng, F.; Quangang, Y.; Xue, X.; Guo, J.; Wang, T.

2014-10-01

Land degradation induced by rodent activities is extensively occurred in alpine meadow ecosystem in the Qinghai-Tibet Plateau that would affect the ecosystem carbon (C) balance. We conducted a field experiment with six levels of land degradation (D1-D6, degradation aggravates from D1 to D6) to investigate the effects of land degradation on ecosystem C fluxes. Soil respiration (Rs), net ecosystem exchange (NEE), ecosystem respiration (ER) and gross ecosystem production (GEP) were measured from June to September 2012. Soil respiration, ER, GEP and above-ground biomass (AGB) was significantly higher in slightly degraded (D3 and D6) than in severely degraded land (D1, D2, D4 and D5). Positive averages of NEE in the growing season indicate that alpine meadow ecosystem is a weak C sink during the growing season. Net ecosystem exchange had no significant difference among different degraded levels, but the average NEE in slightly degraded group was 33.6% higher than in severely degraded group. Soil respiration, ER and NEE were positively correlated with AGB whereas soil organic C, labile soil C, total nitrogen (N) and inorganic nitrogen were associated with root biomass (RB). Our results highlight the decline of vegetation C storage of alpine meadow ecosystem with increasing number of rodent holes and suggest the control of AGB on ecosystem C fluxes, and the control of RB on soil C and N with development of land degradation.

The different mechanisms of hypoxic acclimatization and adaptation in Lizard Phrynocephalus vlangalii living on Qinghai-Tibet Plateau.

PubMed

He, Jianzheng; Xiu, Minghui; Tang, Xiaolong; Yue, Feng; Wang, Ningbo; Yang, Shaobin; Chen, Qiang

2013-03-01

Phrynocephalus vlangalii is a species of lizard endemic in China, which lives on Qinghai-Tibet Plateau ranging from 2000 to 4600 m above sea level. In this study, P. vlangalii were collected from low altitude (2750 m) and high altitude (4564 m). The lizards from low altitude were acclimatized in simulated hypoxic chamber (equivalent to 4600 m) for 7, 15, and 30 days. The hematological parameters, heart weight, myocardial capillary density, and myocardial enzyme activities were examined. The results showed that acclimatization to hypoxia significantly increased hemoglobin concentration ([Hb]), hematocrit (Hct), heart weight (HW), heart weight to body mass (HW/BM), lactate dehydrogenase (LDH) activity, but markedly decreased mean corpuscular hemoglobin concentration (MCHC) and succinate dehydrogenase (SDH) activity. Red blood cell (RBC) count, body mass (BM), myocardial capillary density did not change markedly during hypoxic acclimatization. On the other hand, [Hb], Hct, MCHC, HW/BM, myocardium capillary density, and SDH activity of P. vlangalii from high altitude were remarkably higher than those from low-altitude; however, LDH activity of high-altitude P. vlangalii was lower than that of low-altitude lizards. There was no significant difference in HW or BM between populations of high-altitude and low-altitude. Based on the present data, we suggest that P. vlangalii has special anatomical, physiological, and biochemical accommodate mechanisms to live in hypoxic environment, and the regulative mechanisms are different between hypoxic acclimatization and adaptation. Copyright © 2013 Wiley Periodicals, Inc.

Prevalence of refractive errors in Tibetan adolescents.

PubMed

Qian, Xuehan; Liu, Beihong; Wang, Jing; Wei, Nan; Qi, Xiaoli; Li, Xue; Li, Jing; Zhang, Ying; Hua, Ning; Ning, Yuxian; Ding, Gang; Ma, Xu; Wang, Binbin

2018-05-11

The prevalence of adolescent eye disease in remote areas of the Qinghai-Tibet Plateau has rarely been reported. To understand the prevalence of common eye diseases in Tibet, we performed ocular-disease screening on students from primary and secondary schools in Tibet, and compared the prevalence to that in the Central China Plain (referred to here as the "plains area"). The refractive status of students was evaluated with a Spot™ vision screener. The test was conducted three or fewer times for both eyes of each student and results with best correction were recorded. A total of 3246 students from primary and secondary schools in the Tibet Naidong district were screened, yielding a refractive error rate of 28.51%, which was significantly lower than that of the plains group (28.51% vs. 56.92%, p < 0.001). In both groups, the prevalence of refractive errors among females was higher than that among males. We found that Tibetan adolescents had a lower prevalence of refractive errors than did adolescents in the plains area, which may be related to less intensive schooling and greater exposure to sunlight.

Saline Playas on Qinghai-Tibet Plateau as Mars Analog for the Formation-Preservation of Hydrous Salts and Biosignatures

NASA Astrophysics Data System (ADS)

Wang, A.; Zheng, M.; Kong, F.; Sobron, P.; Mayer, D. P.

2010-12-01

Qinghai-Tibet (QT) Plateau has the highest average elevation on Earth (~ 4500 m, about 50-60% of atmospheric pressure at sea-level). The high elevation induces a tremendous diurnal (and seasonal) temperature swing caused by high level of solar irradiation during the day and low level of atmospheric insulation during the evening. In addition, the Himalaya mountain chain (average height >6100 m) in the south of the QT Plateau largely blocks the pathway of humid air from the Indian Ocean, and produces a Hyperarid region (Aridity Index, AI ~ 0.04), the Qaidam Basin (N32-35, E90-100) at the north edge of the QT Plateau. Climatically, the low P, T, large ΔT, high aridity, and high UV radiation all make the Qaidam basin to be one of the most similar places on Earth to Mars. Qaidam basin has the most ancient playas (up to Eocene) and the lakes with the highest salinity on QT Plateau. More importantly, Mg-sulfates appear in the evaporative salts within the most ancient playas (Da Langtang) at the northwest corner of Qaidam basin, which mark the final stage of the evaporation sequence of brines rich in K, Na, Ca, Mg, Fe, C, B, S, and Cl. The evaporation minerals in the saline playas of Qaidam basin, their alteration and preservation under hyperarid conditions can be an interesting analog for the study of Martian salts and salty regolith. We conducted a field investigation at Da Langtan playa in Qaidam basin, with combined remote sensing (ASTER on board of NASA’s Terra satellite, 1.656, 2.167, 2.209, 2.62, 2.336, 2.40 µm), in situ sensing of a portable NIR spectrometer (WIR, 1.25-2.5 µm continuous spectral range), and the laboratory analyses of collected samples from the field (ASD spectrometer, 0.4 -2.5 µm, and Laser Raman spectroscopy). The results indicate that the materials contributing the high albedo layers in playa deposits are carbonate-gypsum-bearing surface soils, salt-clay-bearing exhaumed Pleistocene deposits, dehydrated Na-sulfates, hydrous Mg- & multication-sulfates, carbonates, and chlorites. Halophiles were isolated from the collected evaporative salt samples from Da Langtan. They were cultured on modified growth medium (MGM) under different salinity conditions, and eight strains of halobacteria showed different growth curves. 16S rRNA gene sequences for these eight strains suggested that the halophiles from Da Langtan had high homology with some species of genera of Virgibacillus, Oceanobacillus, Halobacillus, and Ter-ribacillus. In conclusion, the climatic conditions and salt mineralogy within the lacustrine deposits at Da Langtan playa, northwest corner of the Qaidam basin on Qinghai-Tibet Plateau, indicate that this area can be an excellent analog site for studying the precipitation sequence and the subsequent dehydration/degeneration of Martian salts. The finding of hylophyles in this hyperarid environment boosts the importance of exploring salty regolith in future surface explorations to Mars (MSL and ExoMars) in the search for similar biosignatures.

The effects of biotic and abiotic factors on the spatial heterogeneity of alpine grassland vegetation at a small scale on the Qinghai-Tibet Plateau (QTP), China.

PubMed

Wen, Lu; Dong, Shi Kui; Li, Yuan Yuan; Sherman, Ruth; Shi, Jian Jun; Liu, De Mei; Wang, Yan Long; Ma, Yu Shou; Zhu, Lei

2013-10-01

Understanding the complex effects of biotic and abiotic factors on the composition of vegetation is very important for developing and implementing strategies for promoting sustainable grassland development. The vegetation-disturbance-environment relationship was examined in degraded alpine grasslands in the headwater areas of three rivers on the Qinghai-Tibet Plateau in this study. The investigated hypotheses were that (1) the heterogeneity of the vegetation of the alpine grassland is due to a combination of biotic and abiotic factors and that (2) at a small scale, biotic factors are more important for the distribution of alpine vegetation. On this basis, four transects were set along altitudinal gradients from 3,770 to 3,890 m on a sunny slope, and four parallel transects were set along altitudinal gradients on a shady slope in alpine grasslands in Guoluo Prefecture of Qinghai Province, China. It was found that biological disturbances were the major forces driving the spatial heterogeneity of the alpine grassland vegetation and abiotic factors were of secondary importance. Heavy grazing and intensive rat activity resulted in increases in unpalatable and poisonous weeds and decreased fine forages in the form of sedges, forbs, and grasses in the vegetation composition. Habitat degradation associated with biological disturbances significantly affected the spatial variation of the alpine grassland vegetation, i.e., more pioneer plants of poisonous or unpalatable weed species, such as Ligularia virgaurea and Euphorbia fischeriana, were found in bare patches. Environmental/abiotic factors were less important than biological disturbances in affecting the spatial distribution of the alpine grassland vegetation at a small scale. It was concluded that rat control and light grazing should be applied first in implementing restoration strategies. The primary vegetation in lightly grazed and less rat-damaged sites should be regarded as a reference for devising vegetation restoration measures in alpine pastoral regions.

The current municipal solid waste management situation in Tibet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang Jianguo; Lou Zhiying; Ng Silo

The Tibetan Plateau has an average altitude of more than 4,000 m. The total area of Tibetan Plateau is 2,400,000 km{sup 2}, which occupies 25% of the area of China. Due to the high altitude, the environment has low atmospheric pressure, low oxygen content, and low temperature, and is also fragile. Investigations concerning MSW generation and characteristics, MSW management, collection and transportation, and treatment and disposal of MSW covered four representative cities, including the urban areas of Lhasa city, Shigatse, Nedong of Lhoka and Bayi of Nyingtri. The results show that MSW generation in the urban areas of Lhasa citymore » and Tibet were 450 t/d and 3,597 t/d, respectively, in 2006. However, accelerated economic development and flourishing tourism caused by the opening of the Qinghai-Tibet Railway (QTR) have greatly increased solid waste generation to a new high. It is predicted that MSW generation in Tibet will reach 4,026 t/d in 2010 and 4,942 t/d in 2020. MSW management and disposal lag behind MSW generation due to a number of factors such as equipment shortage, insufficient maintenance, exhaustion of waste treatment capacity and low recycling efficiency. Still, MSW in most areas is dumped in the open with no controls. Because no appropriate collection and treatment systems for leachate and landfill gas exist, untreated leachate is discharged directly into the environment, causing serious secondary pollution. Some suggestions on improving the MSW management system are presented in this paper.« less

The current municipal solid waste management situation in Tibet.

PubMed

Jiang, Jianguo; Lou, Zhiying; Ng, Silo; Luobu, Ciren; Ji, Duo

2009-03-01

The Tibetan Plateau has an average altitude of more than 4,000 m. The total area of Tibetan Plateau is 2,400,000 km2, which occupies 25% of the area of China. Due to the high altitude, the environment has low atmospheric pressure, low oxygen content, and low temperature, and is also fragile. Investigations concerning MSW generation and characteristics, MSW management, collection and transportation, and treatment and disposal of MSW covered four representative cities, including the urban areas of Lhasa city, Shigatse, Nedong of Lhoka and Bayi of Nyingtri. The results show that MSW generation in the urban areas of Lhasa city and Tibet were 450 t/d and 3,597 t/d, respectively, in 2006. However, accelerated economic development and flourishing tourism caused by the opening of the Qinghai-Tibet Railway (QTR) have greatly increased solid waste generation to a new high. It is predicted that MSW generation in Tibet will reach 4,026 t/d in 2010 and 4,942 t/d in 2020. MSW management and disposal lag behind MSW generation due to a number of factors such as equipment shortage, insufficient maintenance, exhaustion of waste treatment capacity and low recycling efficiency. Still, MSW in most areas is dumped in the open with no controls. Because no appropriate collection and treatment systems for leachate and landfill gas exist, untreated leachate is discharged directly into the environment, causing serious secondary pollution. Some suggestions on improving the MSW management system are presented in this paper.

Effects of the opening of the Qinghai-Tibet Railway on municipal solid waste management generation in Lhasa.

PubMed

Ding, Xu-Tong; Wang, Ji-Hua

2018-03-01

Lhasa, the capital of Tibet, is located on the Tibetan Plateau. Accelerated economic development and flourishing tourism resulting from the opening of the Qinghai-Tibet Railway (QTR) have increased solid waste generation and contamination in recent years. Using data from Lhasa Statistical Yearbooks and previous studies, this study estimates the future population of permanent residents and tourists using the least squares method to extrapolate the population from 2015-2025, and evaluates the effects of the QTR on municipal solid waste (MSW) generation in Lhasa and estimates future MSW generation. There were approximately 1.35 million tourists in 2008 when the QTR had been operating for 2 years and MSW generation was approximately 470 tons per day. The amount of MSW generated increased dramatically with time after opening the QTR. This study estimates that MSW generation will reach 962 tons per day in 2025. Due to the existence of the QTR, increasing numbers of people are traveling to Lhasa, and tourism has driven the development of the local economy. During the studies, the proportion of MSW produced by tourists increased from 2.99% to 20.06%, and it is estimated that it will increase to 33.49% in 2025. If the current trend continues, Lhasa will face significant challenges from garbage disposal. This study analyzes the current situation of urban garbage treatment in Lhasa, and it suggests several options for improvement to MSW generation, transportation equipment, disposal, and resource recycling.

[Identification of ecological corridors for Tibetan antelope and assessment of their human disturbances in the alpine desert of Qinghai-Tibet Plateau].

PubMed

Zhuge, Hai-jin; Lin, Dan-qi; Li, Xiao-wen

2015-08-01

The alpine desert of Qinghai-Tibet Plateau (QTP) provides the largest habitats for those endangered ungulates (e.g., Tibetan antelope, Tibetan Kiang and wild yak) on the earth. However, human disturbance especially infrastructure constructions (e.g., railway & highway) has increasingly fragmented the habitats of those endangered ungulates by disturbing and interrupting their ecological corridors for their seasonal migration. Aiming at identifying the potential ecological corridors for Tibetan antelope, a GIS-based model-Linkage Mapper was used to model and detect the potential ecological corridors of Tibetan antelope based on the principle of least cost path. Three categories of ecological corridors, i. e., closed (inside reserves), linking (linking the reserves) and open (starting from reserve but ending outside) corridors were distinguished by their spatial interactions with existing major national nature reserves (i.e., Altun, Kekexili and Qiangtang NNRs) in the alpine desert of QTP, and their spatial patterns, conservation status associated with human disturbance were also examined. Although our research indicated a general ecological integration of both habitats and ecological corridors in the alpine desert ecosystem, increasing human disturbance should not be ignored, which particularly partially undermined the functioning of those ecological corridors linking the nature reserves. Considering disadvantages of prevailing separate administrative structure of nature reserve on the effective conservation of ecological corridors for those endangered ungulates, a coordinative conservation network among these major national nature reserves should be established to ensure the unified trans-boundary conservation efforts and to enhance its overall conservation efficacy by sharing information, knowledge and optimizing conservation resources.

Rapid response of arbuscular mycorrhizal fungal communities to short-term fertilization in an alpine grassland on the Qinghai-Tibet Plateau

PubMed Central

Xiang, Xingjia; Gibbons, Sean M.; He, Jin-Sheng; Wang, Chao; He, Dan; Li, Qian; Ni, Yingying

2016-01-01

Background: The Qinghai-Tibet Plateau (QTP) is home to the vast grassland in China. The QTP grassland ecosystem has been seriously degraded by human land use practices and climate change. Fertilization is used in this region to increase vegetation yields for grazers. The impact of long-term fertilization on plant and microbial communities has been studied extensively. However, the influence of short-term fertilization on arbuscular mycorrhizal fungal (AMF) communities in the QTP is largely unknown, despite their important functional role in grassland ecosystems. Methods: We investigated AMF community responses to three years of N and/or P addition at an experimental field site on the QTP, using the Illumina MiSeq platform (PE 300). Results: Fertilization resulted in a dramatic shift in AMF community composition and NP addition significantly increased AMF species richness and phylogenetic diversity. Aboveground biomass, available phosphorus, and NO3− were significantly correlated with changes in AMF community structure. Changes in these factors were driven by fertilization treatments. Thus, fertilization had a large impact on AMF communities, mediated by changes in aboveground productivity and soil chemistry. Discussion: Prior work has shown how plants often lower their reliance on AMF symbioses following fertilization, leading to decrease AMF abundance and diversity. However, our study reports a rise in AMF diversity with fertilization treatment. Because AMF can provide stress tolerance to their hosts, we suggest that extreme weather on the QTP may help drive a positive relationship between fertilizer amendment and AMF diversity. PMID:27478711

Measuring pasture degradation on the Qinghai-Tibet Plateau using hyperspectral dissimilarities and indices

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Bendix, Jörg

2013-10-01

Despite that relevance of pasture degradation on the Qinghai-Tibet Plateau (QTP) is widely postulated, its extent is still unknown. However, livestock grazing is widely accepted as a major factor. This study investigated spectral differences of vegetation patterns along gradients of grazing intensities using plot-based hyperspectral measurements. The measurements were used to define spectral indicators for pasture degradation, which were applied to map asserted proxies for degradation from satellite images. For this purpose, hyperspectral measurements were taken at 11 sites on the north-eastern QTP using a transect design from heavy grazing and therefore asserted degradation near the settlement to less degradation with increasing distance. Potential spectral indicators for degradation were derived from the spectra by calculating the size of continuum removed absorption features and narrow-band indices (NBI). They were compared between degraded and less degraded plots. Linear regressions between proxies and each of the potential spectral indicators were calculated to assess its predictive power. The findings were transferred to larger scales by applying the indicators on two WorldView-2 (WV-2) scenes. Spectral differences between degraded and less degraded plots were obvious regarding a wide range of tested indicators. Several NBIs were considered as good indicators for vegetation cover and species numbers. WV-2 images could be successfully classified into vegetation cover whilst the estimation of species numbers was afflicted with uncertainties. The results demonstrate the potential to estimate degradation proxies using spectrometer measurements and satellite data. Applying these techniques will contribute to a better estimation of spatial degradation patterns on the QTP.

Diploid hybrid origin of Ostryopsis intermedia (Betulaceae) in the Qinghai-Tibet Plateau triggered by Quaternary climate change.

PubMed

Liu, Bingbing; Abbott, Richard J; Lu, Zhiqiang; Tian, Bin; Liu, Jianquan

2014-06-01

Despite the well-known effects that Quaternary climate oscillations had on shaping intraspecific diversity, their role in driving homoploid hybrid speciation is less clear. Here, we examine their importance in the putative homoploid hybrid origin and evolution of Ostryopsis intermedia, a diploid species occurring in the Qinghai-Tibet Plateau (QTP), a biodiversity hotspot. We investigated interspecific relationships between this species and its only other congeners, O. davidiana and O. nobilis, based on four sets of nuclear and chloroplast population genetic data and tested alternative speciation hypotheses. All nuclear data distinguished the three species clearly and supported a close relationship between O. intermedia and the disjunctly distributed O. davidiana. Chloroplast DNA sequence variation identified two tentative lineages, which distinguished O. intermedia from O. davidiana; however, both were present in O. nobilis. Admixture analyses of genetic polymorphisms at 20 SSR loci and sequence variation at 11 nuclear loci and approximate Bayesian computation (ABC) tests supported the hypothesis that O. intermedia originated by homoploid hybrid speciation from O. davidiana and O. nobilis. We further estimated that O. davidiana and O. nobilis diverged 6-11 Ma, while O. intermedia originated 0.5-1.2 Ma when O. davidiana is believed to have migrated southward, contacted and hybridized with O. nobilis possibly during the largest Quaternary glaciation that occurred in this region. Our findings highlight the importance of Quaternary climate change in the QTP in causing hybrid speciation in this important biodiversity hotspot. © 2014 John Wiley & Sons Ltd.

[Ecology suitability study of Chinese materia medica Gentianae Macrophyllae Radix].

PubMed

Lu, You-Yuan; Yang, Yan-Mei; Ma, Xiao-Hui; Zhang, Xiao-Bo; Zhu, Shou-Dong; Jin, Ling

2016-09-01

This paper is aimed to predict ecology suitability distribution of Gentianae Macrophyllae Radix and search the main ecological factors affecting the suitability distribution. The 313 distribution information about G. macrophylla, 186 distribution information about G. straminea, 343 distribution information about G. dauricaand 131 distribution information about G. crasicaulis were collected though investigation and network sharing platform data . The ecology suitable distribution factors for production Gentianae Macrophyllae Radix was analyzed respectively by the software of ArcGIS and MaxEnt with 55 environmental factors. The result of MaxEnt prediction was very well (AUC was above 0.9). The results of predominant factors analysis showed that precipitation and altitude were all the major factors impacting the ecology suitable of Getiana Macrophylla Radix production. G. macrophylla ecology suitable region was mainly concentrated in south of Gansu, Shanxi, central of Shaanxi and east of Qinghai provinces. G. straminea ecology suitable region was mainly concentrated in southwest of Gansu, east of Qinghai, north and northwest of Sichuan, east of Xizang province. G. daurica ecology suitable region was mainly concentrated in south and southwest of Gansu, east of Qinghai, Shanxi and north of Shaanxi province. G. crasicaulis ecology suitable region was mainly concentrated in Sichuan and north of Yunnan, east of Xizang, south of Gansu and east of Qinghai province. The ecological suitability distribution result of Gentianae Macrophyllae Radix was consistent with each species actual distribution. The study could provide reference for the collection and protection of wild resources, meanwhile, provide the basis for the selection of cultivation area of Gentiana Macrophylla Radix. Copyright© by the Chinese Pharmaceutical Association.

Bos grunniens and Bos mutus (Artiodactyla: Bovidae)

USGS Publications Warehouse

Leslie, David M.; Schaller, George B.

2009-01-01

Bos grunniens Linnaeus, 1766, and Bos mutus (Przewalski, 1883) are the domestic and wild forms, respectively, of the bovid commonly called the yak. B. mutus inhabits remote high-elevation alpine meadows and alpine steppe in rolling to mountainous terrain in the Tibetan Plateau, and B. grunniens is maintained widely in China and other parts of Central Asia, and uncommonly elsewhere in the world. Populations of B. mutus are substantially reduced and fragmented throughout its remaining range; the largest numbers occur in northern Tibet and western Qinghai. B. mutus is vulnerable because of poaching and competition with domestic livestock. Although no complete survey of B. mutus has been conducted, there are probably no more than 15,000 remaining in remote areas of the Tibetan Plateau; B. grunniens numbers about 14 million.

The effects of the Qinghai-Tibet railway on heavy metals enrichment in soils.

PubMed

Zhang, Hua; Wang, Zhaofeng; Zhang, Yili; Hu, Zhongjun

2012-11-15

The impact of land transportation on local soil environments is an important topic in environmental and ecological sciences. The rapid development of transportation infrastructure lends increasing importance to studies that identify and evaluate related heavy metal pollution. This paper discusses the effects of railways on soil heavy metal enrichments in the Tibetan plateau. At a representative area along the Haergai-Delingha railway, lead, cadmium, copper, zinc, chromium, nickel, cobalt, and vanadium were measured in 127 topsoil samples (0-10 cm depth). The results indicate that railway transport has a significant effect on the concentration of Zn, Cd and Pb in the soil, with levels of enrichment ranging from no pollution to significant pollution. The affected area was within 20 m of the railway. The soil at Delingha was the most contaminated soil with heavy metals, and the enrichment level of Cd in the soil was the highest along the Qinghai-Tibet railway. The horizontal distributions of the three heavy metals present different characteristics at different sampling sites, which may be due to discrepancies in terrain and vegetation types. Alkaline soils and guardrails along the railway might reduce the effect of soil pollution on local people and animals. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

The Ginghai-Tibet railway and Tibet tourism: travelers' perspectives

Treesearch

Ming Ming Su; Geoffrey Wall

2009-01-01

The Qinghai-Tibet railway opened in July 2006 and boosted Tibetan tourism markedly by increasing the accessibility and affordability of travel from China to Tibet. This study evaluates the railway's impacts on tourists' travel decisions and experiences in Tibet. The relative importance of the train journey in comparison with the destination experience in...

Linking livestock snow disaster mortality and environmental stressors in the Qinghai-Tibetan Plateau: Quantification based on generalized additive models.

PubMed

Li, Yijia; Ye, Tao; Liu, Weihang; Gao, Yu

2018-06-01

Livestock snow disaster occurs widely in Central-to-Eastern Asian temperate and alpine grasslands. The effects of snow disaster on livestock involve a complex interaction between precipitation, vegetation, livestock, and herder communities. Quantifying the relationship among livestock mortality, snow hazard intensity, and seasonal environmental stressors is of great importance for snow disaster early warning, risk assessments, and adaptation strategies. Using a wide-spatial extent, long-time series, and event-based livestock snow disaster dataset, this study quantified those relationships and established a quantitative model of livestock mortality for prediction purpose for the Qinghai-Tibet Plateau region. Estimations using generalized additive models (GAMs) were shown to accurately predict livestock mortality and mortality rate due to snow disaster, with adjusted-R 2 up to 0.794 and 0.666, respectively. These results showed that a longer snow disaster duration, lower temperatures during the disaster, and a drier summer with less vegetation all contribute significantly and non-linearly to higher mortality (rate), after controlling for elevation and socioeconomic conditions. These results can be readily applied to risk assessment and risk-based adaptation actions. Copyright © 2017 Elsevier B.V. All rights reserved.

Large-scale estimates of gross primary production on the Qinghai-Tibet plateau based on remote sensing data

NASA Astrophysics Data System (ADS)

Ma, M., II; Yuan, W.; Dong, J.; Zhang, F.; Cai, W.; Li, H.

2017-12-01

Vegetation gross primary production (GPP) is an important variable for the carbon cycle on the Qinghai-Tibetan Plateau (QTP). Based on the measurements from twelve eddy covariance (EC) sites, we validated a light use efficiency model (i.e. EC-LUE) to evaluate the spatial-temporal patterns of GPP and the effect of environmental variables on QTP. The EC-LUE model explained 85.4% of the daily observed GPP variations through all of the twelve EC sites, and characterized very well the seasonal changes of GPP. Annual GPP over the entire QTP ranged from 575 to 703 Tg C, and showed a significantly increasing trend from 1982 to 2013. However, there were large spatial heterogeneities in long-term trends of GPP. Throughout the entire QTP, air temperature TA increase had a greater influence than solar radiation and PREC changes on productivity. Moreover, our results highlight the large uncertainties of previous GPP estimates due to insufficient parameterization and validations. When compared with GPP estimates of the EC-LUE model, most Coupled Model Intercomparison Project (CMIP5) GPP products overestimate the magnitude and increasing trends of regional GPP, which potentially impact the feedback of ecosystems to regional climate changes.

Eco-Environment Status Evaluation and Change Analysis of Qinghai Based on National Geographic Conditions Census Data

NASA Astrophysics Data System (ADS)

Zheng, M.; Zhu, M.; Wang, Y.; Xu, C.; Yang, H.

2018-04-01

As the headstream of the Yellow River, the Yangtze River and the Lantsang River, located in the hinterland of Qinghai-Tibet Plateau, Qinghai province is hugely significant for ecosystem as well as for ecological security and sustainable development in China. With the accomplishment of the first national geographic condition census, the frequent monitoring has begun. The classification indicators of the census and monitoring data are highly correlated with Technical Criterion for Ecosystem Status Evaluation released by Ministry of Environmental Protection in 2015. Based on three years' geographic conditions data (2014-2016), Landsat-8 images and thematic data (water resource, pollution emissions, meteorological data, soil erosion, etc.), a multi-years and high-precision eco-environment status evaluation and spatiotemporal change analysis of Qinghai province has been researched on the basis of Technical Criterion for Ecosystem Status Evaluation in this paper. Unlike the evaluation implemented by environmental protection department, the evaluation unit in this paper is town rather than county. The evaluation result shows that the eco-environment status in Qinghai is generally in a fine condition, and has significant regional differences. The eco-environment status evaluation based on national geographic conditions census and monitoring data can improve both the time and space precision. The eco-environment status with high space precise and multi-indices is a key basis for environment protection decision-making.

Mechanisms control the soil organic carbon loss with grassland degradation in the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Peng, Fei; Xian, Xue; You, Quangang; Huang, Cuihua; Dong, Siyang; Liao, Jie; Duan, Hanchen; Wang, Tao

2017-04-01

Grassland in the Qinghai-Tibet Plateau (QTP) provides tremendous carbon (C) sinks and is the important ground for grazing. Grassland degradation, the loss of plant coverage and the emergence of sand activities, results in substantial reduction in soil organic carbon (SOC). To demonstrate the specific degradation pattern of SOC and elucidate underlying mechanisms, a sequence of five degradation stages over the whole grassland in the QTP were investigated. The survey and laboratory data were analyzed by three structural equation modeling (SEM) analysis. One of the analysis focused on the biological processes while the other two included both the biological and physical processes. Soil temperature had no significant change but soil moisture decreased in all layers. The above and the below-ground plant production decreased and the dominant plant functional group shifted from sedge and grass to forbs. The SOC concentration declined about 40-50% in the very severely degraded comparing with intact alpine grassland.All the three models were successfully fitted with R2 about 0.50. Three biological processes can explain the SOC change. The decrease in soil moisture suppressed C output through soil respiration (Rs) thus lower the SOC loss with land degradation. Decline in the plant production due to a decrease in coverage or to the change in relative abundance of sedge, forbs and grass directly or indirectly reduce the C input and finally lead to the 40-50% loss in SOC. The significant pathways from soil microclimate and soil properties to SOC in the black box model, only one significant pathway from soil properties to SOC indicate that physical processes like the wind and water erosion might control the SOC loss with land degradation in the alpine grassland in the QTP.

Belowground carbon responses to experimental warming regulated by soil moisture change in an alpine ecosystem of the Qinghai-Tibet Plateau.

PubMed

Xue, Xian; Peng, Fei; You, Quangang; Xu, Manhou; Dong, Siyang

2015-09-01

Recent studies found that the largest uncertainties in the response of the terrestrial carbon cycle to climate change might come from changes in soil moisture under the elevation of temperature. Warming-induced change in soil moisture and its level of influence on terrestrial ecosystems are mostly determined by climate, soil, and vegetation type and their sensitivity to temperature and moisture. Here, we present the results from a warming experiment of an alpine ecosystem conducted in the permafrost region of the Qinghai-Tibet Plateau using infrared heaters. Our results show that 3 years of warming treatments significantly elevated soil temperature at 0-100 cm depth, decreased soil moisture at 10 cm depth, and increased soil moisture at 40-100 cm depth. In contrast to the findings of previous research, experimental warming did not significantly affect NH 4 (+)-N, NO 3 (-)-N, and heterotrophic respiration, but stimulated the growth of plants and significantly increased root biomass at 30-50 cm depth. This led to increased soil organic carbon, total nitrogen, and liable carbon at 30-50 cm depth, and increased autotrophic respiration of plants. Analysis shows that experimental warming influenced deeper root production via redistributed soil moisture, which favors the accumulation of belowground carbon, but did not significantly affected the decomposition of soil organic carbon. Our findings suggest that future climate change studies need to take greater consideration of changes in the hydrological cycle and the local ecosystem characteristics. The results of our study will aid in understanding the response of terrestrial ecosystems to climate change and provide the regional case for global ecosystem models.

Phylogeny and biogeography of Primula sect. Armerina: implications for plant evolution under climate change and the uplift of the Qinghai-Tibet Plateau.

PubMed

Ren, Guangpeng; Conti, Elena; Salamin, Nicolas

2015-08-16

The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section. We sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns. Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic patterns.

Phylogeographic study of Chinese seabuckthorn (Hippophae rhamnoides subsp. sinensis Rousi) reveals two distinct haplotype groups and multiple microrefugia on the Qinghai-Tibet Plateau

PubMed Central

Wang, Hongfang; Liu, Han; Yang, Mingbo; Bao, Lei; Ge, Jianping

2014-01-01

Historical climate change can shape the genetic pattern of a species. Studies on this phenomenon provide great advantage in predicting the response of species to current and future global climate change. Chinese seabuckthorn (Hippophae rhamnoides subsp. sinensis) is one of the most important cultivated plants in Northwest China. However, the subspecies history and the potential genetic resources within the subspecies range remain unclear. In this study, we utilized two intergenic chloroplast regions to characterize the spatial genetic distribution of the species. We found 19 haplotypes in total, 12 of which were unique to the Chinese seabuckthorn. The populations observed on the Qinghai-Tibet Plateau (QTP) consisted of most of the haplotypes, while in the northeast of the range of the subspecies, an area not on the QTP, only four haplotypes were detected. Our study also revealed two distinct haplotype groups of the subspecies with a sharp transition region located in the south of the Zoige Basin. 89.96% of the genetic variation located between the regions. Mismatch analysis indicated old expansions of these two haplotype groups, approximately around the early stage of Pleistocene. Additional morphological proofs from existing studies and habitat differentiation supported a long independent colonization history among the two regions. Potential adaptation probably occurred but needs more genome and morphology data in future. Chinese seabuckthorn have an older population expansion compared with subspecies in Europe. The lack of large land ice sheets and the heterogeneous landscape of the QTP could have provided extensive microrefugia for Chinese seabuckthorn during the glaciation period. Multiple localities sustaining high-frequency private haplotypes support this hypothesis. Our study gives clear insight into the distribution of genetic resources and the evolutionary history of Chinese seabuckthorn. PMID:25540697

Range-Wide Snow Leopard Phylogeography Supports Three Subspecies.

PubMed

Janecka, Jan E; Zhang, Yuguang; Li, Diqiang; Munkhtsog, Bariushaa; Bayaraa, Munkhtsog; Galsandorj, Naranbaatar; Wangchuk, Tshewang R; Karmacharya, Dibesh; Li, Juan; Lu, Zhi; Uulu, Kubanychbek Zhumabai; Gaur, Ajay; Kumar, Satish; Kumar, Kesav; Hussain, Shafqat; Muhammad, Ghulam; Jevit, Matthew; Hacker, Charlotte; Burger, Pamela; Wultsch, Claudia; Janecka, Mary J; Helgen, Kristofer; Murphy, William J; Jackson, Rodney

2017-09-01

The snow leopard, Panthera uncia, is an elusive high-altitude specialist that inhabits vast, inaccessible habitat across Asia. We conducted the first range-wide genetic assessment of snow leopards based on noninvasive scat surveys. Thirty-three microsatellites were genotyped and a total of 683 bp of mitochondrial DNA sequenced in 70 individuals. Snow leopards exhibited low genetic diversity at microsatellites (AN = 5.8, HO = 0.433, HE = 0.568), virtually no mtDNA variation, and underwent a bottleneck in the Holocene (∼8000 years ago) coinciding with increased temperatures, precipitation, and upward treeline shift in the Tibetan Plateau. Multiple analyses supported 3 primary genetic clusters: (1) Northern (the Altai region), (2) Central (core Himalaya and Tibetan Plateau), and (3) Western (Tian Shan, Pamir, trans-Himalaya regions). Accordingly, we recognize 3 subspecies, Panthera uncia irbis (Northern group), Panthera uncia uncia (Western group), and Panthera uncia uncioides (Central group) based upon genetic distinctness, low levels of admixture, unambiguous population assignment, and geographic separation. The patterns of variation were consistent with desert-basin "barrier effects" of the Gobi isolating the northern subspecies (Mongolia), and the trans-Himalaya dividing the central (Qinghai, Tibet, Bhutan, and Nepal) and western subspecies (India, Pakistan, Tajikistan, and Kyrgyzstan). Hierarchical Bayesian clustering analysis revealed additional subdivision into a minimum of 6 proposed management units: western Mongolia, southern Mongolia, Tian Shan, Pamir-Himalaya, Tibet-Himalaya, and Qinghai, with spatial autocorrelation suggesting potential connectivity by dispersing individuals up to ∼400 km. We provide a foundation for global conservation of snow leopard subspecies, and set the stage for in-depth landscape genetics and genomic studies. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The characteristics changes of pH and EC of atmospheric precipitation and analysis on the source of acid rain in the source area of the Yangtze River from 2010 to 2015

NASA Astrophysics Data System (ADS)

Zong-Jie, Li; Song, Ling-Ling; Jing-zhu, Ma; Li, Yong-ge

2017-05-01

Through the analysis of pH value, EC, precipitation and wind speed of 402 precipitation samples in the source region of the Yangtze River from January 1, 2010 to December 31, 2015, especially for the analysis of the 14 acid rain events. The results showed that: the acid rain in the source region of the Yangtze River was mainly affected by the southwest monsoon and the westerly circulation. The occurrence of acid rain mainly controlled by industrial pollution and other pollutants coming from India and other surrounding areas. And the other cause was that because of the Qinghai Tibet highway and the Qinghai Tibet railway, there were a lot of cars coming and going. And there were people in the summer to plateau tourism increased year by year, and more for self-driving travelling. This added additional pollutants (automobile exhaust) for the source of the Yangtze River. During the period of sampling, the variation range of pH value was from 4.0 to 8.57, with the mean was 6.37. And the range of EC was from 5.2 to 124.4 μs/cm, the average was 27.59 μs/cm. The order of conductivity in the four seasons was Spring > Winter > Summer > Autumn. And the order of pH in four seasons was Summer > Spring = Winter > Autumn. The results are also helpful for further understanding the acid rain in the Tibetan Plateau and providing scientific basis for the effective prevention and control of acid rain.

Tracers Show Ecohydrologic Influences on Runoff Generation Components at the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Liu, H.; Liu, J.; Peng, A.; Gu, W.; Wang, W.; Gao, F.

2017-12-01

In order to learn more about the critical zone ecohydrological dynamics at the Qinghai-Tibet Plateau, a research on the identification of runoff components using tracers was carried out in the Niyang River upstream, a tributary of the Yalung Zangbo River. In this study, four basins with the areas of 182, 216, 243, 213 km2 which are embed in a larger basin were sampled at altitudes between 3667 to 6140 m. The types of land use in the basins mainly include forest land, grassland and glacier. River water and precipitation were sampled monthly, while spring water, glacial ice, soil, and plants were sampled seasonally. Soil and plant samples were taken along the valleys with spatial interval of about 5 km. Soil and plant waters were extracted via cryogenic vacuum distillation method, and then analyzed for isotopes and ions. Preliminary results show that the δD and δ18O of the precipitation water spread approximately along the LMWL of the Namucuo Lake near Lasa city, which varied according to altitude. Stem water δD and δ18O from different elevations and tree species also varied regularly, albeit with no apparent relationship to recent precipitation. It appears that trees utilized fissure water and soil water formed by precipitation. Future efforts will involve (1) an expanded sampling strategy across basins, and (2) a series of experiments on the Hydrohill catchment in the Chuzhou Experimental Facility, whereby an improved understanding of K+, Na+, Ca2+ and Mg2+ export dynamics could aid in much better description and modeling of Niyang River runoff composition and generation. This research is funded by the NSFC project 91647111 and 91647203, which are included in the Runoff Change and its Adaptive Management in the Major Rivers in Southwestern China Major Research Plan.

Pore Effect on the Occurrence and Formation of Gas Hydrate in Permafrost of Qilian Mountain, Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Gao, H.; Lu, H.; Lu, Z.

2014-12-01

Gas hydrates were found in the permafrost of Qilian Mountain, Qinghai- Tibet Plateau, China in 2008. It has been found that gas hydrates occur in Jurassic sedimentary rocks, and the hydrated gases are mainly thermogenic. Different from the gas hydrates existing in loose sands in Mallik, Mackenzie Delta, Canada and North Slope, Alaska, USA, the gas hydrates in Qilian Mountain occurred in hard rocks. For understanding the occurrence and formation mechanism of gas hydrate in hard rcok, extensive experimental investigations have been conducted to study the pore features and hydrate formation in the rocks recovered from the hydrate layers in Qilian Mountain. The structures of sedimentary rock were observed by high-resolution X-ray CT, and pore size distribution of a rock specimen was measured with the mercury-injection method. Methane hydrate was synthesized in water-saturated rocks, and the saturations of hydrate in sedimentary rocks of various types were estimated from the amount of gas released from certain volume of rock. X-ray CT observation revealed that fractures were developed in the rocks associated with faults, while those away from faults were generally with massive structure. The mercury-injection analysis of pore features found that the porosities of the hydrate-existing rocks were generally less than 3%, and the pore sizes were generally smaller than 100 nm. The synthesizing experiments found that the saturation of methane hydrate were generally lower than 6% of pore space in rocks, but up to 16% when fractures developed. The low hydrate saturation in Qilian sedimentary rocks has been found mainly due to the small pore size of rock. The low hydrate saturation in the rocks might be the reason for the failure of regional seismic and logging detections of gas hydrates in Qilian Mountain.

Spatiotemporal distribution and the characteristics of the air temperature of a river source region of the Qinghai-Tibet Plateau.

PubMed

Deng, Cai; Zhang, Wanchang

2018-05-30

As the backland of the Qinghai-Tibet Plateau, the river source region is highly sensitive to changes in global climate. Air temperature estimation using remote sensing satellite provides a new way of conducting studies in the field of climate change study. A geographically weighted regression model was applied to estimate synchronic air temperature from 2001 to 2015 using Moderate-Resolution Imaging Spectroradiometry (MODIS) data. The results were R 2  = 0.913 and RMSE = 2.47 °C, which confirmed the feasibility of the estimation. The spatial distribution and variation characteristics of the average annual and seasonal air temperature were analyzed. The findings are as follows: (1) the distribution of average annual air temperature has significant terrain characteristics. The reduction in average annual air temperature along the elevation of the region is 0.19 °C/km, whereas the reduction in the average annual air temperature along the latitude is 0.04 °C/degree. (2) The average annual air temperature increase in the region is 0.37 °C/decade. The average air temperature increase could be arranged in the following decreasing order: Yangtze River Basin > Mekong River Basin > Nujiang River Basin > Yarlung Zangbo River Basin > Yellow River Basin. The fastest, namely, Yangtze River Basin, is 0.47 °C/decade. (3) The average air temperature rise in spring, summer, and winter generally increases with higher altitude. The average annual air temperature in different types of lands following a decreasing order is as follows: wetland > construction land > bare land glacier > shrub grassland > arable land > forest land > water body and that of the fastest one, wetland, is 0.13 °C/year.

Insights into the evolution of pathogenicity of Escherichia coli from genomic analysis of intestinal E. coli of Marmota himalayana in Qinghai-Tibet plateau of China.

PubMed

Lu, Shan; Jin, Dong; Wu, Shusheng; Yang, Jing; Lan, Ruiting; Bai, Xiangning; Liu, Sha; Meng, Qiong; Yuan, Xuejiao; Zhou, Juan; Pu, Ji; Chen, Qiang; Dai, Hang; Hu, Yuanyuan; Xiong, Yanwen; Ye, Changyun; Xu, Jianguo

2016-12-07

Escherichia coli is both of a widespread harmless gut commensal and a versatile pathogen of humans. Domestic animals are a well-known reservoir for pathogenic E. coli. However, studies of E. coli populations from wild animals that have been separated from human activities had been very limited. Here we obtained 580 isolates from intestinal contents of 116 wild Marmot Marmota himalayana from Qinghai-Tibet plateau, China, with five isolates per animal. We selected 125 (hereinafter referred to as strains) from the 580 isolates for genome sequencing, based on unique pulse field gel electrophoresis patterns and at least one isolate per animal. Whole genome sequence analysis revealed that all 125 strains carried at least one and the majority (79.2%) carried multiple virulence genes based on the analysis of 22 selected virulence genes. In particular, the majority of the strains carried virulence genes from different pathovars as potential 'hybrid pathogens'. The alleles of eight virulence genes from the Marmot E. coli were found to have diverged earlier than all known alleles from human and other animal E. coli. Phylogenetic analysis of the 125 Marmot E. coli genomes and 355 genomes selected from 1622 human and other E. coli strains identified two new phylogroups, G and H, both of which diverged earlier than the other phylogroups. Eight of the 12 well-known pathogenic E. coli lineages were found to share a most recent common ancestor with one or more Marmot E. coli strains. Our results suggested that the intestinal E. coli of the Marmots contained a diverse virulence gene pool and is potentially pathogenic to humans. These findings provided a new understanding of the evolutionary origin of pathogenic E. coli.

Species delimitation in plants using the Qinghai-Tibet Plateau endemic Orinus (Poaceae: Tridentinae) as an example.

PubMed

Su, Xu; Wu, Guili; Li, Lili; Liu, Jianquan

2015-07-01

Accurate identification of species is essential for the majority of biological studies. However, defining species objectively and consistently remains a challenge, especially for plants distributed in remote regions where there is often a lack of sufficient previous specimens. In this study, multiple approaches and lines of evidence were used to determine species boundaries for plants occurring in the Qinghai-Tibet Plateau, using the genus Orinus (Poaceae) as a model system for an integrative approach to delimiting species. A total of 786 individuals from 102 populations of six previously recognized species were collected for niche, morphological and genetic analyses. Three plastid DNA regions (matK, rbcL and trnH-psbA) and one nuclear DNA region [internal transcribed space (ITS)] were sequenced. Whereas six species had been previously recognized, statistical analyses based on character variation, molecular data and niche differentiation identified only two well-delimited clusters, together with a third possibly originating from relatively recent hybridization between, or historical introgression from, the other two. Based on a principle of integrative species delimitation to reconcile different sources of data, the results provide compelling evidence that the six previously recognized species of the genus Orinus that were examined should be reduced to two, with new circumscriptions, and a third, identified in this study, should be described as a new species. This empirical study highlights the value of applying genetic differentiation, morphometric statistics and ecological niche modelling in an integrative approach to re-circumscribing species boundaries. The results produce relatively objective, operational and unbiased taxonomic classifications of plants occurring in remote regions. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Relative Roles of Deterministic and Stochastic Processes in Driving the Vertical Distribution of Bacterial Communities in a Permafrost Core from the Qinghai-Tibet Plateau, China.

PubMed

Hu, Weigang; Zhang, Qi; Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; Stegen, James C; An, Lizhe; Feng, Huyuan

2015-01-01

Understanding the processes that influence the structure of biotic communities is one of the major ecological topics, and both stochastic and deterministic processes are expected to be at work simultaneously in most communities. Here, we investigated the vertical distribution patterns of bacterial communities in a 10-m-long soil core taken within permafrost of the Qinghai-Tibet Plateau. To get a better understanding of the forces that govern these patterns, we examined the diversity and structure of bacterial communities, and the change in community composition along the vertical distance (spatial turnover) from both taxonomic and phylogenetic perspectives. Measures of taxonomic and phylogenetic beta diversity revealed that bacterial community composition changed continuously along the soil core, and showed a vertical distance-decay relationship. Multiple stepwise regression analysis suggested that bacterial alpha diversity and phylogenetic structure were strongly correlated with soil conductivity and pH but weakly correlated with depth. There was evidence that deterministic and stochastic processes collectively drived bacterial vertically-structured pattern. Bacterial communities in five soil horizons (two originated from the active layer and three from permafrost) of the permafrost core were phylogenetically random, indicator of stochastic processes. However, we found a stronger effect of deterministic processes related to soil pH, conductivity, and organic carbon content that were structuring the bacterial communities. We therefore conclude that the vertical distribution of bacterial communities was governed primarily by deterministic ecological selection, although stochastic processes were also at work. Furthermore, the strong impact of environmental conditions (for example, soil physicochemical parameters and seasonal freeze-thaw cycles) on these communities underlines the sensitivity of permafrost microorganisms to climate change and potentially subsequent permafrost thaw.

Relative Roles of Deterministic and Stochastic Processes in Driving the Vertical Distribution of Bacterial Communities in a Permafrost Core from the Qinghai-Tibet Plateau, China

PubMed Central

Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; Stegen, James C.; An, Lizhe; Feng, Huyuan

2015-01-01

Understanding the processes that influence the structure of biotic communities is one of the major ecological topics, and both stochastic and deterministic processes are expected to be at work simultaneously in most communities. Here, we investigated the vertical distribution patterns of bacterial communities in a 10-m-long soil core taken within permafrost of the Qinghai-Tibet Plateau. To get a better understanding of the forces that govern these patterns, we examined the diversity and structure of bacterial communities, and the change in community composition along the vertical distance (spatial turnover) from both taxonomic and phylogenetic perspectives. Measures of taxonomic and phylogenetic beta diversity revealed that bacterial community composition changed continuously along the soil core, and showed a vertical distance-decay relationship. Multiple stepwise regression analysis suggested that bacterial alpha diversity and phylogenetic structure were strongly correlated with soil conductivity and pH but weakly correlated with depth. There was evidence that deterministic and stochastic processes collectively drived bacterial vertically-structured pattern. Bacterial communities in five soil horizons (two originated from the active layer and three from permafrost) of the permafrost core were phylogenetically random, indicator of stochastic processes. However, we found a stronger effect of deterministic processes related to soil pH, conductivity, and organic carbon content that were structuring the bacterial communities. We therefore conclude that the vertical distribution of bacterial communities was governed primarily by deterministic ecological selection, although stochastic processes were also at work. Furthermore, the strong impact of environmental conditions (for example, soil physicochemical parameters and seasonal freeze-thaw cycles) on these communities underlines the sensitivity of permafrost microorganisms to climate change and potentially subsequent permafrost thaw. PMID:26699734

Atmospheric oxalic acid and related secondary organic aerosols in Qinghai Lake, a continental background site in Tibet Plateau

NASA Astrophysics Data System (ADS)

Meng, Jingjing; Wang, Gehui; Li, Jianjun; Cheng, Chunlei; Cao, Junji

2013-11-01

Summertime PM2.5 aerosols collected from Qinghai Lake (3200 m a.s.l.), a remote continental site in the northeastern part of Tibetan Plateau, were analyzed for dicarboxylic acids (C2-C11), ketocarboxylic acids and α-dicarbonyals. Oxalic acid (C2) is the dominant dicarboxylic acid in the samples, followed by malonic, succinic and azelaic acids. Total dicarboxylic acids (231 ± 119 ng m-3), ketocarboxylic acids (8.4 ± 4.3 ng m-3), and α-dicarbonyls (2.7 ± 2.1 ng m-3) at the Tibetan background site are 2-5 times less than those detected in lowland areas such as 14 Chinese megacities. Compared to those in other urban and marine areas enhancements in relative abundances of C2/total diacids and diacids-C/WSOC of the PM2.5 samples suggest that organic aerosols in the region are more oxidized due to strong solar radiation. Molecular compositions and air mass trajectories demonstrate that the above secondary organic aerosols in the Qinghai Lake atmosphere are largely derived from long-range transport. Ratios of oxalic acid, glyoxal and methylglyoxal to levoglucosan in PM2.5 aerosols emitted from household burning of yak dung, a major energy source for Tibetan in the region, are 30-400 times lower than those in the ambient air, which further indicates that primary emission from biomass burning is a negligible source of atmospheric oxalic acid and α-dicarbonyls at this background site.

Temporal trend and sources of speciated atmospheric mercury at Waliguan GAW station, northwestern China

NASA Astrophysics Data System (ADS)

Fu, X. W.; Feng, X.; Liang, P.; Deli-Geer; Zhang, H.; Ji, J.; Liu, P.

2011-11-01

Measurements of speciated atmospheric mercury were conducted at a remote mountain-top station (WLG) at the edge of northeastern part of the Qinghai-Xizang Plateau, western China. Mean concentrations of total gaseous mercury (TGM), particulate mercury (PHg), and reactive gaseous mercury (RGM) during the whole sampling campaign were 1.98 ± 0.98 ng m-3, 19.4 ± 18.1 pg m-3, and 7.4 ± 4.8 pg m-3, respectively. Levels of speciated Hg at WLG were slightly higher than those reported from remote areas of North America and Europe. Both regional emissions and long-rang transport played a remarkable role in the distribution of TGM and PHg in ambient air at WLG, whereas RGM showed major links to the regional sources, likely as well as the in-situ productions by photochemical processes. Regional sources for speciated Hg were mostly located to the east of WLG, which is the most developed areas of Qinghai province and accounted for most of the province's anthropogenic Hg emissions. Potential source contribution function (PSCF) results showed a strong impact of long-range transport from eastern Gansu, western Ningxia and Shanxi Province, with good accordance with locations of urban areas and industrial centers. Moreover, we found that northern India was also an important source region of WLG during the sampling campaign, and this is the first time of direct evidence of long-range transport of atmospheric Hg from India to northeastern Tibetan Plateau. Seasonal and diurnal variations of TGM were in contrast with most of the previous studies in China, with relatively higher levels in warm seasons and night, respectively. The temporal trend of TGM also highlighted the impact of long-range transport on the distribution of TGM in ambient air at WLG.

Influences of climate change on area variation of Qinghai Lake on Qinghai-Tibetan Plateau since 1980s.

PubMed

Tang, Lingyi; Duan, Xiaofang; Kong, Fanjin; Zhang, Fan; Zheng, Yangfan; Li, Zhen; Mei, Yi; Zhao, Yanwen; Hu, Shuijin

2018-05-09

Qinghai-Tibetan Plateau is the most sensitive region to global warming on Earth. Qinghai Lake, the largest lake on the plateau, has experienced evident area variation during the past several decades. To quantify the area changes of Qinghai Lake, a satellite-based survey based on Landsat images from the 1980s to 2010s has been performed. In addition, meteorological data from all the seven available stations on Qinghai-Tibetan Plateau has been analyzed. Area of Qinghai Lake shrank ~2% during 1987-2005, and then increased ~3% from 2005-2016. Meanwhile, the average annual temperature increased 0.319 °C/10 y in the past 50 years, where the value is 0.415 °C/10 y from 2005-2016. The structural equation modeling (SEM) shows that precipitation is the primary factor influencing the area of Qinghai Lake. Moreover, temperature might be tightly correlated with precipitation, snow line, and evaporation, thereby indirectly causes alternations of the lake area. This study elucidated the significant area variation of water body on the Qinghai-Tibetan Plateau under global warming since 1980s.

Geocode of River Networks in Global Plateaus

NASA Astrophysics Data System (ADS)

Ni, J.; Wang, Y.; Wang, T.

2017-12-01

As typical hierarchical systems, river networks are of great significance to aquatic organisms and its diversity. Different aspects of river networks have been investigated in previous studies such as network structure, formation cause, material transport, nutrient cycle and habitat variation. Nevertheless, river networks function as biological habitat is far from satisfactory in plateau areas. This paper presents a hierarchical method for habitat characterization of plateau river networks with the geocode extracted from abiotic factors including historical geologic period, climate zone, water source and geomorphic process at different spatial scales. As results, characteristics of biological response with vertical differentiation within typical plateau river networks are elucidated. Altitude, climate and landform are of great influence to habitat and thereby structure of aquatic community, while diverse water source and exogenic action would influence biological abundance or spatiotemporal distribution. Case studies are made in the main stream of the Yellow River and the Yangtze River, respectively extended to the river source to Qinghai-Tibet Plateau, which demonstrate high potentials for decision making support to river protection, ecological rehabilitation and sustainable management of river ecosystems.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors (Eospalax baileyi).

PubMed

Zhao, Fang; Ma, Jun-Ying; Cai, Hui-Xia; Su, Jian-Ping; Hou, Zhi-Bin; Zhang, Tong-Zuo; Lin, Gong-Hua

2014-07-01

Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors (Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene (cox1) and two nuclear genes (pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite.

Molecular identification of Taenia mustelae cysts in subterranean rodent plateau zokors (Eospalax baileyi)

PubMed Central

ZHAO, Fang; ZHANG, Ming-Xia; MA, Jun-Ying; CAI, Hui-Xia; SU, Jian-Ping; CAI, Hui-Xia; HOU, Zhi-Bin; ZHANG, Tong-Zuo; LIN, Gong-Hua

2014-01-01

Cestode larvae spend one phase of their two-phase life cycle in the viscera of rodents, but cases of cestodes infecting subterranean rodents have only been rarely observed. To experimentally gain some insight into this phenomenon, we captured approximately 300 plateau zokors (Eospalax baileyi), a typical subterranean rodent inhabiting the Qinghai-Tibet Plateau, and examined their livers for the presence of cysts. Totally, we collected five cysts, and using a mitochondrial gene (cox1) and two nuclear genes (pepck and pold) as genetic markers, we were able to analyze the taxonomy of the cysts. Both the maximum likelihood and Bayesian methods showed that the cysts share a monophyly with Taenia mustelae, while Kimura 2-parameter distances and number of different sites between our sequences and T. mustelae were far less than those found between the examined sequences and other Taeniidae species. These results, alongside supporting paraffin section histology, imply that the cysts found in plateau zokors can be regarded as larvae of T. mustelae, illustrating that zokors are a newly discovered intermediate host record of this parasite. PMID:25017751

Recent advances on the tectonic and magmatic evolution of the Greater Tibetan Plateau: A special issue in honor of Prof. Guitang Pan

NASA Astrophysics Data System (ADS)

Zhu, Di-Cheng; Chung, Sun-Lin; Niu, Yaoling

2016-02-01

The Greater Tibetan Plateau, also known in China as the Qinghai-Tibet Plateau or the Qingzang Plateau, is a tectonic amalgamation of numbers of continental collision events from the northwest in the early Paleozoic to the southwest in the Cenozoic (cf. Dewey et al., 1988; Pan et al., 2012; Yin and Harrison, 2000). These collision events resulted in orogenic belts that record the prolonged albeit complex histories of opening and closing of Tethyan ocean basins and associated tectonic and magmatic responses (cf. Chung et al., 2005; Pan et al., 2012; Song et al., 2014; Yin and Harrison, 2000; Zhu et al., 2013, 2015). Although many aspects related to these events have been recently synthesized with elegance by Pan et al. (2012) and Zhu et al. (2013) using data and observations made available since 2000, many scientific questions, such as the duration of oceanic basins, the collisional and accretionary processes of different terranes, the processes responsible for crustal growth, and the mechanisms for economic mineralization, remain underdeveloped and require further investigations with additional data.

Crustal thickening in Gansu-Qinghai, lithospheric mantle subduction, and oblique, strike-slip controlled growth of the Tibet plateau

NASA Astrophysics Data System (ADS)

Meyer, B.; Tapponnier, P.; Bourjot, L.; Métivier, F.; Gaudemer, Y.; Peltzer, G.; Shunmin, Guo; Zhitai, Chen

1998-10-01

Fieldwork complemented by SPOT image analysis throws light on current crustal shortening processes in the ranges of northeastern Tibet (Gansu and Qinghai provinces, China). The ongoing deformation of Late-Pleistocene bajada aprons in the forelands of the ranges involves folding, at various scales, and chiefly north-vergent, seismogenic thrusts. The most active thrusts usually break the ground many kilometres north of the range-fronts, along the northeast limbs of growing, asymmetric ramp-anticlines. Normal faulting at the apex of other growing anticlines, between the range fronts and the thrust breaks, implies slip on blind ramps connecting distinct active décollement levels that deepen southwards. The various patterns of uplift of the bajada surfaces can be used to constrain plausible links between contemporary thrusts downsection. Typically, the foreland thrusts and décollements appear to splay from master thrusts that plunge at least 15-20 km down beneath the high ranges. Plio-Quaternary anticlinal ridges rising to more than 3000 m a.s.l. expose Palaeozoic metamorphic basement in their core. In general, the geology and topography of the ranges and forelands imply that structural reliefs of the order of 5-10 km have accrued at rates of 1-2 mm yr-1 in approximately the last 5 Ma. From hill to range size, the elongated reliefs that result from such Late-Cenozoic, NE-SW shortening appear to follow a simple scaling law, with roughly constant length/width ratio, suggesting that they have grown self-similarly. The greatest mountain ranges, which are over 5.5 km high, tens of kilometres wide and hundreds of kilometres long may thus be interpreted to have formed as NW-trending ramp anticlines, at the scale of the middle-upper crust. The fairly regular, large-scale arrangement of those ranges, with parallel crests separated by piggy-back basins, the coevality of many parallel, south-dipping thrusts, and a change in the scaling ratio (from ~5 to 8) for range widths greater than ~30 km further suggests that they developed as a result of the northeastward migration of large thrust ramps above a broad décollement dipping SW at a shallow angle in the middle-lower crust. This, in turn, suggests that the 400-500 km-wide crustal wedge that forms the northeastern edge of the Tibet-Qinghai plateau shortens and thickens as a thick-skinned accretionary prism decoupled from the stronger upper mantle underneath. Such a thickening process must have been coupled with propagation of the Altyn Tagh fault towards the ENE because most thrust traces merge northwestwards with active branches of this fault, after veering clockwise. This process appears to typify the manner in which the Tibet-Qinghai highlands have expanded their surface area in the Neogene. The present topography and structure imply that, during much of that period, the Tibet plateau grew predominantly towards the northeast or east-northeast, but only marginally towards the north-northwest. This was accomplished by the rise, in fairly fast succession, of the Arka Tagh, Qiman Tagh, Mahan shan, Tanghenan Shan, and other NW-trending mountain ranges splaying southeastwards from the Altyn Tagh, isolating the Aqqik-Ayakkum Kol, Qaidam, Suhai and other catchments and basins that became incorporated into the highland mass as intermontane troughs. The tectonic cut-off of catchments and the ultimate infilling of basins by debris from the adjacent ranges, a result of tectonically forced internal drainage, have thus been essential relief-smoothing factors, yielding the outstandingly flat topography that makes Tibet a plateau. Using Late-Mesozoic and Neogene horizons as markers, the retrodeformation of sections across the West Qilian Ranges and Qaidam basin implies at least ~150 km of N30°E Neogene shortening. On a broader scale, taking erosion into account, and assuming isostatic compensation and an initial crustal thickness comparable to that of the Gobi platform (47.5+/-5 km), minimum amounts of Late-Cenozoic crustal shortening on NE sections between the Kunlun fault and the Hexi corridor are estimated to range between 100 and 200 km. In keeping with the inference of a deep crustal décollement and with the existence of Mid-Miocene to Pliocene plutonism and volcanism south of the Kunlun range, such values suggest that the lithospheric mantle of the Qaidam plunged obliquely into the asthenosphere south of that range to minimum depths of the order of 200-300 km. A minimum of ~150 km of shortening in the last ~10 Ma, consistent with the average age of the earliest volcanic-plutonic rocks just south of the Kunlun (~10.8 Ma) would imply average Late-Cenozoic rates of shortening and regional uplift in NE Tibet of at least ~15 mm yr-1 and ~0.2 mm yr-1, respectively. Such numbers are consistent with a cumulative sinistral offset and slip rate of at least ~200 km and ~2 cm yr-1, respectively, on the Altyn Tagh fault east of 88°E. The fault may have propagated more than 1000 km, to 102°E, in the last 10 Ma. Our study of ongoing tectonics in northeast Tibet is consistent with a scenario in which, while the Himalayas-Gangdese essentially `stagnated' above India's subducting mantle, much of Tibet grew by thickening of the Asian crust, as propagation of large, lithospheric, strike-slip shear zones caused the opposite edge of the plateau to migrate far into Asia. The Asian lithospheric mantle, decoupled from the crust, appears to have subducted southwards along the two Mesozoic sutures that cut Tibet north of the Gangdese, rather than to have thickened. The Bangong-Nujiang suture was probably reactivated earlier than the Jinsha-Kunlun suture, located farther north. Overall, the large-scale deformation bears a resemblance to plate tectonics at obliquely convergent margins, including slip-partioning along large strike-slip faults such as the Altyn Tagh and Kunlun faults. Simple mechanisms at the level of the lithospheric mantle are merely hidden by the broader distribution and greater complexity of strain in the crust.

Records from Lake Qinghai: Holocene climate history of Northeastern Tibetan Plateau linking to global change

NASA Astrophysics Data System (ADS)

An, Z.; Colman, S.; Zhou, W.; Brown, E.; Li, X.; Jull, T.; Wang, S.; Liu, W.; Sun, Y.; Lu, X.; Song, Y.; Chang, H.; Cai, Y.; Xu, H.; Wang, X.; Liu, X.; Wu, F.; Han, Y.; Cheng, P.; Ai, L.; Wang, Z.; Qiang, X.; Shen, J.; Zhu, Y.; Wu, Z.; Liu, X.

2008-12-01

Lake Qinghai (99°36'-100°16'E, 36°32'-37°15'N ) of the north eastern margin of Tibet Plateau is the largest inland lake of China. It sits on the transitional zone of Asian monsoon- arid areas, receives influences of Asian monsoons and Westerlies, thus sensitive to global climate changes. Although previous studies had investigated Holocene climate change of Lake Qinghai area, it is rare to see precise Holocene climatic sequences of Lake Qinghai, nor in-depth discussions on controlling factors of Lake Qinghai climate changes. In Year 2005, with support from ICDP, Chinese Academy of Sciences (CAS), Chinese Ministry of Science and Technology (MOST) and National Science Foundation of China (NSFC), Drilling, Observation and Sampling of the Earths Continental Crust Corporation (DOSECC) and Institute of Earth Environment, Chinese Academy of Sciences (IEECAS) took a series of shallows cores from the southern basin of Lake Qinghai. West sub-basin sediments display Holocene lacustrine feature for the upper 5m, while the 5-18m are interbeded sediments of shallow lake, eolian-lacustrine and eolian loess. Chinese and US scientists with support from NSFC, MOST, CAS and NSF analysed 1F core from west sub-basin depocenter of the south basin with multiple physical, chemical, biological approaches. By comparing with modern process observation records, we obtained proxies that respectfully reflect precipitation, temperature and lake salinity changes, etc., reconstructed high resolution time sequences of magnetic susceptibility, colour scale, grain size, Corg, C/N, δ13Corg, carbonate, δ13C and δ18O of carbonate and ostracodes, elements, char-soot,Uk'37 and %C37:4 as well as pollen of the last 13Ka. They indicate the climatic change history of Lake Qinghai since past 13Ka, and agreeable evidences are found from adjacent tree ring and stalagmite records. Comparison of Lake Qinghai Holocene climate change sequence with those from high altitude ice core, stalagmites and ocean records for East Asian monsoon and Indian monsoon show that, in accordance with Asian monsoon climate changes, at 11-5ka cal. 14C BP Lake Qinghai revealed the warm and humid Optimal climate, while since 5ka cal.14C BP the Lake showed relatively cold and dry climate of New Glaciation, this orbital climate trend resembled northern hemisphere summer solar insolation changes. Lake Qinghai millennial-centennial climate events in Holocene are linked with Westerlies changes, and with East Asian summer monsoon front shift as well as winter monsoon, on centennial-decadal scale Lake Qinghai climate changes are controlled more by solar activities.

Review of risk factors for human echinococcosis prevalence on the Qinghai-Tibet Plateau, China: a prospective for control options

PubMed Central

2014-01-01

Objective Echinococcosis is a major parasitic zoonosis of public health importance in western China. In 2004, the Chinese Ministry of Health estimated that 380,000 people had the disease in the region. The Qinghai-Tibet Plateau is highly co-endemic with both alveolar echinococcosis (AE) and cystic echinococcosis (CE). In the past years, the Chinese government has been increasing the financial support to control the diseases in this region. Therefore, it is very important to identify the significant risk factors of the diseases by reviewing studies done in the region in the past decade to help policymakers design appropriate control strategies. Review Selection criteria for which literature to review were firstly defined. Medline, CNKI (China National Knowledge Infrastructure), and Google Scholar were systematically searched for literature published between January 2000 and July 2011. Significant risk factors found by single factor and/or multiple factors analysis were listed, counted, and summarized. Literature was examined to check the comparability of the data; age and sex specific prevalence with same data structures were merged and used for further analysis. A variety of assumed social, economical, behavioral, and ecological risk factors were studied on the Plateau. Those most at risk were Tibetan herdsmen, the old and female in particular. By analyzing merged comparable data, it was found that females had a significant higher prevalence, and a positive linearity relationship existed between echinococcosis prevalence and increasing age. In terms of behavioral risk factors, playing with dogs was mostly correlated with CE and/or AE prevalence. In terms of hygiene, employing ground water as the drinking water source was significantly correlated with CE and AE prevalence. For definitive hosts, dog related factors were most frequently identified with prevalence of CE or/and AE; fox was a potential risk factor for AE prevalence only. Overgrazing and deforestation were significant for AE prevalence only. Conclusion Tibetan herdsmen communities were at the highest risk of echinococcosis prevalence and should be the focus of echinococcosis control. Deworming both owned and stray dogs should be a major measure for controlling echinococcosis; treatment of wild definitive hosts should also be considered for AE endemic areas. Health education activities should be in concert with the local people’s education backgrounds and languages in order to be able to improve behaviors. Further researches are needed to clarify the importance of wild hosts for AE/CE prevalence, the extent and range of the impacts of ecologic changes (overgrazing and deforestation) on the AE prevalence, and risk factors in Tibet. PMID:24475907

Review of risk factors for human echinococcosis prevalence on the Qinghai-Tibet Plateau, China: a prospective for control options.

PubMed

Wang, Qian; Huang, Yan; Huang, Liang; Yu, Wenjie; He, Wei; Zhong, Bo; Li, Wei; Zeng, Xiangman; Vuitton, Dominique A; Giraudoux, Patrick; Craig, Philip S; Wu, Weiping

2014-01-29

Echinococcosis is a major parasitic zoonosis of public health importance in western China. In 2004, the Chinese Ministry of Health estimated that 380,000 people had the disease in the region. The Qinghai-Tibet Plateau is highly co-endemic with both alveolar echinococcosis (AE) and cystic echinococcosis (CE). In the past years, the Chinese government has been increasing the financial support to control the diseases in this region. Therefore, it is very important to identify the significant risk factors of the diseases by reviewing studies done in the region in the past decade to help policymakers design appropriate control strategies. Selection criteria for which literature to review were firstly defined. Medline, CNKI (China National Knowledge Infrastructure), and Google Scholar were systematically searched for literature published between January 2000 and July 2011. Significant risk factors found by single factor and/or multiple factors analysis were listed, counted, and summarized. Literature was examined to check the comparability of the data; age and sex specific prevalence with same data structures were merged and used for further analysis.A variety of assumed social, economical, behavioral, and ecological risk factors were studied on the Plateau. Those most at risk were Tibetan herdsmen, the old and female in particular. By analyzing merged comparable data, it was found that females had a significant higher prevalence, and a positive linearity relationship existed between echinococcosis prevalence and increasing age. In terms of behavioral risk factors, playing with dogs was mostly correlated with CE and/or AE prevalence. In terms of hygiene, employing ground water as the drinking water source was significantly correlated with CE and AE prevalence. For definitive hosts, dog related factors were most frequently identified with prevalence of CE or/and AE; fox was a potential risk factor for AE prevalence only. Overgrazing and deforestation were significant for AE prevalence only. Tibetan herdsmen communities were at the highest risk of echinococcosis prevalence and should be the focus of echinococcosis control. Deworming both owned and stray dogs should be a major measure for controlling echinococcosis; treatment of wild definitive hosts should also be considered for AE endemic areas. Health education activities should be in concert with the local people's education backgrounds and languages in order to be able to improve behaviors. Further researches are needed to clarify the importance of wild hosts for AE/CE prevalence, the extent and range of the impacts of ecologic changes (overgrazing and deforestation) on the AE prevalence, and risk factors in Tibet.

Factor analysis and cluster analysis research on the relationship between the trace elements of flowers of Gentianaceae plants and the traditional Chinese medicine efficacy from Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Zhou, Libing

2017-06-01

Flowers of Gentianaceae plants have historically been used in treating gastritis, dysuria, pruritus vulvae and detoxification. Gentianaceae plants have medicinal applications to treat a wide range of diseases such as rheumatic arthritis, pneumonia along with cough, chronic gastritis, et al Therefore, the research on the relationship between human health and trace elements of flowers of Gentianaceae plants is of great significance. These studies provide the scientific base and theoretical foundation for the future large-scale rational relation development of Gentianaceae plants resources as well as the relationship between the race elements of them and traditional Chinese medicine efficacy.

Estimating Air Temperature over the Tibetan Plateau Using MODIS Data

NASA Astrophysics Data System (ADS)

Huang, Fangfang; Ma, Weiqiang; Ma, Yaoming; Li, Maoshan; Hu, Zeyong

2016-04-01

Time series of MODIS land surface temperature (LST) data and normalized difference vegetation index (NDVI) data, combined with digital elevation model (DEM) and meterological data for 2001-2012, were used to estimate and map the spatial distribution of monthly mean air temperature over the Tibatan Plateau (TP). Time series and regression analysis of monthly mean land surface temperature (Ts) and air temperature (Ta) were both conducted by ordinary liner regression (OLR) and geographical weighted regression (GWR) methods. Analysis showed that GWR method had much better result (Adjusted R2 > 0.79, root mean square error (RMSE) is between 0.51° C and 1.12° C) for estimating Ta than OLR method. The GWR model, with MODIS LST, NDVI and altitude as independent variables, was used to estimate Ta over the Tibetan Plateau. All GWR models in each month were tested by F-test with significant level of α=0.01 and the regression coefficients were all tested by T-test with significant level of α=0.01. This illustrated that Ts, NDVI and altitude play an important role on estimating Ta over the Tibetan Plateau. Finally, the major conclusions are as follows: (1) GWR method has higher accuracy for estimating Ta than OLR (Adjusted R2=0.40˜0.78, RMSE=1.60˜4.38° C), and the Ta control precision can be up to 1.12° C. (2) Over the Northern TP, the range of Ta variation in January is -29.28 ˜ -5.0° C, and that in July is -0.53 ˜ 14.0° C. Ta in summer half year (from May to October) is between -15.92 ˜ 14.0° C. From October on, 0° C isothermal level is gradually declining from the altitude of 4˜5 kilometers, and hits the bottom with altitude of 3200 meters in December, and Ta is all under 0° C in January. 10° C isothermal level gradually starts rising from the altitude of 3200 meters from May, and reaches the highest level with altitude of 4˜5 kilometers in July. In addition, Ta in south slope of the Tanggula Mountains is obviously higher than that in the north slope. Ta in east of Qinghai-Tibet Railway is higher than that in the west, and Ta shows an increasing tendency from northwest to southeast. (3) Over the Northern TP, the variation range of the difference between surface and air temperature (DT) in January is -6.52˜6.0° C, and that in July is -6.32˜6.0° C. DT in summer half year (from May to October) is between -6.34˜8.0° C, and DT along Qinghai-Tibet Railway is greater than that in the east and west areas of Qinghai-Tibet Railway. However, except of the southeastern area of the Northern TP, where DT is under 0° C, DT values in other areas are all more than 0° C in winter half year. In summer half year, the altitude of the area lower than 0° C rises to 4˜5 kilometers, and DT in south of the Tanggula Mountains is between -2.0° C and 0° C.

