Science.gov

Sample records for mountains northwestern china

  1. Microchemical Study of Pigments and Binders in Polychrome Relics from Maiji Mountain Grottoes in Northwestern China.

    PubMed

    Liu, Luyao; Shen, Wei; Zhang, Bingjian; Ma, Qian

    2016-08-01

    In this study, an integrated analytical method was developed to investigate the composition of both the inorganic pigments and organic binders of polychrome relics in Maiji Mountain Grottoes in northwestern China. Cross-sections of each sample were prepared at the beginning of the study, and all experiments were carried out on these cross-sections. Polychromic structures were revealed by optical microscopy and scanning electron microscopy-backscattered electron imaging. Inorganic materials were determined by using SEM coupled with an energy dispersive spectrometer and μ-Raman spectrometer, whereas organic materials were identified by staining techniques and highly sensitive and specific immunofluorescence microscopy. Data showed that the red colors are attributed to one or two pigments of red ochre, cinnabar, and minium; the blue pigment is natural lazurite; the green pigment is ascribed to atacamite; the white color is attributed to potassium feldspar; and the black surface is formed by the discoloration of minium to plattnerite under the influence of environmental factors. Regarding organic binders used in painting and preparation layers, mammalian animal glue and chicken egg white were both found alone or in mixture. Finally, the conclusion is made that the Secco technique is employed in polychrome relics from Maiji Mountain Grottoes.

  2. Microchemical Study of Pigments and Binders in Polychrome Relics from Maiji Mountain Grottoes in Northwestern China.

    PubMed

    Liu, Luyao; Shen, Wei; Zhang, Bingjian; Ma, Qian

    2016-08-01

    In this study, an integrated analytical method was developed to investigate the composition of both the inorganic pigments and organic binders of polychrome relics in Maiji Mountain Grottoes in northwestern China. Cross-sections of each sample were prepared at the beginning of the study, and all experiments were carried out on these cross-sections. Polychromic structures were revealed by optical microscopy and scanning electron microscopy-backscattered electron imaging. Inorganic materials were determined by using SEM coupled with an energy dispersive spectrometer and μ-Raman spectrometer, whereas organic materials were identified by staining techniques and highly sensitive and specific immunofluorescence microscopy. Data showed that the red colors are attributed to one or two pigments of red ochre, cinnabar, and minium; the blue pigment is natural lazurite; the green pigment is ascribed to atacamite; the white color is attributed to potassium feldspar; and the black surface is formed by the discoloration of minium to plattnerite under the influence of environmental factors. Regarding organic binders used in painting and preparation layers, mammalian animal glue and chicken egg white were both found alone or in mixture. Finally, the conclusion is made that the Secco technique is employed in polychrome relics from Maiji Mountain Grottoes. PMID:27485573

  3. Climate-driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China.

    PubMed

    Qi, Zhaohuan; Liu, Hongyan; Wu, Xiuchen; Hao, Qian

    2015-02-01

    Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand-total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming-induced treeline dynamics.

  4. Distribution of ammonia oxidizers in relation to vegetation characteristics in the Qilian Mountains, northwestern China

    NASA Astrophysics Data System (ADS)

    Tai, X. S.; Mao, W. L.; Liu, G. X.; Chen, T.; Zhang, W.; Wu, X. K.; Long, H. Z.; Zhang, B. G.; Gao, T. P.

    2014-04-01

    Nitrogen is the major limiting nutrient in cold environments, and its availability is strongly dependent on nitrification. However, microbial communities driving this process remain largely uncharacterized in alpine meadow soils in northwestern China, namely those catalyzing the rate-limiting step of ammonia oxidation. In this study, ammonia-oxidizing communities in alpine meadow soils were characterized by real-time PCR and clone sequencing by targeting on amoA genes, which putatively encode ammonia monooxygenase subunit A. The results demonstrated that ammonia-oxidizing archaea (AOA) outnumbered ammonia-oxidizing bacteria (AOB) in the alpine meadow soils. Most of the AOA phylotypes detected in the study region fell within typical Group I.1b of Thaumarchaeota. Interestingly, a new ammonia-oxidizing archaeal group named "Kobresia meadow soil group" was found. Phylogenetic analysis of AOB communities exhibited a dominance of Nitrosospira-like sequences affiliated to beta-Proteobacteria. Compared with other alpine environments, Qilian Mountains had a great phylogenetic diversity of ammonia oxidizers. Principal Component Analysis (PCA) analysis showed that distinct AOA/AOB phylotype groups were attributed to different meadow types, reflecting an overall distribution of ammonia-oxidizing communities associated with meadow types. Redundancy Analysis (RDA) analysis showed that Axis 1 (90.9%) together with Axis 2 (9.1%) explained all the variables while Axis 1 exhibited a significant explanatory power. So that vegetation coverage mostly correlated to Axis 1 was the most powerful environmental factor in the study region. Characteristics of ammonia-oxidizing communities showed a close association with vegetation coverage.

  5. Vegetation coverage change and associated driving forces in mountain areas of Northwestern Yunnan, China using RS and GIS.

    PubMed

    Peng, Jian; Liu, Yinghui; Shen, Hong; Han, Yinan; Pan, Yajing

    2012-08-01

    The dynamics of vegetation coverage and associated driving forces are one of the key issues in global environmental change. In the study, taking Lijiang County as a case, the Normalized Difference Vegetation Index was used to quantify vegetation coverage change in mountain areas of Northwestern Yunnan, China, with the application of remote sensing data and GIS technologies. And associated driving forces of vegetation coverage change were also analyzed, with a focus on land use change and elevation. The results showed that there was high vegetation coverage with a significant increase in the whole county during 1986-2002. However, due to economic development and the implementation of environmental protection polices, vegetation coverage change in the county showed distinct spatial diversity, which mainly behaved as the increasing in the northwest of the county with low human activities, and the decreasing in the south with high economic development. The results also showed that as a restrictive factor, elevation was of great signification on the spatial distribution of vegetation coverage in a broad scale; while in the county level, it was land use that determined the vegetation coverage, since the change of vegetation coverage grades in the study area was mainly associated with the change of land use types.

  6. Comparing meteorological records between mountainous and valley bottom sites in the upper reaches of the Heihe River, northwestern China: implications for dendroclimatology

    NASA Astrophysics Data System (ADS)

    Zeng, Qiao; Yang, Bao

    2016-01-01

    Tree-ring records from remote upland areas are widely used in climate reconstructions, but they are typically calibrated by meteorological data from low-lying areas. With the aim of assessing relationships between climatic records from mountainous and valley bottoms, this study compared meteorological records between mountainous sites (lower to upper elevations) and valley bottoms (Qilian (QL) and Yeniugou (YNG)) in the upper reaches of the Heihe River, northwestern China. We found that daily, 5-day, 10-day, and monthly mean air temperatures observed during a 4-year observational period in valley bottoms were strongly correlated (R = 0.90-0.99) to their mountainous site counterparts. Additionally, temperature records from the QL meteorological station shared a higher percentage of variance with each mountainous site compared to YNG. Correlations of precipitation totals between valley bottoms and mountainous sites showed a similar pattern to temperatures. Furthermore, different time series of total rainfall in YNG can explain more variance than those from QL and were also more suitable representations of mountainous sites. Our results confirmed the reliability of utilizing monthly climatic records from valley bottoms to calibrate tree-ring records in mountainous sites. We also caution that when conducting fine-scale microcoring and dendrometer monitoring studies, lower correlations of short-term scale precipitation records between valley bottoms and mountainous sites may introduce unavoidable errors.

  7. Grasshopper (Orthoptera: Acrididae) Community Composition in the Rangeland of the Northern Slopes of the Qilian Mountains in Northwestern China

    PubMed Central

    Sun, T.; Liu, Z. Y.; Qin, L. P.; Long, R. J.

    2015-01-01

    In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species similarity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the Sörensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. PMID:25688084

  8. Tree ring δ18O's indication of a shift to a wetter climate since the 1880s in the western Tianshan Mountains of northwestern China

    NASA Astrophysics Data System (ADS)

    Xu, Guobao; Liu, Xiaohong; Wu, Guoju; Chen, Tuo; Wang, Wenzhi; Zhang, Qiong; Zhang, Youfu; Zeng, Xiaomin; Qin, Dahe; Sun, Weizhen; Zhang, Xuanwen

    2015-07-01

    Central Asian droughts have drastically and significantly affected agriculture and water resource management in these arid and semiarid areas. Based on tree ring δ18O from native, dominant Schrenk spruce (Picea schrenkiana Fisch. et Mey.), we developed a 300 year (1710-2010) standard precipitation-evaporation index (SPEI) reconstruction from January to August for China's western Tianshan Mountains. The regression model explained 37.6% of the variation in the SPEI reconstruction during the calibration period from 1950 to 2010. Comparison with previous drought reconstructions confirmed the robustness of our reconstruction. The 20th century has been a relatively wet period during the past 300 years. The SPEI showed quasi 2, 5, and 10 year cycles. Several pluvials and droughts with covariability over large areas were revealed clearly in the reconstruction. The two longest pluvials (lasting for 12 years), separated by 50 years, appeared in the 1900s and the 1960s. The most severe drought occurred from 1739 to 1761 and from 1886 to 1911 was the wettest period since 1710. Compared to previous investigations of hydroclimatic changes in the western Tianshan Mountains, our reconstruction revealed more low-frequency variability and indicated that climate in the western Tianshan Mountains shifted from dry to wet in 1886. This regime shift was generally consistent with other moisture reconstructions for the northeastern Tibetan Plateau and northern Pakistan and may have resulted from a strengthened westerly circulation. The opposite hydrological trends in the western Tianshan Mountains and southeastern Tibetan Plateau reveal a substantial influence of strengthened westerlies and weakening of the Indian summer monsoon.

  9. Guillain-Barré syndrome in northwestern China.

    PubMed

    Jiang, W; Wang, H D; Huang, Y G; Wan, Q; Xu, Y; Wu, B R

    2001-01-01

    We reviewed 100 patients with Guillan-Barré syndrome (GBS) from 1994 to 2000 from northwestern China. We examined clinical and electro-diagnostics features and compared them to patients from Europe, North America and northern China. Results indicated that among 100 patients with GBS, the demyelinating pattern was present in 51 patients, the axonal pattern in 25 patients, and 8 patients were inexcitable, 12 patients equivocal and 4 patients normal. The electrophysiological and clinical features of various subtypes of GBS in northwestern China seemed to be different in some ways from those in western countries and in northern China. However, in northwestern China, the demyelinating pattern is the major electrophysiological subtype.

  10. Late paleozoic tectonic amalgamation of northwestern China. Sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar basins

    SciTech Connect

    Carroll, A.R.; Graham, S.A.; Hendrix, M.S.; Ying, D.; Zhou, D.

    1995-05-01

    This study focuses on areas adjacent to the Tian Shan (shan is Chinese for mountains) in Xinjiang Uygur Autonomous Region, northwestern China, and provides new field data on Carboniferous and Permian outcrop exposures of sedimentary rocks of the southern Junggar, northwestern Turpan, and northern Tarim basins that bear directly on the history of late Paleozoic tectonic amalgamation. We present here a multifaceted sedimentary basin analysis, including sedimentary facies, paleocurrent, and sandstone provenance analyses, and reconstructions of late Paleozoic basin subsidence. These data provide a unique record not only of the basins themselves, but also of the evolution of the adjacent orogenic belts. This study is based on fieldwork during the summers of 1987, 1988, 1991, and 1992 by workers from Stanford University, the Chinese Academy of Geological Sciences, and the Xinjiang Bureau of Geology and Mineral Resources. Although reconnaissance in nature, the data presented here provide a basis for evaluating alternative hypotheses for the evolution of northwestern China and provide a starting point for more comprehensive future studies. 72 refs., 18 figs., 1 tab.

  11. Geomorphic surfaces in the northwestern Klamath Mountains, California and Oregon

    SciTech Connect

    Baldwin, K.S. ); Ricks, C.L. )

    1993-04-01

    Thick, residual, colluvial and alluvial soils derived from ophiolitic rocks mantle at least four geomorphic surfaces in the Siskiyou and marble mountains, in northwestern California and Illinois Valley, in southwestern Oregon. Analysis of digital elevation data provides constraints on the distribution and origin of these surfaces. Because of the geomorphic expression and soil mechanical properties of the surfaces, a map of slope gradients less than 22 degrees closely approximates the distribution of geomorphic surfaces as they are known from field observations. Preliminary definition of individual surfaces is based upon classification of the slop-map by elevation ranges. The Klamath Peneplain'' of Diller (1902) and associated soils, recently referred to as Klamath Saprolite'', are recognized near summit elevation (1,500 meters) across the area. Regional uplift and erosion has resulted in extensive, large earthflow landslides derived from these soils. Alluvial and residual deposits on the floor of the Illinois Valley occur at the same elevation (300 meters) as incised alluvial and colluvial terrace deposits along the Klamath River and tributary streams. At least two additional surfaces have been identified in the Siskiyou and Marble Mountains at approximately elevation 750 and 1,000 meters. Analysis of digital elevation data, combined with the map of earthflow landslides, allows rapid preliminary mapping of geomorphic surfaces in this terrain.

  12. Deglaciation of the northwestern White Mountains, New Hampshire

    USGS Publications Warehouse

    Thompson, W.B.; Fowler, B.K.; Dorion, C.C.

    1999-01-01

    The mode of deglaciation in the northwestern White Mountains of New Hampshire has been controversial since the mid 1800's. Early workers believed that active ice deposited the Bethlehem Moraine complex in the Ammonoosuc River basin during recession of the last ice sheet. In the 1930's this deglaciation model was replaced by the concept of widespread simultaneous stagnation and downwastage of Late Wisconsinan ice. The present authors reexamined the Bethlehem Moraine complex and support the original interpretation of a series of moraines deposited by active ice. We found other moraine clusters of similar age to the northeast in the Johns River and Israel River basins. Ice-marginal deposits that probably correlate with the Bethlehem Moraine also occur west of Littleton. The Bethlehem Moraine complex and equivalent deposits in adjacent areas were formed by readvance and oscillatory retreat of the Connecticut Valley lobe of the Laurentide Ice Sheet. This event is called the Littleton-Bethlehem Readvance. Throughout the study area, sequences of glaciolacustrine deposits and meltwater drainage channels indicate progressive northward recession of the glacier margin. Radiocarbon dates from nearby New England and Quebec suggest that the ice sheet withdrew from this part of the White Mountains between about 12,500 and 12,000 14C yr BP. We attribute the Littleton-Bethlehem Readvance to a brief climatic cooling during Older Dyas time, close to 12,000 BP.

  13. Mountain goat response to hydroelectric exploration in northwestern British Columbia

    SciTech Connect

    Foster, B.R.; Rahs, E.Y.

    1983-03-01

    The behavioral responses of more than 800 mountain goats, comprised of 195 social groups, were recorded during hydroelectric exploration activities (primarily aircraft) in northwestern British Columbia. Four categories of overt response were recorded during case tests, ranging from maintenance activity to severe flight. More than 80 percent (n=667) of the observed goats elicited some form of behavioral stress-response, with 33 percent (n=265) displaying a severe flight response to local rock or plant cover. Multiple regression analysis inferred goat responses to be statistically independent of the time of year, type, and vertical orientation of disturbance and group size. As expected, significant correlations (p less than or equal to 0.05) existed between distance of disturbance, geographic area, cover availability, and degree of awareness. Responses were stimulated primarily by auditory and secondarily by visual cues. Repeated aerial and ground follow-up surveys documented temporary range abandonment and changing observability indices (habitat use and activity patterns) associated with areas of intense exploration activity. The assessed data offer mitigation possibilities and enable formulation of management guidelines to lessen project impacts during future exploration, construction, and operation phases.

  14. Mountain goat response to hydroelectric exploration in northwestern British Columbia

    NASA Astrophysics Data System (ADS)

    Foster, Bryan R.; Rahs, Engel Y.

    1983-03-01

    The behavioral responses of more than 800 mountain goats, comprised of 195 social groups, were recorded during hydroelectric exploration activities (primarily aircraft) in northwestern British Columbia. Four categories of overt response were recorded during case tests, ranging from maintenance activity to severe flight. More than 80 percent ( n=667) of the observed goats elicited some form of behavioral stress-response, with 33 percent ( n=265) displaying a severe flight response to local rock or plant cover. Multiple regression analysis inferred goat responses to be statistically independent of the time of year, type, and vertical orientation of disturbance and group size. As expected, significant correlations ( p≤0.05) existed between distance of disturbance, geographic area, cover availability, and degree of awareness. Responses were stimulated primarily by auditory and secondarily by visual cues. Repeated aerial and ground follow-up surveys documented temporary range abandonment and changing observability indices (habitat use and activity patterns) associated with areas of intense exploration activity. The assessed data offer mitigation possibilities and enable formulation of management guidelines to lessen project impacts during future exploration, construction, and operation phases.

  15. The use of photovoltaics for rural electrification in northwestern China

    SciTech Connect

    Wallace, W.L.; Li Jingming; Gao Shangbin

    1998-09-01

    The use of renewable energy technologies in China is becoming increasingly important to meet the needs of a large rural population. Solar and wind renewable resources in particular are available in regions of China that at present have no access to conventional grid power. Two regions in China that have an acute lack of electricity are a large region in northern and western China and the coastal island region of China. These regions have attracted the attention of the Chinese government in terms of increasing the quality of life and standard of living conditions of the rural population. These regions have also attracted the attention of domestic Chinese companies and of international companies, governments, and multilateral development organizations as a potential market for renewable energy rural electrification systems. This paper focuses on the bilateral cooperation between the US Department of Energy and China in providing assistance for the use of renewable technologies for rural electrification in northwestern China.

  16. Climate Change and Neotectonic History of Northwestern China

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Chadwick, Oliver; Evans, Diane; Gillespie, Alan; Peltzer, Gilles; Tapponnier, Paul

    1996-01-01

    The progress, results and future plans for the following objectives are presented: (1) To compare the types, rates, and magnitudes of surficial modification processes that have operated in Northwest China and the Southwestern U.S.; (2) To quantify and understand the basis of the remote sensing signatures of these processes to allow extrapolation from field sites to regional maps and to allow comparisons between widely separated arid regions; (3) To use the resulting chronologies to help define the temporal and spatial distribution of continental climate changes; and (4) Determine the ages of movements on some of the active faults in Northwestern China.

  17. Ediacaran (precambrian) fossils from the wernecke mountains, northwestern Canada.

    PubMed

    Hofmann, H J; Fritz, W H; Narbonne, G M

    1983-07-29

    Fossil medusoids identified as Cyclomedusa davidi?, Beltanelliformis brunsae, and cf. Sekwia excentrica are reported from Late Precambrian strata in the Wernecke Mountains. They are representatives of the Ediacaran fauna, the oldest assemblage of cosmopolitan metazoans, and are only the third such occurrence in Canada. In addition, specimens broadly resembling the problematic structure Rugoinfractus ovruchensis, previously known only from the Precambrian of the Ukraine, are reported from the Lower Cambrian of the nearby Mackenzie Mountains.

  18. Stable Isotopic Constraints of the Turpan Basin in Northwestern China

    NASA Astrophysics Data System (ADS)

    Schaen, A. J.

    2010-12-01

    Stable isotopic analysis of sedimentary rocks can be used to reconstruct past geologic changes in the elevation and climate of topographic features such as mountain ranges and plateaus. The Tibetan Plateau is an ideal field laboratory for conducting this type of study because of the Plateau’s extreme topographic relief and relatively recent geologic growth. Here we present oxygen and carbon isotope compositions from a suite of sedimentary rock samples taken from the western Turpan Basin in northwestern China. This area of the basin collects sediment from weathering and erosion of the Bogda Shan located to the north. The goal of this study is to analyze changes in the stable isotope composition as a function of stratigraphic position to reconstruct paleoelevations and paleoclimates in this part of the Tibetan Plateau. The sedimentary rock samples analyzed in this study are Late Jurassic to Neogene age and are primarily mudstone, siltstone, fine sandstone along with lesser limestone. Samples were powered and then dissolved with phosphoric acid at 72οC. The liberated CO2 gas was then analyzed using a Finnigan Delta Plus XL mass spectrometer with a gasbench inlet system. Oxygen isotope values range from -13.72 to -1.62‰ (PDB) and exhibit a large scale trend to more negative values toward the top of the stratigraphic sequence. Superimposed on this large scale trend are systematic variations in isotopic composition as a function of age. The most positive δ18O values occur at approximately 160, 115, 60, and 5 ma. Conversely, δ18O minima are observed at 150, 90, and 40 ma. δ13C values range from -10.69‰ to 1.40‰ (PDB). The most positive δ13C values (-4.3 to 1.4) occur from 120-160 ma. Younger samples display small scale variations with age with notable δ13C minima of -10.7, -14.7, and -7.6‰ at 108, 80, and 17 ma, respectively. The variable δ18O and positive δ13C values from the Jurassic (145-160 ma) are consistent with an arid climate and high atmospheric

  19. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology

    NASA Astrophysics Data System (ADS)

    Li, Jiyan; Dong, Zhibao; Qian, Guangqiang; Zhang, Zhengcai; Luo, Wanyin; Lu, Junfeng; Wang, Meng

    2016-03-01

    The northwestern Qaidam Basin exposes one of the largest and highest elevation yardang fields on Earth. The aim of the present study was to describe the distribution and morphology of these yardangs, and analyze the factors responsible for the distribution pattern of these aeolian landforms. The yardang fields are bounded by piedmont alluvial-diluvial fans from the mountain ranges surrounding the basin, except in the south, where they are bounded by dune fields, dry salt flats, lakes, and rivers. This distribution pattern can be attributed to regional tectogenesis and its corresponding environmental impacts. The morphology of the yardangs varies considerably in response to the diverse factors that control their formation and evolution. Long-ridge yardangs are mainly located in the northernmost part of the yardang field, and the long ridges are gradually dissected into smaller ridges in the downwind direction. Further downwind, the convergence of northerly and northwesterly winds and the effects of temporary runoff cause the ridges to gradually transition into mesa yardangs. Saw-toothed crests, and conical and pyramidal yardangs, occur in groups on folded brachyanticlinal structures. Typical whaleback yardangs are found in the southeast, at the northern margin of Dabuxun Lake. Morphological parameters vary among the yardang types. The orientation of the yardangs in the northernmost area is nearly N-S, with a transition towards NW-SE in the southernmost area in response to a change in the dominant wind direction that results from the orientations and positions of the mountain ranges that surround the basin.