Responses of Soil Microbial Communities to Experimental Warming in Alpine Grasslands on the Qinghai-Tibet Plateau

PubMed Central

He, Xingyuan; Liu, Wenjie; Zhao, Qian; Zhao, Lin; Tian, Chunjie

2014-01-01

Global surface temperature is predicted to increase by at least 1.5°C by the end of this century. However, the response of soil microbial communities to global warming is still poorly understood, especially in high-elevation grasslands. We therefore conducted an experiment on three types of alpine grasslands on the Qinghai-Tibet Plateau to study the effect of experimental warming on abundance and composition of soil microbial communities at 0–10 and 10–20 cm depths. Plots were passively warmed for 3 years using open-top chambers and compared to adjacent control plots at ambient temperature. Soil microbial communities were assessed using phospholipid fatty acid (PLFA) analysis. We found that 3 years of experimental warming consistently and significantly increased microbial biomass at the 0–10 cm soil depth of alpine swamp meadow (ASM) and alpine steppe (AS) grasslands, and at both the 0–10 and 10–20 cm soil depths of alpine meadow (AM) grasslands, due primarily to the changes in soil temperature, moisture, and plant coverage. Soil microbial community composition was also significantly affected by warming at the 0–10 cm soil depth of ASM and AM and at the 10–20 cm soil depth of AM. Warming significantly decreased the ratio of fungi to bacteria and thus induced a community shift towards bacteria at the 0–10 cm soil depth of ASM and AM. While the ratio of arbuscular mycorrhizal fungi to saprotrophic fungi (AMF/SF) was significantly decreased by warming at the 0–10 cm soil depth of ASM, it was increased at the 0–10 cm soil depth of AM. These results indicate that warming had a strong influence on soil microbial communities in the studied high-elevation grasslands and that the effect was dependent on grassland type. PMID:25083904

Seasonal and interannual dynamics of soil microbial biomass and available nitrogen in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Xu, Bo; Wang, Jinniu; Wu, Ning; Wu, Yan; Shi, Fusun

2018-01-01

Soil microbial activity varies seasonally in frozen alpine soils during cold seasons and plays a crucial role in available N pool accumulation in soil. The intra- and interannual patterns of microbial and nutrient dynamics reflect the influences of changing weather factors, and thus provide important insights into the biogeochemical cycles and ecological functions of ecosystems. We documented the seasonal and interannual dynamics of soil microbial and available N in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China, between April 2011 and October 2013. Soil was collected in the middle of each month and analyzed for water content, microbial biomass C (MBC) and N (MBN), dissolved organic C and N, and inorganic N. Soil microbial community composition was measured by the dilution-plate method. Fungi and actinomycetes dominated the microbial community during the nongrowing seasons, and the proportion of bacteria increased considerably during the early growing seasons. Trends of consistently increasing MBC and available N pools were observed during the nongrowing seasons. MBC sharply declined during soil thaw and was accompanied by a peak in available N pool. Induced by changes in soil temperatures, significant shifts in the structures and functions of microbial communities were observed during the winter-spring transition and largely contributed to microbial reduction. The divergent seasonal dynamics of different N forms showed a complementary nutrient supply pattern during the growing season. Similarities between the interannual dynamics of microbial biomass and available N pools were observed, and soil temperature and water conditions were the primary environmental factors driving interannual fluctuations. Owing to the changes in climate, seasonal soil microbial activities and nutrient supply patterns are expected to change further, and these changes may have crucial implications for the productivity and biodiversity of alpine ecosystems.

Dissolved inorganic and organic carbon yields and fluxes in a permafrost catchment on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Wang, G.; Mao, T.; Zhang, T.; Chen, X.

2015-12-01

Riverine transport of carbon from terrestrial to the aquatic ecosystems is an important component of the global carbon cycle. A warming climate can inevitably accelerate the microbial breakdown of organic carbon and the release of carbon dioxide especially in frozen soils (permafrost) within Arctic and sub-Arctic regions. In addition, high hydraulic conductivity and low sorption capacity of the shallow soil active layer overlying impermeable permafrost together lead to quick DOM transport to streams. In different regions, the response of dissolved carbon to climate warming is different due to the differences in hydrology, climatic conditions, soil types, vegetation conditions, permafrost distribution, catchment size, flow paths. The Qinghai-Tibet Plateau (QTP), of which a significant portion is underlain by permafrost, is considered to be more sensitive to climatic warming than other regions. However, the knowledge of dissolved inorganic and organic carbon transport in the QTP is very limited. We compared the yields and fluxes of DIC/DOC in a small tropical permafrost catchment. Our results showed that: (1) the concentrations ranged from 7.8 to 30.9 mg L-1 for the DIC and ranged from 2.3 to 6.4 mg L-1 for the DOC, the ratio of DIC/DOC concentrations ranged from 2.2 to 5.7 with a mean value of 4.3; (2) the annual export approximately 3.56 t km-2 year-1 for the DIC and 0.73 t km-2 year-1 for the DOC, indicating that the dissolved carbon transported in majority under the inorganic form; (3) the seasonal variations in DIC/DOC export are strongly regulated by variability in runoff, meanwhile the concentration of DIC/DOC showed significant positive correlation with the thawing depth of the active layer and vegetation coverage. Our results provided an understanding about the characteristics of riverine dissolved carbons transport at a permafrost catchment scale on the QTP.

Impacts of climate warming on the frozen ground and eco-hydrology in the Yellow River source region, China.

PubMed

Qin, Yue; Yang, Dawen; Gao, Bing; Wang, Taihua; Chen, Jinsong; Chen, Yun; Wang, Yuhan; Zheng, Guanheng

2017-12-15

The Yellow River source region is located in the transition region between permafrost and seasonally frozen ground on the northeastern Qinghai-Tibet Plateau. The region has experienced severe climate change, especially air temperature increases, in past decades. In this study, we employed a geomorphology-based eco-hydrological model (GBEHM) to assess the impacts of climate change on the frozen ground and eco-hydrological processes in the region. Based on a long-term simulation from 1981 to 2015, we found that the areal mean maximum thickness of seasonally frozen ground ranged from 1.1-1.8m and decreased by 1.2cm per year. Additionally, the ratio of the permafrost area to the total area decreased by 1.1% per year. These decreasing trends are faster than the average in China because the study area is on the sensitive margin of the Qinghai-Tibet Plateau. The annual runoff exhibited variations similar to those of the annual precipitation (R 2 =0.85), although the annual evapotranspiration (ET) exhibited an increasing trend (14.3mm/10a) similar to that of the annual mean air temperature (0.66°C/10a). The runoff coefficient (annual runoff divided by annual precipitation) displayed a decreasing trend because of the increasing ET, and the vegetation responses to climate warming and permafrost degradation were manifested as increases in the leaf area index (LAI) and ET at the start of the growing season. Furthermore, the results showed that changes to the frozen ground depth affected vegetation growth. Notably, a rapid decrease in the frozen ground depth (< -3.0cm/a) decreased the topsoil moisture and then decreased the LAI. This study showed that the eco-hydrological processes in the headwater area of the Yellow River have changed because of permafrost degradation, and these changes could further influence the water resources availability in the middle and lower reaches of the basin. Copyright © 2017 Elsevier B.V. All rights reserved.

Mapping vegetation cover and biomass on the Qinghai-Tibet-Plateau using hyperspectral measurements and multispectral satellite images

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Nauss, Thomas; Bendix, Jörg

2016-04-01

Pastoralism is the dominant land-use on the Qinghai-Tibet-Plateau (QTP) providing the major economic resource for the local population. However, the pastures are highly supposed to be affected by ongoing degradation whose extent is still disputed. This study uses hyperspectral in situ measurements and multispectral satellite images to assess vegetation cover and above ground biomass (AGB) as proxies of pasture degradation on a regional scale. Using Random Forests in conjunction with recursive feature selection as modeling tool, it is tested whether the full hyperspectral information is needed or if multispectral information is sufficient to accurately estimate vegetation cover and AGB. To regionalize pasture degradation proxies, the transferability of the locally derived models to high resolution multispectral satellite data is assessed. For this purpose, 1183 hyperspectral measurements and vegetation records were sampled at 18 locations on the QTP. AGB was determined on 25 0.5x0.5m plots. Proxies for pasture degradation were derived from the spectra by calculating narrow-band indices (NBI). Using the NBI as predictor variables vegetation cover and AGB were modeled. Models were calculated using the hyperspectral data as well as the same data resampled to WorldView-2, QuickBird and RapidEye channels. The hyperspectral results were compared to the multispectral results. Finally, the models were applied to satellite data to map vegetation cover and AGB on a regional scale. Vegetation cover was accurately predicted by Random Forest if hyperspectral measurements were used. In contrast, errors in AGB estimations were considerably higher. Only small differences in accuracy were observed between the models based on hyper- compared to multispectral data. The application of the models to satellite images generally resulted in an increase of the estimation error. Though this reflects the challenge of applying in situ measurements to satellite data, the results still show a high potential to map pasture degradation proxies on the QTP even for larger scales.

Spatiotemporal pattern of vegetation remote sensing phenology and its response to climatic factors on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

An, S.; Chen, X.

2015-12-01

Based on the MODIS MCD12Q2 remote sensing phenology product, we analyzed spatiotemporal variations of vegetation green-up, maturity, senescence and brown-off dates, and their relation to spatiotemporal patterns of air temperature and precipitation on the Qinghai-Tibet Plateau (QTP). From 2001 to 2012, phenological time series at about 11.7%~15.1% pixels indicate significant linear trends (P<0.1) with strong spatial consistency. Namely, pixels with significant phenological advancement and growing season lengthening are mainly distributed in the middle and eastern parts of the QTP, while pixels with significant phenological delay and growing season shortening are mainly distributed in the western and southern parts as well as the eastern edge of the QTP. Similar spatial patterns for positive and negative linear trends of the minimum and maximum EVI, and the time-integrated EVI during the growing season were detected in the above two regions, respectively. With regard to climatic factors, mean annual temperature shows an increased trend over the QTP except for the eastern edge, whereas annual precipitation displays an increased trend in the middle and eastern parts but a decreased trend in the western and southern parts as well as the eastern edge of the QTP. These findings suggest that phenological advancement, growing season lengthening, and vegetation activity enhancement in the middle and eastern parts might be attributed to coincident temperature and precipitation increase. By contrast, phenological delay, growing season shortening, and vegetation activity reduction in the western and southern parts as well as the eastern edge might be caused by opposite changes of temperature and precipitation, and strong evaporation induced water shortage. Furthermore, a partial correlation analysis indicates that green-up, maturity, and brown-off dates were influenced by preceding temperature and precipitation, while senescence date was affected by preceding precipitation.

Biological soil crust formation under artificial vegetation effect and its properties in the Mugetan sandy land, northeastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, Y. F.; Li, Z. W.; Jia, Y. H.; Zhang, K.

2016-08-01

Mugetan sandy land is an inland desertification area of about 2,065 km2 in the northeastern Qinghai-Tibet Plateau. In the ecological restoration region of the Mugetan sandy land, different crusts have formed under the action of vegetation in three types of sandy soil (i.e. semi-fixed sand dune, fixed sand dune and ancient fixed aeolian sandy soil). The surface sand particle distribution, mineral component and vegetation composition of moving sand dunes and three types of sandy soil were studied in 2010-2014 to analyze the biological crust formation properties in the Mugetan sandy land and the effects of artificial vegetation. Results from this study revealed that artificial vegetation increases the clay content and encourages the development of biological curst. The fine particles (i.e. clay and humus) of the surface layer of the sand dunes increased more than 15% ten years after the artificial vegetation planting, and further increased up to 20% after one hundred years. The interaction of clay, humus, and other fine particles formed the soil aggregate structure. Meanwhile, under the vegetation effect from the microbes, algae, and moss, the sand particles stuck together and a biological crust formed. The interconnection of the partial crusts caused the sand dunes to gradually be fixed as a whole. Maintaining the integrity of the biological crust plays a vital role in fixing the sand under the crust. The precipitation and temperature conditions in the Mugetan sandy land could satisfy the demand of biological crust formation and development. If rational vegetation measures are adopted in the region with moving sand dunes, the lichen-moss-algae biological curst will form after ten years, but it still takes more time for the sand dunes to reach the nutrient enrichment state. If the biological curst is partly broken due to human activities, reasonable closure and restoration measures can shorten the restoration time of the biological crust.

Spatiotemporal changes of freezing/thawing indices and their response to recent climate change on the Qinghai-Tibet Plateau from 1980 to 2013

NASA Astrophysics Data System (ADS)

Wu, Tonghua; Qin, Yanhui; Wu, Xiaodong; Li, Ren; Zou, Defu; Xie, Changwei

2018-05-01

The spatial and temporal changes of the ground surface freezing indices (GFIs), ground surface thawing indices (GTIs), air freezing indices (AFIs), and air thawing indices (ATIs) in permafrost and seasonally frozen ground regions of the Qinghai-Tibet Plateau (QTP) were analyzed based on the daily ground surface and air temperatures from 69 meteorological stations using the Mann-Kendall test and Sen's slope estimate. The spatial patterns of the freezing indices (FIs) and thawing indices (TIs) are nearly negatively correlated. On the annual scale, the GFI and GTI are greater than the AFI and ATI in both permafrost and seasonally frozen ground regions. The marked upward and downward trends have been observed for the time series of TI and FI, respectively, since 1998 on the QTP. Moreover, GFI and AFI decrease more significantly in permafrost regions than in seasonally frozen ground regions; the increasing rate of GTI and ATI in the seasonally frozen ground regions is greater than that in the permafrost regions. In permafrost regions, the downward trend of FI is greater than the upward trend of TI. However, the upward trend of TI shows a more drastic change than the FI in the seasonally frozen ground regions. The results indicate that the warming in the permafrost regions is more pronounced in winter than in the other seasons. The summer warming is more pronounced than the other seasons in the seasonally frozen ground regions. The decreasing rate of AFI and GFI increases as the altitude rises, while they decrease with increasing ATI. The average decreasing rate of GFI is greater than that of the AFI in different altitudinal zones. The greatest decrease of FI occurs in permafrost regions in the hinterland of the QTP, which indicates the dominant winter warming in this region. The downward trend of FI and upward trend of TI are responsible for the reported permafrost degradation on the QTP.

The geomorphology and evolution of aeolian landforms within a river valley in a semi-humid environment: A case study from Mainling Valley, Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Zhou, Na; Zhang, Chun-Lai; Wu, Xiao-Xu; Wang, Xun-ming; Kang, Li-qiang

2014-11-01

This paper systematically analyzes a valley's aeolian landforms in a semi-humid region and presents a model of its contemporary evolution. Mainling Valley of the Yarlung Zangbo River on the Qinghai-Tibet Plateau was chosen as the case study for the analysis of morphometric characteristics and the evolution sequence of aeolian landforms via field data and remote sensing images. The aeolian landforms were primarily composed of aeolian sand belts on river terraces and dunes (sheets) on hillside slopes. Three types of aeolian sand belts were identified based on their dune types. In type I belts, an erosive air stream combined with relatively high vegetation cover (10%) produced sparsely distributed parabolic dunes with a high variability of dune heights; in type II belts, the continual reworking by the erosive air stream in combination with low vegetation cover (3%) formed more densely distributed barchans and transitional dunes with a moderate variability of dune heights; and in type III belts, the gradual evolution from an erosive sand-laden air stream to a saturated sand-laden air stream in combination with low vegetation cover (2%) produced the densest crescentic dunefields but with the least variability in dune heights. Dune sizes increase, dune shapes become uniform, and dune distribution becomes close from type I to III belts. Lateral linking and merging of the dunes were also observed within the belts. Together this evidence indicates that an evolution sequence may exist. Aeolian dunefields in the belt appear to evolve from embryonic parabolic dunefields to adolescent barchan dunefields and, subsequently, to mature compound crescentic dunefields. As the aeolian sand belt evolves into the mature stage, sand accumulations at the foot of the mountain valley can be steps for sand accumulation on valley-side slopes.

Effects of local factors and climate on permafrost conditions and distribution in Beiluhe basin, Qinghai-Tibet Plateau, China.

PubMed

Yin, Guoan; Niu, Fujun; Lin, Zhanju; Luo, Jing; Liu, Minghao

2017-03-01

Beiluhe basin is underlain by warm and ice-rich permafrost, and covered by vegetation and soils characteristic of the Qinghai-Tibet Plateau. A field monitoring network was established to investigate permafrost conditions and to assess potential impacts of local factors and climate change. This paper describes the spatial variations in permafrost conditions from instrumented boreholes, controlling environmental factors, and recent thermal evolution of permafrost in the basin. The study area was divided into 10 ecotypes using satellite imagery based classification. The field investigations and cluster analysis of ground temperatures indicated that permafrost underlies most of the ground in swamp meadow, undisturbed alpine meadow, degrading alpine meadow, and desert alpine grassland, but is absent in other cover types. Permafrost-ecotope relations examined over a 2-year (2014-2016) period indicated that: (i) ground surface temperatures varied largely among ecotopes; (ii) annual mean ground temperatures ranged from -1.5 to 0°C in permafrost, indicating sensitive permafrost conditions; (iii) active-layer thicknesses ranged from 1.4m to 3.4m; (iv) ground ice content at the top of permafrost is high, but the active-layer soil is relatively dry. Long-term climate warming has driven thermal changes to permafrost, but ground surface characteristics and soil moisture content strongly influence the ground thermal state. These factors control local-scale spatial variations in permafrost conditions. The warm permafrost in the basin is commonly in thermal disequilibrium, and is sensitive to future climate change. Active-layer thicknesses have increased by at least 42cm and the mean annual ground temperatures have increased by up to 0.2°C in the past 10years over the basin. A permafrost distribution map was produced based on ecotypes, suggesting that permafrost underlies 64% of the study region. Copyright © 2017 Elsevier B.V. All rights reserved.

Unraveling of permafrost hydrological variabilities on Central Qinghai-Tibet Plateau using stable isotopic technique.

PubMed

Yang, Yuzhong; Wu, Qingbai; Hou, Yandong; Zhang, Zhongqiong; Zhan, Jing; Gao, Siru; Jin, Huijun

2017-12-15

Permafrost degradation on the Qinghai-Tibet Plateau (QTP) will substantially alter the surface runoff discharge and generation, which changes the recharge processes and influences the hydrological cycle on the QTP. Hydrological connections between different water bodies and the influence of thawing permafrost (ground ice) are not well understood on the QTP. This study applied water stable isotopic method to investigate the permafrost hydrological variabilities in Beiluhe Basin (BLB) on Central QTP. Isotopic variations of precipitation, river flow, thermokarst lake, and near-surface ground ice were identified to figure out the moisture source of them, and to elaborate the hydrological connections in permafrost region. Results suggested that isotopic seasonalities in precipitation is evident, it is showing more positive values in summer seasons, and negative values in winter seasons. Stable isotopes of river flow are mainly distributed in the range of precipitation which is indicative of important replenishment from precipitation. δ 18 O, δD of thermokarst lakes are more positive than precipitation, indicating of basin-scale evaporation of lake water. Comparison of δ I values in different water bodies shows that hydrology of thermokarst lakes was related to thawing of permafrost (ground ice) and precipitation. Near-surface ground ice in BLB exhibits different isotopic characteristics, and generates a special δD-δ 18 O relationship (freezing line): δD=5.81δ 18 O-23.02, which reflects typical freezing of liquid water. From isotopic analysis, it is inferred that near-surface ground ice was mainly recharged by precipitation and active layer water. Stable isotopic and conceptual model is suggestive of striking hydrological connections between precipitation, river flow, thermokarst lake, and ground ice under degrading permafrost. This research provides fundamental comprehensions into the hydrological processes in permafrost regions on QTP, which should be considered in investigating the influence of thawing permafrost on the hydrological cycle on QTP. Copyright © 2017 Elsevier B.V. All rights reserved.

Streptococcus halotolerans sp. nov. isolated from the respiratory tract of Marmota himalayana in Qinghai-Tibet Plateau of China.

PubMed

Niu, Lina; Lu, Shan; Hu, Shoukui; Jin, Dong; Lai, Xinhe; Yang, Jing; Chen, Cuixia; Wang, Yiting; Bai, Xiangning; Lan, Ruiting; Lv, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

2016-10-01

Two Gramstaining-positive, catalase-negative, α-hemolytic, coccus-shaped organisms were isolated separately from the respiratory tracts of two Marmota himalayana animals from the Qinghai-Tibet Plateau, PR China. Morphological, biological, biochemical, and molecular genetic studies were performed on these two isolates (HTS9T and HTS12). Their biochemical characteristics, such as acid production from different sugars and enzymatic activities, indicated that they represented a member of the genus Streptococcus. They are most closely related to Streptococcus thoraltensis CIP 105518T based on sequence analysis of their 16S rRNA, groEL, sodA and rpoB genes, with similarities of 97.6, 89.9, 92.6 and 91.1 % the four genes respectively. The whole genome phylogenetic tree reconstructed using 372 core genes from 65 genomes of members of the genus Streptococcus validates that HTS9T forms a distinct subline and exhibits specific phylogenetic affinity with S. thoraltensis. In silico DNA-DNA hybridization of HTS9T showed a DNA reassociation value of 32.1 %, closest to that of S. thoraltensis CIP 105518T. Based on their phenotypic characteristics and in particular the phylogenetic findings (DNA-DNA hybridization, three phylogenetic trees built from the partial 16S rRNA/housekeeping genes, and from 372 core genes of 65 genomes of members of the genus Streptococcus), we propose with confidence that strains HTS9T and HTS12 should be classified as representing a novel species of the genus Streptococcus, Streptococcus halotolerans sp. nov. The type strain is HTS9T (=DSM 101996T=CGMCC1.15532T). Genome analysis of Streptococcus halotolerans sp. nov. shows that its genome is 1 823 556 bp long with a DNA G+C content of 39.9 mol% and contains 2068 genes.

Diet simplification selects for high gut microbial diversity and strong fermenting ability in high-altitude pikas.

PubMed

Li, Huan; Qu, Jiapeng; Li, Tongtong; Wirth, Stephan; Zhang, Yanming; Zhao, Xinquan; Li, Xiangzhen

2018-06-03

The gut microbiota in mammals plays a key role in host metabolism and adaptation. However, relatively little is known regarding to how the animals adapts to extreme environments through regulating gut microbial diversity and function. Here, we investigated the diet, gut microbiota, short-chain fatty acid (SCFA) profiles, and cellulolytic activity from two common pika (Ochotona spp.) species in China, including Plateau pika (Ochotona curzoniae) from the Qinghai-Tibet Plateau and Daurian pika (Ochotona daurica) from the Inner Mongolia Grassland. Despite a partial diet overlap, Plateau pikas harbored lower diet diversity than Daurian pikas. Some bacteria (e.g., Prevotella and Ruminococcus) associated with fiber degradation were enriched in Plateau pikas. They harbored higher gut microbial diversity, total SCFA concentration, and cellulolytic activity than Daurian pikas. Interestingly, cellulolytic activity was positively correlated with the gut microbial diversity and SCFAs. Gut microbial communities and SCFA profiles were segregated structurally between host species. PICRUSt metagenome predictions demonstrated that microbial genes involved in carbohydrate metabolism and energy metabolism were overrepresented in the gut microbiota of Plateau pikas. Our results demonstrate that Plateau pikas harbor a stronger fermenting ability for the plant-based diet than Daurian pikas via gut microbial fermentation. The enhanced ability for utilization of plant-based diets in Plateau pikas may be partly a kind of microbiota adaptation for more energy requirements in cold and hypoxic high-altitude environments.

Impacts of Environmental Heterogeneity on Moss Diversity and Distribution of Didymodon (Pottiaceae) in Tibet, China.

PubMed

Song, Shanshan; Liu, Xuehua; Bai, Xueliang; Jiang, Yanbin; Zhang, Xianzhou; Yu, Chengqun; Shao, Xiaoming

2015-01-01

Tibet makes up the majority of the Qinghai-Tibet Plateau, often referred to as the roof of the world. Its complex landforms, physiognomy, and climate create a special heterogeneous environment for mosses. Each moss species inhabits its own habitat and ecological niche. This, in combination with its sensitivity to environmental change, makes moss species distribution a useful indicator of vegetation alteration and climate change. This study aimed to characterize the diversity and distribution of Didymodon (Pottiaceae) in Tibet, and model the potential distribution of its species. A total of 221 sample plots, each with a size of 10 × 10 m and located at different altitudes, were investigated across all vegetation types. Of these, the 181 plots in which Didymodon species were found were used to conduct analyses and modeling. Three noteworthy results were obtained. First, a total of 22 species of Didymodon were identified. Among these, Didymodon rigidulus var. subulatus had not previously been recorded in China, and Didymodon constrictus var. constrictus was the dominant species. Second, analysis of the relationships between species distributions and environmental factors using canonical correspondence analysis revealed that vegetation cover and altitude were the main factors affecting the distribution of Didymodon in Tibet. Third, based on the environmental factors of bioclimate, topography and vegetation, the distribution of Didymodon was predicted throughout Tibet at a spatial resolution of 1 km, using the presence-only MaxEnt model. Climatic variables were the key factors in the model. We conclude that the environment plays a significant role in moss diversity and distribution. Based on our research findings, we recommend that future studies should focus on the impacts of climate change on the distribution and conservation of Didymodon.

Impacts of Environmental Heterogeneity on Moss Diversity and Distribution of Didymodon (Pottiaceae) in Tibet, China

PubMed Central

Song, Shanshan; Bai, Xueliang; Jiang, Yanbin; Zhang, Xianzhou; Yu, Chengqun

2015-01-01

Tibet makes up the majority of the Qinghai-Tibet Plateau, often referred to as the roof of the world. Its complex landforms, physiognomy, and climate create a special heterogeneous environment for mosses. Each moss species inhabits its own habitat and ecological niche. This, in combination with its sensitivity to environmental change, makes moss species distribution a useful indicator of vegetation alteration and climate change. This study aimed to characterize the diversity and distribution of Didymodon (Pottiaceae) in Tibet, and model the potential distribution of its species. A total of 221 sample plots, each with a size of 10 × 10 m and located at different altitudes, were investigated across all vegetation types. Of these, the 181 plots in which Didymodon species were found were used to conduct analyses and modeling. Three noteworthy results were obtained. First, a total of 22 species of Didymodon were identified. Among these, Didymodon rigidulus var. subulatus had not previously been recorded in China, and Didymodon constrictus var. constrictus was the dominant species. Second, analysis of the relationships between species distributions and environmental factors using canonical correspondence analysis revealed that vegetation cover and altitude were the main factors affecting the distribution of Didymodon in Tibet. Third, based on the environmental factors of bioclimate, topography and vegetation, the distribution of Didymodon was predicted throughout Tibet at a spatial resolution of 1 km, using the presence-only MaxEnt model. Climatic variables were the key factors in the model. We conclude that the environment plays a significant role in moss diversity and distribution. Based on our research findings, we recommend that future studies should focus on the impacts of climate change on the distribution and conservation of Didymodon. PMID:26181326

Aeolian Sediments on the northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Stauch, G.; Lehmkuhl, F.

2013-12-01

The timing and spatial distribution of aeolian sediments on the northeastern Tibetan Plateau have gained increasing interest during the last decades. The formation of the aeolian deposits is often related to cold and dry climate conditions. However, further important parameters are the local geomorphological setting and sediment availability in the source areas of the sediments. Aeolian sediments including loess, sandy loess and sands are widespread in the catchment of the Donggi Cona on the northeastern Tibetan Plateau at around 4000 m asl. Detailed geomorphological mapping of the deposits and geochemical analyses of the sediments revealed varying sources throughout the Holocene. The timing of the sediment deposition is based on 43 OSL (optical stimulated luminescence) ages. Several phases of enhanced aeolian deposition took place during the Holocene. The accumulation of aeolian sands lasted from 10.5 until 7 ka. The main source area of these sands was a large alluvial fan. Parallel to the formation of the dunes loess was deposited on the adjacent slopes from 10.5 until 7.5 ka. These sediments most probably originate in the nearby Qaidam Basin. In contrast to the general linkage of aeolian sediments to dryer climate conditions formation of these aeolian deposits is related to wetter conditions due to a strengthening of the Asian Summer Monsoons. The wetter climate enhanced the trapping and continuous fixation of the aeolian sediments by vegetation. With the further strengthening of the Monsoon fluvial processes eroded the aeolian deposits at least until 6 ka. From about 3 ka to the present a reactivation of aeolian sands and the formation of new dunes took place. This reactivation is related to drier conditions on the north-eastern Tibetan Plateau. Additionally, an increased human influence might have enhanced the aeolian activity. Similar phases of enhanced aeolian activity have been documented in more than 170 available OSL ages from loess and aeolian sands in northeastern Tibet. In the area of the Qinghai Lake enhanced accumulation of sand took place between 16 and 7 ka, while in the Gonghe Basin and the eastern Qaidam Basin sand was deposited between 13 and 7.5 ka. A late Holocene reactivation of sand similar to the Donggi catchment is only known from the Qinghai Lake area. The OSL ages of loess samples are generally younger than the ages of aeolian sand in northeastern Tibet. In the surrounding of the Qinghai Lake loess accumulation took place between 14.5 and 8ka while the loess ages from the eastern Qaidam Basin are mainly between 10.5 and 4.5 ka. In the Gonghe Basin only four ages of late Holocene ages are available. A different picture emerges from the northeastern margin of the study area. Loess accumulation on the northern slopes of the Qilian Shan occurred throughout the Holocene. In this area the nearby desert regions provide a more or less constant supply of silt-sized particles. In all other areas studied on the northeastern Tibetan Plateau the accumulation of aeolian sediments is primarily controlled by environmental conditions in the accumulation areas.

Investigations of kinetics and mechanism of chloropinnoite in boric acid aqueous solution at 303 K by Raman spectroscopy.

PubMed

Xiaoping, Li; Shiyang, Gao; Shuping, Xia

2004-10-01

Raman spectroscopy of dissolution and transformation of chloropinnoite in 4.5% (wt.%) boric acid aqueous solution at 303 K has been recorded. The Raman spectra of kinetics process have been obtained. The phase transformation product is 2MgO.3B2O3.15H2O (kurnakovite). The main polyborate anions and their interaction in aqueous solution have been proposed according to the Raman spectrum. Some assignments were tentatively given and the relations between the existing forms of polyborate anions and the crystallizing solid phases have been gained. A mechanism of dissolution and crystallization reactions and the formation condition of kurnakovite in Qinghai-Tibet plateau were proposed and discussed.

[Raman spectroscopic analysis of dissolution and phase transformation of chloropinnoite in the boric acid aqueous solution].

PubMed

Li, Xiao-Ping; Gao, Shi-Yang; Liu, Zhi-Hong; Hu, Man-Cheng; Xia, Shu-Ping

2005-01-01

Raman spectroscopy of dissolution and transformation of chloropinnoite in 4.5% (w.t.%) boric acid aqueous solution at 30 degrees C has been recorded. The Raman spectra of kinetics process have been obtained. The phase transformation product is kurnakovite (2MgO x 3B2O3 x 15H2O). The main polyborate anions and their interaction in aqueous solution have been proposed according to the Raman spectrum. Some assignments were tentatively given and the relations between the existing forms of polyborate anions and the crystallizing solid phases have been gained. A mechanisms of dissolution and crystallization reactions and the formation condition of kurnakovite in Qinghai-Tibet plateau were proposed and discussed.

Preliminary study on alterations of altitude road traffic in China from 2006 to 2013

PubMed Central

Zhao, Hui; Yin, Zhiyong; Xiang, Hongyi; Liao, Zhikang; Wang, Zhengguo

2017-01-01

Introduction Road traffic can play an important role in strengthening regional economic activities, especially at high altitude, and it is necessary to know important traffic-related information. Although previous studies reported on road traffic in China, there has been little research on high-altitude road traffic to date. Method The annual official census of road traffic safety from 2006 to 2013 was used to obtain data on the general population, registered drivers, registered vehicles, newly built roads, road traffic accidents (RTAs), mortality rate per 100 000 populations and per 10 000 vehicles in high-altitude provinces, including Tibet, Qinghai, Xinjiang, Gansu, Yunnan, Sichuan, and Chongqing. These provincial data were reviewed retrospectively, with the national data as the reference. Statistical analysis (i.e., t test) was used to compare the estimated average annual change rate of population, number of registered drivers, registered vehicles, and newly built roads in high-altitude provinces with the national rates. Results Compared with the national data, there are significantly higher annual rates of population growth in Tibet and Xinjiang, registered drivers in Gansu, registered vehicles in Gansu, Sichuan, and Chongqing, and newly built roads in Tibet and Qinghai. Among the investigated provinces, Tibet, Qinghai, and Yunnan had a higher proportion of the roads with the high class. RTAs and RTA-induced casualties in the high-altitude provinces indicated a decreasing trend. The mortality rate per 10 000 vehicles and per 100 000 populations showed a decreasing trend, while the RTA-related mortality rate in Tibet, Qinghai, Xinjiang and Gansu remained high. Conclusions Major changes for road traffic in high-altitude provinces have occurred over the past decade; however, the RTA-related mortality rate in high-altitude provinces has remained high. This study furthers understanding about road traffic safety in China; further studies on road traffic safety at high altitude should be performed. PMID:28187203

Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

PubMed

Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

2016-06-01

Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

Crust-mantle density distribution in the eastern Qinghai-Tibet Plateau revealed by satellite-derived gravity gradients

NASA Astrophysics Data System (ADS)

LI, Honglei; Fang, Jian; Braitenberg, Carla; Wang, Xinsheng

2015-04-01

As the highest, largest and most active plateau on Earth, the Qinghai-Tibet Plateau has a complex crust-mantle structure, especially in its eastern part. In response to the subduction of the lithospheric mantle of the Indian plate, large-scale crustal motion occurs in this area. Despite the many previous studies, geodynamic processes at depth remain unclear. Knowledge of crust and upper mantle density distribution allows a better definition of the deeper geological structure and thus provides critically needed information for understanding of the underlying geodynamic processes. With an unprecedented precision of 1-2 mGal and a spatial resolution better than 100 km, GOCE (Gravity field and steady-state Ocean Circulation Explorer) mission products can be used to constrain the crust-mantle density distribution. Here we used GOCE gravitational gradients at an altitude of 10km after reducing the effects of terrain, sediment thickness variations, and Moho undulations to image the density structures of eastern Tibet up to 200 km depths. We inverted the residual satellite gravitational gradients using a least square approach. The initial density model for the inversion is based on seismic velocities from the tomography. The model is composed of rectangular blocks, having a uniform density, with widths of about 100 km and variable thickness and depths. The thickness of the rectangular cells changes from10 to 60km in accordance with the seismic model. Our results reveal some large-scale, structurally controlled density variations at depths. The lithospheric root defined by higher-density contrast features from southwest to northeast, with shallowing in the central part: base of lithosphere reaches a depth of180 km, less than 100km, and 200 km underneath the Lhasa, Songpan-Ganzi, and Ordos crustal blocks, respectively. However, these depth values only represent a first-order parameterization because they depend on model discretization inherited from the original seismic tomography model. For example, the thickness of the uniform density blocks centered at140 km depth is as large as 60 km. Low-density crustal anomalies beneath the southern Lhasa and Songpan-Ganzi blocks in our model support the idea of weak lower crust and possible crustal flow, as a result of the thermal anomalies caused by the upwelling of hot deep materials. The weak lower crust may cause the decoupling of the upper crust and the mantle. These results are consistent with many other geophysical studies, confirming the effectiveness of the GOCE gravitational gradient data. Using these data in combination with other geodynamic constraints (e.g., gravity and seismic structure and preliminary reference Earth model), an improved dynamic model can be derived.

Characteristics of ground motion at permafrost sites along the Qinghai-Tibet railway

USGS Publications Warehouse

Wang, L.; Wu, Z.; Sun, Jielun; Liu, Xiuying; Wang, Z.

2009-01-01

Based on 14 typical drilling holes distributed in the permafrost areas along the Qinghai-Tibet railway, the distribution of wave velocities of soils in the permafrost regions were determined. Using results of dynamic triaxial tests, the results of dynamic triaxiality test and time histories of ground motion acceleration in this area, characteristics of ground motion response were analyzed for these permafrost sites for time histories of ground accelerations with three exceedance probabilities (63%, 10% and 2%). The influence of ground temperature on the seismic displacement, velocity, acceleration and response spectrum on the surface of permafrost were also studied. ?? 2008 Elsevier Ltd. All rights reserved.

Genetic structuring and recent demographic history of red pandas (Ailurus fulgens) inferred from microsatellite and mitochondrial DNA.

PubMed

Hu, Yibo; Guo, Yu; Qi, Dunwu; Zhan, Xiangjiang; Wu, Hua; Bruford, Michael W; Wei, Fuwen

2011-07-01

Clarification of the genetic structure and population history of a species can shed light on the impacts of landscapes, historical climate change and contemporary human activities and thus enables evidence-based conservation decisions for endangered organisms. The red panda (Ailurus fulgens) is an endangered species distributing at the edge of the Qinghai-Tibetan Plateau and is currently subject to habitat loss, fragmentation and population decline, thus representing a good model to test the influences of the above-mentioned factors on a plateau edge species. We combined nine microsatellite loci and 551 bp of mitochondrial control region (mtDNA CR) to explore the genetic structure and demographic history of this species. A total of 123 individuals were sampled from 23 locations across five populations. High levels of genetic variation were identified for both mtDNA and microsatellites. Phylogeographic analyses indicated little geographic structure, suggesting historically wide gene flow. However, microsatellite-based Bayesian clustering clearly identified three groups (Qionglai-Liangshan, Xiaoxiangling and Gaoligong-Tibet). A significant isolation-by-distance pattern was detected only after removing Xiaoxiangling. For mtDNA data, there was no statistical support for a historical population expansion or contraction for the whole sample or any population except Xiaoxiangling where a signal of contraction was detected. However, Bayesian simulations of population history using microsatellite data did pinpoint population declines for Qionglai, Xiaoxiangling and Gaoligong, demonstrating significant influences of human activity on demography. The unique history of the Xiaoxiangling population plays a critical role in shaping the genetic structure of this species, and large-scale habitat loss and fragmentation is hampering gene flow among populations. The implications of our findings for the biogeography of the Qinghai-Tibetan Plateau, subspecies classification and conservation of red pandas are discussed. © 2011 Blackwell Publishing Ltd.

Climate and its change over the Tibetan Plateau and its Surroundings in 1963-2015

NASA Astrophysics Data System (ADS)

Ding, J.; Cuo, L.

2017-12-01

Tibetan Plateau and its surroundings (TPS, 23°-43°N, 73°-106°E) lies in the southwest of China and includes Tibet Autonomous Region, Qinghai Province, southern Xinjiang Uygur Autonomous Region, part of Gansu Province, western Sichuan Province, and northern Yunnan Province. The region is of strategic importance in water resources because it is the headwater of ten large rivers that support more than 16 billion population. In this study, we use daily temperature maximum and minimum, precipitation and wind speed in 1963-2015 obtained from Climate Data Center of China Meteorological Administration and Qinghai Meteorological Bureau to investigate extreme climate conditions and their changes over the TPS. The extreme events are selected based on annual extreme values and percentiles. Annual extreme value approach produces one value each year for all variables, which enables us to examine the magnitude of extreme events; whereas percentile approach selects extreme values by setting 95th percentile as thresholds for maximum temperature, precipitation and wind speed, and 5th percentile for minimum temperature. Percentile approach not only enables us to investigate the magnitude but also frequency of the extreme events. Also, Mann-Kendall trend and mutation analysis were applied to analyze the changes in mean and extreme conditions. The results will help us understand more about the extreme events during the past five decades on the TPS and will provide valuable information for the upcoming IPCC reports on climate change.

Preliminary study of atmospheric carbon dioxide in a glacial area of the Qilian Mountains, west China

NASA Astrophysics Data System (ADS)

Li, Chuanjin; Zhou, Lingxi; Qin, Dahe; Liu, Lixin; Qin, Xiang; Wang, Zebin; Ren, Jiawen

2014-12-01

Carbon dioxide represents the most important contribution to increased radiative forcing. The preliminary results of the atmospheric carbon dioxide mole fraction from the glacial region in the Qilian Mountains area, in the northeast of the Qinghai-Xizang (Tibetan) Plateau during July, 2009 to October, 2012 are presented. The annual mean CO2 mole fractions in 2010 and 2011 were 388.4 ± 2.7 ppm and 392.7 ± 2.6 ppm, respectively. These values were consistent with the CO2 mole fractions from the WMO/GAW stations located at high altitudes. However, both the concentration and seasonal variation were significantly lower than stations located adjacent to megacities or economic centers at low latitudes in eastern China. Shorter durations of photosynthesis of the alpine vegetation system that exceeded respiration were detected at the Qilian Mountains glacial area. The annual mean increase during the sampling period was 2.9 ppm yr-1 and this value was higher than the global mean values. Anthropogenic activities in the cities adjacent to the Qilian Mountains may have important influences on the CO2 mole fractions, especially in summer, when north and north-north-west winds are typical.

Inventory of the carabid beetle fauna of the Gaoligong Mountains, western Yunnan Province, China: species of the tribe Zabrini (Coleoptera, Carabidae)

PubMed Central

Kavanaugh, David H.; Hieke, Fritz; Liang, Hongbin; Dong, Dazhi

2014-01-01

Abstract A ten-year multidisciplinary, multi-national and multi-institutional biodiversity inventory project in the Gaoligong Shan region of western Yunnan Province, China generated more than 35,000 specimens of the beetle (Coleoptera) family Carabidae. In this report, first of a planned series, we focus on diversity in tribe Zabrini. Our study of just over 1300 specimens of zabrine carabids from the project, all in genus Amara Bonelli, found a total of 13 species, all previously described, to occur in the study area, with none of them strictly endemic. We present a key for identification of adults of these species, as well as nomenclatural data, diagnoses, illustrations of dorsal habitus and male genitalia, and information about geographical, altitudinal and habitat distributions within the study area and overall geographical distribution for each species. Distributions of the species within the study area are compared, and broader geographical range patterns are characterized. We also discuss a possible role of the Gaoligong Shan region as one source area for the present-day fauna of the Himalaya and southern edge of the Qinghai-Xizang (Tibetan) Plateau. PMID:24899831

Genetic characterization of H9N2 avian influenza virus in plateau pikas in the Qinghai Lake region of China.

PubMed

Yan, Yan; Gu, Jin-Yan; Yuan, Zhuang-Chuan; Chen, Xin-Yu; Li, Zeng-Kui; Lei, Jing; Hu, Bo-Li; Yan, Li-Ping; Xing, Gang; Liao, Min; Zhou, Ji-Yong

2017-04-01

Qinghai Lake is a major migratory-bird breeding site that has experienced several highly pathogenic avian influenza virus (AIV) epizootics. Plateau pikas (Ochotona curzoniae) have previously been implicated in the ecology of avian influenza virus in this region. We first isolated an H9N2 AIV (A/Pika/Menyuan/01/2008) from plateau pikas between November 2008 and October 2009. Sequence analysis showed that the A/Pika/Menyuan/01/2008 AIV was closely related to the H9N2 AIV strain (A/Turkey/Wisconsin/ 1/1966). Our findings suggested that plateau pikas may contribute to AIV epidemiology in the Qinghai Lake region.

From local spectral measurements to maps of vegetation cover and biomass on the Qinghai-Tibet-Plateau: Do we need hyperspectral information?

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Nauss, Thomas; Bendix, Jörg

2017-03-01

Though the relevance of pasture degradation on the Qinghai-Tibet Plateau (QTP) is widely postulated, its extent is still unknown. Due to the enormous spatial extent, remote sensing provides the only possibility to investigate pasture degradation via frequently used proxies such as vegetation cover and aboveground biomass (AGB). However, unified remote sensing approaches are still lacking. This study tests the applicability of hyper- and multispectral in situ measurements to map vegetation cover and AGB on regional scales. Using machine learning techniques, it is tested whether the full hyperspectral information is needed or if multispectral information is sufficient to accurately estimate pasture degradation proxies. To regionalize pasture degradation proxies, the transferability of the locally derived ML-models to high resolution multispectral satellite data is assessed. 1183 hyperspectral measurements and vegetation records were performed at 18 locations on the QTP. Random Forests models with recursive feature selection were trained to estimate vegetation cover and AGB using narrow-band indices (NBI) as predictors. Separate models were calculated using NBI from hyperspectral data as well as from the same data resampled to WorldView-2, QuickBird and RapidEye channels. The hyperspectral results were compared to the multispectral results. Finally, the models were applied to satellite data to map vegetation cover and AGB on a regional scale. Vegetation cover was accurately predicted by Random Forest if hyperspectral measurements were used (cross validated R2 = 0.89). In contrast, errors in AGB estimations were considerably higher (cross validated R2 = 0.32). Only small differences in accuracy were observed between the models based on hyperspectral compared to multispectral data. The application of the models to satellite images generally resulted in an increase of the estimation error. Though this reflects the challenge of applying in situ measurements to satellite data, the results still show a high potential to map pasture degradation proxies on the QTP. Thus, this study presents robust methodology to remotely detect and monitor pasture degradation at high spatial resolutions.

Monitoring Functional Traits of Alpine Vegetation using Remote Sensing

NASA Astrophysics Data System (ADS)

Li, C.; Wulf, H.; Schaepman, M. E.; Schmid, B.

2016-12-01

Plant functional traits can be used to study the interactions between plants and ecosystem functioning as well as the response of plants to various environmental pressures. Continuous monitoring of plant functional traits dynamics on a large spatial scale is important to understand the mechanisms of ecosystem function degradation, especially on the Qinghai-Tibet Plateau. In this study, we investigated spatiotemporal trends of functional traits (i.e., chlorophyll content, phenology, leaf area index proxy of leaf size and above ground biomass proxy of leaf mass) in the eastern part of the Qinghai-Tibet Plateau based on the combined analysis of multi-sensor satellite data and field observations at three spatial scales (ground-truth data at 1 m, Landsat at 30 m, MODIS at 500 m), and analyzed potential factors contribute to their spatiotemporal trends. Chlorophyll content (Chl) and biomass was retrieved based on 94 field plots measurements. LAI was analyzed using MCD15A3H product and estimated values using digital hemispherical photographs in the field. Plant phenology will be processed based on MODIS NDVI time series and hourly Phenocam observations. The preliminary results show that (1) Chl, LAI and biomass show high spatial heterogeneity trends and increase in 2001 - 2015. (2) Elevation played an important role in the spatial pattern of LAI and Chl variation in 15 years. A dividing line of approximately 3800 m exists and shows that below this line, LAI and Chl changes more complicated, showing significantly positive and negative linear trend. While above this altitude, the change rate of two variables keeps relatively stable. Vegetation in low elevation is exposed to high habitat diversity by showing high Chl, LAI and biomass spatial heterogeneity. The vegetation in high habitat diversity may be more sensitive to climatic variables and human activities than higher elevation since warming contribute to the positive trend of traits while human factors like urbanization might be explain negative trend in relative low altitude (below 3800 m). (3) Temperature contribute to the above functional traits variation than precipitation, especially temperature is more correlated to the functional traits of widely distributed vegetation type than narrow-ranging vegetation type.

Evaluation of thermokarst lake water balance in the Qinghai-Tibet Plateau via isotope tracers.

PubMed

Gao, Zeyong; Niu, Fujun; Lin, Zhanju; Luo, Jing; Yin, Guoan; Wang, Yibo

2018-04-24

Thermokarst lakes are a ubiquitous landscape feature, which widely distributed in the pan-arctic and some low latitude regions, and are associated with regional hydrological processes. The studies were taken to obtain a better understanding of the water balance of thermokarst lakes in the Qinghai-Tibet Plateau (QTP) in order to gain insight of the regional hydrological cycle. The characteristics of the stable isotopes δ 18 O and δ D were investigated in precipitation, permafrost meltwater, and thermokarst lake water in the continuous permafrost region of the QTP and analyzed the lake water balance using the isotope mass model. The results showed that the δ D-δ 18 O relationship in the thermokarst lakes (δ D = 5.45 δ 18 O - 18.95) differed from that of the local precipitation (δ D = 8.30 δ 18 O + 18.49) and permafrost meltwater (δ D = 5.78 δ 18 O - 23.41), and the mean isotope compositions in the thermokarst lakes were -7.2‰ in δ 18 O and -58.0‰ in δ D. The more positive isotope signals in thermokarst lakes than in the precipitation and permafrost meltwater revealed that the lakes had experienced stronger isotope enrichment. Additionally, the evaporation-to-inflow ratio (E/I) values were < 1 in most of the thermokarst lakes (84%), which might be explained by the recent expansion of the lake surfaces. However, 16% of the thermokarst lakes had shrunk, owing to thermokarst erosion, lateral expansion as the temperature increases, and lower recharge volume. Moreover, precipitation on the lake surface was only 14-18% of the inflow volume in the thermokarst lakes, and the surface-subsurface inflow and permafrost meltwater are very important for recharging the lakes and maintaining the water balance. The results of this study provide a comprehensive understanding of the influence of climate warming on hydrological processes in the permafrost regions in the QTP. Copyright © 2018 Elsevier B.V. All rights reserved.

Geometry and kinematics of Majiatan Fold-and-thrust Belt, Western Ordos Basin: implication for Tectonic Evolution of North-South Tectonic Belt

NASA Astrophysics Data System (ADS)

He, D.

2017-12-01

The Helan-Chuandian North-South Tectonic Belt crossed the central Chinese mainland. It is a boundary of geological, geophysical, and geographic system of Chinese continent tectonics from shallow to deep, and a key zone for tectonic and geomorphologic inversion during Mesozoic to Cenozoic. It is superimposed by the southeastward and northeastward propagation of Qinghai-Tibet Plateau in late Cenozoic. It is thus the critical division for West and East China since Mesozoic. The Majiatan fold-and-thrust belt (MFTB), locating at the central part of HCNSTB and the western margin of Ordos Basin, is formed by the tectonic evolution of the Helan-Liupanshan Mountains. Based on the newly-acquired high-resolution seismic profiles, deep boreholes, and surface geology, the paper discusses the geometry, kinematics, and geodynamic evolution of MFTB. With the Upper Carboniferous coal measures and the pre-Sinian ductile zone as the detachments, MFTB is a multi-level detached thrust system. The thrusting was mainly during latest Jurassic to Late Cretaceous, breaking-forward in the foreland, and resulting in a shortening rate of 25-29%. By structural restoration, this area underwent extension in Middle Proterozoic to Paleozoic, which can be divided into three phases of rifting such as Middle to Late Proterozoic, Cambiran to Ordovician, and Caboniferous to early Permian. It underwent compression since Late Triassic, including such periods as Latest Triassic, Late Jurassic to early Cretaceous, Late Cretaceous to early Paleogene, and Pliocene to Quaternary, with the largest shortening around Late Jurassic to early Cretaceous period (i.e. the mid-Yanshanian movement by the local name). However, trans-extension since Eocene around the Ordos Basin got rise to the formation the Yingchuan, Hetao, and Weihe grabens. It is concluded that MFTB is the leading edge of the intra-continental Helan orogenic belt, and formed by multi-phase breaking-forward thrusting during Late Jurassic to Cretaceous. During Cenozoic, MFTB is moderately modified by the northeastward compression due to the NE propagation of Qinghai-Tibet Plateau, and distinctly superimposed by the Yingchuan half-graben. North-South Tectonic Belt underwent a full cycle from extension during Middle Proterozoic to Paleozoic to compression since late Triassic.

Climate warming over the past half century has led to thermal degradation of permafrost on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Ran, Youhua; Li, Xin; Cheng, Guodong

2018-02-01

Air temperature increases thermally degrade permafrost, which has widespread impacts on engineering design, resource development, and environmental protection in cold regions. This study evaluates the potential thermal degradation of permafrost over the Qinghai-Tibet Plateau (QTP) from the 1960s to the 2000s using estimated decadal mean annual air temperatures (MAATs) by integrating remote-sensing-based estimates of mean annual land surface temperatures (MASTs), leaf area index (LAI) and fractional snow cover values, and decadal mean MAAT date from 152 weather stations with a geographically weighted regression (GWR). The results reflect a continuous rise of approximately 0.04 °C a-1 in the decadal mean MAAT values over the past half century. A thermal-condition classification matrix is used to convert modelled MAATs to permafrost thermal type. Results show that the climate warming has led to a thermal degradation of permafrost in the past half century. The total area of thermally degraded permafrost is approximately 153.76 × 104 km2, which corresponds to 88 % of the permafrost area in the 1960s. The thermal condition of 75.2 % of the very cold permafrost, 89.6 % of the cold permafrost, 90.3 % of the cool permafrost, 92.3 % of the warm permafrost, and 32.8 % of the very warm permafrost has been degraded to lower levels of thermal condition. Approximately 49.4 % of the very warm permafrost and 96 % of the likely thawing permafrost has degraded to seasonally frozen ground. The mean elevations of the very cold, cold, cool, warm, very warm, and likely thawing permafrost areas increased by 88, 97, 155, 185, 161, and 250 m, respectively. The degradation mainly occurred from the 1960s to the 1970s and from the 1990s to the 2000s. This degradation may lead to increased risks to infrastructure, reductions in ecosystem resilience, increased flood risks, and positive climate feedback effects. It therefore affects the well-being of millions of people and sustainable development at the Third Pole.

Applying GIPL2.0 Model to assess the permafrost dynamics on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Wu, T.

2017-12-01

The modeling of active layer and permafrost distribution is of great importance to understand the permafrost dynamics of cold regions, especially in those regions where are difficult to approach such as the Qinghai-Tibet Plateau (QTP). In this study we have applied the Geophysical Institute Permafrost Lab model (GIPL2.0) to estimate the active layer thickness and assess the permafrost thermal regime on the QTP. The GIPL 2.0 have been widely applied in the Arctic regions of Alaska, however less on the QTP. The model has been calibrated according to the four active layer in-situ measurement sites which have different underlying surface and soil characteristics. We extended the original GIPL2 model depth to the depth of 18 m. After the calibration of the GIPL2.0 at those four sites, the first-hand single point model is expanded to a regional model. The key permafrost parameters were simulated, including active layer thickness (ALT), mean annual ground temperature (MAGT) at multiple soil layers, and the permafrost classification was also carried out in order to study the permafrost the thermal stability across the QTP. To validate the performance of expanded regional-GIPL2 model, we compare simulated ALT and MAGT at the depth of zero annual amplitude (DZAA) with observed data. It is demonstrated that the modifications regional-GIPL2 model are able to improve the accuracy of permafrost thermal regime simulations greatly on the QTP. The simulated ALT are generally underestimate the observed ones with the MBE value of -0.14 m and the RMSE value of 0.22 m. For the MAGT at the DZAA of all 51 sites, the simulation errors range from - 0.9 ° to 0.9 ° with the RMSE value of 0.41 °. For the whole permafrost area of the QTP, the simulated ALT ranges from 0 to 8 m, with an average of 2.30 m. The simulated results indicate that most of regions were underlain by the sub-stable permafrost and less regions were underlain by the extremely stable permafrost.

Dramatic and long-term lake level changes in the Qinghai-Tibet Plateau from Cryosat-2 altimeter: validation and augmentation by results from repeat altimeter missions and satellite imagery

NASA Astrophysics Data System (ADS)

Hwang, Cheinway; Huang, YongRuei; Cheng, Ys; Shen, WenBin; Pan, Yuanjin

2017-04-01

The mean elevation of the Qinghai-Tibet Plateau (QTP) exceeds 4000 m. Lake levels in the QTP are less affected by human activities than elsewhere, and may better reflect the state of contemporary climate change. Here ground-based lake level measurements are rare. Repeat altimeter missions, particularly those from the TOPEX and ERS series of altimetry, have provided long-term lake level observations in the QTP, but their large cross-track distances allow only few lakes to be monitored. In contrast, the Cryosat-2 altimeter, equipped with the new sensor SIRAL (interferometric/ synthetic aperture radar altimeter), provides a much better ranging accuracy and a finer spatial coverage than these repeated missions, and can detect water level changes over a large number of lakes in the QTP. In this study, Cryosat-2 data are used to determine lake level changes over 75˚E-100˚E and 28˚N-37.5˚N, where Cryosat-2 covers 60 lakes and SARAL/ AltiKa covers 32 lakes from 2013 to 2016. Over a lake, Cryosat-2 in different cycles can pass through different spots of the lake, making the numbers of observations non-uniform and requiring corrections for lake slopes. Four cases are investigated to cope with these situations: (1) neglecting inconsistency in data volume and lake slopes (2) considering data volume, (3) considering lake slopes only, and (4) considering both data volume and lake slopes. The CRYOSAT-2 result is then compared with the result from the SARAL to determine the best case. Because Cryosat-2 is available from 2010 to 2016, Jason-2 data are used to fill gaps between the time series of Cryosat-2 and ICESat (2003-2009) to obtain >10 years of lake level series. The Cryosat-2 result shows dramatic lake level rises in Lakes Kusai, Zhuoaihu and Salt in 2011 caused by floods. Landsat satellite imagery assists the determination and interpretation of such rises.

The Wenquan ultramafic rocks in the Central East Kunlun Fault zone, Qinghai-Tibet Plateau—crustal relics of the Paleo-Tethys ocean

NASA Astrophysics Data System (ADS)

Jia, Lihui; Meng, Fancong; Feng, Huibin

2018-06-01

The Wenquan ultramafic rocks, located in the East Kunlun Orogenic belt in the northeastern part of the Qinghai-Tibet Plateau, consist of dunite, wehrlite, olivine-clinopyroxenite and clinopyroxenite, and exhibit cumulate textures. Olivine from dunite has high Fo (forsterite, 90.0-91.8 wt%) and NiO content (0.15-0.42 wt%). Cr-spinels from all of the rocks in this suite are characterized by high Cr# (100×[Cr/(Cr + Al)], 67-91), low Mg# (100×[Mg/(Mg + Fe2+)], 17-35) and low TiO2 contents (mostly < 0.5 wt%). Clinopyroxene displays high Mg# (92-98) and low TiO2 content (0.002-0.099 wt%), similar to those in ophiolitic cumulates. Geochemically, the Wenquan ultramafic rocks show enrichment of LILE, Sr, and Ba, and depletion of Nb and Th. High-Mg# (mostly > 80) and low-CaO (< 0.08 wt%) olivine, high-Cr# (up to 91) spinel, and low Ti contents of clinopyroxene and Cr-spinel indicate that the Wenquan cumulates were generated by high-degree partial melting of a depleted oceanic lithosphere mantle. The ultramafic intrusion most likely evolved from high-Mg basaltic magmas (Mg# = 77.5) that underwent fractional crystallization and crustal contamination. Zircon grains from clinopyroxenites yield a U-Pb weighted mean age of 331 ± 2 Ma, which is nearly coeval with the formation age of the A'nyemaqen ophiolites. The Wenquan Carboniferous ophiolites are confirmed to exist in the Central East Kunlun Fault zone, whereas previous studies have considered them to be the Proterozoic ophiolites. The Wenquan ophiolite might be a relict of the Paleotethyan ocean, indicating that there were two cycles of oceanic-continental evolution along the Central East Kunlun Fault zone.

Radiocarbon reservoir between charred seeds and fish bone in Neolithic sites, northeastern Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zhou, A.; Dong, G.; Ren, L.

2017-12-01

Many efforts have been done to understand the reservoir effect of Qinghai Lake, yet no agreement has been reached. Five archaeological sites, located around the junction between the estuary of Rivers and Qinghai Lake, are the earliest Neolithic Age sites in the Qinghai- Tibetan Plateau (QTP), which is critical for understanding patterns of prehistoric human inhabitation in the high plateau extreme environments. This study compares radiocarbon dates of fish bones and terrestrial plant remains uncovered from the same archaeological strata to see whether there was reservoir effect reference to reliable data. Results demonstrate that there were reservoir effects ranging from 300 to 600 years back to 3600 years ago, nevertheless, no reservoir was observed of the modern fish. Besides, stable isotopic analysis illustrated that modern fish consumed similar food to those of millennias ago.

EDITORIAL: Integrated assessments of environmental change on the Tibetan Plateau Integrated assessments of environmental change on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Sheng, Yongwei; Yao, Tandong

2009-12-01

The Tibetan Plateau is one of the Earth's most sensitive regions in responding to climate change due to its extremely high altitude and the presence of permafrost and glaciers. The cryosphere, biosphere and hydrosphere of the plateau have been undergoing significant changes. Due to the low human population density, environmental changes on the plateau are largely driven by natural processes. Thus, the plateau provides a unique and comprehensive site for global change studies. This focus issue on Climate Change on the Tibetan Plateau aims to address both paleo and recent environmental changes across the plateau to facilitate our understanding of this remote and under-studied area. We invited a wide spectrum of contributions to address climate change, permafrost degradation, glacier/snow/ice dynamics, lake dynamics, land- cover/land-use changes, and their interactions on the plateau. Collectively, the diverse contributions in this special issue are expected to present the recent advancement of the above topics and beyond. See the PDF for the full text of the editorial. Focus on Climate Change on the Tibetan Plateau Contents Does a weekend effect in diurnal temperature range exist in the eastern and central Tibetan Plateau? Qinglong You, Shichang Kang, Wolfgang-Albert Flügel, Arturo Sanchez-Lorenzo, Yuping Yan, Yanwei Xu and Jie Huang Diurnal variations of summertime precipitation over the Tibetan Plateau in relation to orographically-induced regional circulations Xiaodong Liu, Aijuan Bai and Changhai Liu Lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, investigated using optically stimulated luminescence dating of beach ridges Dewen Li, Yingkui Li, Baoqi Ma, Guocheng Dong, Liqiang Wang and Junxiang Zhao Recent changes in Imja Glacial Lake and its damming moraine in the Nepal Himalaya revealed by in situ surveys and multi-temporal ASTER imagery Koji Fujita, Akiko Sakai, Takayuki Nuimura, Satoru Yamaguchi and Rishi R Sharma Changes in frozen ground in the Source Area of the Yellow River on the Qinghai-Tibet Plateau, China, and their eco-environmental impacts Huijun Jin, Ruixia He, Guodong Cheng, Qingbai Wu, Shaoling Wang, Lanzhi Lü and Xiaoli Chang A shallow ice core re-drilled on the Dunde Ice Cap, western China: recent changes in the Asian high mountains Nozomu Takeuchi, Takayuki Miyake, Fumio Nakazawa, Hideki Narita, Koji Fujita, Akiko Sakai, Masayoshi Nakawo, Yoshiyuki Fujii, Keqin Duan and Tandong Yao Review of climate and cryospheric change in the Tibetan Plateau Shichang Kang, Yanwei Xu, Qinglong You, Wolfgang-Albert Flügel, Nick Pepin and Tandong Yao Simulated impacts of land cover change on summer climate in the Tibetan Plateau Qian Li and Yongkang Xue

Isolation and characterization of a new enterovirus F in yak feces in the Qinghai-Tibetan Plateau.

PubMed

He, Huan; Tang, Cheng; Chen, Xinnuo; Yue, Hua; Ren, Yupeng; Liu, Yan; Zhang, Bin

2017-02-01

An enterovirus (EV) strain, designated as SWUN-AB001, was isolated in the Qinghai-Tibetan Plateau from a yak with severe diarrheal disease. The complete genome of strain SWUN-AB001 was 7,382 bp in length and shared 35.1-68.5% nt identities with bovine EVs belonging to a candidate new type EV-F7. Using the sequence difference values in the VP1 gene as a criterion for demarcating a new serotype/genotype in the Enterovirus genus, strain SWUN-AB001 had only a 71.1% nt and a 79.2% aa identity, in the VP1 region, with the most closely matched EV, further indicating that a new type of EV had been identified. Phylogenetic analysis of the nt sequence of the viral polyprotein and of VP1 genes demonstrated that the virus fell within the EV-F cluster, but was located in a unique lineage. Furthermore, a large-scale surveillance study indicated that the prevalence of this EV in yaks was 31.05% (95% CI = 25.5-37.6%) in 235 animals with diarrhea and 24.13% (95% CI = 17.4-32.4%) in 116 healthy yaks. However, there was no significant difference in virus prevalence between diarrheal and healthy samples. Interestingly, in the Tibet region, diarrheal feces had a higher incidence of EVs than feces of healthy yaks (odd ratios = 6.03, 95% CI = 1.93-18.86), indicating that the incidence of EV was potentially correlated with the clinical symptom of diarrhea in yaks.

The relationship between the opening of South China Sea and the formation of the Tibetan Plateau (Invited)

NASA Astrophysics Data System (ADS)

Mo, X.

2010-12-01

The South China Sea is one of the largest marginal seas in western Pacific and underwent a complex history. Xu et al.(2004) suggested that the evolution of the South China Sea can be divided into two first order phases: Paleogene (—Early Miocene) rifting and Neogene post- rifting. An oceanic crust was formed during 32-17 Ma. Whether or not the opening of South China Sea were related to Indo-Eurasia collision and the formation of the Tibetan Plateau is one of challenging problem in Earth sciences. With an exception of the southwestern China, the Chinese continent has become an united continent in the Triassic by the Indosinian orogeny. However, the Qinghai-Tibet area in SW China was still an oceanic region, that is, the Neo-Tethys. During the period of 145-100 Ma, the Lhasa terrane collided with the Qiangtang terrane and added to the south margin of the Eurasian continent. On the other hand, the Indian plate subducted underneath the Eurasian continent since Jurassic- Cretaceous. Subsequently, collision between the two continents, India and Eurasia, were completed during 65-40 Ma, and went into a post-collisional stage, characterized by intra-continental movements, including intra-continental subduction, overthrust, strike-slip and so on. The Tibetan Plateau, the highest plateau in the world had been formed by multi-stage uplifts. Several huge strike-slip shear zone such as the Red River Fault and the Altyn were formed during that period. The >1000-km-long Oligocene—Miocene left-lateral Red River shear zone (RRSZ) and the Pliocene—active right-lateral Red River fault (RRF), stretching from SE Tibet to the South China Sea, has been cited as a lithospheric scale strike-slip fault. The age of RRSZ was recently determined no earlier than 31.9-24.2Ma and no later than 21.7 Ma (Searle et al., 2010). Many geologists believe that there possibly be close relationship between the opening of the South China Sea and Indo-Eurasia collision and the formation of the Tibetan Plateau via the evolution of the Red River shear zone.

[Responses of normalized difference vegetation index (NDVI) to precipitation changes on the grassland of Tibetan Plateau from 2000 to 2015.

PubMed

Wang, Zhi Peng; Zhang, Xian Zhou; He, Yong Tao; Li, Meng; Shi, Pei Li; Zu, Jia Xing; Niu, Ben

2018-01-01

Precipitation change is an important factor in the inter-annual variation of grassland growth on the Tibetan Plateau. The total amount, distribution pattern and concentration time are three basic characteristics of precipitation change. The temporal and spatial characteristics of precipitation change were analyzed based on climate data of 145 meteorological stations on the Tibetan Plateau and nearby areas from 2000 to 2015. The total precipitation amount was characterized by annual precipitation, distribution pattern of precipitation during the year was characterized by improved precipitation concentration index (PCI), and precipitation centroid (PC) was defined to indicate the change in precipitation concentrated time. To better illustrate the response of grassland to precipitation change, vegetation growth status was characterized by the maximum value of normalized difference vegetation index (NDVI max ). Results indicated that the annual precipitation and PCI had an apparent gradient across the whole plateau and the latest PC occurred in the southern plateau. NDVI max of alpine shrub grassland was significantly correlated with the change of PCI,increased with even distribution of precipitation during growth period, and limited by the total annual precipitation. Alpine meadow did not show significantly correlations with these three indices. The inter-annual variability of NDVI max of steppe was controlled by both PCI and PC. NDVI max of alpine desert grassland was mainly controlled by annual precipitation. In addition to annual total amount of precipitation, the distribution characteristics of precipitation should be further considered when the influence of precipitation change on different types of vegetation on the Qinghai Tibet Plateau was studied.

Water chemistry in the rives of the permafrost regions on the eastern Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wu, X.; Ma, X.; Ye, L.; Liu, G.

2017-12-01

Qinghai-Tibetan is the largest middle-low latitude permafrost areas on the world. There are several large rivers in the plateau, and the changes of the water resources of these rivers are associated with the water resource security of more than 1.35 billion people. Due to the high gradients, these rivers have a tremendous amount of potential energy for electricity output. To promote economic and social development and provide clean energy, hydropower development has taken place on several rivers which originate on the Qinghai-Tibetan Plateau. Since dam construction affect the flow velocity, water temperature, sediments delivery as well as organic matter and nitrogen, it is important to investigate the river chemistry in the head rivers of the reservoirs. We examined the water physio-chemical characteristics in the rivers under the typical vegetation types in the eastern Qinghai-Tibetan Plateau, and further analyzed their relationship to vegetation. The results showed that the total suspended sediment in the rivers were higher within the catchment of alpine steppe, with the lowest dissolved organic carbon content. In contrast, the rivers within the meadow had the highest dissolved organic carbon and lowest total suspension sediment. The dissolved organic carbon significantly positively correlated with the proportions of the meadow and wet meadow in the catchment. The pH, turbidity, and SUVA254 and dissolved organic carbon also correlated with each other. The results suggest that the vegetation type strongly affect the water chemistry in the permafrost regions on the Qinghai-Tibetan Plateau.

Yak whole-genome resequencing reveals domestication signatures and prehistoric population expansions.

PubMed

Qiu, Qiang; Wang, Lizhong; Wang, Kun; Yang, Yongzhi; Ma, Tao; Wang, Zefu; Zhang, Xiao; Ni, Zhengqiang; Hou, Fujiang; Long, Ruijun; Abbott, Richard; Lenstra, Johannes; Liu, Jianquan

2015-12-22

Yak domestication represents an important episode in the early human occupation of the high-altitude Qinghai-Tibet Plateau (QTP). The precise timing of domestication is debated and little is known about the underlying genetic changes that occurred during the process. Here we investigate genome variation of wild and domestic yaks. We detect signals of selection in 209 genes of domestic yaks, several of which relate to behaviour and tameness. We date yak domestication to 7,300 years before present (yr BP), most likely by nomadic people, and an estimated sixfold increase in yak population size by 3,600 yr BP. These dates coincide with two early human population expansions on the QTP during the early-Neolithic age and the late-Holocene, respectively. Our findings add to an understanding of yak domestication and its importance in the early human occupation of the QTP.

Yak whole-genome resequencing reveals domestication signatures and prehistoric population expansions

PubMed Central

Qiu, Qiang; Wang, Lizhong; Wang, Kun; Yang, Yongzhi; Ma, Tao; Wang, Zefu; Zhang, Xiao; Ni, Zhengqiang; Hou, Fujiang; Long, Ruijun; Abbott, Richard; Lenstra, Johannes; Liu, Jianquan

2015-01-01

Yak domestication represents an important episode in the early human occupation of the high-altitude Qinghai-Tibet Plateau (QTP). The precise timing of domestication is debated and little is known about the underlying genetic changes that occurred during the process. Here we investigate genome variation of wild and domestic yaks. We detect signals of selection in 209 genes of domestic yaks, several of which relate to behaviour and tameness. We date yak domestication to 7,300 years before present (yr BP), most likely by nomadic people, and an estimated sixfold increase in yak population size by 3,600 yr BP. These dates coincide with two early human population expansions on the QTP during the early-Neolithic age and the late-Holocene, respectively. Our findings add to an understanding of yak domestication and its importance in the early human occupation of the QTP. PMID:26691338

Development of Three PCR Assays for the Differentiation between Echinococcus shiquicus, E. granulosus (G1 genotype), and E. multilocularis DNA in the Co-Endemic Region of Qinghai-Tibet plateau, China

PubMed Central

Boufana, Belgees; Umhang, Gérald; Qiu, Jiamin; Chen, Xingwang; Lahmar, Samia; Boué, Franck; Jenkins, David; Craig, Philip

2013-01-01

To investigate echinococcosis in co-endemic regions, three polymerase chain reaction (PCR) assays based on the amplification of a fragment within the NADH dehydrogenase subunit 1 (ND1) mitochondrial gene were optimized for the detection of Echinococcus shiquicus, Echinococcus granulosus G1, and Echinococcus multilocularis DNA derived from parasite tissue or canid fecal samples. Specificity using parasite tissue-derived DNA was found to be 100% except for E. shiquicus primers that faintly detected E. equinus DNA. Sensitivity of the three assays for DNA detection was between 2 and 10 pg. Ethanol precipitation of negative PCR fecal samples was used to eliminate false negatives and served to increase sensitivity as exemplified by an increase in detection from 0% to 89% of E. shiquicus coproDNA using necropsy-positive fox samples. PMID:23438764

The Cold Hardiness of Phrynocephalus erythrurus, the Lizard Living at Highest Altitude in the World.

PubMed

Li, X T; Wang, Y; Lu, S S; Li, M; Men, S K; Bai, Y C; Tang, X L; Chen, Q

Phrynocephalus erythrurus living at Qinghai-Tibet Plateau, is believed to be the highest lizard in the world, but we know little about how these lizards cope with very low temperatures in winter. The aim of this study was to find the difference of the lizards before and after cold acclimatization. In this study the limit of supercooling and inoculative freezing, the concentration of four organic osmolytes, and the activity of lactate dehydrogenase in the plasma were measured in samples shortly after capture and in other samples after 7~8 weeks of acclimatization at 2~4 degree C. Animals acquired an ability to undergo deeper supercooling and inoculative freezing through the course of acclimatization. We find no regular changes of the four organic osmolytes after the acclimatization. We think that this species of lizard is partly freeze-tolerant and conclude that it uses supercooling to survive in winter.

Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

PubMed

Li, Qiang; Wang, Xiaoming

2015-01-01

This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet.

Variation and significance of surface heat after the mechanical sand control of Qinghai-Tibet Railway was covered with sandy sediments

NASA Astrophysics Data System (ADS)

Xie, Shengbo; Qu, Jianjun; Mu, Yanhu; Xu, Xiangtian

Mechanical control of drifting sand used to protect the Qinghai-Tibet Railway from sand damage inevitably results in sand deposition, and the change in radiation and heat flux after the ground surface is covered with sandy sediments remains unclear. These variations were studied in this work through field observations along with laboratory analyses and tests. After the ground surface was covered with sandy sediments produced by the mechanical control of sand in the Qinghai-Tibet Railway, the reflectivity increased, and the annual average reflectivity on the surface covered with sandy sediments was higher than that without sandy sediments, with the value increasing by 0.043. Moreover, the surface shortwave radiation increased, whereas the surface net radiation decreased. The annual average value of the surface shortwave radiant flux density on the sandy sediments was higher than that without sandy sediments, with the value increasing by 7.291 W·m-2. The annual average value of the surface net radiant flux density on the sandy sediments decreased by 9.639 W·m-2 compared with that without sandy sediments. The soil heat flux also decreased, and the annual average value of the heat flux in the sandy sediments decreased by 0.375 W·m-2 compared with that without sandy sediments. These variations caused the heat source on the surface of sandy sediments underground to decrease, which is beneficial for preventing permafrost from degradation in the section of sand control of the railway.

Geothermal fields of China

NASA Astrophysics Data System (ADS)

Kearey, P.; HongBing, Wei

1993-08-01

There are over 2500 known occurrences of geothermal phenomena in China. These lie mainly in four major geothermal zones: Xizang (Tibet)-Yunnan, Taiwan, East Coast and North-South. Hot water has also been found in boreholes in major Mesozoic-Cenozoic sedimentary basins. This paper presents a summary of present knowledge of these geothermal zones. The geological settings of geothermal occurrences are associated mainly with magmatic activity, fault uplift and depressional basins and these are described by examples of each type. Increased multipurpose utilisation of geothermal resources is planned and examples are given of current usages.

Qualitative Exploration of the Potential Causes of Serious Reduction in Availability of Medicinal Plants in the Qinghai-Tibetan High Plateau

PubMed Central

Cuomu, Mingji

2014-01-01

In the last ten years, there has been a dramatic reduction in medicinal plants in Tibet. This situation has attracted the attention of many researchers from different professional backgrounds, yet very few documents have been published on the general theoretical context and the actual process of herb collection as it occurs at different levels in clinics in Tibet. This article begins with a systematic review of the general principles of medicinal plant collection methods as set out in the ancient traditional medical system. Because the demand for plants is generated by the need to make Tibetan medicines, it is necessary to consider the original context of Tibetan medicine to understand pharmacological needs and the principles behind collecting medicinal plants to develop a strategy that might guarantee sustainable development of the plant supply. After considering the wider context of this study, the article presents research mainly based on case studies with the intention of understanding different stakeholders’ experiences and social relationships in the contemporary herb collection process in order to discover behavioral patterns within the dynamic social roles involved in this process as these inform policy formation and to seek to promote appropriate methods in the future. PMID:25478035

Moho topography, ranges and folds of Tibet by analysis of global gravity models and GOCE data

PubMed Central

Shin, Young Hong; Shum, C.K.; Braitenberg, Carla; Lee, Sang Mook; Na, Sung -Ho; Choi, Kwang Sun; Hsu, Houtse; Park, Young-Sue; Lim, Mutaek

2015-01-01

The determination of the crustal structure is essential in geophysics, as it gives insight into the geohistory, tectonic environment, geohazard mitigation, etc. Here we present the latest advance on three-dimensional modeling representing the Tibetan Mohorovičić discontinuity (topography and ranges) and its deformation (fold), revealed by analyzing gravity data from GOCE mission. Our study shows noticeable advances in estimated Tibetan Moho model which is superior to the results using the earlier gravity models prior to GOCE. The higher quality gravity field of GOCE is reflected in the Moho solution: we find that the Moho is deeper than 65 km, which is twice the normal continental crust beneath most of the Qinghai-Tibetan plateau, while the deepest Moho, up to 82 km, is located in western Tibet. The amplitude of the Moho fold is estimated to be ranging from −9 km to 9 km with a standard deviation of ~2 km. The improved GOCE gravity derived Moho signals reveal a clear directionality of the Moho ranges and Moho fold structure, orthogonal to deformation rates observed by GPS. This geophysical feature, clearly more evident than the ones estimated using earlier gravity models, reveals that it is the result of the large compressional tectonic process. PMID:26114224

Refining soil organic carbon stock estimates for China’s palustrine wetlands

NASA Astrophysics Data System (ADS)

Ma, Kun; Liu, Junguo; Zhang, Ying; Parry, Lauren E.; Holden, Joseph; Ciais, Philippe

2015-12-01

Palustrine wetlands (PWs) include all bogs, fens, swamps and marshes that are non-saline and which are not lakes or rivers. They therefore form a highly important group of wetlands which hold large carbon stocks. If these wetlands are not protected properly they could become a net carbon source in the future. Compilation of spatially explicit wetland databases, national inventory data and in situ measurement of soil organic carbon (SOC) could be useful to better quantify SOC and formulate long-term strategies for mitigating global climate change. In this study, a synergistic mapping approach was used to create a hybrid map for PWs for China and to estimate their SOC content. Total SOC storage in PWs was estimated to be 4.3 ± 1.4 Pg C, with a SOC density of 31.17 (±10.55) kg C m-2 in the upper 1 m of the soil layer. This carbon stock is concentrated in Northeast China (49%) and the Qinghai-Tibet Plateau (41%). Given the large pool of carbon stored in PWs compared to other soil types, we suggest that urgent monitoring programmes on SOC should be established in regions with very few datasets, but where PWs appear to be common such as the Tibet region and Northwest China.

Intense uplift of the Qinghai-Tibetan Plateau triggered rapid diversification of Phyllolobium (Leguminosae) in the Late Cenozoic

Treesearch

Ming-Li Zhang; Yun Kang; Yang Zhong; Stewart C. Sanderson

2012-01-01

Phyllolobium, a recently established genus from subgenus Pogonophace of Astragalus, contains about 20 species and four sections, mostly endemic to the Qinghai-Tibetan Plateau (QTP). The uplift of the QTP undoubtedly affected organismic evolution in the region, but further molecular dating in a phylogenetic context is required to test whether diversification is linked...

Lake Qinghai Drilling Project: Evolution History of Lake Qinghai and East Asian Monsoon Changes since the Late Miocene

NASA Astrophysics Data System (ADS)

An, Z.; Colman, S.

2007-12-01

As a closed continental lake on the north-east margin of the Tibetan Plateau, Lake Qinghai is sensitive to climate variations as well as the environmental effects of Plateau growth/uplift. Supported by Chinese funding agencies and ICDP, onshore and offshore lake cores were drilled in 2005. We compare our preliminary chronostratigraphic, sedimentologic, and geochemical results with climatic records from the Loess Plateau, South China Sea, Arctic and global oceans, and we discuss the evolution of Lake Qinghai at different time scales since the late Miocene. Lake Qinghai is shown to have intimate linkages with the warm/moist East Asian summer monsoon, the cold/dry East Asian winter monsoon, and the growth/uplift of the Tibetan Plateau. Magnetostratigraphic studies of the onshore drill cores indicate that thick greenish clays were deposited during Late Miocene, suggesting the initial formation of the Qinghai Lake basin. Consistent with proxies from the Loess Plateau and the South China Sea, they imply summer-monsoon strengthening and inland intrusion. These changes may be related to a growth event of the Tibetan Plateau at 10-8 Ma, which led to the uplift of Qinghai Nanshan, formation of faulted lake basins, and enhanced summer monsoon circulation. From 6 to 4.6Ma eolian red clays in the core indicate lake basin dessication, as Loess Plateau dust flux increased with the strengthening of the winter monsoon and coincident with intense Arctic ice rafting at 6-5 Ma. From 4.6 to 3.5 Ma thick greenish clays were deposited as modern Lake Qinghai formed. Significantly increased fluxes of TOC, C/N and total sediment might be related to uplift of Qinghai Nanshan and basin subsidence at that time, and they are coeval with the increasing strength of East Asian monsoon during early Pliocene. At 3.5-2.6 Ma, continued strengthening of the East Asian summer monsoon, inland aridification, and increases in global ice volume suggest another growth event of the Tibetan Plateau. Shallow-water silty clays were deposited in the lake basin at this time. Since 2.6 Ma, deposition in the basin was characterized by shallow-water silty clays, intercalated with layers of loess- like material, eolian sand, gravel, and sand, indicating multiple lake expansion/dessication cycles, presumably at orbital frequencies, reflecting multiple migrations of the East Asian summer monsoon front driven by solar radiation and global ice volume changes over this region. Several previous studies of cores as much as 7m long from the depositional basins of Lake Qinghai have documented monsoon climate and environmental changes at the lake from the deglacial period through the Holocene, which are generally consistent with northern Hemisphere summer insolation and its seasonality changes. A wide variety of proxies have been used, and some cores have been studied at very high temporal resolution, especially for the last several hundred years. Results suggest that solar activity influences decadal regional temperatures, and that it is the East Asian summer monsoon as opposed to the Indian summer monsoon that acts as the dominate moisture source at the decadal scale within the local region. Offshore GLAD800 drill cores obtained in 2005 sampled fine-grained sediments before encountering thick units of sand. The fine-grained sections are 2-3 times longer than previous cores from similar sites. Paleolimnological proxy studies are underway on these cores to extend the young part of the paleoenvironmental record back to significantly before the last glacial maximum.

[Resources of survey in rare and endangered medicinal plant Sinopodophyllum emodi].

PubMed

Zhao, Jifeng; Liu, Xiang; Wang, Changhua; Zhang, Zhiwei; Qin, Songyun; Zhong, Guoyue

2011-05-01

The resource of Sinopodophyllum emodi in Tibet, Qinghai, Gansu, Sichuan and Yunnan province were surveyed by the ways of documents, interview, quadrat and market investigation. The results indicated that S. emodi were mainly distributed in central part from Taibai Shan of Shanxi province along the middle and high mountain on either side of Hengduan mountain which from north to south and in Tibetan plateau of China, the suitable eco-environment of S. emodi was dominated by valleys, wet forests and low bush-woods vegetation which comparatively dry on plateau with the altitude focused on 1 5004 500 meters, and the distribution density of simple alpine meadow was relatively lower. Illumination, water, soil, temperature and altitude had significant influences on the growth, distribution and reserves of S. emodi from different angles. In recent years, there was sharp increase of market requirement in Xiaoyelian (fruit) which were used in Tibetan medicine and the underground part which was used for the extraction of podophyllotoxin, excess collection of the underground part was the primary cause of the rapid decreasing resource of S. emodi. It is suggested that the management of rational collection should be strengthen and the development of culturing and production should be meanwhile accelerated.

Surface Deformation and Lower Crustal Flow in Eastern Tibet

PubMed

Royden; Burchfiel; King; Wang; Chen; Shen; Liu

1997-05-02

Field observations and satellite geodesy indicate that little crustal shortening has occurred along the central to southern margin of the eastern Tibetan plateau since about 4 million years ago. Instead, central eastern Tibet has been nearly stationary relative to southeastern China, southeastern Tibet has rotated clockwise without major crustal shortening, and the crust along portions of the eastern plateau margin has been extended. Modeling suggests that these phenomena are the result of continental convergence where the lower crust is so weak that upper crustal deformation is decoupled from the motion of the underlying mantle. This model also predicts east-west extension on the high plateau without convective removal of Tibetan lithosphere and without eastward movement of the crust east of the plateau.

Mapping risk of plague in Qinghai-Tibetan Plateau, China.

PubMed

Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

2014-07-10

Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

Actinomyces gaoshouyii sp. nov., isolated from plateau pika (Ochotona curzoniae).

PubMed

Meng, Xiangli; Wang, Yiting; Lu, Shan; Lai, Xin-He; Jin, Dong; Yang, Jing; Xu, Jianguo

2017-09-01

Two strains (pika_113T and pika_114) of a previously undescribed Actinomyces-like bacterium were recovered from the intestinal contents of plateau pika (Ochotona curzoniae) on the Tibet-Qinghai Plateau, China. Results from biochemical characterization indicated that the two strains were phenotypically homogeneous and distinct from other previously described species of the genus Actinomyces. Based on the comparison of 16S rRNA gene sequences and genome analysis, the bacteria were determined to be a hitherto unknown subline within the genus Actinomyces, being most closely related to type strains of Actinomyces denticolens and Actinomyces timonensis with a respective 97.2 and 97.1 % similarity in their 16S rRNA gene sequences. Phylogenetic analyses confirmed that pika_113T was well separated from any other recognized species of the genus Actinomyces and within the cluster with A. denticolens and A. timonensis. The genome of strain pika_113T displayed less than 42 % relatedness in DNA-DNA hybridization with all the available genomes of existing species of the genus Actinomyces in the NCBI database. Collectively, based on the phenotypic characteristics and phylogenetic analyses results, we propose the novel isolates as representatives of Actinomyces gaoshouyii sp. nov. The type strain of Actinomyces gaoshouyii is pika_113T (=CGMCC 4.7372T=DSM 104049T), with a genomic DNA G+C content of 71 mol%.

Comparison of characteristics of chronic kidney diseases between Tibet plateau and plain areas

PubMed Central

Zhou, Yan; Deng, Yong-Ming; Li, Chuan; Gong, Yun-Bing; Mao, Zhi-Guo; Wu, Jun; Li, Su-Zhi; Liu, Zhi-Hong; Tang, Zheng

2014-01-01

Background: The purpose of the current study was to investigate the pathological characteristics of chronic kidney diseases in the Tibet plateau and the plain. Methods: 77 cases from the Tibet plateau and 154 cases from the plain of renal biopsied patients with chronic kidney diseases were compared in a randomized, and parallel controlled manner. Pathological characteristics were defined according to the standards of WHO and associated classifications. Results: The ration of sex was shown that most of patients in the plateau region were female, whereas those in the plain were male. The characteristics of pathological types were shown that the patients in the plateau region were primarily minimal change disease, but IgA nephropathy was rare; meanwhile, the proportional lupus nephritis (LN) ratio of the secondary glomerulonephritis in the plateau region was significantly lower than those in the plain region. Conclusions: The current data demonstrated that the most common kidney disease in the Tibet Plateau region is still the primary glomerulonephritis as the same as those in the plain region. However, the primary glomerular disease in the plateau region is minimal change disease, and the most common clinical manifestations are the nephrotic syndrome. The IgA nephropathy in the plain is the most frequent disease. In terms of the secondary renal diseases, Henoch-Schnolein purpura nephritis are dominated in the plateau region, whereas LN-based diseases are frequently found in the plain. There is a statistical significance existed between those two groups. PMID:25337266

Prehistoric Human Adaptation to Tibetan Plateau Environment indicated by 151 site in the Qinghai Lake Basin

NASA Astrophysics Data System (ADS)

Zhang, Dongju; Dong, Guanghui; Wang, Qianqian; Ren, Xiaoyan; Chen, Fahu

2017-04-01

Current study indicates that Northeastern Tibetan Plateau (NETP) is one of the first widely occupied places by prehistory people on the Tibetan Plateau, which makes NETP very important to understand the human history on the plateau and human adaptation to high elevation environment. Hence, 151 site, a paleo- to Epi-Paleolithic site in the Qinghai Lake basin on NETP, is chosen to excavate. Thousands pieces of animal bones, hundreds pieces of stone artifacts and several possible hearths were unearthed and obtained during two excavation seasons. Carefully redating of the site shows that it was first occupied shortly around 15 ka BP, then reoccupied from 9000-6000 a BP more intensely. Preliminary study of the site suggest that the first appearance of human in Qinghai Lake basin is closely related to the amelioration of the Last Deglaciation and the prevalence of microlithic technology in North China, which may enlighten the study of early human migration on to whole plateau; however, the latter more intense human occupation in 151 site is not only closely related to the warm and stable early-mid Holocene climate but also provoked by early millet agriculture in neighbor low-elevation Loess plateau.

Gravity anomaly and crustal structure characteristics in North-South Seismic Belt of China

NASA Astrophysics Data System (ADS)

Shen, Chongyang; Xuan, Songtbai; Yang, Guangliang; Wu, Guiju

2017-04-01

The North-South Seismic Belt (NSSB) is the binary system boundary what is formed by the western Indian plate subduction pushing and the eastern west Pacific asthenosphere rising, and it is one of the three major seismic belts (Tianshan, Taiwan and NSSB) and mainly located between E102°and E107°. And it is mainly composed of topographic gradient zones, faults, cenozoic basins and strong earthquake zones, which form two distinct parts of tectonic and physical features in the west and east. The research results of geophysical and deep tectonic setting in the NSSB show that it is not only a gravity anomaly gradient zone, it is but also a belt of crustal thickness increasing sharply westward of abrupt change. Seismic tomography results show that the anomaly zone is deeper than hundreds of kilometers in the NSSB, and the composition and structure of the crust are more complex. We deployed multiple Gravity and GNSS synchronous detection profiles in the NSSB, and these profiles crossed the mainly faults structure and got thousands of points data. In the research, source analysis, density structure inversion, residual gravity related imaging and normalized full gradient methods were used, and analyzed gravity field, density and their structure features in different positions, finally obtained the crustal density structure section characteristics and depth structure differences. The research results showed that the gravity Bouguer anomaly is similar to the existing large scale result. The Bouguer anomaly is rising significantly from west to east, its trend variation coincides well with the trend change of Moho depth, which is agreeing with the material flows to the peripheral situation of the Tibetan plateau. The obvious difference changes of the residual anomaly is relative to the boundary of structure or main tectonics, it's also connected with the stop degree of the eurasian plate when the material migrates around. The density structure of the gravity profiles mainly reflects basic frame work of the regional crust structure. The earth's crust basically present three layer structure, nearly horizontally distributes, undulation of Moho is obvious, which is consistent with the results of seismic sounding and seismic array detection; in the local area, there are lower density layer zonal distribution in the earth's crust what accelerates the lateral movement in up and middle crust; when the substance of the Tibetan plateau spreads around, the integrity in up and middle crust is well, and it is basically a coupling movement together; in the lower crust, the thickness of the Tibetan plateau is outward gradually thinning, there is decoupling phenomenon in crust-mantle; The results of the gravity and the crustal density structure show that the research area can be divided into several part such as Qinghai-Tibet Plateau, Sichuan-Yunnan block, Ordos block and Alxa block, the transitional zones of the Qinghai-Tibet Plateau and Sichuan basin, and Alxa and Ordos are complex, and Moho slope is bigger, where is the part of strong tectonic activity and strong earthquakes occur easily. The research is of great significance for study the crustal deep structure, geodynamic evolution process and environment of earthquake gestation of the NSSB region.

[The pathogenic ecology research on plague in Qinghai plateau].

PubMed

Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun

2013-12-01

To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial distribution regularities of plague epidemic and the pathogens characteristics, meanwhile the polymorphism of plague ecological geographic landscape leds to the complexity of Yersinia pestis' genotype.

MLVA and MLST typing of Brucella from Qinghai, China.

PubMed

Ma, Jun-Ying; Wang, Hu; Zhang, Xue-Fei; Xu, Li-Qing; Hu, Gui-Ying; Jiang, Hai; Zhao, Fang; Zhao, Hong-Yan; Piao, Dong-Ri; Qin, Yu-Min; Cui, Bu-Yun; Lin, Gong-Hua

2016-04-13

The Qinghai-Tibet Plateau (QTP) of China is an extensive pastoral and semi-pastoral area, and because of poverty and bad hygiene conditions, Brucella is highly prevalent in this region. In order to adequately prevent this disease in the QTP region it is important to determine the identity of Brucella species that caused the infection. A total of 65 Brucella isolates were obtained from human, livestock and wild animals in Qinghai, a Chinese province in east of the QTP. Two molecular typing methods, MLVA (multi-locus variable-number tandem-repeat analysis) and MLST (multi locus sequence typing) were used to identify the species and genotypes of these isolates. Both MLVA and MLST typing methods classified the 65 isolates into three species, B. melitensis, B. abortus and B. suis, which included 60, 4 and 1 isolates respectively. The MLVA method uniquely detected 34 (Bm01 ~ Bm34), 3 (Ba01 ~ Ba03), and 1 (Bs01) MLVA-16 genotypes for B. melitensis, B. abortus and B. suis, respectively. However, none of these genotypes exactly matched any of the genotypes in the Brucella2012 MLVA database. The MLST method identified five known ST types: ST7 and ST8 (B. melitensis), ST2 and ST5 (B. abortus), and ST14 (B. suis). We also detected a strain with a mutant type (3-2-3-2-?-5-3-8-2) of ST8 (3-2-3-2-1-5-3-8-2). Extensive genotype-sharing events could be observed among isolates from different host species. There were at least three Brucella (B. melitensis, B. abortus and B. suis) species in Qinghai, of which B. melitensis was the predominant species in the area examined. The Brucella population in Qinghai was very different from other regions of the world, possibly owing to the unique geographical characteristics such as extremely high altitude in QTP. There were extensive genotype-sharing events between isolates obtained from humans and other animals. Yaks, sheep and blue sheep were important zoonotic reservoirs of brucellosis causing species found in humans.

Response of greenhouse gas emissions from three types of wetland soils to simulated temperature change on the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, Yi; Liu, Guihua; Xiong, Ziqian; Liu, Wenzhi

2017-12-01

Wetlands emit a large quantity of greenhouse gases into the atmosphere and contribute significantly to global warming. The Qinghai-Tibetan Plateau, known as the ;Third Pole; of the earth, contains abundant and diverse wetlands. Due to increasing human-induced pressures such as reclamation, overgrazing and climate change, many plateau wetlands have been degraded or destroyed. Until now, the response of soil greenhouse gas emissions to extreme summer temperatures in the plateau wetlands remains unknown. In this study, we collected 36 soil samples from riverine, lacustrine and palustrine wetlands on the Qinghai-Tibetan Plateau. We compared the carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions from soils incubated aerobically at 7, 12, and 19 °C. The results showed that the emissions of CH4 and N2O but not CO2 were significantly affected by the simulated temperature change. The N2O emission rate was considerably higher in palustrine wetlands compared with lacustrine and riverine wetlands. However, the CO2 and CH4 emissions did not differ significantly among the three wetland types. The ratio of CO2 to CH4 production increased with increasing incubation temperatures. The global warming potential of greenhouse gases at 19 °C was approximately 1.18 and 2.12 times greater than that at 12 and 7 °C, respectively. Our findings suggest that temperature change has a strong effect on soil greenhouse gas emissions and global warming potential of wetlands on the Qinghai-Tibetan Plateau, especially palustrine wetlands. Therefore, targeted strategies should be developed to mitigate the potential impacts of climate warming on the plateau.

Integrated assessment on the vulnerability of animal husbandry to snow disasters under climate change in the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wei, Yanqiang; Wang, Shijin; Fang, Yiping; Nawaz, Zain

2017-10-01

Animal husbandry is a dominant and traditional source of livelihood and income in the Qinghai-Tibetan Plateau. The Qinghai-Tibetan Plateau is the third largest snow covered area in China and is one of the main snow disaster regions in the world. It is thus imperative to urgently address the issue of vulnerability of the animal husbandry sector to snow disasters for disaster mitigation and adaptation under growing risk of these disasters as a result of future climate change. However, there is very few literature reported on the vulnerability of animal husbandry in the Qinghai-Tibetan Plateau. This assessment aims at identifying vulnerability of animal husbandry at spatial scale and to identify the reasons for vulnerability for adaptive planning and disaster mitigation. First, historical snow disaster characteristics have been analyzed and used for the spatial weight for vulnerability assessment. Second, indicator-based vulnerability assessment model and indicator system have been established. We combined risk of snow hazard, sensitivity of livestock to disaster, physical exposure to disaster, and community capacity to adapt to snow disaster in an integrated vulnerability index. Lastly, vulnerability of animal husbandry to snow disaster on the Qinghai-Tibetan Plateau has been evaluated. Results indicate that high vulnerabilities are mainly concentrated in the eastern and central plateau and that vulnerability decreases gradually from the east to the west. Due to global warming, the vulnerability trend has eased to some extent during the last few decades. High livestock density exposure to blizzard-prone regions and shortages of livestock barn and forage are the main reasons of high vulnerability. The conclusion emphasizes the important role of the local government and community to help local pastoralists for reducing vulnerability to snow disaster and frozen hazard. The approaches presented in this paper can be used for snow disaster mitigation, resilience enhancement and effectively reducing vulnerability to natural hazards in other regions.

The Qinghai-Tibetan plateau: how high do Tibetans live?

PubMed

Wu, T

2001-01-01

A lower incidence of chronic mountain sickness (CMS) has apparently been observed in Tibetans in comparison to Andeans of South America. In the past, the hypothesis of "geographic differences" has been constructed to explain these population differences. In order to assess the importance of this hypothesis in the development of CMS, this article will first review the geographic factors of the Qinghai-Tibetan plateau where Tibetans live. The plateau is bounded by the Himalayas in the southwest and the Kunlun and Aljin mountains in the northeast. It towers over southwestern China at an average elevation of 4000 m above sea level and is known as "the roof of the world." Covering more than 2.5 million km(2), the Qinghai-Tibetan plateau is the highest and largest plateau in the world. The plateau has a highland continental climate and a very complex topography with great variations. Second, at what altitude do Tibetans live? In 1990 it was estimated that 4,594,188 Tibetans live on the plateau, with 53% living at an altitude over 3500 m. Fairly large numbers (about 600,000) live at an altitude exceeding 4500 m in the Chantong-Qingnan area. People of Tibetan ethnic descent are lifelong high-altitude residents and cannot easily move to higher or lower elevations. Over 90% of the population are engaged in farming and herding. The upper altitude limit of crops is around 4500 m, while the nomads reside above 4800 m and 5500 m. Recently, mining activities in the plateau have sustained a part of the population that lives permanently at altitudes between 3700 and 6000 m. Therefore, the Tibetans living in the Qinghai-Tibetan plateau live at an altitude as high as the Andeans in South America. Thus the apparently low incidence of CMS in Tibetans cannot be ascribed to "geographic differences." We propose that the genetic adaptation to hypoxia that has occurred in Tibetans is of importance in CMS.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in 1-2-month-old highland yaks in Qinghai Province, China.

PubMed

Wang, Geping; Wang, Guanghua; Li, Xiuping; Zhang, Xueyong; Karanis, Gabriele; Jian, Yingna; Ma, Liqing; Karanis, Panagiotis

2018-06-01

Cryptosporidium and Giardia are ubiquitous parasites that infect humans and animals. Few reports are available on the prevalence of these two protozoan parasites in yaks (Bos grunniens). In this study, 344 faecal samples were collected from yaks with diarrhoea in the Chenduo and Nangqian counties of Qinghai Province, China. Cryptosporidium spp. and Giardia duodenalis were detected by light and immunofluorescence microscopy and nested PCR (nPCR). Fifteen samples were positive (4.5%) by Kinyoun staining, 40 (11.6%) samples were positive by immunofluorescence test (IFT), and 39 (11.3%) samples were positive by nPCR for Cryptosporidium spp., Cryptosporidium bovis (11/39, 28.2%) was the most prevalent species, followed by C. ryanae (6/39, 15.4%), C. andersoni (5/39, 12.8%), C. struthionis (5/39, 12.8%), C. parvum (5/39, 12.8%), C. hominis (4/39, 10.3%) and C. canis (3/39, 7.7%). Thirteen out of 344 (3.8%) samples were positive for Giardia by simple microscopy, 20 (5.8%) by IFT and 18 samples (5.2%) yak faecal samples were Giardia positive by nPCR. Two G. duodenalis assemblages (B, E) were detected in this study. Nine positive samples for G. duodenalis assemblage E were from the towns of Xiewu (8/9, 4.9%) and Xiangda (1/9, 1.3%), and nine positive samples (9/9, 8.5%) for G. duodenalis assemblage B were from the town of Zhenqin. This report provides information about infection with Cryptosporidium species and G. duodenalis assemblages in domesticated 1-2-month-old highland yaks living in the Qinghai-Tibet Plateau region of China.

Observation and analysis of electrical structure change and diversity in thunderstorms on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, Yajun; Zhang, Guangshu; Wang, Yanhui; Wu, Bin; Li, Jing

2017-09-01

A comprehensive observation on thunderstorms was conducted in the Qinghai area by using a very high frequency three-dimensional lightning mapping system and Doppler radar. The spatio-temporal evolution of the charge structure of the isolated thunderstorm was analyzed according to the developing process of thunderstorm, and the reasons for the change in charge structure diversity were studied. During the initial developing and mature stages of the thunderstorm, the charge structure was a steady negative dipole polarity, i.e., the negative charge region was above the positive charge region. Furthermore, the total number of flashes was lower during these two stages. During the thunderstorm's dissipation stage, the charge structure was varied and complicated, with a positive dipole, negative dipole, and a tripole charge structure changing and coexisting during this stage. This charge structure diversity was primarily caused by the collision and merging of two local thunderstorm cells, leading to a charge rearrangement and distribution and the formation of a new charge structure. The frequency of the negative cloud-to-ground and intracloud flashes increased sharply in the dissipation stage, reaching a maximum value. The increase in frequency of negative cloud-to-ground was mainly caused by the lower positive charge weakening during the dissipation stage. In addition, the relationship between charging regions and temperature layers was analyzed by combining sounding temperature data with the theory of a non-inductive charging mechanism.

Detours in long-distance migration across the Qinghai-Tibetan Plateau: individual consistency and habitat associations.

PubMed

Liu, Dongping; Zhang, Guogang; Jiang, Hongxing; Lu, Jun

2018-01-01

Migratory birds often follow detours when confronted with ecological barriers, and understanding the extent and the underlying drivers of such detours can provide important insights into the associated cost to the annual energy budget and the migration strategies. The Qinghai-Tibetan Plateau is the most daunting geographical barrier for migratory birds because the partial pressure of oxygen is dramatically reduced and flight costs greatly increase. We analyzed the repeated migration detours and habitat associations of four Pallas's Gulls Larus ichthyaetus across the Qinghai-Tibetan Plateau over 22 migration seasons. Gulls exhibited notable detours, with the maximum distance being more than double that of the expected shortest route, that extended rather than reduced the passage across the plateau. The extent of longitudinal detours significantly increased with latitude, and detours were longer in autumn than in spring. Compared with the expected shortest routes, proximity to water bodies increased along autumn migration routes, but detour-habitat associations were weak along spring migration routes. Thus, habitat availability was likely one, but not the only, factor shaping the extent of detours, and migration routes were determined by different mechanisms between seasons. Significant between-individual variation but high individual consistency in migration timing and routes were revealed in both seasons, indicating a stronger influence of endogenous schedules than local environmental conditions. Gulls may benefit from repeated use of familiar routes and stopover sites, which may be particularly significant in the challenging environment of the Qinghai-Tibetan Plateau.

Oblique stepwise rise and growth of the Tibet plateau.

PubMed

Tapponnier, P; Zhiqin, X; Roger, F; Meyer, B; Arnaud, N; Wittlinger, G; Jingsui, Y

2001-11-23

Two end member models of how the high elevations in Tibet formed are (i) continuous thickening and widespread viscous flow of the crust and mantle of the entire plateau and (ii) time-dependent, localized shear between coherent lithospheric blocks. Recent studies of Cenozoic deformation, magmatism, and seismic structure lend support to the latter. Since India collided with Asia approximately 55 million years ago, the rise of the high Tibetan plateau likely occurred in three main steps, by successive growth and uplift of 300- to 500-kilometer-wide crustal thrust-wedges. The crust thickened, while the mantle, decoupled beneath gently dipping shear zones, did not. Sediment infilling, bathtub-like, of dammed intermontane basins formed flat high plains at each step. The existence of magmatic belts younging northward implies that slabs of Asian mantle subducted one after another under ranges north of the Himalayas. Subduction was oblique and accompanied by extrusion along the left lateral strike-slip faults that slice Tibet's east side. These mechanisms, akin to plate tectonics hidden by thickening crust, with slip-partitioning, account for the dominant growth of the Tibet Plateau toward the east and northeast.

Morphological Observations and Fatty Acid Composition of Indoor-Cultivated Cordyceps sinensis at a High-Altitude Laboratory on Sejila Mountain, Tibet

PubMed Central

Guo, Lian-Xian; Xu, Xiao-Ming; Liang, Fu-Rui; Yuan, Jian-Ping; Peng, Juan; Wu, Chou-Fei; Wang, Jiang-Hai

2015-01-01

Cordyceps sinensis, a caterpillar entomopathogenic fungus-host larva complex, is a rare medicinal herb found in the Qinghai-Tibetan Plateau and its surrounding high-altitude areas. The alternation of generations in the life cycle, whatever the fungus or its host insect, requires special growth conditions. However, it is difficult to simulate the growth conditions of C. sinensis, which hinders its artificial cultivation. In this work, the life cycle from the host larva to C. sinensis was observed in an indoor-cultivation laboratory at 4,200 m a.s.l. on Sejila Mountain, Tibet. Comparative examinations between indoor-cultivated and wild C. sinensis demonstrated that the indoor-cultivated C. sinensis preferred to germinate multiple long, slim stromata at diverse positions on dead larvae, including but not limited to their heads. Their fatty acid composition shows a significant difference in the levels of polyunsaturated fatty acids (PUFAs). In indoor-cultivated C. sinensis, PUFAs constituted 24.59% and 49.43%, respectively, of neutral and polar lipids; meanwhile, in wild C. sinensis, PUFAs represented 34.34% and 61.25% of neutral and polar lipids, respectively. These observations and fatty acid data suggest that environmental factors, particularly temperature, soil pressure and light intensity, strongly affect the growth of C. sinensis. Our new findings may provide important information for improving techniques for the large-scale artificial cultivation of C. sinensis. PMID:25938484

Morphological Observations and Fatty Acid Composition of Indoor-Cultivated Cordyceps sinensis at a High-Altitude Laboratory on Sejila Mountain, Tibet.

PubMed

Guo, Lian-Xian; Xu, Xiao-Ming; Liang, Fu-Rui; Yuan, Jian-Ping; Peng, Juan; Wu, Chou-Fei; Wang, Jiang-Hai

2015-01-01

Cordyceps sinensis, a caterpillar entomopathogenic fungus-host larva complex, is a rare medicinal herb found in the Qinghai-Tibetan Plateau and its surrounding high-altitude areas. The alternation of generations in the life cycle, whatever the fungus or its host insect, requires special growth conditions. However, it is difficult to simulate the growth conditions of C. sinensis, which hinders its artificial cultivation. In this work, the life cycle from the host larva to C. sinensis was observed in an indoor-cultivation laboratory at 4,200 m a.s.l. on Sejila Mountain, Tibet. Comparative examinations between indoor-cultivated and wild C. sinensis demonstrated that the indoor-cultivated C. sinensis preferred to germinate multiple long, slim stromata at diverse positions on dead larvae, including but not limited to their heads. Their fatty acid composition shows a significant difference in the levels of polyunsaturated fatty acids (PUFAs). In indoor-cultivated C. sinensis, PUFAs constituted 24.59% and 49.43%, respectively, of neutral and polar lipids; meanwhile, in wild C. sinensis, PUFAs represented 34.34% and 61.25% of neutral and polar lipids, respectively. These observations and fatty acid data suggest that environmental factors, particularly temperature, soil pressure and light intensity, strongly affect the growth of C. sinensis. Our new findings may provide important information for improving techniques for the large-scale artificial cultivation of C. sinensis.

Genetic evidence from mitochondrial DNA corroborates the origin of Tibetan chickens.

PubMed

Zhang, Long; Zhang, Pu; Li, Qingqing; Gaur, Uma; Liu, Yiping; Zhu, Qing; Zhao, Xiaoling; Wang, Yan; Yin, Huadong; Hu, Yaodong; Liu, Aiping; Li, Diyan

2017-01-01

Chicken is the most common poultry species and is important to human societies. Tibetan chicken (Gallus gallus domesticus) is a breed endemic to China that is distributed mainly on the Qinghai-Tibet Plateau. However, its origin has not been well characterized. In the present study, we sequenced partial mitochondrial DNA (mtDNA) control region of 239 and 283 samples from Tibetan and Sichuan indigenous chickens, respectively. Incorporating 1091 published sequences, we constructed the matrilineal genealogy of Tibetan chickens to further document their domestication history. We found that the genetic structure of the mtDNA haplotypes of Tibetan chickens are dominated by seven major haplogroups (A-G). In addition, phylogenetic and network analyses showed that Tibetan chickens are not distinguishable from the indigenous chickens in surrounding areas. Furthermore, some clades of Tibetan chickens may have originated from game fowls. In summary, our results collectively indicated that Tibetan chickens may have diverged from indigenous chickens in the adjacent regions and hybridized with various chickens.

First report of Echinococcus shiquicus in dogs from eastern Qinghai-Tibet plateau region, China.

PubMed

Boufana, Belgees; Qiu, Jiamin; Chen, Xinwang; Budke, Christine M; Campos-Ponce, Maiza; Craig, Philip S

2013-07-01

Echinococcus shiquicus was discovered in foxes and pika wildlife hosts in Sichuan Province, China in 2005. Faecal samples from dogs collected in a previous echinococcosis purgation survey from Shiqu County, Ganzi Tibetan Autonomous Prefecture (Sichuan) were screened by coproPCR to investigate the possible occurrence of E. shiquicus. In addition, coproDNA extracted from 8 necropsied Tibetan foxes (Vulpes ferrilata), the natural host of E. shiquicus, were also included. Thirty (6/20) percent of faecal samples from dogs were positive for E. shiquicus DNA after PCR amplification of a fragment within the ND1 mitochondrial gene. Echinococcus shiquicus was confirmed by sequencing in four dogs and 3 of the 6 dogs were concurrently infected with E. multilocularis. These were also verified by sequencing. Faecal samples from two Tibetan foxes were shown by PCR to harbour both E. multilocularis and E. shiquicus DNA. One of these dual E. multilocularis and E. shiquicus infections in a Tibetan fox was confirmed by sequencing. Copyright © 2013 Elsevier B.V. All rights reserved.

Impacts of the thawing-freezing process on runoff generation in the Sources Area of the Yellow River on the northeastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Wu, Xiaoling; Xiang, Xiaohua; Qiu, Chao; Li, Li

2018-06-01

In cold regions, precipitation, air temperature and snow cover significantly influence soil water, heat transfer, the freezing-thawing processes of the active soil layer, and runoff generation. Hydrological regimes of the world's major rivers in cold regions have changed remarkably since the 1960s, but the mechanisms underlying the changes have not yet been fully understood. Using the basic physical processes for water and heat balances and transfers in snow covered soil, a water-heat coupling model for snow cover and its underlying soil layers was established. We found that freezing-thawing processes can affect the thickness of the active layer, storage capacity for liquid water, and subsequent surface runoffs. Based on calculations of thawing-freezing processes, we investigated hydrological processes at Qumalai. The results show that the water-heat coupling model can be used in this region to provide an understanding of the local movement of hydrological regimes.

Genetic evidence from mitochondrial DNA corroborates the origin of Tibetan chickens

PubMed Central

Zhu, Qing; Zhao, Xiaoling; Wang, Yan; Yin, Huadong; Hu, Yaodong; Liu, Aiping; Li, Diyan

2017-01-01

Chicken is the most common poultry species and is important to human societies. Tibetan chicken (Gallus gallus domesticus) is a breed endemic to China that is distributed mainly on the Qinghai-Tibet Plateau. However, its origin has not been well characterized. In the present study, we sequenced partial mitochondrial DNA (mtDNA) control region of 239 and 283 samples from Tibetan and Sichuan indigenous chickens, respectively. Incorporating 1091 published sequences, we constructed the matrilineal genealogy of Tibetan chickens to further document their domestication history. We found that the genetic structure of the mtDNA haplotypes of Tibetan chickens are dominated by seven major haplogroups (A-G). In addition, phylogenetic and network analyses showed that Tibetan chickens are not distinguishable from the indigenous chickens in surrounding areas. Furthermore, some clades of Tibetan chickens may have originated from game fowls. In summary, our results collectively indicated that Tibetan chickens may have diverged from indigenous chickens in the adjacent regions and hybridized with various chickens. PMID:28241078

Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau

PubMed Central

Li, Qiang; Wang, Xiaoming

2015-01-01

This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an “out of Tibet” hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an “into Tibet” scenario–earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet. PMID:26658457

Analysis of Soluble Proteins in Natural Cordyceps sinensis from Different Producing Areas by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis and Two-dimensional Electrophoresis

PubMed Central

Li, Chun-Hong; Zuo, Hua-Li; Zhang, Qian; Wang, Feng-Qin; Hu, Yuan-Jia; Qian, Zheng-Ming; Li, Wen-Jia; Xia, Zhi-Ning; Yang, Feng-Qing

2017-01-01

Background: As one of the bioactive components in Cordyceps sinensis (CS), proteins were rarely used as index components to study the correlation between the protein components and producing areas of natural CS. Objective: Protein components of 26 natural CS samples produced in Qinghai, Tibet, and Sichuan provinces were analyzed and compared to investigate the relationship among 26 different producing areas. Materials and Methods: Proteins from 26 different producing areas were extracted by Tris-HCl buffer with Triton X-100, and separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE). Results: The SDS-PAGE results indicated that the number of protein bands and optical density curves of proteins in 26 CS samples was a bit different. However, the 2-DE results showed that the numbers and abundance of protein spots in protein profiles of 26 samples were obviously different and showed certain association with producing areas. Conclusions: Based on the expression values of matched protein spots, 26 batches of CS samples can be divided into two main categories (Tibet and Qinghai) by hierarchical cluster analysis. SUMMARY The number of protein bands and optical density curves of proteins in 26 Cordyceps sinensis samples were a bit different on the sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profilesNumbers and abundance of protein spots in protein profiles of 26 samples were obvious different on two-dimensional electrophoresis mapsTwenty-six different producing areas of natural Cordyceps sinensis samples were divided into two main categories (Tibet and Qinghai) by Hierarchical cluster analysis based on the values of matched protein spots. Abbreviations Used: SDS-PAGE: Sodium dodecyl sulfate polyacrylamide gel electrophoresis, 2-DE: Two-dimensional electrophoresis, Cordyceps sinensis: CS, TCMs: Traditional Chinese medicines PMID:28250651

Analysis of Soluble Proteins in Natural Cordyceps sinensis from Different Producing Areas by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis and Two-dimensional Electrophoresis.

PubMed

Li, Chun-Hong; Zuo, Hua-Li; Zhang, Qian; Wang, Feng-Qin; Hu, Yuan-Jia; Qian, Zheng-Ming; Li, Wen-Jia; Xia, Zhi-Ning; Yang, Feng-Qing

2017-01-01

As one of the bioactive components in Cordyceps sinensis (CS), proteins were rarely used as index components to study the correlation between the protein components and producing areas of natural CS. Protein components of 26 natural CS samples produced in Qinghai, Tibet, and Sichuan provinces were analyzed and compared to investigate the relationship among 26 different producing areas. Proteins from 26 different producing areas were extracted by Tris-HCl buffer with Triton X-100, and separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE). The SDS-PAGE results indicated that the number of protein bands and optical density curves of proteins in 26 CS samples was a bit different. However, the 2-DE results showed that the numbers and abundance of protein spots in protein profiles of 26 samples were obviously different and showed certain association with producing areas. Based on the expression values of matched protein spots, 26 batches of CS samples can be divided into two main categories (Tibet and Qinghai) by hierarchical cluster analysis. The number of protein bands and optical density curves of proteins in 26 Cordyceps sinensis samples were a bit different on the sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profilesNumbers and abundance of protein spots in protein profiles of 26 samples were obvious different on two-dimensional electrophoresis mapsTwenty-six different producing areas of natural Cordyceps sinensis samples were divided into two main categories (Tibet and Qinghai) by Hierarchical cluster analysis based on the values of matched protein spots. Abbreviations Used : SDS-PAGE: Sodium dodecyl sulfate polyacrylamide gel electrophoresis, 2-DE: Two-dimensional electrophoresis, Cordyceps sinensis : CS, TCMs: Traditional Chinese medicines.

Simulations of wind erosion along the Qinghai-Tibet Railway in north-central Tibet

NASA Astrophysics Data System (ADS)

Jiang, Yingsha; Gao, Yanhong; Dong, Zhibao; Liu, Benli; Zhao, Lin

2018-06-01

Wind erosion along the Qinghai-Tibet Railway causes sand hazard and poses threats to the safety of trains and passengers. A coupled land-surface erosion model (Noah-MPWE) was developed to simulate the wind erosion along the railway. Comparison with the data from the 137Cs isotope analysis shows that this coupled model could simulate the mean erosion amount reasonably. The coupled model was then applied to eight sites along the railway to investigate the wind-erosion distribution and variations from 1979 to 2012. Factors affecting wind erosion spatially and temporally were assessed as well. Majority wind erosion occurs in the non-monsoon season from December to April of the next year except for the site located in desert. The region between Wudaoliang and Tanggula has higher wind erosion occurrences and soil lose amount because of higher frequency of strong wind and relatively lower soil moisture than other sites. Inter-annually, all sites present a significant decreasing trend of annual soil loss with an average rate of -0.18 kg m-2 a-1 in 1979-2012. Decreased frequency of strong wind, increased precipitation and soil moisture contribute to the reduction of wind erosion in 1979-2012. Snow cover duration and vegetation coverage also have great impact on the occurrence of wind erosion.

Geochronology, geochemical and Sr-Nd-Hf-Pb isotopic compositions of the granitoids in the Yemaquan orefield, East Kunlun orogenic belt, northern Qinghai-Tibet Plateau: Implications for magmatic fractional crystallization and sub-solidus hydrothermal alteration

NASA Astrophysics Data System (ADS)

Yin, Shuo; Ma, Changqian; Xu, Jiannan

2017-12-01

A general consensus has emerged that high field strength elements (HFSE) can mobile to some extent in a hydrothermal fluid. However, there are hot debates on whether sub-solidus hydrothermal alteration can lower the Nb/Ta ratio in evolved melts. In this study, we present petrography, geochronology and geochemistry of the barren and mineralized rocks in the Yemaquan skarn iron deposit, northern Qinghai-Tibet Plateau, to probe magmatic-hydrothermal transition. The barren rocks consist of diorites, granodiorites, granites and syenogranites, whereas the porphyritic granodiorites are associated with mineralization for an excellent consistency between the magmatic zircon U-Pb age (225 ± 2 Ma) and the hydrothermal phlogopite 40Ar-39Ar age (225 ± 1.5 Ma). The Sr-Nd-Hf-Pb isotopic data demonstrate that the Yemaquan granitoids are originated from a relatively homogenous enriched mantle with different degrees of crust contamination (assimilation fractional crystallization, AFC). Trace elements signatures indicate that the porphyritic granodiorites related to mineralization display amphibole crystallization for high water contents, whereas the barren granites have gone through biotite crystallization due to potassium enrichment by continuous upper crust contamination, both of which are responsible for their Nb/Ta ratios, respectively. Modeling results suggest that a basaltic melt with Nb/Ta ratio of 15.3 can reach a minimum Nb/Ta ratio of 12 in the producing granodioritic melt by amphibole fractional crystallization based on partition coefficients of Nb and Ta between amphibole and melts from previous experiments. This may explain the average Nb/Ta ratio (13.7) of the barren granodiorites, while it cannot account for the average Nb/Ta ratio (8.4) of the mineralized porphyritic granodiorites, and it is even lower than that of the granites (10.3) with biotite fractional crystallization. Exsolution of a magmatic-hydrothermal fluid is inevitable when a water saturated magma emplaced in shallow crust, leading to a transportation of certain chemical components from the magmatic melts to exsolved fluids. Because Nb seems more mobile than Ta in fluorine-bearing fluids, we contend that a preferentially transport Nb over Ta by sub-solidus hydrothermal alteration can further lower the Nb/Ta ratios of the mineralized porphyritic granodiorites, which may also result in a broad range of HFSE contents and their ratios in the altered porphyritic granodiorites formed in a post-magmatic process.

Rapid radiation and dispersal out of the Qinghai-Tibetan Plateau of an alpine plant lineage Rhodiola (Crassulaceae).

PubMed

Zhang, Jian-Qiang; Meng, Shi-Yong; Allen, Geraldine A; Wen, Jun; Rao, Guang-Yuan

2014-08-01

Rhodiola L. (Crassulaceae) is a mid-sized plant genus consisting of about 70 species, with most species distributed on the Qinghai-Tibetan Plateau (QTP) and the adjacent areas, and several species in north-east Asia, Europe, and North America. This study explored the origin and diversification history of Rhodiola and tested the biogeographic relationships between the QTP and other regions of the Northern Hemisphere. We sequenced the nuclear ribosomal internal transcribed spacers and eight plastid DNA fragments representing 55 species of Rhodiola, and reconstructed phylogenetic relationships with maximum parsimony, maximum likelihood and Bayesian inference. Several instances of incongruence between the nuclear and the plastid data sets were revealed, which can best be explained by reticulate evolution. Species of Rhodiola and Pseudosedum form a well-supported clade sister to Phedimus. Dating analysis suggested that the origin and diversification times of this group are largely correlated with the extensive uplifts of the Qinghai-Tibetan Plateau. Ancestral state reconstruction supports the hypothesis that Rhodiola originated on the QTP, and then dispersed to other regions of the Northern Hemisphere. Our findings highlight the importance of the uplifts of the Qinghai-Tibetan Plateau in promoting species diversification and the possible role of reticulate evolution in the diversification process. Our results also suggest the biogeographic significance of QTP as the source area in alpine plant evolution in the Northern Hemisphere. Copyright © 2014 Elsevier Inc. All rights reserved.

Distributions of glycerol dialkyl glycerol tetraethers in surface soils of Qinghai-Tibetan Plateau: implications of GDGT-based proxies in cold and dry regions

NASA Astrophysics Data System (ADS)

Ding, S.; Xu, Y.; Wang, Y.; He, Y.; Hou, J.; Chen, L.; He, J.-S.

2015-01-01

The methylation index of branched tetraethers (MBT) and cyclization ratio of branched tetraethers (CBT) based on the distribution of bacteria-derived branched glycerol dialkyl glycerol tetraethers (bGDGTs) are useful proxies for the reconstruction of continental paleotemperature and soil pH. Several calibrations of the MBT-CBT index have been proposed based on global and regional soils and lake sediments. However, little is known about the distribution and applicability of GDGTs proxies in the Qinghai-Tibet Plateau (QTP), a critical region of the global climate system. Here, we investigated 33 surface soils covering a large area of the QTP. Redundancy analysis showed that soil pH was the most important factor affecting GDGT distributions, followed by mean annual precipitation (MAP) and mean annual air temperature (MAT). The branched-isoprenoid tetraether (BIT) index, an indicator for estimation of soil organic matter in aquatic environments, varied from 0.48 to 1 and negatively correlated with soil pH (r2 = 0.38), suggesting that the BIT index should be used with caution in the QTP. A transfer function of the CBT index-soil pH was established to estimate paleo-soil pH in the QTP: pH = 8.33-1.43 × CBT (r2 = 0.80, RMSE = 0.27 pH unit). The local calibration of MBT-CBT index presented a weak, still significant correlation with MAT (r2 = 0.36) mainly owing to the additional influence of MAP (r2 = 0.50). Combining our data with previously reported GDGTs for Chinese soils resulted in a new calibration of MBT/CBT-MAT: MAT = 2.68+26.14 × MBT-3.37 × CBT (r2 = 0.73; RMSE = 4.2 °C, n = 164). The correlation coefficient and residual error of this new transfer function is comparable with global calibrations, suggesting that MBT-CBT paleotemperature proxy is still valid in the QTP.

Microbial diversity in hummock and hollow soils of three wetlands on the Qinghai-Tibetan Plateau revealed by 16S rRNA pyrosequencing.

PubMed

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world's highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1-10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem.

Microbial Diversity in Hummock and Hollow Soils of Three Wetlands on the Qinghai-Tibetan Plateau Revealed by 16S rRNA Pyrosequencing

PubMed Central

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G.

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world’s highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1–10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem. PMID:25078273

Tectonic stress pattern in the Chinese Mainland from the inversion of focal mechanism data

NASA Astrophysics Data System (ADS)

Wei, Ju; Weifeng, Sun; Xiaojing, Ma

2017-04-01

The tectonic stress pattern in the Chinese Mainland and kinematic models have been subjected to much debate. In the past several decades, several tectonic stress maps have been figured out; however, they generally suffer a poor time control. In the present study, 421 focal mechanism data up to January 2010 were compiled from the Global/Harvard CMT catalogue, and 396 of them were grouped into 23 distinct regions in function of geographic proximity. Reduced stress tensors were obtained from formal stress inversion for each region. The results indicated that, in the Chinese Mainland, the directions of maximum principal stress were ˜NE-SW-trending in the northeastern region, ˜NEE-SWW-trending in the North China region, ˜N-S-trending in western Xinjiang, southern Tibet and the southern Yunnan region, ˜NNE-SSW-trending in the northern Tibet and Qinghai region, ˜NW-SE-trending in Gansu region, and ˜E-W-trending in the western Sichuan region. The average tectonic stress regime was strike-slip faulting (SS) in the eastern Chinese Mainland and northern Tibet region, normal faulting (NF) in the southern Tibet, western Xinjiang and Yunnan region, and thrust faulting (TF) in most regions of Xinjiang, Qinghai and Gansu. The results of the present study combined with GPS velocities in the Chinese Mainland supported and could provide new insights into previous tectonic models (e.g., the extrusion model). From the perspective of tectonics, the mutual actions among the Eurasian plate, Pacific plate and Indian plate caused the present-day tectonic stress field in the Chinese Mainland.

[Evaluation of ecosystem resilience in the regions across Qinghai-Tibet railway based on GIS].

PubMed

Gao, Jiang-bo; Zhao, Zhi-qiang; Li, Shuang-cheng

2008-11-01

Based on GIS technique and the methods of mean-squared deviation weight decision and catastrophe progression, a more clear definition and associated evaluation for ecosystem resilience were given, with a case study in the regions across Qinghai-Tibet railway by using the indices of plant community coverage, species diversity, and biomass. It was shown that the areas with high ecosystem resilience were mainly located in the Qilian Mountain meadow grassland, Huangshui Valley needle-leaved and deciduous broad-leaved forest, and south Tanggula Mountain kobresia swamp meadow, while those with the lowest resilience were in the central part of Qaidam Basin, and the Kunlun Mountains. Most areas in the regions had higher or medium ecosystem resilience, with a trend of that in the south of Kunlun Mountains, the resilience in the north of the railway was lower, while in the east of Qaidam Basin (especially in the Qinghai Lake area), the resilience was lower in the south than in the north of the railway. Through the evaluation of ecosystem resilience, the key issues in the process of ecological resilience could be found, and corresponding effective measures would be pointed out to manage alpine ecosystems. Moreover, combining with the evaluation of vulnerability, scientific basis for regional development could be provided to avoid or mitigate the negative effects of human activities on eco-environment.

Tertiary structural evolution of the Gangdese thrust system southeastern Tibet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, An; Harrison, M.; Ryerson, F.J.

1994-09-10

Structural and thermochronological investigations of southern Tibet (Xizang) suggest that intracontinental thrusting has been the dominant cause for formation of thickened crust in the southernmost Tibetan plateau since late Oligocene. Two thrust systems are documented in this study: the north dipping Gangdese system (GTS) and the younger south dipping Renbu-Zedong system (RZT). West of Lhasa, the Gangdese thrust juxtaposes the Late Cretaceous forearc basin deposits of the Lhasa Block (the Xigaze Group) over the Tethyan sedimentary rocks of the Indian plate, whereas east of Lhasa, the fault juxtaposes the Late Cretaceous-Eocene, Andean-type arc (the Gangdese batholith) over Tethyan sedimentary rocks.more » Near Zedong, 150 km southeast of Lhasa, the Gangdese thrust is marked by a >200-m-thick mylonitic shear zone that consists of deformed granite and metasedimentary rocks. A major south dipping backthrust in the hanging wall of the Gangdese thrust puts the Xigaze Group over Tertiary conglomerates and the Gangdese plutonics north of Xigaze and west of Lhasa. A lower age bound for the Gangdese thrust of 18.3{+-}0.5 Ma is given by crosscutting relationships. The timing of slip on the Gangdese thrust is estimate to be 27-23 Ma from {sup 40}Ar/{sup 39}Ar thermochronology, and a displacement of at least 46{+-}9 km is indicated near Zedong. The age of the Gangdese thrust (GT) is consistent with an upper age limit of {approximately}24 Ma for the initiation of movement on the Main Central thrust. In places, the younger Renbu-Zedong fault is thrust over the trace of the GT, obscuring its exposure. The RZT appears to have been active at circa 18 Ma but had ceased movement by 8{+-}1 Ma. The suture between India and Asia has been complexely modified by development of the GTS, RZT, and, locally, strike-slip and normal fault systems. 64 refs., 14 figs., 2 tabs.« less

Magnetostratigraphy of the Neogene Chaka basin and its implications for mountain building processes in the north-eastern Tibetan Plateau

USGS Publications Warehouse

Zhang, H.-P.; Craddock, W.H.; Lease, Richard O.; Wang, W.-T.; Yuan, D.-Y.; Zhang, P.-Z.; Molnar, P.; Zheng, D.-W.; Zheng, W.-J.

2012-01-01

Magnetostratigraphy of sedimentary rock deposited in the Chaka basin (north-eastern Tibetan Plateau) indicates a late Miocene onset of basin formation and subsequent development of the adjacent Qinghai Nan Shan. Sedimentation in the basin initiated at ~11Ma. In the lower part of the basin fill, a coarsening-upward sequence starting at ~9Ma, as well as rapid sedimentation rates, and northward paleocurrents, are consistent with continued growth of the Ela Shan to the south. In the upper section, several lines of evidence suggest that thrust faulting and topographic development of the Qinghai Nan Shan began at ~6.1Ma. Paleocurrent indicators, preserved in the basin in the proximal footwall of the Qinghai Nan Shan, show a change from northward to southward flow between 6.5 and 3.8Ma. At the same location, sediment derived from the Qinghai Nan Shan appears at 6.1Ma. Finally, the initiation of progressively shallowing dips observed in deformed basin strata and a change to pebbly, fluvial deposits at 6.1Ma provide a minimum age for the onset of slip on the thrust fault that dips north-east beneath the Qinghai Nan Shan. We interpret a decrease in sediment accumulation rates since ~6Ma to indicate a reduction in Chaka basin accommodation space due to active faulting and folding along the Qinghai Nan Shan and incorporation of the basin into the wedge-top depozone. Declination anomalies indicate the beginning of counter-clockwise rotation since 6.1Ma, which we associate with local deformation, not regional block rotation. The emergence of the Qinghai Nan Shan near the end of the Miocene Epoch partitioned the once contiguous Chaka-Gonghe and Qinghai basin complex. In a regional framework, our study adds to a growing body of evidence that points to widespread initiation and/or reactivation of fault networks during the late Miocene across the north-eastern Tibetan Plateau. ?? 2011 The Authors. Basin Research ?? 2011 Blackwell Publishing Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists.

Molecular detection and characterization of Theileria infection in cattle and yaks from Tibet Plateau Region, China.

PubMed

Qin, Gege; Li, Youquan; Liu, Junlong; Liu, Zhijie; Yang, Jifei; Zhang, Lin; Liu, Guangyuan; Guan, Guiquan; Luo, Jianxun; Yin, Hong

2016-07-01

Theileriosis continues to threaten the livestock industry worldwide, but comprehensive epidemiological surveys for this disease have not been conducted in the Tibet Plateau Region, China. In this study, we screened 154 cattle blood samples from the Tibet Plateau Region (Lhasa, Lhoka, and Tianzhu), China, for detection of Theileria pathogens by polymerase chain reaction (PCR) with species-specific primers. The results revealed that the prevalence was 6.9 % (2/29) for Theileria orientalis and 27.6 % (8/29) for Theileria sinensis in Lhasa, 0 % (0/30) for T. orientalis and 26.7 % (8/30) for T. sinensis in Lhoka, and 0 % (0/95) for T. orientalis and 30.5 % (29/95) for T. sinensis in Tianzhu. Interestingly, Theileria luwenshuni, which was a previously reported pathogenic Theileria sp. in sheep and goats, was detected in blood samples from cattle and yaks for the first time, with a prevalence of 10 % (3/30) in Lhoka and 1.1 % (1/95) in Tianzhu. No other Theileria sp. was detected in these samples. T. sinensis and T. orientalis infections were detected in cattle and yaks, and T. luwenshuni was discovered for the first time in cattle and yaks in the Tibet Plateau Region, China.

Phylogeography of Sophora moorcroftiana Supports Wu's Hypothesis on the Origin of Tibetan Alpine Flora.

PubMed

Cheng, Shanmei; Qiong, La; Lu, Fan; Yonezawa, Takahiro; Yin, Ganqiang; Song, Zhiping; Wang, Yuguo; Yang, Ji; Zhang, Wenju

2017-06-01

Wu hypothesized that the Tibetan flora originated mostly from the paleotropical Tertiary flora in the Hengduan Mountains by adapting to the cold and arid environments associated with the strong uplift of the Qinghai-Tibet Plateau (QTP). Here, we combine the phylogeographic history of Sophora moorcroftiana with that of Sophora davidii to explore the speciation of S. moorcroftiana to test this hypothesis. We collected 151 individuals from 17 populations and sequenced 2 chloroplast fragments and the internal transcribed spacer of rDNA. Five chlorotypes and 9 ribotypes were detected but no significant phylogeographic structure was revealed. The integrated results of phylogeographic studies of these 2 species clearly support the progenitor-derivative relationship between them. We infer that the western peripheral population of S. davidii migrated westwards from the Hengduan Mountains to the middle reaches of the Yarlung Zangbo River and differentiated from its ancestor in the process of adaptation to increasingly cold and arid environments with the uplift of the QTP and finally evolved into S. moorcroftiana during the Late Pliocene. In addition, our findings shed light on the idea that natural selection, as imposed by climate differentiation (especially mean diurnal range and precipitation seasonality), directly drove this peripatric speciation event after geographic isolation. The speciation of S. moorcroftiana is a strong case supporting Wu's hypothesis about the origin of Tibet's flora. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Crustal and Uppermost Mantle Structure across the Tibet-Qinling Transition Zone in NE Tibet: Implications for Material Extrusion of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Ye, Z.; Li, J.; Gao*, R.; Song, X.; Li, Q.; Li, Y.; Huang, X.; Xiong, X.; Li, W.; WANG, Y.

2017-12-01

Based on a dense linear seismic array traversing across the eastern margin of the Tibetan plateau to the Qinling belt, we conducted joint inversion of receiver functions and surface wave dispersions under constraints of P-wave velocity and derived a crustal and uppermost mantle Vs profile simultaneously with a Vp/Vs ratio profile. Our observations indicate that the Qinling belt, which shows ratio Vp/Vs<1.8 indicative of intermediate-to-felsic components in the lower crust, is currently not acting as a channel accommodating extrusion of the mid-lower crustal flow; and extrusion of Tibet's ductile mantle flow through the Qinling belt as a channel would only be feasible in the sub-lithosphere depth (asthenosphere). Our results suggest that ductile material extrusion of the mid-lower crustal flow accompanied with fault-related tectonics and gravitational buoyancy resulted from lithospheric detachment (triggered by the asthenospheric flow) may jointly work on the plateau uplift and expansion in this Tibet-Qinling transition zone. Corresponding Author: R.Gao, ruigao126@126.com

Map the Permafrost and its Affected Soils and Vegetation on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zhao, L.; Sheng, Y.; Pang, Q.; Zou, D.; Wang, Z.; Li, W.; Wu, X.; Yue, G.; Fang, H.; Zhao, Y.

2015-12-01

Great amount of literatures had been published to deal with the actual distribution and changes of permafrost on the Tibetan Plateau (TP) on the basis of observed ground temperature dataset along Qinghai-Xizang Highway and/or Railway (QXH/R) during the last several decades. But there is very limited data available in the eastern part of the QXH/R and almost no observation in the western part of QXH/R not only for the observed permafrost data, but also for the dataset on ground surface conditions, such as soil and vegetation, which are used as model parameters, initial variables, or benchmark data sets for calibration, validation, and comparison in various Earth System Models (ESMs). To evaluate the status of permafrost and its environmental conditions, such as the distribution and thermal state of permafrost, soil and vegetation on the TP, detailed investigation on permafrost were conducted in 5 regions with different climatic and geologic conditions over the whole plateau from 2009 to 2013, and more than 100 ground temperatures (GTs) monitoring boreholes were drilled and equipped with thermistors, of which 10 sites were equipped with automatic meteorological stations. Geophysical prospecting methods, such as ground penetrating radar (GPR) and electromagnetic prospecting, were used in the same time to detect the permafrost distribution and thicknesses. The monitoring data revealed that the thermal state of permafrost was well correlated with elevation, and regulated by annual precipitation, local geological, geomorphological and hydrological conditions through heat exchanges between ground and atmosphere. Different models, including GTs statistical model, Common Land Surface Model (CoLM), Noah land surface model and TTOP models, were used to map the permafrost in 5 selected regions and the whole TP, while the investigated and monitored data were used as calibration and validation for all models. Finally, we compiled the permafrost map of the TP, soil and vegetation map within the permafrost regions on the TP. We also compiled the soil organic carbon density map of permafrost affected soils on the TP. An overview on permafrost thickness, GTs, ice content was statistically summarized based on investigation data.

Timing and Magnitude of Upper Crustal Shortening in the Gonghe Basin Region of the Northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Craddock, W. H.; Kirby, E.; Harkins, N.; Zhang, H.

2008-12-01

Characterizing the space-time patterns of the growth of high topography in Asia is an important step toward a deeper understanding of the mechanics of intracontinental deformation and its influence on global climate. In northeastern Tibet, there is emerging evidence that a number of ranges around the margins of the plateau experienced a pulse of deformation in the Late Miocene (ca. 12-8 Ma). It remains uncertain, however, whether this event was confined to the margins of the plateau, or whether interior regions deformed synchronously. Here we present a preliminary assessment of the timing and magnitude of upper crustal shortening along the margins of the Gonghe-Tongde basin complex. The Gonghe basin is located at the boundary between the high plateau of central Tibet and the southern flank of the Qilian Shan, and as such it is well-suited as a site to begin reconstructing patterns of plateau growth. The basin is overthrust by two regionally-extensive fault systems, the Qinghai Nan Shan (QNS) fault system on the north side and the Gonghe Nan Shan (GNS) fault system on the south side. Both fault systems are associated with deformation of Tertiary strata; variations in dip, sedimentary facies, and provenance are used to interpret the onset of growth along the margins of the Gonghe basin. A combination of the architecture of pre- and syntectonic basin strata, field measurements of fault dip, fault plane solutions, and topographic analysis of fold backlimbs for the GNS and QNS leads us to infer that the fault systems are a) trishear fault propagation style thrust faults and b) south vergent, with ~30 degree fault ramps soleing into a gently dipping decollement. Reconstructions of fold evolution suggest that the area has experienced > 5 km of upper crustal shortening in the late Cenozoic. A combination of magnetostratigraphy, biostratigraphy and cosmogenic burial ages provides preliminary age control. South of the GNS, a 250 m thick package of growth related strata are found to be 3.4 - 0.5 Ma. A 500 m thick exposure of growth strata on the north side of the range is also interpreted to be Plio-Quaternary in age. At present, however, we can only place a minimum bound on the onset of deformation of ca. 4-5 Ma. In light of a companion study interpreting the onset of deformation along the QNS at >= 5-7 Ma (Zhang H., in review), deformation of the Gonghe region appears to be slightly more recent than at the plateau margins. Historic seismicity and deformation of late-Quaternary alluvial surfaces on both fault systems indicate that these structures have remained active into the Pleistocene.

Insight into microevolution of Yersinia pestis by clustered regularly interspaced short palindromic repeats.

PubMed

Cui, Yujun; Li, Yanjun; Gorgé, Olivier; Platonov, Mikhail E; Yan, Yanfeng; Guo, Zhaobiao; Pourcel, Christine; Dentovskaya, Svetlana V; Balakhonov, Sergey V; Wang, Xiaoyi; Song, Yajun; Anisimov, Andrey P; Vergnaud, Gilles; Yang, Ruifu

2008-07-09

Yersinia pestis, the pathogen of plague, has greatly influenced human history on a global scale. Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR), an element participating in immunity against phages' invasion, is composed of short repeated sequences separated by unique spacers and provides the basis of the spoligotyping technology. In the present research, three CRISPR loci were analyzed in 125 strains of Y. pestis from 26 natural plague foci of China, the former Soviet Union and Mongolia were analyzed, for validating CRISPR-based genotyping method and better understanding adaptive microevolution of Y. pestis. Using PCR amplification, sequencing and online data processing, a high degree of genetic diversity was revealed in all three CRISPR elements. The distribution of spacers and their arrays in Y. pestis strains is strongly region and focus-specific, allowing the construction of a hypothetic evolutionary model of Y. pestis. This model suggests transmission route of microtus strains that encircled Takla Makan Desert and ZhunGer Basin. Starting from Tadjikistan, one branch passed through the Kunlun Mountains, and moved to the Qinghai-Tibet Plateau. Another branch went north via the Pamirs Plateau, the Tianshan Mountains, the Altai Mountains and the Inner Mongolian Plateau. Other Y. pestis lineages might be originated from certain areas along those routes. CRISPR can provide important information for genotyping and evolutionary research of bacteria, which will help to trace the source of outbreaks. The resulting data will make possible the development of very low cost and high-resolution assays for the systematic typing of any new isolate.

[Farmer's perception and adaptation intention for climate change in high-cold eco-fragile region: A case of Gannan Plateau, China.

PubMed

Zhao, Xue Yan; Xue, Bing

2016-07-01

In order to provide reference for formulating the effective policies of climate change, we selected Ganan Plateau located in the eastern margin of Qinghai-Tibet Plateau as the study area, and used the farmer's investigation data to analyze the impact of the farmers' perception of climate change on their adaptation indention. The results showed that the farmer's severity perception of climate change declined from the pure agriculture household to the household with combined occupation, and to the non-agriculture household, but the farmer's adaptation efficacy perception was vice versa. Moreover, all of the perceived probability, self-efficacy and adaptation cost of the household with combined occupation were highest, those of the non-agriculture household were the second place and those of the pure agriculture household were the lowest. The farmer's positive adaptation indention of climate change increased from the pure agriculture household to the household with combined occupation, and to the non-agriculture household. Increasing the perceived risk and adaptation efficacy would promote the farmer's positive adaptation intention, but increasing the perceived adaptation cost would promote the farmers' passive adaptation intention. Meanwhile, the more the farmer's agricultural acreage, livestock, income and optimistic degree were, the stronger the farmer's positive adaptation intention was; But the more the farmers' fixed capital, unpaid cash assistance opportunities, relative number and the number of people offering help were, the weaker the farmers' positive adaptation intention was. Finally, we pointed out the measures of promoting the positive adaptation intention and the problems on which we should focus in the future research.

A taxonomic revision of the silphaeformis species-group of the genus Tachinus Gravenhorst (Staphylinidae, Tachyporinae) from China.

PubMed

Feng, Ting; Schülke, Michael; Li, Li-Zhen

2013-01-01

The Chinese species of the silphaeformis group of the genus Tachinus Gravenhorst are revised with fifteen species being treated. Thirteen of them are described as new: T. armatus Feng & Li, sp. n. (Sichuan), T. cavazzutii Feng, Li & Schülke, sp. n. (Sichuan), T. coronatus Feng, Li & Schülke, sp. n. (Ningxia, Qinghai), T. hercules Feng, Li & Schülke, sp. n. (Sichuan), T. hujiayaoi Feng, Li & Schülke, sp. n. (Shaanxi), T. jiuzhaigouensis Feng, Li & Schülke, sp. n. (Sichuan), T. linzhiensis Feng & Li, sp. n. (Tibet), T. maderianus Feng & Li, sp. n. (Sichuan), T. mengdaensis Feng, Li & Schülke, sp. n. (Qinghai), T. oblongoelytratus Feng & Li, sp. n. (Sichuan), T. parahercules Feng, Li & Schülke, sp. n. (Sichuan), T. paralinzhiensis Feng & Li, sp. n. (Tibet), and T. yini Feng, Li & Schülke, sp. n. (Sichuan). The two known species are redescribed based on the holotypes and additional material. Illustrations of the habitus and major diagnostic characters, distributional maps, and identification keys of all species are included.

Mechanism of the surface runoff generation processes of a permafrost watershed in the Qinghai-Tibet plateau

NASA Astrophysics Data System (ADS)

Genxu, W.

2017-12-01

There is a lack of knowledge about how to quantify runoff generation and the hydrological processes operating in permafrost catchments on permafrost-dominant catchments. To understand the mechanism of runoff generation processes in permafrost catchments, a typical headwater catchment with continuous permafrost on the Tibetan Plateau was measured. A new approach is presented in this study to account for runoff processes on the spring thawing period and autumn freezing period, when runoff generation clearly differs from that of non-permafrost catchments. This approach introduces a soil temperature-based water saturation function and modifies the soil water storage curve with a soil temperature threshold. The results show that surface soil thawing induced saturation excess runoff and subsurface interflow account for approximately 66-86% and 14-34% of total spring runoff, respectively, and the soil temperature significantly affects the runoff generation pattern, the runoff composition and the runoff coefficient with the enlargement of the active layer. The suprapermafrost groundwater discharge decreases exponentially with active layer frozen processes during autumn runoff recession, whereas the ratio of groundwater discharge to total runoff and the direct surface runoff coefficient simultaneously increase. The bidirectional freezing of the active layer controls and changes the autumn runoff processes and runoff composition. The new approach could be used to further develop hydrological models of cold regions dominated by permafrost.

Preliminary estimation of the realistic optimum temperature for vegetation growth in China.

PubMed

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

Preliminary Estimation of the Realistic Optimum Temperature for Vegetation Growth in China

NASA Astrophysics Data System (ADS)

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

The growth of the Tibetan Plateau and its possible impacts on the South Asian Monsoon in paleoclimate

NASA Astrophysics Data System (ADS)

Molnar, P. H.; Rajagopalan, B.