  20. Himalayan Mountain Range, India/China

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The frontier between India (Kashmir) and China (Tibet) (33.5N, 79.5E) lies across the narrow land bridge between the two lakes near the center of this photo. Many of the peaks in this region of the Karakoram and Latakh ranges of the Himalayan Mountains, exceed 20,000 ft. making it one of the most remote regions of the Earth. The large end lake is the Kako in China and the long narrow lake is the Pangong in India.

  1. Summer moisture variations in northwestern China during the past 700 years

    NASA Astrophysics Data System (ADS)

    Long, Z.; Feng, S.; Zhang, Y.

    2014-12-01

    The northwestern China is one of the most arid regions in the middle latitudes, where water is scarce year round. This study investigated the variations of summer moisture in this region using Palmer Drought Severity Index (PDSI) derived from instrumental data and tree-ring records. Based on rotational Empirical Orthogonal Function (REOF) analysis, the observed summer moisture variations in northwestern China can be classified into three major patterns: the south Xinjing, north Xinjing and eastern parts of the northwestern China. The areal-averaged PDSI in south Xinjing is steading increasing while the PDSI in the eastern parts of the northwestern China is steading decreasing since 1951. The PDSI in north Xinjing, however, was decreasing before middle 1970s followed by abrupt increasing in recent three decades. The tree-ring reconstructed PDSI (MADA) replicates the three major moisture patterns, and has been used to search possible paleo-analogs during the past 700 years. The observed multi-year droughts in south Xinjing occurred 10 times since 1300AD. The spatial distribution of those droughts show extended dry conditions in northwestern China and stretched southeastward to cover the middle and lower Youngtze River Valley. The droughts associated with north Xinjing pattern are more local, mostly confined in north Xinjiang and neighboring regions. The droughts that affected the eastern parts of the northwestern China also affected majority of the eastern China. Overall, there are no noticeable changes in the drought intensity and duration in south and north Xinjing during the past 700 years. However, the modern droughts in the east parts of the northwestern China are much stronger than that during the historical time. The recent drought during 1995-2005 in this region was the most severe during the past 700 years.

  2. Structural development and oil occurrence on northeast flank of Uinta Mountains near Irish Canyon, northwestern Colorado

    SciTech Connect

    Roehler, H.W.

    1985-05-01

    The study area is located along Vermillion Creek, 1-3 mi (1.6-5 km) east of Irish Canyon, in northwestern Colorado. The exposed stratigraphic section consists of steeply dipping to vertical Upper Cretaceous Almond Formation, Ericson, Sandstone, and Mancos Shale along the toe of the Sparks Ranch thrust fault, and of lesser dipping older Mesozoic and Paleozoic formations in distant parts of the thrust plate. In most places, the Almond Formation is in contact across the thrust fault with the Eocene Wasatch and Green River Formations, and all of these formations are unconformably overlain by the Oligocene Bishop Conglomerate and the Miocene Browns Park Formation. The structural development of the area has involved three major events: (1) Late Cretaceous uplift of the Uinta Mountains; (2) Paleocene and Eocene thrust movements of the sparks Ranch fault; and (3) late Tertiary normal faulting associated with a collapse of the eastern Uinta Mountains. Oil-saturated sandstones are present in outcrops of 10 Paleozoic, Mesozoic, and Tertiary formations adjacent to several of the late Tertiary normal faults. Oil is escaping to the surface along these faults, probably from a large, deep-seated reservoir located below the Sparks Ranch thrust fault.

  3. Regional significance of Mississippian rocks at Pentagon Mountain, Lewis and Clark Range, northwestern Montana

    SciTech Connect

    Nichols, K.M.

    1985-05-01

    Pentagon Mountain exposes one of the best of the few sections of Mississippian rocks in the Lewis and Clark Range of northwestern Montana. This section consists of 225 m (738 ft) of marine carbonate rocks from which conodonts, ranging in age from earliest Osagean to early Meramecian, have been identified. Its stratigraphic base is well exposed, but the top has been eroded. Five units are recognized in this sequence, in ascending order: (1) phosphatized coarsely crinoidal and spiculitic wackestone, (2) dolomitic lime mudstone or wackestone, thinly interbedded with spiculitic biogenic chert, (3) partly dolomitized lime bioclastic wackestone showing much pressure-solution compaction, (4) partly dolomitized lime bioclastic packstone or wackestone, also showing much pressure-solution compaction, and (5) dolomitic mudstone. The Mississippian sequence at Pentagon Mountain can be readily correlated lithologically, across the Lewis thrust system with Mississippian rocks that crop out to the east in the Sawtooth Range. This implies either that Mississippian units were originally widespread or that the magnitude of thrusting between the Mississippian rocks in the Lewis and Clark Range and those in the Sawtooth Range was insignificant. However, Mississippian rocks at Pentagon Mountain exhibit extreme pressure-solution compaction, which suggests greater stratigraphic or structural burial of these rocks than their Mississippian counterparts in the Sawtooth Range. Secondary dolomite is pervasive in the lower part of the Mississippian section in the Lewis and Clark Range, and spectacular solution breccias locally disrupt the base of the section. These breccias and the adjacent dolomite are probably related, as both are thought to result from the passage of fluids through these rocks during Laramide uplift and/or post Laramide erosion and extension.

  4. High diversity of nitrogen-fixing bacteria in upper reaches of Heihe River, Northwestern China

    NASA Astrophysics Data System (ADS)

    Tai, X. S.; Mao, W. L.; Liu, G. X.; Chen, T.; Zhang, W.; Wu, X. K.; Long, H. Z.; Zhang, B. G.

    2013-03-01

    Vegetation plays a key role to water conservation in southern Qilian Mountains (Northwestern China), the upper reaches of Heihe River. Nitrogen-fixing bacteria are crucial for vegetation protection because they can supply plants with nitrogen source. Nevertheless, little is known about nitrogen-fixing bacteria in this region. In present study, nifH gene clone libraries were established for detecting the difference of nitrogen-fixing bacterial communities between Potentilla parvifolia shrub and Carex alrofusca meadow in the southern Qilian Mountains. All the identified nitrogen-fixing bacterial clones belonged to Proteobacteria. At the genus level, the Azospirillum sp. was only detected in shrub soil while Thiocapsa sp., Derxiasp., Ectothiorhodospira sp., Mesorhizobium sp., Klebsiella sp., Ensifer sp., Methylocella sp. and Peseudomonas sp. were just detected in meadow soil. Shannon-Wiener index of nifH gene ranged from 1.5 to 2.8 and was higher in meadow soil than shrub soil. Contrarily, the nifH gene copies and CFUs of cultured nitrogen-fixing bacteria ranged from 0.4 × 107 to 6.9 × 107 copies g-1 soil and 0.97 × 106 to 12.78 × 106 g-1 soil, respectively. Furthermore, both of them were lower in meadow soil than shrub soil. Statistical analysis revealed that diversity and copies of nifH gene mostly correlated with aboveground biomass in shrub soil. In meadow soil, nifH gene diversity was principally affected by altitude while copies did by soil available K.

  5. Crustal structure across the Xisha Trough, northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Qiu, Xuelin; Ye, Sanyu; Wu, Shimin; Shi, Xiaobin; Zhou, Di; Xia, Kanyuan; Flueh, Ernst R.

    2001-11-01

    Located at the northwestern part of the South China Sea (SCS) between the Hainan and Xisha (Paracel) Islands, the Xisha Trough represents a failed rift in conjunction with the opening of the SCS between 32 and 17 Ma. From west towards east within a scale of several hundred kilometers, it presents all major stages of the rifting process, and thus, provides an ideal place to study the rifting process in great details. In the autumn of 1996, a joint team of Sino-German scientists carried out a wide-angle seismic experiment across the Xisha Trough with 10 ocean bottom hydrophones (OBH) along a 237-km NNW-SSE-oriented profile, which was surveyed in 1987 with multi-channel seismic (MCS) method by BGR of Germany and SOA of China. Favorable weather conditions and the powerful 4×12-l air gun array rendered very good quality data with seismic signals observed at the offset of up to 110 km. A detailed velocity-depth model was obtained by using an interactive trial-and-error 2D ray-tracing method. Interpretation of the MCS data published by BGR provides very good geometrical constraints of the complex upper crustal structure, which is characterized by fault blocks, half-horsts and half-grabens filled with syn- and post-rift Cenozoic sediments. The velocity model in turn confirms the major structure outlined by the interpretation of the MCS data, showing a varying sedimentary layer between 1 and 4 km of thickness and velocities between 1.7 and 4.5 km/s. The P-wave velocity of 5.5 km/s on the top of the crystalline basement is relatively low, suggesting strong weathering. Within the crystalline crust, the velocity increases downward continuously to 6.8 km/s at the bottom of the crust without a clear differentiation in the middle crust, showing clearly its continental nature even beneath the Xisha Trough. The Moho is marked by a sharp first-order interface with a velocity of 8.0-8.1 km/s at the uppermost mantle. The Moho depth is 15 km beneath the center of the trough and

  6. Greater sage-grouse nest predators in the Virginia Mountains of northwestern Nevada

    USGS Publications Warehouse

    Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

    2013-01-01

    Greater sage-grouse Centrocercus urophasianus, hereafter sage-grouse, populations have declined across their range due to the loss, degradation, and fragmentation of habitat. Habitat alterations can lead not only to vegetative changes but also to shifts in animal behavior and predator composition that may influence population vital rates, such as nest success. For example, common ravens Corvus corax are sage-grouse nest predators, and common raven abundance is positively associated with human-caused habitat alterations. Because nest success is a central component to sage-grouse population persistence, research that identifies factors influencing nest success will better inform conservation efforts. We used videography to unequivocally identify sage-grouse nest predators within the Virginia Mountains of northwestern Nevada, USA, from 2009 to 2011 and used maximum likelihood to calculate daily probability of nest survival. In the Virginia Mountains, fires, energy exploration, and other anthropogenic activities have altered historic sage-grouse habitat. We monitored 71 sage-grouse nests during the study, placing video cameras at 39 nests. Cumulative nest survival for all nests was 22.4% (95% CI, 13.0–33.4%), a survival rate that was significantly lower than other published results for sage-grouse in the Great Basin. Depredation was the primary cause for nest failure in our study (82.5%), and common ravens were the most frequent sage-grouse nest predator, accounting for 46.7% of nest depredations. We also successfully documented a suite of mammalian and reptilian species depredating sage-grouse nests, including some predators never previously confirmed in the literature to be sage-grouse nest predators (i.e., bobcats Lynx rufus and long-tailed weasels Mephitis frenata). Within the high elevation, disturbed habitat of the Virginia Mountains, low sage-grouse nest success may be limiting sage-grouse population growth. These results suggest that management actions that

  7. Pedogenesis and Permafrost Carbon Over the Eboling Ridge in Heihe River Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Mu, C.; Zhang, T.; Cao, B.; Wang, Q.; Peng, X.; Cheng, G.

    2013-12-01

    Based on field permafrost sampling and laboratory analysis, we found that the average storages of soil organic carbon (SOC), total nitrogen (TN) and soil inorganic carbon (SIC) in permafrost soils were much more than that in the active layer on the Eboling Mountain in the upper reach of Heihe River basin, northwestern China. The objective of this study is to better understand the main soil physicochemical parameters influencing C and N dynamics in permafrost regions of northwestern China. Specifically, we investigated the effect of pedogenesis, cryogenic structure and SIC on SOC, TN and water-soluble organic carbon (WSOC) in the permafrost regions. The preliminary results show that SIC is a significant factor influencing carbon flux between atmosphere and terrestrial ecosystem and the distribution patterns of SOC and N. There are high correlation between SIC, SOC and N in permafrost. SOC and SIC can interact with each other, their small change may radically alter the carbon balance. SIC as a major factor will be crucial for developing large scale models evaluating C and N dynamics. High contents of C and N combined with a low vertical variability in each horizon on the Eboling Mountain can be explained by longer duration of pedogenesis and the influence of permafrost. In permafrost regions, the vertical distribution of soil C and N is also influenced by soil cryogenic structure. The high content of WSOC in deep permafrost soils can be explained by the formation of the ground ice causes the WSOC enrichment followed moisture migration. The average WSOC content in permafrost soils was larger than that in the active layer, suggesting that the labile carbon in permafrost soils has higher quality. SIC can reflect the microbial activity indirectly, due to the good negative relationship between SIC, soil pH and C/N ratios in permafrost. Soil pH values were the important factor influencing the distribution of SIC in deep permafrost soils. SIC in permafrost soils was

  8. Preliminary analysis of Greater Sage-grouse reproduction in the Virginia Mountains of northwestern Nevada

    USGS Publications Warehouse

    Coates, Peter S.; Lockyer, Zachary B.; Farinha, Melissa A.; Sweeney, Joelle M.; Johnson, Valerie M.; Meshriy, Matthew G.; Espinosa, Shawn P.; Delehanty, David J.; Casazza, Michael L.

    2011-01-01

    Relationships between habitat selection and population vital rates of greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse), recently designated as a candidate species under the Endangered Species Act, within the Great Basin are not well-understood. The growing development of renewable energy infrastructure within areas inhabited by sage-grouse is thought to influence predator and vegetation communities. For example, common ravens (Corvus corax), a synanthropic sage-grouse nest predator, are increasing range-wide and select transmission lines and other tall structures for nesting and perching. In the Virginia Mountains of northwestern Nevada, we collected preliminary information of space-use, habitat selection, and population vital rates during the nesting and brood-rearing period over two years on 56 sage-grouse. Additionally, videography at nest sites (n = 22) was used to identify sage-grouse nest predators. The study area is a potential site for renewable energy developments (i.e., wind and solar), and we plan to continue monitoring this population using a before-after-control-impact study design. The results reported here are preliminary and further data are required before conclusions can be drawn from this population of sage-grouse.

  9. Clastic dikes of Heart Mountain fault breccia, northwestern Wyoming, and their significance

    USGS Publications Warehouse

    Pierce, W.G.

    1979-01-01

    Structural features in northwestern Wyoming indicate that the Heart Mountain fault movement was an extremely rapid, cataclysmic event that created a large volume of carbonate fault breccia derived entirely from the lower part of the upper plate. After fault movement had ceased, much of the carbonate fault breccia, here called calcibreccia, lay loose on the resulting surface of tectonic denudation. Before this unconsolidated calcibreccia could be removed by erosion, it was buried beneath a cover of Tertiary volcanic rocks: the Wapiti Formation, composed of volcanic breccia, poorly sorted volcanic breccia mudflows, and lava flows, and clearly shown in many places by inter lensing and intermixing of the calcibreccia with basal volcanic rocks. As the weight of volcanic overburden increased, the unstable water-saturated calcibreccia became mobile and semifluid and was injected upward as dikes into the overlying volcanic rocks and to a lesser extent into rocks of the upper plate. In some places the lowermost part of the volcanic overburden appears to have flowed with the calcibreccia to form dike like bodies of mixed volcanic rock and calcibreccia. One calcibreccia dike even contains carbonized wood, presumably incorporated into unconsolidated calcibreccia on the surface of tectonic denudation and covered by volcanic rocks before moving upward with the dike. Angular xenoliths of Precambrian rocks, enclosed in another calcibreccia dike and in an adjoining dikelike mass of volcanic rock as well, are believed to have been torn from the walls of a vent and incorporated into the basal part of the Wapiti Formation overlying the clastic carbonate rock on the fault surface. Subsequently, some of these xenoliths were incorporated into the calcibreccia during the process of dike intrusion. Throughout the Heart Mountain fault area, the basal part of the upper-plate blocks or masses are brecciated, irrespective of the size of the blocks, more intensely at the base and in places

  10. Education, Employment and Empowerment: The Case of a Young Woman in Northwestern China

    ERIC Educational Resources Information Center

    Maslak, Mary Ann

    2011-01-01

    As a marginalized region of the world, the rural Gansu Province of northwestern China provides an informative canvas on which to examine and understand the ways in which education contributes to the lives of local Muslim women and supports their goals for work. Specifically, this article highlights the role education plays in the life of one young…

  11. Canopy storage capacity of xerophytic shrubs in Northwestern China

    NASA Astrophysics Data System (ADS)

    Wang, Xin-ping; Zhang, Ya-feng; Hu, Rui; Pan, Yan-xia; Berndtsson, Ronny

    2012-08-01

    SummaryThe capacity of shrub canopy water storage is a key factor in controlling the rainfall interception. Thus, it affects a variety of hydrological processes in water-limited arid desert ecosystems. Vast areas of revegetated desert ecosystems in Northwestern China are occupied by shrub and dwarf shrub communities. Yet, data are still scarce regarding their rainwater storage capacity. In this study, simulated rainfall tests were conducted in controlled conditions for three dominant xerophytic shrub types in the arid Tengger Desert. Eight rainfall intensities varying from 1.15 to 11.53 mm h-1 were used to determine the canopy water storage capacity. The simulated rainfall intensities were selected according to the long-term rainfall records in the study area. The results indicate that canopy storage capacity (expressed in water storage per leaf area, canopy projection area, biomass, and volume of shrub respectively) increased exponentially with increase in rainfall intensity for the selected shrubs. Linear relationships were found between canopy storage capacity and leaf area (LA) or leaf area index (LAI), although there was a striking difference in correlation between storage capacity and LA or LAI of Artemisia ordosica compared to Caragana korshinskii and Hedysarum scoparium. This is a result of differences in biometric characteristics, especially canopy morphology between the shrub species. Pearson correlation coefficient indicated that LA and dry biomass are better predictors as compared to canopy projection area and volume of samples for precise estimation of canopy water storage capacity. In terms of unit leaf area, mean storage capacity was 0.39 mm (range of 0.24-0.53 mm), 0.43 mm (range of 0.28-0.60 mm), and 0.61 mm (range of 0.29-0.89 mm) for C. korshinskii, H. scoparium, and A. ordosica, respectively. Correspondingly, divided per unit dry biomass, mean storage capacity was 0.51 g g-1 (range of 0.30-0.70 g g-1), 0.41 g g-1 (range of 0.26-0.57 g g-1), and

  12. Structural and stratigraphic mapping from satellite imagery, Kalpin uplift, northwestern Tarim basin, northwest China

    SciTech Connect

    McKnight, C.L.; Carroll, A.R.; Chu, J.; Hendrix, M.S.; Graham, S.A.; Lyon, R.J.P. )

    1990-05-01

    The Kalpin uplift, located on the northwestern margin of the Tarim craton, northwest China, exposes a complete Paleozoic cratonal stratigraphic sequence. The lack of vegetative cover and the visible color contrasts between stratigraphic units afford an optimal situation for detailed geologic mapping from Landsat Multispectral Scanner imagery at a scale of 1:250,000. Field work in the eastern Kalpin uplift constrains the geologic interpretation of the satellite imagery. Exposed basement rock in the Kalpin uplift consists of deformed and metamorphosed upper Proterozoic strata cut by unmetamorphosed mafic dikes. The overlying sedimentary section was deposited primarily in shallow marine to nonmarine environments and includes Sinian (latest Proterozoic to early Cambrian) siliciclastics and carbonates; Cambrian and Ordovician carbonates; Silurian green shales; Devonian red beds; Carboniferous siliciclastics and carbonates; and Permian carbonates, siliciclastics, and subaerial basalt flows. Paleozoic strata are exposed in a series of low, parallel, curvilinear ranges located at the leading edges of low-angle, southeast-vergent thrust sheets. The regular thrust repetition of the entire Paleozoic section suggests the presence of a detachment horizon within the Cambrian section. These southeast-vergent thrust sheets override an older structural trend on the craton, the Bachu uplift, at right angles, folding as they do so. Strike-slip faults cutting the thrust sheets along the same trend as the Bachu uplift suggest the location of buried lateral ramps associated with the Bachu uplift. The young deformation in the Kalpin uplift is a response to compressive stresses produced by the northward movement of the Indian plate. Major faults in the Tian Shan mountain range to the north have been reactivated, resulting in southward-directed thrusting over the Tarim craton.

  13. Linking land cover dynamics with driving forces in mountain landscape of the Northwestern Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Regos, Adrián; Ninyerola, Miquel; Moré, Gerard; Pons, Xavier

    2015-06-01

    The mountainous areas of the northwestern Iberian Peninsula have undergone intense land abandonment. In this work, we wanted to determine if the abandonment of the rural areas was the main driver of landscape dynamics in Gerês-Xurés Transboundary Biosphere Reserve (NW Iberian Peninsula), or if other factors, such as wildfires and the land management were also directly affecting these spatio-temporal dynamics. For this purpose, we used earth observation data acquired from Landsat TM and ETM + satellite sensors, complemented by ancillary data and prior field knowledge, to evaluate the land use/land cover changes in our study region over a 10-year period (2000-2010). The images were radiometrically calibrated using a digital elevation model to avoid cast- and self-shadows and different illumination effects caused by the intense topographic variations in the study area. We applied a maximum likelihood classifier, as well as other five approaches that provided insights into the comparison of thematic maps. To describe the land cover changes we addressed the analysis from a multilevel approach in three areas with different regimes of environmental protection. The possible impact of wildfires was assessed from statistical and spatially explicit fire data. Our findings suggest that land abandonment and forestry activities are the main factors causing the changes in landscape patterns. Specifically, we found a strong decrease of the 'meadows and crops' and 'sparse vegetation areas' in favor of woodlands and scrublands. In addition, the huge impact of wildfires on the Portuguese side have generated new 'rocky areas', while on the Spanish side its impact does not seem to have been a decisive factor on the landscape dynamics in recent years. We conclude rural exodus of the last century, differences in land management and fire suppression policies between the two countries and the different protection schemes could partly explain the different patterns of changes recorded in

  14. Impact of Reforestation on Local Climate and Environment in a Semi-arid Urban Valley, Northwestern China

    NASA Astrophysics Data System (ADS)

    Xia, D.; Yu, Y.; He, J.