2012-12-01

To a first approximation, the collision of the Indian subcontinent with the rest of Eurasia and the continued penetration of India into Eurasia have created the Tibetan Plateau, but details of timing, dimensions of the evolving plateau, and processes responsible for growing topography remain controversial. Many imagine that a narrow plateau, similar to the present-day Central Andes, bounded southern Eurasia when India arrived, apparently at ~50 Ma, but some doubt this date of collision. Crustal thickening of the southern margin of Eurasia in response to India's penetration into that region and isostatic balance of that thickened crust account for most of the present-day, and presumably past, surface heights. The surface throughout the northern half of the plateau apparently started to rise shortly after collision, near 45 Ma if not earlier. Thus, rather than growing wider over time, the N-S dimension of high Tibetan terrain may have grown narrower as its surface rose higher. A change in style of deformation near 15-10 Ma has led some to imagine that the plateau reached its maximum elevation in that period, perhaps abruptly. Moreover, subsequently (or concurrently) the E-W dimension of Tibet seems to have increased. The Tibetan Plateau can affect regional climate both mechanically by disrupting the flow of air near it and thermally by affecting the temperature structure of the overlying atmosphere, for the surface of Tibet is hotter than air at the same pressure and latitude over lower regions. Recent theoretical work and subsequent general circulation model runs by Boos and Kuang suggest that Tibet's principal role in affecting the South Asian Monsoon may be to block cool dry air from the northwest, which enables hot moist air to develop at relatively high latitudes over India. Although their work does not deny heating of air over Tibet a role in the South Asian Monsoon, it suggests that such heating role might play a modest role. To assess the importance of such heating, we correlated moist static energy over Tibet with rainfall over the Indian subcontinent and with winds along the coast of Arabia. Such correlations are significant, if larger for rainfall than for winds, for the early and late monsoon seasons, but insignificant for late June to August, the main monsoon season. Such correlations suggest that the apparent strengthening of winds over the Arabian Sea near 10 Ma might have been due to a rise in Tibet's surface at that time, but paleoaltimetry evidence offers no support for such a rise.

The composition, localization and function of low-temperature-adapted microbial communities involved in methanogenic degradations of cellulose and chitin from Qinghai-Tibetan Plateau wetland soils.

PubMed

Dai, Y; Yan, Z; Jia, L; Zhang, S; Gao, L; Wei, X; Mei, Z; Liu, X

2016-07-01

To reveal the microbial communities from Qinghai-Tibetan Plateau wetland soils that have the potential to be used in the utilization of cellulosic and chitinous biomass at low temperatures (≤25°C). Soil samples collected from six wetlands on Qinghai-Tibetan Plateau were supplemented with or without cellulose and chitin flakes, and anaerobically incubated at 25 and 15°C; high-throughput 16S rRNA gene sequencing was used to access the composition and localization (in the slurry and on the surface) of enriched microbial communities; a hypothetical model was constructed to demonstrate the functional roles of involved microbes mainly at genus level. Overall, microbial communities from Qinghai-Tibetan Plateau wetlands showed significant potential to convert both cellulose and chitin to methane at low temperatures; Clostridium III, Clostridium XIVa, Paludibacter, Parcubacteria, Saccharofermentans, Pelotomaculum, Methanosaeta, Methanobrevibacter, Methanoregula, Methanospirillum and Methanosarcina participated in methanogenic degradation of both cellulose and chitin through the roles of hydrolytic, saccharolytic and secondary fermenters and methanogens respectively. Acetotrophic methanogens were mainly enriched in the slurries, while hydrogenotrophic methanogens could be both in the slurries and on the surface. The composition and localization of microbial communities that could effectively convert cellulose and chitin to methane at low temperatures have been revealed by high-throughput 16S rRNA gene sequencing methods, and reviewing the literatures on the microbial pure culture helped to elucidate functional roles of significantly enriched microbes. This study will contribute to the understanding of carbon and nitrogen cycling of cellulose and chitin in cold-area wetlands and provide fundamental information to obtain microbial resources for the utilization of biomass wastes at low temperatures. © 2016 The Society for Applied Microbiology.

Golden Key Program. Common Education for Visually Impaired Children in Western China.

ERIC Educational Resources Information Center

Xu, Bailun

This paper describes a new program in the Western provinces of China (Guangxi, Guizhou, Yunnan, Gansu, Ningxia, Qinghai, Xinjiang, Tibet, and Inner Mongolia) that is designed to integrate 20,000 children with low-vision into general education classrooms. The Golden Key Research Center of Education for Visually Impaired has been working with the…

Developing a thermal characteristic index for lithology identification using thermal infrared remote sensing data

NASA Astrophysics Data System (ADS)

Wei, Jiali; Liu, Xiangnan; Ding, Chao; Liu, Meiling; Jin, Ming; Li, Dongdong

2017-01-01

In remote sensing petrology fields, studies have mainly concentrated on spectroscopy remote sensing research, and methods to identify minerals and rocks are mainly based on the analysis and enhancement of spectral features. Few studies have reported the application of thermodynamics for lithology identification. This paper aims to establish a thermal characteristic index (TCI) to explore rock thermal behavior responding to defined environmental systems. The study area is located in the northern Qinghai Province, China, on the northern edge of the Qinghai-Tibet Plateau, where mafic-ultramafic rock, quartz-rich rock, alkali granite rock and carbonate rock are well exposed; the pixel samples of these rocks and vegetation were obtained based on relevant indices and geological maps. The scatter plots of TCI indicate that mafic-ultramafic rock and quartz-rich rock can be well extracted from other surface objects when interference from vegetation is lower. On account of the complexity of environmental systems, three periods of TCI were used to construct a three-dimensional scatter plot, named the multi-temporal thermal feature space (MTTFS) model. Then, the Bayes discriminant analysis algorithm was applied to the MTTFS model to extract rocks quantitatively. The classification accuracy of mafic-ultramafic rock is more than 75% in both training data and test data, which suggests TCI can act as a sensitive indicator to distinguish rocks and the MTTFS model can accurately extract mafic-ultramafic rock from other surface objects. We deduce that the use of thermodynamics is promising in lithology identification when an effective index is constructed and an appropriated model is selected.

[Phylogeny and divergence time estimation of Schizothoracinae fishes in Xinjiang].

PubMed

Ayelhan, Haysa; Guo, Yan; Meng, Wei; Yang, Tianyan; Ma, Yanwu

2014-10-01

Based on combined data of mitochondrial COI, ND4 and 16S RNA genes, molecular phylogeny of 4 genera, 10 species or subspecies of Schizothoracinae fishes distributed in Xinjiang were analyzed. The molecular clock was calibrated by divergence time of Cyprininae and geological segregation event between the upper Yellow River and Qinghai Lake. Divergence time of Schizothoracinae fishes was calculated, and its relationship with the major geological events and the climate changes in surrounding areas of Tarim Basin was discussed. The results showed that genus Aspiorhynchus did not form an independent clade, but clustered with Schizothorax biddulphi and S. irregularis. Kimura 2-parameter model was used to calculate the genetic distance of COI gene, the genetic distance between genus Aspiorhynchus and Schizothorax did not reach genus level, and Aspiorhynchus laticeps might be a specialized species of genus Schizothorax. Cluster analysis showed a different result with morphological classification method, and it did not support the subgenus division of Schizothorax fishes. Divergence of two groups of primitive Schizothoracinae (8.18Ma) and divergence of Gymnodiptychus dybowskii and Diptychus maculates (7.67Ma) occurred in late Miocene, which might be related with the separation of Kunlun Mountain and north Tianshan Mountain River system that was caused by the uplift of Qinghai-Tibet Plateau and Tianshan Mountain, and the aridification of Tarim Basin. The terrain of Tarim Basin that was affected by Quaternary Himalayan movement was high in west but low in east, as a result, Lop Nor became the center of surrounding mountain rivers in Tarim Basin, which shaped the distribution pattern of genus Schizothorax.

Free and Bound Phenolic Compound Content and Antioxidant Activity of Different Cultivated Blue Highland Barley Varieties from the Qinghai-Tibet Plateau.

PubMed

Yang, Xi-Juan; Dang, Bin; Fan, Ming-Tao

2018-04-11

In this study, the polyphenols composition and antioxidant properties of 12 blue highland barley varieties planted on the Qinghai-Tibet Plateau area were measured. The contents of the free, bound and total phenolic acids varied between 166.20-237.60, 170.10-240.75 and 336.29-453.94 mg of gallic acid equivalents per 100 g of dry weight (DW) blue highland barley grains, while the free and bound phenolic acids accounted for 50.09% and 49.91% of the total phenolic acids, respectively. The contents of the free, bound and total flavones varied among 20.61-25.59, 14.91-22.38 and 37.91-47.98 mg of catechin equivalents per 100 g of dry weight (DW) of blue highland barley grains, while the free and bound flavones accounted for 55.90% and 44.10% of the total flavones, respectively. The prominent phenolic compounds in the blue hulless barley grains were gallic acid, benzoic acid, syringic acid, 4-coumaric acid, naringenin, hesperidin, rutin, (+)-catechin and quercetin. Among these, protocatechuic acid, chlorogenic acid and (+)-catechin were the major phenolic compounds in the free phenolics extract. The most abundant bound phenolics were gallic acid, benzoic acid, syringic acid, 4-coumaric acid, benzoic acid, dimethoxybenzoic acid, naringenin, hesperidin, quercetin and rutin. The average contribution of the bound phenolic extract to the DPPH • free radical scavenging capacity was higher than 86%, that of free phenolic extract to the ABTS •+ free radical scavenging capacity was higher than 79%, and that of free phenolic (53%) to the FRAP antioxidant activity was equivalent to that of the bound phenol extract (47%). In addition, the planting environment exerts a very important influence on the polyphenol composition, content and antioxidant activity of blue highland barley. The correlation analysis showed that 2,4-hydroxybenzoic acid and protocatechuic acid were the main contributors to the DPPH • and ABTS •+ free radical scavenging capacity in the free phenolic extract, while chlorogenic acid, vanillic acid, ferulic acid and quercetin were the main contributors to the free radical scavenging capacity in the bound phenol extract. The study results show that the blue highland barley grains have rich phenolic compounds and high antioxidant activity, as well as significant varietal differences. The free and bound phenolic extracts in the blue hulless barley grains have an equivalent proportion in the total phenol, and co-exist in two forms. They can be used as a potential valuable source of natural antioxidants, and can aid in enhancing the development and daily consumption of foods relating to blue highland barley.

Source and Path Calibration in Regions of Poor Crustal Propagation Using Temporary, Large-Aperture, High-Resolution Seismic Arrays (Postprint). Annual Report 3

DTIC Science & Technology

2012-06-04

central Tibetan Plateau. Automated hypocenter locations in south- central Tibet were finalized. Refinements included an update of the model used for... central Tibet. A subset of ~7,900 events with 25+ arrivals is considered well-located based on kilometer-scale differences relative to manually located...propagation in the Nepal Himalaya and the south- central Tibetan Plateau. The 2002–2005 experiment consisted of 233 stations along a dense 800 km linear

Vegetation greenness trend (2000 to 2009) and the climate controls in the Qinghai-Tibetan Plateau

USGS Publications Warehouse

Zhang, Li; Guo, Huadong; Ji, Lei; Lei, Liping; Wang, Cuizhen; Yan, Dongmei; Li, Bin; Li, Jing

2013-01-01

The Qinghai-Tibetan Plateau has been experiencing a distinct warming trend, and climate warming has a direct and quick impact on the alpine grassland ecosystem. We detected the greenness trend of the grasslands in the plateau using Moderate Resolution Imaging Spectroradiometer data from 2000 to 2009. Weather station data were used to explore the climatic drivers for vegetation greenness variations. The results demonstrated that the region-wide averaged normalized difference vegetation index (NDVI) increased at a rate of 0.036  yr−1. Approximately 20% of the vegetation areas, which were primarily located in the northeastern plateau, exhibited significant NDVI increase trend (p-value <0.05). Only 4% of the vegetated area showed significant decrease trends, which were mostly in the central and southwestern plateau. A strong positive relationship between NDVI and precipitation, especially in the northeastern plateau, suggested that precipitation was a favorable factor for the grassland NDVI. Negative correlations between NDVI and temperature, especially in the southern plateau, indicated that higher temperature adversely affected the grassland growth. Although a warming climate was expected to be beneficial to the vegetation growth in cold regions, the grasslands in the central and southwestern plateau showed a decrease in trends influenced by increased temperature coupled with decreased precipitation.

Snow effects on alpine vegetation in the Qinghai-Tibetan Plateau

USGS Publications Warehouse

Wang, Kun; Zhang, Li; Qiu, Yubao; Ji, Lei; Tian, Feng; Wang, Cuizhen; Wang, Zhiyong

2013-01-01

Understanding the relationships between snow and vegetation is important for interpretation of the responses of alpine ecosystems to climate changes. The Qinghai-Tibetan Plateau is regarded as an ideal area due to its undisturbed features with low population and relatively high snow cover. We used 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) datasets during 2001–2010 to examine the snow–vegetation relationships, specifically, (1) the influence of snow melting date on vegetation green-up date and (2) the effects of snow cover duration on vegetation greenness. The results showed that the alpine vegetation responded strongly to snow phenology (i.e., snow melting date and snow cover duration) over large areas of the Qinghai-Tibetan Plateau. Snow melting date and vegetation green-up date were significantly correlated (p < 0.1) in 39.9% of meadow areas (accounting for 26.2% of vegetated areas) and 36.7% of steppe areas (28.1% of vegetated areas). Vegetation growth was influenced by different seasonal snow cover durations (SCDs) in different regions. Generally, the December–February and March–May SCDs played a significantly role in vegetation growth, both positively and negatively, depending on different water source regions. Snow's positive impact on vegetation was larger than the negative impact.

PCR-DGGE Analysis on Microbial Community Structure of Rural Household Biogas Digesters in Qinghai Plateau.

PubMed

Han, Rui; Yuan, Yongze; Cao, Qianwen; Li, Quanhui; Chen, Laisheng; Zhu, Derui; Liu, Deli

2018-05-01

To investigate contribution of environmental factor(s) to microbial community structure(s) involved in rural household biogas fermentation at Qinghai Plateau, we collected slurry samples from 15 digesters, with low-temperature working conditions (11.1-15.7 °C) and evenly distributed at three counties (Datong, Huangyuan, and Ledu) with cold plateau climate, to perform polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and further sequencing. The bacterial communities in the total 15 digesters were classified into 38 genera with Mangroviflexus (12.1%) as the first dominant, and the archaeal communities into ten genera with Methanogenium (38.5%) as the most dominant. For each county, the digesters with higher biogas production, designated as HP digesters, exclusively had 1.6-3.1 °C higher fermentation temperature and the unique bacterial structure composition related, i.e., unclassified Clostridiales for all the HP digesters and unclassified Marinilabiliaceae and Proteiniclasticum for Ledu HP digesters. Regarding archaeal structure composition, Methanogenium exhibited significantly higher abundances at all the HP digesters and Thermogymnomonas was the unique species only identified at Ledu HP digesters with higher-temperature conditions. Redundancy analysis also confirmed the most important contribution of temperature to the microbial community structures investigated. This report emphasized the correlation between temperature and specific microbial community structure(s) that would benefit biogas production of rural household digesters at Qinghai Plateau.

Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

PubMed

Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

2013-01-01

The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

Effect of Degradation Intensity on Grassland Ecosystem Services in the Alpine Region of Qinghai-Tibetan Plateau, China

PubMed Central

Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

2013-01-01

The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau. PMID:23469278

Spatial distributing characteristics of land use in the southern slope of mid-Himalaya Mountains

NASA Astrophysics Data System (ADS)

Lu, Chen

2014-12-01

The southern slope of mid-Himalayan Mountains located in China's Qomolangma National Natural Reserve in Tibet Autonomous Region, is made up of several non-continuous valleys. The study collected the data including DEM(SRTM90m), 1/250,000 land use map(year 2000), 1/100 million vegetation types map ,satellite images of 4 typical valleys on Google Earth Planet Map. Made use of ArcGIS9.3 spatial analysis technology, analyzed into the 2 aspects— Mountain altitudinal belts and slope gradient of soil types of Qinghai-Tibet Plateau, so as to abtain the spatial distributing characteristics of farmland and grassland in the research areas. The conclusions indicates that: (1)no farmland below 2200m altitude, land use is influenced intensively by slope gradient factor in the altitude range of < 2500m; (2)it is in 2500m-3800m altitude range meanwhile on the 2 farming suitable slope gradient belts(<5°, 5-15°) that the very focus zone has got the relatively larger potential, suitability and yield of farming utilization; (3)on the 3 grazing suitable slope gradient belts(<5°,5-15°,15-35°), the respective fodder quantities of the 4 valleys has low differences. land use of the 4 valleys are intensively restricted by altitude and slope gradient factors so that cultivating and grazing activities take place widely on the farming unsuitable slope gradient belts(15-35°,>35°) and grazing unsuitable slope gradient belt(>35°), which is disadvantaged to ecological environmental protection and rational utilization of land resources.

Eco-environmental degradation in the source region of the Yellow River, Northeast Qinghai-Xizang Plateau.

PubMed

Feng, Jianmin; Wang, Tao; Xie, Changwei

2006-11-01

The Yellow River is the second longest river in China and the cradle of the Chinese civilization. The source region of the Yellow River is the most important water holding area for the Yellow River, about 49.2% of the whole runoff comes from this region. However, for the special location, it is a region with most fragile eco-environment in China as well. Eco-environmental degradation in the source region of the Yellow River has been a very serious ecological and socially economic problem. According to census data, historical documents and climatic information, during the last half century, especially the last 30 years, great changes have taken place in the eco-environment of this region. Such changes are mainly manifested in the temporal-spatial changes of water environment, deglaciation, permafrost reduction, vegetation degeneracy and desertification extent, which led to land capacity decreasing and river disconnecting. At present, desertification of the region is showing an accelerating tendency. This paper analyzes the present status of eco-environment degradation in this region supported by GIS and RS, as well as field investigation and indoor analysis, based on knowledge, multi-source data is gathered and the classification is worked out, deals with their natural and anthropogenic causes, and points out that in the last half century the desertification and environmental degradation of this region are mainly attributed to human activities under the background of regional climate changes. To halt further degradation of the environment of this region, great efforts should be made to use land resources rationally, develop advantages animal agriculture and protect the natural grassland.

Host species shapes the co-occurrence patterns rather than diversity of stomach bacterial communities in pikas.

PubMed

Li, Huan; Li, Tongtong; Tu, Bo; Kou, Yongping; Li, Xiangzhen

2017-07-01

The mammalian stomach acts as an important barrier against ingested pathogens into the entire gastrointestinal tract, thereby playing a key role in host health. However, little is known regarding to the stomach microbial compositions in wild mammals and the factors that may influence the community compositions. Using high-throughput sequencing of the 16S rRNA gene, we characterized the stomach bacterial community compositions, diversity, and interactions in two common pika (Ochotona sp.) species in China, including Plateau pikas (Ochotona curzoniae) and Daurian pikas (Ochotona daurica) living in the Qinghai-Tibet Plateau and the Inner Mongolia Grassland, respectively. The bacterial communities can be divided into two distinct phylogenetic clusters. The most dominant bacteria in cluster I were unclassified bacteria. Cluster II was more diverse, predominantly consisting of Bacteroidetes, followed by unclassified bacteria, Firmicutes and Proteobacteria. Three dominant genera (Prevotella, Oscillospira, and Ruminococcus) in pika stomachs were significantly enriched in cluster II. In addition, seasons, host species, and sampling sites as well as body weight and sex had no significant impacts on the composition and diversity of pika stomach communities. Interestingly, Plateau pikas harbored a more complex bacterial network than Daurian pikas, and these two pika species showed different co-occurrence patterns. These results suggested that the pika stomach harbors a diverse but relatively stable and unique bacterial community, which is independent on host (host species, body weight, and sex) and measured environmental factors (sampling sites and seasons). Interestingly, host species shapes the microbial interactions rather than diversity of stomach bacterial communities in pikas, reflecting specific niche adaptation of stomach bacterial communities through species interactions.

Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae)

PubMed Central

Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

2016-01-01

Testis-specific lactate dehydrogenase (LDH-C4) is one of the lactate dehydrogenase (LDH) isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae) belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4), Lactate Dehydrogenase B4 (LDH-B4), and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis (PAGE). The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km) of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki) of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L), LDH-B4 (Ki = 23.800 mmol/L), and LDH-C4 (Ki = 65.500 mmol/L). These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4. PMID:26751442

Genetic diversity of the Tibetan antelope (Pantholops hodgsonii) population of Ladakh, India, its relationship with other populations and conservation implications.

PubMed

Ahmad, Khursheed; Kumar, Ved P; Joshi, Bheem Dutt; Raza, Mohamed; Nigam, Parag; Khan, Anzara Anjum; Goyal, Surendra P

2016-10-21

The Tibetan antelope (Pantholops hodgsonii), or chiru, is an endangered antelope, distributed in China [Xinjiang, Xizang, Qinghai, Zhuolaihu Lake (Breeding habitat)], and India (Aksai Chin and Ladakh). There is a global demand for the species prized wool, which is used in weaving shahtoosh shawls. Over the years, the population of the Tibetan antelope has drastically declined from more than a million to a few thousand individuals, mainly due to poaching. Field studies undertaken in Ladakh, India also indicated winter migration of the population to Tibet. Migration between winter and calving habitats is well established to be female-biased across the Qinghai Tibetan Plateau (QTP). For effective conservation planning, genetic characterization is considered the best way to understand the likely impact of threats for ensuring the long-term viability of the population. In this regard, genetic characteristics of all Chinese populations are well-studied using mitochondrial and microsatellite markers, but information is lacking for the Indian population. Therefore, using the control region marker, we document for the first time the genetic variation of the Indian population of the Tibetan antelope, the extent of migration and its relationships with other populations of China. The partial fragment of control region (259 bp) marker was successfully amplified in 30 Tibetan antelope samples that were collected from the Chang Chenmo Valley in eastern Ladakh, India. We also retrieved control region sequences (n = 88) available in the public domain from GenBank of different Chinese populations. Low levels of nucleotide (π; 0.004) and haplotype (hd; 0.543) diversity were observed in the Indian population when compared to Chinese populations (π = 0.01357-0.02048 and hd = 0.889-0.986). Commonly used indices (Tajima's D and Fu's Fs) were analyzed for inferring the demographic history of the Indian populations, and all values were negative indicating population expansion or demographic equilibrium, though nonsignificant. We observed five haplotypes in the Indian population, and these were not reported in previously studied populations of QTP. Bayesian-based phylogenetic analysis indicates the presence of four clades, however, the posterior probability support for three of these clades is weak (<0.5). Of these, the Indian population formed a distinct clade, whereas the Chinese populations exhibited shared haplotypes, and no geographic structure was observed. Median-joining network analysis was conducted for 46 haplotypes in the overall population, except the samples from India which showed a star-like topology. The Indian population is separated by one median vector from the Chinese population. The present study revealed the presence of different sub-clades in the Bayesian phylogenetic tree and five new haplotypes only in the Indian population or sampling location. Furthermore, in the phylogenetic tree, Indian haplotypes of Tibetan antelopes were clustered with the haplotype reported in the Chinese population of the Xinjiang region. Median-joining network analysis showed shared haplotypes pattern in all populations of QTP except the samples from India which showed new haplotypes. Given the presence of low nucleotide and haplotype diversity in eastern Ladakh populations and limited information available for populations of the western side in its range, we suggest to include genetic studies of Tibetan antelope populations around Aksai Chin (Fig. 1) under the proposed transboundary agenda between India and China and assess relationships with other populations. Such understanding would enable the planning of conservation strategies for ensuring long-term survival of westernmost populations in its range, and if required, it would establish connectivity with the other populations.

[Diversity and faunal analysis of crustaceans in Potatso National Park, Shangri-La, China].

PubMed

Shu, Shu-Sen; Chen, Fei-Zhou; Yang, Jun-Xing; Yang, Xiao-Jun; Chen, Xiao-Yong

2013-06-01

Potatso National Park was the first national park in mainland China, preceded by the earlier Bitahai Nature Reserve. Located in the northwest of Yunnan and on the southeast of Qinghai-Tibet plateau, Potatso is a typical low latitude and high elevation wetland nature reserve, with large areas of coniferous forest around alpine lakes and both wetland and water area ecosystems. In August, 2011, we undertook a survey of crustaceans in the park, sampling lakes, ponds, streams, and rivers throughout Potatso. We found a total of 29 species (including varieties) belonging to 24 genera and 11 families. Notable discoveries include Parartemiopsis sp, Arctodiaptomus parvispinus and Simocephalus congener, which are the first examples of these species to be recorded in China. Likewise, Gammarus bitaensis is a unique crustacean found only in Potatso National Park and Thermocyclops dumonti and Gammarus paucispinus are both endemic species to northwestern Yunnan. The overall faunal characteristics of crustaceans in the park also revealed several things about Potatso: (1) Cosmopolitan and Palaearctic elements reach 48.27% and 37.93%, clearly showing the Palaearctic element as the dominant fauna; (2) most of the crustacean, such as Arctodiaptomus parvispinus and Gammarus, are typical alpine types, confirming that Potatso has feature typical of alpine and plateau fauna; and (3) the proportion of endemic and rare crustacean species in Potatso National Park is approximately 10%, suggesting that the Potatso National Park in particular and the northwest of Yunnan in general have a unique geological and evolutionary history.

Niche conservatism in Gynandropaa frogs on the southeastern Qinghai-Tibetan Plateau.

PubMed

Hu, Junhua; Broennimann, Olivier; Guisan, Antoine; Wang, Bin; Huang, Yan; Jiang, Jianping

2016-09-07

The role of ecological niche in lineage diversification has been the subject of long-standing interest of ecologists and evolutionary biologists. Gynandropaa frogs diversified into three independent clades endemic to the southeastern Qinghai-Tibetan Plateau. Here, we address the question whether these clades kept the same niche after separation, and what it tells us about possible diversification processes. We applied predictions in geographical (G)-space and tests of niche conservatism in environmental (E)-space. Niche models in G-space indicate separate regions with high suitability for the different clades, with some potential areas of sympatry. While the pair of central and eastern clades displayed the largest niche overlap for most variables, and strict niche equivalency was rejected for all clade-pairs, we found no strong evidence for niche divergence, but rather the signature of niche conservatism compared to null models in E-space. These results suggest a common ancestral ecological niche, and as such give good support to divergence through allopatric speciation, but alternative explanations are also possible. Our findings illustrate how testing for niche conservatism in lineage diversification can provide insights into underlying speciation processes, and how this information may guide further research and conservation practices, as illustrated here for amphibians on the Qinghai-Tibetan Plateau.

[Burden of disease attributable to high- sodium diets in China, 2013].

PubMed

Liu, M; Li, Y C; Liu, S W; Wang, L J; Liu, Y N; Yin, P; Liu, J M; You, J L; Zhou, M G

2016-09-06

Objective: To examine the burden of disease(BOD)attributable to high-sodium diets in China in 2013. Methods: Data were extracted from the 2013 Global Burden of Disease Study for China to examine the BOD attributable to high-sodium diets in 2013, gender, and disease composition. Measurements for attributable BOD were population attributable fraction(PAF), deaths, standardized mortality and disability-adjusted life years(DALY)(not including Taiwan, China). An average world population age-structure for the period 2000-2025 was adopted to calculate age-standardized rates. Results: In 2013, deaths attributable to high-sodium diets accounted for 12.6% of all deaths and 14.5% of chronic disease deaths. Overall, 7.8% of deaths because of neoplasms, 25.2% of cardiovascular disease deaths, and 22.9% of chronic kidney disease deaths were attributable to high-sodium diets. A total of 1 176 553 deaths were attributable to high-sodium diets and the standardized mortality was 91.5/100 000, which was higher in men than in women(121.7/100 000 and 63.0/100 000, respectively). Overall, 22.759 million DALYs were attributable to high-sodium diets. The DALY standardized rate was 1 588.0/100 000, which was higher in men than in women(2 189.7/100 000 and 993.2/100 000, respectively). When compared by province, PAF in Xinjiang(25.0%), Qinghai(23.7%), Shanxi(23.2%), Tibet(22.1%)and Shandong(20.5%)was higher than other provinces. The standardized mortality in Xinjiang(239.4/100 000), Qinghai(238.9/100 000), Tibet(221.7/100 000), Shanxi(166.2/100 000)and Hebei(149.9/100 000)were higher than other provinces. The DALY standardized rate attributable to high-sodium diets was highest in Xinjiang(4 430.8/100 000), Qinghai(4 422.5/100 000), Tibet(4 021.4/100 000), Shanxi(2 816.6/100 000), and Hebei(2 624.9/100 000). Conclusion: The BOD attributable to high-sodium diets is a serious issue in China, particularly in men and in the northern provinces. Effective measures should be taken in northern provinces to reduce sodium intake.

High resolution P-wave velocity structure beneath Northeastern Tibet from multiscale seismic tomography

NASA Astrophysics Data System (ADS)

Guo, B.; Gao, X.; Chen, J.; Liu, Q.; Li, S.

2016-12-01

The continuing collision of the northward advancing Indian continent with the Eurasia results in the high elevations and thickened Tibetan Plateau. Numerous geologic and geophysical studies engaged in the mechanics of the Tibetan Plateau deformation and uplift. Many seismic experiments were deployed in south and central Tibet, such as INDEPTH and Hi-climb, but very few in northeastern Tibet. Between 2013 and 2015, The China Seismic Array-experiment operated 670 broadband seismic stations with an average station spacing of 35km. This seismic array located in northeastern Tibet and covered the Qilian Mountains, Qaidam Basin, and part of Songpan-Ganzi, Gobi-Alashan, Yangzi, and Ordos. A new multiscale seismic traveltime tomography technique with sparsity constrains were used to map the upper mantle P-wave velocity structure beneath northeastern Tibet. The seismic tomography algorithm employs sparsity constrains on the wavelet representation velocity model via the L1-norm regularization. This algorithm can efficiently deal with the uneven-sampled volume, and give multiscale images of the model. Our preliminary results can be summarized as follows: 1) in the upper mantle down to 200km, significate low-velocity anomalies exist beneath the northeastern Tibet, and slight high-velocity anomalies beneath the Qaidam basin; 2) under Gobi-Alashan, Yangzi, and Ordos, high-velocity anomalies appear to extend to a depth of 250km, this high-velocity may correspond to the lithosphere; 3) there exist relative high-velocity anomalies at depth of 250km-350km underneath north Tibet, which suggests lithospheric delamination; 4) the strong velocity contrast between north Tibet and Yangzi, Gabi-Alashan is visible down to 200km, which implies the north Tibet boundary.

Genetic variability of Echinococcus granulosus based on the mitochondrial 16S ribosomal RNA gene.

PubMed

Wang, Ning; Wang, Jiahai; Hu, Dandan; Zhong, Xiuqin; Jiang, Zhongrong; Yang, Aiguo; Deng, Shijin; Guo, Li; Tsering, Dawa; Wang, Shuxian; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

2015-06-01

Echinococcus granulosus is the etiological agent of cystic echinococcosis, a major zoonotic disease of both humans and animals. In this study, we assessed genetic variability and genetic structure of E. granulosus in the Tibet plateau, using the complete mitochondrial 16 S ribosomal RNA gene for the first time. We collected and sequenced 62 isolates of E. granulosus from 3 populations in the Tibet plateau. A BLAST analysis indicated that 61 isolates belonged to E. granulosus sensu stricto (genotypes G1-G3), while one isolate belonged to E. canadensis (genotype G6). We detected 16 haplotypes with a haplotype network revealing a star-like expansion, with the most common haplotype occupying the center of the network. Haplotype diversity and nucleotide diversity were low, while negative values were observed for Tajima's D and Fu's Fs. AMOVA results and Fst values revealed that the three geographic populations were not genetically differentiated. Our results suggest that a population bottleneck or population expansion has occurred in the past, and that this explains the low genetic variability of E. granulosus in the Tibet Plateau.

Study on the relationship between the lake area variations of Qinghai-Tibetan Plateau and the corresponding climate change in their basins

NASA Astrophysics Data System (ADS)

Guozhuang, Shen; Jingjuan, Liao; Huadong, Guo; Yingkui, Li

2014-03-01

Qinghai-Tibetan Plateau is the largest lake area in China, with a total area of existing lakes of 36,900km2, accounting for 52% of the total lake area of China. Lakes on the Tibetan Plateau play critical roles in the water cycle and ecological and environment systems of the Plateau. The global trend of warming up is increasing obviously, which has led to major changes in the climate conditions in China, even in the world. Whereas, when they analyse the relationship they just use the weather station's recording data, without any spatial analysis of the climate data. Here, we will do some researches on the relationship between the 10 selected lakes' area variation and the corresponding climate change in their drainage basin and discuss how the lakes changes in recent 40 years using the climate data processed using the spatial kriging. Thus, the drainage area can be taken into account and a real relationship can be pointed out. In order to study the relationship, Landsat MSS data, Landsat TM, Landsat ETM images, the topographic map have been collected to extract the variation of lake area. The 131 weather stations climate data, including precipitation, temperature, sun shine duration, evaporation are chosen to study the relationship. After extraction of the area of the lakes, a multivariate statistical analysis method was used to test the relationship between the area of the lakes and the global climate change, including the change of the temperature, the precipitation, and other factors. The variation of lakes in Qinghai-Tibetan Plateau is related to the mean temperature, the precipitation and saturation vapour pressure. But the frozen soil may affect the lake area variation to some extent.

Alkenone temperature and salinity: An evaluation of long chain C37 alkenone in Lake Qinghai, China

NASA Astrophysics Data System (ADS)

Liu, W.; Liu, Z.; Fu, M.; An, Z.

2007-12-01

In recently years, the alkenone unsaturation index (Uk'37=C37:.2/(C37:2+ C37:3)) has been used to reconstructed paleo-temperature for lacustrine sediments. However, few studies have addressed whether the relative abundance of the C37:4 alkenone to the total C37 production (C37:4 percent) can reflect surface salinity changes in lake systems. Here we present the distribution of C37 long chain alkenone of modern lake sediments in Qinghai Lake, Qing-Tibet Plateau, to evaluate significance of abundance change of long chain C37 alkenone as an indicator of lake paleo-enviromental evolution. A group of surface sediments from different locations in the lake have been analyzed in this study. The results of long chain C37 alkenone from 28 surface sediments analyses shown relative abundance of C37:4 alkenone to total C37 production (C37:4 percent) change from 14.5 to 48.6 percent and the abundance of C37:4 alkenone is increasing with decreasing salinity of lake water. For the salinity lake in land, we suggested the relative abundance of C37:4 alkenone in lake sediments may be a indicator of paleo-silinity; We have also found that Uk'37 values are weakly correlated with salinity and C37:4 percent changes, implying that potential minor contributions of temperature and salinity effects to C37:4 percent and Uk'37 respectively cannot be excluded in this study. However, since these contributions are weak, we suggest that the C37:4 percent proxy can be used to reconstruct paleo-salinity changes at a regional scale, especially in lake systems, while Uk'37 remains as a powerful tool for reconstructions of paleo-temperature changes in the lake systems.

[Responses of plant community structure and species composition to warming and N addition in an alpine meadow, northern Tibetan Plateau, China].

PubMed

Zong, Ning; Chai, Xi; Shi, Pei Li; Jiang, Jing; Niu, Ben; Zhang, Xian Zhou; He, Yong Tao

2016-12-01

Global climate warming and increasing nitrogen (N) deposition, as controversial global environmental issues, may distinctly affect the functions and processes of terrestrial ecosystems. It has been reported that the Qinghai-Tibet Plateau has been experiencing significant warming in recent decades, especially in winter. Previous studies have mainly focused on the effects of warming all the year round; however, few studies have tested the effects of winter warming. To investigate the effects of winter warming and N addition on plant community structure and species composition of alpine meadow, long-term N addition and simulated warming experiment was conducted in alpine meadow from 2010 in Damxung, northern Tibet. The experiment consisted of three warming patterns: Year-round warming (YW), winter warming (WW) and control (NW), crossed respectively with five N gradients: 0, 10, 20, 40, 80 kg N·hm -2 ·a -1 . From 2012 to 2014, both warming and N addition significantly affected the total coverage of plant community. Specifically, YW significantly decreased the total coverage of plant community. Without N addition, WW remarkably reduced the vegetation coverage. However, with N addition, the total vegetation coverage gradually increased with the increase of N level. Warming and N addition had different effects on plants from different functional groups. Warming significantly reduced the plant coverage of grasses and sedges, while N addition significantly enhanced the plant coverage of grasses. Regression analyses showed that the total coverage of plant community was positively related to soil water content in vigorous growth stages, indicating that the decrease in soil water content resulted from warming during dry seasons might be the main reason for the decline of total community coverage. As soil moisture in semi-arid alpine meadow is mainly regulated by rainfalls, our results indicated that changes in spatial and temporal patterns of rainfalls under the future climate change scenarios would dramatically influence the vegetation coverage and species composition. Additionally, the effects of increasing atmospheric N deposition on vegetation community might also depend on the change of rainfall patterns.

Some characteristics about marriage and childbearing of Tibetan population in Tibet.

PubMed

Gu, J

1992-02-01

The Tibetans are a major ethnic group in China. Tibet lies in the southwestern section of China at an altitude of 4000 m above sea level. Between 1951-90, its population grew from 1.15 to 2.19 million. Tibetans make up 95% of the population in Tibet. 33.02% of Tibetans =or 15 years old are not married. Males are more likely to be unmarried than females (36.08% vs. 29.98%). The high percentage of unmarrieds in Tibet is 5.3%, 4.7%, and 5.8% higher than the Chinese provinces of Sichuan, Qinghai, and Guizhou, respectively. When the Population Research Institute (PRI) standardized data according to the age structure, the differences between Tibet and Guizhou widened (33.54% vs. 26.8%). The proportion of the married population in Tibet is quite low especially for females. The PRI attributes this lower proportion of married females to the high ratio of spontaneous abortions, high maternal mortality, and high infant and child mortality. Since many young and adult Tibetans become lamas who cannot marry, Buddhism contributes to the high rate of unmarried in Tibet. In 1951, 9.5% (110,000) of the population were lamas. Women can have 1 husband. Tibet has a high mean age at 1st marriage (24.6 years for males and 23.1 years for females). It also has a low sex ratio (97.84, 1982) and age specific sex ratios compared with other major ethnic groups in China. The sex ratio is growing, however (100.13, 1990).

Linking the benefits of ecosystem services to sustainable spatial planning of ecological conservation strategies.

PubMed

Huang, Lin; Cao, Wei; Xu, Xinliang; Fan, Jiangwen; Wang, Junbang

2018-09-15

The maintenance and improvement of ecosystem services on the Tibet Plateau are critical for national ecological security in China and are core objectives of ecological conservation in this region. In this paper, ecosystem service benefits of the Tibet Ecological Conservation Project were comprehensively assessed by estimating and mapping the spatiotemporal variation patterns of critical ecosystem services on the Tibet Plateau from 2000 to 2015. Furthermore, we linked the benefit assessment to the sustainable spatial planning of future ecological conservation strategies. Comparing the 8 years before and after the project, the water retention and carbon sink services of the forest, grassland and wetland ecosystems were slightly increased after the project, and the ecosystem sand fixation service has been steadily enhanced. The increasing forage supply service of grassland significantly reduced the grassland carrying pressure and eased the conflict between grassland and livestock. However, enhanced rainfall erosivity occurred due to increased rainfall, and root-layer soils could not recover in a short period of time, both factors have led to a decline in soil conservation service. The warm and humid climate is beneficial for the restoration of ecosystems on the Tibet Plateau, and the implementation of the Tibet Ecological Conservation Project has had a positive effect on the local improvement of ecosystem services. A new spatial planning strategy for ecological conservation was introduced and aims to establish a comprehensive, nationwide system to protect important natural ecosystems and wildlife, and to promote the sustainable use of natural resources. Copyright © 2018 Elsevier Ltd. All rights reserved.

Climate change and tectonic activity during the early Pliocene Warm Period from the ostracod record at Lake Qinghai, northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Lu, Fengyan; An, Zhisheng; Chang, Hong; Dodson, John; Qiang, Xiaoke; Yan, Hong; Dong, Jibao; Song, Yougui; Fu, Chaofeng; Li, Xiangzhong

2017-05-01

The Early Pliocene Warm Period (EPWP, 5-3 Ma) is sometimes thought to be a useful analogue for a future warmer world, and thus the boundary conditions and drivers of climate in the EPWP may provide valuable lessons for understanding how a future warmer world might unfold. Lake Qinghai is located on the northeastern margin of the Tibetan Plateau (TP) and is affected by both Monsoon climate and Westerlies circulation. It is sensitive to the climate drivers of these systems. Its sediments, accumulated over the Cenozoic period, are a rich source of information for climate, tectonics and environmental changes of the period. We present a high-resolution ostracod record from a Lake Qinghai sediment core with a record of the period 5.10-2.60 Ma, thus covering the EPWP. Ostracods appear at 4.63 Ma and are most abundant until 3.58 Ma, while a body of water was present at the core site. This suggests a phase of humid climate and an intensified Asian Summer Monsoon (ASM), which is consistent with a warmer and wetter climate in the early Pliocene. Within this period the ostracod record shows some variabilities in lake level with deeper periods suggesting more intense ASM compared to those with shallower water. The disappearance of ostracods at 3.58 Ma may provide evidence for the uplift of Qinghai Nanshan (south of Qinghai Lake) since this is when the ASM intensified.

Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services

PubMed Central

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2017-01-01

Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010–2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000–2010 to 2010–2020, especially for three regulation services and aesthetic landscape provision services. PMID:28754029

Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services.

PubMed

Gong, Jian; Li, Jingye; Yang, Jianxin; Li, Shicheng; Tang, Wenwu

2017-07-21

Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010-2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000-2010 to 2010-2020, especially for three regulation services and aesthetic landscape provision services.

Intensified plant N and C pool with more available nitrogen under experimental warming in an alpine meadow ecosystem.

PubMed

Peng, Fei; Xue, Xian; You, Quangang; Xu, Manhou; Chen, Xiang; Guo, Jian; Wang, Tao

2016-12-01

Nitrogen (N) availability is projected to increase in a warming climate. But whether the more available N is immobilized by microbes (thus stimulates soil carbon (C) decomposition), or is absorbed by plants (thus intensifies C uptake) remains unknown in the alpine meadow ecosystem. Infrared heaters were used to simulate climate warming with a paired experimental design. Soil ammonification, nitrification, and net mineralization were obtained by in situ incubation in a permafrost region of the Qinghai-Tibet Plateau (QTP). Available N significantly increased due to the stimulation of net nitrification and mineralization in 0-30 cm soil layer. Microbes immobilized N in the end of growing season in both warming and control plots. The magnitude of immobilized N was lower in the warming plots. The root N concentration significantly reduced, but root N pool intensified due to the significant increase in root biomass in the warming treatment. Our results suggest that a warming-induced increase in biomass is the major N sink and will continue to stimulate plant growth until plant N saturation, which could sustain the positive warming effect on ecosystem productivity.

Impact of overgrazing on the transmission of Echinococcus multilocularis in Tibetan pastoral communities of Sichuan Province, China.

PubMed

Wang, Qian; Xiao, Yong-fu; Vuitton, Dominique A; Schantz, Peter M; Raoul, Francis; Budke, Christine; Campos-Ponce, Maiza; Craig, Philip S; Giraudoux, Patrick

2007-02-05

Overgrazing was assumed to increase the population density of small mammals that are the intermediate hosts of Echinococcus multilocularis, the pathogen of alveolar echinococcosis in the Qinghai Tibet Plateau. This research tested the hypothesis that overgrazing might promote Echinococcus multilocularis transmission through increasing populations of small mammal, intermediate hosts in Tibetan pastoral communities. Grazing practices, small mammal indices and dog Echinococcus multilocularis infection data were collected to analyze the relation between overgrazing and Echinococcus multilocularis transmission using nonparametric tests and multiple stepwise logistic regression. In the investigated area, raising livestock was a key industry. The communal pastures existed and the available forage was deficient for grazing. Open (common) pastures were overgrazed and had higher burrow density of small mammals compared with neighboring fenced (private) pastures; this high overgrazing pressure on the open pastures measured by neighboring fenced area led to higher burrow density of small mammals in open pastures. The median burrow density of small mammals in open pastures was independently associated with nearby canine Echinococcus multilocularis infection (P = 0.003, OR = 1.048). Overgrazing may promote the transmission of Echinococcus multilocularis through increasing the population density of small mammals.

Treeline dynamics in response to climate change in the Min Mountains, southwestern China.

PubMed

Zhao, Zhi-Jiang; Shen, Guo-Zhen; Tan, Liu-Yi; Kang, Dong-Wei; Wang, Meng-Jun; Kang, Wen; Guo, Wen-Xia; Zeppel, Melanie Jb; Yu, Qiang; Li, Jun-Qing

2013-12-01

Abies faxoniana is the dominant plant species of the forest ecosystem on the eastern edge of Qinghai-Tibet Plateau, where the treeline is strongly defined by climate. The tree-ring chronologies and age structure of Abies faxoniana were developed in the treeline ecotones on the northwestern and southeastern aspects of the Min Mountains in the Wanglang Nature Reserve to examine the treeline dynamics of recent decades in response to climate change. On the northwestern aspect, correlation analysis showed that the radial growth was significantly and positively correlated with precipitation in current January and monthly mean temperature in current April, but significantly and negatively correlated with monthly mean temperature in previous August. On the southeastern aspect, the radial growth was significantly negatively correlated with monthly mean temperature in previous July and August. The different responses of radial growth to climatic variability on both the aspects might be mainly due to the micro-environmental conditions. The recruitment benefited from the warm temperature in current April, July and September on the northwestern aspect. The responses of radial growth and recruitment to climatic variability were similar on the northwestern slope. Recruitment was greatly restricted by competition with dense bamboos on the southeastern aspect.

Warming-Induced Decline of Picea crassifolia Growth in the Qilian Mountains in Recent Decades.

PubMed

Yu, Li; Huang, Lei; Shao, Xuemei; Xiao, Fengjing; Wilmking, Martin; Zhang, Yongxiang

2015-01-01

Warming-induced drought has widely affected forest dynamics in most places of the northern hemisphere. In this study, we assessed how climate warming has affected Picea crassifolia (Qinghai spruce) forests using tree growth-climate relationships and the normalized difference vegetation index (NDVI) along the Qilian Mountains, northeastern Tibet Plateau (the main range of Picea crassifolia). Based on the analysis on trees radial growth data from the upper tree line and the regional NDVI data, we identified a pervasive growth decline in recent decades, most likely caused by warming-induced droughts. The drought stress on Picea crassifolia radial growth were expanding from northeast to southwest and the favorable moisture conditions for tree growth were retreating along the identical direction in the study area over the last half century. Compared to the historical drought stress on tree radial growth in the 1920s, recent warming-induced droughts display a longer-lasting stress with a broader spatial distribution on regional forest growth. If the recent warming continues without the effective moisture increasing, then a notable challenge is developed for Picea crassifolia in the Qilian Mountains. Elaborate forest management is necessary to counteract the future risk of climate change effects in this region.

Rhizospheric fungi and their link with the nitrogen-fixing Frankia harbored in host plant Hippophae rhamnoides L.

PubMed

Zhou, Xue; Tian, Lei; Zhang, Jianfeng; Ma, Lina; Li, Xiujun; Tian, Chunjie

2017-12-01

Sea buckthorn (Hippophae rhamnoides L.) is a pioneer plant used for land reclamation and an appropriate material for studying the interactions of symbiotic microorganisms because of its nitrogen-fixing root nodules and mycorrhiza. We used high-throughput sequencing to reveal the diversities and community structures of rhizospheric fungi and their link with nitrogen-fixing Frankia harbored in sea buckthorn collected along an altitude gradient from the Qinghai Tibet Plateau to interior areas. We found that the fungal diversities and compositions varied between different sites. Ascomycota, Basidiomycota, and Zygomycota were the dominant phyla. The distribution of sea buckthorn rhizospheric fungi was driven by both environmental factors and the geographic distance. Among all examined soil characteristics, altitude, AP, and pH were found to have significant (p < 0.05) effect on the rhizospheric fungal community. The rhizospheric fungal communities became more distinct as the distance increased. Moreover, co-inertia analysis identified significant co-structures between Frankia and AMF communities in the rhizosphere of sea buckthorn. We conclude that at the large scale, there are certain linkages between nitrogen-fixing bacteria and the AMF expressed in the distributional pattern. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau].

PubMed

Shen, Shuo

2017-04-04

I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake. I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.

Origin of mitochondrial DNA diversity of domestic yaks

PubMed Central

Guo, Songchang; Savolainen, Peter; Su, Jianping; Zhang, Qian; Qi, Delin; Zhou, Jie; Zhong, Yang; Zhao, Xinquan; Liu, Jianquan

2006-01-01

Background The domestication of plants and animals was extremely important anthropologically. Previous studies have revealed a general tendency for populations of livestock species to include deeply divergent maternal lineages, indicating that they were domesticated in multiple, independent events from genetically discrete wild populations. However, in water buffalo, there are suggestions that a similar deep maternal bifurcation may have originated from a single population. These hypotheses have rarely been rigorously tested because of a lack of sufficient wild samples. To investigate the origin of the domestic yak (Poephagus grunnies), we analyzed 637 bp of maternal inherited mtDNA from 13 wild yaks (including eight wild yaks from a small population in west Qinghai) and 250 domesticated yaks from major herding regions. Results The domestic yak populations had two deeply divergent phylogenetic groups with a divergence time of > 100,000 yrs BP. We here show that haplotypes clustering with two deeply divergent maternal lineages in domesticated yaks occur in a single, small, wild population. This finding suggests that all domestic yaks are derived from a single wild gene pool. However, there is no clear correlation of the mtDNA phylogenetic clades and the 10 morphological types of sampled yaks indicating that the latter diversified recently. Relatively high diversity was found in Qinghai and Tibet around the current wild distribution, in accordance with previous suggestions that the earliest domestications occurred in this region. Conventional molecular clock estimation led to an unrealistic early dating of the start of the domestication. However, Bayesian estimation of the coalescence time allowing a relaxation of the mutation rate are better in agreement with a domestication during the Holocene as supported by archeological records. Conclusion The information gathered here and the previous studies of other animals show that the demographic histories of domestication of livestock species were highly diverse despite the common general feature of deeply divergent maternal lineages. The results further suggest that domestication of local wild prey ungulate animals was a common occurrence during the development of human civilization following the postglacial colonization in different locations of the world, including the high, arid Qinghai-Tibetan Plateau. PMID:16995938

A new approach to very-high-altitude land travel: the train to Lhasa, Tibet.

PubMed

West, John B

2008-12-16

The train from Golmud in Qinghai Province, China, to Lhasa, Tibet, travels for more than 14 hours at an average altitude of 4500 m, the highest point being 5072 m (16,600 ft). Therefore, passengers are potentially exposed to very severe sustained hypoxia. The enterprising solution is to increase the oxygen concentration of the air in the train from 21% to between 24% and 25% by the use of oxygen generators in each passenger car. By increasing the oxygen concentration to 25%, the equivalent altitude is reduced by about 1200 m. The engineering challenge of oxygenating the whole train is immense but has been successfully accomplished. This is an extraordinary innovation in high-altitude transportation.

Northeastward growth of the Tibetan Plateau along the Tibet-Ordos transition zone-revealed from Liupanshan deep seismic reflection profile

NASA Astrophysics Data System (ADS)

Gao, R.; Wang, H.; Guo, X.; Li, W.; Li, H.; Hou, H.; Xiong, X.; Xu, X.; Liang, H.; Li, Q.

2015-12-01

Most previous studies of the Tibetan Plateau have focused on the processes of crustal thickening and subsequent lateral extrusion to account for the outward growth of the plateau. However, lithospheric structure across the tectonic boundaries of the Tibetan Plateau has not yet been fully imaged and, therefore, how geological structures evolved in association with the lateral expansion of the northeastern margin in particular remains unclear. Here, together with interpretation of regional geological and geophysical data, we employ a recently acquired 165 km-long deep seismic reflection image that crosses the Liupan shan (Fig. 1) northeastern flank of the Tibetan Plateau to show that crustal shortening, structural integrity, and topographic relief are strongly correlated. The resulting stratigraphic "architecture" suggests that crustal shortening is a primary driver for plateau uplift and expansion of northeastern Tibet and decoupled crustal deformation owing to differential structural integrity is accommodated during the subsequent northeastward growth of the plateau. Figure 1.Showing the seismic reflection line location and the topographic relief of the northeastern Tibetan Plateau and the western Ordos basin (KF: Kunlun Fault; LP Shan: Liupan Shan; HF: Haiyuan Fault; YTSF: Yangtongshan Fault; NSS-LSF: Niushou Shan-Luoshan Fault)XG Shan: Xiaoguan Shan; YJD: Yanjiadian Diorite; GS: Guanshan Shan; CCP: Caochuanpu; LS Complex: Longshan Complex)

Detection and attribution of vegetation greening trend in China over the last 30 years.

PubMed

Piao, Shilong; Yin, Guodong; Tan, Jianguang; Cheng, Lei; Huang, Mengtian; Li, Yue; Liu, Ronggao; Mao, Jiafu; Myneni, Ranga B; Peng, Shushi; Poulter, Ben; Shi, Xiaoying; Xiao, Zhiqiang; Zeng, Ning; Zeng, ZhenZhong; Wang, Yingping

2015-04-01

The reliable detection and attribution of changes in vegetation growth is a prerequisite for the development of strategies for the sustainable management of ecosystems. This is an extraordinary challenge. To our knowledge, this study is the first to comprehensively detect and attribute a greening trend in China over the last three decades. We use three different satellite-derived Leaf Area Index (LAI) datasets for detection as well as five different process-based ecosystem models for attribution. Rising atmospheric CO2 concentration and nitrogen deposition are identified as the most likely causes of the greening trend in China, explaining 85% and 41% of the average growing-season LAI trend (LAIGS) estimated by satellite datasets (average trend of 0.0070 yr(-1), ranging from 0.0035 yr(-1) to 0.0127 yr(-1)), respectively. The contribution of nitrogen deposition is more clearly seen in southern China than in the north of the country. Models disagree about the contribution of climate change alone to the trend in LAIGS at the country scale (one model shows a significant increasing trend, whereas two others show significant decreasing trends). However, the models generally agree on the negative impacts of climate change in north China and Inner Mongolia and the positive impact in the Qinghai-Xizang plateau. Provincial forest area change tends to be significantly correlated with the trend of LAIGS (P < 0.05), and marginally significantly (P = 0.07) correlated with the residual of LAIGS trend, calculated as the trend observed by satellite minus that estimated by models through considering the effects of climate change, rising CO2 concentration and nitrogen deposition, across different provinces. This result highlights the important role of China's afforestation program in explaining the spatial patterns of trend in vegetation growth. © 2014 John Wiley & Sons Ltd.

Key sources and seasonal dynamics of greenhouse gas fluxes from yak grazing systems on the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, Yang; Yan, Caiyu; Matthew, Cory; Wood, Brennon; Hou, Fujiang

2017-01-01

Greenhouse gas (GHG) emissions from livestock grazing systems are contributing to global warming. To examine the influence of yak grazing systems on GHG fluxes and relationships between GHG fluxes and environmental factors, we measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes over three key seasons in 2012 and 2013 from a range of potential sources, including: alpine meadows, dung patches, manure heaps and yak night pens, on the Qinghai-Tibetan Plateau. We also estimated the total annual global warming potential (GWP, CO2-equivalents) from family farm grazing yaks using our measured results and other published data. In this study, GHG fluxes per unit area from night pens and composting manure heaps were higher than from dung patches and alpine meadows. Increased moisture content and surface temperature of soil and manure were major factors increasing CO2 and CH4 fluxes. High contributions of CH4 and N2O (21.1% and 44.8%, respectively) to the annual total GWP budget (334.2 tonnes) strongly suggest these GHG other than CO2 should not be ignored when estimating GWP from the family farm grazing yaks on the Qinghai-Tibetan Plateau for the purposes of determining national and regional land use policies or compiling global GHG inventories.

Socio-economic burden of parasitic infections in yaks from 1984 to 2017 on Qinghai Tibetan Plateau of China-A review.

PubMed

Li, Kun; Shahzad, Muhammad; Zhang, Hui; Jiang, Xiong; Mehmood, Khalid; Zhao, Xiaodong; Li, Jiakui

2018-07-01

Yak is an important animal for the Tibetans at Qinghai-Tibetan Plateau of China. The burden of parasitic diseases has been a major threat to the health of yaks at this region presenting a considerable socio-economic losses and impact to yak production and local nomads. Keeping in view, we collected the published papers from 1984 to 2017 on major parasitic infections in yaks by electronic literature search from five databases including CNKI, Google, PubMed, Science Direct and Web of Science. The prevalence of Eimeria, Babesia, Theileria, Hypodermosis, Cystic echinococcosis, Alveolar echinococcosis, Toxoplasma gondii, Neospora caninum, Cryptosporidium, Giardia duodenalis, Enterocytozoon bieneusi, Toxocara vitulorum, and Fascioliasis infection in yaks was found to be 48.02%, 13.06%, 36.11%, 59.85%, 16.93%, 0.99%, 20.50%, 5.14%, 10.00%, 3.68%, 4.07%, 22.23% and 28.7% respectively. Data presented are contemplated to enhance our current understanding on the major parasitic diseases of yaks at Qinghai Tibetan plateau, China. The main aim of this effort is to ameliorate the effects of the parasitic burden in this specie; so that, the attempts are made to minimize the incidence of these infections in future to raise the socio-economic levels of local community. Copyright © 2018 Elsevier B.V. All rights reserved.

Responses of alpine grassland on Qinghai-Tibetan plateau to climate warming and permafrost degradation: a modeling perspective

NASA Astrophysics Data System (ADS)

Yi, Shuhua; Wang, Xiaoyun; Qin, Yu; Xiang, Bo; Ding, Yongjian

2014-07-01

Permafrost plays a critical role in soil hydrology. Thus, the degradation of permafrost under warming climate conditions may affect the alpine grassland ecosystem on the Qinghai-Tibetan Plateau. Previous space-for-time studies using plot and basin scales have reached contradictory conclusions. In this study, we applied a process-based ecosystem model (DOS-TEM) with a state-of-the-art permafrost hydrology scheme to examine this issue. Our results showed that 1) the DOS-TEM model could properly simulate the responses of soil thermal and hydrological dynamics and of ecosystem dynamics to climate warming and spatial differences in precipitation; 2) the simulated results were consistent with plot-scale studies showing that warming caused an increase in maximum unfrozen thickness, a reduction in vegetation and soil carbon pools as a whole, and decreases in soil water content, net primary production, and heterotrophic respiration; and 3) the simulated results were also consistent with basin-scale studies showing that the ecosystem responses to warming were different in regions with different combinations of water and energy constraints. Permafrost prevents water from draining into water reservoirs. However, the degradation of permafrost in response to warming is a long-term process that also enhances evapotranspiration. Thus, the degradation of the alpine grassland ecosystem on the Qinghai-Tibetan Plateau (releasing carbon) cannot be mainly attributed to the disappearing waterproofing function of permafrost.

Key sources and seasonal dynamics of greenhouse gas fluxes from yak grazing systems on the Qinghai-Tibetan Plateau

PubMed Central

Liu, Yang; Yan, Caiyu; Matthew, Cory; Wood, Brennon; Hou, Fujiang

2017-01-01

Greenhouse gas (GHG) emissions from livestock grazing systems are contributing to global warming. To examine the influence of yak grazing systems on GHG fluxes and relationships between GHG fluxes and environmental factors, we measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes over three key seasons in 2012 and 2013 from a range of potential sources, including: alpine meadows, dung patches, manure heaps and yak night pens, on the Qinghai-Tibetan Plateau. We also estimated the total annual global warming potential (GWP, CO2-equivalents) from family farm grazing yaks using our measured results and other published data. In this study, GHG fluxes per unit area from night pens and composting manure heaps were higher than from dung patches and alpine meadows. Increased moisture content and surface temperature of soil and manure were major factors increasing CO2 and CH4 fluxes. High contributions of CH4 and N2O (21.1% and 44.8%, respectively) to the annual total GWP budget (334.2 tonnes) strongly suggest these GHG other than CO2 should not be ignored when estimating GWP from the family farm grazing yaks on the Qinghai-Tibetan Plateau for the purposes of determining national and regional land use policies or compiling global GHG inventories. PMID:28106070

Key sources and seasonal dynamics of greenhouse gas fluxes from yak grazing systems on the Qinghai-Tibetan Plateau.

PubMed

Liu, Yang; Yan, Caiyu; Matthew, Cory; Wood, Brennon; Hou, Fujiang

2017-01-20

Greenhouse gas (GHG) emissions from livestock grazing systems are contributing to global warming. To examine the influence of yak grazing systems on GHG fluxes and relationships between GHG fluxes and environmental factors, we measured carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) fluxes over three key seasons in 2012 and 2013 from a range of potential sources, including: alpine meadows, dung patches, manure heaps and yak night pens, on the Qinghai-Tibetan Plateau. We also estimated the total annual global warming potential (GWP, CO 2 -equivalents) from family farm grazing yaks using our measured results and other published data. In this study, GHG fluxes per unit area from night pens and composting manure heaps were higher than from dung patches and alpine meadows. Increased moisture content and surface temperature of soil and manure were major factors increasing CO 2 and CH 4 fluxes. High contributions of CH 4 and N 2 O (21.1% and 44.8%, respectively) to the annual total GWP budget (334.2 tonnes) strongly suggest these GHG other than CO 2 should not be ignored when estimating GWP from the family farm grazing yaks on the Qinghai-Tibetan Plateau for the purposes of determining national and regional land use policies or compiling global GHG inventories.

The long-term trends (1982-2006) in vegetation greenness of the alpine ecosystem in the Qinghai-Tibetan Plateau

USGS Publications Warehouse

Zhang, Li; Guo, Huadong; Wang, Cuizhen; Ji, Lei; Li, Jing; Wang, Kun; Dai, Lin

2014-01-01

The increased rate of annual temperature in the Qinghai-Tibetan Plateau exceeded all other areas of the same latitude in recent decades. The influence of the warming climate on the alpine ecosystem of the plateau was distinct. An analysis of alpine vegetation under changes in climatic conditions was conducted in this study. This was done through an examination of vegetation greenness and its relationship with climate variability using the Advanced Very High Resolution Radiometer satellite imagery and climate datasets. Vegetation in the plateau experienced a positive trend in greenness, with 18.0 % of the vegetated areas exhibiting significantly positive trends, which were primarily located in the eastern and southwestern parts of the plateau. In grasslands, 25.8 % of meadows and 14.1 % of steppes exhibited significant upward trends. In contrast, the broadleaf forests experienced a trend of degradation. Temperature, particularly summer temperature, was the primary factor promoting the vegetation growth in the plateau. The wetter and warmer climate in the east contributed to the favorable conditions for vegetation. The alpine meadow was mostly sensitive to temperature, while the steppes were sensitive to both temperature and precipitation. Although a warming climate was expected to be beneficial to vegetation growth in the alpine region, the rising temperature coupled with reduced precipitation in the south did not favor vegetation growth due to low humidity and poor soil moisture conditions.

Insight into NE Tibet expansion from SKS splitting: Missed mid-lower crustal flow in the frontier

NASA Astrophysics Data System (ADS)

Huang, Zhouchuan; Tilmann, Frederik; Xu, Mingjie; Wang, Liangshu; Ding, Zhifeng; Mi, Ning

2017-04-01

Two end member hypotheses for the expansion of the Tibetan plateau focus on either the deformation of the whole lithosphere or ductile flow in the mid-lower crust. Here, we analyse SKS shear-wave splitting at ChinArray stations in NE Tibet. Within the high plateau, the splitting measurements indicate two-layer anisotropy. The upper-layer anisotropy (with NE-SW fast axis) is caused by ductile-flow in the mid-lower crust while the lower-layer anisotropy (with NW-SE fast axis) reflects deformation in the upper mantle. In contrast, near the expansion frontier, the measurements indicate single layer splitting with a NW-SE fast axis that correlates with the strikes of most faults and the trend of the orogen. The results thus suggest different dynamics in the plateau and its NE margin. In the high plateau mid-lower crustal flow plays a dominant role while in the expansion frontier in the NE margin the initial tectonic uplift is induced by crustal thrust faulting.

Electrical conductivity of the plagioclase-NaCl-water system and its implication for the high conductivity anomalies in the mid-lower crust of Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, Ping; Guo, Xinzhuan; Chen, Sibo; Wang, Chao; Yang, Junlong; Zhou, Xingfan

2018-02-01

In order to investigate the origin of the high conductivity anomalies geophysically observed in the mid-lower crust of Tibet Plateau, the electrical conductivity of plagioclase-NaCl-water system was measured at 1.2 GPa and 400-900 K. The relationship between electrical conductivity and temperature follows the Arrhenius law. The bulk conductivity increases with the fluid fraction and salinity, but is almost independent of temperature (activation enthalpy less than 0.1 eV). The conductivity of plagioclase-NaCl-water system is much lower than that of albite-NaCl-water system with similar fluid fraction and salinity, indicating a strong effect of the major mineral phase on the bulk conductivity of the brine-bearing system. The high conductivity anomalies of 10-1 and 100 S/m observed in the mid-lower crust of Tibet Plateau can be explained by the aqueous fluid with a volume fraction of 1 and 9%, respectively, if the fluid salinity is 25%. The anomaly value of 10-1 S/m can be explained by the aqueous fluid with a volume fraction of 6% if the salinity is 10%. In case of Southern Tibet where the heat flow is high, the model of a thin layer of brine-bearing aqueous fluid with a high salinity overlying a thick layer of partial melt is most likely to prevail.

Shear-velocity structure, radial anisotropy and dynamics of the Tibetan crust

NASA Astrophysics Data System (ADS)

Agius, Matthew R.; Lebedev, Sergei

2014-12-01

Geophysical and geological data suggest that Tibetan middle crust is a partially molten, mechanically weak layer, but it is debated whether this low-viscosity layer is present beneath the entire plateau, what its properties are, how it deforms, and what role it has played in the plateau's evolution. Broad-band seismic surface waves yield resolution in the entire depth range of the Tibetan crust and can be used to constrain its shear-wave velocity structure (indicative of crustal composition, temperature and partial melting) and radial anisotropy (indicative of the patterns of deformation). We measured Love- and Rayleigh-wave phase-velocity curves in broad period ranges (up to 7-200 s) for a few tens of pairs and groups of stations across Tibet, combining, in each case, hundreds of interstation measurements, made with cross-correlation and waveform-inversion methods. Shear-velocity profiles were then determined by extensive series of non-linear inversions of the data, designed to constrain the depth-dependent ranges of isotropic-average shear speeds and radial anisotropy. Shear wave speeds within the Tibetan middle crust are anomalously low and, also, show strong lateral variations across the plateau. The lowest mid-crustal shear speeds are found in the north and west of the plateau (˜3.1-3.2 km s-1), within a pronounced low-velocity zone. In southeastern Tibet, crustal shear wave speeds increase gradually towards southeast, whereas in the north, the change across the Kunlun Fault is relatively sharp. The lateral variations of shear speeds within the crust are indicative of those in temperature. A mid-crustal temperature of 800 °C, reported previously, can account for the low shear velocities across Lhasa. In the north, the temperature is higher and exceeds the solidus, resulting in partial melting that we estimate at 3-6 per cent. Strong radial anisotropy is required by the data in western-central Tibet (>5 per cent) but not in northeastern Tibet. The amplitude of radial anisotropy in the crust does not correlate with isotropic-average shear speed (and, by inference, with crustal rock viscosity) or with surface elevation. Instead, radial anisotropy is related to the deformation pattern and is the strongest in regions experiencing extension (crustal flattening), as noted previously. The growth of Tibet by the addition of Indian crustal rocks into its crust from the south is reflected in the higher crustal seismic velocities (and, thus, lower temperatures) in the southern compared to northern parts of the plateau (more recently added rocks having had less time to undergo radioactive heating within the thickened Tibetan crust). Gravity-driven flattening-the basic cause of extension and normal faulting in the southern, western and central Tibet-is evidenced by pervasive radial anisotropy in the middle crust beneath the regions undergoing extension; the overall eastward flow of the crust is directed by the boundaries and motions of the lithospheric blocks that surround Tibet.

Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

PubMed

Chen, Xiaoqiu; An, Shuai; Inouye, David W; Schwartz, Mark D

2015-10-01

Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth and carbon balance responses to global climate change on the world's roof should integrate both temperature and snowfall variations. © 2015 John Wiley & Sons Ltd.

The Impact of Afforestation on Soil Organic Carbon Sequestration on the Qinghai Plateau, China

PubMed Central

Shi, Sheng-wei; Han, Peng-fei; Zhang, Ping; Ding, Fan; Ma, Cheng-lin

2015-01-01

Afforestation, the conversion of non-forested land into forest, is widespread in China. However, the dynamics of soil organic carbon (SOC) after afforestation are not well understood, especially in plateau climate zones. For a total of 48 shrub- and/or tree-dominated afforestation sites on the Qinghai Plateau, Northwestern China, post-afforestation changes in SOC, total nitrogen (TN), the carbon-to-nitrogen ratio (C/N) and soil bulk density (BD) were investigated to a soil depth of 60 cm using the paired-plots method. SOC and TN accumulated at rates of 138.2 g C m-2 yr-1 and 4.6 g N m-2 yr-1, respectively, in shrub-dominated afforestation sites and at rates of 113.3 g C m-2 yr--1 and 6.7 g N m-2yr-1, respectively, in tree-dominated afforestation sites. Soil BD was slightly reduced in all layers in the shrub-dominated afforestation plots, and significantly reduced in soil layers from 0–40cm in the tree-dominated afforestation plots. The C/N ratio was higher in afforested sites relative to the reference sites. SOC accumulation was closely related to TN accumulation following afforestation, and the inclusion of N-fixing species in tree-dominated afforestation sites additionally increased the soil accumulation capacity for SOC (p < 0.05). Multiple regression models including the age of an afforestation plot and total number of plant species explained 75% of the variation in relative SOC content change at depth of 0–20 cm, in tree-dominated afforestation sites. We conclude that afforestation on the Qinghai Plateau is associated with great capability of SOC and TN sequestration. This study improves our understanding of the mechanisms underlying SOC and TN accumulation in a plateau climate, and provides evidence on the C sequestration potentials associated with forestry projects in China. PMID:25706724

The impact of afforestation on soil organic carbon sequestration on the Qinghai Plateau, China.

PubMed

Shi, Sheng-wei; Han, Peng-fei; Zhang, Ping; Ding, Fan; Ma, Cheng-lin

2015-01-01

Afforestation, the conversion of non-forested land into forest, is widespread in China. However, the dynamics of soil organic carbon (SOC) after afforestation are not well understood, especially in plateau climate zones. For a total of 48 shrub- and/or tree-dominated afforestation sites on the Qinghai Plateau, Northwestern China, post-afforestation changes in SOC, total nitrogen (TN), the carbon-to-nitrogen ratio (C/N) and soil bulk density (BD) were investigated to a soil depth of 60 cm using the paired-plots method. SOC and TN accumulated at rates of 138.2 g C m(-2) yr(-1) and 4.6 g N m(-2) yr(-1), respectively, in shrub-dominated afforestation sites and at rates of 113.3 g C m(-2) yr(-1) and 6.7 g N m(-2) yr(-1), respectively, in tree-dominated afforestation sites. Soil BD was slightly reduced in all layers in the shrub-dominated afforestation plots, and significantly reduced in soil layers from 0-40cm in the tree-dominated afforestation plots. The C/N ratio was higher in afforested sites relative to the reference sites. SOC accumulation was closely related to TN accumulation following afforestation, and the inclusion of N-fixing species in tree-dominated afforestation sites additionally increased the soil accumulation capacity for SOC (p < 0.05). Multiple regression models including the age of an afforestation plot and total number of plant species explained 75% of the variation in relative SOC content change at depth of 0-20 cm, in tree-dominated afforestation sites. We conclude that afforestation on the Qinghai Plateau is associated with great capability of SOC and TN sequestration. This study improves our understanding of the mechanisms underlying SOC and TN accumulation in a plateau climate, and provides evidence on the C sequestration potentials associated with forestry projects in China.

Climate-driven changes in grassland vegetation, snow cover, and lake water of the Qinghai Lake basin

NASA Astrophysics Data System (ADS)

Wang, Xuelu; Liang, Tiangang; Xie, Hongjie; Huang, Xiaodong; Lin, Huilong

2016-07-01

Qinghai Lake basin and the lake have undergone significant changes in recent decades. We examine MODIS-derived grassland vegetation and snow cover of the Qinghai Lake basin and their relations with climate parameters during 2001 to 2010. Results show: (1) temperature and precipitation of the Qinghai Lake basin increased while evaporation decreased; (2) most of the grassland areas improved due to increased temperature and growing season precipitation; (3) weak relations between snow cover and precipitation/vegetation; (4) a significantly negative correlation between lake area and temperature (r=-0.9, p<0.05) and (5) a positive relation between lake level (lake-level difference) and temperature (precipitation). Compared with Namco Lake (located in the inner Tibetan Plateau) where the primary water source of lake level increases was the accelerated melt of glacier/perennial snow cover in the lake basin, for the Qinghai Lake, however, it was the increased precipitation. Increased precipitation explained the improvement of vegetation cover in the Qinghai Lake basin, while accelerated melt of glacier/perennial snow cover was responsible for the degradation of vegetation cover in Namco Lake basin. These results suggest different responses to the similar warming climate: improved (degraded) ecological condition and productive capacity of the Qinghai Lake basin (Namco Lake basin).

Molecular identification of Echinococcus species from eastern and southern Qinghai, China, based on the mitochondrial cox1 gene.

PubMed

Ma, Junying; Wang, Hu; Lin, Gonghua; Craig, Philip S; Ito, Akira; Cai, Zhenyuan; Zhang, Tongzuo; Han, Xiumin; Ma, Xiao; Zhang, Jingxiao; Liu, Yufang; Zhao, Yanmei; Wang, Yongshun

2012-07-01

The Qinghai-Tibetan Plateau (QTP, in western China), which is the largest and highest plateau on Earth, is a highly epidemic region for Echinococcus spp. We collected 70 Echinococcus samples from humans, dogs, sheep, yaks, plateau pikas, and voles in eastern and southern Qinghai and genotyped them using the mitochondrial DNA marker cytochrome oxidase subunit I gene and maximum parsimony and Bayesian reconstruction methods. Based on the 792-bp sequence matrix, we recorded 124 variable sites, of which, 115 were parsimony-informative. Thirty-four haplotypes (H1-H34) were detected, of which H1-H15, H16-H17, and H18-H34 belonged to Echinococcus shiquicus, Echinococcus multilocularis, and Echinococcus granulosus, respectively. Within 26 human isolates, three were identified as E. multilocularis and 23 were E. granulosus. We also detected a dual infection case in a dog with E. multilocularis and E. granulosus. The intraspecific haplotype (Hd ± SD) and nucleotide (Nd ± SD) diversity of E. shiquicus (0.947 ± 0.021; 0.00441 ± 0.00062) was higher than that for E. granulosus (0.896 ± 0.038; 0.00221 ± 0.00031) and E. multilocularis (0.286 ± 0.196; 0.00036 ± 0.00025). Moreover, the haplotype network of E. shiquicus showed a radial feature rather than a divergent feature in a previous study, indicating this species in the QTP has also evolved with bottleneck effects.

Regional danger assessment of Debris flow and its engineering mitigation practice in Sichuan-Tibet highway

NASA Astrophysics Data System (ADS)

Su, Pengcheng; Sun, Zhengchao; li, Yong

2017-04-01

Luding-Kangding highway cross the eastern edge of Qinghai-Tibet Plateau where belong to the most deep canyon area of plateau and mountains in western Sichuan with high mountain and steep slope. This area belongs to the intersection among Xianshuihe, Longmenshan and Anninghe fault zones which are best known in Sichuan province. In the region, seismic intensity is with high frequency and strength, new tectonic movement is strong, rock is cracked, there are much loose solid materials. Debris flow disaster is well developed under the multiple effects of the earthquake, strong rainfall and human activity which poses a great threat to the local people's life and property security. So this paper chooses Kangding and LuDing as the study area to do the debris flow hazard assessment through the in-depth analysis of development characteristics and formation mechanism of debris flow. Which can provide important evidence for local disaster assessment and early warning forecast. It also has the important scientific significance and practical value to safeguard the people's life and property safety and the security implementation of the national major project. In this article, occurrence mechanism of debris flow disasters in the study area is explored, factor of evaluation with high impact to debris flow hazards is identified, the database of initial evaluation factors is made by the evaluation unit of basin. The factors with high impact to hazards occurrence are selected by using the stepwise regression method of logistic regression model, at the same time the factors with low impact are eliminated, then the hazard evaluation factor system of debris flow is determined in the study area. Then every factors of evaluation factor system are quantified, and the weights of all evaluation factors are determined by using the analysis of stepwise regression. The debris flows hazard assessment and regionalization of all the whole study area are achieved eventually after establishing the hazard assessment model. In this paper, regional debris flows hazard assessment method with strong universality and reliable evaluation result is presented. The whole study area is divided into 1674 units by automatically extracting and artificial identification, and then 11 factors are selected as the initial assessment factors of debris flow hazard assessment in the study area. The factors of the evaluation index system are quantified using the method of standardized watershed unit amount ratio. The relationship between debris flow occurrence and each evaluation factor is simulated using logistic regression model. The weights of evaluation factors are determined, and the model of debris flows hazard assessment is established in the study area. Danger assessment result of debris flow was applied in line optimization and engineering disaster reduction of Sichuan-Tibet highway (section of Luding-Kangding).

Locomotive implication of a Pliocene three-toed horse skeleton from Tibet and its paleo-altimetry significance.

PubMed

Deng, Tao; Li, Qiang; Tseng, Zhijie Jack; Takeuchi, Gary T; Wang, Yang; Xie, Guangpu; Wang, Shiqi; Hou, Sukuan; Wang, Xiaoming

2012-05-08

The Tibetan Plateau is the youngest and highest plateau on Earth, and its elevation reaches one-third of the height of the troposphere, with profound dynamic and thermal effects on atmospheric circulation and climate. The uplift of the Tibetan Plateau was an important factor of global climate change during the late Cenozoic and strongly influenced the development of the Asian monsoon system. However, there have been heated debates about the history and process of Tibetan Plateau uplift, especially the paleo-altimetry in different geological ages. Here we report a well-preserved skeleton of a 4.6 million-y-old three-toed horse (Hipparion zandaense) from the Zanda Basin, southwestern Tibet. Morphological features indicate that H. zandaense was a cursorial horse that lived in alpine steppe habitats. Because this open landscape would be situated above the timberline on the steep southern margin of the Tibetan Plateau, the elevation of the Zanda Basin at 4.6 Ma was estimated to be ∼4,000 m above sea level using an adjustment to the paleo-temperature in the middle Pliocene, as well as comparison with modern vegetation vertical zones. Thus, we conclude that the southwestern Tibetan Plateau achieved the present-day elevation in the mid-Pliocene.

Changes in litter quality induced by nutrient addition alter litter decomposition in an alpine meadow on the Qinghai-Tibet Plateau

PubMed Central

Zhu, Wenyan; Wang, Jinzhou; Zhang, Zhenhua; Ren, Fei; Chen, Litong; He, Jin-Sheng

2016-01-01

The effects of nitrogen (N) and phosphorus (P) addition on litter decomposition are poorly understood in Tibetan alpine meadows. Leaf litter was collected from plots within a factorial N × P addition experiment and allowed to decompose over 708 days in an unfertilized plot to determine the effects of N and/or P addition on litter decomposition. Results showed that nutrient addition significantly affected initial P and P-related biochemical properties of litter from all four species. However, the responses of litter N and N-related biochemical properties to nutrient addition were quite species-specific. Litter C decomposition and N release were species-specific. However, N and P addition significantly affected litter P release. Ratios of Hemicellulose + Cellulose to N and P were significantly related to litter C decomposition; C:N ratio was a determinant of litter N release; and C:P and (Hemicellulose + Cellulose):P controlled litter P release. Overall, litter C decomposition was controlled by litter quality of different plant species, and strongly affected by P addition. Increasing N availability is likely to affect litter C decomposition more indirectly by shifting plant species composition than directly by improving litter quality, and may accelerate N and P cycles, but shift the ecosystem to P limitation. PMID:27694948

The role of East Asian monsoon system in shaping population divergence and dynamics of a constructive desert shrub Reaumuria soongarica

PubMed Central

Yin, Hengxia; Yan, Xia; Shi, Yong; Qian, Chaoju; Li, Zhonghu; Zhang, Wen; Wang, Lirong; Li, Yi; Li, Xiaoze; Chen, Guoxiong; Li, Xinrong; Nevo, Eviatar; Ma, Xiao-Fei

2015-01-01

Both of the uplift of Qinghai-Tibet Plateau (QTP) and the development of East Asian monsoon system (EAMS) could have comprehensively impacted the formation and evolution of Arid Central Asia (ACA). To understand how desert plants endemic to ACA responded to these two factors, we profiled the historical population dynamics and distribution range shift of a constructive desert shrub Reaumuria soongarica (Tamaricaceae) based on species wide investigation of sequence variation of chloroplast DNA and nuclear ribosomal ITS. Phylogenetic analysis uncovered a deep divergence occurring at ca. 2.96 Mya between the western and eastern lineages of R. soongarica, and ecological niche modeling analysis strongly supported that the monsoonal climate could have fragmented its habitats in both glacial and interglacial periods and impelled its intraspecific divergence. Additionally, the population from the east monsoonal zone expanded rapidly, suggesting that the local monsoonal climate significantly impacted its population dynamics. The isolation by distance tests supported strong maternal gene flow along the direction of the East Asian winter monsoon, whose intensification induced the genetic admixture along the latitudinal populations of R. soongarica. Our results presented a new case that the development of EAMS had prominently impacted the intraspecific divergence and population dynamics of this desert plant. PMID:26510579

Spatiotemporal evolution of Calophaca (fabaceae) reveals multiple dispersals in central Asian mountains.

PubMed

Zhang, Ming-Li; Wen, Zhi-Bin; Fritsch, Peter W; Sanderson, Stewart C

2015-01-01

The Central Asian flora plays a significant role in Eurasia and the Northern Hemisphere. Calophaca, a member of this flora, includes eight currently recognized species, and is centered in Central Asia, with some taxa extending into adjacent areas. A phylogenetic analysis of the genus utilizing nuclear ribosomal ITS and plastid trnS-trnG and rbcL sequences was carried out in order to confirm its taxonomic status and reconstruct its evolutionary history. We employed BEAST Bayesian inference for dating, and S-DIVA and BBM for ancestral area reconstruction, to study its spatiotemporal evolution. Our results show that Calophacais monophyletic and nested within Caragana. The divergence time of Calophaca is estimated at ca. 8.0 Ma, most likely driven by global cooling and aridification, influenced by rapid uplift of the Qinghai Tibet Plateau margins. According to ancestral area reconstructions, the genus most likely originated in the Pamir Mountains, a global biodiversity hotspot and hypothesized Tertiary refugium of many Central Asian plant lineages. Dispersals from this location are inferred to the western Tianshan Mountains, then northward to the Tarbagatai Range, eastward to East Asia, and westward to the Caucasus, Russia, and Europe. The spatiotemporal evolution of Calophaca provides a case contributing to an understanding of the flora and biodiversity of the Central Asian mountains and adjacent regions.

[Spatiotemporal variations of natural wetland CH4 emissions over China under future climate change].

PubMed

Liu, Jian-gong; Zhu, Qiu-an; Shen, Yan; Yang, Yan-zheng; Luo, Yun-peng; Peng, Chang-hui

2015-11-01

Based on a new process-based model, TRIPLEX-GHG, this paper analyzed the spatio-temporal variations of natural wetland CH4 emissions over China under different future climate change scenarios. When natural wetland distributions were fixed, the amount of CH4 emissions from natural wetland ecosystem over China would increase by 32.0%, 55.3% and 90.8% by the end of 21st century under three representative concentration pathways (RCPs) scenarios, RCP2. 6, RCP4.5 and RCP8.5, respectively, compared with the current level. Southern China would have higher CH4 emissions compared to that from central and northern China. Besides, there would be relatively low emission fluxes in western China while relatively high emission fluxes in eastern China. Spatially, the areas with relatively high CH4 emission fluxes would be concentrated in the middle-lower reaches of the Yangtze River, the Northeast and the coasts of the Pearl River. In the future, most natural wetlands would emit more CH4 for RCP4.5 and RCP8.5 than that of 2005. However, under RCP2.6 scenario, the increasing trend would be curbed and CH4 emissions (especially from the Qinghai-Tibet Plateau) begin to decrease in the late 21st century.

InSAR analysis of surface deformation over permafrost to estimate active layer thickness based on one-dimensional heat transfer model of soils

PubMed Central

Li, Zhiwei; Zhao, Rong; Hu, Jun; Wen, Lianxing; Feng, Guangcai; Zhang, Zeyu; Wang, Qijie

2015-01-01

This paper presents a novel method to estimate active layer thickness (ALT) over permafrost based on InSAR (Interferometric Synthetic Aperture Radar) observation and the heat transfer model of soils. The time lags between the periodic feature of InSAR-observed surface deformation over permafrost and the meteorologically recorded temperatures are assumed to be the time intervals that the temperature maximum to diffuse from the ground surface downward to the bottom of the active layer. By exploiting the time lags and the one-dimensional heat transfer model of soils, we estimate the ALTs. Using the frozen soil region in southern Qinghai-Tibet Plateau (QTP) as examples, we provided a conceptual demonstration of the estimation of the InSAR pixel-wise ALTs. In the case study, the ALTs are ranging from 1.02 to 3.14 m and with an average of 1.95 m. The results are compatible with those sparse ALT observations/estimations by traditional methods, while with extraordinary high spatial resolution at pixel level (~40 meter). The presented method is simple, and can potentially be used for deriving high-resolution ALTs in other remote areas similar to QTP, where only sparse observations are available now. PMID:26480892

InSAR analysis of surface deformation over permafrost to estimate active layer thickness based on one-dimensional heat transfer model of soils.

PubMed

Li, Zhiwei; Zhao, Rong; Hu, Jun; Wen, Lianxing; Feng, Guangcai; Zhang, Zeyu; Wang, Qijie

2015-10-20

This paper presents a novel method to estimate active layer thickness (ALT) over permafrost based on InSAR (Interferometric Synthetic Aperture Radar) observation and the heat transfer model of soils. The time lags between the periodic feature of InSAR-observed surface deformation over permafrost and the meteorologically recorded temperatures are assumed to be the time intervals that the temperature maximum to diffuse from the ground surface downward to the bottom of the active layer. By exploiting the time lags and the one-dimensional heat transfer model of soils, we estimate the ALTs. Using the frozen soil region in southern Qinghai-Tibet Plateau (QTP) as examples, we provided a conceptual demonstration of the estimation of the InSAR pixel-wise ALTs. In the case study, the ALTs are ranging from 1.02 to 3.14 m and with an average of 1.95 m. The results are compatible with those sparse ALT observations/estimations by traditional methods, while with extraordinary high spatial resolution at pixel level (~40 meter). The presented method is simple, and can potentially be used for deriving high-resolution ALTs in other remote areas similar to QTP, where only sparse observations are available now.

Gap locations influence the release of carbon, nitrogen and phosphorus in two shrub foliar litter in an alpine fir forest

PubMed Central

He, Wei; Wu, Fuzhong; Yang, Wanqin; Zhang, Danju; Xu, Zhenfeng; Tan, Bo; Zhao, Yeyi; Justine, Meta Francis

2016-01-01

Gap formation favors the growth of understory plants and affects the decomposition process of plant debris inside and outside of gaps. Little information is available regarding how bioelement release from shrub litter is affected by gap formation during critical periods. The release of carbon (C), nitrogen (N), and phosphorus (P) in the foliar litter of Fargesia nitida and Salix paraplesia in response to gap locations was determined in an alpine forest of the eastern Qinghai-Tibet Plateau via a 2-year litter decomposition experiment. The daily release rates of C, N, and P increased from the closed canopy to the gap centers during the two winters, the two later growing seasons and the entire 2 years, whereas this trend was reversed during the two early growing seasons. The pairwise ratios among C, N, and P converged as the litter decomposition proceeded. Compared with the closed canopy, the gap centers displayed higher C:P and N:P ratio but a lower C:N ratio as the decomposition proceeded. Alpine forest gaps accelerate the release of C, N, and P in decomposing shrub litter, implying that reduced snow cover resulting from vanishing gaps may inhibit the release of these elements in alpine forests. PMID:26906762

Flexural bending of southern Tibet in a retro foreland setting

PubMed Central

Wang, Erchie; Kamp, Peter J. J.; Xu, Ganqing; Hodges, Kip V.; Meng, Kai; Chen, Lin; Wang, Gang; Luo, Hui

2015-01-01

The highest elevation of the Tibetan Plateau, lying 5,700 m above sea level, occurs within the part of the Lhasa block immediately north of the India-Tibet suture zone (Yarlung Zangbo suture zone, YZSZ), being 700 m higher than the maximum elevation of more northern parts of the plateau. Various mechanisms have been proposed to explain this differentially higher topography and the rock uplift that led to it, invoking crustal compression or extension. Here we present the results of structural investigations along the length of the high elevation belt and suture zone, which rather indicate flexural bending of the southern margin of the Lhasa block (Gangdese magmatic belt) and occurrence of an adjacent foreland basin (Kailas Basin), both elements resulting from supra-crustal loading of the Lhasa block by the Zangbo Complex (Indian plate rocks) via the Great Counter Thrust. Hence we interpret the differential elevation of the southern margin of the plateau as due originally to uplift of a forebulge in a retro foreland setting modified by subsequent processes. Identification of this flexural deformation has implications for early evolution of the India-Tibet continental collision zone, implying an initial (Late Oligocene) symmetrical architecture that subsequently transitioned into the present asymmetrical wedge architecture. PMID:26174578

Thickening the outer margins of the Tibetan Plateau: The role of crustal shortening

NASA Astrophysics Data System (ADS)

Lease, R. O.; Burbank, D. W.

2012-12-01

One of the most direct consequences of the collision of two buoyant continents is large-scale crustal thickening that results in the upward and outward growth of high terrain. As the stronger Indian continent has collided with weaker Asia over at least the past 50 Myr, widespread crustal thickening has occurred over an area that is approximately 2.5 million km^2 at present. The resultant Tibetan crust is the thickest observed on Earth today with an average thickness of 65 km and a maximum that may reach 90 km in places. The mechanisms by which Tibetan crust has thickened, however, as well as the timing and distribution of these mechanisms across the plateau, remain debatable. Two of the most popular mechanisms for thickening the crust beneath the margins of the Tibetan Plateau are: 1) pure shear with faulting and folding in the upper crust and horizontal shortening below; and 2) flow and inflation of lower or middle crust without significant shortening of the upper crust. To help discriminate between the relative contributions of these two mechanisms, well-constrained estimates of upper crustal shortening are needed. Here we document the Cenozoic shortening budget across the northeastern Tibetan Plateau margin near 36°N 102.5°E with several 100- to 145-km-long balanced cross sections. Thermochronological and magnetostratigraphic data indicate that modest NNE-SSW shortening began in middle Eocene time, shortly after initial India-Asia collision. Accelerated east-west shortening, however, did not commence until ~35 Myr later. A five-fold acceleration in shortening rates in middle Miocene-to-Recent time accounts for more than half of the total Cenozoic crustal shortening and thickening in this region. Overall, the balanced cross sections indicate 11 ± 2 % east-west shortening since middle Miocene time, and ~9 ± 2 % NNE-SSW shortening between middle Eocene and middle Miocene times. Given the present-day crustal thickness of 56 ± 4 km in northeastern Tibet, crustal restorations that remove Cenozoic shortening suggest that the northeastern Tibetan crust was 45 ± 5 km thick prior to India-Asia continental collision. This pre-collision thickness estimate is equivalent to average continental crustal thicknesses both adjacent to the Tibetan plateau (44 ± 4 km) and globally (41 ± 6 km) and suggests that pure shear alone may account for Cenozoic crustal thickening in northeastern Tibet, obviating the need for lower crustal flow. Furthermore, a growing number of balanced cross sections across the margins of the Tibetan Plateau document Cenozoic shortening sufficient to generate modern crustal thicknesses: in northern Tibet [Yin et al., 2007; 2008a; 2008b], eastern Tibet [Hubbard et al., 2009; 2010], and northeastern Tibet [this work]. Collectively, these similar findings suggest that lower crustal flow is either unnecessary to account for Cenozoic crustal thickening beneath the outer margins of the Tibetan Plateau or, alternatively, has a more restricted role than originally proposed.

O3, SO2, NO2, and UVB measurements in Beijing and Baseline Station of northwestern part of China

NASA Technical Reports Server (NTRS)

Guo, Song; Zhou, Xiuji; Zhang, Xiachun

1994-01-01

A MKII Brewer ozone spectrometer was used in Beijing from Oct. 1990 to June 1991 to measure O3, SO2 and UVB radiation. And since Nov. 1991 a new MKIV Brewer spectrometer, which can take the measurements of O3, SO2, NO2 and UVB radiation, has been set up in Beijing. The MKII Brewer spectrometer was moved to Qinghai baseline station which is on the Qinghai-tibetean plateau in the northwestern part of China. Both the data in Beijing and Qinghai baseline station has been analyzed and some results will be shown here along with the ozone profiles botained through the Umkehr program given by AES of Canada for the Brewer ozone spectrometer.

Summer moisture changes in the Lake Qinghai area on the northeastern Tibetan Plateau recorded from a meadow section over the past 8400 yrs

NASA Astrophysics Data System (ADS)

Li, Xiangzhong; Liu, Xiangjun; He, Yuxin; Liu, Weiguo; Zhou, Xin; Wang, Zheng

2018-02-01

Holocene climatic and environmental changes on the northeastern Tibetan Plateau (TP) have been widely discussed based on the climatic records from sedimentary cores. However, differences in the reconstructed climatic history from various studies in this region still exist, probably due to influence of climatic proxies from multiple factors and the chronological uncertainties in lacustrine sediments. Here we present records of terrestrial plant δ13C, soil color and total organic carbon content over the past 8400 years from a well-dated meadow section on the northeastern TP. The terrestrial plant δ13C value serves as a good summer precipitation/moisture indicator in the studied region. Soil color property and TOC content are also able to disentangle the moisture evolution history. All the data show much wet climates at 8400-7400 cal yr BP, dry climates at 7400-6000 cal yr BP and then wet conditions with fluctuation at 6000-3200 cal yr BP. Late Holocene moisture appears to be comparable with moist conditions from 6000 to 3200 cal yr BP. By further comparing the climatic variations in the Lake Qinghai area with records of the reconstructed summer temperature and the Asian Monsoon precipitation, we believe that the pattern of moisture/precipitation evolution in the Lake Qinghai area was not completely consistent with regions around Lake Qinghai, probably due to complicated interaction between the East Asian Summer Monsoon and the Indian Summer Monsoon.

Genetic Convergence in the Adaptation of Dogs and Humans to the High-Altitude Environment of the Tibetan Plateau

PubMed Central

Wang, Guo-Dong; Fan, Ruo-Xi; Zhai, Weiwei; Liu, Fei; Wang, Lu; Zhong, Li; Wu, Hong; Yang, He-Chuan; Wu, Shi-Fang; Zhu, Chun-Ling; Li, Yan; Gao, Yun; Ge, Ri-Li; Wu, Chung-I; Zhang, Ya-Ping

2014-01-01

The high-altitude hypoxic environment represents one of the most extreme challenges for mammals. Previous studies of humans on the Tibetan plateau and in the Andes Mountains have identified statistical signatures of selection in different sets of loci. Here, we first measured the hemoglobin levels in village dogs from Tibet and those from Chinese lowlands. We found that the hemoglobin levels are very similar between the two groups, suggesting that Tibetan dogs might share similar adaptive strategies as the Tibetan people. Through a whole-genome sequencing approach, we have identified EPAS1 and HBB as candidate genes for the hypoxic adaptation on the Tibetan plateau. The population genetic analysis shows a significant convergence between humans and dogs in Tibet. The similarities in the sets of loci that exhibit putative signatures of selection and the hemoglobin levels between humans and dogs of the same environment, but not between human populations in different regions, suggests an extraordinary landscape of convergent evolution between human beings and their best friend on the Tibetan plateau. PMID:25091388

Sedimentary archaeal amoA gene abundance reflects historic nutrient level and salinity fluctuations in Qinghai Lake, Tibetan Plateau

PubMed Central

Yang, Jian; Jiang, Hongchen; Dong, Hailiang; Hou, Weiguo; Li, Gaoyuan; Wu, Geng

2015-01-01

Integration of DNA derived from ancient phototrophs with their characteristic lipid biomarkers has been successfully employed to reconstruct paleoenvironmental conditions. However, it is poorly known that whether the DNA and lipids of microbial functional aerobes (such as ammonia-oxidizing archaea: AOA) can be used for reconstructing past environmental conditions. Here we identify and quantify the AOA amoA genes (encoding the alpha subunit of ammonia monooxygenases) preserved in a 5.8-m sediment core (spanning the last 18,500 years) from Qinghai Lake. Parallel analyses revealed that low amoA gene abundance corresponded to high total organic carbon (TOC) and salinity, while high amoA gene abundance corresponded to low TOC and salinity. In the Qinghai Lake region, TOC can serve as an indicator of paleo-productivity and paleo-precipitation, which is related to historic nutrient input and salinity. So our data suggest that temporal variation of AOA amoA gene abundance preserved in Qinghai Lake sediment may reflect the variations of nutrient level and salinity throughout the late Pleistocene and Holocene in the Qinghai Lake region. PMID:26666501

Holocene moisture and East Asian summer monsoon evolution in the northeastern Tibetan Plateau recorded by Lake Qinghai and its environs: A review of conflicting proxies

NASA Astrophysics Data System (ADS)

Chen, Fahu; Wu, Duo; Chen, Jianhui; Zhou, Aifeng; Yu, Junqing; Shen, Ji; Wang, Sumin; Huang, Xiaozhong

2016-12-01

Climatic and environmental changes in the northeastern Tibetan Plateau are controlled by the Asian summer monsoon (ASM) and the westerlies, two key circulation components of the global climate system which directly affect a large human population and associated ecosystems in eastern Asia. During the past few decades, a series of Holocene palaeoclimatic records have been obtained from sediment cores from Lake Qinghai and from various other geological archives in the surrounding area of the northeastern Tibetan Plateau. However, because of uncertainties regarding the sediment chronologies and the climatic significance of the proxies used, the nature of Holocene climatic changes in the region remains unclear and even controversial. Here we review all major classes of the published data from drilled cores from Lake Qinghai, as well as other evidence from lakes and aeolian deposits from surrounding areas, in order to reconstruct changes in moisture patterns and possible summer monsoon evolution in the area during the Holocene. Combining the results of moisture and precipitation proxies such as vegetation history, pollen-based precipitation reconstruction, aeolian activity, lake water depth/lake level changes, salinity and sediment redness, we conclude that moisture and precipitation began to increase in the early Holocene, reached their maximum during the middle Holocene, and decreased during the late Holocene - similar to the pattern of the East Asian summer monsoon (EASM) in northern China. It is clear that the region experienced a relatively dry climate and weak EASM during the early Holocene, as indicated by relatively low tree pollen percentages and fluctuating pollen concentrations; generally low lake levels of Lake Qinghai and the adjacent Lake Hurleg and Lake Toson in the Qaidam Basin; and widely distributed aeolian sand deposition in the Lake Qinghai Basin and the nearby Gonghe Basin to the south, and in the eastern Qaidam Basin to the west. We argue that the ostracod δ18O record, which is widely used as a proxy of effective moisture and summer monsoon intensity in lake sediments, at least in Lake Qinghai, and which exhibits light values in the early Holocene and heavier values thereafter, cannot be used to reflect the strength of the EASM or the intensity of monsoon precipitation - as is also the case for leaf wax δ2H records. Rather, we argue that as is the case of the Chinese speleothem δ18O record, which also is often interpreted as an EASM proxy, it reflects variation in the δ18O of precipitation. Overall, we suggest that the EASM significantly affected precipitation in the northeastern Tibetan Plateau during the Holocene; and that it increased in strength during the early Holocene, reached a maximum during the middle Holocene and decreased during the late Holocene.

Hydrological controls on Chemical weathering in the Jinsha River draining the southeastern Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Zhong, Jun; Li, Siliang; Yue, Fujun; Ding, Hu

2016-04-01

The geochemistry of the riverine waters could provide an insight in understanding the surface processes, such as chemical weathering and carbon cycle. As the headwater of Chanjiang (Yangtze) River, Jinsha River flows on the southestern Qinhai-Tibet Plateau at high altitute (from 1000m to 4600m) above the major areas of human impact and carries important information on this erosive region. In spite of being impacted by monsoonal climate and with significant variations of discharge, the temporal variations of compositions of main ions and chemical weathering of Jinsha River are rarely documented. In this study, a systematic investigation on the seasonal and episodic water geochemistry (major ions and δ13CDIC) of the outlet of Jinsha River basin were carried out with the purpose of 1) characterizing temporal variations of aqueous geochemistry and its controlling factors, 2) quantifying rock weathering and associated CO2 consumption rates, and 3) exploring the impact of hydrological controls on chemical weathering of the Jinsha River Basin. The results show that the concentrations of Ca, Mg, HCO3 and NO3 are generally decreased during monsoon season, while that of Cl, Na, SO4, K are relative higher in monsoon season than in dry season, which may be mainly caused by hydrological condition, i.e., with increased runoff, more surficial evaporate dissolved water and salt lake water of the Basin flow into the river. Moreover, due to increased contribution of soil CO2and fast decomposition of organic matters, δ13CDIC in the high-flow period has more negative values than in low-flow period, and shows a negative relation with the concentration of DOC. An increasing of Ca concentrations was found with shift of the δ13CDIC values, positively, indicating the precipitation might be occured. Meanwhile, the dissolution of gypsum and anhydrite might enhance the calcium precipition. The forward model results show that the weathering rates of silicate and carbonate as well as that of related CO2 consumption have a positive relation with water discharge, highlighting the hydrological controls on chemical weathering and CO2 consumption rates, which should be considered in the future study in river basins impacted by monsoon climate. This work was supported by The China National Science Fund for Outstanding Young Scholars (Grant No. 41422303).

Taxonomy of the genus Metolinus Cameron (Coleoptera, Staphylinidae, Staphylininae, Xantholinini) from China with description of three new species

PubMed Central

Zhou, Yu-Lingzi; Zhou, Hong-Zhang

2011-01-01

Abstract This paper studies the taxonomy of the genus Metolinus Cameron, 1920 (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) from China and describes three new species: Metolinus xizangensis sp. n. from Xizang (Tibet), Metolinus emarginatus sp. n. fromSichuan, and Metolinus binarius sp. n. from Yunnan. The Chinese fauna of the genus is thus increased to 8 species in total. A key to eight Chinese species is provided. Female genital segments and other important morphological characters are illustrated in line drawings for the new species as well as Metolinus shanicus Bordoni, 2002 and Metolinus gardneri (Cameron, 1945). The text also provides color plates with habitus photographs and a map to show the species’ geographical distribution pattern. The type specimens of the new species are deposited in Institute of Zoology, the Chinese Academy of Sciences (IZ-CAS). PMID:21976988

Holocene aeolian activity in the Gonghe Basin, north-eastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Stauch, Georg; Lai, Zhongping; Lehmkuhl, Frank; Schulte, Philipp

2016-04-01

The Gonghe Basin is located on the north-eastern edge of Tibetan Plateau and has a mean altitude of 3000 m asl. With a size of 20.000 km² it is the largest intramontane Basin on the north-eastern Plateau. The well-studied Qinghai Basin is situated north of the Basin, while the drier central Plateau is further south-west. Previous research indicated an early onset of the aeolian accumulation in the Qinghai Basin at around 18 ka while in the areas further to the south-west aeolian archives date back only to the beginning of the Holocene. First new OSL ages from aeolian sand and loess indicate a intermediate timing of the aeolian accumulation in the Gonghe Basin at the transition from the late glacial to the Holocene. Late glacial and early Holocene ages of aeolian sediments were hitherto associated with wetter climate conditions caused by the strengthening of the Asian summer monsoon. Higher moisture availability resulted in an increased vegetation cover, leading to the permanent stabilization of the aeolian sediments. Under glacial climate conditions a constant remobilization of the sediments can be assumed. The new OSL ages from the Gonghe Basin indicate a progressive shift of the monsoonal strength in westward directions during the late glacial until the early Holocene.

Climate Change-Induced Range Expansion of a Subterranean Rodent: Implications for Rangeland Management in Qinghai-Tibetan Plateau

PubMed Central

Su, Junhu; Aryal, Achyut; Nan, Zhibiao; Ji, Weihong

2015-01-01

Disturbances, both human-induced and natural, may re-shape ecosystems by influencing their composition, structure, and functional processes. Plateau zokor (Eospalax baileyi) is a typical subterranean rodent endemic to Qinghai-Tibetan Plateau (QTP), which are considered ecosystem engineers influencing the alpine ecosystem function. It is also regarded as a pest aggravating the degradation of overgrazed grassland and subject to regular control in QTP since 1950s. Climate change has been predicted in this region but little research exists exploring its impact on such subterranean rodent populations. Using plateau zokor as a model, through maximum entropy niche-based modeling (Maxent) and sustainable habitat models, we investigate zokor habitat dynamics driven by the future climate scenarios. Our models project that zokor suitable habitat will increase by 6.25% in 2050 in QTP. The predication indicated more threats in terms of grassland degradation as zokor suitable habitat will increase in 2050. Distribution of zokors will shift much more in their southern range with lower elevation compare to northern range with higher elevation. The estimated distance of shift ranges from 1 km to 94 km from current distribution. Grassland management should take into account such predictions in order to design mitigation measures to prevent further grassland degradation in QTP under climate change scenarios. PMID:26406891

Diurnal characteristics of ecosystem respiration of alpine meadow on the Qinghai-Tibetan Plateau: implications for carbon budget estimation.

PubMed

Qin, Yu; Yi, Shuhua

2013-01-01

Accurately estimating daily mean ecosystem respiration rate (Re) is important for understanding how ecosystem carbon budgets will respond to climate change. Usually, daily mean Re is represented by measurement using static chamber on alpine meadow ecosystems from 9:00 to 11:00 h a.m. local time directly. In the present study, however, we found that the calculated daily mean Re from 9:00 to 11:00 h a.m. local time was significantly higher than that from 0:00 to 23:30 h local time in an alpine meadow site, which might be caused by special climate condition on the Qinghai-Tibetan Plateau. Our results indicated that the calculated daily mean Re from 9:00 to 11:00 h a.m. local time cannot be used to represent daily mean Re directly.

Holocene record of eolian activity from Genggahai Lake, northeastern Qinghai-Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Qiang, Mingrui; Liu, Yingying; Jin, Yanxiang; Song, Lei; Huang, Xiangtong; Chen, Fahu

2014-01-01

The history of dust emission and eolian activity in dust source areas remains unclear due to the scarcity of geological archives. Grain-size data from Genggahai Lake on the northeastern Qinghai-Tibetan Plateau show that sand-sized particles in the lake sediments were transported primarily by strong winds to the lake and therefore can be used as a proxy for eolian activity. Eolian activity was weak from 10.3 to 6.3 ka, which may be a response to increased vegetation cover due to the strengthened Asian summer monsoon. In contrast, eolian activity occurred episodically when the summer monsoon weakened. The abrupt, intense sand deposition events are likely to have resulted from strong wind regimes, in turn linked to cooling events in the North Atlantic. Our results suggest that changes in atmospheric circulation patterns may have strongly affected the moisture balance and wind strength in the dust source area and hence dust emissions.

Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014.

PubMed

Ma, Jun; Xiao, Xiangming; Zhang, Yao; Doughty, Russell; Chen, Bangqian; Zhao, Bin

2018-10-15

Accurately estimating spatial-temporal patterns of gross primary production (GPP) is important for the global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatial-temporal dynamics of GPP. However, the accuracy assessment of GPP simulations from LUE models at both spatial and temporal scales remains a challenge. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images with 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPP VPM ) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPP VPM and SIF data over a single year (2010) and multiple years (2007-2014) in most areas of China. GPP VPM is also significantly positive correlated with GOME-2 SIF (R 2  > 0.43) spatially for seasonal scales. However, poor consistency was detected between GPP VPM and SIF data at yearly scale. GPP dynamic trends have high spatial-temporal variation in China during 2007-2014. Temperature, leaf area index (LAI), and precipitation are the most important factors influence GPP VPM in the regions of East Qinghai-Tibet Plateau, Loss Plateau, and Southwestern China, respectively. The results of this study indicate that GPP VPM is temporally and spatially in line with GOME-2 SIF data, and space-borne SIF data have great potential for evaluating LUE-based GPP models. Copyright © 2018 Elsevier B.V. All rights reserved.

A Review of Geophysical Constraints on the Deep Structure of the Tibetan Plateau, the Himalaya and the Karakoram, and their Tectonic Implications

NASA Astrophysics Data System (ADS)

Molnar, P.

1988-09-01

The Tibetan Plateau, the Himalaya and the Karakoram are the most spectacular consequences of the collision of the Indian subcontinent with the rest of Eurasia in Cainozoic time. Accordingly, the deep structures beneath them provide constraints on both the tectonic history of the region and on the dynamic processes that have created these structures. The dispersion of seismic surface waves requires that the crust beneath Tibet be thick: nowhere less than 50 km, at least 65 km, in most areas, but less than 80 km in all areas that have been studied. Wide-angle reflections of P-waves from explosive sources in southern Tibet corroborate the existence of a thick crust but also imply the existence of marked lateral variations in that thickness, or in the velocity structure of the crust. Thus isostatic compensation occurs largely by an Airy-type mechanism, unlike that, for instance, of the Basin and Range Province of western North America where a hot upper mantle buoys up a thin crust. The P-wave and S-wave velocities in the uppermost mantle of most of Tibet are relatively high and typical of those of Precambrian shields and stable platforms: Vp = 8.1 km s-1 or higher, and Vs≈ 4.7 km s-1. Travel times and waveforms of S-waves passing through the uppermost mantle of much of Tibet, however, require a much lower average velocity in the uppermost mantle than that of the Indian, or other, shields. They indicate a thick low-velocity zone in the upper mantle beneath Tibet, reminiscent of tectonically active regions. These data rule out a shield structure beneath northern Tibet and suggest that if such a structure does underlie part of the plateau, it does so only beneath the southern part. Lateral variations in the upper-mantle structure of Tibet are apparent from differences in travel times of S-waves from earthquakes in different parts of Tibet, in the attenuation of short-period phases, Pn and Sn, that propagate through the uppermost mantle of Tibet, and in surface-wave dispersion for different paths. The notably lower velocities and the greater attenuation in the mantle of north--central Tibet than elsewhere imply higher temperatures there and are consistent with the occurrence of active and young volcanism in roughly the same area. Surface-wave dispersion across north--central Tibet also requires a thinner crust in that area than in most of the plateau. Consequently the relatively uniform height of the plateau implies that isostatic compensation in the north--central part of Tibet occurs partly because the density of the relatively hot material in the upper mantle is lower than that elsewhere beneath Tibet, the mechanism envisioned by Pratt. Several seismological studies provide evidence consistent with a continuity of the Indian Shield, and its cold thick lithosphere, beneath the Himalaya. Fault-plane solutions and focal depths of the majority of moderate earthquakes in the Himalaya are consistent with their occurring on the top surface of the gently flexed, intact Indian plate that has underthrust the Lesser Himalaya roughly 80-100 km or more. P-waves from explosions in southern Tibet and recorded in Nepal can be interpreted as wide-angle reflections from this fault zone. P-wave delays across the Tarbela network in Pakistan from distant earthquakes indicate a gentle dip of the Moho beneath the array without pronounced later variations in upper-mantle structure. High Pn and Sn velocities beneath the Himalaya and normal to early S-wave arrival times from Himalayan earthquakes recorded at teleseismic distances are consistent with Himalaya being underlain by the same structure that underlies India. Results from explosion seismology indicate an increase in crustal thickness from the Indo--Gangetic Plain across the Himalaya to southern Tibet, but Hirn, Lepine, Sapin and their co-workers inferred that the depth of the Moho does not increase smoothly northward, as it would if the Indian Shield had been underthrust coherently beneath the Himalaya. They interpreted wide-angle reflections as evidence for steps in the Moho displaced from one another on southward-dipping faults. Although I cannot disprove this interpretation, I think that one can recognize a sequence of signals on their wide-angle reflection profiles that could be wide-angle reflections from a northward-dipping Moho. Gravity anomalies across the Himalaya show that both the Indo--Gangetic Plain and the Himalaya are not in local isostatic equilibrium. A mass deficit beneath the plain is apparently caused by the flexure of the Indian Shield and by the low density of the sedimentary rock in the basin formed by the flexure. The mass excess in the Himalaya seems to be partly supported by the strength of the Indian plate, for which the flexural rigidity is particularly large. An increase in the Bouguer gravity gradient from about 1 mGal km-1 (1 mGal = 10-3 cm s-2) over the Indo--Gangetic Plain to 2 mGal km-1 over the Himalaya implies a marked steepening of the Moho, and therefore a greater flexure of the Indian plate, beneath the Himalaya. This implies a northward decrease in the flexural rigidity of the part of the Indian plate underlying the range. Nevertheless, calculations of deflections of elastic plates with different flexural rigidities and flexed by the weight of the Himalaya show larger deflections and yield more negative gravity anomalies than are observed. Thus, some other force, besides the flexural strength of the plate, must contribute to the support of the range. A bending moment applied to the end of the Indian plate could flex the plate up beneath the range and provide the needed support. The source of this moment might be gravity acting on the mantle portion of the subducting Indian continental lithosphere with much or all of the crust detached from it. Seismological studies of the Karakoram are consistent with its being underlain by particularly cold material in the upper mantle. Intermediate-depth earthquakes occur between depths of 70 and 100 km but apparently do not define a zone of subducted oceanic lithosphere. Rayleigh-wave phase velocities are particularly high for paths across this area and imply high shear wave velocities in the upper mantle. Isostatic gravity anomalies indicate a marked low of 70 mGal over the Karakoram, which could result from a slightly thickened crust pulled down by the sinking of cold material beneath it. Geophysical constraints on the structure of Tibet, the Himalaya and the Karakoram are consistent with a dynamic uppermost mantle that includes first, the plunging of cold material into the asthenosphere beneath southern Tibet and the Karakoram, as the Indian plate slides beneath the Himalaya, and second, an upwelling of hot material beneath north--central Tibet. The structure is too poorly resolved to require such dynamic flow, but the existence for both a hot uppermost mantle beneath north--central Tibet and a relatively cold uppermost mantle beneath southern Tibet and the Karakoram seem to be required. Both group and phase velocities of Rayleigh waves and Love waves are delayed along paths crossing Tibet. The low velocities require a crustal thickness in excess of 50 km, and for most regions in excess of 60 km. Crustal thicknesses in excess of 80 km can be ruled out for all paths studied, and for most of Tibet, a crustal thickness of 65-70 km seems required. Clear evidence for lateral heterogeneity beneath Tibet is provided not only by body waves (discussed below) but also by surface waves (Brandon & Romanowicz 1986), which show an area of lower uppermost shear-wave velocity and thinner crust in north--central Tibet than elsewhere in the plateau. These variations might explain the differences in group velocities measured by different workers, and the different structures that they deduced, but if so, they also render the regionalization of surface-wave dispersion into arbitrary tectonic provinces risky. Although Rayleigh-wave phase velocities can resolve large differences in upper-mantle velocities for regions the size of Tibet, constraints on these velocities are best derived from body waves. Thus, with the exceptions of Brandon & Romanowicz's (1986) detailed investigation of north--central Tibet, the study of southernmost Tibet by Jobert et al. (1985) and that of Romanowicz (1982) for the northeasternmost part of the plateau, I do not think that surface waves have placed an important bound on the velocity in the upper mantle beneath Tibet. The seismic data are broadly consistent with partial melting of the uppermost mantle of north--central Tibet, where recent volcanism has been observed. Correspondingly, there is no suggestion of such low velocities, and such high temperatures, in the mantle elsewhere beneath Tibet, for which late-Cainozoic volcanism has not been reported. The results are also consistent with a slightly thinner crust in north--central Tibet than farther south, suggesting that both Airy and Pratt isostasy share compensation for north--central Tibet's great height. Finally, the average shear-wave velocity in the upper mantle of southern Tibet seems to be higher than that in northern Tibet, but neither is the degree of difference well determined, nor is the location of the transition from one to the other well mapped.

Ecosystem Carbon Storage in Alpine Grassland on the Qinghai Plateau

PubMed Central

Liu, Shuli; Zhang, Fawei; Du, Yangong; Guo, Xiaowei; Lin, Li; Li, Yikang; Li, Qian; Cao, Guangmin

2016-01-01

The alpine grassland ecosystem can sequester a large quantity of carbon, yet its significance remains controversial owing to large uncertainties in the relative contributions of climate factors and grazing intensity. In this study we surveyed 115 sites to measure ecosystem carbon storage (both biomass and soil) in alpine grassland over the Qinghai Plateau during the peak growing season in 2011 and 2012. Our results revealed three key findings. (1) Total biomass carbon density ranged from 0.04 for alpine steppe to 2.80 kg C m-2 for alpine meadow. Median soil organic carbon (SOC) density was estimated to be 16.43 kg C m-2 in alpine grassland. Total ecosystem carbon density varied across sites and grassland types, from 1.95 to 28.56 kg C m-2. (2) Based on the median estimate, the total carbon storage of alpine grassland on the Qinghai Plateau was 5.14 Pg, of which 94% (4.85 Pg) was soil organic carbon. (3) Overall, we found that ecosystem carbon density was affected by both climate and grazing, but to different extents. Temperature and precipitation interaction significantly affected AGB carbon density in winter pasture, BGB carbon density in alpine meadow, and SOC density in alpine steppe. On the other hand, grazing intensity affected AGB carbon density in summer pasture, SOC density in alpine meadow and ecosystem carbon density in alpine grassland. Our results indicate that grazing intensity was the primary contributing factor controlling carbon storage at the sites tested and should be the primary consideration when accurately estimating the carbon storage in alpine grassland. PMID:27494253

Ecosystem Carbon Storage in Alpine Grassland on the Qinghai Plateau.

PubMed

Liu, Shuli; Zhang, Fawei; Du, Yangong; Guo, Xiaowei; Lin, Li; Li, Yikang; Li, Qian; Cao, Guangmin

2016-01-01

The alpine grassland ecosystem can sequester a large quantity of carbon, yet its significance remains controversial owing to large uncertainties in the relative contributions of climate factors and grazing intensity. In this study we surveyed 115 sites to measure ecosystem carbon storage (both biomass and soil) in alpine grassland over the Qinghai Plateau during the peak growing season in 2011 and 2012. Our results revealed three key findings. (1) Total biomass carbon density ranged from 0.04 for alpine steppe to 2.80 kg C m-2 for alpine meadow. Median soil organic carbon (SOC) density was estimated to be 16.43 kg C m-2 in alpine grassland. Total ecosystem carbon density varied across sites and grassland types, from 1.95 to 28.56 kg C m-2. (2) Based on the median estimate, the total carbon storage of alpine grassland on the Qinghai Plateau was 5.14 Pg, of which 94% (4.85 Pg) was soil organic carbon. (3) Overall, we found that ecosystem carbon density was affected by both climate and grazing, but to different extents. Temperature and precipitation interaction significantly affected AGB carbon density in winter pasture, BGB carbon density in alpine meadow, and SOC density in alpine steppe. On the other hand, grazing intensity affected AGB carbon density in summer pasture, SOC density in alpine meadow and ecosystem carbon density in alpine grassland. Our results indicate that grazing intensity was the primary contributing factor controlling carbon storage at the sites tested and should be the primary consideration when accurately estimating the carbon storage in alpine grassland.

Using the Electromagnetic Induction Method to Connect Spatial Vegetation Distributions with Soil Water and Salinity Dynamics on Steppe Grassland

NASA Astrophysics Data System (ADS)

Jiang, Z.; Li, X.; Wu, H.

2014-12-01

In arid and semi-arid areas, plant growth and productivity are obviously affected by soil water and salinity. But it is not easy to acquire the spatial and temporal dynamics of soil water and salinity by traditional field methods because of the heterogeneity in their patterns. Electromagnetic induction (EMI), for its rapid character, can provide a useful way to solve this problem. Grassland dominated by Achnatherum splendens is an important ecosystem near the Qinghai-Lake watershed on the Qinghai-Tibet Plateau in northwestern China. EMI surveys were conducted for electrical conductivity (ECa) at an intermediate habitat scale (a 60×60 m experimental area) of A. splendens steppe for 18 times (one day only for one time) during the 2013 growing season. And twenty sampling points were established for the collection of soil samples for soil water and salinity, which were used for calibration of ECa. In addition, plant species, biomass and spatial patterns of vegetation were also sampled. The results showed that ECa maps exhibited distinctly spatial differences because of variations in soil moisture. And soil water was the main factor to drive salinity patterns, which in turn affected ECa values. Moreover, soil water and salinity could explain 82.8% of ECa changes due to there was a significant correlation (P<0.01) between ECa, soil water and salinity. Furthermore, with higher ECa values closer to A. splendens patches at the experimental site, patterns of ECa images showed clearly temporal stability, which were extremely corresponding with the spatial pattern of vegetation. A. splendens patches that accumulated infiltrating water and salinity and thus changed long-term soil properties, which were considered as "reservoirs" and were deemed responsible for the temporal stability of ECa images. Hence, EMI could be an indicator to locate areas of decreasing or increasing of water and to reveal soil water and salinity dynamics through repeated ECa surveys.

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau.

PubMed

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-11-01

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages.

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau

PubMed Central

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-01-01

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages. PMID:24340197

Millennial slip-rates along the eastern Kunlun fault and rapid evolution of channel morphology in the yellow river headwaters, northeastern Tibet, China

NASA Astrophysics Data System (ADS)

Harkins, Nathan W.

A mechanical description of the interplay between ongoing crustal deformation and topographic evolution within the Tibetan Plateau remains outstanding, and thus our ability to describe the mechanisms responsible for the creation of this and other continental plateaus is limited. In this work, we employ a multidisciplinary approach to investigate the Quaternary record of active tectonism and coeval topographic evolution in the northeastern Tibetan Plateau. Fluvial channel topographic data paired with geochronologically calibrated measures of erosion rate reveal a headward migrating wave of dramatically accelerated incision rates in the headwaters of the Yellow River, which drains a large portion of northeastern Tibet. This transient increase in incision is likely driven by downstream base-level changes along the plateau margin and is superimposed onto a broad region of higher erosion rates confined to the plateau itself, within the Anyemaqen Shan (mountains). The Kunlun fault, one of the major active strike-slip faults of Tibet, trends through the Anyemaqen Shan. Using a careful approach towards quantifying millennial slip-rates along this fault zone based on the age of offset landforms, we constrain the Pleistocene kinematics of the eastern portion of the Kunlun fault and link this deformation to tectonically-driven erosion in the Anyemaqen Shan. Consideration of the age and morphology of fluvial terraces offset by the fault both highlights uncertainties associated with slip-rate determinations and allow more confident quantification of the allowable range of slip-rates at sites that take advantage of these features. Several new slip-rate determinations from this study at select locations corroborate a small number of previous determinations to identify an eastward decreasing slip-rate gradient and termination of the Kunlun fault within the Anyemaqen Shan. Existing geodetic data reveals a similar pattern of eastward-decreasing distributed shear across the fault zone. The spatial coincidence of tectonically driven erosion in the Anyemaqen Shan with the slip-rate gradient and termination the Kunlun fault implies that the crust of the northeastern plateau has the ability to accumulate regionally distributed permanent strain. Therefore, traditional 'rigid-body' rotation type descriptions of Tibetan Plateau kinematics fail to describe deformation on the northeastern plateau.

Radiation and diversification within the Ligularia-Cremanthodium-Parasenecio complex (Asteraceae) triggered by uplift of the Qinghai-Tibetan Plateau.

PubMed

Liu, Jian-Quan; Wang, Yu-Jing; Wang, Ai-Lan; Hideaki, Ohba; Abbott, Richard J

2006-01-01

The Ligularia-Cremanthodium-Parasenecio (L-C-P) complex of the Tussilagininae (Asteraceae: Senecioneae) contains more than 200 species that are endemic to the Qinghai-Tibetan Plateau in eastern Asia. These species are morphologically distinct; however, their relationships appear complex. A phylogenetic analysis of members of the complex and selected taxa of the tribe Senecioneae was conducted using chloroplast (ndhF and trnL-F) and nuclear (ITS) sequences. Phylogenetic trees were constructed from individual and combined datasets of the three different sequences. All analyses suggested that Doronicum, a genus that has been included in the Tussilagininae, should be excluded from this subtribe and placed at the base of the tribe Senecioneae. In addition, the Tussilagininae should be broadly circumscribed to include the Tephroseridinae. Within the expanded Tussilagininae containing all 13 genera occurring in eastern Asia, Tussilago and Petasites diverged early as a separate lineage, while the remaining 11 genera comprise an expanded L-C-P complex clade. We suggest that the L-C-P clade, which is largely unresolved, most likely originated as a consequence of an explosive radiation. The few monophyletic subclades identified in the L-C-P clade with robust support further suggest that some genera of Tussilagininae from eastern Asia require generic re-circumscriptions given the occurrence of subclades containing species of the same genus in different parts of the phylogentic tree due to homoplasy of important morphological characters used to delimit them. Molecular-clock analyses suggest that the explosive radiation of the L-C-P complex occurred mostly within the last 20 million years, which falls well within the period of recent major uplifts of the Qinghai-Tibetan Plateau between the early Miocene to the Pleistocene. It is proposed that significant increases in geological and ecological diversity that accompanied such uplifting, most likely promoted rapid and continuous allopatric speciation in small and isolated populations, and allowed fixation or acquisition of similar morphological characters within unrelated lineages. This phenomenon, possibly combined with interspecific diploid hybridization because of secondary sympatry during relatively stable stages between different uplifts, could be a major cause of high species diversity in the Qinghai-Tibetan Plateau and adjacent areas of eastern Asia.

InSAR observations of low slip rates on the major faults of western Tibet.

PubMed

Wright, Tim J; Parsons, Barry; England, Philip C; Fielding, Eric J

2004-07-09

Two contrasting views of the active deformation of Asia dominate the debate about how continents deform: (i) The deformation is primarily localized on major faults separating crustal blocks or (ii) deformation is distributed throughout the continental lithosphere. In the first model, western Tibet is being extruded eastward between the major faults bounding the region. Surface displacement measurements across the western Tibetan plateau using satellite radar interferometry (InSAR) indicate that slip rates on the Karakoram and Altyn Tagh faults are lower than would be expected for the extrusion model and suggest a significant amount of internal deformation in Tibet.

Iodine isotopes (129I and 127I) in the hydrosphere of Qinghai-Tibet region and South China Sea.

PubMed

Yi, Peng; Chen, Xuegao; Wang, Zixia; Aldahan, Ala; Hou, Xiaolin; Yu, Zhongbo

2018-06-14

The radioactive isotope 129 I, with a half-life of 1.57 × 10 7 years, is widely used as a tracer to assess nuclear safety, to track environmental and geological events and to figure out the details of the stable iodine geochemical cycle. This work investigated the 129 I and 127 I distribution in water samples collected from the terrestrial (rivers, lakes and springs) and marine water systems (estuary and sea) in China. The measured 129 I concentrations of (1-51) × 10 6 atoms/L and 129 I/ 127 I ratios of (0.03-21) × 10 -10 shows the variability of 129 I level in the water systems. The local permafrost and seasonal frozen environment play a key role in groundwater recharge in the Qinghai-Tibet region, which is reflected in the 129 I distribution in surface water. The depth distribution of 129 I in the water column of the South China Sea reflects the effluence of different currents. The results also indicate that the hydrosphere of China contains one to three orders of magnitude less 129 I compared to those reported in Europe. Despite the large distance, the European nuclear fuel reprocessing facilities represent the major source of 129 I in the hydrosphere of China through atmospheric transport. The contribution of the Fukushima nuclear accident to 129 I levels in the hydrosphere of China was negligible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Environmental impact assessment and environmental audit in large-scale public infrastructure construction: the case of the Qinghai-Tibet Railway.

PubMed

He, Guizhen; Zhang, Lei; Lu, Yonglong

2009-09-01

Large-scale public infrastructure projects have featured in China's modernization course since the early 1980s. During the early stages of China's rapid economic development, public attention focused on the economic and social impact of high-profile construction projects. In recent years, however, we have seen a shift in public concern toward the environmental and ecological effects of such projects, and today governments are required to provide valid environmental impact assessments prior to allowing large-scale construction. The official requirement for the monitoring of environmental conditions has led to an increased number of debates in recent years regarding the effectiveness of Environmental Impact Assessments (EIAs) and Governmental Environmental Audits (GEAs) as environmental safeguards in instances of large-scale construction. Although EIA and GEA are conducted by different institutions and have different goals and enforcement potential, these two practices can be closely related in terms of methodology. This article cites the construction of the Qinghai-Tibet Railway as an instance in which EIA and GEA offer complementary approaches to environmental impact management. This study concludes that the GEA approach can serve as an effective follow-up to the EIA and establishes that the EIA lays a base for conducting future GEAs. The relationship that emerges through a study of the Railway's construction calls for more deliberate institutional arrangements and cooperation if the two practices are to be used in concert to optimal effect.

Phylogeography of the Qinghai-Tibetan Plateau endemic Juniperus przewalskii (Cupressaceae) inferred from chloroplast DNA sequence variation.

PubMed

Zhang, Q; Chiang, T Y; George, M; Liu, J Q; Abbott, R J

2005-10-01

The vegetation of the northeast Qinghai-Tibetan Plateau is dominated by alpine meadow and desert-steppe with sparse forests scattered within it. To obtain a better understanding of the phylogeography of one constituent species of the forests in this region, we examined chloroplast trnT-trnF and trnS-trnG sequence variation within Juniperus przewalskii, a key endemic tree species. Sequence data were obtained from 392 trees in 20 populations covering the entire distribution range of the species. Six cpDNA haplotypes were identified. Significant population subdivision was detected (G(ST) = 0.772, N(ST) = 0.834), suggesting low levels of recurrent gene flow among populations and significant phylogeographic structure (N(ST) > G(ST), P < 0.05). Eight of the nine disjunct populations surveyed on the high-elevation northeast plateau were fixed for a single haplotype (A), while the remaining, more westerly population, contained the same haplotype at high frequency together with two low frequency haplotypes (C and F). In contrast, most populations that occurred at lower altitudes at the plateau edge were fixed or nearly fixed for one of two haplotypes, A or E. However, two plateau edge populations had haplotype compositions different from the rest. In one, four haplotypes (A, B, D and E) were present at approximately equivalent frequencies, which might reflect a larger refugium in the area of this population during the last glacial period. Phylogenetic analysis indicated that the most widely distributed haplotype A is not ancestral to other haplotypes. The contrasting phylogeographic structures of the haplotype-rich plateau edge area and the almost haplotype-uniform plateau platform region indicate that the plateau platform was recolonized by J. przewalskii during the most recent postglacial period. This is supported by the findings of a nested clade analysis, which inferred that postglacial range expansion from the plateau edge followed by recent fragmentation is largely responsible for the present-day spatial distribution of cpDNA haplotypes within the species.

Deformation of Tibetan lithosphere and asthenosphere as inferred from broadband surface waves

NASA Astrophysics Data System (ADS)

Agius, Matthew; Lebedev, Sergei

2014-05-01

The numerous seismic stations deployed across Tibet and the surrounding regions in recent years have greatly increased the data coverage across the Plateau. Despite the numerous studies of its crust, however, how the convergence of northward moving India and stable Eurasia is accommodated today is still debated. Regarding the lateral distribution of deformation, end-member models invoke deformation at narrow boundaries between "rigid blocks" and, alternatively, "continuous deformation" with viscous behaviour of the lithosphere. Regarding the vertical distribution of deformation, end-member models include "vertically coherent deformation" within the entire lithospheric thickness, and "channel flow" in which mechanically weak mid-lower crust undergoes flow that is distinctly different from the motions of the (stronger) layers above and below. Broad-band surface waves provide resolving power from the upper crust down to the asthenosphere, for both isotropic-average shear-wave speeds (proxies for composition and temperature) and the radial and azimuthal shear-wave anisotropy (indicative of the patterns of deformation and flow). We measured highly accurate Love- and Rayleigh-wave phase-velocity curves in broad period ranges (5-200 s) for a few tens of pairs and groups of stations across Tibet, combining, in each case, hundreds of inter-station measurements, made with cross-correlation and waveform-inversion methods. Robust shear-velocity profiles were then determined by series of non-linear inversions, yielding depth-dependent ranges of shear speeds and radial anisotropy consistent with the data. Azimuthal anisotropy in the crust and upper mantle was determined by surface-wave tomography and, also, by sub-array analysis targeting the anisotropy amplitude. The Tibetan middle crust is characterised by very low shear-wave speeds, as observed previously, however with strong variations across the plateau. The mid-crustal low-velocity zone, probably indicating partial melt and low viscosity, shows particularly low wave speeds in northern Tibet (3.08-3.43 km/s). The similarity of phase-velocity curves for neighbouring station pairs across large regions within Tibet and the coherent pattern of anisotropy within them suggest that deformation is diffused across broad areas. The maximum extension directions, derived from crustal azimuthal anisotropy, show W-E and NW-SE fast directions in central and eastern Tibet, respectively. The correlation of azimuthal anisotropy with the surface strain indicates that the dominant pattern of deformation in the middle crust is the same as that in the upper crust. Furthermore, the close agreement of anisotropy and the extensional component of the current strain rate field with the traces of sutures implies that the dominant deformation mechanism within the plateau has not changed since the initiation of continental collision and is still governed by the northward push of India. A warm Tibetan lithosphere and asthenosphere lay beneath the north-central and north-eastern plateau. SSW-NNE asthenospheric flow beneath north-eastern Tibet is evidenced by azimuthal anisotropy constrained by our data, with the fast-propagation direction parallel to that of India's plate motion. This suggests that the flow is associated with India's northward subduction beneath the Tibetan lithosphere and asthenosphere under the central and eastern plateau. The distributed, multi-layered azimuthal anisotropy beneath Tibet, with different fast-propagations directions in the crust and asthenospheric mantle, accounts for the complexity of published shear-wave splitting observations.

Lateral variations in the crustal structure of the Indo-Eurasian collision zone

NASA Astrophysics Data System (ADS)

Gilligan, Amy; Priestley, Keith

2018-05-01

The processes involved in continental collisions remain contested, yet knowledge of these processes is crucial to improving our understanding of how some of the most dramatic features on Earth have formed. As the largest and highest orogenic plateau on Earth today, Tibet is an excellent natural laboratory for investigating collisional processes. To understand the development of the Tibetan Plateau we need to understand the crustal structure beneath both Tibet and the Indian Plate. Building on previous work, we measure new group velocity dispersion curves using data from regional earthquakes (4424 paths) and ambient noise data (5696 paths), and use these to obtain new fundamental mode Rayleigh Wave group velocity maps for periods from 5-70 s for a region including Tibet, Pakistan and India. The dense path coverage at the shortest periods, due to the inclusion of ambient noise measurements, allows features of up to 100 km scale to be resolved in some areas of the collision zone, providing one of the highest resolution models of the crust and uppermost mantle across this region. We invert the Rayleigh wave group velocity maps for shear wave velocity structure to 120 km depth and construct a 3D velocity model for the crust and uppermost mantle of the Indo-Eurasian collision zone. We use this 3D model to map the lateral variations in the crust and in the nature of the crust-mantle transition (Moho) across the Indo-Eurasian collision zone. The Moho occurs at lower shear velocities below north eastern Tibet than it does beneath western and southern Tibet and below India. The east-west difference across Tibet is particularly apparent in the elevated velocities observed west of 84° E at depths exceeding 90 km. This suggests that Indian lithosphere underlies the whole of the Plateau in the west, but possibly not in the east. At depths of 20-40 km our crustal model shows the existence of a pervasive mid-crustal low velocity layer (˜10% decrease in velocity, Vs <3.4 km/s) throughout all of Tibet, as well as beneath the Pamirs, but not below India. The thickness of this layer, the lowest velocity in the layer and the degree of velocity reduction vary across the region. Combining our Rayleigh wave observations with previously published Love wave dispersion measurements (Acton et al., 2010), we find that the low velocity layer has a radial anisotropic signature with Vsh > Vsv. The characteristics of the low velocity layer are supportive of deformation occurring through ductile flow in the mid-crust.

Genetic convergence in the adaptation of dogs and humans to the high-altitude environment of the tibetan plateau.

PubMed

Wang, Guo-Dong; Fan, Ruo-Xi; Zhai, Weiwei; Liu, Fei; Wang, Lu; Zhong, Li; Wu, Hong; Yang, He-Chuan; Wu, Shi-Fang; Zhu, Chun-Ling; Li, Yan; Gao, Yun; Ge, Ri-Li; Wu, Chung-I; Zhang, Ya-Ping

2014-08-01

The high-altitude hypoxic environment represents one of the most extreme challenges for mammals. Previous studies of humans on the Tibetan plateau and in the Andes Mountains have identified statistical signatures of selection in different sets of loci. Here, we first measured the hemoglobin levels in village dogs from Tibet and those from Chinese lowlands. We found that the hemoglobin levels are very similar between the two groups, suggesting that Tibetan dogs might share similar adaptive strategies as the Tibetan people. Through a whole-genome sequencing approach, we have identified EPAS1 and HBB as candidate genes for the hypoxic adaptation on the Tibetan plateau. The population genetic analysis shows a significant convergence between humans and dogs in Tibet. The similarities in the sets of loci that exhibit putative signatures of selection and the hemoglobin levels between humans and dogs of the same environment, but not between human populations in different regions, suggests an extraordinary landscape of convergent evolution between human beings and their best friend on the Tibetan plateau. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The Large Scale Tectonic Framework of SE Asia and the Deformation of the lithosphere Beneath Tibet and SW China (Invited)

NASA Astrophysics Data System (ADS)

van der Hilst, R. D.; Huang, H.; Yao, H.

2010-12-01

We summarize results of our seismological studies of the lithosphere beneath Tibet and SW China. Joint analysis of geological, geodetic, and seismological data suggests that the Tibetan plateau formed through interplay between continental collision between India and Asia in the west and ocean floor subduction along the western Pacific island arcs and marginal basins in the east. These dynamic systems combine to facilitate the eastward extrusion of lithospheric material away from central Tibet. Located near the transition of these systems, SE Tibet is a key area for understanding regional seismicity as well as eastward plateau expansion. For a detailed regional study MIT installed an array of 25 three-component, broad band seismometers in Sichuan and Yunnan provinces, SW China. During the same 1-year period Lehigh University operated a 75 station array in east Tibet. Data from these and other nearby arrays have been used in a range of studies of crust and mantle heterogeneity and anisotropy. We focus our presentation on results of two lines of seismological study. First, travel time tomography (Li et al., PEPI 2006, EPSL 2008, JGR 2010) - with hand-picked phase arrivals from recordings at regional arrays, data from over 1,000 stations in China, and the global data base due to Engdahl et al. (BSSA, 1998) - has revealed that structures associated with subduction of the Indian plate beneath the Himalayas vary significantly from west Tibet (where the plate seems to underlie the entire plateau) to east Tibet (where Indian lithosphere seems to have plunged deeper into the mantle). Further east, fast structures appear in the upper mantle transition zone, presumably related to stagnation of slab fragments from westward subduction along Asia’s eastern sea board. Second, surface wave array tomography (Yao et al., GJI 2006, GJI 2008, JGR 2010; Huang et al., GRL 2010), based on ambient noise interferometry and traditional (inter station) dispersion analysis, is used to delineate the 3-D anisotropic structure of the crust and lithospheric mantle at length scales as small as 100 km beneath SE Asia. These inversions revealed (i) the presence of intra-crustal low velocity zones (perhaps bounded by major faults), (ii) a strong correlation between these low velocity zones and radial anisotropy (Vsh faster than Vsv), and (iii) that the pattern of crustal (azimuthal) anisotropy is quite different from that in the deep crust and mantle lithosphere. Furthermore, the spatial relationship with high heat flow, high (electrical) conductivity, and high Poisson’s ratio’s suggests that the crustal zones of low shear velocity are mechanically weak. Collectively, these inferences suggest that deformation is generally not vertically coherent and that (horizontal) ductile flow occurs (at least locally) in the deep crust of SE Tibet. Deformation of the lithosphere in SE Tibet may thus occur through interaction of geological units with and without crustal flow that are separated by major faults.

Lake surface area variation and its responses to climatic change in Yamzhog Yumco Basin, South Tibet during 1970-2010

NASA Astrophysics Data System (ADS)

Zhang, X.; Tian, Y.; Sun, R.

2015-12-01

The research on lake extraction from multi-source and multi-temporal satellite images and the lake size variation can provide reliable method and indispensable information to deepen the understanding about alpine lake changes with the accelerating warming. With field survey experience in the Yamzhog Yumco Basin, South Tibet, the outlines of five lakes (i.e., Yamzhog Yumco, Chen Co, Kongmu Co, Bajiu Co and Puma Yumco) were delineated by the adoption of 42 scenes of satellite images from Landsat, CBERS and HJ from 1970 to 2010, basing on which the responses of alpine lakes to climate change at different timescales were explored. The results are summarized as follows. (1) The seasonal fluctuation of lake surface area was similar with different trend for the five alpine lakes. As for the last 41 years, the annual variation of lake surface area exhibited two kinds of patterns for the five alpine lakes. And the Yamzhog Yumco declined by 9.41%, while the rest four lakes expanded. (2) The responses of alpine lakes to climate change rely on different timescale and water replenishment types. On the one hand, the precipitation change was the predominant driving forces for the seasonal fluctuation and variation trend of lake size, and the rising temperature accounted for the inter-annual lake surface variation. On the other hand, the two kinds of alpine lakes behaviors were well correspondent with the warming temperature over the Qinghai-Tibetan Plateau. The lakes supplied mainly by precipitation shrunk as a result of increased evaporation, and lakes supplied mainly by glacier and snow meltwater, however, expanded because of the remarkable glacier recession. (3) The quantification of hydrological components would hopefully be improved, according to uncertainties analysis, with the adoption of microwave satellite images and higher resolution ones to disclose the interaction mechanism among climate, glacier, and lake in alpine regions.

Teleseismic shear-wave splitting in SE Tibet: Insight into complex crust and upper-mantle deformation

NASA Astrophysics Data System (ADS)

Huang, Zhouchuan; Wang, Liangshu; Xu, Mingjie; Ding, Zhifeng; Wu, Yan; Wang, Pan; Mi, Ning; Yu, Dayong; Li, Hua

2015-12-01

We measured shear-wave splitting of teleseismic XKS phases (i.e., SKS, SKKS and PKS) recorded by more than 300 temporary ChinArray stations in Yunnan of SE Tibet. The first-order pattern of XKS splitting measurements shows that the fast polarization directions (φ) change (at ∼26-27°N) from dominant N-S in the north to E-W in the south. While splitting observations around the eastern Himalayan syntax well reflect anisotropy in the lithosphere under left-lateral shear deformation, the dominant E-W φ to the south of ∼26°N is consistent with the maximum extension in the crust and suggest vertically coherent pure-shear deformation throughout the lithosphere in Yunnan. However, the thin lithosphere (<80 km) could account for only part (<0.7 s) of the observed splitting delay times (δt, 0.9-1.5 s). Anisotropy in the asthenosphere is necessary to explain the NW-SE and nearly E-W φ in these regions. The NE-SW φ can be explained by the counter flow caused by the subduction and subsequent retreat of the Burma slab. The E-W φ is consistent with anisotropy due to the absolute plate motion in SE Tibet and the eastward asthenospheric flow from Tibet to eastern China accompanying the tectonic evolution of the plateau. Our results provide new information on different deformation fields in different layers under SE Tibet, which improves our understanding on the complex geodynamics related to the tectonic uplift and southeastward expansion of Tibetan material under the plateau.

The first fossil brown lacewing from the Miocene of the Tibetan Plateau (Neuroptera, Hemerobiidae)

PubMed Central

Yang, Qiang; Shi, Chaofan; Li, Xiangchuan; Pang, Hong; Ren, Dong

2018-01-01

Abstract A new species of Hemerobiidae, Wesmaelius makarkini Yang, Pang & Ren, sp. n. is described from the Lower Miocene, Garang Formation of Zeku County, Qinghai Province (northeastern Tibetan Plateau), China. The species is assigned to the widely distributed extant genus Wesmaelius Krüger (Hemerobiinae). The species represents the first named fossil of this family from China, which sheds light on the historical distribution of Wesmaelius and early divergences within Hemerobiinae. PMID:29430206

The first fossil brown lacewing from the Miocene of the Tibetan Plateau (Neuroptera, Hemerobiidae).

PubMed

Yang, Qiang; Shi, Chaofan; Li, Xiangchuan; Pang, Hong; Ren, Dong

2018-01-01

A new species of Hemerobiidae, Wesmaelius makarkini Yang, Pang & Ren, sp. n. is described from the Lower Miocene, Garang Formation of Zeku County, Qinghai Province (northeastern Tibetan Plateau), China. The species is assigned to the widely distributed extant genus Wesmaelius Krüger (Hemerobiinae). The species represents the first named fossil of this family from China, which sheds light on the historical distribution of Wesmaelius and early divergences within Hemerobiinae.

Soil organic carbon and total nitrogen pools in permafrost zones of the Qinghai-Tibetan Plateau.

PubMed

Zhao, Lin; Wu, Xiaodong; Wang, Zhiwei; Sheng, Yu; Fang, Hongbing; Zhao, Yonghua; Hu, Guojie; Li, Wangping; Pang, Qiangqiang; Shi, Jianzong; Mo, Bentian; Wang, Qian; Ruan, Xirui; Li, Xiaodong; Ding, Yongjian

2018-02-26

There are several publications related to the soil organic carbon (SOC) on the Qinghai-Tibetan Plateau (QTP). However, most of these reports were from different parts of the plateau with various sampling depth. Here, we present the results from a systematic sampling and analysis of 200 soil pits. Most of the pits were deeper than 2 m from an east-west transect across the plateau. The SOC and total nitrogen (TN) pools of the 148 × 10 4  km 2 , the area of the permafrost zone, for the upper 2 m soils calculated from the vegetation map were estimated to be 17.07 Pg (interquartile range: 11.34-25.33 Pg) and 1.72 Pg (interquartile range: 1.08-2.06 Pg), respectively. We also predicted the distribution of land cover types in 2050 and 2070 using decision tree rules and climate scenarios, and then predicted SOC and TN pools of this region. The results suggested that the SOC and TN pools will decrease in the future. The results not only contribute to the carbon and nitrogen storage and stocks in the permafrost regions as a whole but most importantly, to our knowledge of the possible changes of C and N storage on the QTP in the future.

Carbon Emission from Tibet Plateau Rivers: a Case Study of the Yellow River Headwater Region

NASA Astrophysics Data System (ADS)

Lu, X. X.; Yang, X.; Tian, M. Y.; Su, Y. R.; Ran, L.; Hu, H. Z.; Yu, R. H.

2017-12-01

Global warming will have major impacts on the high-altitude environments, including glacier retreats and permafrost thawing. Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. Study on riverine sediment and carbon fluxes from permafrost thawing and glacial retreat at high latitudes can help to identify the potential hazards of carbon emissions and provide scientific references for formulating climate adaptation strategy. The headwater region of the Yellow River, located in the north eastern Tibetan Plateau, retains a huge amount of organic carbon stored in the widely distributed meadow and steppe soils, which has been and will be affected by climate change. For example, carbon storage in the Ruoergai (Zoige) wetlands surrounded by mountain glaciers and permafrost is estimated at 23.2 Gt, representing a very high percentage of the soil carbon in the entire Tibet Plateau. Global warming will have far-reaching impacts on riverine sediment and carbon fluxes in this region. However, the amount of riverine carbon released by glacier retreat and permafrost thawing has not been well studied in this region. This talk will report our results obtained from 4 rounds of field campaign in the headwater region of the Yellow River, with a focus of the river and stream systems in the Ruoergai peatland and the Anyemaqen glacier. Our preliminary results indicated that riverine carbon emission from the headwater region was much higher than our previous report estimated from water chemistry data. With increase in temperature the rivers in Himalayas and Tibet Plateau are potential carbon source areas.