    2015-12-01

    Since 1999 Chinese government has invested more than 800 million Yuan to reforest the southern and the northern mountains surrounding urban Lanzhou - a typical semi-arid city located in a river valley, Northwestern China. Until 2009 obvious land use change occurred, with 69.2% of the reforested area been changed from grasslands, croplands, barren or sparsely vegetated land to closed shrublands and 20.6% been changed from closed shrublands, grasslands, and croplands to forests. This study assesses the impact of these changes on local climate and environment in winter using WRF (Weather Research & Forecasting) model incorporated with high-resolution remotely sensed land cover data for 1999 and 2009 and the FLEXible PARTicle (FLEXPART) dispersion model. Results indicate that the changes in albedo, surface exchange coefficient and surface soil heat conductivity related to the reforestation led to the changes in surface net radiation and the surface energy partitioning, which in turn affected the meteorology fields and enhanced the mountain-valley wind circulation. The amount of air exchanged between the valley and the outside increased after reforestation during the day, with the largest increase of 10 %, while it changed little during the night on winter sunny day with no snow cover. The sensitivity analysis using FLEXPART-WRF model indicates that the reforestation affected the spatial distribution of pollutants and slightly improved the urban air quality in winter. And the greening program of Lanzhou has special reference to other valley urbans.

  15. Anthropogenic Air Pollution Observed Near Dust Source Regions in Northwestern China During Springtime 2008

    NASA Technical Reports Server (NTRS)

    Li, Can; Tsay, Si-Chee; Fu, Joshua S.; Dickerson, Russell R.; Ji, Qiang; Bell, Shaun W.; Gao, Yang; Zhang, Wu; Huang, Jianping; Li, Zhanqing; Chen, Hongbin

    2010-01-01

    Trace gases and aerosols were measured in Zhangye (39.082degN, 100.276degE, 1460 m a.s. 1.), a rural site near the Gobi deserts in northwestern China during spring 2008. Primary trace gases (CO:265 ppb; SO2:3.4 ppb; NO(*y): 4.2 ppb; hereafter results given as means of hourly data) in the area were lower than in eastern China, but still indicative of marked anthropogenic emissions. Sizable aerosol mass concentration (153 micro-g/cu m) and light scattering (159/Mm at 500 nm) were largely attributable to dust emissions, and aerosol light absorption (10.3/Mm at 500 nm) was dominated by anthropogenic pollution. Distinct diurnal variations in meteorology and pollution were induced by the local valley terrain. Strong daytime northwest valley wind cleaned out pollution and was replaced by southeast mountain wind that allowed pollutants to build up overnight. In the afternoon, aerosols had single scattering albedo (SSA, 500 mn) of 0.95 and were mainly of supermicron particles, presumably dust, while at night smaller particles and SSA of 0.89-0.91 were related to Pollution. The diverse local emission sources were characterized: the CO/SO2, CO/NO(y), NO(y)/SO2 (by moles), and BC/CO (by mass) ratios for small point sources such as factories were 24.6-54.2, 25.8-35.9, 0.79-1.31, and 4.1-6.1 x 10(exp -3), respectively, compared to the corresponding inventory ratios of 43.7-71.9, 23.7-25.7, 1.84-2.79, and 3.4-4.0 x 10(exp -3) for the industrial sector in the area. The mixing between dust and pollution can be ubiquitous in this region. During a dust storm shown as an example, pollutants were observed to mix with dust, causing discernible changes in both SSA and aerosol size distribution. Further interaction between dust and pollutants during transport may modify the properties of dust particles that are critical for their large-scale impact on radiation, clouds, and global biogeochemical cycles.

  16. Anthropogenic air pollution observed near dust source regions in northwestern China during springtime 2008

    NASA Astrophysics Data System (ADS)

    Li, Can; Tsay, Si-Chee; Fu, Joshua S.; Dickerson, Russell R.; Ji, Qiang; Bell, Shaun W.; Gao, Yang; Zhang, Wu; Huang, Jianping; Li, Zhanqing; Chen, Hongbin

    2010-04-01

    Trace gases and aerosols were measured in Zhangye (39.082°N, 100.276°E, 1460 m a.s.l.), a rural site near the Gobi deserts in northwestern China during spring 2008. Primary trace gases (CO: 265 ppb; SO2: 3.4 ppb; NOy*: 4.2 ppb; hereafter results given as means of hourly data) in the area were lower than in eastern China, but still indicative of marked anthropogenic emissions. Sizable aerosol mass concentration (153 μg/m3) and light scattering (159 Mm-1 at 500 nm) were largely attributable to dust emissions, and aerosol light absorption (10.3 Mm-1 at 500 nm) was dominated by anthropogenic pollution. Distinct diurnal variations in meteorology and pollution were induced by the local valley terrain. Strong daytime northwest valley wind cleaned out pollution and was replaced by southeast mountain wind that allowed pollutants to build up overnight. In the afternoon, aerosols had single scattering albedo (SSA, 500 nm) of 0.95 and were mainly of supermicron particles, presumably dust, while at night smaller particles and SSA of 0.89-0.91 were related to pollution. The diverse local emission sources were characterized: the CO/SO2, CO/NOy, NOy/SO2 (by moles), and BC/CO (by mass) ratios for small point sources such as factories were 24.6-54.2, 25.8-35.9, 0.79-1.31, and 4.1-6.1 × 10-3, respectively, compared to the corresponding inventory ratios of 43.7-71.9, 23.7-25.7, 1.84-2.79, and 3.4-4.0 × 10-3 for the industrial sector in the area. The mixing between dust and pollution can be ubiquitous in this region. During a dust storm shown as an example, pollutants were observed to mix with dust, causing discernible changes in both SSA and aerosol size distribution. Further interaction between dust and pollutants during transport may modify the properties of dust particles that are critical for their large-scale impact on radiation, clouds, and global biogeochemical cycles.

  17. Geomorphic Processes and Remote Sensing Signatures of Alluvial Fans in the Kun Lun Mountains, China

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Chadwick, Oliver A.

    1996-01-01

    The timing of alluvial deposition in arid and semiarid areas is tied to land-surface instability caused by regional climate changes. The distribution pattern of dated deposits provides maps of regional land-surface response to past climate change. Sensitivity to differences in surface roughness and composition makes remote sensing techniques useful for regional mapping of alluvial deposits. Radar images from the Spaceborne Radar Laboratory and visible wavelength images from the French SPOT satellite were used to determine remote sensing signatures of alluvial fan units for an area in the Kun Lun Mountains of northwestern China. These data were combined with field observations to compare surface processes and their effects on remote sensing signatures in northwestern China and the southwestern United States. Geomorphic processes affecting alluvial fans in the two areas include aeolian deposition, desert varnish, and fluvial dissection. However, salt weathering is a much more important process in the Kun Lun than in the southwestern United States. This slows the formation of desert varnish and prevents desert pavement from forming. Thus the Kun Lun signatures are characteristic of the dominance of salt weathering, while signatures from the southwestern United States are characteristic of the dominance of desert varnish and pavement processes. Remote sensing signatures are consistent enough in these two regions to be used for mapping fan units over large areas.

  18. Long-term regional precipitation disparity in northwestern China and its driving forces

    NASA Astrophysics Data System (ADS)

    Lee, H. F.; Pei, Q.; Zhang, D. D.; Choi, K. P. K.

    2014-08-01

    Subject to the unique physical setting of northwestern China (NW China), precipitation in the region is characterized by salient regional differences. Yet, the long-term regional precipitation disparity in NW China still remains insufficiently-explored. In the present study, we base on historical documentation to reconstruct the precipitation indices of two macro regions in NW China between AD580-1979 to address the following issues: (1) determine the multi-decadal to centennial regional precipitation disparity in NW China, a topic which has not been systematically examined in previous paleo-climate/paleo-environment studies; and (2) find the major driving forces behind it. Wavelet analysis, which is ideal for analyzing non-stationary systems, is applied. Our results show that there is significant regional discrepancy of precipitation change in NW China over extended period. Although there is significant association between the regional precipitation disparity in NW China and various modes of atmospheric circulation, the association is characterized by a regime shift during the transition from the Medieval Warm Period to the Little Ice Age. Most importantly, the low-frequency cycle of the El Niño-Southern Oscillation is found to be the most prominent pacemaker of regional precipitation disparity in NW China at the multi-decadal to centennial timescales. Our findings help to demonstrate which atmospheric circulation is primarily responsible for the long-term regional precipitation disparity in NW China, which may have important implications for water resource management in NW China in the near future.

  19. Analogous Study of the Linguistic Knowledge between Monolingual and Bilingual Students in the Minority Region of Northwestern China

    ERIC Educational Resources Information Center

    He, Hao

    2008-01-01

    Minority students' English learning is a special and an indispensable component of English education system in China. This article studies students' linguistic knowledge that live in Northwestern China--Gan Nan Autonomy State of Gan Su Province with majority population of Tibetan, mixed with Chinese and some Muslim. An analogous analysis is…

  20. Tree ring density-based summer temperature reconstruction for the central Hengduan Mountains in southern China

    NASA Astrophysics Data System (ADS)

    Fan, Ze-Xin; Bräuning, Achim; Yang, Bao; Cao, Kun-Fang

    2009-01-01

    Variations in ring width and wood density of Picea brachytyla were used to develop high-resolution climate proxy data to extend the existing climate record in the central Hengduan Mountains, north-western Yunnan Province, China. Growth-climate response analyses showed that the total ring width (TRW) and maximum latewood density (MXD) in the sub-alpine zone are mainly influenced by summer temperature variability. Based on a MXD regional chronology derived from two high elevation sites, we developed a warm season (April-September) temperature reconstruction for the period A.D. 1750-2006. The climate/tree-growth model accounts for 41% of the instrumental temperature variance during the period 1958-2004. Warm summers occurred during 1750s, 1820-50s, 1880-1890s, 1930-1950s and 1990-present; while the periods of 1790-1810s, 1860-1870s, 1900-1920s, and 1960-1985 were relatively cold. Spatial climate correlation analyses with gridded land surface data revealed that our warm season temperature reconstruction contains a strong regional temperature signal for the Hengduan Mountain ranges. Our reconstruction successfully captured recent abrupt climatic changes and agreed in general with other tree ring-based temperature reconstructions from nearby regions on a decadal timescale. In addition, reconstructed summer temperature variations were consistent with recorded glacier fluctuations in the surrounding high mountains.

  1. Crustal structure and extension mode in the northwestern margin of the South China Sea

    NASA Astrophysics Data System (ADS)

    Gao, Jinwei; Wu, Shiguo; McIntosh, Kirk; Mi, Lijun; Liu, Zheng; Spence, George

    2016-06-01

    Combining multi-channel seismic reflection and gravity modeling, this study has investigated the crustal structure of the northwestern South China Sea margin. These data constrain a hyper-extended crustal area bounded by basin-bounding faults corresponding to an aborted rift below the Xisha Trough with a subparallel fossil ridge in the adjacent Northwest Sub-basin. The thinnest crust is located in the Xisha Trough, where it is remnant lower crust with a thickness of less than 3 km. Gravity modeling also revealed a hyper-extended crust across the Xisha Trough. The postrift magmatism is well developed and more active in the Xisha Trough and farther southeast than on the northwestern continental margin of the South China Sea; and the magmatic intrusion/extrusion was relatively active during the rifting of Xisha Trough and the Northwest Sub-basin. A narrow continent-ocean transition zone with a width of ˜65 km bounded seaward by a volcanic buried seamount is characterized by crustal thinning, rift depression, low gravity anomaly and the termination of the break-up unconformity seismic reflection. The aborted rift near the continental margin means that there may be no obvious detachment fault like that in the Iberia-Newfoundland type margin. The symmetric rift, extreme hyper-extended continental crust and hotter mantle materials indicate that continental crust underwent stretching phase (pure-shear deformation), thinning phase and breakup followed by onset of seafloor spreading and the mantle-lithosphere may break up before crustal-necking in the northwestern South China Sea margin.

  2. A View from the Mountain Top: The Purple Mountain Observatory Library, China

    ERIC Educational Resources Information Center

    Zhang, Jian

    2012-01-01

    This paper discusses the author's experience directing the Purple Mountain Observatory Library, Chinese Academy of Sciences (CAS) in Nanjing, China. Routine collection development, management and preservation issues are described, and the unique challenges and opportunities involved in operating a remote observatory library are highlighted.

  3. The rural carbonaceous aerosols in coarse, fine, and ultrafine particles during haze pollution in northwestern China.

    PubMed

    Zhu, Chong-Shu; Cao, Jun-Ji; Tsai, Chuen-Jinn; Shen, Zhen-Xing; Liu, Sui-Xin; Huang, Ru-Jin; Zhang, Ning-ning; Wang, Ping

    2016-03-01

    The carbonaceous aerosol concentrations in coarse particle (PM10: Dp ≤ 10 μm, particulate matter with an aerodynamic diameter less than 10 μm), fine particle (PM2.5: Dp ≤ 2.5 μm), and ultrafine particle (PM0.133: Dp ≤ 0.133 μm) carbon fractions in a rural area were investigated during haze events in northwestern China. The results indicated that PM2.5 contributed a large fraction in PM10. OC (organic carbon) accounted for 33, 41, and 62 % of PM10, PM2.5, and PM0.133, and those were 2, 2.4, and 0.4 % for EC (elemental carbon) in a rural area, respectively. OC3 was more abundant than other organic carbon fractions in three PMs, and char dominated EC in PM10 and PM2.5 while soot dominated EC in PM0.133. The present study inferred that K(+), OP, and OC3 are good biomass burning tracers for rural PM10 and PM2.5, but not for PM0.133 during haze pollution. Our results suggest that biomass burning is likely to be an important contributor to rural PMs in northwestern China. It is necessary to establish biomass burning control policies for the mitigation of severe haze pollution in a rural area.

  4. Dust Storm Reduction due to Precipitation and Temperature Enhancement in Northwestern China: A Direct Climatic Impact of Absorbing Aerosols

    NASA Astrophysics Data System (ADS)

    Gu, Y.; Liou, K.; Chen, W.; Liao, H.

    2009-12-01

    Dust storms originating in the Gobi desert and northwestern China critically impact weather, climate, and public health in China and neighboring Pacific Rim countries. The frequent occurrence of dust storms has been attributed to both deforestation and the changing environment. Dust storm formation is determined by a number of factors, including dryness, wind field, soil type, and precipitation, with precipitation being the most essential factor. Dust storms normally originate in northwestern China where annual precipitation is less than 400 mm, particularly in extremely dry areas (less than 200 mm), including the Taklamakan Desert, Tarim basin area, and Gobi Desert, where the most severe dust storms have been reported. In the decades between 1954 and 2007, reports of annual dust storm occurrences at 753 Chinese meteorological sites and the corresponding amount of total precipitation show a reduction in the occurrence and intensity of dust storms and clearly demonstrate an inverse relationship between the two. The correlation between dust storm occurrence and temperature in northwestern China also displays a negative trend but is less significant. Using a global climate model, we demonstrate that increased loading of light-absorbing aerosols in China, such as black carbon (BC), is the primary reason for precipitation and temperature increases over northwestern China, and the consequence of reductions in dust storm frequency and intensity. The model-simulated precipitation and temperature changes over northwestern China compare reasonably well with observed trends when a certain portion of absorbing aerosols has been added to the model, which significantly affects regional climate patterns through the heating of the air column. Anomalies of the observed annual total dust storm cases during the period from 1954 to 2007 (solid) and the corresponding anomalies of the observed annual mean (a) total precipitation (mm) and (b) surface temperature (C°) (dashed), along

  5. Structural relationship of the Beartooth Mountains and Big Horn basin in south-central Montana and northwestern Wyoming

    SciTech Connect

    Clark, D.M. )

    1991-06-01

    Geologic structure along the Beartooth Mountain front and adjacent Big Horn basin in south-central Montana and northwestern Wyoming has been the subject of considerable debate for many years. Directional drilling by Amoco Production Company, located on the northeast corner of the Beartooth block, indicates three things. (1) Western Big Horn basin Paleozoic and Mesozoic sections recumbently folded 2 mi (3.2 km) under the northeast corner of the Beartooth block, measured horizontally from the surface exposure of the Beartooth fault. (2) The main Beartooth fault dips 19{degrees} northwest at a depth of 8,300 to 8,400 ft (2,530 to 2,560 km), 1 mi (1.6 km) from the surface exposure of the main Beartooth fault. (3) The main Beartooth fault appears to be a component of a complex fault system which horizontally displaces and faults-out formations in both the Paleozoic and Mesozoic section on the upper limb of the recumbent fold. In addition to the drilling data, interior Beartooth Mountain faults, with dominant northeast and east-west structural orientation, show reactivation of left-lateral movement, intersecting the Beartooth front and offsetting Paleozoic and Mesozoic sections 1-2 mi (1.6-3.2 km) horizontally. Reactivation of some of these faults seems to coincide with the intrusion of Tertiary (Eocene ) igneous bodies along some of the same structural trends. Beartooth front fold orientation and fault movement correlated with a reexamination of internal block fault systems lend additional weight to the argument of horizontal compression as a major factor in late Laramide formation of geologic structure along the northeast face of the Beartooth Mountains.

  6. Paleozoic-early Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China

    USGS Publications Warehouse

    Rui, Z.; Goldfarb, R.J.; Qiu, Y.; Zhou, T.; Chen, R.; Pirajno, F.; Yun, G.

    2002-01-01

    The late Paleozoic-early Mesozoic tectonic evolution of Xinjiang Autonomous Region, northwestern China provided a favorable geological setting for the formation of lode gold deposits along the sutures between a number of the major Eastern Asia cratonic blocks. These sutures are now represented by the Altay Shan, Tian Shan, and Kunlun Shan ranges, with the former two separated by the Junggar basin and the latter two by the immense Tarim basin. In northernmost Xinjiang, final growth of the Altaid orogen, southward from the Angara craton, is now recorded in the remote mid- to late Paleozoic Altay Shan. Accreted Early to Middle Devonian oceanic rock sequences contain typically small, precious-metal bearing Fe-Cu-Zn VMS deposits (e.g. Ashele). Orogenic gold deposits are widespread along the major Irtysh (e.g. Duyolanasayi, Saidi, Taerde, Kabenbulake, Akexike, Shaerbulake) and Tuergen-Hongshanzui (e.g. Hongshanzui) fault systems, as well as in structurally displaced terrane slivers of the western Junggar (e.g. Hatu) and eastern Junggar areas. Geological and geochronological constraints indicate a generally Late Carboniferous to Early Permian episode of gold deposition, which was coeval with the final stages of Altaid magmatism and large-scale, right-lateral translation along older terrane-bounding faults. The Tian Shan, an exceptionally gold-rich mountain range to the west in the Central Asian republics, is only beginning to be recognized for its gold potential in Xinjiang. In this easternmost part to the range, northerly- and southerly-directed subduction/accretion of early to mid-Paleozoic and mid- to late Paleozoic oceanic terranes, respectively, to the Precambrian Yili block (central Tian Shan) was associated with 400 to 250 Ma arc magmatism and Carboniferous through Early Permian gold-forming hydrothermal events. The more significant resulting deposits in the terranes of the southern Tian Shan include the Sawayaerdun orogenic deposit along the Kyrgyzstan border and

  7. Exhumation history of the West Kunlun Mountains, northwestern Tibet: Evidence for a long-lived, rejuvenated orogen

    NASA Astrophysics Data System (ADS)

    Cao, Kai; Wang, Guo-Can; Bernet, Matthias; van der Beek, Peter; Zhang, Ke-Xin

    2015-12-01

    related to initial thrusting of the Tiklik fault and reactivation of the Tam Karaul thrust. Thrusting together with upper crustal shortening in the mountain front indicates basinward expansion of the West Kunlun orogen at this time. This episode of exhumation and uplift, associated with magmatism across western Tibet, is compatible with a double-sided lithospheric wedge model, primarily driven by breakoff of the Indian crustal slab. Accelerated exhumation of the mountain front at a rate of ∼1.1 km/Myr since ∼15 Ma supports active compressional deformation at the margins of the northwestern Tibetan Plateau. We thus propose that the West Kunlun Mountains are a long-lived topographic unit, dating back to Triassic-Early Jurassic times, and have experienced Middle-Late Mesozoic to Early Cenozoic rejuvenation and Late Oligocene-Miocene expansion.

  8. On the Lathrobium fauna of the Luoxiao Mountains, Central China.

    PubMed

    Peng, Zhong; Li, Li-Zhen; Zhao, Mei-Jun

    2016-01-01

    Thirteen species of Lathrobium Gravenhorst, 1802 are recorded from the Luoxiao Mountains, Central China, all of them micropterous and locally endemic. Eight species are described and illustrated: L. bamianense Peng & Li sp. n., L. fumingi Peng & Li sp. n., L. jinyuae Peng & Li sp. n., L. jiulingense Peng & Li sp. n., L. shuguangi Peng & Li sp. n., L. taiye Peng & Li sp. n., L. yangshimuense Peng & Li sp. n., and L. yipingae Peng & Li sp. n. Five probably undescribed species remain unnamed. Including the new taxa, 219 Lathrobium species are currently known from mainland China. PMID:27615892

  9. Himalayan Mountain Range, Taklimakan Desert, China

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Looking north from Kashmir India (27.5N, 76.5E) into the Tibetan Plateau and beyond, the Taklimakan Desert of far western China appears to be covered with an extensive layer of haze that blankets the entire region. Reaching even into the western Siberian Plains of the CIS. This rugged land is one of the world's richest treasure troves of mineral wealth but the accessability into this remote area is so difficult that it is not yet economically feasible.