Spatial patterns of soil n-alkane δD values on the Tibetan Plateau: Implications for monsoon boundaries and paleoelevation reconstructions

NASA Astrophysics Data System (ADS)

Bai, Yan; Fang, Xiaomin; Tian, Qian

2012-10-01

Between 2010 and 2011, this project collected and analyzed forty-nine superficial soil samples, for wax-derivedn-alkaneδD values (δDwax), along a south to north transect of the Tibetan Plateau, from the southern Plateau and Nepalese Himalayas, passing through the Nam Co basin, to Qilian Mountains. Twenty-two paired river water samples were also collected from northeastern Tibet during this period and analyzed forδD (δDRW). The δDRW and δDwaxvalues become progressively more negative northward from ˜27.5°N, and reach a minimum at ˜30.6°N (Nam Co basin). North of the Nam Co basin, to 35°N, isotope values increase, due to increasing contributions from the year-round westerlies and recycled moisture from the Plateau. Relatively high and constantδDwax and δDRW values prevail in areas north of ˜35°N in northeastern Tibet. Results show that these δDwaxvalues vary considerably with location and relate closely to the influences of the summer monsoon and circulation changes. These changes track the spatial variability of isotopes from modern river water and precipitation at large spatial scales. Paleoelevation reconstructions should take into account the impact of mixing between continental and monsoon-derived moisture on the relationships with elevation andδDwax (and linear isotopic lapse rates) for central northeastern Tibet. Based on extended and more sensitive (relative to δ18O) δDwax and δDRW values, we infer that in the past the westerlies reached further south, to the north piedmont of the Nyainqentanglha Range, and that Indian Summer Monsoon moisture pushes across the Tanggula Mountains and approaches the Kunlun Mountains.

Three Dimensional Lithospheric Electrical Structure of the Tibetan Plateau as Revealed by SinoProbe Long Period Magnetotelluric Array Data

NASA Astrophysics Data System (ADS)

Wei, Wenbo; Zhang, Letian; Jin, Sheng; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

2017-04-01

The on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma has created the spectacular topography of the Tibetan plateau. However, many first order questions remain to be answered as to the mechanisms behind this young orogenic process. Under the auspices of the SinoProbe Project, a three dimensional (3-D) Magnetotelluric (MT) array have been deployed on the Tibetan Plateau from 2010 to 2013 to better understand this orogeny. By the end of 2013, 1099 MT stations have been completed, including 102 combined broadband MT (BBMT) and long period MT (LMT) stations. In this study, MT data of these 102 combined stations have been used to investigate the deep lithospheric electrical structure of the Tibetan Plateau. MT impedances within the period range of 10 - 50000 s were extracted to be used for 3-D inversions with the ModEM code using the standard NLCG algorithm. The resulting lithospheric electrical structure of the Tibetan Plateau shows a distinct pattern of strong variation not only vertically, but also horizontally. Conductors are found to be widespread in the middle to lower crust. But their geometries are quite complex, and not obviously consistent with the hypothesis of continuous eastward channel flow. Instead, most crustal conductors in central and southern Tibet display a pattern of N-S extension. In the depth range of the upper mantle, two more conductive regions can be identified in the southern Qiangtang Terrane and in the central Lhasa Terrane. Resistor associated with the underthrust Inidan plate can be traced beneath the Bangong-Nujiang suture in western Tibet, but only beneath the central Lhasa terrane in central Tibet. * This work was jointly supported by the grants from Project SinoProbe-01 and National Natural Science Foundation of China (41404060).

Different responses of ecosystem carbon exchange to warming in three types of alpine grassland on the central Qinghai-Tibetan Plateau.

PubMed

Ganjurjav, Hasbagan; Hu, Guozheng; Wan, Yunfan; Li, Yue; Danjiu, Luobu; Gao, Qingzhu

2018-02-01

Climate is a driver of terrestrial ecosystem carbon exchange, which is an important product of ecosystem function. The Qinghai-Tibetan Plateau has recently been subjected to a marked increase in temperature as a consequence of global warming. To explore the effects of warming on carbon exchange in grassland ecosystems, we conducted a whole-year warming experiment between 2012 and 2014 using open-top chambers placed in an alpine meadow, an alpine steppe, and a cultivated grassland on the central Qinghai-Tibetan Plateau. We measured the gross primary productivity, net ecosystem CO 2 exchange (NEE), ecosystem respiration, and soil respiration using a chamber-based method during the growing season. The results show that after 3 years of warming, there was significant stimulation of carbon assimilation and emission in the alpine meadow, but both these processes declined in the alpine steppe and the cultivated grassland. Under warming conditions, the soil water content was more important in stimulating ecosystem carbon exchange in the meadow and cultivated grassland than was soil temperature. In the steppe, the soil temperature was negatively correlated with ecosystem carbon exchange. We found that the ambient soil water content was significantly correlated with the magnitude of warming-induced change in NEE. Under high soil moisture condition, warming has a significant positive effect on NEE, while it has a negative effect under low soil moisture condition. Our results highlight that the NEE in steppe and cultivated grassland have negative responses to warming; after reclamation, the natural meadow would subject to loose more C in warmer condition. Therefore, under future warmer condition, the overextension of cultivated grassland should be avoided and scientific planning of cultivated grassland should be achieved.

A conceptual model of the controlling factors of soil organic carbon and nitrogen densities in a permafrost-affected region on the eastern Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wu, Xiaodong; Fang, Hongbing; Zhao, Yonghua; Smoak, Joseph M.; Li, Wangping; Shi, Wei; Sheng, Yu; Zhao, Lin; Ding, Yongjian

2017-07-01

Many investigations of the preservation of soil organic carbon (SOC) in permafrost regions have examined roles of geomorphology, pedogenesis, vegetation cover, and permafrost within particular regions. However, it is difficult to disentangle the effects of multiple factors on the SOC in permafrost regions due to the heterogeneity in environmental conditions. Based on data from 73 soil study sites in permafrost regions of the eastern Qinghai-Tibetan Plateau, we developed a simple conceptual model, which relates SOC to topography, vegetation, and pedogenesis. We summarized the dominant factors and their controls on SOC using 31 measured soil physiochemical variables. Soil texture explains approximately 60% of the variations in the SOC stocks for the upper 0-2 m soil. Soil particle size closely correlates to soil moisture, which is an important determinant of SOC. Soil salinity and cations are important factors as well and can explain about 10% of the variations in SOC. The SOC and total nitrogen (TN) stocks for the 1-2 m depths have larger uncertainties than those of upper 1 m soil layer. The vegetation, pH, and bulk density mainly affects SOC and TN stocks for the upper 1 m soil layers, while the active layer thickness and soil particle size have greater influence on SOC and TN stocks for the 1-2 m soils. Our results suggest that the soil particle size is the most important controller of SOC pools, and the stocks of SOC and TN are strongly effected by soil development processes in the permafrost regions of the eastern Qinghai-Tibetan Plateau.

Spatial Variability of Soil Water and Soil Organic Carbon Contents Under Different Degradation Degrees of Alpine Meadow Soil over the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zeng, C.; Zhang, F.

2014-12-01

Alpine meadow is one of widespread vegetation types of the Qinghai-Tibetan Plateau. However, alpine meadow ecosystem is undergoing degradation in recent years. The degradation of alpine meadow can changes soil physical and chemical properties as well as it's spatial variability. However, little research has been done that address the spatial patterns of soil properties under different degradation degrees of alpine meadow of the Qinghai-Tibetan Plateau although these changes were important to water and heat study and modelling of land surface. 296 soil surface (0-10 cm) samples were collected using grid sampling design from three different degraded alpine meadow regions (1 km2). Then soil water content (SWC) and organic carbon content (OCC) were measured. Classical statistical and geostatistical methods were employed to study the spatial heterogeneities of SWC and OCC under different degradation degrees (Non-degraded ND, moderately degraded MD, extremely degraded ED) of alpine meadow. Results show that both SWC and OCC of alpine meadow were normally distributed with the exception of SWC under ED. On average, both SWC and OCC of alpine meadow decreased in the order that ND > MD > ED. For nugget ratios, SWC and OCC of alpine meadow showed increasing spatial dependence tendency from ND to ED. For the range of spatial variation, both SWC and OCC of alpine meadow showed increasing tendency in distance with the increasing degree of degradation. In all, the degradation of alpine meadow has significant impact on spatial heterogeneities of SWC and OCC of alpine meadow. With increasing of alpine meadow degradation, soil water condition and nutrient condition become worse, and their distributions in spatial become unevenly.

Seasonal and Inter-Annual Variations in Carbon Dioxide Exchange over an Alpine Grassland in the Eastern Qinghai-Tibetan Plateau.

PubMed

Shang, Lunyu; Zhang, Yu; Lyu, Shihua; Wang, Shaoying

2016-01-01

This work analyzed carbon dioxide exchange and its controlling factors over an alpine grassland on the eastern Qinghai-Tibetan Plateau. The main results show that air temperature and photosynthetically active radiation are two dominant factors controlling daily gross primary production. Soil temperature and soil water content are the main factors controlling ecosystem respiration. Canopy photosynthetic activity is also responsible for the variation of daily ecosystem respiration other than environmental factors. No clear correlation between net ecosystem exchange and environmental factors was observed at daily scale. Temperature sensitive coefficient was observed to increase with larger soil water content. High values of temperature sensitive coefficient occurred during the periods when soil water content was high and grass was active. Annual integrated net ecosystem exchange, gross primary production and ecosystem respiration were -191, 1145 and 954 g C m-2 for 2010, and -250, 975 and 725 g C m-2 for 2011, respectively. Thus, this alpine grassland was a moderate carbon sink in both of the two years. Compared to alpine grasslands on the Qinghai-Tibetan Plateau, this alpine grassland demonstrated a much greater potential for carbon sequestration than others. Annual precipitation is a dominant factor controlling the variation of annual net ecosystem exchange over this grassland. The difference in gross primary production between the two years was not caused by the variation in annual precipitation. Instead, air temperature and the length of growing season had an important impact on annual gross primary production. Variation of annual ecosystem respiration was closely related to annual gross primary production and soil water content during the growing season.

Isolation, identification and fibrolytic characteristics of rumen fungi grown with indigenous methanogen from yaks (Bos grunniens) grazing on the Qinghai-Tibetan Plateau.

PubMed

Wei, Y-Q; Yang, H-J; Luan, Y; Long, R-J; Wu, Y-J; Wang, Z-Y

2016-03-01

To obtain co-cultures of anaerobic fungi and their indigenously associated methanogens from the rumen of yaks grazing on the Qinghai-Tibetan Plateau and investigate their morphology features and ability to degrade lignocellulose. Twenty fungus-methanogen co-cultures were obtained by Hungate roll-tube technique. The fungi were identified as Orpinomyces, Neocallimastix and Piromyces genera based on the morphological characteristics and internal transcribed spacer 1 sequences analysis. All methanogens were identified as Methanobrevibacter sp. by 16S rRNA gene sequencing. There were four types of co-cultures: Neocallimastix with Methanobrevibacter ruminantium, Orpinomyces with M. ruminantium, Orpinomyces with Methanobrevibacter millerae and Piromyces with M. ruminantium among 20 co-cultures. In vitro studies with wheat straw as substrate showed that the Neocallimastix with M. ruminantium co-cultures and Piromyces with M. ruminantium co-cultures exhibited higher xylanase, filter paper cellulase (FPase), ferulic acid esterase, acetyl esterase activities, in vitro dry matter digestibility, gas, CH4 , acetate production, ferulic acid and p-coumaric acid releases. The Neocallimastix frontalis Yak16 with M. ruminantium co-culture presented the strongest lignocellulose degradation ability among 20 co-cultures. Twenty fungus-methanogen co-cultures were obtained from the rumen of grazing yaks. The N. frontalis with M. ruminantium co-cultures were highly effective combination for developing a fermentative system that bioconverts lignocellulose to high activity fibre-degrading enzyme, CH4 and acetate. The N. frontalis with M. ruminantium co-cultures from yaks grazing on the Qinghai-Tibetan Plateau present great potential in lignocellulose biodegradation industry. © 2015 The Society for Applied Microbiology.

Seasonal and Inter-Annual Variations in Carbon Dioxide Exchange over an Alpine Grassland in the Eastern Qinghai-Tibetan Plateau

PubMed Central

Shang, Lunyu; Zhang, Yu; Lyu, Shihua; Wang, Shaoying

2016-01-01

This work analyzed carbon dioxide exchange and its controlling factors over an alpine grassland on the eastern Qinghai-Tibetan Plateau. The main results show that air temperature and photosynthetically active radiation are two dominant factors controlling daily gross primary production. Soil temperature and soil water content are the main factors controlling ecosystem respiration. Canopy photosynthetic activity is also responsible for the variation of daily ecosystem respiration other than environmental factors. No clear correlation between net ecosystem exchange and environmental factors was observed at daily scale. Temperature sensitive coefficient was observed to increase with larger soil water content. High values of temperature sensitive coefficient occurred during the periods when soil water content was high and grass was active. Annual integrated net ecosystem exchange, gross primary production and ecosystem respiration were -191, 1145 and 954 g C m-2 for 2010, and -250, 975 and 725 g C m-2 for 2011, respectively. Thus, this alpine grassland was a moderate carbon sink in both of the two years. Compared to alpine grasslands on the Qinghai-Tibetan Plateau, this alpine grassland demonstrated a much greater potential for carbon sequestration than others. Annual precipitation is a dominant factor controlling the variation of annual net ecosystem exchange over this grassland. The difference in gross primary production between the two years was not caused by the variation in annual precipitation. Instead, air temperature and the length of growing season had an important impact on annual gross primary production. Variation of annual ecosystem respiration was closely related to annual gross primary production and soil water content during the growing season. PMID:27861616

Experimental Warming Aggravates Degradation-Induced Topsoil Drought in Alpine Meadows of The Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Xue, X.

2017-12-01

Climatic warming is presumed to cause topsoil drought by increasing evapotranspiration and water infiltration, and by progressively inducing land degradation in alpine meadows of the Qinghai-Tibetan Plateau. However, how soil moisture and temperature patterns of degraded alpine meadows respond to climate warming remains unclear. A six-year continuous warming experiment was carried out in both degraded and undegraded alpine meadows in the source region of the Yangtze River. The goal was to identify the effects of climatic warming and land degradation on soil moisture (θ), soil surface temperature (Tsfc), and soil temperature (Ts). In the present study, land degradation significantly reduced θ by 4.5-6.1% at a depth of 0-100 cm (P < 0.001), and increased the annual mean Tsfc by 0.8°C. Warming with an infrared heater (radiation output of 150 W m-2) significantly increased the annual mean Tsfc by 2.5°C (P < 0.001) and significantly increased θ by 4.7% at a depth of 40-60 cm. Experimental warming in degraded land reversed the positive effects of the infrared heater and caused the yearly average θ to decrease significantly by 3.7-8.1% at a depth of 0-100 cm. Our research reveals that land degradation caused a significant water deficit near the soil surface. Experimental warming aggravated topsoil drought caused by land degradation, intensified the magnitude of degradation, and caused a positive feedback in the degraded alpine meadow ecosystem. Therefore, an immediate need exists to restore degraded alpine meadow grasslands in the Qinghai-Tibetan Plateau in anticipation of a warmer future.

Signals of pollution revealed by trace elements in recent snow from mountain glaciers at the Qinghai-Tibetan plateau.

PubMed

Li, Yuefang; Li, Zhen; Cozzi, Giulio; Turetta, Clara; Barbante, Carlo; Huang, Ju; Xiong, Longfei

2018-06-01

In order to extract pollution signal of trace elements (TEs) in glacier snow at the Qinghai-Tibetan plateau of China by human activities, concentrations of 18 TEs (Al, Ti, Fe, Rb, Sr, Ba, V, Cr, Mn, Li, Cu, Co, Mo, Cs, Sb, Pb, Tl, and U), 14 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), Y and Th in digested snow samples from five glaciers in April-May 2013 before monsoon season were measured. Results shown that higher TEs concentrations were found in glaciers at the northern plateau while lower concentrations in glaciers at the central and southern plateau. Discussion revealed that EF values calculated from elements with mass fraction <30% such as Ti and Al, etc in traditional acid leached samples, will overestimate at least 4.6 times the contribution of other sources than dust for TEs such as Sb, Sr, As, Cu and Pb etc. Analysis indicated that most TEs mainly originated from dust sources, whereas Pb, Cu, Mo and Sb showed occasionally significant contributions from polluted sources in three snow pits and the GRHK surface snow samples. The pollution probably originated from mining and smelting, road transport emissions on the plateau and some regions outside of the plateau. Dust provenance tracing results based on REEs indicated that Taklimakan Desert, Qaidam Basin, and Tibetan surface soil were the potential dust sources for the studied glaciers, while the Indian Thar Desert was an occasional dust sources for YZF,XDKMD and GRHK snow samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Functional Evolution of Leptin of Ochotona curzoniae in Adaptive Thermogenesis Driven by Cold Environmental Stress

PubMed Central

Yang, Jie; Bromage, Timothy G.; Zhao, Qian; Xu, Bao Hong; Gao, Wei Li; Tian, Hui Fang; Tang, Hui Jun; Liu, Dian Wu; Zhao, Xin Quan

2011-01-01

Background Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. Methodology/Principal Findings To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. Conclusions/Significance These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau. PMID:21698227

[Textual research for Tibetan medicine Qumazi].

PubMed

Luo, Wu-zheng; Li, Qi-en; Chen, Jing; Dor, Jerenchen; Tao, Si-yu; Shi Jin-bo; Xu, Ying-zhou; Yan, Xing-li

2015-05-01

Qumazi is a commonly used Tibetan medicine. With a long history, it can be found in the Four Medical Tantras written by gYu-thog rNying-ma Yon-tan mGon-po since the 8th century AD. Qumazi grows in mudflats and fields, including species growing in highlands, lowlands, mountains and farmlands. According to records in Crystal Beads Materia Medica, it features green sword-shaped leaves, thin stems with red veins, inserted panicles, white chicken-like flowers and copper needle row-like roots. However, there are many inconsistent morphological descriptions for Qumazi plants in many Chinese versions of Tibetan medicine books. In this article, after studying ancient and modern Tibetan medicine books, consulting experts and conducting surveys, the authors confirmed that Qumazi belongs to Rheum of Polygonaceae, including Rheum nobile Hook. f. et. Thoms, R. globulosum Gage, R. alexandrae Hook. f. et. Thoms, R. pumilum Maxim and R. delavayi Franch. In some regions, Qumazi is substituted by R. spiciforme Royle and R. przewalskyi Losinsk. After the Chinese version of Qinghai-Tibet Plateau Drug Illustrations was published in 1972, Qumazi has been miswritten as P. sibiricum Laxm in many Chinese versions of Tibetan medicine books, perhaps because P. sibiricum Laxm has many similar features with Qumazi as described in Crystal Beads Materia Medica and then is mistranslated from Tibetan to Chinese versions. According to records, Qumazi can reduce edema and is mainly applied to treat the minamata disease in clinic.

Comparative Transcriptomics of Strawberries (Fragaria spp.) Provides Insights into Evolutionary Patterns.

PubMed

Qiao, Qin; Xue, Li; Wang, Qia; Sun, Hang; Zhong, Yang; Huang, Jinling; Lei, Jiajun; Zhang, Ticao

2016-01-01

Multiple closely related species with genomic sequences provide an ideal system for studies on comparative and evolutionary genomics, as well as the mechanism of speciation. The whole genome sequences of six strawberry species ( Fragaria spp.) have been released, which provide one of the richest genomic resources of any plant genus. In this study, we first generated seven transcriptome sequences of Fragaria species de novo , with a total of 48,557-82,537 unigenes per species. Combined with 13 other species genomes in Rosales, we reconstructed a phylogenetic tree at the genomic level. The phylogenic tree shows that Fragaria closed grouped with Rubus and the Fragaria clade is divided into three subclades. East Asian species appeared in every subclade, suggesting that the genus originated in this area at ∼7.99 Mya. Four species found in mountains of Southwest China originated at ∼3.98 Mya, suggesting that rapid speciation occurred to adapt to changing environments following the uplift of the Qinghai-Tibet Plateau. Moreover, we identified 510 very significantly positively selected genes in the cultivated species F . × ananassa genome. This set of genes was enriched in functions related to specific agronomic traits, such as carbon metabolism and plant hormone signal transduction processes, which are directly related to fruit quality and flavor. These findings illustrate comprehensive evolutionary patterns in Fragaria and the genetic basis of fruit domestication of cultivated strawberry at the genomic/transcriptomic level.

Actinomyces vulturis sp. nov., isolated from Gyps himalayensis.

PubMed

Meng, Xiangli; Lu, Shan; Wang, Yiting; Lai, Xin-He; Wen, Yumeng; Jin, Dong; Yang, Jing; Bai, Xiangning; Zhang, Gui; Pu, Ji; Lan, Ruiting; Xu, Jianguo

2017-06-01

Two strains of Gram-stain-positive, facultatively anaerobic, non-spore-forming short rods (VUL7T and VUL8) were isolated from rectal swabs of Old World vultures, namely Gyps himalayensis, in Tibet-Qinghai Plateau, China. Optimal growth occurred at 37 °C, pH 6-7, with 1 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences classified the two strains to the genus Actinomyces, with highest 16S rRNA gene sequence similarity (95 %) to type strains of Actinomyces haliotis, Actinomyces radicidentis and Actinomyces urogenitalis. The major cellular fatty acids were C18 : 1ω9c and C16 : 0. MK-10(H4) was the major respiratory quinone. The genomic DNA G+C content of the isolate was 54.4 mol%. DNA-DNA hybridization values with the most closely related species ofthe genusActinomyces was 24.6 %. The two strains can be differentiated from the most closely related species such as A. haliotis, A. radicidentis, A. graevenitzii and A. urogenitalis by a list of carbohydrate fermentations and enzyme activities. On the basis of physiological, biochemical and phylogenetic analysis, strains VUL7T and VUL8 represent novel species of the genus Actinomyces, for which the name Actinomyces vulturis sp. nov. is proposed. The type strain is VUL7T (=CGMCC 4.7366T=DSM 103437T).

Climate-driven increase of natural wetland methane emissions offset by human-induced wetland reduction in China over the past three decades

USGS Publications Warehouse

Zhu, Qiuan; Peng, Changhui; Liu, Jinxun; Jiang, Hong; Fang, Xiuqin; Chen, Huai; Niu, Zhichun; Gong, Peng; Lin, Guanghui; Wang, Meng; Yang, Yanzheng; Chang, Jie; Ge, Ying; Xiang, Wenhua; Deng, Xiangwen; He, Jin-Sheng

2016-01-01

Both anthropogenic activities and climate change can affect the biogeochemical processes of natural wetland methanogenesis. Quantifying possible impacts of changing climate and wetland area on wetland methane (CH4) emissions in China is important for improving our knowledge on CH4 budgets locally and globally. However, their respective and combined effects are uncertain. We incorporated changes in wetland area derived from remote sensing into a dynamic CH4 model to quantify the human and climate change induced contributions to natural wetland CH4 emissions in China over the past three decades. Here we found that human-induced wetland loss contributed 34.3% to the CH4 emissions reduction (0.92 TgCH4), and climate change contributed 20.4% to the CH4 emissions increase (0.31 TgCH4), suggesting that decreasing CH4 emissions due to human-induced wetland reductions has offset the increasing climate-driven CH4 emissions. With climate change only, temperature was a dominant controlling factor for wetland CH4 emissions in the northeast (high latitude) and Qinghai-Tibet Plateau (high altitude) regions, whereas precipitation had a considerable influence in relative arid north China. The inevitable uncertainties caused by the asynchronous for different regions or periods due to inter-annual or seasonal variations among remote sensing images should be considered in the wetland CH4 emissions estimation.

Production and genetic analysis of resynthesized Brassica napus from a B. rapa landrace from the Qinghai-Tibet Plateau and B. alboglabra.

PubMed

Liu, H D; Zhao, Z G; Du, D Z; Deng, C R; Fu, G

2016-01-08

This study aimed to reveal the genetic and epigenetic variations involved in a resynthesized Brassica napus (AACC) generated from a hybridization between a B. rapa (AA) landrace and B. alboglabra (CC). Amplified fragment length polymorphism (AFLP), methylation-sensitive amplified polymorphism, and the cDNA-AFLP technique were performed to detect changes between different generations at the genome, methylation, and transcription levels. We obtained 30 lines of resynthesized B. napus with a mean 1000-seed weight of over 7.50 g. All of the lines were self-compatible, probably because both parents were self-compatible. At the genome level, the S0 generation had the lowest frequency of variations (0.18%) and the S3 generation had the highest (6.07%). The main variation pattern was the elimination of amplified restriction fragments on the CC genome from the S0 to the S4 generations. At the methylation level, we found three loci that exhibited altered methylation patterns on the parental A genome; the variance rate was 1.35%. At the transcription level, we detected 43.77% reverse mutations and 37.56% deletion mutations that mainly occurred on the A and C genomes, respectively, in the S3 generation. Our results highlight the genetic variations that occur during the diploidization of resynthesized B. napus.

Climate-driven increase of natural wetland methane emissions offset by human-induced wetland reduction in China over the past three decades

PubMed Central

Zhu, Qiuan; Peng, Changhui; Liu, Jinxun; Jiang, Hong; Fang, Xiuqin; Chen, Huai; Niu, Zhenguo; Gong, Peng; Lin, Guanghui; Wang, Meng; Wang, Han; Yang, Yanzheng; Chang, Jie; Ge, Ying; Xiang, Wenhua; Deng, Xiangwen; He, Jin-Sheng

2016-01-01

Both anthropogenic activities and climate change can affect the biogeochemical processes of natural wetland methanogenesis. Quantifying possible impacts of changing climate and wetland area on wetland methane (CH4) emissions in China is important for improving our knowledge on CH4 budgets locally and globally. However, their respective and combined effects are uncertain. We incorporated changes in wetland area derived from remote sensing into a dynamic CH4 model to quantify the human and climate change induced contributions to natural wetland CH4 emissions in China over the past three decades. Here we found that human-induced wetland loss contributed 34.3% to the CH4 emissions reduction (0.92 TgCH4), and climate change contributed 20.4% to the CH4 emissions increase (0.31 TgCH4), suggesting that decreasing CH4 emissions due to human-induced wetland reductions has offset the increasing climate-driven CH4 emissions. With climate change only, temperature was a dominant controlling factor for wetland CH4 emissions in the northeast (high latitude) and Qinghai-Tibet Plateau (high altitude) regions, whereas precipitation had a considerable influence in relative arid north China. The inevitable uncertainties caused by the asynchronous for different regions or periods due to inter-annual or seasonal variations among remote sensing images should be considered in the wetland CH4 emissions estimation. PMID:27892535

Seasonal variation of metabolism in lizard Phrynocephalus vlangalii at high altitude.

PubMed

Liang, Shiwei; Li, Weixin; Zhang, Yang; Tang, Xiaolong; He, Jianzheng; Bai, Yucheng; Li, Dongqin; Wang, Yan; Chen, Qiang

2017-01-01

Seasonal acclimatization is important for animals to live optimally in the varying environment. Phrynocephalus vlangalii, a species of lizard endemic in China, distributes on Qinghai-Tibet Plateau ranging from 2000 to 4600m above sea level. To dissect how this lizard mediate metabolism to adapt various season, the preferred body temperature (Tb), standard metabolic rate (SMR), mitochondrial respiration rates and activities of four metabolic enzymes in this species were tested in different seasons (spring, summer, and autumn). The results showed that the preferred Tb was the lowest in spring and the highest in summer. SMR, maximal mitochondrial respiration rates in liver and skeletal muscle were the highest in spring. Similarly, higher activities of lactate dehydrogenase (LDH), citrate synthase (CS) and cytochrome c oxidase (CCO) activities of liver and skeletal muscle were observed in spring. However, β-hydroxyacyl coenzyme A dehydrogenase (HOAD) activities of liver and skeletal muscle were higher in autumn. On the whole, seasonal variation of metabolism is the highest in spring and the lowest in summer. Seasonal variation of metabolism is the opposite of preferred body temperature, this may be one of the mechanisms to adapt to the environment in P. vlangalii. Our results suggested that P. vlangalii at high altitude has certain adaptive characteristics on metabolism in different seasons. Copyright © 2016 Elsevier Inc. All rights reserved.

Spatiotemporal Evolution of Calophaca (Fabaceae) Reveals Multiple Dispersals in Central Asian Mountains

PubMed Central

Zhang, Ming-Li; Wen, Zhi-Bin; Fritsch, Peter W.; Sanderson, Stewart C.

2015-01-01

Background The Central Asian flora plays a significant role in Eurasia and the Northern Hemisphere. Calophaca, a member of this flora, includes eight currently recognized species, and is centered in Central Asia, with some taxa extending into adjacent areas. A phylogenetic analysis of the genus utilizing nuclear ribosomal ITS and plastid trnS-trnG and rbcL sequences was carried out in order to confirm its taxonomic status and reconstruct its evolutionary history. Methodology/Principal Finding We employed BEAST Bayesian inference for dating, and S-DIVA and BBM for ancestral area reconstruction, to study its spatiotemporal evolution. Our results show that Calophacais monophyletic and nested within Caragana. The divergence time of Calophaca is estimated at ca. 8.0 Ma, most likely driven by global cooling and aridification, influenced by rapid uplift of the Qinghai Tibet Plateau margins. Conclusions/Significance According to ancestral area reconstructions, the genus most likely originated in the Pamir Mountains, a global biodiversity hotspot and hypothesized Tertiary refugium of many Central Asian plant lineages. Dispersals from this location are inferred to the western Tianshan Mountains, then northward to the Tarbagatai Range, eastward to East Asia, and westward to the Caucasus, Russia, and Europe. The spatiotemporal evolution of Calophaca provides a case contributing to an understanding of the flora and biodiversity of the Central Asian mountains and adjacent regions. PMID:25849146

Microbial community structure and diversity within hypersaline Keke Salt Lake environments.

PubMed

Han, Rui; Zhang, Xin; Liu, Jing; Long, Qifu; Chen, Laisheng; Liu, Deli; Zhu, Derui

2017-11-01

Keke Salt Lake is located in the Qaidamu Basin of China. It is a unique magnesium sulfate-subtype hypersaline lake that exhibits a halite domain ecosystem, yet its microbial diversity has remained unstudied. Here, the microbial community structure and diversity was investigated via high-throughput sequencing of the V3-V5 regions of 16S rRNA genes. A high diversity of operational taxonomic units was detected for Bacteria and Archaea (734 and 747, respectively), comprising 21 phyla, 43 classes, and 201 genera of Bacteria and 4 phyla, 4 classes, and 39 genera of Archaea. Salt-saturated samples were dominated by the bacterial genera Bacillus (51.52%-58.35% relative abundance), Lactococcus (9.52%-10.51%), and Oceanobacillus (8.82%-9.88%) within the Firmicutes phylum (74.81%-80.99%), contrasting with other hypersaline lakes. The dominant Archaea belonged to the Halobacteriaceae family, and in particular, the genera (with an abundance of >10% of communities) Halonotius, Halorubellus, Halapricum, Halorubrum, and Natronomonas. Additionally, we report the presence of Nanohaloarchaeota and Woesearchaeota in Qinghai-Tibet Plateau lakes, which has not been previously documented. Total salinity (especially Mg 2+ , Cl - , Na + , and K + ) mostly correlated with taxonomic distribution across samples. These results expand our understanding of microbial resource utilization within hypersaline lakes and the potential adaptations of dominant microorganisms that allow them to inhabit such environments.

The paradox of the individual household responsibility system in the grasslands of the Tibetan Plateau, China

Treesearch

Camille Richard; Yan Zhaoli; Du Guozhen

2006-01-01

Grasslands of the Tibetan plateau are commonly believed to be degrading as a result of unsustainable grazing practices. In response, the Grassland Law attempts to allocate grasslands based on the Individual Household Responsibility System model that has worked in the agricultural areas of China. However, the actual tenure scenario in the rangelands of Tibet is not as...

Evolutionary origin and demographic history of an ancient conifer (Juniperus microsperma) in the Qinghai-Tibetan Plateau

PubMed Central

Shang, Hui-Ying; Li, Zhong-Hu; Dong, Miao; Adams, Robert P.; Miehe, Georg; Opgenoorth, Lars; Mao, Kang-Shan

2015-01-01

All Qinghai-Tibetan Plateau (QTP) endemic species are assumed to have originated recently, although very rare species most likely diverged early. These ancient species provide an excellent model to examine the origin and evolution of QTP endemic plants in response to the QTP uplifts and the climate changes that followed in this high altitude region. In this study, we examined these hypotheses by employing sequence variation from multiple nuclear and chloroplast DNA of 239 individuals of Juniperus microsperma and its five congeners. Both phylogenetic and population genetic analyses revealed that J. microsperma diverged from its sister clade comprising two species with long isolation around the Early Miocene, which corresponds to early QTP uplift. Demographic modeling and coalescent tests suggest that J. microsperma experienced an obvious bottleneck event during the Quaternary when the global climate greatly oscillated. The results presented here support the hypotheses that the QTP uplifts and Quaternary climate changes played important roles in shaping the evolutionary history of this rare juniper. PMID:25977142

Effects of permafrost degradation on vegetation in the Source Area of the Yellow River NE Qinghai Tibetan Plateau

NASA Astrophysics Data System (ADS)

Xiaoying, Jin; Huijun, Jin

2017-04-01

Permafrost degradation caused by climate warming has markedly changed ecological environment in the Source Area of the Yellow River, in the northeast of the Qinghai Tibetan Plateau. However, related research about ecological impact of permafrost degradation is limited in this area. More attentions should be paid to the impact of permafrost degradation on alpine grassland. In this study vegetation characteristics (plant species composition, vegetation cover and biomass, etc.) at different permafrost degradation stages (as represented by the continuous and discontinuous permafrost zone, transitional zone, and seasonally frozen ground zone) is investigated. The results showed that (1) there are total 64 species in continuous and discontinuous permafrost zone, transitional zone, and seasonally frozen ground zone, and seasonally frozen ground zone has more species than transitional zone and permafrost zone, (2) sedge is the dominant species in three zones. But Shrub only presented in the seasonally frozen ground zone. These results suggest that permafrost degradation affect the species number and species composition of alpine grassland.

Tibet

Atmospheric Science Data Center

2013-04-16

...     View Larger Image The Tibetan Plateau and a portion of the Himalayan Mountain chain ... to many of the world's highest peaks. Himalaya is a Sanskrit word meaning "the Abode of Snow". Mt. Everest (8848 meters) and Mt. Makalu ...

Detection and attribution of vegetation greening trend in China over the last 30 years

DOE PAGES

Piao, Shilong; Yin, Guodong; Tan, Jianguang; ...

2014-11-04

The reliable detection and attribution of changes in vegetation growth is a prerequisite for the development of strategies for the sustainable management of ecosystems. This is an extraordinary challenge. To our knowledge, this study is the first to comprehensively detect and attribute a greening trend in China over the last three decades. Here, we use three different satellite-derived Leaf Area Index (LAI) datasets for detection as well as five different process-based ecosystem models for attribution. Rising atmospheric CO 2 concentration and nitrogen deposition are identified as the most likely causes of the greening trend in China, explaining 85% and 41%more » of the average growing-season LAI trend (LAI GS) estimated by satellite datasets (average trend of 0.0070yr -1, ranging from 0.0035yr -1 to 0.0127yr -1), respectively. The contribution of nitrogen deposition is more clearly seen in southern China than in the north of the country. Models disagree about the contribution of climate change alone to the trend in LAI GS at the country scale (one model shows a significant increasing trend, whereas two others show significant decreasing trends). However, the models generally agree on the negative impacts of climate change in north China and Inner Mongolia and the positive impact in the Qinghai-Xizang plateau. Provincial forest area change tends to be significantly correlated with the trend of LAI GS (P<0.05), and marginally significantly (P=0.07) correlated with the residual of LAI(GS) trend, calculated as the trend observed by satellite minus that estimated by models through considering the effects of climate change, rising CO 2 concentration and nitrogen deposition, across different provinces. In conclusion, this result highlights the important role of China's afforestation program in explaining the spatial patterns of trend in vegetation growth.« less

Detection and attribution of vegetation greening trend in China over the last 30 years

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piao, Shilong; Yin, Guodong; Tan, Jianguang

The reliable detection and attribution of changes in vegetation growth is a prerequisite for the development of strategies for the sustainable management of ecosystems. This is an extraordinary challenge. To our knowledge, this study is the first to comprehensively detect and attribute a greening trend in China over the last three decades. Here, we use three different satellite-derived Leaf Area Index (LAI) datasets for detection as well as five different process-based ecosystem models for attribution. Rising atmospheric CO 2 concentration and nitrogen deposition are identified as the most likely causes of the greening trend in China, explaining 85% and 41%more » of the average growing-season LAI trend (LAI GS) estimated by satellite datasets (average trend of 0.0070yr -1, ranging from 0.0035yr -1 to 0.0127yr -1), respectively. The contribution of nitrogen deposition is more clearly seen in southern China than in the north of the country. Models disagree about the contribution of climate change alone to the trend in LAI GS at the country scale (one model shows a significant increasing trend, whereas two others show significant decreasing trends). However, the models generally agree on the negative impacts of climate change in north China and Inner Mongolia and the positive impact in the Qinghai-Xizang plateau. Provincial forest area change tends to be significantly correlated with the trend of LAI GS (P<0.05), and marginally significantly (P=0.07) correlated with the residual of LAI(GS) trend, calculated as the trend observed by satellite minus that estimated by models through considering the effects of climate change, rising CO 2 concentration and nitrogen deposition, across different provinces. In conclusion, this result highlights the important role of China's afforestation program in explaining the spatial patterns of trend in vegetation growth.« less

Upper Mantle Seismic Structure for NE Tibet From Multiscale Tomography Method

NASA Astrophysics Data System (ADS)

Guo, B.; Liu, Q.; Chen, J.

2013-12-01

In the real seismic experiments, the spatial sampling of rays inside the studied volume is basically nonuniform because of the unequispaced distribution of the seismic stations as well as the earthquake events. The conventional seismic tomography schemes adopt fixed size of cells or grid spacing while the actual resolution varies. As a result, either the phantom velocity anomalies may be aroused in regions that are poorly illuminated by the seismic rays, or the best detailed velocity model is unable to be extracted from those with fine ray coverage. We present an adaptive wavelet parameterization solution for three-dimensional traveltime seismic tomography problem and apply it to the study of the tectonics in the Northeast Tibet region. Different from the traditional parameterization schemes, we discretize the velocity model in terms of the Haar wavelets and the parameters are adjusted adaptively based on both the density and the azimuthal coverage of rays. Therefore, the fine grids are used in regions with the good data coverage, whereas the poorly resolved areas are represented by the coarse grids. Using the traveltime data recorded by the portable seismic array and the regional seismic network in the northeastern Tibet area, we investigate the P wave velocity structure of the crust and upper mantle. Our results show that the structure of the crust and upper mantle in the northeastern Tibet region manifests a strong laterally inhomogeneity, which appears not only in the adjacent areas between the different blocks, but also within each block. The velocity of the crust and upper mantle is highly different between the northeastern Tibet and the Ordos plateau. Of these two regions, the former possesses a low-velocity feature while the latter is referred to a high-velocity pattern. Between the northeastern Tibet and the Ordos plateau, there is a transition zone of about 200km wide, which is associated with an extremely complex velocity structure in crust and upper mantle.

Upper- and mid-crustal radial anisotropy beneath the central Himalaya and southern Tibet from seismic ambient noise tomography

NASA Astrophysics Data System (ADS)

Guo, Zhi; Gao, Xing; Wang, Wei; Yao, Zhenxing

2012-05-01

Through analysis of the Rayleigh wave and Love wave empirical Green's functions recovered from cross-correlation of seismic ambient noise, we image the radial anisotropy and shear wave velocity structure beneath southern Tibet and the central Himalaya. Dense ray path coverage from 22 broadband seismic stations deployed by the Himalayan Nepal Tibet Seismic Experiment project provides the unprecedented opportunity to resolve the spatial distribution of the radial anisotropy within the crust of the central Himalaya and southern Tibet. In the shallow subsurface, the obtained results indicate significant radial anisotropy with negative magnitude (VSV > VSH) mainly associated with the Indus Yarlung Suture and central Himalaya, possibly related to the fossil microcracks or metamorphic foliations formed during the uplifting of the Tibetan Plateau. With increasing depth, the magnitude of radial anisotropy varies from predominantly negative to predominantly positive, and a mid-crustal layer with prominent positive radial anisotropy (VSV < VSH) has been detected. The top of the mid-crustal anisotropic layer correlates nicely with the starting depth of the mid-crustal lower velocity layers detected in our previous study. The spatial correlation of the positive radial anisotropy layers and mid-crustal lower velocity layers might suggest lateral crustal channel flow induced alignment of mineral grains, most likely micas or amphiboles, within the mid-crust of the central Himalaya and southern Tibet. This observation provides independent seismic evidence to support the thermo-mechanical model, which involves the southward extrusion of a low viscosity mid-crustal channel driven by the denudation effect focused at the southern flank of the Tibetan Plateau to explain the tectonic evolution of the Tibetan-Himalayan orogen.

Linking Tengchong Terrane in SW Yunnan with Lhasa Terrane in southern Tibet through magmatic correlation

NASA Astrophysics Data System (ADS)

Xie, Jincheng; Zhu, Dicheng; Dong, Guochen; Zhao, Zhidan; Wang, Qing

2016-04-01

New zircon U-Pb data, along with the data reported in the literature, reveal five phases of magmatic activity in the Tengchong Terrane since the Early Paleozoic with spatial and temporal variations summarized as: Cambrian-Ordovician (500-460 Ma) to the eastern, minor Triassic (245-206 Ma) in the eastern and western, abundant Early Cretaceous (131-114 Ma) in the eastern, extensive Late Cretaceous (77-65 Ma) in the central, and Paleocene-Eocene (65-49 Ma) in the central and western Tengchong Terrane, in which the Cretaceous-Eocene magmatism was migrated from east to west (Xu et al., 2012). The increased zircon eHf(t) of the Early Cretaceous granitoids from -12.3 to -1.4 at ca. 131-122 Ma to -4.6 to +7.1 at ca. 122-114 Ma identified for the first time in this study and the magmatic flare-up at ca. 53 Ma in the central and western Tengchong Terrane (Wang et al., 2014, Ma et al., 2015) indicate the increased contributions from mantle- or juvenile crust-derived components. The spatial and temporal variations and changing magmatic compositions with time in the Tengchong Terrane closely resemble the Lhasa Terrane in southern Tibet. Such similarities, together with the data of stratigraphy and paleobiogeography (Zhang et al., 2013), enable us to propose that the Tengchong Terrane in SW Yunnan is most likely linked with the Lhasa Terrane in southern Tibet, both of which experience similar tectonomagmatic histories since the Early Paleozoic. References Ma, L.Y., Wang, Y.J., Fan, W.M., Geng, H.Y., Cai, Y.F., Zhong, H., Liu, H.C., Xing, X.W., 2014. Petrogenesis of the early Eocene I-type granites in west Yingjiang (SW Yunnan) and its implication for the eastern extension of the Gangdese batholiths. Gondwana Research 25, 401-419. Wang, Y.J., Zhang, L.M., Cawood, P.A., Ma, L.Y., Fan, W.M., Zhang, A.M., Zhang, Y.Z., Bi, X.W., 2014. Eocene supra-subduction zone mafic magmatism in the Sibumasu Block of SW Yunnan: Implications for Neotethyan subduction and India-Asia collision. Lithos 206-207, 384-399. Xu, Y.G., Yang, Q.J., Lan, J.B., Luo, Z.Y., Huang, X.L., Shi, Y.R., Xie, L.W., 2012. Temporal-spatial distribution and tectonic implications of the batholiths in the Gaoligong-Tengliang-Yingjiang area, western Yunnan: Constraints from zircon U-Pb ages and Hf isotopes. Journal of Asian Earth Sciences 53, 151-175. Zhang, Y.C., Shi, G.R., Shen, S.Z., 2013. A review of Permian stratigraphy, paleobiogeography and palaeogeography of the Qinghai-Tibet Plateau. Gondwana Research 24, 55-76.

Prehistoric human settling on the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Chen, F.; Zhang, D.; Dong, G.; Xia, H.

2017-12-01

When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By redating the age of hand- and footprints in Chusang site in Tibet, Meyer et al. (2017) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene (before 7.4 ka) without the help of agriculture. Except for the possible problem of dating, however, the limited hand- and footprints could only indicate the presence of prehistoric hunter-gatherers on the remote central Tibetan Plateau in the early Holocene, unable to support the permanent inhabitation assertion (Zhang et al., 2017). To better understand how human spread to, settle on and adapt to the Tibetan Plateau, we are closely working together with anthropologists, archaeologists and geneticists to do system Paleolithic surveys, full excavations, and genetic analysis of ancient and modern human, animals and plants. Our preliminary study show that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) with different adaptation strategies, including microlithic technology, millet and barley farming, and sheep herding and so on (Zhang et al., 2016). In addition, our new finds in Tibet indicate that there are probably more migration routes from southeast and southwest Tibetan Plateau in the late Pleistocene or early Holocene, other than the main routes of upper Yellow River valley in NETP. To better understand and answer those arguments, detailed Paleolithic surveys and studies are especially needed in the future.

Tibetan Plateau photographed during MA-9 22 orbit

NASA Image and Video Library

1963-05-16

S63-06440 (15-16 May 1963) --- View of the Tibetan Plateau in north-central Tibet, as photographed from the Mercury-Atlas 9 (MA-9) capsule by astronaut L. Gordon Cooper Jr., during his 22-orbit MA-9 spaceflight. The center of the photograph is near 91 degrees east longitude and 34 degrees 30 minutes north latitude. This view includes lakes and snow-covered highlands. Photo credit: NASA

Lithosphere structure of the west Qinling orogenic belt revealed by deep seismic reflection profile

NASA Astrophysics Data System (ADS)

Wang, H.

2009-12-01

The west Qinling orogen located in the northeastern margin of the Qinghai-Tibet plateau, is transformation zone between the N-S-trending and E-W-trending tectonics in the Chinese continent. Further study of the fine crust structure of the west Qinling orogen and its relationships with surrounding basins have very important significance for understanding tectonic response of the northeastern margin of the plateau about collision convergence of the Indian block and Asian block and learning formation and evolution of the plateau. In 2009, we reprocessed the data of the Tangke-Hezuo deep seismic reflection profiles collected in 2004 across the west Qinling orogen and the northern Songpan block. The new results show the lithosphere fine structure of the west Qinling orogen. Reflection features indicate that an interface at 6.0-7.0s (TWT) divided the crust into the upper and lower crust, whose structural style and deformation are totally different. Integrating geological data, we deduce that the interface at 6.0-7.0s (depth with 18-21 km) was the basement detachment, which made deformation decoupled of the upper and lower crust. The multi-layered reflections in the upper crust reveal the sedimentary covers of the west Qinling orogen, disclose the thickness of the various structure layer and deformation degree, and provide a basis for the prospective evaluation of a multi-metallic mineral and energy exploration. The north dipping strong reflection characteristics of the lower crust in the west Qinling orogen constituted imbricate structure, such imbricate structural features provide seismology evidence for researching the west Qinling thrusting toward the northern Songpan block, and have great significance for studying formation and evolution of the Songpan-Garze structure. Moho reflections are observed around 17.0-17.2s, characterized by nearly horizontal reflections, which implies the west Qinling orogen underwent an intense extension post orogeny caused the lithosphere extensional thinning formed a nearly level Moho reflections. The study was financed by National Natural Science Foundation of china (No. 40830316 and 40604010),the Basic outlay of scientific research work from Ministry of Science and Technology of the People’s Republic of China and SINOPPROBE-02.

The shallow sedimentary and structural deformation in the southern Longmen Shan: constraints on the seismotectonics of the 2013 Lushan Mw6.7 Earthquake

NASA Astrophysics Data System (ADS)

Lu, R.; Xu, X.; He, D.; Suppe, J.

2017-12-01

On April 20, 2013, an unexpected Mw 6.7 earthquake occurred in Lushan County at the southern Longmen Shan, the eastern margin of the Tibetan Plateau. After this Lushan earthquake, whether the seismogenic fault is a high-angle or low-angle fault? The structural characteristics, attribution, and the seismotectonic model of this earthquake have many debates and problems. In this study, a high-resolution seismic reflection profile was combined with near-surface geological data, earthquake relocation and geodetic measurements, and a recent deep artificial seismic reflection profile to identify the active fault and seismotectonics of this earthquake. Three-dimensional imaging of the aftershocks was used to identify two planar faults that together form a y-shape (f1 and f2). Seismic interpretations suggest that the seismogenic fault f1 is a typical basement blind fault that did not penetrate into the overlying Mesozoic and Cenozoic units, and it is not a Shuangshi-Dachuan fault (F4) or the frontal Dayi buried fault (F6). Geodetic measurements suggest that the coseismic deformation is consistent with the geometry and kinematics of shear fault-bend folding (FBF). The history of tectonic evolution since the Paleozoic in Longmen Shan area also referred. There are three major detachments control the structural deformation of the upper crust in the Longmen Shan and Western Sichuan Basin, resulting in multiple superimposed deformation events. Deep seismic data indicate the syndepositional nature of fault f1 a preexisting normal fault older than the Triassic, which underwent positive inversion tectonics during the Late Cenozoic. A thrust fault f3 converges with f1 at a depth of approximately12 km with an accumulated slip 3.6 km. This 2013 Lushan earthquake triggered by blind faults is a hidden earthquake. Since the Late Cenozoic, with the strong and on-going compression of the Qinghai-Tibet Plateau to the Sichuan Basin, the early-period normal faults were activated after inversion and triggered Lushan earthquakes. Blind and reactivated faults increase the potential risk and uncertainty related to earthquakes in the eastern margin of the Tibetan Plateau.

Kinematic development of the Tibetan Plateau's northern margin: A traverse across the Qilian Shan-Nan Shan thrust belt

NASA Astrophysics Data System (ADS)

Zuza, A. V.; Levy, D. A.; Wang, Z.; Xiong, X.; Chen, X.

2017-12-01

The active Cenozoic Qilian Shan-Nan Shan thrust belt defines the northern margin of the Tibetan Plateau. The kinematic development of this thrust belt has implications models of plateau growth and Himalayan-Tibetan orogen strain accommodation. We present new field observations and analytical data from a traverse across the 350-km-wide doubly vergent Qilian Shan, which is bound by the south-dipping North Qilian thrust system in the north and the north-dipping range-bounding Qinghai Nanshan-Dulan Shan thrust system in the south. These faults, and several other major thrusts within the thrust-belt interior, disrupt relatively thick Oligocene-Miocene basin deposits. Of note, many of the thrust faults across the width of the Qilian Shan have Quaternary fault scarps, indicating that active deformation is distributed and not only concentrated along the northern frontal faults. By integrating our detailed structural traverse with new geophysical observations and thermochronology data across the northern plateau margin, we construct a kinematic model for the development of the Tibetan Plateau's northern margin. Deformation initiated in the Eocene-Oligocene along the north-dipping Qinghai Nanshan-Dulan Shan and south-dipping Tuolai Nan Shan thrusts, the latter of which then defined the northern boundary of the Tibetan Plateau. This early deformation was focused along preexisting early Paleozoic structures. A 200-km-wide basin formed between these ranges, and from the Miocene to present, new thrust- and strike-slip-fault-bounded ranges developed, including the north-directed North Qilian and the south-directed Tuolai Nan thrusts. Thus, our observations do not support northward propagating thrust-belt expansion. Instead, we envision that the initial thrust-belt development generated a wide Oligocene-Miocene north-plateau basin that was subsequently disintegrated by later Miocene to present thrusting and strike-slip faulting. Ultimately, the Qilian Shan-Nan Shan thrust belt differs from a typical orogenic thrust wedge, and active deformation is distributed across the range.

Effects of grazing and precipitation on herbage biomass, herbage nutritive value, and yak performance in an alpine meadow on the Qinghai-Tibetan Plateau.

PubMed

Miao, Fuhong; Guo, Zhenggang; Xue, Ran; Wang, Xianzhi; Shen, Yuying

2015-01-01

The Qinghai-Tibetan Plateau is a very large land unit and an important terrestrial ecosystem within the Eurasian continent. Because of the harsh climate associated with the high altitude, alpine meadows on the plateau are susceptible to degradation from overgrazing. For this region, and for other alpine meadow pastures internationally, there is a need to define the sustainable stocking rate, to develop sound policy pertaining to future land use. Here we report biomass and liveweight gain per animal and per ha for pastures grazed by yaks at high, medium, or low stocking rates over 4 growing seasons from 2010 to 2013. Measures of herbage nutritive value are reported. The influence of inter-year variation in precipitation on standing herbage biomass was also evaluated. Higher precipitation increased standing herbage biomass and herbage nutritive value, indicating that vegetation suffered summer water deficit even in this environment. The sustainable stocking rate in this environment was determined to be approximately 1 yak ha-1 (grown from 80 kg to 120 kg liveweight in 90 d). At this stocking rate, yak weight gain per ha was 88% of that achieved at higher stocking rates typically used by farmers, but with little or no evidence of land degradation.

Mountain building at northeastern boundary of Tibetan Plateau and craton reworking at Ordos block from joint inversion of ambient noise tomography and receiver functions

NASA Astrophysics Data System (ADS)

Guo, Zhen; Chen, Yongshun John

2017-04-01

We have obtained a high resolution 3-D crustal and uppermost mantle velocity model of the Ordos block and its surrounding areas by joint inversion of ambient noise tomography and receiver functions using seismic recordings from 320 stations. The resulting model shows wide-spread low velocity zone (Vs ≤ 3.4 km/s) in the mid-to-lower crust beneath northeastern Tibet Plateau, which may favor crustal ductile flow within the plateau. However, our model argues against the eastward crustal ductile flow beneath the Qinling belt from the Tibetan Plateau. We find high velocities in the middle part of Qinling belt which separate the low velocities in the mid-to-lower crust of the eastern Qinling belt from the low velocity zone in eastern Tibetan Plateau. More importantly, we observe significant low velocities and thickened lower crust at the Liupanshan thrust belt as the evidence for strong crustal shortening at this boundary between the northeastern Tibetan Plateau and Ordos block. The most important finding of our model is the upper mantle low velocity anomalies surrounding the Ordos block, particularly the one beneath the Trans North China Craton (TNCO) that is penetrating into the southern margin of the Ordos block for ∼100 km horizontally in the depth range of ∼70 km and at least 100 km. We propose an on-going lithospheric mantle reworking at the southernmost boundary of the Ordos block due to complicated mantle flow surrounding the Ordos block, that is, the eastward asthenospheric flow from the Tibet Plateau proposed by recent SKS study and mantle upwelling beneath the TNCO from mantle transition zone induced by the stagnant slabs of the subducted Pacific plate.

Proceedings of the 25th Himalaya-Karakoram-Tibet Workshop

USGS Publications Warehouse

Leech, Mary L.; Klemperer, Simon L.; Mooney, Walter D.

2010-01-01

For a quarter of a century the Himalayan-Karakoram-Tibet (HKT) Workshop has provided scientists studying the India-Asia collision system a wonderful opportunity for workshop-style discussion with colleagues working in this region. In 2010, HKT returns to North America for the first time since 1996. The 25th international workshop is held from June 7 to10 at San Francisco State University, California. The international community was invited to contribute scientific papers to the workshop, on all aspects of geoscience research in the geographic area of the Tibetan Plateau and its bounding ranges and basins, from basic mapping to geochemical and isotopic analyses to large-scale geophysical imaging experiments. In recognition of the involvement of U.S. Geological Survey (USGS) scientists in a wide range of these activities, the USGS agreed to publish the extended abstracts of the numerous components of HKT-25 as an online Open-File Report, thereby ensuring the wide availability and distribution of these abstracts, particularly in the HKT countries from which many active workers are precluded by cost from attending international meetings. In addition to the workshop characterized by contributed presentations, participants were invited to attend a pre-meeting field trip from the Coast Ranges to the Sierra Nevada, to allow the international group to consider how the tectonic elements of the Pacific margin compare to those of the Himalayan belt. Following the workshop, the National Science Foundation (NSF) sponsored a workshop on the 'Future directions for NSF-sponsored geoscience research in the Himalaya/Tibet' intended to provide NSF Program Directors with a clear statement and vision of community goals for the future, including the scientific progress we can expect if NSF continues its support of projects in this geographic region, and to identify which key geoscience problems and processes are best addressed in the Himalaya and Tibet, what key datasets are needed, and how NSF can best support the evolving need for interdisciplinary investigations. This workshop also has clear societal relevance. Recent earthquakes have brought international attention to active tectonics and earthquake hazards in the HKT region. Prominent examples include the Mw 7.8 Kokoxili (Qinghai, China) earthquake of 2001, the Mw 7.6 Kashmir (Pakistan) earthquake of 2005, the Mw 7.9 Wenchuan (Sichuan, China) earthquake of 2008, and this year the Mw 6.9 Yushu (Qinghai, China) earthquake. Geological and geophysical field work conducted both before these earthquakes, as well as in response to them, has helped to define the active faults and regional tectonics in the HKT region. The research presented at this workshop provides the framework necessary for improved seismic hazard assessments in this region. The organizers gratefully acknowledge the support of NSF's Continental Dynamics Program and its Office of International Science and Engineering, through award EAR-0965796. We thank San Francisco State University's Sheldon Axler, Dean of the College of Science and Engineering, and Toby Garfield, Director of the Romberg Tiburon Center, for use of their conference facilities; and the Department of Geosciences, particularly Deb Shulman and Miriam Knof, for administrative support. The California Academy of Sciences generously hosted a reception for visiting delegates, and Brad Ritts (Chevron Exploration Technology Company), Todd Greene (California State University, Chico) and John Shervais (Utah State University) together co-led the pre-conference field trip. Technical editing of this volume was led by Roxanne Renedo (U.S. Geological Survey) with assistance from Margaret Milia (Stanford University). We are grateful to the U.S. Geological Survey (USGS) Earthquake Hazards Program and the USGS Menlo Park (California) Publishing Service Center for making this online report possible.

Pliocene-Quaternary crustal melting in central and northern Tibet and insights into crustal flow

PubMed Central

Wang, Qiang; Hawkesworth, Chris J.; Wyman, Derek; Chung, Sun-Lin; Wu, Fu-Yuan; Li, Xian-Hua; Li, Zheng-Xiang; Gou, Guo-Ning; Zhang, Xiu-Zheng; Tang, Gong-Jian; Dan, Wei; Ma, Lin; Dong, Yan-Hui

2016-01-01

There is considerable controversy over the nature of geophysically recognized low-velocity–high-conductivity zones (LV–HCZs) within the Tibetan crust, and their role in models for the development of the Tibetan Plateau. Here we report petrological and geochemical data on magmas erupted 4.7–0.3 Myr ago in central and northern Tibet, demonstrating that they were generated by partial melting of crustal rocks at temperatures of 700–1,050 °C and pressures of 0.5–1.5 GPa. Thus Pliocene-Quaternary melting of crustal rocks occurred at depths of 15–50 km in areas where the LV–HCZs have been recognized. This provides new petrological evidence that the LV–HCZs are sources of partial melt. It is inferred that crustal melting played a key role in triggering crustal weakening and outward crustal flow in the expansion of the Tibetan Plateau. PMID:27307135

Flavor evaluation of yak butter in Tsinghai-Tibet Plateau and isolation of microorganisms contributing flavor.

PubMed

Hu, SongQing; Wei, HaiLiu; Guo, ShaSha; Li, Lin; Hou, Yi

2011-02-01

Yak butter in Tsinghai-Tibet Plateau possesses the characters of high energy, abundant alimentation and a special flavor with certain medical and health care functions. In this paper the organoleptic flavor of yak butter was estimated, and 28 kinds of substance with different flavors were identified with the technique of coupling gas chromatography to mass spectroscopy (GC-MS). The results showed that there are many microorganisms in yak butter with natural inoculation, which contribute to the formation of its special flavors. It was found that three of these 15 microorganisms, identified as Saccharomycetaceae, Penicillium and Asperillus separately, contributed the most to flavors. The microorganisms are expected to be applied in the food industry, especially to produce dairy food with the unique flavor of yak butter. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Animal Science.

Topographic heterogeneity and temperature amplitude explain species richness patterns of birds in the Qinghai-Tibetan Plateau.

PubMed

Zhang, Chunlan; Quan, Qing; Wu, Yongjie; Chen, Youhua; He, Peng; Qu, Yanhua; Lei, Fumin

2017-04-01

Large-scale patterns of species richness have gained much attention in recent years; however, the factors that drive high species richness are still controversial in local regions, especially in highly diversified montane regions. The Qinghai-Tibetan Plateau (QTP) and the surrounding mountains are biodiversity hot spots due to a high number of endemic montane species. Here, we explored the factors underlying this high level of diversity by studying the relationship between species richness and environmental variables. The richness patterns of 758 resident bird species were summarized at the scale of 1°×1° grid cell at different taxonomic levels (order, family, genus, and species) and in different taxonomic groups (Passeriformes, Galliformes, Falconiformes, and Columbiformes). These richness patterns were subsequently analyzed against habitat heterogeneity (topographical heterogeneity and land cover), temperature amplitude (annual temperature, annual precipitation, precipitation seasonality, and temperature seasonality) and a vegetation index (net primary productivity). Our results showed that the highest richness was found in the southeastern part of the QTP, the eastern Himalayas. The lowest richness was observed in the central plateau of the QTP. Topographical heterogeneity and temperature amplitude are the primary factors that explain overall patterns of species richness in the QTP, although the specific effect of each environmental variable varies between the different taxonomic groups depending on their own evolutionary histories and ecological requirements. High species richness in the southeastern QTP is mostly due to highly diversified habitat types and temperature zones along elevation gradients, whereas the low species richness in the central plateau of the QTP may be due to environmental and energetic constraints, as the central plateau is harsh environment.

Geodynamical Evolution of the En echelon Basins in the Hexi Corridor: Implications From 3-D Numerical Modeling

NASA Astrophysics Data System (ADS)

Li, W.; Shi, Y.; Zhang, H.; Cheng, H.

2017-12-01

The Hexi Corridor, located between the Alax block and the Caledon fold belt in the North Qilian Mountains, is the forefront area of northward thrust of the Tibet Plateau. Most notably, this active tectonic region consists of a series of faults and western-northwest trending Cenozoic basins. Therefore, it's a pivotal part in terms of recording tectonic pattern of the Tibet Plateau and also demonstrating the northward growth of Tibetan Plateau. In order to explain the mechanism of formation and evolution of the paired basins in the Hexi Corridor and based on the visco-elasticity-plasticity constitutive relation, we construct a 3-D finite element numerical model, including the Altun Tagh fault zone, the northern Qilian Shan-Hexi corridor faults system and the Haiyuan fault zone in northeast of the Tibet Plateau.The boundary conditions are constrained by GPS observations and fault slip rate provided by field geology, with steady rate of deformation of north-south compression and lateral shear along the approximately east-west strike fault zones.In our numerical model, different blocks are given different mechanical features and major fault zones are assumed mechanical weak zones. The long-term (5Ma) accumulation of lithospheric stress, displacement and fault dislocation of the Hexi Corridor and its adjacent regions are calculated in different models for comparison. Meanwhile, we analyze analyzed how the crustal heterogeneity affecting the tectonic deformations in this region. Comparisons between the numerical results and the geological observations indicate that under compression-shear boundary conditions, heterogeneous blocks of various scales may lead to the development of en echelon faults and basins in the Hexi corridor. And the ectonic deformation of Alax and the North Qilian Mountains are almost simultaneous, which may be earlier than the initiation of en echelon basins in the Hexi Corridor and the faults between the en echelon basins. Calculated horizontal and vertical deformation rate are in agreement with geological data. The calculation of deformation process is helpful for understanding the geological evolution history of the northeastwards growth of the Tibetan Plateau.

Late quaternary climate, precipitation δ18O, and Indian monsoon variations over the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Li, Jingmin; Ehlers, Todd A.; Werner, Martin; Mutz, Sebastian G.; Steger, Christian; Paeth, Heiko

2017-01-01

The Himalaya-Tibet orogen contains one of the largest modern topographic and climate gradients on Earth. Proxy data from the region provide a basis for understanding Tibetan Plateau paleo climate and paleo elevation reconstructions. Paleo climate model comparisons to proxy data compliment sparsely located data and can improve climate reconstructions. This study investigates temporal changes in precipitation, temperature and precipitation δ18O (δO18p) over the Himalaya-Tibet from the Last Glacial Maximum (LGM) to present. We conduct a series of atmospheric General Circulation Model (GCM, ECHAM5-wiso) experiments at discrete time slices including a Pre-industrial (PI, Pre-1850 AD), Mid Holocene (MH, 6 ka BP) and LGM (21 ka BP) simulations. Model predictions are compared with existing proxy records. Model results show muted climate changes across the plateau during the MH and larger changes occurring during the LGM. During the LGM surface temperatures are ∼ 2.0- 4.0 °C lower across the Himalaya and Tibet, and >5.0 °C lower at the northwest and northeast edge of the Tibetan Plateau. LGM mean annual precipitation is 200-600 mm/yr lower over on the Tibetan Plateau. Model and proxy data comparison shows a good agreement for the LGM, but large differences for the MH. Large differences are also present between MH proxy studies near each other. The precipitation weighted annual mean δ18Op lapse rate at the Himalaya is about 0.4 ‰ /km larger during the MH and 0.2 ‰ /km smaller during the LGM than during the PI. Finally, rainfall associated with the continental Indian monsoon (between 70°E-110°E and 10°N-30°N) is about 44% less in the LGM than during PI times. The LGM monsoon period is about one month shorter than in PI times. Taken together, these results document significant spatial and temporal changes in temperature, precipitation, and δ18Op over the last ∼21 ka. These changes are large enough to impact interpretations of proxy data and the intensity of the Indian monsoon.

Fatty acid composition of intramuscular fat from pastoral yak and Tibetan sheep

USDA-ARS?s Scientific Manuscript database

Fatty acid (FA) composition of intramuscular fat from mature male yak (n=6) and mature Tibetan sheep (n=6) grazed on the same pasture in the Qinghai-Tibetan Plateau was analyzed by gas chromatograph/mass spectrometer to characterize fat composition of these species and to evaluate possible differenc...

Out of Tibet: Pliocene woolly rhino suggests high-plateau origin of Ice Age megaherbivores.

PubMed

Deng, Tao; Wang, Xiaoming; Fortelius, Mikael; Li, Qiang; Wang, Yang; Tseng, Zhijie J; Takeuchi, Gary T; Saylor, Joel E; Säilä, Laura K; Xie, Guangpu

2011-09-02

Ice Age megafauna have long been known to be associated with global cooling during the Pleistocene, and their adaptations to cold environments, such as large body size, long hair, and snow-sweeping structures, are best exemplified by the woolly mammoths and woolly rhinos. These traits were assumed to have evolved as a response to the ice sheet expansion. We report a new Pliocene mammal assemblage from a high-altitude basin in the western Himalayas, including a primitive woolly rhino. These new Tibetan fossils suggest that some megaherbivores first evolved in Tibet before the beginning of the Ice Age. The cold winters in high Tibet served as a habituation ground for the megaherbivores, which became preadapted for the Ice Age, successfully expanding to the Eurasian mammoth steppe.

Constraints on mountain building in the northeastern Tibet: Detrital zircon records from synorogenic deposits in the Yumen Basin

NASA Astrophysics Data System (ADS)

Wang, Weitao; Zhang, Peizhen; Yu, Jingxing; Wang, Yizhou; Zheng, Dewen; Zheng, Wenjun; Zhang, Huiping; Pang, Jianzhang

2016-06-01

The Cenozoic basins and ranges form the high topography of the northeastern Tibet that resulted from the India-Eurasia collision. Sedimentary rocks in the basins provide direct insight into the exhumation history of the ranges and the tectonic processes that led to the northeastward growth of the Tibetan Plateau. In this study, we analyzed and compared detrital zircon U-Pb ages from sands of modern rivers draining the Bei Shan, and North Qilian Shan and sandstones from the Yumen Basin. The zircon age distributions indicate that the strata dated to 24.2-16.7 Ma in the basin were derived from the Bei Shan, and the basin provenance changed rapidly to the North Qilian Shan terrane at ~16 Ma. These results suggest that an early stage of deformation along the Bei Shan at ~24 Ma was replaced by the growth of the North Qilian Shan at ~16 Ma. We conclude that the far-field effect associated with the Indo-Asian collision may result from Oligocene deformation in the Bei Shan, but the emergence of the North Qilian Shan at ~16 Ma could reflect the most recent outward growth of the Tibetan Plateau that may have been caused by the removal of some lithospheric mantle beneath central Tibet.

Assessing and mitigating uncertainties in the Noah-MP land-model simulations over the Tibet Plateau region

NASA Astrophysics Data System (ADS)

Zhang, G.; Chen, F.; Gan, Y.

2017-12-01

Assessing and mitigating uncertainties in the Noah-MP land-model simulations over the Tibet Plateau region Guo Zhang1, Fei Chen1,2, Yanjun Gan11State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China 2National Center for Atmospheric Research, Boulder, Colorado, USA Uncertainties in the Noah with multiparameterization (Noah-MP) land surface model were assessed through physics ensemble simulations for four sparsely-vegetated sites located in the Tibetan Plateau region. Those simulations were evaluated using observations at the four sites during the third Tibetan Plateau Experiment (TIPEX III).The impacts of uncertainties in precipitation data used as forcing conditions, parameterizations of sub-processes such as soil organic matter and rhizosphere on physics-ensemble simulations are identified using two different methods: the natural selection and Tukey's test. This study attempts to answer the following questions: 1) what is the relative contribution of precipitation-forcing uncertainty to the overall uncertainty range of Noah-MP simulations at those sites as compared to that at a more moisture and densely vegetated site; 2) what are the most sensitive physical parameterization for those sites; 3) can we identify the parameterizations that need to be improved? The investigation was conducted by evaluating simulated seasonal evolution of soil temperature, soilmoisture, surface heat fluxes through a number of Noah-MP ensemble simulations.

Geologic events coupled with Pleistocene climatic oscillations drove genetic variation of Omei treefrog (Rhacophorus omeimontis) in southern China.

PubMed

Li, Jun; Zhao, Mian; Wei, Shichao; Luo, Zhenhua; Wu, Hua

2015-12-21

Pleistocene climatic oscillations and historical geological events may both influence current patterns of genetic variation, and the species in southern China that faced unique climatic and topographical events have complex evolutionary histories. However, the relative contributions of climatic oscillations and geographical events to the genetic variation of these species remain undetermined. To investigate patterns of genetic variation and to test the hypotheses about the factors that shaped the distribution of this genetic variation in species of southern China, mitochondrial genes (cytochrome b and NADH dehydrogenase subunit 2) and nine microsatellite loci of the Omei tree frog (Rhacophorus omeimontis) were amplified in this study. The genetic diversity in the populations of R. omeimontis was high. The phylogenetic trees reconstructed from the mitochondrial DNA (mtDNA) haplotypes and the Bayesian genetic clustering analysis based on microsatellite data both revealed that all populations were divided into three lineages (SC, HG and YN). The two most recent splitting events among the lineages coincided with recent geological events (including the intense uplift of the Qinghai-Tibet Plateau, QTP and the subsequent movements of the Yun-Gui Plateau, YGP) and the Pleistocene glaciations. Significant expansion signals were not detected in mismatch analyses or neutrality tests. And the effective population size of each lineage was stable during the Pleistocene. Based on the results of this study, complex geological events (the recent dramatic uplift of the QTP and the subsequent movements of the YGP) and the Pleistocene glaciations were apparent drivers of the rapid divergence of the R. omeimontis lineages. Each diverged lineages survived in situ with limited gene exchanges, and the stable demographics of lineages indicate that the Pleistocene climatic oscillations were inconsequential for this species. The analysis of genetic variation in populations of R. omeimontis contributes to the understanding of the effects of changes in climate and of geographical events on the dynamic development of contemporary patterns of genetic variation in the species of southern China.

Characterizations of geothermal springs along the Moxi deep fault in the western Sichuan plateau, China

NASA Astrophysics Data System (ADS)

Qi, Jihong; Xu, Mo; An, Chengjiao; Wu, Mingliang; Zhang, Yunhui; Li, Xiao; Zhang, Qiang; Lu, Guoping

2017-02-01

Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The approach of hot spring variation research also has potential benefits for earthquake monitoring and prediction.

Regional environmental change and human activity over the past hundred years recorded in the sedimentary record of Lake Qinghai, China.

PubMed

Sha, ZhanJiang; Wang, Qiugui; Wang, Jinlong; Du, Jinzhou; Hu, Jufang; Ma, Yujun; Kong, Fancui; Wang, Zhuan

2017-04-01

Environmental change and human activity can be recorded in sediment cores in aquatic systems such as lakes. Information from such records may be useful for environmental governance in the future. Six sediment cores were collected from Lake Qinghai, China and its sublakes during 2012 and 2013. Measurements of sediment grain-size fractions indicate that sedimentation in the north and southwest of Lake Qinghai is dominated by river input, whereas that in Lake Gahai and Lake Erhai is dominated by dunes. The sedimentation rates in Lake Qinghai were calculated to be 0.101-0.159 cm/y, similar to the rates in other lakes on the Qinghai-Tibetan Plateau. Using these data and sedimentation rates from the literature, we compiled the spatial distribution of sedimentation rates. Higher values were obtained in the three main areas of Lake Qinghai: two in river estuaries and one close to sand dunes. Lower values were measured in the center and south of the lake. Measurements of total organic carbon (TOC), total nitrogen (TN), phosphorus concentrations, and TOC/TN ratios in three cores (QH01, QH02, and Z04) revealed four horizons corresponding to times of increased human activity. These anthropogenic events were (1) the development of large areas of cropland in the Lake Qinghai watershed in 1960, (2) the beginning of nationwide fertilizer use and increases in cropland area in the lake watershed after 1970, (3) the implementation of the national program "Grain to Green," and (4) the rapid increase in the tourism industry from 2000. Profiles of Rb, Sr concentrations, the Rb/Sr ratio, and grain-size fraction in core Z04 indicate that the climate has become drier over the past 100 years. Therefore, we suggest that lake sediments such as those in Lake Qinghai are useful media for high-resolution studies of regional environmental change and human activity.

Hydrochemistry and controlling mechanism of lakes in permafrost regions along the Qinghai-Tibet Engineering Corridor, China

NASA Astrophysics Data System (ADS)

Gao, Zeyong; Lin, Zhanju; Niu, Fujun; Luo, Jing; Liu, Minghao; Yin, Guoan

2017-11-01

Lakes are the main water resource for migrating animals and herdsmen in permafrost regions along the Qinghai-Tibet Engineering Corridor (QTEC) and play a crucial role in regulating the balance between regional surface water and groundwater. Hydrochemical properties also affect the soil environment, ecological conditions, and hydrological cycle. In this study, 127 water samples were collected from lakes to analyze hydrochemistry characteristics. The results are discussed in the context of relationships between water chemistry and local conditions including climate, topography, and geology. The results showed that 43.3% of lakes are fresh, 19.7% are brackish, 18.9% are saline, 17.3% are brine, and only 0.8% are bitter. The dominant cation is Na+, followed by Mg2 +, Ca2 +, and K+. The dominant anion is Cl-, followed by SO42 - and HCO3- in the northern section of study region; whereas Ca2 +, Na+, and HCO3- are the dominant ions in the lakes of the southern section. The higher concentrations of carbonate in the southern lakes reflect contributions from groundwater discharge. In contrast, the higher concentrations of sodium, chloride, and sulfate in the northern section indicate that they are dominated by the interaction of evaporates. Additionally, cation exchange, precipitation, and dissolution have also modified the distribution of hydrochemical compositions. Thermokarst processes, in particular, have induced changes in the hydrochemistry of lake waters in the permafrost regions of the QTEC, in that the ion concentrations are closely related to ground ice content. In the context of persistent climatic warming and steadily increasing anthropogenic activities, the salinity of lakes along the QTEC is likely to increase in the future.

Comparison of methanogen diversity of yak (Bos grunniens) and cattle (Bos taurus) from the Qinghai-Tibetan plateau, China.

PubMed

Huang, Xiao Dan; Tan, Hui Yin; Long, Ruijun; Liang, Juan Boo; Wright, André-Denis G

2012-10-19

Methane emissions by methanogen from livestock ruminants have significantly contributed to the agricultural greenhouse gas effect. It is worthwhile to compare methanogen from "energy-saving" animal (yak) and normal animal (cattle) in order to investigate the link between methanogen structure and low methane production. Diversity of methanogens from the yak and cattle rumen was investigated by analysis of 16S rRNA gene sequences from rumen digesta samples from four yaks (209 clones) and four cattle (205 clones) from the Qinghai-Tibetan Plateau area (QTP). Overall, a total of 414 clones (i.e. sequences) were examined and assigned to 95 operational taxonomic units (OTUs) using MOTHUR, based upon a 98% species-level identity criterion. Forty-six OTUs were unique to the yak clone library and 34 OTUs were unique to the cattle clone library, while 15 OTUs were found in both libraries. Of the 95 OTUs, 93 putative new species were identified. Sequences belonging to the Thermoplasmatales-affiliated Linage C (TALC) were found to dominate in both libraries, accounting for 80.9% and 62.9% of the sequences from the yak and cattle clone libraries, respectively. Sequences belonging to the Methanobacteriales represented the second largest clade in both libraries. However, Methanobrevibacter wolinii (QTPC 110) was only found in the cattle library. The number of clones from the order Methanomicrobiales was greater in cattle than in the yak clone library. Although the Shannon index value indicated similar diversity between the two libraries, the Libshuff analysis indicated that the methanogen community structure of the yak was significantly different than those from cattle. This study revealed for the first time the molecular diversity of methanogen community in yaks and cattle in Qinghai-Tibetan Plateau area in China. From the analysis, we conclude that yaks have a unique rumen microbial ecosystem that is significantly different from that of cattle, this may also help to explain why yak produce less methane than cattle.

Comparison of methanogen diversity of yak (Bos grunniens) and cattle (Bos taurus) from the Qinghai-Tibetan plateau, China

PubMed Central

2012-01-01

Background Methane emissions by methanogen from livestock ruminants have significantly contributed to the agricultural greenhouse gas effect. It is worthwhile to compare methanogen from “energy-saving” animal (yak) and normal animal (cattle) in order to investigate the link between methanogen structure and low methane production. Results Diversity of methanogens from the yak and cattle rumen was investigated by analysis of 16S rRNA gene sequences from rumen digesta samples from four yaks (209 clones) and four cattle (205 clones) from the Qinghai-Tibetan Plateau area (QTP). Overall, a total of 414 clones (i.e. sequences) were examined and assigned to 95 operational taxonomic units (OTUs) using MOTHUR, based upon a 98% species-level identity criterion. Forty-six OTUs were unique to the yak clone library and 34 OTUs were unique to the cattle clone library, while 15 OTUs were found in both libraries. Of the 95 OTUs, 93 putative new species were identified. Sequences belonging to the Thermoplasmatales-affiliated Linage C (TALC) were found to dominate in both libraries, accounting for 80.9% and 62.9% of the sequences from the yak and cattle clone libraries, respectively. Sequences belonging to the Methanobacteriales represented the second largest clade in both libraries. However, Methanobrevibacter wolinii (QTPC 110) was only found in the cattle library. The number of clones from the order Methanomicrobiales was greater in cattle than in the yak clone library. Although the Shannon index value indicated similar diversity between the two libraries, the Libshuff analysis indicated that the methanogen community structure of the yak was significantly different than those from cattle. Conclusion This study revealed for the first time the molecular diversity of methanogen community in yaks and cattle in Qinghai-Tibetan Plateau area in China. From the analysis, we conclude that yaks have a unique rumen microbial ecosystem that is significantly different from that of cattle, this may also help to explain why yak produce less methane than cattle. PMID:23078429

[Simulation on the seasonal growth patterns of grassland plant communities in northern China].

PubMed

Zhang, Li; Zheng, Yuan-Run

2008-10-01

Soil moisture is the key factor limiting the productivity of grassland in northern China ranging from arid to subhumid arid regions. In this paper, the seasonal and annual growth, foliage projective cover (FPC), evaporative coefficient (k), and net primary productivity (NPP) of 7 types of grasslands in North China were simulated by using a simple model based on well established ecological processes of water balance and climatic data collected at 460 sites over 40 years. The observed NPPs were used to validate the model, and the simulated NPPs were in high agreement with the observed NPPs. The simulated k, NPP, and FPC deceased from east to west in temperate grasslands, and decreased from southeast to northwest in Qinghai-Tibet Plateau, reflecting the moisture gradient in northern China. Alpine meadow had the highest k, NPP, and FPC in the 7 types of grasslands, alpine steppe had the second highest FPC but with a NPP similar to that of temperate steppe, and the three simulated parameters of temperate desert were the smallest. The simulated results suggested that the livestock density should be lower than 5.2, 2.3, 3.6, 2.1, 1.0, 0.6, and 0.2 sheep unit x hm(-2), while the coverage of rehabilitated vegetation should be about 93%, 79%, 56%, 50%, 44%, 38%, and 37% in alpine meadow, alpine steppe, temperate meadow steppe, temperate steppe, temperate desert steppe, temperate steppe desert, and temperate desert, respectively.

Expression of Stipa purpurea SpCIPK26 in Arabidopsis thaliana Enhances Salt and Drought Tolerance and Regulates Abscisic Acid Signaling

PubMed Central

Zhou, Yanli; Sun, Xudong; Yang, Yunqiang; Li, Xiong; Cheng, Ying; Yang, Yongping

2016-01-01

Stipa purpurea (S. purpurea) is the dominant plant species in the alpine steppe of the Qinghai-Tibet Plateau, China. It is highly resistant to cold and drought conditions. However, the underlying mechanisms regulating the stress tolerance are unknown. In this study, a CIPK gene from S. purpurea (SpCIPK26) was isolated. The SpCIPK26 coding region consisted of 1392 bp that encoded 464 amino acids. The protein has a highly conserved catalytic structure and regulatory domain. The expression of SpCIPK26 was induced by drought and salt stress. SpCIPK26 overexpression in Arabidopsis thaliana (A. thaliana) plants provided increased tolerance to drought and salt stress in an abscisic acid (ABA)-dependent manner. Compared with wild-type A. thaliana plants, SpCIPK26-overexpressing plants had higher survival rates, water potentials, and photosynthetic efficiency (Fv/Fm), as well as lower levels of reactive oxygen species (ROS) following exposure to drought and salt stress. Gene expression analyses indicated stress-inducible genes (RD29A, RD29B, and ABF2) and a ROS-scavenger gene (CAT1) were upregulated in SpCIPK26-overexpressing plants after stress treatments. All of these marker genes are associated with ABA-responsive cis-acting elements. Additionally, the similarities in the gene expression patterns following ABA, mannitol, and NaCl treatments suggest SpCIPK26 has an important role during plant responses to drought and salt stress and in regulating ABA signaling. PMID:27338368

[Status of wild resource of medicine plant Lamiophlomis rotata and its problems in sustainable use].

PubMed

Sun, Hui; Jiang, Shun-Yuan; Feng, Cheng-Qiang; Zhou, Yi; Gong, Yi; Wan, Ling-Yun; Li, Zhi

2012-11-01

Lamiophlomis rotata is a common wild herb in Tibetan traditional medicine with important medicinal and economic value. The paper examines the wild distributions, exploitation regime, and situations. A variety of research methods, such as literature survey, specimens inspection, market information collection in major Chinese herbal markets, questionnaire of herbalists and employers of local governments and institutions, and field quadrat survey and AcrGIS as well, have been used for this work. Total stock of wild resources of L. rotata is ranging from 3 713.49 tons to 6 896.56 tons (2 519-3 314 t in Qinghai, 490-1 414 t in Gansu, 641-1 167 t in Sichuan, and 422-999 t in Tibet, respectively), acceptable harvest quantity of the herb is ranging from 908-1 675 t per year, and actual harvest quantity is 2 520 t annually far beyond the acceptable harvest quantity. Harvesting quantity of L. rotata is far more than that of acceptable, suggesting that utilization pattern of this wild resource plant is unsustainable. L. rotata seems to act as an indicating plant of degraded ecosystem of high-altitude grassland, shrub grassland, and wetland, and distributes in those degraded and degrading plateau ecosystems, and the plant is facing with pressure of ecological protection and wild resource population degradation. Wild population monitoring and standard cultivation are of importance for although they are far from implementation due to shortage of related basic studies.

Gut microbiota may predict host divergence time during Glires evolution.

PubMed

Li, Huan; Qu, Jiapeng; Li, Tongtong; Yao, Minjie; Li, Jiaying; Li, Xiangzhen

2017-03-01

The gut microbial communities of animals play key roles in host evolution. However, the possible relationship between gut microbiota and host divergence time remains unknown. Here, we investigated the gut microbiota of eight Glires species (four lagomorph species and four rodent species) distributed throughout the Qinghai-Tibet plateau and Inner Mongolia grassland. Lagomorphs and rodents had distinct gut microbial compositions. Three out of four lagomorph species were dominated by Firmicutes, while rodents were dominated by Bacteroidetes in general. The alpha diversity values (Shannon diversity and evenness) exhibited significant differences between any two species within the lagomorphs, whereas there were no significant differences among rodents. The structure of the gut microbiota showed significant differences between lagomorphs and rodents. In addition, we calculated host phylogeny and divergence times, and used a phylogenetic approach to reconstruct how the animal gut microbiota has diverged from their ancestral species. Some core bacterial genera (e.g. Prevotella and Clostridium) shared by more than nine-tenths of all the Glires individuals associated with plant polysaccharide degradation showed marked changes within lagomorphs. Differences in Glires gut microbiota (based on weighted UniFrac and Bray-Curtis dissimilarity metrics) were positively correlated with host divergence time. Our results thus suggest the gut microbial composition is associated with host phylogeny, and further suggest that dissimilarity of animal gut microbiota may predict host divergence time. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Monitoring potential geographical distribution of four wild bird species in China

NASA Astrophysics Data System (ADS)

Dai, S.; Feng, D.; Xu, B.

2015-12-01

The outbreak of highly pathogenic avian influenza (HPAI) of the H5N1 subtype in wild birds and poultry have caught worldwide attention. To explore the association between wild bird migration and avian influenza virus transmission, we monitored potential geographical distribution of four wild bird species that might carry the avian influenza viruses in China. They are Bar-headed geese (Anser indicus), Ruddy Shelduck (Tadorna ferruginea), Whooper Swan (Cygnus cygnus) and Black-headed Gull (Larus ridibundus). They served as major reservoir of the avian influenza viruses. We used bird watching records with the precise latitude/longitude coordinates from January 2002 to August 2014, and environmental variables with a pixel resolution of 5 km × 5 km from 2002 to 2014. The study utilized maximum entropy (MaxEnt) model based on ecological niche model approaches, and got the following results: 1) MaxEnt model have good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.86-0.97; 2) The four wild bird species were estimated to concentrate in the North China Plain, the middle and lower region of the Yangtze River, Qinghai Lake, Tianshan Mountain and Tarim Basin, part of Tibet Plateau, and Hengduan Mountains; 3) Radiation and the minimum temperature were found to provide the most significant information. Our findings will help to understand the spread of avian influenza viruses by wild bird migration in China, which benefits for effective monitoring strategies and prevention measures.

The roles of calving migration and climate change in the formation of the weak genetic structure in the Tibetan antelope (Pantholops hodgsonii).

PubMed

Chen, Jiarui; Lin, Gonghua; Qin, Wen; Yan, Jingyan; Zhang, Tongzuo; Su, Jianping

2018-05-31

Geographical barriers and distance can reduce gene exchange among animals, resulting in genetic divergence of geographically isolated populations. The habitats of Tibetan antelope (Pantholops hodgsonii) has a geographical range of approximately 1,600 km across the Qinghai-Tibet Plateau (QTP) with a series tall mountains and big rivers. However, previously studies indicated that there was little genetic differentiation among their geographically delineated populations. To better understand the genetic structure of P. hodgsonii populations, we collected 145 samples from the three major calving regions considering their various calving grounds and migration routes. We used a combination of mitochondrial sequences (Cyt b, ATPase, D-loop and COX I) to investigate the genetic structure and the evolutionary divergence of the populations. Significant, albeit weak, genetic differentiation was detected among the three geographical populations. Analysis of the genetic divergence process revealed that the animals gradually entered into a period of rapid genetic differentiation since approximately 60,000 years ago. The calving migration of P. hodgsonii cannot be the main cause of their weak genetic structure since such cannot fully homogenize the genetic pool. Instead, the geological and climatic events as well as the coupling vegetation succession process during this period have been suggested to greatly contribute to the genetic structure and the expansion of genetic diversity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Selection by pollinators on floral traits in generalized Trollius ranunculoides (Ranunculaceae) along altitudinal gradients.

PubMed

Zhao, Zhi-Gang; Wang, Yi-Ke

2015-01-01

Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators.

Selection by Pollinators on Floral Traits in Generalized Trollius ranunculoides (Ranunculaceae) along Altitudinal Gradients

PubMed Central

Zhao, Zhi-Gang; Wang, Yi-Ke

2015-01-01

Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators. PMID:25692295

20 years in Tibet- The INDEPTH Transect

NASA Astrophysics Data System (ADS)

Brown, L. D.; Zhao, W.

2011-12-01

In 1991 a relatively small group of Chinese and U.S. scientists met to plan a modest set of geophysical surveys in the Himalaya of southern Tibet. The success of those pilot experiments developed into Project INDEPTH (INternational DEep Profiling of Tibet and the Himalaya), a major interdisciplinary, multinational effort to traverse the entire Himalaya-Tibet collision zone. With the recent completion of Phase IV, a series of geophysical and geological investigations across the boundary between the Tibet Plateau and the Qaidam Basin, Project INDEPTH has now largely fulfilled its initial vision. U.S. interest in deep reflection profiling of the Himalaya was stimulated in the late 70's by COCORP's success in mapping crustal scale, low-angle thrust faulting in the Appalachians of the SE U.S., and participation by COCORP scientists in several conferences in China that addressed Tibet in the early 80's. An informal meeting of Chinese, U.S., British and German scientists at the 1987 IASPEI meeting in Vancouver, Canada resulted in a formal invitation from Prof. Zhao Wenjin of the Chinese Academy of Geological Sciences for an international scouting party to visit Tibet in 1991 to assess the feasibility of crustal reflection profiling in the Himalaya. The report of that scouting party led to proposals to the U.S. National Science Foundation (Continental Dynamics Program) and the Chinese National Natural Science Foundation and Ministry of Geology and Mineral Resources to carry out a test survey of multichannel reflection profiling in the Himalayas, an experiment that came to be known as Phase I.. The dramatic success of Phase I in tracing the Main Himalayan detachment to depth launched the program's ambitious goal of traversing the entire Himalaya-Tibet Plateau collision zone. Along the way, INDEPTH grew from a simple test of the reflection method to a complex, multidisciplinary program that proved especially effective at integrating active and passive seismology with magnetotelluric techniques to characterize one of the earth's truly unique regions. While INDEPTH contributed a number of geoscientific "firsts", it also owes a great deal to the pioneering works that preceded it, particularly the 1981-1982 Sino-French expeditions and the 1985 Sino-British traverse, as well as key contributions from a number of individual Chinese and non-Chinese scientists who helped refine the evolving objectives of INDEPTH. Finally, whatever success INDEPTH has had is largely due the spirit of cooperation that grew out of the mutual trust that developed between the scientists of China, the U.S., Germany, Canada, Ireland, and Britain who faced many challenges over the course of this project.

Plunder behind the bamboo curtain. [Environmental effects of mining and deforestation in Tibet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denniston, D.

Significant environmental degradation has occurred in Tibet as China has stripped forests and minerals from the ground. Uranium, borax, lithium, copper, iron, chromite are all being exploited. High pasture is being overgrazed because fertile valleys are being inhabited by workers. Shortages of timber and paper pulp in China have meant cutting of dense stands of spruce, fir, larch, oak maple, and pine. Ground and surface waters are contaminated from mining, severe erosion is increasing from deforestation, overgrazing and mining on the high plateau. Importation of large numbers of Chinese workers has further threatened the Tibetian culture.

Loess sedimentation in Tibet: provenance, processes, and link with Quaternary glaciations

USGS Publications Warehouse

Sun, Jielun; Li, S.-H.; Muhs, D.R.; Li, B.

2007-01-01

Well-preserved loess deposits are found on the foothills of mountains along the middle reaches of the Yarlung Zangbo River in southern Tibet. Optically stimulated luminescence (OSL) dating is used to determine loess ages by applying the single-aliquot regeneration technique. Geochemical, mineralogical, and granulometric measurements were carried out to allow a comparison between loess from Tibet and the Chinese Loess Plateau. Our results demonstrate that (i) the loess deposits have a basal age of 13-11 ka, suggesting they accumulated after the last deglaciation, (ii) loess in southern Tibet has a "glacial" origin, resulting from eolian sorting of glaciofluvial outwash deposits from braided river channels or alluvial fans by local near-surface winds, and (iii) the present loess in the interior of Tibet has accumulated since the last deglaciation when increased monsoonal circulation provided an increased vegetation cover that was sufficient for trapping eolian silt. The lack of full-glacial loess is either due to minimal vegetation cover or possibly due to the erosion of loess as glaciofluvial outwash during the beginning of each interglacial. Such processes would have been repeated during each glacial-interglacial cycle of the Quaternary. ?? 2007 Elsevier Ltd. All rights reserved.

A Grammar of Bao'an Tu, a Mongolic Language of Northwest China

ERIC Educational Resources Information Center

Fried, Robert Wayne

2010-01-01

The present study is a grammatical overview of the Bao'an Tu language (one of the varieties included in the designation "ISO6393-3:PEH", also known as "Tongren Monguor", "Southwestern Monguor", or "Tongren Tu"). Bao'an Tu is spoken by approximately 4,000 people who live on the Qinghai-Tibetan Plateau in…

Himalayan uplift shaped biomes in Miocene temperate Asia: evidence from leguminous Caragana

Treesearch

Ming-Li Zhang; Xiao-Guo Xiang; Juan-Juan Xue; Stewart C. Sanderson; Peter W. Fritsch

2016-01-01

Caragana, with distinctive variation in leaf and rachis characters, exhibits three centers of geographic distribution, i.e., Central Asia, the Qinghai-Tibetan Plateau (QTP), and East Asia, corresponding to distinct biomes. Because Caragana species are often ecologically dominant components of the vegetation in these regions, it is regarded as a key taxon for...

Low crustal velocities and mantle lithospheric variations in southern Tibet from regional Pnl waveforms

NASA Astrophysics Data System (ADS)

Rodgers, Arthur J.; Schwartz, Susan Y.

We report low average crustal P-wave velocities (5.9-6.1 km/s, Poisson's ratio 0.23-0.27, thickness 68-76 km) in southern Tibet from modelling regional Pnl waveforms recorded by the 1991-1992 Tibetan Plateau Experiment. We also find that the mantle lithosphere beneath the Indus-Tsangpo Suture and the Lhasa Terrane is shield-like (Pn velocity 8.20-8.25 km/s, lid thickness 80-140 km, positive velocity gradient 0.0015-0.0025 s-1). Analysis of relative Pn travel time residuals requires a decrease in the mantle velocities beneath the northern Lhasa Terrane, the Banggong-Nujiang Suture and the southern Qiangtang Terrane. Tectonic and petrologic considerations suggest that low bulk crustal velocities could result from a thick (50-60 km) felsic upper crust with vertically limited and laterally pervasive partial melt. These results are consistent with underthrusting of Indian Shield lithosphere beneath the Tibetan Plateau to at least the central Lhasa Terrane.

Estimation of sub-pixel water area on Tibet plateau using multiple endmembers spectral mixture spectral analysis from MODIS data

NASA Astrophysics Data System (ADS)

Cui, Qian; Shi, Jiancheng; Xu, Yuanliu

2011-12-01

Water is the basic needs for human society, and the determining factor of stability of ecosystem as well. There are lots of lakes on Tibet Plateau, which will lead to flood and mudslide when the water expands sharply. At present, water area is extracted from TM or SPOT data for their high spatial resolution; however, their temporal resolution is insufficient. MODIS data have high temporal resolution and broad coverage. So it is valuable resource for detecting the change of water area. Because of its low spatial resolution, mixed-pixels are common. In this paper, four spectral libraries are built using MOD09A1 product, based on that, water body is extracted in sub-pixels utilizing Multiple Endmembers Spectral Mixture Analysis (MESMA) using MODIS daily reflectance data MOD09GA. The unmixed result is comparing with contemporaneous TM data and it is proved that this method has high accuracy.

Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data

USGS Publications Warehouse

Unsworth, M.J.; Jones, A.G.; Wei, W.; Marquis, G.; Gokarn, S.G.; Spratt, J.E.; Bedrosian, P.; Booker, J.; Leshou, C.; Clarke, G.; Shenghui, L.; Chanhong, L.; Ming, D.; Sheng, J.; Solon, K.; Handong, T.; Ledo, J.; Roberts, B.

2005-01-01

The Cenozoic collision between the Indian and Asian continents formed the Tibetan plateau, beginning about 70 million years ago. Since this time, at least 1,400 km of convergence has been accommodated by a combination of underthrusting of Indian and Asian lithosphere, crustal shortening, horizontal extrusion and lithospheric delamination. Rocks exposed in the Himalaya show evidence of crustal melting and are thought to have been exhumed by rapid erosion and climatically forced crustal flow. Magnetotelluric data can be used to image subsurface electrical resistivity, a parameter sensitive to the presence of interconnected fluids in the host rock matrix, even at low volume fractions. Here we present magnetotelluric data from the Tibetan-Himalayan orogen from 77??E to 92??E, which show that low resistivity, interpreted as a partially molten layer, is present along at least 1,000 km of the southern margin of the Tibetan plateau. The inferred low viscosity of this layer is consistent with the development of climatically forced crustal flow in Southern Tibet. ?? 2005 Nature Publishing Group.

Quantitative precipitation estimates for the northeastern Qinghai-Tibetan Plateau over the last 18,000 years

NASA Astrophysics Data System (ADS)

Li, Jianyong; Dodson, John; Yan, Hong; Cheng, Bo; Zhang, Xiaojian; Xu, Qinghai; Ni, Jian; Lu, Fengyan

2017-05-01

Quantitative information regarding the long-term variability of precipitation and vegetation during the period covering both the Late Glacial and the Holocene on the Qinghai-Tibetan Plateau (QTP) is scarce. Herein, we provide new and numerical reconstructions for annual mean precipitation (PANN) and vegetation history over the last 18,000 years using high-resolution pollen data from Lakes Dalianhai and Qinghai on the northeastern QTP. Hitherto, five calibration techniques including weighted averaging, weighted average-partial least squares regression, modern analogue technique, locally weighted weighted averaging regression, and maximum likelihood were first employed to construct robust inference models and to produce reliable PANN estimates on the QTP. The biomization method was applied for reconstructing the vegetation dynamics. The study area was dominated by steppe and characterized with a highly variable, relatively dry climate at 18,000-11,000 cal years B.P. PANN increased since the early Holocene, obtained a maximum at 8000-3000 cal years B.P. with coniferous-temperate mixed forest as the dominant biome, and thereafter declined to present. The PANN reconstructions are broadly consistent with other proxy-based paleoclimatic records from the northeastern QTP and the northern region of monsoonal China. The possible mechanisms behind the precipitation changes may be tentatively attributed to the internal feedback processes of higher latitude (e.g., North Atlantic) and lower latitude (e.g., subtropical monsoon) competing climatic regimes, which are primarily modulated by solar energy output as the external driving force. These findings may provide important insights into understanding the future Asian precipitation dynamics under the projected global warming.

Crustal anisotropy across eastern Tibet and surroundings modeled as a depth-dependent tilted hexagonally symmetric medium

NASA Astrophysics Data System (ADS)

Xie, Jiayi; Ritzwoller, Michael H.; Shen, Weisen; Wang, Weitao

2017-04-01

Two types of surface wave anisotropy are observed regularly by seismologists but are only rarely interpreted jointly: apparent radial anisotropy, which is the difference in propagation speed between horizontally and vertically polarized waves inferred from Love and Rayleigh waves, and apparent azimuthal anisotropy, which is the directional dependence of surface wave speeds (usually Rayleigh waves). We show that a new data set of Love and Rayleigh wave isotropic phase speeds and Rayleigh wave azimuthal anisotropy observed within and surrounding eastern Tibet can be explained simultaneously by modeling the crust as a depth-dependent tilted hexagonally symmetric (THS) medium. We specify the THS medium with depth-dependent hexagonally symmetric elastic tensors tilted and rotated through dip and strike angles and estimate these quantities using a Bayesian Monte Carlo inversion to produce a 3-D model of the crust and uppermost mantle on a 0.5° × 0.5° spatial grid. In the interior of eastern Tibet and in the Yunnan-Guizhou plateau, we infer a steeply dipping THS upper crustal medium overlying a shallowly dipping THS medium in the middle-to-lower crust. Such vertical stratification of anisotropy may reflect a brittle to ductile transition in which shallow fractures and faults control upper crustal anisotropy and the crystal-preferred orientation of anisotropic (perhaps micaceous) minerals governs the anisotropy of the deeper crust. In contrast, near the periphery of the Tibetan Plateau the anisotropic medium is steeply dipping throughout the entire crust, which may be caused by the reorientation of the symmetry axes of deeper crustal anisotropic minerals as crustal flows are rotated near the borders of Tibet.

Seperating Long-term Hydrological Loading and Tectonic Deformation Observed with Multi-temporal SAR Interferometry and GPS in Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

LI, G.; Lin, H.

2014-12-01

From 2000 till present, most endorheic lakes in Tibetan plateau experienced quick increasing. Several largest lakes, gathered several meters depth water during one decade. Such massive mass increasing will lead to elastic and visco-elastic deformation of the ground. Qinghai-Tibetan Plateau is one the most active tectonic places in the world; monitoring its ground deformation is essential, when loading effect is a nuisance item. Due to the sparse distribution of GPS sites and most are roving sites, it is hard to distinguish tectonic component from mass loading effect. In this research we took Selin Co Lake located at Nujiang-Bangoin suture zone and evaluated long time ground deformation at hundred kilometers scale by multi-temporal SAR interferometry and simulate the ground deformation by loading history evaluated by multi mission satellite altimetry and optical images observation. At Nujiang-Bangoin suture zone, where GPS presented the maximum ground subsidence in Qinghai-Tibetan Plateau of 3.6mm/a which was found at the shore of Selin Co Lake from 1999 to 2011, when it experienced water level increasing of 0.7m/a. A model of elastic plate lying over Newtonian viscous half-space matches well with the results of multi-temporal SAR interferometry and GPS observations. We concluded that near Selin Co Lake area, ground deformation is composed by both tectonic and hydrological loading part. As SAR image coverage is much smaller than tectonic scale, we contribute the deformation detected by InSAR to loading effect. After evaluating and removing the hydrological loading effect, we founds that Nujiang-Bangoin suture zone did not experience quick subsidence, but only limited to 0.5mm/a. Selin Co Lake's quick volume increasing caused 3mm/a subsidence rate to the nearest GPS site. The Second nearest site showed the 1.4mm/a subsidence totally, which were composed by 1.05mm/a hydrological loading effect and the rest was tectonic. We also found that Young's Modulus is the most essential parameter for loading effect simulation, and our simulation gave the similar Young's Modulus as the previous seismic tomographic INDEPTH III program did. Therefore with accurate seismic tomographic results and loading history detected by remote sensing could accurately simulate ground deformation caused by hydrological loading.

Studying Nomads on the Tibetan Plateau.

ERIC Educational Resources Information Center

Goldstein, Melvyn C.; Beall, Cynthia M.

1986-01-01

Noting that few western social scientists have been allowed to enter Tibet, this article describes the 5-month experience of 2 United States anthropologists. Included are 5 photographs of nomads, a description of the research conditions, and a collection of observations and tentative conclusions about these highland peoples (JDH)

Modelling and validation land-atmospheric heat fluxes by using classical surface parameters over the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Ma, W.; Ma, Y.; Hu, Z.; Zhong, L.

2017-12-01

In this study, a land-atmosphere model was initialized by ingesting AMSR-E products, and the results were compared with the default model configuration and with in situ long-term CAMP/Tibet observations. Firstly our field observation sites will be introduced based on ITPCAS (Institute of Tibetan Plateau Research, Chinese Academy of Sciences). Then, a land-atmosphere model was initialized by ingesting AMSR-E products, and the results were compared with the default model configuration and with in situ long-term CAMP/Tibet observations. The differences between the AMSR-E initialized model runs with the default model configuration and in situ data showed an apparent inconsistency in the model-simulated land surface heat fluxes. The results showed that the soil moisture was sensitive to the specific model configuration. To evaluate and verify the model stability, a long-term modeling study with AMSR-E soil moisture data ingestion was performed. Based on test simulations, AMSR-E data were assimilated into an atmospheric model for July and August 2007. The results showed that the land surface fluxes agreed well with both the in situ data and the results of the default model configuration. Therefore, the simulation can be used to retrieve land surface heat fluxes from an atmospheric model over the Tibetan Plateau.

Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China.

PubMed

Zhang, Kai; Su, Jing; Xiong, Xiong; Wu, Xiang; Wu, Chenxi; Liu, Jiantong

2016-12-01

Tibetan Plateau is known as the world's third pole, which is characterized by a low population density with very limited human activities. Tibetan Plateau possesses the greatest numbers of high-altitude inland lakes in the world. However, no information is currently available on the characteristic of microplastic pollution in those lakes within this remote area. In this work, lakeshore sediments from four lakes within the Siling Co basin in northern Tibet were sampled and examined for microplastics (<5 mm). Microplastics were detected in six out of seven sampling sites with abundances ranging from 8 ± 14 to 563 ± 1219 items/m 2 . Riverine input might have contributed to the high abundance of microplastics observed in this remote area. Morphological features suggest that microplastics are derived from the breakdown of daily used plastic products. Polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride were identified from the microplastic samples using laser Raman spectroscopy, and oxidative and mechanical weathering textures were observed on the surface of microplastics using scanning electron microscope. These results demonstrate the presence of microplastics even for inland lakes in remote areas under very low human impact, and microplastic pollution can be a global issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spiroides shrubs on Qinghai-Tibetan Plateau: Multilocus phylogeography and palaeodistributional reconstruction of Spiraea alpina and S. Mongolica (Rosaceae).

PubMed

Khan, Gulzar; Zhang, Faqi; Gao, Qingbo; Fu, Pengcheng; Zhang, Yu; Chen, Shilong

2018-06-01

A common hypothesis for the rich biodiversity found in mountains is uplift-driven diversification. Using a multilocus approach, here we assessed the influence of Qinghai-Tibetan Plateau (QTP) uplift and fluctuating regional climate on genetic diversity of two sister spiroides shrubs, Spiraea alpina and S. mongolica. Combined with palaeodistributional reconstruction modelling, we investigated the current and past-predicted distribution of these species under different climatic episodes. The study demonstrated that continuous pulses of retreat and expansion during last glacial-interglacial episodes, combined with the uplifting of QTP shaped the current distribution of these species. All the populations showed high level of genetic diversity based on both cpDNA and SSR markers. The average gene diversity within populations based on cpDNA markers was 0.383 ± 0.052 for S. alpina and 0.477 ± 0.048 for S. mongolica. The observed and expected heterozygosities based on SSR for both Spiraea alpina and S. mongolicawere H E (0.72-0.90)/H O (0.35-0.78) and H E (0.77-0.92)/H O (0.47-0.77) respectively. Palaeodistributional reconstruction indicated species' preferences at southeastern edge of the plateau during last glacial maximum, at higher altitude areas of QTP and range expansion to central plateau during the interglacial episodes. Assignment tests in STRUCTURE, discriminant analysis of principal coordinates and Immigrants analysis in GENECLASS based on nuclear SSR markers did not support the hypothesis of gene flow between both the species. However, maximum likelihood approach based on cpDNA showed sharing of haplotypes between both species. Copyright © 2018 Elsevier Inc. All rights reserved.

Rates and style of Cenozoic deformation around the Gonghe Basin, northeastern Tibetan Plateau

USGS Publications Warehouse

Craddock, William H.; Kirby, Eric; Zhang, Huiping; Clark, Marin K.; Champagnac, Jean-Daniel; Yuan, Daoyang

2014-01-01

The northeastern Tibetan Plateau constitutes a transitional region between the low-relief physiographic plateau to the south and the high-relief ranges of the Qilian Shan to the north. Cenozoic deformation across this margin of the plateau is associated with localized growth of fault-cored mountain ranges and associated basins. Herein, we combine detailed structural analysis of the geometry of range-bounding faults and deformation of foreland basin strata with geomorphic and exhumational records of erosion in hanging-wall ranges in order to investigate the magnitude, timing, and style of deformation along the two primary fault systems, the Qinghai Nan Shan and the Gonghe Nan Shan. Structural mapping shows that both ranges have developed above imbricate fans of listric thrust faults, which sole into décollements in the middle crust. Restoration of shortening along balanced cross sections suggests a minimum of 0.8–2.2 km and 5.1–6.9 km of shortening, respectively. Growth strata in the associated foreland basin record the onset of deformation on the two fault systems at ca. 6–10 Ma and ca. 7–10 Ma, respectively, and thus our analysis suggests late Cenozoic shortening rates of 0.2 +0.2/–0.1 km/m.y. and 0.7 +0.3/–0.2 km/m.y. along the north and south sides of Gonghe Basin. Along the Qinghai Nan Shan, these rates are similar to late Pleistocene slip rates of ∼0.10 ± 0.04 mm/yr, derived from restoration and dating of a deformed alluvial-fan surface. Collectively, our results imply that deformation along both flanks of the doubly vergent Qilian Shan–Nan Shan initiated by ca. 10 Ma and that subsequent shortening has been relatively steady since that time.

ASTER measurement of supraglacial lakes in the Mount Everest region of the Himalaya

USGS Publications Warehouse

Wessels, R.L.; Kargel, J.S.; Kieffer, H.H.

2002-01-01

We demonstrate an application of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images to detect and monitor supraglacial lakes on glaciers in the Mount Everest region in Tibet (Xizang) and Nepal. ASTER offers powerful capabilities to monitor supraglacial lakes in terms of (1) surface area, growth and disappearance (spatial resolution = 15 m), (2) turbidity (15 m resolution), and (3) temperature (90 m resolution). Preliminary results show an overall similarity of supraglacial lakes on three glaciers. Lakes have widely varying turbidity as indicated by color in visible/near-infrared bands 1-3, the largest lakes being bright blue (highly turbid), cold (near 0??C) and hydrautically connected with other lakes and supraglacial streams, while small lakes are mostly dark blue (relatively clear water), warmer (>4??C), and appear hydrautically isolated. High levels of turbidity in supraglacial lakes indicate high rates of meltwater input from streams or erosion of ice cliffs, and thus are an indirect measure relating to the activity and hydraulic integration of the lake with respect to other lakes and streams in the glacier.

Complex responses of spring vegetation growth to climate in a moisture-limited alpine meadow

PubMed Central

Ganjurjav, Hasbagan; Gao, Qingzhu; Schwartz, Mark W.; Zhu, Wenquan; Liang, Yan; Li, Yue; Wan, Yunfan; Cao, Xujuan; Williamson, Matthew A.; Jiangcun, Wangzha; Guo, Hongbao; Lin, Erda

2016-01-01

Since 2000, the phenology has advanced in some years and at some locations on the Qinghai-Tibetan Plateau, whereas it has been delayed in others. To understand the variations in spring vegetation growth in response to climate, we conducted both regional and experimental studies on the central Qinghai-Tibetan Plateau. We used the normalized difference vegetation index to identify correlations between climate and phenological greening, and found that greening correlated negatively with winter-spring time precipitation, but not with temperature. We used open top chambers to induce warming in an alpine meadow ecosystem from 2012 to 2014. Our results showed that in the early growing season, plant growth (represented by the net ecosystem CO2 exchange, NEE) was lower in the warmed plots than in the control plots. Late-season plant growth increased with warming relative to that under control conditions. These data suggest that the response of plant growth to warming is complex and non-intuitive in this system. Our results are consistent with the hypothesis that moisture limitation increases in early spring as temperature increases. The effects of moisture limitation on plant growth with increasing temperatures will have important ramifications for grazers in this system. PMID:26983697

Complex responses of spring vegetation growth to climate in a moisture-limited alpine meadow

NASA Astrophysics Data System (ADS)

Ganjurjav, Hasbagan; Gao, Qingzhu; Schwartz, Mark W.; Zhu, Wenquan; Liang, Yan; Li, Yue; Wan, Yunfan; Cao, Xujuan; Williamson, Matthew A.; Jiangcun, Wangzha; Guo, Hongbao; Lin, Erda

2016-03-01

Since 2000, the phenology has advanced in some years and at some locations on the Qinghai-Tibetan Plateau, whereas it has been delayed in others. To understand the variations in spring vegetation growth in response to climate, we conducted both regional and experimental studies on the central Qinghai-Tibetan Plateau. We used the normalized difference vegetation index to identify correlations between climate and phenological greening, and found that greening correlated negatively with winter-spring time precipitation, but not with temperature. We used open top chambers to induce warming in an alpine meadow ecosystem from 2012 to 2014. Our results showed that in the early growing season, plant growth (represented by the net ecosystem CO2 exchange, NEE) was lower in the warmed plots than in the control plots. Late-season plant growth increased with warming relative to that under control conditions. These data suggest that the response of plant growth to warming is complex and non-intuitive in this system. Our results are consistent with the hypothesis that moisture limitation increases in early spring as temperature increases. The effects of moisture limitation on plant growth with increasing temperatures will have important ramifications for grazers in this system.

Complex responses of spring vegetation growth to climate in a moisture-limited alpine meadow.

PubMed

Ganjurjav, Hasbagan; Gao, Qingzhu; Schwartz, Mark W; Zhu, Wenquan; Liang, Yan; Li, Yue; Wan, Yunfan; Cao, Xujuan; Williamson, Matthew A; Jiangcun, Wangzha; Guo, Hongbao; Lin, Erda

2016-03-17

Since 2000, the phenology has advanced in some years and at some locations on the Qinghai-Tibetan Plateau, whereas it has been delayed in others. To understand the variations in spring vegetation growth in response to climate, we conducted both regional and experimental studies on the central Qinghai-Tibetan Plateau. We used the normalized difference vegetation index to identify correlations between climate and phenological greening, and found that greening correlated negatively with winter-spring time precipitation, but not with temperature. We used open top chambers to induce warming in an alpine meadow ecosystem from 2012 to 2014. Our results showed that in the early growing season, plant growth (represented by the net ecosystem CO2 exchange, NEE) was lower in the warmed plots than in the control plots. Late-season plant growth increased with warming relative to that under control conditions. These data suggest that the response of plant growth to warming is complex and non-intuitive in this system. Our results are consistent with the hypothesis that moisture limitation increases in early spring as temperature increases. The effects of moisture limitation on plant growth with increasing temperatures will have important ramifications for grazers in this system.

[Effect of simulative warming on growth and antioxidative characteristics of Kobresia pygmaea and K. tibetica in the permafrost region of Qinghai-Tibetan Plateau, China].

PubMed

Xiao, Yao; Wang, Gen Xu; Yang, Yan; Yang, Yang; Peng, A Hui; Zhang, Li

2017-04-18

In the present study, open top chambers (OTCs) were employed to simulate temperature increase at Fenghuoshan site, located on the hinterland of Qinghai-Tibetan Plateau. To explore the potential response mechanism of alpine plants under warmer temperature, the leaf morphological and antioxidative characteristics of two dominant species of alpine meadow (Kobresia pygmaea) and alpine swamp meadow (K. tibetica) were analyzed. The results showed that length and numbers of leaves in K. pygmaea increased by 40.0% and 72.7% by warming, respectively. Plant height and leaf length in K. tibetica increased by 11.9% and 19.3% by warming, respectively. Warming improved plant growth and aboveground biomass accumulation in both species. However, warming did not affect leaf membrane permeability (electrolyte leakage), active oxygen species (hydrogen peroxide and superoxide anion), activities of superoxide dismutase, peroxidase, ascorbate peroxidase and catalase, and malondialdehyde content in both species. Ascorbic acid and free proline contents in K. tibetica increased by 29.8% and 53.8%, respectively, but no change was found in K. pygmaea. In conclusion, K. pygmaea and K. tibetica could adapt under warmer temperature through keeping a steady antioxidative status.

Physiological responses of Kobresia pygmaea to warming in Qinghai-Tibetan Plateau permafrost region

NASA Astrophysics Data System (ADS)

Yang, Y.; Wang, G. X.; Yang, L. D.; Guo, J. Y.; Li, N.

2012-02-01

Kobresia pygmaea (C. B. Clarke) C. B. Clarke is one dominant herbaceous species in the alpine meadows of the Qinghai-Tibetan Plateau. From 2006 to 2009, a warming experiment was conducted in this permafrost region. Two 2-year warming treatments with an annual average warming of 2.1 °C and 4.4 °C, and one 4-year warming treatment with an annual average warming of 2.3 °C were established to examine physiological responses of K. pygmaea to warming. Our results indicated that 2-years of warming increased malondialdehyde and non-structural carbohydrates in the plants. There was no effect of 2-year warming on electrolyte leakage and free proline content. In the 2-year warming treatment, superoxide dismutase activity and peroxidase activity increased, ascorbate peroxidase activity and ascorbic acid only increased in 2-year high warming treatment, whereas in the 4-year warming treatment, active oxygen species, electrolyte leakage, UV-absorbing compounds and anthocyanins decreased. The 4-year warming treatment also significantly increased non-structural carbonhydrate and free proline accumulation for osmotic adjustment. The results of this study suggest that K. pygmaea could adapt to a warmer environment in the future.

What drives the Tibetan crust to the South East Asia? Role of upper mantle density discontinuities as inferred from the continental geoid anomalies

NASA Astrophysics Data System (ADS)

Rajesh, S.

2012-04-01

The Himalaya-Tibet orogen formed as a result of the northward convergence of India into the Asia over the past 55 Ma had caused the north south crustal shortening and Cenozoic upliftment of the Tibetan plateau, which significantly affected the tectonic and climatic framework of the Asia. Geodetic measurements have also shown eastward crustal extrusion of Tibet, especially along major east-southeast strike slip faults at a slip rate of 15-20 mm a-1 and around 40 mm a-1. Such continental scale deformations have been modeled as block rotation by fault boundary stresses developed due to the India-Eurasia collision. However, the Thin Sheet model explained the crustal deformation mechanism by considering varying gravitational potential energy arise out of varying crustal thickness of the viscous lithosphere. The Channel Flow model, which also suggests extrusion is a boundary fault guided flow along the shallow crustal brittle-ductile regime. Although many models have proposed, but no consensus in these models to explain the dynamics of measured surface geodetic deformation of the Tibetan plateau. But what remains conspicuous is the origin of driving forces that cause the observed Tibetan crustal flow towards the South East Asia. Is the crustal flow originated only because of the differential stresses that developed in the shallow crustal brittle-ductile regime? Or should the stress transfer to the shallow crustal layers as a result of gravitational potential energy gradient driven upper mantle flow also to be accounted. In this work, I examine the role of latter in the light of depth distribution of continental geoid anomalies beneath the Himalaya-Tibet across major upper mantle density discontinuities. These discontinuity surfaces in the upper mantle are susceptible to hold the plastic deformation that may occur as a result of the density gradient driven flow. The distribution of geoid anomalies across these density discontinuities at 220, 410 and 660 km depth in the upper mantle beneath the Himalaya-Tibet has been studied by analyzing the geoid undulation data obtained from various satellite geodetic missions along with the recent and old (EGM2008 and EGM2006) Earth Gravity models. Results show that the net geoid anomaly varies from -65 m to -20 m, which signify a density stratified upper mantle beneath the Himalaya-Tibet and the same has been confirmed from the results of regional seismic tomography studies. The density anomaly distribution beneath Tibet from 163 km depth to its upper mantle thickness of 1063 km show a strong NW-SE elliptically oriented positive geoid anomalies of magnitude around 40 meter. Asymmetric density anomaly gradient have been observed along the Himalayan arc from west to east as well as across the arc from north to south. This caused differential gravitational potential gradient and hence an elliptical flow structure of the Tibetan continental mantle along the resultant NW-SE direction, which is in concurrence with the observed present day direction of the Tibetan crustal flow. Thus the geoid anomalies distributed at various depth ranges show how the gradient in the upper mantle gravitational potential energy, especially across the deformed discontinuity surface, is significant in determining the transfer of deviatoric stresses and providing traction to the flow of crustal layers of the Tibetan Plateau. This suggests the viscous flow model could be a preferable choice, which could better accommodate the dynamics of the upper mantle, in explaining the crustal extrusion processes of the Tibetan Plateau.

Observations of Quasi-Love Waves in Tibet Indicates Coherent Deformation of the Crust and Upper Mantle

NASA Astrophysics Data System (ADS)

Chen, X.; Park, J. J.

2012-12-01

The high uplift of the Tibet area is caused by the continental collision between the Indian plate and the Eurasian plate. The style of deformation along with the collision is still being debated, particularly whether the deformation is vertically coherent or not, i.e., whether the upper mantle deforms coherently with the crust. In this work, we have used quasi-Love (QL) waves to constrain the anisotropy pattern around the Tibet region. The existence of anisotropy gradients has been identified with the observations of QL waves, which is a converted Rayleigh-wave motion that follows the arrival of the Love wave. Further, the locations of the anisotropy gradients have been pinned with the delay time between the Love wave and the QL wave, which is determined from cross-correlation. Our results show that the frequency content of Tibetan QL wave is centered around 10 mHz, indicating the depth range of anisotropy should be in the asthenosphere. Most of the scatterers of QL wave that we can detect lie outside the Tibet Plateau. Their distribution correlates well with the boundary of the Persia-Tibet- Burma orogeny, which has been identified from surface geologic data. This correlation, between surface geology and upper mantle anisotropy inferred from QL observations at the orogenic boundary, suggests that the crust and upper mantle of the orogeny are deforming coherently. Other scatterers that are off the Persia-Tibet-Burma orogenic boundary mostly cluster in two locations, the Tarim Basin, and the Bangong-Nujiang Suture, where there could exist contrasting anisotropy patterns in the upper mantle. The deformation in the Tibet region is complicated, yet our research suggests a vertically coherent deformation style of the upper mantle in Tibet.

[Comparison of GIMMS and MODIS normalized vegetation index composite data for Qing-Hai-Tibet Plateau].

PubMed

Du, Jia-Qiang; Shu, Jian-Min; Wang, Yue-Hui; Li, Ying-Chang; Zhang, Lin-Bo; Guo, Yang

2014-02-01

Consistent NDVI time series are basic and prerequisite in long-term monitoring of land surface properties. Advanced very high resolution radiometer (AVHRR) measurements provide the longest records of continuous global satellite measurements sensitive to live green vegetation, and moderate resolution imaging spectroradiometer (MODIS) is more recent typical with high spatial and temporal resolution. Understanding the relationship between the AVHRR-derived NDVI and MODIS NDVI is critical to continued long-term monitoring of ecological resources. NDVI time series acquired by the global inventory modeling and mapping studies (GIMMS) and Terra MODIS were compared over the same time periods from 2000 to 2006 at four scales of Qinghai-Tibet Plateau (whole region, sub-region, biome and pixel) to assess the level of agreement in terms of absolute values and dynamic change by independently assessing the performance of GIMMS and MODIS NDVI and using 495 Landsat samples of 20 km x20 km covering major land cover type. High correlations existed between the two datasets at the four scales, indicating their mostly equal capability of capturing seasonal and monthly phenological variations (mostly at 0. 001 significance level). Simi- larities of the two datasets differed significantly among different vegetation types. The relative low correlation coefficients and large difference of NDVI value between the two datasets were found among dense vegetation types including broadleaf forest and needleleaf forest, yet the correlations were strong and the deviations were small in more homogeneous vegetation types, such as meadow, steppe and crop. 82% of study area was characterized by strong consistency between GIMMS and MODIS NDVI at pixel scale. In the Landsat NDVI vs. GIMMS and MODIS NDVI comparison of absolute values, the MODIS NDVI performed slightly better than GIMMS NDVI, whereas in the comparison of temporal change values, the GIMMS data set performed best. Similar with comparison results of GIMMS and MODIS NDVI, the consistency across the three datasets was clearly different among various vegetation types. In dynamic changes, differences between Landsat and MODIS NDVI were smaller than Landsat NDVI vs. GIMMS NDVI for forest, but Landsat and GIMMS NDVI agreed better for grass and crop. The results suggested that spatial patterns and dynamic trends of GIMMS NDVI were found to be in overall acceptable agreement with MODIS NDVI. It might be feasible to successfully integrate historical GIMMS and more recent MODIS NDVI to provide continuity of NDVI products. The accuracy of merging AVHRR historical data recorded with more modern MODIS NDVI data strongly depends on vegetation type, season and phenological period, and spatial scale. The integration of the two datasets for needleleaf forest, broadleaf forest, and for all vegetation types in the phenological transition periods in spring and autumn should be treated with caution.

The situation of hazardous chemical accidents in China between 2000 and 2006.

PubMed

Duan, Weili; Chen, Guohua; Ye, Qing; Chen, Qingguang

2011-02-28

From the aspects of the total quantity of accidents, regional inequality, enterprises scale and environmental pollution accidents, this study makes an analysis of hazardous chemical accidents in China for the period spanning from 2000 to 2006. The following results are obtained: firstly, there were lots of accidents and fatalities in hazardous chemical business, i.e., the number of casualty accidents fluctuated between 200 and 600/year, the number of fatality fluctuated between 220 and 1100/year. Secondly, the accident rate in developed southeast coastal areas, e.g., Guangdong, Zhejiang and Jiangsu, was far higher than that in the northwest regions, e.g., Xizang, Xinjiang, and Qinghai. Thirdly, nearly 80% of dangerous chemical accidents had occurred in small and medium-sized enterprises (SMEs). Finally, various sudden environmental pollution accidents resulted from hazardous chemicals were frequent in recent years, causing a huge damage to human and property. Then, based on the readjustment of economic structure in the last decades, the development status of Occupational Health and Safety (OHS) in SMEs and other factors, the paper explores the main causes, which offers valuable insight into measures that should be taken to reduce hazardous chemical accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

A synoptic view of the distribution and connectivity of the mid-crustal low velocity zone beneath Tibet

NASA Astrophysics Data System (ADS)

Yang, Y.; Zheng, Y.; Xie, Z.; Ritzwoller, M. H.

2011-12-01

The Tibetan Plateau results from the convergence between the Indian and Eurasian plates. However, the physical processes that have controlled the deformation history of Tibet, particularly the potential localization of deformation either in the vertical or horizontal directions remain subject to debate. There are a growing list and wide variety of observations that suggest that the Tibetan crust is warm and presumably ductile. Some of observations are often taken as prima facie evidence for the existence of partial melt or aqueous fluids in the middle or deep crust beneath Tibet and in some cases for the decoupling or partitioning of strain between the upper crust and uppermost mantle. However, most of this evidence is highly localized along nearly linear seismic or magneto-telluric profiles. This motivates the two questions addressed by this study. First, how pervasive across Tibet are the phenomena on which inferences of the existence of crustal partial melt rest? In particular, how pervasive are mid-crustal low velocity zones across Tibet? Second, what is the geometry or inter-connectivity of the crustal low velocity zones observed across Tibet? In this study, we address these questions by producing a new 3-D model of crustal and uppermost mantle shear wave speeds inferred from Rayleigh wave dispersion observed on cross-correlations of long time series of ambient seismic noise. Broadband seismic data from about 600 stations (Chinese Provincial networks, FDSN, several PASSCAL experiments including the INDEPTH IV experiment) yield about 50,000 inter-station paths, which are used to generate Rayleigh wave phase velocity maps from 10 sec to 50 sec period. The time series lengths in the cross-correlations range from 1 to 2 years in duration. The resulting Rayleigh wave phase velocity maps are inverted for a 3D Vsv model of crustal and upper most mantles. The major results from our model are summarized below: (1) A crustal LVZ exists across most of the high Tibetan Plateau. (2) The distribution of the amplitude of the LVZ is not uniform. In fact, the largest amplitudes (i.e., lowest mid-crustal shear wave speeds) are found predominantly around the periphery of Tibet. (3) The lateral distribution of strong LVZs are coincident with the distribution of strong radial anisotropy in the middle crust, suggesting LVZs of Vsv in the middle crust may be mostly due to the strong radial anisotropy rather than the presence of partial melt or aqueous fluids.

Progress on observation of cryospheric components and climate-related studies in China

NASA Astrophysics Data System (ADS)

Xiao, Cunde; Qin, Dahe; Yao, Tandong; Ding, Yongjian; Liu, Shiyin; Zhao, Lin; Liu, Yujie

2008-03-01

Systematic studies on the cryosphere in China started in the late 1950s. Significant achievements have been made by continuous investigation of glacier inventories, frozen ground observations, paleo-climate analyses of ice cores, process studies and the modeling of cryopsheric/atmospheric interactions. The general facts and understanding of these changes include: (1) Solid precipitation, including the number of days with frost and hail storms, shows a decreasing tendency over the past half century. (2) In most areas glaciers are retreating or have completely vanished (>80%), some glaciers are still advancing (5%-20% depending upon time period). The annual glacial melt water has been increasing since the 1980s. This increased supply of melt water to river runoff in Northwest China is about a 10%-13%. (3) The long-term variability of snow cover in western China is characterized by a large inter-annual variation superimposed on a small increasing trend. Snow cover variability in the Qinghai-Xizang Plateau (QXP) is influenced by the Indian monsoon, and conversely impacts monsoon onset and strength and eventually the drought and flood events in middle-low reaches of Yangtze River. (4) Frozen ground, including permafrost, is decaying both in QXP and in Northeast China. The most significant changes occurred in the regions with thickest seasonal frozen ground (SFG), i.e., inland QXP, then northeastern and northwestern QXP. The cold season air temperature is the main factor controlling SFG change. The increase of ground surface temperatures is more significant than air temperature. (5) The sea ice coverage over the Bohai Sea and Yellow Sea has deceased since the 1980s. (6) River ice duration and ice thickness is also decreasing in northern China. In 2001, the Chinese National Committee of World Climate Research Program/Climate and Cyosphere (WCRP/CliC) (CNC-CliC) was organized to strengthen research on climate and cryosphere in China. Future monitoring of the cryosphere in China will be enhanced both in spatial coverage and through the use of new techniques. Interactions between atmosphere/cryosphere/ hydrosphere/land-surface will be assessed to improve our understanding of the mechanisms of cryospheric change.

Deformation of Tibetan Crust and Mantle and the Uplift of the Plateau: Insights from Broadband Surface Waves

NASA Astrophysics Data System (ADS)

Agius, M. R.; Lebedev, S.

2013-12-01

Seismic deployments over the last two decades have produced dense broadband data coverage across the Tibetan Plateau. Yet, the lithospheric dynamics of Tibet is still debated, with very different end-member models advocated to this day. Uncertainties over the anomalies in seismic tomography models contribute to the uncertainty of their interpretations, ranging from the subduction of India as far as northern Tibet to subduction of Asia there and to extreme viscous thickening of the entire Tibetan lithosphere. Within the lithosphere itself, a low-viscosity layer in the mid-lower crust is evidenced by many observations. It is still unclear, however, whether this layer accommodates a large-scale channel flow (which may have uplifted northern and eastern Tibet, according to one model) or if, instead, deformation within it is similar to that observed at the surface (which implies different uplift mechanisms). Broad-band surface waves provide resolving power from the upper crust down to the asthenosphere, for both isotropic-average shear-wave speeds (proxies for composition and temperature) and the radial and azimuthal shear-wave anisotropy (indicative of the patterns of deformation and flow). We measured highly accurate Love- and Rayleigh-wave phase-velocity curves in broad period ranges (up to 5-200 s) for a few tens of pairs and groups of stations across Tibet, combining, in each case, hundreds to thousands of inter-station measurements, made with cross-correlation and waveform-inversion methods. Robust shear-velocity profiles were then determined by series of non-linear inversions, yielding depth-dependent ranges of shear speeds and radial anisotropy consistent with the data. Temperature anomalies in the upper mantle were estimated from shear-velocity ones using accurate petro-physical relationships. Azimuthal anisotropy in the crust and upper mantle was determined by surface-wave tomography and, also, by sub-array analysis targeting the anisotropy amplitude. Our results show that the prominent high-velocity anomalies in the upper mantle are most consistent with the presence of subducted Indian lithosphere beneath large portions of Tibet. Estimated thermal anomalies within the high-velocity features match those expected for subducted India. The morphology of India's subduction beneath Tibet is complex and shows pronounced west-east variations. Beneath eastern and northeastern Tibet, in particular, the subducted Indian lithosphere appears to have subducted, at a shallow angle, hundreds of km NNE-wards. Azimuthal anisotropy beneath Tibet is distributed in multiple layers with different fast-propagations directions, which accounts for the complexity of published shear-wave splitting observations. The fast directions within the mid-lower crust are parallel to the extensional components of the current strain rate field at the surface, consistent with similar deformation through the entire crust, rather than channel flow. Anisotropy within the asthenosphere beneath northeastern Tibet (sandwiched between the Tibetan lithosphere above and the subducted Indian lithosphere below) indicates SSW-NNE flow, parallel to the direction of motion of the Indian Plate, including its subducted leading edge.

Actinomyces liubingyangii sp. nov. isolated from the vulture Gypaetus barbatus.

PubMed

Meng, Xiangli; Lu, Shan; Lai, Xin-He; Wang, Yiting; Wen, Yumeng; Jin, Dong; Yang, Jing; Xu, Jianguo

2017-06-01

Two strains (VUL4_1T and VUL4_2) of Gram-staining-positive, catalase-negative, non-spore-forming short rods were isolated from rectal swabs of Old World vultures (Gypaetus barbatus) in the Tibet-Qinghai Plateau, China. Analysis of morphological characteristics and biochemical tests indicated that the two strains closely resembled each other but were distinct from other species of the genus Actinomyces previously described. Based on the results of 16S rRNA gene sequence comparison and genome analysis, strains were determined to be members of the genus Actinomyces, closely related to the type strains of Actinomyces marimammalium (96.4 % 16S rRNA gene sequence similarity), Actinomyceshongkongensis (92.4 %), Actinomyceshordeovulneris (92.3 %) and Actinomycesnasicola (92.2 %), respectively. Optimal growth conditions were 37 °C, pH 6-7, with 1 % (w/v) NaCl. Strain VUL4_1T contained C18 : 1ω9c and C16 : 0 as the major cellular fatty acids and diphosphatidylglycerol as the major component of the polar lipids. The genomic DNA G+C content of VUL4_1T was 54.9 mol%. Strain VUL4_1T showed less than 70 % DNA-DNA relatedness with other species of the genus Actinomyces, further supporting strain VUL4_1T as a representative of a novel species. Based on the phenotypic data and phylogenetic inference, a novel species, Actinomyces liubingyangii sp. nov., is proposed with VUL4_1T (=CGMCC 4.7370T=DSM 104050T) as the type strain.

Metataxonomics reveal vultures as a reservoir for Clostridium perfringens.

PubMed

Meng, Xiangli; Lu, Shan; Yang, Jing; Jin, Dong; Wang, Xiaohong; Bai, Xiangning; Wen, Yumeng; Wang, Yiting; Niu, Lina; Ye, Changyun; Rosselló-Móra, Ramon; Xu, Jianguo

2017-02-22

The Old World vulture may carry and spread pathogens for emerging infections since they feed on the carcasses of dead animals and participate in the sky burials of humans, some of whom have died from communicable diseases. Therefore, we studied the precise fecal microbiome of the Old World vulture with metataxonomics, integrating the high-throughput sequencing of almost full-length small subunit ribosomal RNA (16S rRNA) gene amplicons in tandem with the operational phylogenetic unit (OPU) analysis strategy. Nine vultures of three species were sampled using rectal swabs on the Qinghai-Tibet Plateau, China. Using the Pacific Biosciences sequencing platform, we obtained 54 135 high-quality reads of 16S rRNA amplicons with an average of 1442±6.9 bp in length and 6015±1058 reads per vulture. Those sequences were classified into 314 OPUs, including 102 known species, 50 yet to be described species and 161 unknown new lineages of uncultured representatives. Forty-five species have been reported to be responsible for human outbreaks or infections, and 23 yet to be described species belong to genera that include pathogenic species. Only six species were common to all vultures. Clostridium perfringens was the most abundant and present in all vultures, accounting for 30.8% of the total reads. Therefore, using the new technology, we found that vultures are an important reservoir for C. perfringens as evidenced by the isolation of 107 strains encoding for virulence genes, representing 45 sequence types. Our study suggests that the soil-related C. perfringens and other pathogens could have a reservoir in vultures and other animals.

Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015)

PubMed Central

Liang, Junrong; Liang, Yun; Duan, Ran; Tian, Kecheng; Zhao, Yong; Tang, Guangpeng; You, Lv; Yang, Guirong; Liu, Xuebin; Chen, Yuhuang; Zeng, Jun; Wu, Shengrong; Luo, Shoujun; Qin, Gang; Hao, Huijing; Jing, Huaiqi

2017-01-01

Background Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma. Methodology/Principal findings We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years’ surveillance. Conclusions/Significance The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts. PMID:28257423

[Spatial pattern of sub-alpine forest restoration in west Sichuan].

PubMed

Zhang, Yuandong; Liu, Shirong; Zhao, Changming

2005-09-01

West Sichuan sub-alpine is an extension of Qinghai-Tibet Plateau to southeast China, which is covered mainly with dark coniferous forest. As a result of long-term large scale over-logging, the forests have been greatly reduced and degraded. Nowadays, the forest restoration and regeneration in the region are being highlighted. Selecting Miyaluo as a case study area and employing the methods of plot investigation, ETM image interpretation, and overlaying vegetation map with digital topography, this paper analyzed the relations between the appearance and origin of four forest vegetation types, along with their topography differentiation and spatial patterns after a large scale logging and regeneration. The results showed that the appearance of forest vegetations was significantly correlated with their origin. Old coniferous forests (OC) were primitive ones, middle-aged and young coniferous forests (MYC) were from artificial regeneration, deciduous broadleaf forests (DB) were natural secondary ones, while mixed coniferous and deciduous forests (MCD) were partly from natural secondary ones and others from the conjunct action of artificial and natural regeneration. The main cut area in Miyaluo located in the sites with elevation from 2 800 to 3 600 m, where forest restoration appeared difference among different aspects. MYC was mainly distributed on sunny and half-sunny slope, DB and MCD were distributed on shady and half-shady slope, and OC were reserved on the sites with elevation more than 3 600 m. In the process of forest restoration, the four forest vegetation types were in mosaic pattern, and the landscape was seriously fragmentized.

Spatiotemporal characteristics of drought and its impact to vegetation activities in China

NASA Astrophysics Data System (ADS)

Wu, Jianjun; Han, Xinyi; Yang, Jianhua

2017-04-01

Drought is considered as a phenomenon with an imbalance of moisture content payments. As the result of climate change with more prolonged precipitation deficit and abnormal high evaporation, drought is expected to increase in frequency and severity. However, the result from self-calibrating Palmer Drought Severity Index (scPDSI) calculated by different ways showed various performance. Here we show that drought in China experienced a slight increase during the 1948-2012 as the results of monthly 1° scPDSI data sets from J. Sheffield (-0.0295 m-1), the monthly 2.5° scPDSI data sets from Dai (-0.0008 m-1) and the monthly 2.5° scPDSI data sets , from NCAR(-0.0006 m-1), and trends from those different scPDSIs show similar spatial patterns in China. The Central China, Northeast, North China, East China and South China have significant drier trend, while the Southwest and Northwest dry more slightly, because almost half area of this two regions such as Qinghai-Tibet Plateau became wetter in last decades. Meanwhile, the vegetation activities express differently because of vegetation types and dry-wet pattern. Vegetation activities in Northeast experienced a significant decrease (-0.0295 yr-1) between 1992-2005, where the land cover is dominated by wet forests and meadow grasslands. the result investigated by land use and land cover change show that the forest decreased drastically in this region, that maybe caused by the serious trend of drought. Key words: scPDSI, drought, trend, vegetation activity, LUCC

Crustal velocity structure of central Gansu Province from regional seismic waveform inversion using firework algorithm

NASA Astrophysics Data System (ADS)

Chen, Yanyang; Wang, Yanbin; Zhang, Yuansheng

2017-04-01

The firework algorithm (FWA) is a novel swarm intelligence-based method recently proposed for the optimization of multi-parameter, nonlinear functions. Numerical waveform inversion experiments using a synthetic model show that the FWA performs well in both solution quality and efficiency. We apply the FWA in this study to crustal velocity structure inversion using regional seismic waveform data of central Gansu on the northeastern margin of the Qinghai-Tibet plateau. Seismograms recorded from the moment magnitude ( M W) 5.4 Minxian earthquake enable obtaining an average crustal velocity model for this region. We initially carried out a series of FWA robustness tests in regional waveform inversion at the same earthquake and station positions across the study region, inverting two velocity structure models, with and without a low-velocity crustal layer; the accuracy of our average inversion results and their standard deviations reveal the advantages of the FWA for the inversion of regional seismic waveforms. We applied the FWA across our study area using three component waveform data recorded by nine broadband permanent seismic stations with epicentral distances ranging between 146 and 437 km. These inversion results show that the average thickness of the crust in this region is 46.75 km, while thicknesses of the sedimentary layer, and the upper, middle, and lower crust are 3.15, 15.69, 13.08, and 14.83 km, respectively. Results also show that the P-wave velocities of these layers and the upper mantle are 4.47, 6.07, 6.12, 6.87, and 8.18 km/s, respectively.

Metataxonomics reveal vultures as a reservoir for Clostridium perfringens

PubMed Central

Meng, Xiangli; Lu, Shan; Yang, Jing; Jin, Dong; Wang, Xiaohong; Bai, Xiangning; Wen, Yumeng; Wang, Yiting; Niu, Lina; Ye, Changyun; Rosselló-Móra, Ramon; Xu, Jianguo

2017-01-01

The Old World vulture may carry and spread pathogens for emerging infections since they feed on the carcasses of dead animals and participate in the sky burials of humans, some of whom have died from communicable diseases. Therefore, we studied the precise fecal microbiome of the Old World vulture with metataxonomics, integrating the high-throughput sequencing of almost full-length small subunit ribosomal RNA (16S rRNA) gene amplicons in tandem with the operational phylogenetic unit (OPU) analysis strategy. Nine vultures of three species were sampled using rectal swabs on the Qinghai-Tibet Plateau, China. Using the Pacific Biosciences sequencing platform, we obtained 54 135 high-quality reads of 16S rRNA amplicons with an average of 1442±6.9 bp in length and 6015±1058 reads per vulture. Those sequences were classified into 314 OPUs, including 102 known species, 50 yet to be described species and 161 unknown new lineages of uncultured representatives. Forty-five species have been reported to be responsible for human outbreaks or infections, and 23 yet to be described species belong to genera that include pathogenic species. Only six species were common to all vultures. Clostridium perfringens was the most abundant and present in all vultures, accounting for 30.8% of the total reads. Therefore, using the new technology, we found that vultures are an important reservoir for C. perfringens as evidenced by the isolation of 107 strains encoding for virulence genes, representing 45 sequence types. Our study suggests that the soil-related C. perfringens and other pathogens could have a reservoir in vultures and other animals. PMID:28223683

Improving the rainfall rate estimation in the midstream of the Heihe River Basin using rain drop size distribution

NASA Astrophysics Data System (ADS)

Zhao, G.; Chu, R.; Li, X.; Zhang, T.; Shen, J.; Wu, Z.

2009-09-01

During the intensive observation period of the Watershed Allied Telemetry Experimental Research (WATER), a total of 1074 raindrop size distribution were measured by the Parsivel disdrometer, a latest state of the art optical laser instrument. Because of the limited observation data in Qinghai-Tibet Plateau, the modeling behavior was not well-done. We used raindrop size distributions to improve the rain rate estimator of meteorological radar, in order to obtain many accurate rain rate data in this area. We got the relationship between the terminal velocity of the rain drop and the diameter (mm) of a rain drop: v(D)=4.67 D0.53. Then four types of estimators for X-band polarimetric radar are examined. The simulation results show that the classical estimator R(Z) is most sensitive to variations in DSD and the estimator R (KDP, Z, ZDR) is the best estimator for estimating the rain rate. The lowest sensitivity of the rain rate estimator R (KDP, Z, ZDP) to variations in DSD can be explained by the following facts. The difference in the forward-scattering amplitudes at horizontal and vertical polarizations, which contributes KDP, is proportional to the 3rd power of the drop diameter. On the other hand, the exponent of the backscatter cross section, which contributes to Z, is proportional to the 6th power of the drop diameter. Because the rain rate R is proportional to the 3.57th power of the drop diameter, KDP is less sensitive to DSD variations than Z.

Improving the rainfall rate estimation in the midstream of the Heihe River Basin using raindrop size distribution

NASA Astrophysics Data System (ADS)

Zhao, G.; Chu, R.; Zhang, T.; Li, J.; Shen, J.; Wu, Z.

2011-03-01

During the intensive observation period of the Watershed Allied Telemetry Experimental Research (WATER), a total of 1074 raindrop size distribution were measured by the Parsivel disdrometer, the latest state-of-the-art optical laser instrument. Because of the limited observation data in Qinghai-Tibet Plateau, the modelling behaviour was not well done. We used raindrop size distributions to improve the rain rate estimator of meteorological radar in order to obtain many accurate rain rate data in this area. We got the relationship between the terminal velocity of the raindrop and the diameter (mm) of a raindrop: v(D) = 4.67D0.53. Then four types of estimators for X-band polarimetric radar are examined. The simulation results show that the classical estimator R (ZH) is most sensitive to variations in DSD and the estimator R (KDP, ZH, ZDR) is the best estimator for estimating the rain rate. An X-band polarimetric radar (714XDP) is used for verifying these estimators. The lowest sensitivity of the rain rate estimator R (KDP, ZH, ZDR) to variations in DSD can be explained by the following facts. The difference in the forward-scattering amplitudes at horizontal and vertical polarizations, which contributes KDP, is proportional to the 3rd power of the drop diameter. On the other hand, the exponent of the backscatter cross-section, which contributes to ZH, is proportional to the 6th power of the drop diameter. Because the rain rate R is proportional to the 3.57th power of the drop diameter, KDP is less sensitive to DSD variations than ZH.

Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015).

PubMed

Wang, Xin; Wei, Xiaoyu; Song, Zhizhong; Wang, Mingliu; Xi, Jinxiao; Liang, Junrong; Liang, Yun; Duan, Ran; Tian, Kecheng; Zhao, Yong; Tang, Guangpeng; You, Lv; Yang, Guirong; Liu, Xuebin; Chen, Yuhuang; Zeng, Jun; Wu, Shengrong; Luo, Shoujun; Qin, Gang; Hao, Huijing; Jing, Huaiqi

2017-03-01

Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma. We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years' surveillance. The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts.

Streptococcus himalayensis sp. nov., isolated from the respiratory tract of Marmota himalayana.

PubMed

Niu, Lina; Lu, Shan; Lai, Xin-He; Hu, Shoukui; Chen, Cuixia; Zhang, Gui; Yang, Jing; Jin, Dong; Wang, Yi; Lan, Ruiting; Lu, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

2017-02-01

Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995T (98.4 % similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2T and Streptococcus. marmotae DSM 101995T, its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2T forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2T showed an estimated DNA reassociation value of 40.5 % with Streptococcus. marmotae DSM 101995T. On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2T (=DSM 101997T=CGMCC 1.15533T). The genome of Streptococcus himalayensis sp. nov. strain HTS2T contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.

Viviparity in high-altitude Phrynocephalus lizards is adaptive because embryos cannot fully develop without maternal thermoregulation.

PubMed

Wang, Zheng; Lu, Hong-Liang; Ma, Li; Ji, Xiang

2014-03-01

Viviparous Phrynocephalus lizards (Agamidae) are mainly restricted to the Qinghai-Tibet Plateau of China. In this study, we used Phrynocephalus vlangalii females kept under seven thermal regimes for the whole gestation period to test the hypothesis that viviparity in high-altitude Phrynocephalus lizards is adaptive because embryos cannot fully develop without maternal thermoregulation. All females at 24 °C and 93% of the females at 28 °C failed to give birth or produced stillborns, and proportionally fewer females gave birth at 29 or 35 °C than at 32 °C. Though the daily temperatures encountered were unsuitable for embryonic development, 95% of the females in nature and 89% of the females thermoregulating in the laboratory gave birth. There was no shift in the thermal preferences of females when they were pregnant. Although thermal conditions inside natural burrows were unsuitable for embryonic development, mass and sprint speed were both greater in neonates produced in nature. Our data show that (1) long-term exposure of P. vlangalii embryos to temperatures outside the range of 29-35 °C may result in the failure of development, but daily or short-term exposure may not necessarily increase embryonic mortality; (2) low gestation temperatures slow but do not arrest embryonic development, and females produce high-quality offspring in the shortest possible time by maintaining gestation temperatures close to the upper thermal limit for embryonic development; and (3) viviparity is currently adaptive at high elevations because embryos in nature cannot fully develop without relying on maternal thermoregulation. Our data validate the hypothesis tested.