  10. Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

    NASA Astrophysics Data System (ADS)

    Xin, Jinyuan; Gong, Chongshui; Wang, Shigong; Wang, Yuesi

    2016-05-01

    The optical properties of dust aerosols were measured using narrow-band data from a portable sun photometer at four desert and semi-desert stations in northwestern China from 2004 to 2007. Ground-based and satellite observations indicated absorbing dust aerosol loading over the region surrounded by eight large-scale deserts. Radiation forcing was identified by using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The ranges of annual mean aerosol optical depth (AOD), Angström exponents, and single-scattering albedo (SSA) were from 0.25 to 0.35, from - 0.73 to 1.18, and from 0.77 to 0.86, respectively. The ranges of annual mean aerosol direct radiative forcing values at the top of the atmosphere (TOA), mid-atmosphere, and on the surface were from 3.9 to 12.0, from 50.0 to 53.1, and from - 39.1 to - 48.1 W/m2, respectively. The aerosols' optical properties and radiative characteristics showed strong seasonal variations in both the desert and semi-desert regions. Strong winds and relatively low humidity will lead dust aerosols in the atmosphere to an increase, which played greatly affected these optical properties during spring and winter in northwestern China. Based on long-term observations and retrieved data, aerosol direct radiative forcing was confirmed to heat the atmosphere (50-53 W/m2) and cool the surface (- 39 to - 48 W/m2) above the analyzed desert. Radiative forcing in the atmosphere in spring and winter was 18 to 21 W/m2 higher than other two seasons. Based on the dust sources around the sites, the greater the AOD, the more negative the forcing. The annual averaged heating rates for aerosols close to the ground (1 km) were approximately 0.80-0.85 K/day.

  11. Northwestern salamanders Ambystoma gracile in mountain lakes: record oviposition depths among salamanders

    USGS Publications Warehouse

    Hoffman, R.; Pearl, C.A.; Larson, G.L.; Samora, B.

    2012-01-01

    Oviposition timing, behaviors, and microhabitats of ambystomatid salamanders vary considerably (Egan and Paton 2004; Figiel and Semlitsch 1995; Howard and Wallace 1985; Mac-Cracken 2007). Regardless of species, however, females typically oviposit using sites conducive to embryo development and survival. For example, the results of an experiment by Figiel and Semlitsch (1995) on Ambystoma opacum (Marbled Salamander) oviposition indicated that females actively selected sites that were under grass clumps in wet versus dry treatments, and surmised that environmental conditions such as humidity, moisture, and temperature contributed to their results. Other factors associated with ambystomatid oviposition and embryo survival include water temperature (Anderson 1972; Brown 1976), dissolved oxygen concentration (Petranka et al. 1982; Sacerdote and King 2009), oviposition depth (Dougherty et al. 2005; Egan and Paton 2004), and oviposition attachment structures such as woody vegetation (McCracken 2007; Nussbaum et al. 1983). Resetarits (1996), in creating a model of oviposition site selection for anuran amphibians, hypothesized that oviparous organisms were also capable of modifying oviposition behavior and site selection to accommodate varying habitat conditions and to minimize potential negative effects of environmental stressors. Kats and Sih (1992), investigating the oviposition of Ambystoma barbouri (Streamside Salamander) in pools of a Kentucky stream, found that females preferred pools without predatory Lepomis cyanellus (Green Sunfish), and that the number of egg masses present in a pool historically containing fish increased significantly the year after fish had been extirpated from the pool. Palen et al. (2005) determined that Ambystoma gracile (Northwestern Salamander) and Ambystoma macrodactylum (Longtoed Salamander) eggs were deposited either at increased depth or in full shaded habitats, respectively, as water transperancy to UV-B radiation increased.

  12. High diversity of nitrogen-fixing bacteria in the upper reaches of the Heihe River, northwestern China

    NASA Astrophysics Data System (ADS)

    Tai, X. S.; Mao, W. L.; Liu, G. X.; Chen, T.; Zhang, W.; Wu, X. K.; Long, H. Z.; Zhang, B. G.; Zhang, Y.

    2013-08-01

    Vegetation plays a key role in water conservation in the southern Qilian Mountains (northwestern China), located in the upper reaches of the Heihe River. Nitrogen-fixing bacteria are crucial for the protection of the nitrogen supply for vegetation in the region. In the present study, nifH gene clone libraries were established to determine differences between the nitrogen-fixing bacterial communities of the Potentilla parvifolia shrubland and the Carex alrofusca meadow in the southern Qilian Mountains. All of the identified nitrogen-fixing bacterial clones belonged to the Proteobacteria. At the genus level, Azospirillum was only detected in the shrubland soil, while Thiocapsa, Derxia, Ectothiorhodospira, Mesorhizobium, Klebsiella, Ensifer, Methylocella and Pseudomonas were only detected in the meadow soil. The phylogenetic tree was divided into five lineages: lineages I, II and III mainly contained nifH sequences obtained from the meadow soils, while lineage IV was mainly composed of nifH sequences obtained from the shrubland soils. The Shannon-Wiener index of the nifH genes ranged from 1.5 to 2.8 and was higher in the meadow soils than in the shrubland soils. Based on these analyses of diversity and phylogeny, the plant species were hypothesised to influence N cycling by enhancing the fitness of certain nitrogen-fixing taxa. The number of nifH gene copies and colony-forming units (CFUs) of the cultured nitrogen-fixing bacteria were lower in the meadow soils than in the shrubland soils, ranging from 0.4 × 107 to 6.9 × 107 copies g-1 soil and 0.97 × 106 to 12.78 × 106 g-1 soil, respectively. Redundancy analysis (RDA) revealed that the diversity and number of the nifH gene copies were primarily correlated with aboveground biomass in the shrubland soil. In the meadow soil, nifH gene diversity was most affected by altitude, while copy number was most impacted by soil-available K. These results suggest that the nitrogen-fixing bacterial communities beneath Potentilla

  13. Numerical simulation of the impact of reforestation on winter meteorology and environment in a semi-arid urban valley, Northwestern China.

    PubMed

    Yu, Ye; He, Jianjun; Zhao, Suping; Liu, Na; Chen, Jinbei; Mao, Hongjun; Wu, Lin

    2016-11-01

    Since 1999 Chinese government has made great effort to reforest the south and north mountains surrounding urban Lanzhou - a city located in a river valley, Northwestern China. Until 2009 obvious land use change occurred, with 69.2% of the reforested area been changed from grasslands, croplands, barren or sparsely vegetated land to closed shrublands and 20.6% from closed shrublands, grasslands, and croplands to forests. Reforestation changes land-surface properties, with possible impact on the evolution of atmospheric variables. To understand to what extent the local meteorology and environment could be affected by reforestation in winter, and through what processes, two sets of simulations were conducted using the Weather Research and Forecasting model (WRF) and the FLEXible PARTicle (FLEXPART) dispersion model for a control case with high-resolution remotely sensed land cover data for 2009 and a scenario assuming no reforestation since 1999. Results suggested that the changes in albedo, surface exchange coefficient and surface soil heat conductivity related to reforestation led to the changes in surface net radiation and surface energy partitioning, which in turn affected the meteorological fields and enhanced the mountain-valley wind circulation. Replacement of shrublands and grassland with forest in the south mountain through reforestation play a dominant role in the enhancement of mountain-valley wind circulation. Reforestation increased the amount of air exchanged between the valley and the outside during the day, with the largest hourly increase of 10% on calm weather days and a monthly mean hourly increase of 2% for the study period (Dec. 2009). Reforestation affected the spatial distribution of pollutants and slightly improved the urban air quality, especially in the eastern valley. Results from this study provide useful information for future urban air quality management and reforestation plan, and some experience for cities with similar situations in the

  14. Numerical simulation of the impact of reforestation on winter meteorology and environment in a semi-arid urban valley, Northwestern China.

    PubMed

    Yu, Ye; He, Jianjun; Zhao, Suping; Liu, Na; Chen, Jinbei; Mao, Hongjun; Wu, Lin

    2016-11-01

    Since 1999 Chinese government has made great effort to reforest the south and north mountains surrounding urban Lanzhou - a city located in a river valley, Northwestern China. Until 2009 obvious land use change occurred, with 69.2% of the reforested area been changed from grasslands, croplands, barren or sparsely vegetated land to closed shrublands and 20.6% from closed shrublands, grasslands, and croplands to forests. Reforestation changes land-surface properties, with possible impact on the evolution of atmospheric variables. To understand to what extent the local meteorology and environment could be affected by reforestation in winter, and through what processes, two sets of simulations were conducted using the Weather Research and Forecasting model (WRF) and the FLEXible PARTicle (FLEXPART) dispersion model for a control case with high-resolution remotely sensed land cover data for 2009 and a scenario assuming no reforestation since 1999. Results suggested that the changes in albedo, surface exchange coefficient and surface soil heat conductivity related to reforestation led to the changes in surface net radiation and surface energy partitioning, which in turn affected the meteorological fields and enhanced the mountain-valley wind circulation. Replacement of shrublands and grassland with forest in the south mountain through reforestation play a dominant role in the enhancement of mountain-valley wind circulation. Reforestation increased the amount of air exchanged between the valley and the outside during the day, with the largest hourly increase of 10% on calm weather days and a monthly mean hourly increase of 2% for the study period (Dec. 2009). Reforestation affected the spatial distribution of pollutants and slightly improved the urban air quality, especially in the eastern valley. Results from this study provide useful information for future urban air quality management and reforestation plan, and some experience for cities with similar situations in the

  15. An evaluation of a bed instability index as an indicator of habitat quality in mountain streams of the northwestern United States

    USGS Publications Warehouse

    Kusnierz, Paul C.; Holbrook, Christopher; Feldman, David L.

    2015-01-01

    Managers of aquatic resources benefit from indices of habitat quality that are reproducible and easy to measure, demonstrate a link between habitat quality and biota health, and differ between human-impacted (i.e., managed) and reference (i.e., nonimpacted or minimally impacted) conditions. The instability index (ISI) is an easily measured index that describes the instability of a streambed by relating the tractive force of a stream at bankfull discharge to the median substrate size. Previous studies have linked ISI to biological condition but have been limited to comparisons of sites within a single stream or among a small number of streams. We tested ISI as an indicator of human impact to habitat and biota in mountain streams of the northwestern USA. Among 1428 sites in six northwestern states, ISI was correlated with other habitat measures (e.g., residual pool depth, percent fine sediment) and indices of biotic health (e.g., number of intolerant macroinvertebrate taxa, fine sediment biotic index) and differed between managed and reference sites across a range of stream types and ecoregions. While ISI could be useful in mountain streams throughout the world, this index may be of particular interest to aquatic resource managers in the northwestern USA where a large dataset, from which ISI can be calculated, exists.

  16. An evaluation of a bed instability index as an indicator of habitat quality in mountain streams of the northwestern United States.

    PubMed

    Kusnierz, Paul C; Holbrook, Christopher M; Feldman, David L

    2015-08-01

    Managers of aquatic resources benefit from indices of habitat quality that are reproducible and easy to measure, demonstrate a link between habitat quality and biota health, and differ between human-impacted (i.e., managed) and reference (i.e., nonimpacted or minimally impacted) conditions. The instability index (ISI) is an easily measured index that describes the instability of a streambed by relating the tractive force of a stream at bankfull discharge to the median substrate size. Previous studies have linked ISI to biological condition but have been limited to comparisons of sites within a single stream or among a small number of streams. We tested ISI as an indicator of human impact to habitat and biota in mountain streams of the northwestern USA. Among 1428 sites in six northwestern states, ISI was correlated with other habitat measures (e.g., residual pool depth, percent fine sediment) and indices of biotic health (e.g., number of intolerant macroinvertebrate taxa, fine sediment biotic index) and differed between managed and reference sites across a range of stream types and ecoregions. While ISI could be useful in mountain streams throughout the world, this index may be of particular interest to aquatic resource managers in the northwestern USA where a large dataset, from which ISI can be calculated, exists. PMID:26189618

  17. An evaluation of a bed instability index as an indicator of habitat quality in mountain streams of the northwestern United States.

    PubMed

    Kusnierz, Paul C; Holbrook, Christopher M; Feldman, David L

    2015-08-01

    Managers of aquatic resources benefit from indices of habitat quality that are reproducible and easy to measure, demonstrate a link between habitat quality and biota health, and differ between human-impacted (i.e., managed) and reference (i.e., nonimpacted or minimally impacted) conditions. The instability index (ISI) is an easily measured index that describes the instability of a streambed by relating the tractive force of a stream at bankfull discharge to the median substrate size. Previous studies have linked ISI to biological condition but have been limited to comparisons of sites within a single stream or among a small number of streams. We tested ISI as an indicator of human impact to habitat and biota in mountain streams of the northwestern USA. Among 1428 sites in six northwestern states, ISI was correlated with other habitat measures (e.g., residual pool depth, percent fine sediment) and indices of biotic health (e.g., number of intolerant macroinvertebrate taxa, fine sediment biotic index) and differed between managed and reference sites across a range of stream types and ecoregions. While ISI could be useful in mountain streams throughout the world, this index may be of particular interest to aquatic resource managers in the northwestern USA where a large dataset, from which ISI can be calculated, exists.

  18. Environmental impacts of large-scale CSP plants in northwestern China.

    PubMed

    Wu, Zhiyong; Hou, Anping; Chang, Chun; Huang, Xiang; Shi, Duoqi; Wang, Zhifeng

    2014-01-01

    Several concentrated solar power demonstration plants are being constructed, and a few commercial plants have been announced in northwestern China. However, the mutual impacts between the concentrated solar power plants and their surrounding environments have not yet been addressed comprehensively in literature by the parties involved in these projects. In China, these projects are especially important as an increasing amount of low carbon electricity needs to be generated in order to maintain the current economic growth while simultaneously lessening pollution. In this study, the authors assess the potential environmental impacts of large-scale concentrated solar power plants. Specifically, the water use intensity, soil erosion and soil temperature are quantitatively examined. It was found that some of the impacts are favorable, while some impacts are negative in relation to traditional power generation techniques and some need further research before they can be reasonably appraised. In quantitative terms, concentrated solar power plants consume about 4000 L MW(-1) h(-1) of water if wet cooling technology is used, and the collectors lead to the soil temperature changes of between 0.5 and 4 °C; however, it was found that the soil erosion is dramatically alleviated. The results of this study are helpful to decision-makers in concentrated solar power site selection and regional planning. Some conclusions of this study are also valid for large-scale photovoltaic plants.

  19. Environmental impacts of large-scale CSP plants in northwestern China.

    PubMed

    Wu, Zhiyong; Hou, Anping; Chang, Chun; Huang, Xiang; Shi, Duoqi; Wang, Zhifeng

    2014-01-01

    Several concentrated solar power demonstration plants are being constructed, and a few commercial plants have been announced in northwestern China. However, the mutual impacts between the concentrated solar power plants and their surrounding environments have not yet been addressed comprehensively in literature by the parties involved in these projects. In China, these projects are especially important as an increasing amount of low carbon electricity needs to be generated in order to maintain the current economic growth while simultaneously lessening pollution. In this study, the authors assess the potential environmental impacts of large-scale concentrated solar power plants. Specifically, the water use intensity, soil erosion and soil temperature are quantitatively examined. It was found that some of the impacts are favorable, while some impacts are negative in relation to traditional power generation techniques and some need further research before they can be reasonably appraised. In quantitative terms, concentrated solar power plants consume about 4000 L MW(-1) h(-1) of water if wet cooling technology is used, and the collectors lead to the soil temperature changes of between 0.5 and 4 °C; however, it was found that the soil erosion is dramatically alleviated. The results of this study are helpful to decision-makers in concentrated solar power site selection and regional planning. Some conclusions of this study are also valid for large-scale photovoltaic plants. PMID:25183246

  20. Earthquake Probabilities and Magnitude Distribution in 100a along the Haiyuan Fault, northwestern China

    NASA Astrophysics Data System (ADS)

    Ran, H.

    2004-12-01

    The Haiyuan fault is a major seismogenic fault in north-central China. One of the most devastating great earthquake in 20th century occurred near Haiyuan in northwestern China in December 16, 1920. More than 220000 people were killed and thousands of towns and villages were destroyed during this devastating earthquake. A 230 km long left-lateral surface rupture zone formed along the Haiyuan fault during the earthquake with maximum left lateral displacement of 10 m. In recent years, some researchers have studied the paleoseismology along the Haiyuan fault and revealed a lot of paleoearthquake events. All available information allows more reliable analysis of earthquake recurrence interval and earthquake rupture patterns along the Haiyuan fault. Based on fault geometry, segmentation pattern, and paleoearthquake events along the Haiyuan fault we can identify three scales of earthquake rupture: rupture of one segment, cascade rupture of two segments, and cascade rupture of entire fault (three segments), and obtain the earthquake recurrence intervals of these scales of earthquake rupture. The earthquake probability and magnitude distribution in 100-year along the Haiyuan fault can be obtained through weighted computation, by applying these paleoseismological information mentioned above, using Possion and Brownian passage time model and considering different rupture patterns. The result shows that the earthquakes probability of is about 0.035 in 100-year along the Haiyuan fault.

  1. Geology and timing of mineralization at the Cangshang gold deposit, north-western Jiaodong Peninsula, China

    USGS Publications Warehouse

    Zhang, X.; Cawood, Peter A.; Wilde, S.A.; Liu, R.; Song, H.; Li, W.; Snee, L.W.

    2003-01-01

    The Cangshang gold deposit of the northwestern Jiaodong Peninsula contains reserves of greater than 50 tonnes (t) and is developed by the largest open pit gold mine in China. This deposit is a Jiaojia-style (i.e. disseminated-and-veinlet) deposit. It is controlled by the San-Cang fault zone, which trends ???040?? and dips 40-75??SE at the mine site. The main (no. 1) orebody lies between a hanging wall of Precambrian metamorphic rocks (mainly amphibolite) of the Fenzishan Group and a footwall composed of the Mesozoic Linglong granitoid. The ore zone is mainly composed of pyritized, sericitized and silicified granitoid, which has undergone variable degrees of cataclasis. SHRIMP U-Pb dating of zircon indicates that the protolith of the hanging wall amphibolite was formed at 2530 ?? 17 Ma and underwent metamorphism at 1852 ?? 37 Ma. The footwall granodiorite has been dated at 166 ?? 4 Ma, whereas zircons from the ore zone yield a younger age of 154 ?? 5 Ma. Cathodoluminescence images of zircons from the granodiorite and ore zone show oscillatory zonation indicative of an igneous origin for both and the ages of these zircons, therefore, are all interpreted to be representative of magmatic crystallization. Dating of sericite by 40Ar-39Ar has been used to directly determine the timing of formation of the Cangshang deposit, providing the first time absolute age on formation of the Jiaojia-style gold deposits. The well-defined age of 121.3 ?? 0.2 Ma provides the precise timing of gold mineralization at the Cangshang deposit. This age is consistent with those of Linglong-style (vein type) gold mineralization, also from the north-western Jiaodong Peninsula, at between 126 and 120 Ma. Therefore, our work indicates that both styles of gold deposits in the Jiaodong Peninsula were formed during the same mineralization event.

  2. Atmospheric pollutants in fog and rain events at the northwestern mountains of the Iberian Peninsula.

    PubMed

    Fernández-González, Ricardo; Yebra-Pimentel, Iria; Martínez-Carballo, Elena; Simal-Gándara, Jesús; Pontevedra-Pombal, Xabier

    2014-11-01

    Atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) and exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). While the hydrosphere is the main reservoir for PAHs, the atmosphere serves as the primary route for global transport of PCBs. In this study, fog and rain samples were collected during fourteen events from September 2011 to April 2012 in the Xistral Mountains, a remote range in the NW Iberian Peninsula. PAH compounds [especially of low molecular weight (LMW)] were universally found, but mainly in the fog-water samples. The total PAH concentration in fog-water ranged from non-detected to 216 ng·L(-1) (mean of 45 ng·L(-1)), and was much higher in fall than in winter. Total PAH levels in the rain and fog events varied from non-detected to 1272 and 33 ng·L(-1) for, respectively, LMW and high molecular weight (HMW) PAHs. Diagnostic ratio analysis (LMW PAHs/HMW PAHs) suggested that petroleum combustion was the dominant contributor to PAHs in the area. Total PCB levels in the rain and fog events varied from non-detected to 305 and 91 ng·L(-1) for, respectively, PCBs with 2-3 Cl atoms and 5-10 Cl atoms. PCBs, especially those with 5-10 Cl atoms, were found linked to rain events. The occurrence of the most volatile PCBs, PCBs with 2-3 Cl atoms, is related to wind transport from far away sources, whereas the occurrence of PCBs with 5-10 Cl atoms seems to be related with the increase of its deposition during rainfall at the end of summer and fall. The movement of this fraction of PCBs is facilitated by its binding to air-suspended particles, whose concentrations usually show an increase as the result of a prolonged period of drought in summer.

  3. Atmospheric pollutants in fog and rain events at the northwestern mountains of the Iberian Peninsula.

    PubMed

    Fernández-González, Ricardo; Yebra-Pimentel, Iria; Martínez-Carballo, Elena; Simal-Gándara, Jesús; Pontevedra-Pombal, Xabier

    2014-11-01

    Atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) and exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). While the hydrosphere is the main reservoir for PAHs, the atmosphere serves as the primary route for global transport of PCBs. In this study, fog and rain samples were collected during fourteen events from September 2011 to April 2012 in the Xistral Mountains, a remote range in the NW Iberian Peninsula. PAH compounds [especially of low molecular weight (LMW)] were universally found, but mainly in the fog-water samples. The total PAH concentration in fog-water ranged from non-detected to 216 ng·L(-1) (mean of 45 ng·L(-1)), and was much higher in fall than in winter. Total PAH levels in the rain and fog events varied from non-detected to 1272 and 33 ng·L(-1) for, respectively, LMW and high molecular weight (HMW) PAHs. Diagnostic ratio analysis (LMW PAHs/HMW PAHs) suggested that petroleum combustion was the dominant contributor to PAHs in the area. Total PCB levels in the rain and fog events varied from non-detected to 305 and 91 ng·L(-1) for, respectively, PCBs with 2-3 Cl atoms and 5-10 Cl atoms. PCBs, especially those with 5-10 Cl atoms, were found linked to rain events. The occurrence of the most volatile PCBs, PCBs with 2-3 Cl atoms, is related to wind transport from far away sources, whereas the occurrence of PCBs with 5-10 Cl atoms seems to be related with the increase of its deposition during rainfall at the end of summer and fall. The movement of this fraction of PCBs is facilitated by its binding to air-suspended particles, whose concentrations usually show an increase as the result of a prolonged period of drought in summer. PMID:25129155

  4. Sequence stratigraphy and continental margin development of the northwestern shelf of the South China Sea

    SciTech Connect

    Chen, P.P.H. ); Zhi Yuong Chen; Qi Min Zhang )

    1993-05-01

    Based on the sequence stratigraphic analyses of the Tertiary in the northwestern continental margin of the South China Sea, this paper summarizes the regional tectonics and their influences on the basin developments and discusses the systems tract distributions through the continental margin growth. The study area is underlain by two Tertiary basins separated by a major basin boundary fault across which two distinctly different basin structural styles developed. The Qiongdongnan basin shows characteristic rift structures and is closely related to the opening of the South China Sea. The Yinggehai basin is filled with thick Neogene monoclines overlying basement without apparent rift structures. The Yinggehai's genesis has been linked to the tectonism along the Red River suture zone. The margin development is characterized by depositional environments of sediment influx constantly exceeding accommodation space. Under these environments, the highstand deltas frequently developed near shelf edges, where vertically stacked shallow water sands of both highstand deltas and lowstand wedges/deltas could produce favorable exploration targets. High rates of sedimentation in the study area allow the identification of fourth-order cyclicity in the Quaternary. Regional sequence stratigraphic correlations suggest that many sequence boundaries appear to be synchronous, but not all boundaries exist in all basins along the eastern and southern continental margins of mainland China. The margin evolved through the repeated development of lowstand fans, lowstand wedges, transgressive systems tracts, and highstand deltas. Prior to the Pliocene, the shelf was sourced both from Vietnam and Hainan Island and, as a result, two shelf margins developed. The southwestern margin stopped growing in the late Miocene, and the northern margin continued to prograde with possible additional sediment inputs through the Red River system in the Quaternary. 29 refs., 22 figs.

  5. Secondary salinization and evapotranspiration under mulched drip irrigation condition in Tarim River basin of northwestern China

    NASA Astrophysics Data System (ADS)

    Tian, Fuqiang; Hu, Hongchang; Zhang, Zhi; Hu, Heping

    2013-04-01

    The secondary salinization induced by irrigation has been presented as a crucial threat to agriculture all over the world, especially in semi-arid and arid regions. Mulched drip irrigation (MDI), as a new micro-irrigation approach incorporating surface drip irrigation method and film mulching technique, has been widely applied in water scarce regions including Tarim River basin of northwestern China. However, salts are likely to build up in the surface soil due to the deficient leaching water in such an irrigation condition. To explore this new kind of secondary salinization issue, the oasis eco-hydrology experimental research station were established in 2008 in a cotton field of Xinjiang, northwestern China. More than 40,000 soil samples were collected to monitor soil moisture and salinity condition within the 1.5 meter depth. The patterns of soil salinity distribution under MDI along the horizontal direction as well as vertical direction have been explored. The results did show that secondary salinization tends to occur in the experimental field under mulched drip irrigation, and winter flush could leach most soil salt in the root zone into groundwater and keep salt balance to mitigate the soil salinization. Meanwhile, soil salt always migrates with the soil water flux such as irrigation and groundwater recharge. Therefore the understanding of water balance is of great importance for estimating soil salinity accumulation, of which evapotranspiration (ET) is the key process, especially in the semi-arid and arid area. In our study, in order to quantify the relation between salinity balance and water balance, ET were derived from a range of measurement systems including eddy covariance, soil water budget (gravimetric methods, Hydra probe, TDT probe and groundwater table sensor, et al.), sap flow and portable photosynthetic system during cotton growing period. Our study is unique in its focus on ET scale issue ranging from leaf and plant scale to field. The up

  6. Radiocarbon-dated archaeological record of early first millennium B.C. mounted pastoralists in the Kunlun Mountains, China.

    PubMed

    Wagner, Mayke; Wu, Xinhua; Tarasov, Pavel; Aisha, Ailijiang; Ramsey, Christopher Bronk; Schultz, Michael; Schmidt-Schultz, Tyede; Gresky, Julia

    2011-09-20

    Pastoral nomadism, as a successful economic and social system drawing on mobile herding, long-distance trade, and cavalry warfare, affected all polities of the Eurasian continent. The role that arid Inner Asia, particularly the areas of northwestern China, Kazakhstan, and Mongolia, played in the emergence of this phenomenon remains a fundamental and still challenging question in prehistoric archaeology of the Eurasian steppes. The cemetery of Liushiu (Xinjiang, China) reveals burial features, bronze bridle bits, weaponry, adornment, horse skulls, and sheep/goat bones, which, together with paleopathological changes in human skeletons, indicate the presence of mobile pastoralists and their flocks at summer pastures in the Kunlun Mountains, ∼2,850 m above sea level. Radiocarbon dates place the onset of the burial activity between 1108 and 893 B.C. (95% probability range) or most likely between 1017 and 926 B.C. (68%). These data from the Kunlun Mountains show a wider frontier within the diversity of mobile pastoral economies of Inner Asia and support the concept of multiregional transitions toward Iron Age complex pastoralism and mounted warfare.

  7. Radiocarbon-dated archaeological record of early first millennium B.C. mounted pastoralists in the Kunlun Mountains, China

    PubMed Central

    Wagner, Mayke; Wu, Xinhua; Tarasov, Pavel; Aisha, Ailijiang; Ramsey, Christopher Bronk; Schultz, Michael; Schmidt-Schultz, Tyede; Gresky, Julia

    2011-01-01

    Pastoral nomadism, as a successful economic and social system drawing on mobile herding, long-distance trade, and cavalry warfare, affected all polities of the Eurasian continent. The role that arid Inner Asia, particularly the areas of northwestern China, Kazakhstan, and Mongolia, played in the emergence of this phenomenon remains a fundamental and still challenging question in prehistoric archaeology of the Eurasian steppes. The cemetery of Liushiu (Xinjiang, China) reveals burial features, bronze bridle bits, weaponry, adornment, horse skulls, and sheep/goat bones, which, together with paleopathological changes in human skeletons, indicate the presence of mobile pastoralists and their flocks at summer pastures in the Kunlun Mountains, ∼2,850 m above sea level. Radiocarbon dates place the onset of the burial activity between 1108 and 893 B.C. (95% probability range) or most likely between 1017 and 926 B.C. (68%). These data from the Kunlun Mountains show a wider frontier within the diversity of mobile pastoral economies of Inner Asia and support the concept of multiregional transitions toward Iron Age complex pastoralism and mounted warfare. PMID:21911387

  8. An assessment of restoration success to forests planted for ecosystem restoration in loess plateau, Northwestern China.

    PubMed

    Yang, Zhanbiao; Jin, Hongxi; Wang, Gang

    2010-05-01

    Using ecosystem attributes identified by the Society of Ecological Restoration International, we assessed three restoration projects in the loess plateau, northwestern China, including planting Larix principis-rupprechtii (LS) and Pinus tabulaeformis (PS) on shrubland, and planting L. principis-rupprechtii on open forest land (LO). The reestablishment of native species in LS and PS was poorer than LO because of the excessive stand density. Species diversity, seedling number, and seedling diversity were significantly higher in LO than in LS and PS. Soil nutrient was also significantly higher in the LO treatment. The vegetation composition, species diversity, and soil nutrient in LO, however, were more similar to these in the reference. Our results indicate that planting L. principis-rupprechtii on open forest land had accelerated the succession of the ecosystem for approximately 30 years. But the poor natural regeneration of L. principis-rupprechtii suggests that post-planting activities in LO are required after timber harvesting or the natural mortality of the L. principis-rupprechtii. Management operation such as selective thinning will be required in LS and PS to promote the true restoration of native species diversity in the future.

  9. Atmospheric significance of aeolian salts in the sandy deserts of northwestern China

    NASA Astrophysics Data System (ADS)

    Zhu, B.-Q.

    2016-02-01

    Large sandy deserts in the middle latitudes of northwestern China were investigated for soluble salt variations in modern and ancient aeolian sediments, aiming to explore the environmental significance of "aeolian salts". Results revealed that aeolian salt variations have a clear relationship with the changing meridional and zonal gradients of the desert locations and the aeolian differentiation effect, but are weakly linked to local geological conditions. Atmospheric depositions of water-soluble chemical species are an important process/source contributing to aeolian salt. Sequential variations of soluble salts in sedimentary profiles interbedded with aeolian and non-aeolian deposits and their palaeoenvironmental implications in the hinterland areas of these deserts were further evaluated, based on the constraints of OSL dating and radiocarbon dating data. The results indicate that inorganic salts may be a latent geoproxy in revealing regional palaeoclimatic changes in desert areas for sediments deposited under a single depositional environment, but the interpretation should be more cautious for sediments deposited under diverse depositional conditions. This study presents evidence of the atmospheric origin of aeolian salt in sandy deserts, with limited climatic significance in palaeoenvironmental reconstruction.

  10. Ecohydrological factors affecting nitrate concentrations in a phreatic desert aquifer in northwestern China

    USGS Publications Warehouse

    Gates, J.B.; Böhlke, J.K.; Edmunds, W.M.

    2008-01-01

    Aerobic conditions in desert aquifers commonly allow high nitrate (NO 3-) concentrations in recharge to persist for long periods of time, an important consideration for N-cycling and water quality. In this study, stable isotopes of NO3- (??15N NO3 and ??18ONO3) were used to trace NO3- cycling processes which affect concentrations in groundwater and unsaturated zone moisture in the arid Badain Jaran Oesert in northwestern China. Most groundwater NO3- appears to be depleted relative to Cl- in rainfall concentrated by evapotranspiration, indicating net N losses. Unsaturated zone NO 3- is generally higher than groundwater NO 3- in terms of both concentration (up to 15 476 ??M, corresponding to 3.6 mg NO3--N per kg sediment) and ratios with Cl-. Isotopic data indicate that the NO3- derives primarily from nitrification, with a minor direct contribution of atmospheric NO3- inferred for some samples, particularly in the unsaturated zone. Localized denitrification in the saturated zone is suggested by isotopic and geochemical indicators in some areas. Anthropogenic inputs appear to be minimal, and variability is attributed to environmental factors. In comparison to other arid regions, the sparseness of vegetation in the study area appears to play an important role in moderating unsaturated zone NO3- accumulation by allowing solute flushing and deterring extensive N2 fixation. ?? 2008 American Chemical Society.

  11. An assessment of restoration success to forests planted for ecosystem restoration in loess plateau, Northwestern China.

    PubMed

    Yang, Zhanbiao; Jin, Hongxi; Wang, Gang

    2010-05-01

    Using ecosystem attributes identified by the Society of Ecological Restoration International, we assessed three restoration projects in the loess plateau, northwestern China, including planting Larix principis-rupprechtii (LS) and Pinus tabulaeformis (PS) on shrubland, and planting L. principis-rupprechtii on open forest land (LO). The reestablishment of native species in LS and PS was poorer than LO because of the excessive stand density. Species diversity, seedling number, and seedling diversity were significantly higher in LO than in LS and PS. Soil nutrient was also significantly higher in the LO treatment. The vegetation composition, species diversity, and soil nutrient in LO, however, were more similar to these in the reference. Our results indicate that planting L. principis-rupprechtii on open forest land had accelerated the succession of the ecosystem for approximately 30 years. But the poor natural regeneration of L. principis-rupprechtii suggests that post-planting activities in LO are required after timber harvesting or the natural mortality of the L. principis-rupprechtii. Management operation such as selective thinning will be required in LS and PS to promote the true restoration of native species diversity in the future. PMID:19373438

  12. Correlations between environmental factors and wild bee behavior on alfalfa (Medicago sativa) in northwestern China.

    PubMed

    Wang, Xiaojuan; Liu, Hongping; Li, Xiaoxia; Song, Yu; Chen, Li; Jin, Liang

    2009-10-01

    To discover the effect of environmental factors on pollinator visitation to flowering Medicago sativa, several field experiments were designed to examine the diurnal movement patterns of wild bee species in the Hexi Corridor of northwestern China. Our study results showed that Megachile abluta, M. spissula, and Xylocopa valga showed unimodal diurnal foraging behavior, whereas Andrena parvula and Anthophora melanognatha showed bimodal diurnal foraging behavior. Correlation analysis indicated that diurnal foraging activities of pollinators were significantly correlated with environmental factors. Correlations of foraging activities versus environmental factors for M. abluta, M. spissula, and X. valga best fit a linear model, whereas those of A. parvula and A. melanognatha best fit a parallel quadratic model. Results of this study indicated that solitary wild bees such as M. abluta, M. spissula, X. valga, A. parvula, and A. melanognatha are potential alfalfa pollinators in the Hexi Corridor. An understanding of the environmental factors that affect the behaviors of different wild bees foraging in alfalfa are basic to the utilization of solitary wild bees in a practical way for increased, or more consistent, pollination of alfalfa for seed production. PMID:19825303

  13. Diverse nodule bacteria were associated with Astragalus species in arid region of northwestern China.

    PubMed

    Chen, Weimin; Sun, Liangliang; Lu, Jianjun; Bi, Liangliang; Wang, Entao; Wei, Gehong

    2015-01-01

    The legume species of Astragalus as traditional Chinese medicine source and environmental protection plants showed an extensive distribution in the arid region of northwestern China. However, few rhizobia associating with Astragalus have been investigated in this region so far. In this study, 78 endophytic bacteria were isolated from root nodules of 12 Astragalus species and characterized by the PCR-RFLP of 16S rRNA gene and symbiotic genes together with the phylogenetic analysis. Results showed that the majority (53%) of isolates are non-nodulating Agrobacterium sp. and the rest are Mesorhizobium genomic species (41%), Ensifer spp. and Rhizobium gallicum (6%), respectively. Mesorhizobium genomic species are broadly distributed in the Astragalus symbioses and most of them share similar symbiotic genes. It seems that horizontal gene transfer occurred frequently among different genomic species independent of their original hosts and sites. Astragalus adsurgens is nodulated by a widely range of rhizobial species in the nodulation test, revealing that it could play an important role in diversification of Astragalus symbionts and that might be a reason for its wide adaptation to diverse environments.

  14. Hydrological indications of aeolian salts in mid-latitude deserts of northwestern China

    NASA Astrophysics Data System (ADS)

    Zhu, Bing-Qi

    2016-06-01

    Large sandy deserts in middle latitude of northwestern China were studied on salt variations in modern and ancient aeolian sediments, aiming to explore their hydrological indications at the present and past. Globally, sulphate is rich in arid to semi-arid deserts, including the aeolian loess sediments in China and soils in low-latitude deserts, but is less common in the aeolian sediments from the mid-latitude deserts in this study. The compositional differences between aeolian salts and local natural waters is evident, indicating the chemistry of aeolian salts and the associated parent brines may be significantly different than that predicted for hydrologically closed systems. The formation of aeolian salts in the studied deserts is strongly controlled by earth surface processes in a large scale but not in a local scale. Vertical changes in facies and salinities are abrupt in the studied palaeo-aeolian sediment samples, which were interbedded by lacustrine/fluvial sediments with OSL and 14C ages ranging between 40 and 2 ka BP, reflecting rapid high-amplitude changes in hydrological settings during late Pleistocene to later Holocene in these ancient playa systems. A great difference in salt composition between aeolian and lacustrine sediments suggests that the inorganic salt is a latent geoproxy in revealing local hydrological variations and climate change in the desert areas. But the environmental indications could be amphibolous for the sedimentary sequences with dual/multiple depositional end-members; under this situation an increase in sequence salinity does not always represent an enhanced environmental aridity. Ancient playas are arid or humid at the same time based on several sporadic records is not a valid approach to correlation of salt deposits in adjacent saline playa basin in the studied areas. Effects of earth surface processes including erosion, deposition and other processes on sediment properties will bias the hydrological implications of sediment

  15. Perceived resource support for chronic illnesses among diabetics in north-western China.

    PubMed

    Zhong, Huiqin; Shao, Ya; Fan, Ling; Zhong, Tangshen; Ren, Lu; Wang, Yan

    2016-06-01

    A high level of social support can improve long-term diabetes self-management. Support from a single source has been evaluated. This study aims to analyze support from multiple and multilevel sources for diabetic patients by using the Chronic Illness Resources Survey (CIRS). Factors influencing the utilization of the CIRS were also evaluated. A total of 297 patients with diabetes were investigated using the CIRS and Perceived Diabetes Self-management Scale in Shihezi City, China. Descriptive statistics were used to explain demographic variables and scores of the scales. Factors affecting the utilization of chronic illness resources were determined through univariate analysis and then examined by multivariate logistic regression analysis. Of the 297 diabetic patients surveyed, 67% failed to reach the standard (more than 3 points) of utilizing chronic illness resources. Moreover, utilization of chronic illness resources was positively moderately correlated with self-management of diabetes (r = 0.75, P < 0.05). According to the multivariate logistic regression analysis, age (OR, 3.42; 95%CI, 1.19-9.84) and monthly income (OR, 5.27; 95%CI, 1.86-14.90) were significantly positively associated with the CIRS score. Individuals with high school (OR, 2.61; 95%CI, 1.13-6.05) and college (OR, 3.02; 95%CI, 1.13-8.04) degrees obtained higher scores in the survey than those with elementary school education. Results indicated that utilization of resources and support for chronic illness self-management, particularly personal adjustment and organization, were not ideal among diabetics in the communities of north-western China. Improved utilization of chronic illness resources was conducive for proper diabetes self-management. Furthermore, the level of utilization of chronic illness resources increased with age, literacy level, and monthly income. PMID:27075460

  16. Lake-level Fluctuation and Climate Cyclicity Observed in Lake Strata in the Northwestern Qaidam Basin, China

    NASA Astrophysics Data System (ADS)

    Riegel, H. B.; Heermance, R. V., III; Nie, J.; Su, Q.; Garzione, C. N.

    2015-12-01

    The Pliocene and Quaternary are times of rapid, extreme climate variability, but 3-D geologic exposures of lacustrine strata from this time are rare, impeding observations of the impact of climate-change on lake sedimentation. The Qaidam Basin (QB) in western China provides a unique geologic setting, where internally drained lakes have existed for the past few million years, and recent deformation of the basin floor has uplifted and exposed lacustrine strata. This stratigraphy records a detailed history of lake level fluctuation, evaporite deposition, and climate change. We provide new paleomagnetic, δ18O and δ13C data combined with detailed sedimentology from the lower 475 m of a 900 m thick stratigraphic section (38.28N, 91.54E) in the northwestern QB to reveal a high-resolution record of sedimentation and climate change during the Plio-Quaternary. 12 magnetozones indicate an age for the lower half of the section between 6.0-3.0 Ma. The section consists of 9 lithofacies (1 mudstone, 4 sandstone, 1 conglomerate, 2 gypsum, 1 halite) that can be divided into 3 stratigraphic units based on evaporite concentration. Alternating mud, gypsum, and halite beds imply multiple lake-level fluctuations and occasional complete drying of the lake. This is consistent with >12.5‰ variation in the δ18O values of lacustrine carbonates (δ18Oc), indicating large-scale lake level fluctuation below 410 m, consistent with the boundary of Unit 1 and 2. Between 410 and 475 m, the δ18Oc values are ~-5 ‰. Above 475 m, an increase in gypsum concentration causes a thick salt-crust to develop on the outcrop, making sampling impossible. This stratigraphic level corresponds to an age of ~3.0 Ma, when the QB became hyper-arid. The presence of gypsum and halite throughout the section implies that the QB was arid and internally drained by at least 6 Ma, although the basin may have been divided into multiple lakes based on the bimodal δ18O values from different parts of the QB during that

  17. Mapping Water Use Efficiency for the Xinjiang Province in Northwestern China

    NASA Astrophysics Data System (ADS)

    Veroustraete, F.; Verstraeten, W.; Li, Q.; Dong, Q.; van Roey, T.