Impacts of altitude and position on the rates of soil nitrogen mineralization and nitrification in alpine meadows on the eastern Qinghai-Tibetan Plateau, China

USDA-ARS?s Scientific Manuscript database

Alpine and tundra grasslands constitute 7% world terrestrial land but 13% of the total global soil carbon (C) and 10% of the global soil nitrogen (N). Under the current climate change scenario of global warming, these grasslands will contribute significantly to the changing global C and N cycles. It...

Study of the Qinghai-Tibetan Plateau Permafrost Active Layer Thickening Rate Using ALOS-1/-2 Interferometric SAR Data

NASA Astrophysics Data System (ADS)

Jia, Y.; Shum, C. K.; Kim, J.; Lu, Z.; Kuo, C. Y.; Zhang, L.; Ding, X.

2016-12-01

The Qinghai-Tibetan Plateau(QTP) is the world's largest and the highest plateau with distinct and competing surface and subsurface processes. It is the Third Pole and the World Water Tower, owing to its vast ice reservoir with the largest number of glaciers in the world. The QTP is covered by a large (1.3 to 1.6 million km2) layer of discontinuous and sporadic alpine permafrost, and is the origin of the largest rivers across Asia, feeding water to billions of people downstream. One such origin is the Three-River Headwater System, comprising of the mighty Yangtze, Yellow, and Lancang/Mekong Rivers, a subject of this study. The thawing over QTP permafrost regions is thought to be more severe compared with other high latitude permafrost regions by the fact that most of the permafrost is warm. During the past few decades, 10% permafrost has degraded. The overall mean active layer (AL) thickening rates over the QTP from model studies were 1.4 cm yr-1 during 1980-2001 and approximately 6.3 cm yr-1 during 2006-2010, based on soil temperature profiles for 27 monitoring sites along Qinghai-Tibetan railway (QTR). Here we report on a study on quantifying AL thickening rate in the northern QTP along the QTR, using ALOS-1/-2 InSAR observed land subsidence and AL thickness modeling. We have characterized high spatial resolution (30 m) and spatially varying ALT thickening rates, 2007-2010, along the QTR's large permafrost areas (> 10,000 km2). InSAR measured subsidence rates over various thermokarst surfaces in the study region are then converted to AL thickening rates using models with estimates ranging from 2.0 cm yr-1 to 10.7 cm yr-1. Comparisons with five borehole in situ sites showed excellent agreements with r2 >0.9. Using the ALOS-1/-2 InSAR data, we have further studied the plausible contribution of permafrost in NE QTP to the Yangtze headwater runoff near the Tuotuo river.

Continental deformation accommodated by non-rigid passive bookshelf faulting: An example from the Cenozoic tectonic development of northern Tibet

NASA Astrophysics Data System (ADS)

Zuza, Andrew V.; Yin, An

2016-05-01

Collision-induced continental deformation commonly involves complex interactions between strike-slip faulting and off-fault deformation, yet this relationship has rarely been quantified. In northern Tibet, Cenozoic deformation is expressed by the development of the > 1000-km-long east-striking left-slip Kunlun, Qinling, and Haiyuan faults. Each have a maximum slip in the central fault segment exceeding 10s to ~ 100 km but a much smaller slip magnitude (~< 10% of the maximum slip) at their terminations. The along-strike variation of fault offsets and pervasive off-fault deformation create a strain pattern that departs from the expectations of the classic plate-like rigid-body motion and flow-like distributed deformation end-member models for continental tectonics. Here we propose a non-rigid bookshelf-fault model for the Cenozoic tectonic development of northern Tibet. Our model, quantitatively relating discrete left-slip faulting to distributed off-fault deformation during regional clockwise rotation, explains several puzzling features, including the: (1) clockwise rotation of east-striking left-slip faults against the northeast-striking left-slip Altyn Tagh fault along the northwestern margin of the Tibetan Plateau, (2) alternating fault-parallel extension and shortening in the off-fault regions, and (3) eastward-tapering map-view geometries of the Qimen Tagh, Qaidam, and Qilian Shan thrust belts that link with the three major left-slip faults in northern Tibet. We refer to this specific non-rigid bookshelf-fault system as a passive bookshelf-fault system because the rotating bookshelf panels are detached from the rigid bounding domains. As a consequence, the wallrock of the strike-slip faults deforms to accommodate both the clockwise rotation of the left-slip faults and off-fault strain that arises at the fault ends. An important implication of our model is that the style and magnitude of Cenozoic deformation in northern Tibet vary considerably in the east-west direction. Thus, any single north-south cross section and its kinematic reconstruction through the region do not properly quantify the complex deformational processes of plateau formation.

Compressional Wave Q in the Uppermost Mantle Beneath the Tibetan Plateau Measured Using Pn Wave Spectra

NASA Astrophysics Data System (ADS)

Xie, J.

2003-12-01

Pn waves from three near-colocated seismic events in the eastern Tarim Basin are well-recorded by the INDEPTH III and II arrays, which are deployed from northern to southern Tibet with a small east-west spread (between ˜88 and 91° E). The paths run southward and sample the Tibetan mantle with epicentral distances increasing from 870 to 1540 km. These waves have spectral contents that are distinctly different from those collected from the Kyrghistan network (KNET), to which the paths traverse westward through the eastern Tienshan. Pn Q beneath Tibet and Tienshan must therefore be different. Xie and Patton (1999,JGR, 104, 941-954) have simultaneously estimated source spectra of the co-located events, and path-averaged Pn Q to the KNET stations. Under a simplified geometrical spreading of Δ -1.3, they have estimated Q0 and η (Pn Q at 1 Hz and its frequency dependence) to KNET to be about 360 and 0.5, respectively. Using those estimates as a priori knowledge, we estimate that Q0 and η are ~180 and 0.3 along paths to northern Tibet, and ˜260 and 0.0 along paths to southern Tibet. The southward increase of Q0 correlates well with a similar increase in Pn velocity contained in previous tomographic images. Additionally, we measured Pn Q using a two-station method along two profiles (from station SANG to TUNL, and GANZ to MAQI) deployed during the 1991-1992 Sino-US Tibetan Plateau experiment. Both profiles are located to the east of 92° E. Along profile SANG-TUNL, we estimate Q0 and η to be ˜270 and 0.0, respectively. The Q0 value is rather high, but correlates well with the high Pn velocities of > 8.1 km/s re-measured in this study. Our results suggest that the zone of low Pn Q0 and velocity in northern Tibet, which is likely caused by high mantle temperature and partial melting, is confined to the west of 92° E. This is so despite that the zone of high Sn attenuation extends to further east.

Summer Dust Aerosols Detected from CALIPSO Observations over the Tibetan Plateau

NASA Technical Reports Server (NTRS)

Huang, Jianping; Minnis, Patrick; Yi, Yuhong; Tang, Qiang; Wang, Xin; Hu, Yongxiang; Liu, Zhaoyan; Ayers, Kirk; Trepte, Charles; Winker, David

2007-01-01

Summertime Tibetan dust aerosol plumes are detected from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. CALIPSO reveals that dust storms occur 4 times more frequently than previously found from Tibetan surface observations because few surface sites were available over remote northwestern Tibet. The Tibetan dust aerosol is characterized by column-averaged depolarization and color ratios around 21% and 0.83, respectively. The dust layers appear most frequently around 4-7 km above mean sea level. The depolarization ratio for about 90% of the dust particles is less than 10% at low altitudes (3-5 km), while only about 50% of the particles have a greater depolarization ratio at higher altitudes (7-10 km) suggesting a separation of larger irregular particles from smaller, near spherical ones during transport. The 4-day back trajectory analyses show that these plumes probably originate from the nearby Taklimakan desert surface and accumulate over the northern slopes of the Tibetan Plateau. These dust outbreaks can affect the radiation balance of the atmosphere of Tibet because they both absorb and reflect solar radiation.

The influence of climatic changes on distribution pattern of six typical Kobresia species in Tibetan Plateau based on MaxEnt model and geographic information system

NASA Astrophysics Data System (ADS)

Hu, Zhongjun; Guo, Ke; Jin, Shulan; Pan, Huahua

2018-01-01

The issue that climatic change has great influence on species distribution is currently of great interest in field of biogeography. Six typical Kobresia species are selected from alpine grassland of Tibetan Plateau (TP) as research objects which are the high-quality forage for local husbandry, and their distribution changes are modeled in four periods by using MaxEnt model and GIS technology. The modeling results have shown that the distribution of these six typical Kobresia species in TP was strongly affected by two factors of "the annual precipitation" and "the precipitation in the wettest and driest quarters of the year". The modeling results have also shown that the most suitable habitats of K. pygmeae were located in the area around Qinghai Lake, the Hengduan-Himalayan mountain area, and the hinterland of TP. The most suitable habitats of K. humilis were mainly located in the area around Qinghai Lake and the hinterland of TP during the Last Interglacial period, and gradually merged into a bigger area; K. robusta and K. tibetica were located in the area around Qinghai Lake and the hinterland of TP, but they did not integrate into one area all the time, and K. capillifolia were located in the area around Qinghai Lake and extended to the southwest of the original distributing area, whereas K. macrantha were mainly distributed along the area of the Himalayan mountain chain, which had the smallest distribution area among them, and all these six Kobresia species can be divided into four types of "retreat/expansion" styles according to the changes of suitable habitat areas during the four periods; all these change styles are the result of long-term adaptations of the different species to the local climate changes in regions of TP and show the complexity of relationships between different species and climate. The research results have positive reference value to the protection of species diversity and sustainable development of the local husbandry in TP.

A Comparative Study of the Electrical Structure of Circum Tibetan Plateau Orogenic Belts and its Tectonic Implications

NASA Astrophysics Data System (ADS)

Jin, Sheng; Zhang, Letian; Wei, Wenbo; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

2017-04-01

The Tibetan Plateau, as known as "roof of the world", was created through the on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma. As the process continues, the plateau is growing both vertically and horizontally. The horizontal expansion of the plateau is blocked by the Yangtze block in the east, the Tarim block in the north, and the Ordos block in the northeast, and consequently lead to the formation of the circum Tibetan plateau orogenic belts. To better understand the mechanism behind this process, we conducted a comparative study by collecting 7 magnetotelluric (MT) profiles over the margins of the Tibetan plateau, namely, the INDEPTH 100, 700 and 800 lines in the southern Tibet, the INDEPTH 4000 and 5000 lines across the Altyn Tagh fault on the northern margin of the plateau, as well as other two profiles across the Haiyuan fault and the Longmenshan fault on the northeastern and eastern margins of the plateau deployed under the framework of project SinoProbe. The electrical features of the stable blocks surrounding the Tibetan plateau are generally resistive, while crustal conductive layers are found to be wide spread within the plateau. The southern margin of the Tibetan plateau is characterized by large scale underthrust of the Indian lithosphere beneath the plateau. This intense converging process created the thrust fault system distributed along the southern margin of the Tibetan plateau over 1000 km. Crustal conductive layers discovered in southern Tibet are generally associated with the southward crustal flow that originated from the lower crust within the plateau and exhumed along the thrust belts in the Himalayas. On the eastern margin of the Tibetan plateau, the electrical structures suggest that the Yangtze block wedged into the Tibetan lithosphere and caused decoupling between the crust and upper mantel. Large scale conductors discovered beneath the Songpan-Ganze block reflect that the eastward crustal flow was blocked and piled up along the eastern margin of the plateau due to the block of the Sichuan Basin, which further result in the uplift and expansion of the eastern Tibetan plateau. The northeastern and northern margins of the Tibetan plateau is bounded by large scale left-lateral strike-slip Haiyuan and Altyn Tagh faults. In these regions, the plateau interacts with the surrounding stable blocks in a way of oblique strike-slip. The deformation of the northern Tibetan lithosphere is dominated by crustal thickening, where no features of decoupling or large scale underthrusting were seen. Crustal conductors in these regions are generally not very well connected, which suggest the absence of crustal flow. Deep metamorphism fluids could be an alternative interpretation of the crustal conductors in these regions. * This work was jointly supported by the grants from Project SinoProbe-02-04 and National Natural Science Foundation of China (41404060).

Assessment of Satellite Surface Radiation Products in Highland Regions with Tibet Instrumental Data

NASA Technical Reports Server (NTRS)

Yang, Kun; Koike, Toshio; Stackhouse, Paul; Mikovitz, Colleen

2006-01-01

This study presents results of comparisons between instrumental radiation data in the elevated Tibetan Plateau and two global satellite products: the Global Energy and Water Cycle Experiment - Surface Radiation Budget (GEWEX-SRB) and International Satellite Cloud Climatology Project - Flux Data (ISCCP-FD). In general, shortwave radiation (SW) is estimated better by ISCCP-FD while longwave radiation (LW) is estimated better by GEWEX-SRB, but all the radiation components in both products are under-estimated. Severe and systematic errors were found in monthly-mean SRB SW (on plateau-average, -48 W/sq m for downward SW and -18 W/sq m for upward SW) and FD LW (on plateau-average, -37 W/sq m for downward LW and -62 W/sq m for upward LW) for radiation. Errors in monthly-mean diurnal variations are even larger than the monthly mean errors. Though the LW errors can be reduced about 10 W/sq m after a correction for altitude difference between the site and SRB and FD grids, these errors are still higher than that for other regions. The large errors in SRB SW was mainly due to a processing mistake for elevation effect, but the errors in SRB LW was mainly due to significant errors in input data. We suggest reprocessing satellite surface radiation budget data, at least for highland areas like Tibet.

[Hydrogen and oxygen isotopes of lake water and geothermal spring water in arid area of south Tibet].

PubMed

Xiao, Ke; Shen, Li-Cheng; Wang, Peng

2014-08-01

The condition of water cycles in Tibet Plateau is a complex process, and the hydrogen and oxygen isotopes contain important information of this process. Based on the analysis of isotopic composition of freshwater lake, saltwater lake and geothermal water in the southern Tibetan Plateau, this study investigated water cycling, composition and variation of hydrogen and oxygen isotopes and the influencing factors in the study area. The study found that the mean values of delta18O and deltaD in Daggyaima lake water (-17.0 per thousand for delta18O and -138. 6 per thousand for deltaD), Langcuo lake water (-6.4 per thousand for delta18O and -87.4 per thousand for deltaD) and Dagejia geothermal water (-19.2 per thousand for delta18 and -158.2 per thousand for deltaD) all showed negative delta18O and deltaD values in Tibetan Plateau by the influence of altitude effects. Lake water and geothermal water were influenced by evaporation effects in inland arid area, and the slope of evaporation line was less than 8. Deuterium excess parameters of lake water and geothermal water were all negative. The temperature of geothermal reservoirs in Dagejia geothermal field was high,and oxygen shift existed in the relationship of hydrogen and oxygen isotopes.

Paleoenvironmental reconstruction of a saline lake in the Tertiary: Evidence from aragonite laminae in the northern Tibet Plateau

NASA Astrophysics Data System (ADS)

Ma, Jian; Wu, Chaodong; Wang, Yizhe; Wang, Jialin; Fang, Yanan; Zhu, Wen; Zhai, Lina; Zhou, Tianqi

2017-05-01

The origin of aragonite has long been debated because it is precipitated and preserved under specific conditions. Aragonite laminae, first found from Eocene to Miocene strata in the western Qaidam Basin, northern Tibet Plateau, contain much information on paleolake signatures. Mineralogical and geochemical analyses were conducted on alternating yellowish and grayish aragonite layers. The yellowish layers are mainly composed of aragonite crystals, while the grayish layers contain less aragonite and fewer organic remnants that accumulate among debris with sporadic framboidal pyrite. The δ13C values of yellowish layers are remarkably positive by approximately 4.01‰ (VPDB), and the δ18O values are slightly negative compared with base data of the Qaidam Basin. Considering the 12CO2 absorption of algal blooms, positive excursions of δ13C shown in aragonite indicate high 13C values in depositional water. Therefore, a seasonal algal-influenced inorganic origin is proposed to explain the formation of aragonite laminae. During warm seasons, Mg/Ca ratios are elevated because of evaporation effects. The algal blooms decrease the CO2 content, leading to high pH values. These conditions promote the rapid crystal growth of aragonite instead of other carbonate minerals. Slightly negative δ18O values in yellowish layers are interpreted as the result of intense inflow during warm seasons, which leads to less precipitation of organic matter and debris. The grayish layers in cold seasons are the opposite. From the Eocene to Oligocene, the progressively decreasing δ18O values of aragonite reflect global cooling during this time. A conspicuously positive step in δ18O values indicates an arid environment coinciding with the uplift of the Himalaya, from the Oligocene to Lower Miocene. The results from this study show that understanding of aragonite in the Qaidam Basin is essential to reconstruct the high-resolution paleoenvironment and to reveal the Tertiary evolution of paleoclimates in the northern Tibet Plateau.

Genetic diversity and population structure of Prunus mira (Koehne) from the Tibet plateau in China and recommended conservation strategies

PubMed Central

Bao, Wenquan; Li, Tiezhu; Liu, Huimin; Jiang, Zhongmao; Zhu, Xuchun; Du, Hongyan; Bai, Yu-e

2017-01-01

Prunus mira Koehne, an important economic fruit crop with high breeding and medicinal values, and an ancestral species of many cultivated peach species, has recently been declared an endangered species. However, basic information about genetic diversity, population structure, and morphological variation is still limited for this species. In this study, we sampled 420 P. mira individuals from 21 wild populations in the Tibet plateau to conduct a comprehensive analysis of genetic and morphological characteristics. The results of molecular analyses based on simple sequence repeat (SSR) markers indicated moderate genetic diversity and inbreeding (A = 3.8, Ae = 2.5, He = 0.52, Ho = 0.44, I = 0.95, FIS = 0.17) within P. mira populations. STRUCTURE, GENELAND, and phylogenetic analyses assigned the 21 populations to three genetic clusters that were moderately correlated with geographic altitudes, and this may have resulted from significantly different climatic and environmental factors at different altitudinal ranges. Significant isolation-by-distance was detected across the entire distribution of P. mira populations, but geographic altitude might have more significant effects on genetic structure than geographic distance in partial small-scale areas. Furthermore, clear genetic structure, high genetic differentiation, and restricted gene flow were detected between pairwise populations from different geographic groups, indicating that geographic barriers and genetic drift have significant effects on P. mira populations. Analyses of molecular variance based on the SSR markers indicated high variation (83.7% and 81.7%), whereas morphological analyses revealed low variation (1.30%–36.17%) within the populations. Large and heavy fruits were better adapted than light fruits and nutlets to poor climate and environmental conditions at high altitudes. Based on the results of molecular and morphological analyses, we classified the area into three conservation units and proposed several conservation strategies for wild P. mira populations in the Tibet plateau. PMID:29186199

Genetic diversity and population structure of Prunus mira (Koehne) from the Tibet plateau in China and recommended conservation strategies.

PubMed

Bao, Wenquan; Wuyun, Tana; Li, Tiezhu; Liu, Huimin; Jiang, Zhongmao; Zhu, Xuchun; Du, Hongyan; Bai, Yu-E

2017-01-01

Prunus mira Koehne, an important economic fruit crop with high breeding and medicinal values, and an ancestral species of many cultivated peach species, has recently been declared an endangered species. However, basic information about genetic diversity, population structure, and morphological variation is still limited for this species. In this study, we sampled 420 P. mira individuals from 21 wild populations in the Tibet plateau to conduct a comprehensive analysis of genetic and morphological characteristics. The results of molecular analyses based on simple sequence repeat (SSR) markers indicated moderate genetic diversity and inbreeding (A = 3.8, Ae = 2.5, He = 0.52, Ho = 0.44, I = 0.95, FIS = 0.17) within P. mira populations. STRUCTURE, GENELAND, and phylogenetic analyses assigned the 21 populations to three genetic clusters that were moderately correlated with geographic altitudes, and this may have resulted from significantly different climatic and environmental factors at different altitudinal ranges. Significant isolation-by-distance was detected across the entire distribution of P. mira populations, but geographic altitude might have more significant effects on genetic structure than geographic distance in partial small-scale areas. Furthermore, clear genetic structure, high genetic differentiation, and restricted gene flow were detected between pairwise populations from different geographic groups, indicating that geographic barriers and genetic drift have significant effects on P. mira populations. Analyses of molecular variance based on the SSR markers indicated high variation (83.7% and 81.7%), whereas morphological analyses revealed low variation (1.30%-36.17%) within the populations. Large and heavy fruits were better adapted than light fruits and nutlets to poor climate and environmental conditions at high altitudes. Based on the results of molecular and morphological analyses, we classified the area into three conservation units and proposed several conservation strategies for wild P. mira populations in the Tibet plateau.

Measuring Surface Deformation in Glacier Retreated Areas Based on Ps-Insar - Geladandong Glacier as a Case Study

NASA Astrophysics Data System (ADS)

Mohamadi, B.; Balz, T.

2018-04-01

Glaciers are retreating in many parts of the world as a result of global warming. Many researchers consider Qinghai-Tibetan Plateau as a reference for climate change by measuring glaciers retreat on the plateau. This retreat resulted in some topographic changes in retreated areas, and in some cases can lead to geohazards as landslides, and rock avalanches, which is known in glacier retreated areas as paraglacial slope failure (PSF). In this study, Geladandong biggest and main glacier mass was selected to estimate surface deformation on its glacier retreated areas and define potential future PSF based on PS-InSAR technique. 56 ascending and 49 descending images were used to fulfill this aim. Geladandong glacier retreated areas were defined based on the maximum extent of the glacier in the little ice age. Results revealed a general uplift in the glacier retreated areas with velocity less than 5mm/year. Obvious surface motion was revealed in seven parts surround glacier retreated areas with high relative velocity reached ±60mm/year in some parts. Four parts were considered as PSF potential motion, and two of them showed potential damage for the main road in the study area in case of rock avalanche into recent glacier lakes that could result in glacier lake outburst flooding heading directly to the road. Finally, further analysis and field investigations are needed to define the main reasons for different types of deformation and estimate future risks of these types of surface motion in the Qinghai-Tibetan Plateau.

Genetic structure and demographic history of the endangered and endemic schizothoracine fish Gymnodiptychus pachycheilus in Qinghai-Tibetan Plateau.

PubMed

Su, Junhu; Ji, Weihong; Wei, Yanming; Zhang, Yanping; Gleeson, Dianne M; Lou, Zhongyu; Ren, Jing

2014-08-01

The endangered schizothoracine fish Gymnodiptychus pachycheilus is endemic to the Qinghai-Tibetan Plateau (QTP), but very little genetic information is available for this species. Here, we accessed the current genetic divergence of G. pachycheilus population to evaluate their distributions modulated by contemporary and historical processes. Population structure and demographic history were assessed by analyzing 1811-base pairs of mitochondrial DNA from 61 individuals across a large proportion of its geographic range. Our results revealed low nucleotide diversity, suggesting severe historical bottleneck events. Analyses of molecular variance and the conventional population statistic FST (0.0435, P = 0.0215) confirmed weak genetic structure. The monophyly of G. pachycheilus was statistically well-supported, while two divergent evolutionary clusters were identified by phylogenetic analyses, suggesting a microgeographic population structure. The consistent scenario of recent population expansion of two clusters was identified based on several complementary analyses of demographic history (0.096 Ma and 0.15 Ma). This genetic divergence and evolutionary process are likely to have resulted from a series of drainage arrangements triggered by the historical tectonic events of the region. The results obtained here provide the first insights into the evolutionary history and genetic status of this little-known fish.

Emergence of ancient cities in relation to geopolitical circumstances and climate change during late Holocene in northeastern Tibetan Plateau, China

NASA Astrophysics Data System (ADS)

Dong, Guanghui; Liu, Honggao; Yang, Yishi; Yang, Ying; Zhou, Aifeng; Wang, Zhongxin; Ren, Xiaoyan; Chen, Fahu

2016-12-01

The study of the history of human activities in ancient cities has provided valuable evidences for understanding the evolution of human-land relations during the late Holocene. Numerous ancient cities were discovered through archaeological surveys of the east Qinghai Province, located on the northeastern border of the Tibetan Plateau, China; however, the mystery of when or why these cities were built remains unsolved. As recorded in this paper, we sampled reliable dating materials from 47 ancient cities in the area, determined their ages by radiocarbon dating, and compared the dating results with historical documents and high resolution paleoclimate records to explore the influencing factors for the development of these ancient cities. The 54 radiocarbon dates indicated that most of these cities were built or repaired during the Han Dynasty (202 BC‒AD 220), Tang Dynasty (AD 618‒AD 907), the Five Dynasties and Ten Kingdoms period (AD 907‒AD 960), the Song dynasty (AD 960‒AD 1279), and the Ming Dynasty (AD 1368‒AD 1644). The radiocarbon dates correspond well with historical records of the area. Our work suggests the ancient cities in east Qinghai Province were likely built primarily for military defense, and may have also have been affected by climate change.

Evolutionary diversifications of plants on the Qinghai-Tibetan Plateau

PubMed Central

Wen, Jun; Zhang, Jian-Qiang; Nie, Ze-Long; Zhong, Yang; Sun, Hang

2014-01-01

The Qinghai-Tibetan Plateau (QTP) is the highest and one of the most extensive plateaus in the world. Phylogenetic, phylogeographic, and ecological studies support plant diversifications on the QTP through multiple mechanisms such as allopatric speciation via geographic isolation, climatic oscillations and divergences, pollinator-mediated isolation, diploid hybridization and introgression, and allopolyploidy. These mechanisms have driven spectacular radiations and/or species diversifications in various groups of plants such as Pedicularis L., Saussurea DC., Rhododendron L., Primula L., Meconopsis Vig., Rhodiola L., and many lineages of gymnosperms. Nevertheless, much work is needed toward understanding the evolutionary mechanisms of plant diversifications on the QTP. Well-sampled biogeographic analyses of the QTP plants in the broad framework of the Northern Hemisphere as well as the Southern Hemisphere are still relatively few and should be encouraged in the next decade. This paper reviews recent evidence from phylogenetic and biogeographic studies in plants, in the context of rapid radiations, mechanisms of species diversifications on the QTP, and the biogeographic significance of the QTP in the broader context of both the Northern and Southern Hemisphere biogeography. Integrative multidimensional analyses of phylogeny, morphological innovations, geography, ecology, development, species interactions and diversifications, and geology are needed and should shed insights into the patterns of evolutionary assembly and radiations in this fascinating region. PMID:24575120

Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment

PubMed Central

Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian

2015-01-01

Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records. PMID:26449321

Linking Late Miocene Magmatism and Exhumation of the Pamir-West Kunlun Mountains to Lithospheric Thinning

NASA Astrophysics Data System (ADS)

Cao, K.; Wang, G.; Zeng, Z.; Replumaz, A.

2016-12-01

In this study, we report newly-discovered potassic plutons emplaced at 11 Ma in the SE Pamir. Together with recently-reported volcanism at 12 Ma in the West Kunlun Mts. (Cao et al., 2015), it can be inferred that Late Miocene magmas extend from the north-central Tibet to the central Pamir. Furthermore, our new apatite fission-track analysis in the SE Pamir-West Kunlun Mountains present uniform ages clustering at 11-6 Ma. Forward and inverse modeling indicate Late Miocene ( 11-6 Ma) rapid exhumation of the SE Pamir-West Kunlun Mountains, concurrent with accelerated exhumation of the Shakhdara dome (Stübner et al., 2013), initial doming of the Muztagata massif (Robinson et al., 2007; Sobel et al., 2011; Cao et al., 2013), and thrusting of the front faults along Pamir-West Kunlun Mts. (Bershaw et al., 2012; Cao et al., 2013, 2015). The simultaneous doming and potassic magmatism could attributed to stress relaxation of the upper crust at that time, possibly driven by the thinning of lower lithosphere beneath Pamir-West Kunlun Mts.. Such plausible mechanisms could be responsible for Neogene magmatism, rock exhumation and plateau growth in northwestern Tibet. At the continental scale, our results support that the Tibetan Plateau underwent a Late Miocene phase of deformation and developed outward and upward since then (Molnar et al., 2012). Three representative models are proposed to account for Late Miocene magmatism and crustal deformation in northern Tibet, including 1) southward subduction of the Tarim lithosphere mantle (Matte et al., 1996; Wittlinger et al., 2004), 2) convective removal of lower lithosphere (Molnar et al., 1993; Turner et al., 1993, 1996), and 3) penetration of molten crust into Kunlun terrane (Le Pape et al., 2012; Wang et al., 2012). Our results allow to discuss these competing models in the western Tibet, to better understand the intracontinent orogenesis in central Asia, in which the lithospheric processes have led to upper crust deformation.

Toward Understanding the Genetic Basis of Yak Ovary Reproduction: A Characterization and Comparative Analyses of Estrus Ovary Transcriptiome in Yak and Cattle.

PubMed

Lan, Daoliang; Xiong, Xianrong; Huang, Cai; Mipam, Tserang Donko; Li, Jian

2016-01-01

Yaks (Bos grunniens) are endemic species that can adapt well to thin air, cold temperatures, and high altitude. These species can survive in harsh plateau environments and are major source of animal production for local residents, being an important breed in the Qinghai-Tibet Plateau. However, compared with ordinary cattle that live in the plains, yaks generally have lower fertility. Investigating the basic physiological molecular features of yak ovary and identifying the biological events underlying the differences between the ovaries of yak and plain cattle is necessary to understand the specificity of yak reproduction. Therefore, RNA-seq technology was applied to analyze transcriptome data comparatively between the yak and plain cattle estrous ovaries. After deep sequencing, 3,653,032 clean reads with a total of 4,828,772,880 base pairs were obtained from yak ovary library. Alignment analysis showed that 16992 yak genes mapped to the yak genome, among which, 12,731 and 14,631 genes were assigned to Gene Ontology (GO) categories and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Furthermore, comparison of yak and cattle ovary transcriptome data revealed that 1307 genes were significantly and differentially expressed between the two libraries, wherein 661 genes were upregulated and 646 genes were downregulated in yak ovary. Functional analysis showed that the differentially expressed genes were involved in various Gene Ontology (GO) categories and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. GO annotations indicated that the genes related to "cell adhesion," "hormonal" biological processes, and "calcium ion binding," "cation transmembrane transport" molecular events were significantly active. KEGG pathway analysis showed that the "complement and coagulation cascade" pathway was the most enriched in yak ovary transcriptome data, followed by the "cytochrome P450" related and "ECM-receptor interaction" pathways. Moreover, several novel pathways, such as "circadian rhythm," were significantly enriched despite having no evident associations with the reproductive function. Our findings provide a molecular resource for further investigation of the general molecular mechanism of yak ovary and offer new insights to understand comprehensively the specificity of yak reproduction.

Crustal deformation characteristics of Sichuan-Yunnan region in China on the constraint of multi-periods of GPS velocity fields

NASA Astrophysics Data System (ADS)

Yue, Caiya; Dang, Yamin; Dai, Huayang; Yang, Qiang; Wang, Xiankai

2018-04-01

In order to obtain deformation parameters in each block of Sichuan-Yunnan Region (SYG) in China by stages and establish a dynamic model about the variation of the strain rate fields and the surface expansion in this area, we taken the Global Positioning System (GPS) sites velocity in the region as constrained condition and taken advantage of the block strain calculation model based on spherical surface. We also analyzed the deformation of the active blocks in the whole SYG before and after the Wenchuan earthquake, and analyzed the deformation of active blocks near the epicenter of the Wenchuan earthquake in detail. The results show that, (1) Under the effects of the carving from India plate and the crimping from the potential energy of Tibetan Plateau for a long time, there is a certain periodicity in crustal deformation in SYG. And the period change and the earthquake occurrence have a good agreement. (2) The differences in GPS velocity fields relative Eurasian reference frame shows that the Wenchuan earthquake and the Ya'an earthquake mainly affect the crustal movement in the central and southern part of SYG, and the average velocity difference is about 4-8 mm/a for the Wenchuan earthquake and 2-4 mm/a for the Ya'an earthquake. (3) For the Wenchuan earthquake, the average strain changed from 10 to 20 nanostrian/a before earthquake to 40-50 nanostrian/a after the earthquake, but before and after the Ya'an earthquake, the strain value increased from about 15 nanostrian/a to about 30 nanostrian/a. (4) The Wenchuan earthquake has changed the strain parameter of each active block more or less. Especially, the Longmen block and Chengdu block near the epicenter. The research provides fundamental material for the study of the dynamic mechanism of the push extrusion from the north-east of the India plate and the crimp from Qinghai Tibet Plateau, and it also provides support for the study of crustal stress variation and earthquake prediction in Sichuan Yunnan region.

The protein level of hypoxia-inducible factor-1alpha is increased in the plateau pika (Ochotona curzoniae) inhabiting high altitudes.

PubMed

Li, Hong-Ge; Ren, Yong-Ming; Guo, Song-Chang; Cheng, Long; Wang, De-Peng; Yang, Jie; Chang, Zhi-Jie; Zhao, Xin-Quan

2009-02-01

The plateau pika (Ochotona curzoniae) is a high hypoxia-tolerant species living only at 3,000-5,000 m above sea-level on the Qinghai-Tibetan plateau. Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor that regulates a variety of cellular and systemic adaptations to hypoxia. To investigate how the plateau pika adapts to a high-altitude hypoxic environment at the molecular level, we examined the expression pattern of the HIF-1alpha protein in the pika by Western blot and immunohistochemical analysis. We found that HIF-1alpha protein is expressed at a significantly high level in the pika, which is higher in most tissues (particularly in the lung, liver, spleen and kidney) of the plateau pika than that of mice living at sea-level. Importantly, we found that the protein levels of HIF-1alpha in the lung, liver, spleen and kidney of the pika were increased with increased habitat altitudes. We observed that the plateau pika HIF-1alpha localized to the nucleus of cells by an immunostaining analysis, and enhanced HRE-driven gene expression by luciferase reporter assays. Our study suggests that the HIF-1alpha protein levels are related to the adaptation of the plateau pika to the high-altitude hypoxic environment.

Study of the Northern Qinghai-Tibetan Plateau Permafrost Active Layer Depth Rate Using Satellite Geodetic Observations

NASA Astrophysics Data System (ADS)

Jia, Y.; Su, X.; Shum, C. K.; Kim, J. W.; Kuo, C. Y.

2015-12-01

The Tibetan Plateau is the world's largest and the highest plateau with distinct and competing surface and subsurface processes. It is the Third Pole and the World Water Tower, owing to its vast ice reservoir with the largest number of glaciers in the world, and covered by a large (1.3 to 1.6 million km2) layer of discontinuous and sporadic alpine permafrost. The thawing over Tibetan Plateau permafrost regions is thought to be more severe compared with other high latitude permafrost regions by the fact that the permafrost is warm. During the past few decades, 82% of Tibetan Plateau glaciers have retreated and 10% permafrost has degraded. The overall mean active layer depth (ALD) rate increase over the Plateau is 1.4 cm yr-1, 1980-2001, based on model studies and comparison with in situ borehole data. Here we report on the work in progress to quantify ALD rate increase in the northern Tibetan Plateau near the Tibetan national highway, using multi-band SAR/InSAR for improved the thermokarst surface classification, Envisat radar altimetry and ALOS-1 InSAR observed land subsidence, ALD modeling for the various thermokarst surface to relate to subsidence measurements, and the associated validations using available in situ borehole subsidence measurements.

Mitochondrial and chloroplast phylogeography of Picea crassifolia Kom. (Pinaceae) in the Qinghai-Tibetan Plateau and adjacent highlands.

PubMed

Meng, Lihua; Yang, Rui; Abbott, Richard J; Miehe, Georg; Hu, Tianhua; Liu, Jianquan

2007-10-01

The disjunct distribution of forests in the Qinghai-Tibetan Plateau (QTP) and adjacent Helan Shan and Daqing Shan highlands provides an excellent model to examine vegetation shifts, glacial refugia and gene flow of key species in this complex landscape region in response to past climatic oscillations and human disturbance. In this study, we examined maternally inherited mitochondrial DNA (nad1 intron b/c and nad5 intron 1) and paternally inherited chloroplast DNA (trnC-trnD) sequence variation within a dominant forest species, Picea crassifolia Kom. We recovered nine mitotypes and two chlorotypes in a survey of 442 individuals from 32 populations sampled throughout the species' range. Significant mitochondrial DNA population subdivision was detected (G(ST) = 0.512; N(ST) = 0.679), suggesting low levels of recurrent gene flow through seeds among populations and significant phylogeographical structure (N(ST) > GST, P < 0.05). Plateau haplotypes differed in sequence from those in the adjacent highlands, suggesting a long period of allopatric fragmentation between the species in the two regions and the presence of independent refugia in each region during Quaternary glaciations. On the QTP platform, all but one of the disjunct populations surveyed were fixed for the same mitotype, while most populations at the plateau edge contained more than one haplotype with the mitotype that was fixed in plateau platform populations always present at high frequency. This distribution pattern suggests that present-day disjunct populations on the QTP platform experienced a common recolonization history. The same phylogeographical pattern, however, was not detected for paternally inherited chloroplast DNA haplotypes. Two chlorotypes were distributed throughout the range of the species with little geographical population differentiation (G(ST) = N(ST) = 0.093). This provides evidence for highly efficient pollen-mediated gene flow among isolated forest patches, both within and between the QTP and adjacent highland populations. A lack of isolation to pollen-mediated gene flow between forests on the QTP and adjacent highlands is surprising given that the Tengger Desert has been a geographical barrier between these two regions for approximately the last 1.8 million years.

The role of permafrost and soil water in distribution of alpine grassland and its NDVI dynamics on the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, Xiaoyun; Yi, Shuhua; Wu, Qingbai; Yang, Kun; Ding, Yongjian

2016-12-01

Soil temperature and soil water are two important factors controlling vegetation growth. Climate warming and associated permafrost degradation might change these soil conditions and affect alpine grassland on the Qinghai-Tibetan Plateau. However, our current understanding of the role of soil temperature and water at the plateau scale is inadequate. In this study, we used plateau scale soil water content, frozen soil type, vegetation index and land surface temperature datasets to investigate the spatial distribution, limiting factors of vegetation growth and normalized difference vegetation index (NDVI) changing trends in two major alpine grasslands, alpine meadow and alpine steppe, in relation to soil temperature and soil water conditions. Our results showed that: 1) alpine meadow is mainly distributed in seasonal frozen soil areas (55.90% of alpine meadow) with a soil water content between 0.15 and 0.25 m3/m3 and alpine steppe is mainly found in seasonal frozen and sub-stable permafrost areas (69.38% of alpine steppe) with a soil water content between 0.05 and 0.20 m3/m3; 2) at the plateau scale, there were 35.6% (more in colder regions) of alpine meadow pixels and 33.6% (more in wetter regions) of alpine steppe pixels having increase NDVI changing trends during 1982-2012, respectively; and the values having decrease NDVI changing trends are 7.3% and 9.7%, respectively; and 3) the vegetation growth of alpine meadow is mainly limited by soil temperature, while that of alpine steppe is limited by both soil temperature and soil water. We also find the limiting factors of temperature or water can only explain < 50% variation of vegetation growth trends in alpine grasslands. Our findings warrant the use of process-based ecosystem models to consider other factors, such as grazing, erosion and soil texture, among others, in addition to soil temperature and water to make proper projections when simulating the responses of vegetation growth to climate warming in alpine grasslands with different hydro-thermal conditions.

Ali Observatory in Tibet: a unique northern site for future CMB ground-based observations

NASA Astrophysics Data System (ADS)

Su, Meng

2015-08-01

Ground-based CMB observations have been performed at the South Pole and the Atacama desert in Chile. However, a significant fraction of the sky can not be observed from just these two sites. For a full sky coverage from the ground in the future, a northern site for CMB observation, in particular CMB polarization, is required. Besides the long-thought site in Greenland, the high altitude Tibet plateau provides another opportunity. I will describe the Ali Observatory in Tibet, located at N32°19', E80°01', as a potential site for ground-based CMB observations. The new site is located on almost 5100m mountain, near Gar town, where is an excellent site for both infrared and submillimeter observations. Study with the long-term database of ground weather stations and archival satellite data has been performed. The site has enough relative height on the plateau and is accessible by car. The Shiquanhe town is 40 mins away by driving, and a recently opened airport with 40 mins driving, the site also has road excess, electricity, and optical fiber with fast internet. Preliminary measurement of the Precipitable Water Vapor is ~one quarter less than 0.5mm per year and the long term monitoring is under development. In addition, surrounding higher sites are also available and could be further developed if necessary. Ali provides unique northern sky coverage and together with the South Pole and the Atacama desert, future CMB observations will be able to cover the full sky from ground.

Himalayas as seen from STS-66 shuttle Atlantis

NASA Image and Video Library

1994-11-14

View is southeastward across China (Tibet), half of Nepal and India. The partly frozen lake near the center of the frame is Pei-Ku T'so ("Bos-tie Lake"). The central Himalaya stretches from Mount Everest on the left past Annapurna on the right. Large tributaries converge to form the Ganges River, flowing through the lowland basin south of the Himalaya. This photograph illustrates the rain shadow effect of the Himalaya Chain; wet, warm air from the Indian Ocean is driven against the mountains, lifted, and drained of water that forms ice caps, the abundant rivers, and forests of the foothills. In contrast the high plateau of Tibet is arid, composed largely of topographically-closed basins because stream flow is inadequate to form integrated drainage networks.

Impacts of dung combustion on the carbon cycle of alpine grassland of the north Tibetan plateau.

PubMed

Xu, Zengrang; Cheng, Shengkui; Zhen, Lin; Pan, Ying; Zhang, Xianzhou; Wu, Junxi; Zou, Xiuping; Bijaya, G C Dhruba

2013-08-01

Alpine grassland of Tibet is a frangible ecosystem in terms of carbon (C) emission. Yak dung is an important resident energy with about 80 % of yak dung combusted for energy in the north Tibetan plateau. This paper investigated the impact of dung combustion on the C cycle of the alpine grassland ecosystem in north Tibet, China. During the growing season of 2011, from a field survey and household questionnaires, the main impacts of dung collection for fuel on the C cycle of the ecosystem were identified. (1) The C sequestration and storage capacity, including the dung-derived C stored in soil and C captured by vegetation, decreased. The net primary production decreased remarkably because of the reduction of dung returned to soil. (2) In a given period, more C was emitted to the atmosphere in the dung combustion situation than that in the dung returned to soil situation. (3) The energy grazing alpine meadow ecosystem changed into a net C source, and the net biome production of the ecosystem dropped to -15.18 g C/m2 year in the dung combustion situation, 42.95 g C/m2 year less than that in the dung returned situation. To reduce the CO2 emission derived from dung use, the proportion of dung combustion should be reduced and alternative renewable energy such as solar, wind, or hydro energy should be advocated, which is suitable for, and accessible to, the north Tibetan plateau.

Impacts of Dung Combustion on the Carbon Cycle of Alpine Grassland of the North Tibetan Plateau

NASA Astrophysics Data System (ADS)

Xu, Zengrang; Cheng, Shengkui; Zhen, Lin; Pan, Ying; Zhang, Xianzhou; Wu, Junxi; Zou, Xiuping; Bijaya, G. C. Dhruba

2013-08-01

Alpine grassland of Tibet is a frangible ecosystem in terms of carbon (C) emission. Yak dung is an important resident energy with about 80 % of yak dung combusted for energy in the north Tibetan plateau. This paper investigated the impact of dung combustion on the C cycle of the alpine grassland ecosystem in north Tibet, China. During the growing season of 2011, from a field survey and household questionnaires, the main impacts of dung collection for fuel on the C cycle of the ecosystem were identified. (1) The C sequestration and storage capacity, including the dung-derived C stored in soil and C captured by vegetation, decreased. The net primary production decreased remarkably because of the reduction of dung returned to soil. (2) In a given period, more C was emitted to the atmosphere in the dung combustion situation than that in the dung returned to soil situation. (3) The energy grazing alpine meadow ecosystem changed into a net C source, and the net biome production of the ecosystem dropped to -15.18 g C/m2 year in the dung combustion situation, 42.95 g C/m2 year less than that in the dung returned situation. To reduce the CO2 emission derived from dung use, the proportion of dung combustion should be reduced and alternative renewable energy such as solar, wind, or hydro energy should be advocated, which is suitable for, and accessible to, the north Tibetan plateau.

Biogeographic history and high-elevation adaptations inferred from the mitochondrial genome of Glyptosternoid fishes (Sisoridae, Siluriformes) from the southeastern Tibetan Plateau.

PubMed

Ma, Xiuhui; Kang, Jingliang; Chen, Weitao; Zhou, Chuanjiang; He, Shunping

2015-10-28

The distribution of the Chinese Glyptosternoid catfish is limited to the rivers of the Tibetan Plateau and peripheral regions, especially the drainage areas of southeastern Tibet. Therefore, Glyptosternoid fishes are ideal for reconstructing the geological history of the southeastern Tibet drainage patterns and mitochondrial genetic adaptions to high elevations. Our phylogenetic results support the monophyly of the Sisoridae and the Glyptosternoid fishes. The reconstructed ancestral geographical distribution suggests that the ancestral Glyptosternoids was widely distributed throughout the Brahmaputra drainage in the eastern Himalayas and Tibetan area during the Late Miocene (c. 5.5 Ma). We found that the Glyptosternoid fishes lineage had a higher ratio of nonsynonymous to synonymous substitutions than those found in non-Glyptosternoids. In addition, ωpss was estimated to be 10.73, which is significantly higher than 1 (p-value 0.0002), in COX1, which indicates positive selection in the common ancestral branch of Glyptosternoid fishes in China. We also found other signatures of positive selection in the branch of specialized species. These results imply mitochondrial genetic adaptation to high elevations in the Glyptosternoids. We reconstructed a possible scenario for the southeastern Tibetan drainage patterns based on the adaptive geographical distribution of the Chinese Glyptosternoids in this drainage. The Glyptosternoids may have experienced accelerated evolutionary rates in mitochondrial genes that were driven by positive selection to better adapt to the high-elevation environment of the Tibetan Plateau.

Newly discovered Late Triassic Baqing eclogite in central Tibet indicates an anticlockwise West-East Qiangtang collision.

PubMed

Zhang, Yu-Xiu; Jin, Xin; Zhang, Kai-Jun; Sun, Wei-Dong; Liu, Jian-Ming; Zhou, Xiao-Yao; Yan, Li-Long

2018-01-17

The Triassic eclogite-bearing central Qiangtang metamorphic belt (CQMB) in the northern Tibetan Plateau has been debated whether it is a metamorphic core complex underthrust from the Jinsha Paleo-Tethys or an in-situ Shuanghu suture. The CQMB is thus a key issue to elucidate the crustal architecture of the northern Tibetan Plateau, the tectonics of the eastern Tethys, and the petrogenesis of Cenozoic high-K magmatism. We here report the newly discovered Baqing eclogite along the eastern extension of the CQMB near the Baqing town, central Tibet. These eclogites are characterized by the garnet + omphacite + rutile + phengite + quartz assemblages. Primary eclogite-facies metamorphic pressure-temperature estimates yield consistent minimum pressure of 25 ± 1 kbar at 730 ± 60 °C. U-Pb dating on zircons that contain inclusions (garnet + omphacite + rutile + phengite) gave eclogite-facies metamorphic ages of 223 Ma. The geochemical continental crustal signature and the presence of Paleozoic cores in the zircons indicate that the Baqing eclogite formed by continental subduction and marks an eastward-younging anticlockwise West-East Qiangtang collision along the Shuanghu suture from the Middle to Late Triassic.

Lake-levels, vegetation and climate in Central Asia during the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Amosov, Mikhail

2014-05-01

Central Asian region is bounded in the east corner of the Greater Khingan Range and the Loess Plateau, and to the west - the Caspian Sea. This representation of region boundaries is based on classical works of A.Humboldt and V.Obruchev. Three typical features of Central Asia nature are: climate aridity, extensive inland drainage basins with numerous lakes and mountain systems with developed glaciation. Nowadays the extensive data is accumulated about lake-levels during the Last Glacial Maximum (LGM) in Central Asia. Data compilation on 20 depressions, where lakes exist now or where they existed during LGM, shows that most of them had usually higher lake-level than at present time. This regularity could be mentioned for the biggest lakes (the Aral Sea, the Balkhash, the Ysyk-Kol etc.) and for small ones that located in the mountains (Tien Shan, Pamir and Tibet). All of these lake basins get the precipitation due to westerlies. On the other hand lakes, which are located in region's east rimland (Lake Qinghai and lakes in Inner Mongolia) and get the precipitation due to summer East Asian monsoons, do not comply with the proposed regularity. During LGM these lake-levels were lower than nowadays. Another exception is Lake Manas, its lake-level was also lowered. Lake Manas is situated at the bottom of Junggar Basin. There are many small rivers, which come from the ranges and suffer the violent fluctuation in the position of its lower channel. It is possible to assume that some of its runoff did not get to Lake Manas during LGM. Mentioned facts suggest that levels of the most Central Asian lakes were higher during LGM comparing to their current situation. However, at that period vegetation was more xerophytic than now. Pollen data confirm this information for Tibet, Pamir and Tien Shan. Climate aridization of Central Asia can be proved by data about the intensity of loess accumulation during LGM. This evidence received for the east part of region (the Loess Plateau) and for its west part (the piedmonts of Tien Shan and Pamir Mountains). So it confirms a synchronous aridization in different parts of Central Asia. It was the result of amplification of winter Siberian anticyclone, weakening westerlies and East Asian summer monsoons. The observed discrepancy between vegetation conditions and lake-levels during LGM can be explained by lake-levels dependence on runoff as now from mountains, where snow and glaciers melt. Investigations in the area of Mongun Tayga (Tyva Republic in Russian Federation, Lake Hyargas Nuur basin) suggest that precipitation decreased by 30% during LGM, but at the same time snow accumulation increased due to lower temperature in mountains. Thus, special conditions were provided for climate cryoaridization, when vegetation was degraded due to lowering precipitation, but lake-levels grew due to higher runoff from mountain ranges.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-01

Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau.

PubMed

Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

2016-01-07

Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

Erosion in southern Tibet shut down at ∼10 Ma due to enhanced rock uplift within the Himalaya

PubMed Central

Tremblay, Marissa M.; Fox, Matthew; Schmidt, Jennifer L.; Tripathy-Lang, Alka; Wielicki, Matthew M.; Harrison, T. Mark; Zeitler, Peter K.; Shuster, David L.

2015-01-01

Exhumation of the southern Tibetan plateau margin reflects interplay between surface and lithospheric dynamics within the Himalaya–Tibet orogen. We report thermochronometric data from a 1.2-km elevation transect within granitoids of the eastern Lhasa terrane, southern Tibet, which indicate rapid exhumation exceeding 1 km/Ma from 17–16 to 12–11 Ma followed by very slow exhumation to the present. We hypothesize that these changes in exhumation occurred in response to changes in the loci and rate of rock uplift and the resulting southward shift of the main topographic and drainage divides from within the Lhasa terrane to their current positions within the Himalaya. At ∼17 Ma, steep erosive drainage networks would have flowed across the Himalaya and greater amounts of moisture would have advected into the Lhasa terrane to drive large-scale erosional exhumation. As convergence thickened and widened the Himalaya, the orographic barrier to precipitation in southern Tibet terrane would have strengthened. Previously documented midcrustal duplexing around 10 Ma generated a zone of high rock uplift within the Himalaya. We use numerical simulations as a conceptual tool to highlight how a zone of high rock uplift could have defeated transverse drainage networks, resulting in substantial drainage reorganization. When combined with a strengthening orographic barrier to precipitation, this drainage reorganization would have driven the sharp reduction in exhumation rate we observe in southern Tibet. PMID:26371325

Convergent, Parallel and Correlated Evolution of Trophic Morphologies in the Subfamily Schizothoracinae from the Qinghai-Tibetan Plateau

PubMed Central

Qi, Delin; Chao, Yan; Guo, Songchang; Zhao, Lanying; Li, Taiping; Wei, Fulei; Zhao, Xinquan

2012-01-01

Schizothoracine fishes distributed in the water system of the Qinghai-Tibetan plateau (QTP) and adjacent areas are characterized by being highly adaptive to the cold and hypoxic environment of the plateau, as well as by a high degree of diversity in trophic morphology due to resource polymorphisms. Although convergent and parallel evolution are prevalent in the organisms of the QTP, it remains unknown whether similar evolutionary patterns have occurred in the schizothoracine fishes. Here, we constructed for the first time a tentative molecular phylogeny of the schizothoracine fishes based on the complete sequences of the cytochrome b gene. We employed this molecular phylogenetic framework to examine the evolution of trophic morphologies. We used Pagel's maximum likelihood method to estimate the evolutionary associations of trophic morphologies and food resource use. Our results showed that the molecular and published morphological phylogenies of Schizothoracinae are partially incongruent with respect to some intergeneric relationships. The phylogenetic results revealed that four character states of five trophic morphologies and of food resource use evolved at least twice during the diversification of the subfamily. State transitions are the result of evolutionary patterns including either convergence or parallelism or both. Furthermore, our analyses indicate that some characters of trophic morphologies in the Schizothoracinae have undergone correlated evolution, which are somewhat correlated with different food resource uses. Collectively, our results reveal new examples of convergent and parallel evolution in the organisms of the QTP. The adaptation to different trophic niches through the modification of trophic morphologies and feeding behaviour as found in the schizothoracine fishes may account for the formation and maintenance of the high degree of diversity and radiations in fish communities endemic to QTP. PMID:22470515

The impacts of climate change and human activities on biogeochemical cycles on the Qinghai-Tibetan Plateau.

PubMed

Chen, Huai; Zhu, Qiuan; Peng, Changhui; Wu, Ning; Wang, Yanfen; Fang, Xiuqing; Gao, Yongheng; Zhu, Dan; Yang, Gang; Tian, Jianqing; Kang, Xiaoming; Piao, Shilong; Ouyang, Hua; Xiang, Wenhua; Luo, Zhibin; Jiang, Hong; Song, Xingzhang; Zhang, Yao; Yu, Guirui; Zhao, Xinquan; Gong, Peng; Yao, Tandong; Wu, Jianghua

2013-10-01

With a pace of about twice the observed rate of global warming, the temperature on the Qinghai-Tibetan Plateau (Earth's 'third pole') has increased by 0.2 °C per decade over the past 50 years, which results in significant permafrost thawing and glacier retreat. Our review suggested that warming enhanced net primary production and soil respiration, decreased methane (CH(4)) emissions from wetlands and increased CH(4) consumption of meadows, but might increase CH(4) emissions from lakes. Warming-induced permafrost thawing and glaciers melting would also result in substantial emission of old carbon dioxide (CO(2)) and CH(4). Nitrous oxide (N(2)O) emission was not stimulated by warming itself, but might be slightly enhanced by wetting. However, there are many uncertainties in such biogeochemical cycles under climate change. Human activities (e.g. grazing, land cover changes) further modified the biogeochemical cycles and amplified such uncertainties on the plateau. If the projected warming and wetting continues, the future biogeochemical cycles will be more complicated. So facing research in this field is an ongoing challenge of integrating field observations with process-based ecosystem models to predict the impacts of future climate change and human activities at various temporal and spatial scales. To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus biogeochemical cycles as well as about the role of microbes in these cycles. © 2013 John Wiley & Sons Ltd.

Population transcriptomes reveal synergistic responses of DNA polymorphism and RNA expression to extreme environments on the Qinghai-Tibetan Plateau in a predatory bird.

PubMed

Pan, Shengkai; Zhang, Tongzuo; Rong, Zhengqin; Hu, Li; Gu, Zhongru; Wu, Qi; Dong, Shanshan; Liu, Qiong; Lin, Zhenzhen; Deutschova, Lucia; Li, Xinhai; Dixon, Andrew; Bruford, Michael W; Zhan, Xiangjiang

2017-06-01

Low oxygen and temperature pose key physiological challenges for endotherms living on the Qinghai-Tibetan Plateau (QTP). Molecular adaptations to high-altitude living have been detected in the genomes of Tibetans, their domesticated animals and a few wild species, but the contribution of transcriptional variation to altitudinal adaptation remains to be determined. Here we studied a top QTP predator, the saker falcon, and analysed how the transcriptome has become modified to cope with the stresses of hypoxia and hypothermia. Using a hierarchical design to study saker populations inhabiting grassland, steppe/desert and highland across Eurasia, we found that the QTP population is already distinct despite having colonized the Plateau <2000 years ago. Selection signals are limited at the cDNA level, but of only seventeen genes identified, three function in hypoxia and four in immune response. Our results show a significant role for RNA transcription: 50% of upregulated transcription factors were related to hypoxia responses, differentiated modules were significantly enriched for oxygen transport, and importantly, divergent EPAS1 functional variants with a refined co-expression network were identified. Conservative gene expression and relaxed immune gene variation may further reflect adaptation to hypothermia. Our results exemplify synergistic responses between DNA polymorphism and RNA expression diversity in coping with common stresses, underpinning the successful rapid colonization of a top predator onto the QTP. Importantly, molecular mechanisms underpinning highland adaptation involve relatively few genes, but are nonetheless more complex than previously thought and involve fine-tuned transcriptional responses and genomic adaptation. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Streptomyces lacrimifluminis sp. nov., a novel actinobacterium that produces antibacterial compounds, isolated from soil.

PubMed

Zhang, Binglin; Tang, Shukun; Chen, Ximing; Zhang, Ling; Zhang, Gaoseng; Zhang, Wei; Liu, Guangxiu; Chen, Tuo; Li, Shiweng; Dyson, Paul

2016-12-01

A novel actinobacterial strain, designated Z1027T, was isolated from a soil sample collected near the Tuotuo River, Qinghai-Tibet Plateau (China). The strain exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The taxonomic position of strain Z1027T was determined using a polyphasic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the 16S rRNA gene tree, together with Streptomyces turgidiscabies ATCC 700248T (99.19 % similarity), Streptomyces graminilatus JL-6T (98.84 %) and Streptomyces reticuliscabiei CFBP 4531T (98.36 %). The genomic DNA G+C content of strain Z1027T was 74±1 mol%. The DNA-DNA relatedness values between strain Z1027T and Streptomyces turgidiscabies ATCC 700248T and Streptomyces reticuliscabiei CFBP 4531T were 38.5±0.4 and 26.2±1.2 %, respectively, both of them significantly lower than 70 %. Chemotaxonomic data revealed that strain Z1027T possessed MK-9(H6) and MK-9(H8) as the major menaquinones, ll-diaminopimelic acid as the diagnostic diamino acid and galactose as a whole-cell sugar. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatydilinositol and seven other unknown polar lipids were detected; iso-C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 were the major fatty acids. On the basis of these genotypic and phenotypic data, it is proposed that isolate Z1027T (=CGMCC 4.7272T=JCM 31054T) should be classified as the type strain of a novel species of the genus Streptomyces,Streptomyces lacrimifluminis sp. nov.

Research Analysis of temporal and spatial characteristics of eco-environmental vulnerability in the Xianshui River basin based on GIS

NASA Astrophysics Data System (ADS)

Yao, Kun; Bai, Lin; Li, Xiao Ju; Wang, Xiao

2018-05-01

The Xianshui River basin is an important ecological barrier and water conservation area of Qinghai-Tibet plateau. To master the spatial and temporal differentiation of ecological environment is beneficial to the realization of the protection of regional ecological environment and the development of restoration measures. In this paper, the evaluation index system of ecological environment vulnerability was constructed from topography, climate, soil, land use and social economy. In this study, GIS and information entropy theory are combined to complete the analysis of spatial and temporal variation of vulnerability of ecological environment vulnerability in 2000-2015 years, and the main results are as follows: The ecological vulnerability of the watershed is characterized by the obvious vertical distribution, which is characterized by the gradual increase of the vulnerability of the south to the north. The evaluation results were classified as potential, micro, mild, moderate and severe, with the proportion of each grade being Micro > mild > potential > moderate > severity. The proportion of light and below accounts for more than 80% of the whole area, and the whole basin is at a medium vulnerable level. The change of overall trend indicates that the overall ecological environment of the basin has improved obviously in 15 years. The driving force factor analysis shows that the national environmental protection and restoration project is playing a significant role and plays a major driving role in the obvious improvement of the ecological environment in the basin area. However, there are still a few parts of the region that are deteriorating. This is mainly due to the special natural environment and over exploitation of hydropower resources.

[Geographic patterns and ecological factors correlates of snake species richness in China].

PubMed

Cai, Bo; Huang, Yong; Chen, Yue-Ying; Hu, Jun-Hua; Guo, Xian-Guang; Wang, Yue-Zhao

2012-08-01

Understanding large-scale geographic patterns of species richness as well its underlying mechanisms are among the most significant objectives of macroecology and biogeography. The ecological hypothesis is one of the most accepted explanations of this mechanism. Here, we studied the geographic patterns of snakes and investigated the relationships between species richness and ecological factors in China at a spatial resolution of 100 km×100 km. We obtained the eigenvector-based spatial filters by Principal Coordinates Neighbor Matrices, and then analyzed ecological factors by multiple regression analysis. The results indicated several things: (1) species richness of snakes showed multi-peak patterns along both the latitudinal and longitudinal gradient. The areas of highest richness of snake are tropics and subtropical areas of Oriental realm in China while the areas of lowest richness are Qinghai-Tibet Plateau, the grasslands and deserts in northern China, Yangtze-Huai Plain, Two-lake Plain, and the Poyang-lake Plain; (2) results of multiple regression analysis explained a total of 56.5% variance in snake richness. Among ecological factors used to explore the species richness patterns, we found the best factors were the normalized difference vegetation index, precipitation in the coldest quarter and temperature annual range ; (3) our results indicated that the model based on the significant variables that (P<0.05) uses a combination of precipitation of coldest quarter, normalized difference vegetation index and temperature annual range is the most parsimonious model for explaining the mechanism of snake richness in China. This finding demonstrates that different ecological factors work together to affect the geographic distribution of snakes in China. Studying the mechanisms that underlie these geographic patterns are complex, so we must carefully consider the choice of impact-factors and the influence of human activities.

Analysis on the Change of Grassland Coverage in the Source Region of Three Rivers during 2000-2012

NASA Astrophysics Data System (ADS)

Luo, Chengfeng; Wang, Jiao; Liu, Meilin; Liu, Zhengjun

2014-03-01

The Source Region of Three Rivers (SRTR) has very important ecological functions which form an ecological security barrier for China's Qinghai-Tibet plateau. As the biggest nationally occuring nature reserve region in China, the ecological environment here is very fragile. In SRTR the grassland coverage is an effective detector to reflect the ecological environment condition, because it records the changing process of climatic and environmental sensitively. In recent years SRTR has been suffering pressures from both nature and social pressures. With MODIS data the study monitored the grassland coverage continuously in SRTR from 2000 to 2012. The density-model was adapted to estimate grassland coverage degree firstly. Then the degree of change and the change intensity, change type were used to judge the grassland coverage change trend comprehensively. For grassland coverage there was natural change annual or within the year, and the degree of change was used to judge if there was change or not. The grassland has another important characteristic, annual fluctuation, and it can be differed from sustained changes with change type. For grassland coverage, such continuous change, like improvement or degradation, and to what extent, has more guidance sense on specific production practice. On the base of change type and degree of change, change intensity was used to identify the change trend of the grassland coverage. The analysis results from our study show that steady state and fluctuation are two main change trends for the vegetation coverage in SRTR from 2000 to 2012. The conclusion of this paper can provide references in response to environment change research and in the regional ecological environmental protection project in SRTR.

Nitrogen deposition and its effect on carbon storage in Chinese forests during 1981-2010

NASA Astrophysics Data System (ADS)

Gu, Fengxue; Zhang, Yuandong; Huang, Mei; Tao, Bo; Yan, Huimin; Guo, Rui; Li, Jie

2015-12-01

Human activities have resulted in dramatically increased nitrogen (N) deposition worldwide, which is closely linked to the carbon (C)-cycle processes and is considered to facilitate terrestrial C sinks. In this study, we firstly estimated the spatial and temporal variations of N deposition during 1981-2010 based on a new algorithm; then we used a newly improved process-based ecosystem model, CEVSA2, to examine the effects of N deposition on C storage in Chinese forests. The results show that the rate of N deposition increased by 0.058 g N m-2 yr-1 between 1981 and 2010. The N deposition rate in 2010 was 2.32 g N m-2 yr-1, representing a large spatial variation from 0 to 0.25 g N m-2 yr-1 on the northwestern Qinghai-Tibet Plateau to over 4.5 g N m-2 yr-1 in the southeastern China. The model simulations suggest that N deposition induced a 4.78% increase in the total C storage in Chinese forests, most of which accumulated in vegetation. C storage increased together with the increase in N deposition, in both space and time. However, N use efficiency was highest when N deposition was 0.4-1.0 g N m-2 yr-1. We suggest conducting more manipulation experiments and observations in different vegetation types, which will be greatly helpful to incorporate additional processes and mechanisms into the ecosystem modeling. Further development of ecosystem models and identification of C-N interactions will be important for determining the effects of N input on C cycles on both regional and global scales.

Vertical patterns and controls of soil nutrients in alpine grassland: Implications for nutrient uptake.

PubMed

Tian, Liming; Zhao, Lin; Wu, Xiaodong; Fang, Hongbing; Zhao, Yonghua; Yue, Guangyang; Liu, Guimin; Chen, Hao

2017-12-31

Vertical patterns and determinants of soil nutrients are critical to understand nutrient cycling in high-altitude ecosystems; however, they remain poorly understood in the alpine grassland due to lack of systematic field observations. In this study, we examined vertical distributions of soil nutrients and their influencing factors within the upper 1m of soil, using data of 68 soil profiles surveyed in the alpine grassland of the eastern Qinghai-Tibet Plateau. Soil organic carbon (SOC) and total nitrogen (TN) stocks decreased with depth in both alpine meadow (AM) and alpine steppe (AS), but remain constant along the soil profile in alpine swamp meadow (ASM). Total phosphorus, Ca 2+ , and Mg 2+ stocks slightly increased with depth in ASM. K + stock decreased with depth, while Na + stock increased slightly with depth among different vegetation types; however, SO 4 2- and Cl - stocks remained relatively uniform throughout different depth intervals in the alpine grassland. Except for SOC and TN, soil nutrient stocks in the top 20cm soils were significantly lower in ASM compared to those in AM and AS. Correlation analyses showed that SOC and TN stocks in the alpine grassland positively correlated with vegetation coverage, soil moisture, clay content, and silt content, while they negatively related to sand content and soil pH. However, base cation stocks revealed contrary relationships with those environmental variables compared to SOC and TN stocks. These correlations varied between vegetation types. In addition, no significant relationship was detected between topographic factors and soil nutrients. Our findings suggest that plant cycling and soil moisture primarily control vertical distributions of soil nutrients (e.g. K) in the alpine grassland and highlight that vegetation types in high-altitude permafrost regions significantly affect soil nutrients. Copyright © 2017 Elsevier B.V. All rights reserved.

Species richness of Eurasian Zephyrus hairstreaks (Lepidoptera: Lycaenidae: Theclini) with implications on historical biogeography: An NDM/VNDM approach

PubMed Central

Yago, Masaya; Settele, Josef; Li, Xiushan; Ueshima, Rei; Grishin, Nick V.; Wang, Min

2018-01-01

Aim A database based on distributional records of Eurasian Zephyrus hairstreaks (Lepidoptera: Lycaenidae: Theclini) was compiled to analyse their areas of endemism (AoEs), species richness and distribution patterns, to explore their locations of past glacial refugia and dispersal routes. Methods Over 2000 Zephyrus hairstreaks occurrences are analysed using the NDM/VNDM algorithm, for the recognition of AoEs. Species richness was calculated by using the option ‘Number of different classes’ to count the different classes of a variable presented in each 3.0°×3.0° grid cell, and GIS software was used to visualize distribution patterns of endemic species. Results Centres of species richness of Zephyrus hairstreaks are situated in the eastern Qinghai-Tibet Plateau (EQTP), Hengduan Mountain Region (HDMR) and the Qinling Mountain Region (QLMR). Latitudinal gradients in species richness show normal distribution with the peak between 25° N and 35° N in the temperate zone, gradually decreasing towards the poles. Moreover, most parts of central and southern China, especially the area of QLMR-EQTP-HDMR, were identified as AoEs that may have played a significant role as refugia during Quaternary global cooling. There are four major distributional patterns of Zephyrus hairstreaks in Eurasia: Sino-Japanese, Sino-Himalayan, high-mountain and a combined distribution covering all three patterns. Conclusions Zephyrus hairstreaks probably originated at least 23–24 Myr ago in E. Asia between 25° N to 35° N in the temperate zone. Cenozoic orogenies caused rapid speciation of this tribe and extrusion of the Indochina block resulted in vicariance between the Sino-Japanese and the Sino-Himalayan patterns. The four distribution patterns provided two possible dispersal directions: Sino-Japanese dispersal and Sino-Himalayan dispersal. PMID:29351314

Species richness of Eurasian Zephyrus hairstreaks (Lepidoptera: Lycaenidae: Theclini) with implications on historical biogeography: An NDM/VNDM approach.

PubMed

Zhuang, Hailing; Yago, Masaya; Settele, Josef; Li, Xiushan; Ueshima, Rei; Grishin, Nick V; Wang, Min

2018-01-01

A database based on distributional records of Eurasian Zephyrus hairstreaks (Lepidoptera: Lycaenidae: Theclini) was compiled to analyse their areas of endemism (AoEs), species richness and distribution patterns, to explore their locations of past glacial refugia and dispersal routes. Over 2000 Zephyrus hairstreaks occurrences are analysed using the NDM/VNDM algorithm, for the recognition of AoEs. Species richness was calculated by using the option 'Number of different classes' to count the different classes of a variable presented in each 3.0°×3.0° grid cell, and GIS software was used to visualize distribution patterns of endemic species. Centres of species richness of Zephyrus hairstreaks are situated in the eastern Qinghai-Tibet Plateau (EQTP), Hengduan Mountain Region (HDMR) and the Qinling Mountain Region (QLMR). Latitudinal gradients in species richness show normal distribution with the peak between 25° N and 35° N in the temperate zone, gradually decreasing towards the poles. Moreover, most parts of central and southern China, especially the area of QLMR-EQTP-HDMR, were identified as AoEs that may have played a significant role as refugia during Quaternary global cooling. There are four major distributional patterns of Zephyrus hairstreaks in Eurasia: Sino-Japanese, Sino-Himalayan, high-mountain and a combined distribution covering all three patterns. Zephyrus hairstreaks probably originated at least 23-24 Myr ago in E. Asia between 25° N to 35° N in the temperate zone. Cenozoic orogenies caused rapid speciation of this tribe and extrusion of the Indochina block resulted in vicariance between the Sino-Japanese and the Sino-Himalayan patterns. The four distribution patterns provided two possible dispersal directions: Sino-Japanese dispersal and Sino-Himalayan dispersal.

Sequoia maguanensis, a new Miocene relative of the coast redwood, Sequoia sempervirens, from China: implications for paleogeography and paleoclimate.

PubMed

Zhang, Jian-Wei; D'Rozario, Ashalata; Adams, Jonathan M; Li, Ya; Liang, Xiao-Qing; Jacques, Frédéric M; Su, Tao; Zhou, Zhe-Kun

2015-01-01

• The paleogeographical origin of the relict North American Sequoia sempervirens is controversial. Fossil records indicate a Neogene origin for its foliage characteristics. Although several fossils from the Miocene sediments in eastern Asia have been considered to have close affinities with the modern S. sempervirens, they lack the typical features of a leafy twig bearing linear as well as scale leaves, and the fertile shoots terminating by a cone. The taxonomic status of these fossils has remained unclear.• New better-preserved fossils from the upper Miocene of China indicate a new species of Sequoia. This finding not only confirms the former presence of this genus in eastern Asia, but it also confirms the affinity of this Asian form to the modern relict S. sempervirens.• The principal foliage characteristics of S. sempervirens had already originated by the late Miocene. The eastern Asian records probably imply a Beringian biogeographic track of the ancestor of S. sempervirens in the early Neogene, at a time when the land bridge was not too cool for this thermophilic conifer to spread between Asia and North America.• The climatic context of the new fossil Sequoia in Southeast Yunnan, based on other floristic elements of the fossil assemblage in which it is found, is presumed to be warm and humid. Following the uplift of the Qinghai-Tibet Plateau, this warm, humid climate was replaced by the present monsoonal climate with dry winter and spring. This change may have led to the disappearance of this hygrophilous conifer from eastern Asia. © 2015 Botanical Society of America, Inc.

Air Stagnations for China (1985-2014): Climatological Mean Features and Trends

NASA Astrophysics Data System (ADS)

Huang, Qianqian; Cai, Xuhui; Song, Yu; Zhu, Tong

2017-04-01

Air stagnation is an important meteorological measurement for unfavourable air pollution conditions, but little is known about it in China. We conducted a comprehensive investigation of air stagnation in China, based on sounding and surface observations of 81 stations, from January 1985 to December 2014. The stagnation criteria were revised to be topographically dependent for the great physical diversity in this country. It is found that the annual mean air stagnation occurrences are closely related to general topography and climate features. Two basins in the northwest and southwest of China—Tarim and Sichuan Basins—exhibit the most frequent stagnation occurrence (50% days per year), whereas two plateaus (Tibet-Qinghai and Inner Mongolia Plateau) and the east coastal areas experience the least (20% days per year). Over the whole country, air stagnations achieve maxima in summer and minima in winter, except for Urumqi, a major city in the northwest of China, where stagnations keep a rather constant value yearly around with a minimum in spring. There is a nationwide positive trend in stagnation occurrence during 1985-2014, with the strongest increasing centres over Shandong Peninsula in eastern China and the south of Shaanxi in central China. Dependence degrees of air stagnations on three components (upper- and lower-air winds, precipitation-free days) are examined. It shows that the spatial distribution and trend of air stagnations are mainly driven by the behaviours of upper-air wind speeds. Air stagnation climatology presents a specific view to the natural background of atmosphere features being responsible to air pollution levels. The results presented in this paper may have significant implication to air pollution research, and may be used in atmospheric environment management or air pollution control.