    2007-12-01

    The Tarim river basin, one of the basins integrated in the UNESCO - HELP Programme, is located in the Xinjiang Autonomous Region in Northwestern China. It is one of the world's largest closed hydrological drainage systems, and has ideal soils for agriculture, if enough water is available. Farmers in the province produce one- sixth of China's total cotton production. Since the 1950's however, excessive land reclamation, over-grazing and increased utilization of water resources in the upper reaches of the basin intensified environmental degradation. This impacted on cattle stock reduction (by water shortage), withered poplars and vegetation, along the lower reaches of the basin. Riparian forest degraded with a reduction in its area of 200 000 ha in total. Higher water use combined with a gradual mean yearly temperature increase due to climate change caused serious hydrological problems in the basin. Since the 1970's a strong drying out of the lower region is elicited. This phenomenon degraded the basin's downstream ecosystems, with an expansion of desertification as a consequence. Quite conspicuously, the Tarim river has shortened by 320 km, onward the period mentioned above. In the lower region of the basin, the situation is very serious. It can in fact be described as an ecological disaster, with dying trees and vegetation, the drying out of rivers and as consequence a regression of the river fish population as well as increased salt deposits. In the ARCHIMOD bilateral project between Belgium and China, important objectives are the description of the phenomena cited above using hydraulic modelling for some sub-basins of the Tarim as well as the application of remote sensing to estimate evapotranspiration (ETR), soil moisture content (SMC) and water use efficiency (WUE) at the scale of the Xinjiang province. Te estimate WUE at this scale the carbon exchange model C-Fix was applied. Our paper focusses on the application of remote sensing to map WUE for the Xinjiang

  18. Analyzing the Effects of Dust on Atmospheric Composition over Northwestern China in Spring 2008 Using WRF-Chem

    NASA Astrophysics Data System (ADS)

    Wang, J.; Allen, D. J.; Pickering, K. E.; Li, Z.

    2014-12-01

    Adjacent to the Taklimakan and Gobi deserts, northwestern China experiences dust storms frequently during the spring season. With the population and industry in northwestern China growing rapidly, anthropogenic pollution also impacts the aerosol composition and therefore optical properties and radiative effects. For instance, NOx emissions from Gansu province increased from ~195 Gg/yr in 2000 to ~323 Gg/yr in 2006 due to the fast growth of transportation vehicles, while SO2 emissions dropped from ~439 Gg/yr to ~338 Gg/yr because flue-gas desulfurization (FGD) devices are widely used in coal-fired powerplants. The WRF-Chem model with CBMZ chemistry mechanism, MOSAIC 8-bins aerosol module and GOCART dust emission algorithm, is applied to simulate the processes responsible for temporal changes in the aerosol distribution, aerosol optical properties and size distribution in Northwestern China due to the impact of dust and anthropogenic emissions during spring 2008, a time period during which an intensive field campaign was conducted at the Zhangye National Climate Observatory (39.082°N, 100.276°E, 1460 m above sea level) of the China Meteorological Administration. This field campaign provided observations of meteorological fields, radiative fluxes, trace gases concentrations, aerosol optical properties, and aerosol size distributions to evaluate the model simulation. The observational data showed a pronounced diurnal variation of trace gases and aerosols: low in the afternoon and high in the morning. Elevated pollutant levels were observed in several dust storms during this campaign. We will investigate the atmospheric processes that are responsible for the atmospheric composition, and assess the relative impact of dust and anthropogenic emissions on local air quality.

  19. Quantifying the Intra-Regional Precipitation Variability in Northwestern China over the Past 1,400 Years

    PubMed Central

    Lee, Harry F.; Pei, Qing; Zhang, David D.; Choi, Kan P. K.

    2015-01-01

    There has been a surge of paleo-climatic/environmental studies of Northwestern China (NW China), a region characterized by a diverse assortment of hydro-climatic systems. Their common approach, however, focuses on “deducing regional resemblance” rather than “exploring regional variance.” To date, efforts to produce a quantitative assessment of long-term intra-regional precipitation variability (IRPV) in NW China has been inadequate. In the present study, we base on historical flood/drought records to compile a decadal IRPV index for NW China spanned AD580–1979 and to find its major determinants via wavelet analysis. Results show that our IRPV index captures the footprints of internal hydro-climatic disparity in NW China. In addition, we find distinct ~120–200 year periodicities in the IRPV index over the Little Ice Age, which are attributable to the change of hydro-climatic influence of ocean-atmospheric modes during the period. Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China. The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records. It may help to comprehend the complex hydro-climatic regimes in the region. PMID:26154711

  20. Quantifying the Intra-Regional Precipitation Variability in Northwestern China over the Past 1,400 Years.

    PubMed

    Lee, Harry F; Pei, Qing; Zhang, David D; Choi, Kan P K

    2015-01-01

    There has been a surge of paleo-climatic/environmental studies of Northwestern China (NW China), a region characterized by a diverse assortment of hydro-climatic systems. Their common approach, however, focuses on "deducing regional resemblance" rather than "exploring regional variance." To date, efforts to produce a quantitative assessment of long-term intra-regional precipitation variability (IRPV) in NW China has been inadequate. In the present study, we base on historical flood/drought records to compile a decadal IRPV index for NW China spanned AD580-1979 and to find its major determinants via wavelet analysis. Results show that our IRPV index captures the footprints of internal hydro-climatic disparity in NW China. In addition, we find distinct ~120-200 year periodicities in the IRPV index over the Little Ice Age, which are attributable to the change of hydro-climatic influence of ocean-atmospheric modes during the period. Also, we offer statistical evidence of El Niño Southern Oscillation (Indo-Pacific warm pool sea surface temperature and China-wide land surface temperature) as the prominent multi-decadal to centennial (centennial to multi-centennial) determinant of the IRPV in NW China. The present study contributes to the quantitative validation of the long-term IRPV in NW China and its driving forces, covering the periods with and without instrumental records. It may help to comprehend the complex hydro-climatic regimes in the region.

  1. The Hei River Basin in northwestern China - tectonics, sedimentary processes and pathways

    NASA Astrophysics Data System (ADS)

    Rudersdorf, Andreas; Nottebaum, Veit; Schimpf, Stefan; Yu, Kaifeng; Hartmann, Kai; Stauch, Georg; Wünnemann, Bernd; Reicherter, Klaus; Diekmann, Bernhard; Lehmkuhl, Frank

    2014-05-01

    The Hei River Basin (catchment area of c. 130,000 km²) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper

  2. The Sap Flow Dynamics and Response of Hedysarum scoparium to Environmental Factors in Semiarid Northwestern China

    PubMed Central

    Deng, Jifeng; Ding, Guodong; Gao, Guanglei; Wu, Bin; Zhang, Yuqing; Qin, Shugao; Fan, Wenhui

    2015-01-01

    Hedysarum scoparium is an important, fast-growing and drought-resistant shrub that has been extensively used for grassland restoration and preventing desertification in semiarid regions of northwestern China. The primary objective of this study was to investigate the diurnal and seasonal variations in stem sap flow (Js) and its relation to environmental factors. The stem heat balance method was applied to plants that were approximately 17 years old (with diameters of 25, 16, 13, and 9 mm at ground level and heights of 3.1, 1.8, 1.7 and 1.4 m) and growing under natural conditions. The vertical soil temperature profile (ST), soil surface heat flux (SoilG), volumetric soil moisture content (SWC) and meteorological variables such as solar radiation (Rn), air temperature (Ta), vapour pressure deficit (VPD), wind speed (Ws) relative humidity (RH) and precipitation (P) were simultaneously measured at a meteorological station on site. Results indicated that Js varied regularly during the diurnal and seasonal term. The nocturnal Js was substantial, with a seasonal variation similar to the patterns of daytime Js. The magnitude of Js changed considerably between sunny and rainy days. Redundancy (RDA) and Kendall’s tau analysis suggested that daily Js in large plants was more sensitive to environmental factors, and the variation in daily Js during the growing season could be described by a multiple linear regression against environmental variables including Ta, VPD, Ws, RH, ST, and SoilG. While the nocturnal Js in smaller plants was more sensitive to meteorological factors. Ta, VPD, and Ws were significantly correlated with nighttime Js. The hourly nighttime sap flow rate of H. scoparium corresponded closely to Ta and VPD following a non-linear pattern. The results of this study can be used to estimate the transpiration of H. scoparium. PMID:26136229

  3. No Red River capture since the late Oligocene: Geochemical evidence from the Northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhao, Meng; Shao, Lei; Liang, Jianshe; Li, Qianyu

    2015-12-01

    Rare earth elements (REE) in the sediment samples of six industrial wells from the Yinggehai-Song Hong Basin in the Northwestern South China Sea were analyzed and compared with the detrital zircon U-Pb data from earlier studies to extrapolate sediment provenance. The results reveal that the Red River (Song Hong River), Hainan Island and Central Vietnam have been the main provenances of the Yinggehai-Song Hong Basin since the late Oligocene. The Red River has been supplying sediments with positive Eu anomalies from basic-ultrabasic metamorphic and volcanic parent rocks to most parts of the basin, while Hainan Island has delivered sediments with negative Eu anomalies from granitic and sedimentary parent rocks to the eastern slope area of the basin. The progradational downlap structures in the seismic profiles also support the finding that the sediment supply is mainly from the Red River and from Hainan Island. The metamorphic rocks, which are widespread within the Red River drainage, not only provided high volumes of sediments to the basin but also contributed to the positive Eu anomalies observed. Because their REE and U-Pb signatures are similar to those of the Red River source, the metamorphic and igneous rocks of the Song Ma Suture Zone, Kontum Massif, and Jinghong area were probably parts of a large basic provenance region before being separated by strike-slip movements along the Ailao Shan-Red River shear zone. Furthermore, our results indicate that the Red River drainage area has been relatively stable since the late Oligocene. Therefore, if a drainage capture from the Red River occurred, it is likely to have taken place before the late Oligocene.

  4. Magnetostratigraphy of the Kelasu section in the Baicheng depression, Southern Tian Shan, northwestern China

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiliang; Shen, Zhongyue; Sun, Jimin; Wang, Xin; Tian, Zhonghua; Pan, Xiaoqing; Shi, Linquan

    2015-11-01

    In order to better constrain chronology of the Cenozoic sediments in the foreland basin of the Southern Tian Shan, we carried out a magnetostratigraphic study along the Kelasu River, in the Baicheng depression, northwestern China. This is the basis for future studies of the tectonic shortening history and paleoclimatic changes. Stepwise thermal demagnetization was used to isolate the high-temperature characteristic component (ChRM) from 1521 oriented samples collected along two overlapped sections. The ChRM directions are interpreted to be acquired at or close to the time of rock formation. A composite magnetostratigraphic column composed of 86 (45 normal and 41 reversed) polarity chrons can correlate with GPTS (CK95) from ∼54 Ma to ∼7.6 Ma. The basal ages of the Kumugeliemu, Suweiyi, Jidike and the Kangcun formations are ∼54 Ma, ∼46 Ma, ∼34 Ma and ∼9.7 Ma, respectively. The changes of anisotropy of magnetic susceptibility (AMS) parameters (Pj and T) cannot be used to reflect the Cenozoic uplift of the southern Chinese Tian Shan due to the parameters have a significant linear positive correlation with the bulk magnetic susceptibility (Km), suggesting a sedimentary provenance control. Based on the alignments of the AMS, we concluded that the paleo-river channel flowed from north to south, being similar to the present river flowing direction, suggesting that there was still a residue relief of the Tian Shan orogen after the long-term Mesozoic denudation or the reactivation of the Tian Shan may have been initiated as early as ∼54 Ma.

  5. The Sap Flow Dynamics and Response of Hedysarum scoparium to Environmental Factors in Semiarid Northwestern China.

    PubMed

    Deng, Jifeng; Ding, Guodong; Gao, Guanglei; Wu, Bin; Zhang, Yuqing; Qin, Shugao; Fan, Wenhui

    2015-01-01

    Hedysarum scoparium is an important, fast-growing and drought-resistant shrub that has been extensively used for grassland restoration and preventing desertification in semiarid regions of northwestern China. The primary objective of this study was to investigate the diurnal and seasonal variations in stem sap flow (Js) and its relation to environmental factors. The stem heat balance method was applied to plants that were approximately 17 years old (with diameters of 25, 16, 13, and 9 mm at ground level and heights of 3.1, 1.8, 1.7 and 1.4 m) and growing under natural conditions. The vertical soil temperature profile (ST), soil surface heat flux (SoilG), volumetric soil moisture content (SWC) and meteorological variables such as solar radiation (Rn), air temperature (Ta), vapour pressure deficit (VPD), wind speed (Ws) relative humidity (RH) and precipitation (P) were simultaneously measured at a meteorological station on site. Results indicated that Js varied regularly during the diurnal and seasonal term. The nocturnal Js was substantial, with a seasonal variation similar to the patterns of daytime Js. The magnitude of Js changed considerably between sunny and rainy days. Redundancy (RDA) and Kendall's tau analysis suggested that daily Js in large plants was more sensitive to environmental factors, and the variation in daily Js during the growing season could be described by a multiple linear regression against environmental variables including Ta, VPD, Ws, RH, ST, and SoilG. While the nocturnal Js in smaller plants was more sensitive to meteorological factors. Ta, VPD, and Ws were significantly correlated with nighttime Js. The hourly nighttime sap flow rate of H. scoparium corresponded closely to Ta and VPD following a non-linear pattern. The results of this study can be used to estimate the transpiration of H. scoparium. PMID:26136229

  6. Spatial distribution of an ancient agricultural oasis in Juyan, northwestern China

    NASA Astrophysics Data System (ADS)

    Hu, Ningke; Li, Xin

    2014-09-01

    Activities related to agricultural cultivation are some of the major human drivers of landscape change on the Earth's surface. Archaeological remains can provide qualitative evidence for studies of past agricultural development and environmental conditions. The ancient Juyan Oasis, which once flourished along the historic Silk Road, was a typical oasis of downstream inland river basins in the arid zone of northwestern China. Historical records and archaeological discoveries have qualitatively shown that the oasis supported extensive agricultural activities in this historical period from the Han Dynasty to the early Ming Dynasty (B.C. 202-A.D. 1375), which can be traced back to 2,000 years ago. In this study, different types of archaeological remains (including archaeological sites, ground surface artifacts, ancient cultivation ruins, and agricultural irrigation canals) that were obtained and identified from previous archaeological reports, field inspections, and remote sensing imagery were used to determine the spatial extent of the agricultural oasis in the historical period of interest. Our approach used multiple data sources in order to increase the accuracy and reliability of the results compared to previous studies. Our results distinctly suggested that much of the oasis was cultivated during the historical periods considered. Additionally, the arable land area in the historical period considered was roughly estimated to be approximately (3.39-4.75) × 104 ha. These findings regarding the spatial distribution of this ancient agricultural oasis and its arable land were reasonably determined to represent the ancient agricultural development that occurred in the Juyan Oasis better than results obtained from single sources of data.

  7. The origin and formation model of Permian dolostones on the northwestern margin of Junggar Basin, China

    NASA Astrophysics Data System (ADS)

    Lu, Xinchuan; Shi, Ji'an; Zhang, Shuncun; Zou, Niuniu; Sun, Guoqiang; Zhang, Shengyin

    2015-06-01

    This study investigates the mechanism of dolostone formation and establishes a dolomitization model in the Permian strata on the northwestern margin of Junggar Basin, China. Dolomitic rock samples are collected from the Permian Fengcheng Formation in Urho area and then characterized by petrological, mineralogical, carbon and oxygen isotope, and trace element geochemical analyses. Results show that the major types of dolomitic rocks include dolomitic mudstone, dolomitic siltstone, dolomitized tuffaceous siltstone, and dolomitized tuffaceous mudstone. The dolomitized rocks are dominated by euhedral or subhedral powder- and fine-crystal dolomites formed by replacement lacustrine argilla-calcareous and siliceous (tuffaceous) components and commonly filled with residual and late calcite cements. The parameters of dolomitic rocks show great variations, including the V/Ni ratio (1.02-4.88), Sr content (95.9-783.6 μg/g), Mg/Ca ratio (0.68-5.13), degree of ordering (0.39-1.00), δ18OPDB (-14.8‰ to 3.2‰), and δ13CPDB (-1‰ to 5.2‰). The dolomitic rocks have multi-stage origins and were formed in a semi-closed continental brackish-saltwater bay with weak hydrodynamic processes, deep water bodies, and relatively quiet conditions. In the Permian depositional stage, a combination of complex tectonic activities, fault development, hot subtropical climate, and frequent volcanic activities provided not only Mg2+ source for dolomitization but also channels for rapid flow and seepage of Mg-rich fluids. The origins of dolostones in the study area include penecontemporaneous dolomitization, burial dolomitization, and hydrothermal dolomitization. This study lays a foundation for further studies on dolomite formation and dolomite reservoir, and provides effective methods for researching complex dolostone (tuffaceous, shale and silty dolomite) formation.

  8. The relationship between vegetation and groundwater in the hyper-arid Ejina Delta of northwestern China

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Yu, J.; Wang, P.; Xu, Y.

    2014-12-01

    Vegetation in the hyper-arid Ejina Delta of northwestern China plays irreplaceable role in preventing desertification and maintaining sustainable development in inland Heihe river basin . The groundwater mainly recharged by Heihe river provides the main water source for the vegetation survival in Ejina Delta. While due to extensive water use in mid and upper stream for local economic development, the Ejina Delta had experienced long-term no flow coming in each year and result in groundwater table great decline, which further lead to severely vegetation degradation during the 1990s. Ecological water allocation therefore was implemented in several arid inland basins to prevent ecological degradation. In order to wisely allocating water for ecological use, the relationship between vegetation and groundwater needs to be well understood, that is the aim of this paper. With the GMS software package, a groundwater flow model for the Ejina oasis was established and the spatial distributions of groundwater dynamics during 2000-2011 were simulated. Combing annual average groundwater table and NDVI during growing season on a per-pixel base, it was found that vegetation grew well and had a high biomass when the groundwater was in 1.5-3.8m and vegetation showed the best when the groundwater was about 2m. Further studies conducted at some locations with long-term ground water monitoring showed that when the groundwater table depth was more than 5 and 6 m, the vegetation conditions did not show an obvious response to groundwater table fluctuations; when the groundwater fluctuated between the proper intervals mentioned above, the correlation between vegetation condition and groundwater table were remarkably spatially heterogeneous. This result indicated that future ecological water allocation should consider more spatial heterogeneity of vegetation response to water environment for efficiently using the limited water.

  9. Crustal and uppermost mantle velocity structure beneath northwestern China from seismic ambient noise tomography

    NASA Astrophysics Data System (ADS)

    Li, Hongyi; Li, S.; Song, X. D.; Gong, M.; Li, X.; Jia, J.

    2012-01-01

    In this paper, we conduct ambient noise seismic tomography of northwestern China and adjacent regions. The data include 9 months (2009 January to 2009 September) three-component continuous data recorded at 146 seismic stations of newly upgraded China Provincial Digital Seismic Networks and regional Kyrgyzstan and Kazakhstan networks. Empirical Rayleigh and Love wave Green's functions are obtained from interstation cross-correlations. Group velocity dispersion curves for both Rayleigh and Love waves between 7 and 50 s periods were measured for each interstation path by applying the multiple-filter analysis method with phase-matched processing. The group velocity maps show clear lateral variations which correlate well with major geological structures and tectonic units in the study region. Shear wave velocity structures are inverted from Rayleigh wave and love wave dispersion maps. The results show that the Tibetan Plateau has a very thick crust with a low-velocity zone in its mid-lower crust. Along the northern margin of the plateau where a steep topographic gradient is present, the low-velocity zone does not extend to the Tarim basin which may indicate that crustal materials beneath the Tarim basin are colder and stronger than beneath the plateau, therefore inhibit the extension of mid-lower crustal flow and deformation of the Tibetan Plateau, resulting in very sharp topography contrasts. In the northeastern margin with a gentle topographic gradient toward the Ordos platform, the low-velocity zone diminishes around the eastern KunLun fault. Meanwhile, our results reveal obvious lateral velocity changes in the crust beneath the Tarim basin. In the upper crust, the Manjaer depression in the eastern Tarim basin is featured with very low velocities and the Bachu uplift in the western Tarim basin with high velocities; in the mid-lower crust, the northern Tarim basin in general displays lower velocities than the southern part along latitude ˜40° N with an east

  10. The effects of urbanization on temperature trends in different economic periods and geographical environments in northwestern China

    NASA Astrophysics Data System (ADS)

    Fang, Feng; Guo, Junqin; Sun, Landong; Wang, Jing; Wang, Xinping

    2014-04-01

    Using data collected from 22 urban and 65 rural meteorological stations in northwestern China between 1961 and 2009, this paper presents a study concerning the effects of urbanization on air temperature trends. To distinguish among the potential influences that stem from the economic development levels, population scales, and geographic environments of the cities in this region, the 49-year study period was divided into two periods: a period of less economic development, from 1961 to 1978, and a period of greater economic development, from 1979 to 2009. Each of the cities was classified as a megalopolis, large, or medium-small, depending on the population, and each was classified as a plateau, plain, or oasis city, depending on the surrounding geography. The differences in the air temperature trends between cities and the average of their rural counterparts were used to examine the warming effects of urbanization. The results of this study indicate that the magnitude of warming effects due to urbanization depends not only on a city's economic level, but also on the population scale and geographic environment of the city. The urbanization of most cities in northwestern China resulted in considerable negative warming effects during 1961-1978 but evidently positive effects during 1979-2009. The population scale of a city represents a significant factor: a city with a larger population has a stronger warming influence, regardless of whether the effect is negative or positive. Among the three geographic environments of the cities considered, plateaus and plains more significantly enhance warming effects than oases. The urban population trend has a very significant logarithm relationship with the urban temperature effect, but no clear relationships between urban temperature effects and city elevation were detected. The majority of the temperature trends, accounting for more than 60 % of the trends during 1961-2009, can be explained by natural factors, although

  11. Changes in Remotely Sensed Vegetation Growth Trend in the Heihe Basin of Arid Northwestern China.

    PubMed

    Sun, Wenchao; Song, Hao; Yao, Xiaolei; Ishidaira, Hiroshi; Xu, Zongxue

    2015-01-01

    The Heihe River Basin (HRB) is the second largest inland river basin in China, characterized by high diversity in geomorphology and irrigated agriculture in middle reaches. To improve the knowledge about the relationship between biotic and hydrological processes, this study used Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (NDVI) data (1982-2006) to analyze spatiotemporal variations in vegetation growth by using the Mann-Kendall test together with Sen's slope estimator. The results indicate that 10.1% and 1.6% of basin area exhibit statistically significant (p < 0.05) upward and downward trends, and maximum magnitude is 0.066/10a and 0.026/10a, respectively. More specifically, an increasing trend was observed in the Qilian Mountains and Hexi Corridor and a decreasing trend detected in the transitional region between them. Increases in precipitation and temperature may be one possible reason for the changes of vegetation growth in the Qilian Mountains. And decreasing trend in transitional region may be driven by the changes in precipitation. Increases of irrigation contribute to the upward trend of NDVI for cropland in the Hexi Corridor, reflecting that agricultural development becomes more intensive. Our study demonstrates the complexity of the response of vegetation growth in the HRB to climate change and anthropogenic activities and correspondingly adopting mechanistic ecological models capable of describing both factors is favorable for reasonable predictions of future vegetation growth. It is also indicated that improving irrigation water use efficiency is one practical strategy to balance water demand between human and natural ecosystems in the HRB. PMID:26284656

  12. Changes in Remotely Sensed Vegetation Growth Trend in the Heihe Basin of Arid Northwestern China

    PubMed Central

    Yao, Xiaolei; Ishidaira, Hiroshi; Xu, Zongxue

    2015-01-01

    The Heihe River Basin (HRB) is the second largest inland river basin in China, characterized by high diversity in geomorphology and irrigated agriculture in middle reaches. To improve the knowledge about the relationship between biotic and hydrological processes, this study used Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (NDVI) data (1982–2006) to analyze spatiotemporal variations in vegetation growth by using the Mann—Kendall test together with Sen’s slope estimator. The results indicate that 10.1% and 1.6% of basin area exhibit statistically significant (p < 0.05) upward and downward trends, and maximum magnitude is 0.066/10a and 0.026/10a, respectively. More specifically, an increasing trend was observed in the Qilian Mountains and Hexi Corridor and a decreasing trend detected in the transitional region between them. Increases in precipitation and temperature may be one possible reason for the changes of vegetation growth in the Qilian Mountains. And decreasing trend in transitional region may be driven by the changes in precipitation. Increases of irrigation contribute to the upward trend of NDVI for cropland in the Hexi Corridor, reflecting that agricultural development becomes more intensive. Our study demonstrates the complexity of the response of vegetation growth in the HRB to climate change and anthropogenic activities and correspondingly adopting mechanistic ecological models capable of describing both factors is favorable for reasonable predictions of future vegetation growth. It is also indicated that improving irrigation water use efficiency is one practical strategy to balance water demand between human and natural ecosystems in the HRB. PMID:26284656

  13. Mountains

    SciTech Connect

    Fuller, M.

    1989-01-01

    This book covers the following topics: Above the forest: the alpine tundra; Solar energy, water, wind and soil in mountains; Mountain weather; Mountain building and plate tectonics; Mountain walls: forming, changing, and disappearing; Living high: mountain ecosystems; Distribution of mountain plants and animals; On foot in the mountains: how to hike and backpack; Ranges and peaks of the world. Map and guidebook sources, natural history and mountain adventure trips, mountain environmental education centers and programs, and sources of information on trails for the handicapped are included.

  14. [Environmental significance of wet deposition composition in the central Qilian Mountains, China].

    PubMed

    Li, Zong-jie; Li, Zong-xing; Tian, Qing; Song, Ling-ling; Jia, Bing; Guo, Rui; Song, Yao-xuan; Su, Suo-nan; Han, Chun-tan

    2014-12-01

    A total of 90 precipitation samples were collected from individual precipitation events at the Qilian Alpine Ecology & Hydrology Research Station (Hulugou Station, 30 degrees 47'N, 90 degrees 58'E; 3 260 m a. s. l) located in the central Qilian Mountains from August 2012 to November 2013. All samples were analyzed for major cations (Na, K+, Ca2+ and Mg2+), anions (Cl- , NO3- and SO4(2-)) and conductivity. Precipitation EC values ranged from 2.26 to 482 μS x cm(-1) with an average value of 41.9 μS x cm(-1). The precipitation was of SO4(2-) -Mg(2+) -Ca2+ type, which contributed > 70% to the total ionic concentration. The same as the precipitation alkalinity, precipitation events occurred around summer showed lower concentrations, while it had higher concentrations in winter and spring with little precipitation and larger wind speed. Enrichment factor (EF), correlation and factor analysis indicated that regional crustal aerosols and species from central Asian and northwestern China arid regions brought by the westerly circulation were the major sources for these ions, some dust from human pollution were the secondary sources, and the contribution of sea salt was the least due to the long distance transport. These characteristics could be also confirmed by the correlation between ionic concentrations and metrological data in the study region. It is also interesting that the precipitation chemistry was different under the different atmospheric circulation: the monsoon precipitation, the interaction precipitation events ( influenced both by monsoon and westerly) and the westerly precipitation.

  15. Paleocene-Early Eocene uplift of the Altyn Tagh Mountain: Evidence from detrital zircon fission track analysis and seismic sections in the northwestern Qaidam basin

    NASA Astrophysics Data System (ADS)

    Wang, Yadong; Zheng, Jianjing; Zheng, Youwei; Liu, Xingwang; Sun, Guoqiang

    2015-12-01

    Most existing tectonic models suggest that the deformation and uplift of the northern Tibetan Plateau is the latest crustal response to the collision of the India Plate and Eurasian Plate. The tectonic evolution of Altyn Tagh Mountain (hereafter called simply the "Altyn Tagh"), on the northern margin of the Tibetan Plateau, has attracted considerable scientific attention. In this study, we use fission track age dates of detrital zircons from the northwestern Qaidam basin together with sedimentary observations to understand more fully the Cenozoic tectonic uplift of the Altyn Tagh. Detrital zircons from five borehole samples distributed in different folds in the northwestern Qaidam basin yielded ages mainly ranging from 88.5 to 49.2 Ma, older than their sedimentary deposition ages (43.8-22 Ma). The binomial distribution in grain age fitted peaks was generally dominated by one young peak, P1, which varied from 73.6 to 47.2 Ma. A thinning of the Cenozoic Lulehe Formation (53.5-43.8 Ma) stretched from the inner Qaidam basin to the slopes of the Altyn Tagh in the seismic sections of the northwestern Qaidam basin. Based on magnetostratigraphic dating, there was a hiatus in sedimentation in the Qaidam basin between 65 Ma and 54 Ma; this was confirmed by seismic profiles and borehole data, which show an unconformity between the Mesozoic Quanyagou Formation and the Lulehe Formation. Combined with an analysis of provenance, the detrital zircon young peak age and the sedimentary record revealed that the most significant regional uplift of the Altyn Tagh occurred during the Paleogene-Early Eocene, almost coinciding with the collision of the Indian and Eurasian plates between 65 Ma and 44 Ma.

  16. Weathering characteristics of the Lower Paleozoic black shale in northwestern Guizhou Province, south China

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Zhang, Jinchuan; Tang, Xuan; Yang, Chao; Tang, Shuai

    2016-07-01

    The northwestern Guizhou in the Yangtze Craton of south China has a tremendous potential of shale gas resource. In this paper, we present results from major and trace elements, total organic carbon, mineralogical composition analysis and petrophysical parameters to characterise shale weathering features. Further, the differences of black shale between underground and outcrops have also been presented to examine the changes of black shale after weathering. Our results show that the trace elements of shale have varying degrees of loss in the weathering leaching process, both in Niutitang shale and Longmaxi shale, the loss of B, V, Ni, Cu, Zn and Ba is obvious, but the element migration quantity in the former is greater than in the latter. Decomposition of minerals such as pyrite, feldspar and calcite result in the leaching of Na, Ca, Mg and Fe. The loss rate of total organic carbon (TOC) in black shales ranges from 18% to 70% with an average of 43%; moreover, the loss of organic carbon in samples with high TOC content is larger than in those samples with low TOC content. Results following the testing of porosity and permeability show that porosity increases significantly after weathering but permeability changes little. Furthermore, the increment of porosity is greater in the Niutitang shale (with more sulphide minerals) than in the Longmaxi shale, suggesting that the oxidation of sulphide minerals may have led to the formation of an acidic environment, causing the other minerals in the black shale to weather more quickly, thus resulting in increased porosity. The content of clay minerals in the core samples is slightly lesser than the outcrop samples, but the TOC content in the core samples is greater and has a larger specific surface area. This suggest that the TOC content played a decisive role on the specific surface area of shale. In addition, changes in the black shale caused by the weathering process mainly depend on the mineral composition and the TOC content

  17. Characterization of Methicillin-Resistant and -Susceptible Staphylococcal Isolates from Bovine Milk in Northwestern China

    PubMed Central

    Li, Longping; Zhou, Luoxiong; Wang, Lihong; Xue, Huping; Zhao, Xin

    2015-01-01

    Emergence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) in bovine milk is a major public health concern. The primary purpose of this research was to determine molecular genetic characteristics and antibiotic resistance of staphylococcal isolates recovered from milk of mastitic cows in the Shaanxi Province in Northwestern China. One hundred and thirteen methicillin-susceptible Staphylococcus aureus (MSSA), one mecA-positive and phenotype-positive MRSA, seven mecA- and mecC- negative but phenotype-positive MRSA and two MR-CoNS including one oxacillin-susceptible mecA-positive Staphylococcus haemolyticus (OS-MRSH) and one mecA-positive and methicillin-resistant Staphylococcus epidermidis (MRSE) isolates were recovered from 214 quarter milk samples on 4 dairy farms. All above 123 isolates were subjected to antibiotic resistance profiling. S. aureus isolates were also genotyped using the spa typing and the multilocus sequence typing (MLST). Eight MRSA and 2 MR-CoNS isolates were additionally tested for SCCmec types. Resistance was common among isolates against ampicillin or penicillin (80.5%), kanamycin (68.3%), gentamicin (67.5%), tetracycline (43.9%) and chloramphenicol (30.1%). However, no isolate was resistant to vancomycin or teicoplanin. Twenty, 29 and 58 isolates showed resistance to 1, 2 or more than 2 antibiotics, respectively. The predominant multidrug resistance profile was penicillin/ampicillin/kanamycin/gentamicin/tetracycline (46 isolates). Most S. aureus isolates belonged to spa types t524 (n = 63), t11772 (a new type, n = 31) and t4207 (n = 15). At the same time, MLST types ST71 (n = 67) and ST2738 (a new type, n = 45) were identified as dominant sequence types. The mecA-positive and phenotype-positive MRSA isolate had a composite genotype t524-ST71-SCCmecIVa, while 7 mecA-negative but phenotype-positive MRSA isolates were all t524-ST71. The OS-MRSH isolate contained a type V

  18. Characterization of methicillin-resistant and -susceptible staphylococcal isolates from bovine milk in northwestern china.

    PubMed

    Li, Longping; Zhou, Luoxiong; Wang, Lihong; Xue, Huping; Zhao, Xin

    2015-01-01

    Emergence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) in bovine milk is a major public health concern. The primary purpose of this research was to determine molecular genetic characteristics and antibiotic resistance of staphylococcal isolates recovered from milk of mastitic cows in the Shaanxi Province in Northwestern China. One hundred and thirteen methicillin-susceptible Staphylococcus aureus (MSSA), one mecA-positive and phenotype-positive MRSA, seven mecA- and mecC- negative but phenotype-positive MRSA and two MR-CoNS including one oxacillin-susceptible mecA-positive Staphylococcus haemolyticus (OS-MRSH) and one mecA-positive and methicillin-resistant Staphylococcus epidermidis (MRSE) isolates were recovered from 214 quarter milk samples on 4 dairy farms. All above 123 isolates were subjected to antibiotic resistance profiling. S. aureus isolates were also genotyped using the spa typing and the multilocus sequence typing (MLST). Eight MRSA and 2 MR-CoNS isolates were additionally tested for SCCmec types. Resistance was common among isolates against ampicillin or penicillin (80.5%), kanamycin (68.3%), gentamicin (67.5%), tetracycline (43.9%) and chloramphenicol (30.1%). However, no isolate was resistant to vancomycin or teicoplanin. Twenty, 29 and 58 isolates showed resistance to 1, 2 or more than 2 antibiotics, respectively. The predominant multidrug resistance profile was penicillin/ampicillin/kanamycin/gentamicin/tetracycline (46 isolates). Most S. aureus isolates belonged to spa types t524 (n = 63), t11772 (a new type, n = 31) and t4207 (n = 15). At the same time, MLST types ST71 (n = 67) and ST2738 (a new type, n = 45) were identified as dominant sequence types. The mecA-positive and phenotype-positive MRSA isolate had a composite genotype t524-ST71-SCCmecIVa, while 7 mecA-negative but phenotype-positive MRSA isolates were all t524-ST71. The OS-MRSH isolate contained a type V

  19. Green Auctions and Reduction of Information Rents in Payments for Environmental Services: An Experimental Investigation in Sunan County, Northwestern China

    PubMed Central

    Deng, Xiaohong; Xu, Zhongmin

    2015-01-01

    Reducing information rents is an important task for government agencies wishing to purchase maximal environmental services with limited budgets. This paper reports on several green auction options for reducing information rents and improving the performance of the “Grain for Green” Payments for environmental services (PES) program implemented in northwestern China. In r experimental auctions and investigations, door-to-door interviews were conducted and bidding envelopes and survey questionnaires were used to determine the offers and the foregone profits of the participants. Three scenarios are analyzed in this paper: a uniform price auction, a discriminatory price auction, and an opportunity-cost system. The results show that compared to the uniform price auction system, the other auction systems can increase the cost-effectiveness of conservation contracting. Competitive bidding can reveal true opportunity costs and can reduce information rents extracted from the government by farmers using private information. The demographics and average bids of these auction types were also analyzed. “Perfect information” in the opportunity-cost offer system has the best performance but is very hard to implement in reality. The results of this research show that the auction is a valuable tool for purchasing conservation contracts in northwestern China, but that in the future, the performance of these auctions should be studied with relaxed model assumptions. PMID:25793263

  20. Seroprevalence of Chlamydia psittaci infection in market-sold adult chickens, ducks and pigeons in north-western China.

    PubMed

    Cong, W; Huang, S Y; Zhang, X Y; Zhou, D H; Xu, M J; Zhao, Q; Song, H Q; Zhu, X Q; Qian, A D

    2013-08-01

    Chlamydia psittaci, the agent of psittacosis in humans, infects a wide range of avian species. To assess the risk of psittacosis posed by domestic birds in the urban environment, the prevalence of C. psittaci antibodies in 413 chickens (Gallus domesticus; 305 caged and 108 free-range), 334 ducks (Anas spp.; 111 caged and 223 free-range) and 312 pigeons (Columba livia) in Lanzhou, north-western China, was detected using the indirect haemagglutination assay. The specific antibodies were found in sera of 55 (13.32 %) chickens, 130 (38.92 %) ducks and 97 (31.09 %) pigeons. Statistical analysis showed that the seroprevalence of C. psittaci infection in chickens was significantly lower than that in ducks and pigeons (P<0.05). The C. psittaci seroprevalence in caged and free-range chickens was 7.54 % and 29.63 %, respectively, and the difference was statistically significant (P<0.05). The C. psittaci seroprevalence in caged and free-range ducks was 26.13 % and 45.29 %, respectively (P<0.05). To our knowledge, this is the first study indicating the presence of C. psittaci infection in market-sold chickens, ducks and pigeons in north-western China. Close contact with these birds is associated with a risk of zoonotic transmission of C. psittaci. Public education should be implemented to reduce the risk of avian to human transmission of such a pathogenic agent.

  1. Green auctions and reduction of information rents in payments for environmental services: an experimental investigation in Sunan County, northwestern China.

    PubMed

    Deng, Xiaohong; Xu, Zhongmin

    2015-01-01

    Reducing information rents is an important task for government agencies wishing to purchase maximal environmental services with limited budgets. This paper reports on several green auction options for reducing information rents and improving the performance of the "Grain for Green" Payments for environmental services (PES) program implemented in northwestern China. In r experimental auctions and investigations, door-to-door interviews were conducted and bidding envelopes and survey questionnaires were used to determine the offers and the foregone profits of the participants. Three scenarios are analyzed in this paper: a uniform price auction, a discriminatory price auction, and an opportunity-cost system. The results show that compared to the uniform price auction system, the other auction systems can increase the cost-effectiveness of conservation contracting. Competitive bidding can reveal true opportunity costs and can reduce information rents extracted from the government by farmers using private information. The demographics and average bids of these auction types were also analyzed. "Perfect information" in the opportunity-cost offer system has the best performance but is very hard to implement in reality. The results of this research show that the auction is a valuable tool for purchasing conservation contracts in northwestern China, but that in the future, the performance of these auctions should be studied with relaxed model assumptions.

  2. Pre-, syn-, and postcollisional stratigraphic framework and provenance of upper triassic-upper cretaceous strata in the northwestern talkeetna mountains, alaska

    USGS Publications Warehouse

    Hampton, B.A.; Ridgway, K.D.; O'Neill, J. M.; Gehrels, G.E.; Schmidt, J.; Blodgett, R.B.

    2007-01-01

    Mesozoic strata of the northwestern Talkeetna Mountains are located in a regional suture zone between the allochthonous Wrangellia composite terrane and the former Mesozoic continental margin of North America (i.e., the Yukon-Tanana terrane). New geologic mapping, measured stratigraphic sections, and provenance data define a distinct three-part stratigraphy for these strata. The lowermost unit is greater than 290 m thick and consists of Upper Triassic-Lower Jurassic mafic lavas, fossiliferous limestone, and a volcaniclastic unit that collectively we informally refer to as the Honolulu Pass formation. The uppermost 75 m of the Honolulu Pass formation represent a condensed stratigraphic interval that records limited sedimentation over a period of up to ca. 25 m.y. during Early Jurassic time. The contact between the Honolulu Pass formation and the overlying Upper Jurassic-Lower Cretaceous clastic marine strata of the Kahiltna assemblage represents a ca. 20 m.y. depositional hiatus that spans the Middle Jurassic and part of Late Jurassic time. The Kahiltna assemblage may to be up to 3000 m thick and contains detrital zircons that have a robust U-Pb peak probability age of 119.2 Ma (i.e., minimum crystallization age/maximum depositional age). These data suggest that the upper age of the Kahiltna assemblage may be a minimum of 10-15 m.y. younger than the previously reported upper age of Valanginian. Sandstone composition (Q-43% F-30% L-27%-Lv-71% Lm-18% Ls-11%) and U-Pb detrital zircon ages suggest that the Kahiltna assemblage received igneous detritus mainly from the active Chisana arc, remnant Chitina and Talkeetna arcs, and Permian-Triassic plutons (Alexander terrane) of the Wrangellia composite terrane. Other sources of detritus for the Kahiltna assemblage were Upper Triassic-Lower Jurassic plutons of the Taylor Mountains batholith and Devonian-Mississippian plutons; both of these source areas are part of the Yukon-Tanana terrane. The Kahiltna assemblage is overlain

  3. Observations of flow variability through the Kerama Gap between the East China Sea and the Northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Na, Hanna; Wimbush, Mark; Park, Jae-Hun; Nakamura, Hirohiko; Nishina, Ayako

    2014-02-01

    The Kerama Gap, near the middle of the Ryukyu Island chain, is the deepest channel with a sill depth of 1050 m connecting the East China Sea (ECS) to the Northwestern Pacific. We measured the flow through the Kerama Gap from June 2009 to June 2011. The 2 year mean transport, 2.0 ± 0.7 Sv, is into the ECS from the Northwestern Pacific; it contributes about 11% of the mean Kuroshio transport in the ECS at the PN line. Subtidal standard deviation of the transport through the Kerama Gap is 3.2 Sv, comparable to that of the PN-line Kuroshio transport (4.0 Sv), suggesting a significant effect of Kerama Gap transport on temporal variability of the Kuroshio transport in the ECS. Comparison with time series of satellite-measured sea surface height maps reveals that temporal variability of the Kerama Gap transport is related to the arrival of mesoscale eddies from the east: high (low) transport into the ECS is associated with the presence of a cyclonic (anticyclonic) eddy south of the Kerama Gap.

  4. Misty Mountains and Mountain Movers: Using Art and Literature in Teaching About Old and New China.

    ERIC Educational Resources Information Center

    Haimes, Barbara

    These learning activities can be used to show secondary level students how contemporary art and literature reflect the main trends of thought and values of the People's Republic of China. Students learn about two of the most important philosophies in old China--Confucianism and Taoism. They also learn about new China (China since 1949). Students…

  5. [Detection of the Siberian Tick-borne Encephalitis Virus in the Xinjiang Uygur Autonomous Region, northwestern China].

    PubMed

    Liu, Ran; Zhang, Guilin; Liu, Xiaoming; Li, Yuchang; Zheng, Zhong; Sun, Xiang; Yang, Yinhui

    2016-01-01

    Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.

  6. Northwestern China: a place to learn more on oesophageal cancer. Part one: behavioural and environmental risk factors.

    PubMed

    Zheng, Shutao; Vuitton, Lucine; Sheyhidin, Ilyar; Vuitton, Dominique Angèle; Zhang, Yueming; Lu, Xiaomei

    2010-08-01

    Oesophageal squamous cell carcinoma (OSCC) remains a public health problem in many countries, especially in emerging and developing countries. Epidemiology of OSCC is characterized by marked differences in prevalence between countries/regions/ethnical groups. The highest incidence in the world is reached by populations living in specific areas of northwestern Xinjiang, China where age-adjusted mortality may reach 150 of 100 000. In fact, there are also marked differences among the various geographical areas and the various ethnic groups within the region, which suggests specific risk factors. Behavioural factors include those factors which are common to all 'high-risk populations', such as tobacco smoking and alcohol drinking. However, the very unusual sex ratio (1.2 : 1.0) and young age range of OSCC occurrence suggests the involvement of additional early risk factors shared by males and females, and which are different from those studied in other 'high-risk' areas of the world, including China, such as LinXian area. These include drinking very hot and salted tea, boiled with milk; a diet rich in meat, especially salted, dry and/or smoked meat, and dairy products; and a diet poor in fresh fruit and vegetables. The combination of hot drinks (such as milk, tea and soups) and high-degree spirit drinks, and hard food (bread, meat and cheese), together with poor oral hygiene and tooth loss, is likely to add mechanical injury of the oesophagus to other factors linked to climate characteristics of the area (drought) and dietary habits, which promote a sodium and nitrosamine-rich diet. Association of early and severe hypertension in the same populations at high risk of OSCC might likely raise more attention. Human papilloma virus (HPV) infection, and especially HPV 16/18 E6/E7, with gene mutations and association with p53 overexpression, may contribute to the extremely high incidence of OSCC observed in Xinjiang, and could be accessible to prevention. Infection may

  7. Greenhouse Gas Emissions from Cotton Field under Different Irrigation Methods and Fertilization Regimes in Arid Northwestern China

    PubMed Central

    Guo, Wei; Feng, Jinfei; Li, Lanhai; Yang, Haishui; Wang, Xiaohua; Bian, Xinmin

    2014-01-01

    Drip irrigation is broadly extended in order to save water in the arid cotton production region of China. Biochar is thought to be a useful soil amendment to reduce greenhouse gas (GHG) emissions. Here, a field study was conducted to compare the emissions of nitrous oxide (N2O) and methane (CH4) under different irrigation methods (drip irrigation (D) and furrow irrigation (F)) and fertilization regimes (conventional fertilization (C) and conventional fertilization + biochar (B)) during the cotton growth season. The accumulated N2O emissions were significantly lower with FB, DC, and DB than with FC by 28.8%, 36.1%, and 37.6%, while accumulated CH4 uptake was 264.5%, 226.7%, and 154.2% higher with DC, DB, and FC than that with FB, respectively. Irrigation methods showed a significant effect on total global warming potential (GWP) and yield-scaled GWP (P < 0.01). DC and DB showed higher cotton yield, water use efficiency (WUE), and lower yield-scaled GWP, as compared with FC and FB. This suggests that in northwestern China mulched-drip irrigation should be a better approach to increase cotton yield with depressed GHG. In addition, biochar addition increased CH4 emissions while it decreased N2O emissions. PMID:25133229

  8. [Polypore species diversity, floral composition, and distribution characteristics in Changbai Mountains, Northeast China].

    PubMed

    Wei, Yu-lian

    2011-10-01

    Polypore is an important group of wood-rotting fungi, which can decompose wood cellulose, semi-cellulose, and lignin into nutrients to be utilized by itself and other organisms, and accordingly, can promote the material cycling in forest ecosystem. Based on more than 10 years investigation and collection, it was found that the polypore in Changbai Mountains was rich in species diversity, with the Shannon diversity index being 5.06. In the Mountains, a total of 246 polypore species were recorded, occupying 40.7% of the total in China. The polypore species recorded belonged to 80 genera, 11 families, and 6 orders, among which, Polyporaceae was the dominant family. The most important bio-geographical elements of the polypore in Changbai Mountains were north temperate element and cosmopolitan element, other elements also included, showing a distinct north temperate character in floral composition. Pinus was the main host of polypore, supporting 41.5% of the polypore in Changbai Mountains. Most of the polypore was saprophytic, and its quantity had a significant correlation with the decaying degree of substrates, implying its important role in the material cycling in forest ecosystem in Changbai Mountains. There were 18 threatened polypore species in the Mountains, accounting for 37.5% of total in China. Besides their important ecological functions, many of the polypore also had higher economic value. On the premise of complete protection on them, these fungal resources should be exploited reasonably.

  9. Three new spider species of the genus Pholcus from the Taihang Mountains of China (Araneae, Pholcidae)

    PubMed Central

    Zhang, Bao-Shi; Zhang, Feng; Liu, Jing-Ze

    2016-01-01

    Abstract In this study, three new species belonging to the genus Pholcus, collected from a forest of the Taihang Mountains, P. R. China, are described under the names of Pholcus papillatus sp. n. (male, female), Pholcus curvus sp. n. (male, female) and Pholcus auricularis sp. n. (male, female). PMID:27408600

  10. Five new species of Phintella Strand, 1906 (Araneae, Salticidae) from the Wuling Mountains, China

    PubMed Central

    Huang, Yi; Wang, Cheng; Peng, Xian-Jin

    2015-01-01

    Abstract Five new species of Phintella are described from the Wuling Mountains, China: Phintella arcuata sp. n. (male and female), Phintella levii sp. n. (female), Phintella panda sp. n. (female), Phintella pulcherrima sp. n. (male and female), and Phintella wulingensis sp. n. (female). Distribution data, detailed morphological characteristics, and illustrations of body and genital organs are presented. PMID:26261431

  11. Ethnic and geographic variations in HPV prevalence and genotype distribution in north-western Yunnan, China.

    PubMed

    Baloch, Zulqarnain; Yuan, Tao; Wang, Binghui; Tai, Wenlin; Feng, Yue; Liu, Yanqing; Li, Xiao; Feng, Yue; Liu, Li; Zhang, A-mei; Wu, Xiaomei; Xia, Xueshan

    2016-03-01

    The prevalence and genotype distribution of human papillomavirus (HPV) vary throughout the world. To assess the prevalence and genotype distribution of HPV among three ethnic groups in two geographic locations in north-western Yunnan, we recruited 522 women in Shangri-le (n = 255) and Lijiang (n = 267). PCR amplification of HPV DNA was performed on cervical cells from these women using two consensus primer systems (MY09/11 and GP5/6). Amplified-HPV DNA was genotyped using the HPV GenoArray test. Geographically, the HPV prevalence was significantly higher (P = 0.002) among Shangri-le women than among Lijiang women. Infections with high-risk (HR)-HPV and with multiple HPV genotypes were also significantly more common (P = 0.001) among women in Shangri-le than women in Lijiang. Additionally, the prevalence of overall, HR-HPV, and single genotype HPV infections was significantly higher (P = 0.001) among Tibetan women than among Naxi and Han women. HPV-16 and HPV-33 were significantly more frequent in Shangri-le women compared with Lijiang (P = 0.006) women. In addition, HPV-16 (9.81%) and HPV-33 (5.88%) were significantly more prevalent in Tibetan women than in Naxi and Han women. Here, for the first time, we highlight the significant variation in the prevalence and genotype distribution of HPV in various populations in the north-western region of Yunnan Province.

  12. Two new species of Japalura (Squamata: Agamidae) from the Hengduan Mountain Range, China.

    PubMed

    Wang, Kai; Jiang, Ke; Zou, Da-Hu; Yan, Fang; Siler, Cameron D; Che, Jing

    2016-01-18

    Until recently, the agamid species, Japalura flaviceps, was recognized to have the widest geographic distribution among members of the genus occurring in China, from eastern Tibet to Shaanxi Province. However, recent studies restricted the distribution of J. flaviceps to the Dadu River valley only in northwestern Sichuan Province, suggesting that records of J. flaviceps outside the Dadu River valley likely represent undescribed diversity. During two herpetofaunal surveys in 2013 and 2015, eight and 12 specimens of lizards of the genus Japalura were collected from the upper Nujiang (=Salween) Valley in eastern Tibet, China, and upper Lancang (=Mekong) Valley in northwestern Yunnan, China, respectively. These specimens display a unique suite of diagnostic morphological characters. Our robust comparisons of phenotype reveal that these populations can be distinguished readily from J. flaviceps and all other recognized congeners. Herein, we describe the two Japalura lineages as new species, Japalura laeviventris sp. nov. and Japalura iadina sp. nov.. In addition, we provide updated conservation assessments for the new species as well as imperiled congeners according to the IUCN criteria for classification, discuss the importance of color patterns in the diagnosis and description of species in the genus Japalura, and discuss directions for future taxonomic studies of the group. PMID:26828033

  13. Two new species of Japalura (Squamata: Agamidae) from the Hengduan Mountain Range, China

    PubMed Central

    WANG, Kai; JIANG, Ke; ZOU, Da-Hu; YAN, Fang; ZOU, Da-Hu; Cameron, D.SILER; CHE, Jing

    2016-01-01

    Until recently, the agamid species, Japalura flaviceps, was recognized to have the widest geographic distribution among members of the genus occurring in China, from eastern Tibet to Shaanxi Province. However, recent studies restricted the distribution of J. flaviceps to the Dadu River valley only in northwestern Sichuan Province, suggesting that records of J. flaviceps outside the Dadu River valley likely represent undescribed diversity. During two herpetofaunal surveys in 2013 and 2015, eight and 12 specimens of lizards of the genus Japalura were collected from the upper Nujiang (=Salween) Valley in eastern Tibet, China, and upper Lancang (=Mekong) Valley in northwestern Yunnan, China, respectively. These specimens display a unique suite of diagnostic morphological characters. Our robust comparisons of phenotype reveal that these populations can be distinguished readily from J. flaviceps and all other recognized congeners. Herein, we describe the two Japalura lineages as new species, Japalura laeviventris sp. nov. and Japalura iadina sp. nov.. In addition, we provide updated conservation assessments for the new species as well as imperiled congeners according to the IUCN criteria for classification, discuss the importance of color patterns in the diagnosis and description of species in the genus Japalura, and discuss directions for future taxonomic studies of the group. PMID:26828033

  14. Two new species of Japalura (Squamata: Agamidae) from the Hengduan Mountain Range, China.

    PubMed

    Wang, Kai; Jiang, Ke; Zou, Da-Hu; Yan, Fang; Siler, Cameron D; Che, Jing

    2016-01-18

    Until recently, the agamid species, Japalura flaviceps, was recognized to have the widest geographic distribution among members of the genus occurring in China, from eastern Tibet to Shaanxi Province. However, recent studies restricted the distribution of J. flaviceps to the Dadu River valley only in northwestern Sichuan Province, suggesting that records of J. flaviceps outside the Dadu River valley likely represent undescribed diversity. During two herpetofaunal surveys in 2013 and 2015, eight and 12 specimens of lizards of the genus Japalura were collected from the upper Nujiang (=Salween) Valley in eastern Tibet, China, and upper Lancang (=Mekong) Valley in northwestern Yunnan, China, respectively. These specimens display a unique suite of diagnostic morphological characters. Our robust comparisons of phenotype reveal that these populations can be distinguished readily from J. flaviceps and all other recognized congeners. Herein, we describe the two Japalura lineages as new species, Japalura laeviventris sp. nov. and Japalura iadina sp. nov.. In addition, we provide updated conservation assessments for the new species as well as imperiled congeners according to the IUCN criteria for classification, discuss the importance of color patterns in the diagnosis and description of species in the genus Japalura, and discuss directions for future taxonomic studies of the group.

  15. Forest ecosystem services of changbai mountain in china.

    PubMed

    Wu, Gang; Xiao, Han; Zhao, Jingzhu; Shao, Guofan; Li, Jing

    2002-02-01

    The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method (PAM) with the value assessment method (VAM) to evaluate the forest ecosystem services of the northern slope of the, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38 x 10(12) yuan, of which, water conservation is 66%, water conservation and air purification together make up 80%, while the timber value is only 7%. Therefore, developing the ecosystem services besides timber is the best way to exert the integrated value of the forest ecosystem services of Changbai Mountain. PMID:18763060

  16. Forest ecosystem services of changbai mountain in china.

    PubMed

    Wu, Gang; Xiao, Han; Zhao, Jingzhu; Shao, Guofan; Li, Jing

    2002-02-01

    The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method (PAM) with the value assessment method (VAM) to evaluate the forest ecosystem services of the northern slope of the, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38 x 10(12) yuan, of which, water conservation is 66%, water conservation and air purification together make up 80%, while the timber value is only 7%. Therefore, developing the ecosystem services besides timber is the best way to exert the integrated value of the forest ecosystem services of Changbai Mountain.

  17. Changes in glacier extent and surface elevations in the Depuchangdake region of northwestern Tibet, China

    NASA Astrophysics Data System (ADS)

    Li, Zhiguo; Tian, Lide; Wu, Hongbo; Wang, Weicai; Zhang, Shuhong; Zhang, Jingjing; Li, Xuexin

    2016-01-01

    Remote sensing data, including those from Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM +), the Shuttle Radar Topography Mission Digital Elevation Model (SRTM4.1 DEM), and the Geoscience Laser Altimeter System Ice, Cloud, and Land Elevation Satellite (Glas/ICESat), show that from 1991 to 2013 the glacier area in the Depuchangdake region of northwestern Tibet decreased from 409 to 393 km2, an overall loss of 16 km2, or 3.9% of the entire 1991 glacial area. The mean glacier-thinning rate was - 0.40 ± 0.16 m equivalent height of water per year (w.e./yr), equating to a glacier mass balance of - 0.16 ± 0.07 km3 w.e./yr. Total mass loss from 2003 to 2009 was - 1.13 ± 0.46 km3. Glacier retreat likely reflects increases in annual total radiation, annual positive degree days, and maximum temperature, with concurrent increases in precipitation insufficient to replenish glacial mass loss. The rate of glacier retreat in Depuchangdake is less than that for Himalayan glaciers in Indian monsoon-dominated areas, but greater than that for Karakoram glaciers in mid-latitude westerly-dominated areas. Glacier type, climate zone, and climate change all impact on the differing degrees of long-term regional glacial change rate; however, special glacier distribution forms can sometimes lead to exceptional circumstances.

  18. Ovi-caprid dung as an indicator of paleovegetation and paleoclimate in northwestern China

    NASA Astrophysics Data System (ADS)

    Ghosh, Ruby; Gupta, Sudha; Bera, Subir; Jiang, Hong-en; Li, Xiao; Li, Cheng-Sen

    2008-09-01

    Diverse palynomorphs and phytoliths recovered from coprolites of ovi-caprids (sheep, goat) collected from Yang-Hai Tomb at Xinjiang Province, China, have been used to elucidate the dietary pattern of ancient livestock and to reconstruct the paleovegetation and paleoclimate of this part of northwest China ca. 2500 14C yr BP. Palynological and phytolith data suggest that a rich dry temperate vegetation prevailed in the area during the said period. Climatic conditions and grassland vegetation type of the area are explored using phytolith indices.

  19. Stoneflies of the genus Neoperla (Plecoptera, Perlidae) from Wuyi Mountain National Nature Reserve, Fujian of China

    PubMed Central

    Qin, Xue-Feng; Murányi, Dávid; Wang, Guo-Quan; Li, Wei-Hai

    2013-01-01

    Abstract The species of the genus Neoperla are reviewed from Wuyi Mountain National Nature Reserve located in the Fujian Province of southeastern China, including the description of a new species, Neoperla brevistyla sp. n. The new species is compared to similar taxa. The first records of five Neoperla species, Neoperla henana Li, Wu & Zhang, 2011, Neoperla similiserecta Wang & Li, 2012, Neoperla qingyuanensis Yang & Yang, 1995, Neoperla xuansongae Li & Li, 2013 and Neoperla tuberculata Wu, 1938 are given for the Wuyi Mountain. A provisional key is provided for facilitating the identification of these species. PMID:24039532

  20. Evolutionary History of a Desert Shrub Ephedra przewalskii (Ephedraceae): Allopatric Divergence and Range Shifts in Northwestern China

    PubMed Central

    Su, Zhi-Hao; Zhang, Ming-Li

    2016-01-01

    Based on two chloroplast DNA sequences, psbA-trnH and trnT-trnF, phylogeographical patterns of a desert shrub, Ephedra przewalskii, were examined across most of its geographic range in northwestern China. A total of sixteen haplotypes were detected. There was a common haplotype in each basin, that was haplotype A in Tarim Basin, haplotype G in Junggar Basin, and haplotype M in Qaidam Basin. Genetic variance mainly occurred among populations, geographic regions, and eleven geographic groups subdivided by SAMOVA analysis. E. przewalskii likely had a smaller and more fragmented geographic range during the Last Glacial Maximum, which was determined based on ecological niche modelling. Three groups of E. przewalskii populations were detected to have experience range expansion, and this was based on significant values of Fu’s FS, Tajima’s D, and unimodel mismatch distributions. The cold and dry climate during the glacial period of the Quaternary is postulated to have been a driver for significant genetic isolation and divergence among populations or groups in E. przewalskii, whereas the warmer and wetter climate during the interglacial period is speculated to have provided favourable conditions for range expansion of the species. PMID:27351630

  1. Triggering conditions and depositional characteristics of a disastrous debris flow event in Zhouqu city, Gansu Province, northwestern China

    NASA Astrophysics Data System (ADS)

    Tang, C.; Rengers, N.; van Asch, Th. W. J.; Yang, Y. H.; Wang, G. F.

    2011-11-01

    On 7 August 2010, catastrophic debris flows were triggered by a rainstorm in the catchments of the Sanyanyu and Luojiayu torrents, Zhouqu County, Gansu Province northwestern China. These two debris flows originated shortly after a rainstorm with an intensity of 77.3 mm h-1 and transported a total volume of about 2.2 million m3, which was deposited on an existing debris fan and into a river. This catastrophic event killed 1765 people living on this densely urbanised fan. The poorly sorted sediment contains boulders up to 3-4 m in diameter. In this study, the geomorphological features of both debris flow catchment areas are analyzed based on the interpretation of high-resolution remote sensing imagery combined with field investigation. The characteristics of the triggering rainfall and the initiation of the debris flow occurrence are discussed. Using empirical equations, the peak velocities and discharges of the debris flows were estimated to be around 9.7 m s-1 and 1358 m3 s-1 for the Sanyanyu torrent and 11 m s-1 and 572 m3 s-1 for the Luojiayu torrent. The results of this study contribute to a better understanding of the conditions leading to catastrophic debris flow events.

  2. Evolutionary History of a Desert Shrub Ephedra przewalskii (Ephedraceae): Allopatric Divergence and Range Shifts in Northwestern China.

    PubMed

    Su, Zhi-Hao; Zhang, Ming-Li

    2016-01-01

    Based on two chloroplast DNA sequences, psbA-trnH and trnT-trnF, phylogeographical patterns of a desert shrub, Ephedra przewalskii, were examined across most of its geographic range in northwestern China. A total of sixteen haplotypes were detected. There was a common haplotype in each basin, that was haplotype A in Tarim Basin, haplotype G in Junggar Basin, and haplotype M in Qaidam Basin. Genetic variance mainly occurred among populations, geographic regions, and eleven geographic groups subdivided by SAMOVA analysis. E. przewalskii likely had a smaller and more fragmented geographic range during the Last Glacial Maximum, which was determined based on ecological niche modelling. Three groups of E. przewalskii populations were detected to have experience range expansion, and this was based on significant values of Fu's FS, Tajima's D, and unimodel mismatch distributions. The cold and dry climate during the glacial period of the Quaternary is postulated to have been a driver for significant genetic isolation and divergence among populations or groups in E. przewalskii, whereas the warmer and wetter climate during the interglacial period is speculated to have provided favourable conditions for range expansion of the species. PMID:27351630

  3. Modeling nitrate leaching and optimizing water and nitrogen management under irrigated maize in desert oases in Northwestern China.

    PubMed

    Hu, Kelin; Li, Yong; Chen, Weiping; Chen, Deli; Wei, Yongping; Edis, Robert; Li, Baoguo; Huang, Yuanfang; Zhang, Yuanpei

    2010-01-01

    Understanding water and N transport through the soil profile is important for efficient irrigation and nutrient management to minimize nitrate leaching to the groundwater, and to promote agricultural sustainable development in desert oases. In this study, a process-based water and nitrogen management model (WNMM) was used to simulate soil water movement, nitrate transport, and crop growth (maize [Zea mays L.]) under desert oasis conditions in northwestern China. The model was calibrated and validated with a field experiment. The model simulation results showed that about 35% of total water input and 58% of the total N input were leached to <1.8 m depth under traditional management practice. Excessive irrigation and N fertilizer application, high nitrate concentration in the irrigation water, together with the sandy soil texture, resulted in large nitrate leaching. Nitrate leaching was significantly reduced under the improved management practice suggested by farm extension personnel; however, the water and nitrate inputs still far exceeded the crop requirements. More than 1700 scenarios combining various types of irrigation and fertilizer practices were simulated. Quantitative analysis was conducted to obtain the best management practices (BMPs) with simultaneous consideration of crop yield, water use efficiency, fertilizer N use efficiency, and nitrate leaching. The results indicated that the BMPs under the specific desert oasis conditions are to irrigate the maize with 600 mm of water in eight times with a single fertilizer application at a rate of 75 kg N ha(-1).

  4. Modeling nitrate leaching and optimizing water and nitrogen management under irrigated maize in desert oases in Northwestern China.

    PubMed

    Hu, Kelin; Li, Yong; Chen, Weiping; Chen, Deli; Wei, Yongping; Edis, Robert; Li, Baoguo; Huang, Yuanfang; Zhang, Yuanpei

    2010-01-01

    Understanding water and N transport through the soil profile is important for efficient irrigation and nutrient management to minimize nitrate leaching to the groundwater, and to promote agricultural sustainable development in desert oases. In this study, a process-based water and nitrogen management model (WNMM) was used to simulate soil water movement, nitrate transport, and crop growth (maize [Zea mays L.]) under desert oasis conditions in northwestern China. The model was calibrated and validated with a field experiment. The model simulation results showed that about 35% of total water input and 58% of the total N input were leached to <1.8 m depth under traditional management practice. Excessive irrigation and N fertilizer application, high nitrate concentration in the irrigation water, together with the sandy soil texture, resulted in large nitrate leaching. Nitrate leaching was significantly reduced under the improved management practice suggested by farm extension personnel; however, the water and nitrate inputs still far exceeded the crop requirements. More than 1700 scenarios combining various types of irrigation and fertilizer practices were simulated. Quantitative analysis was conducted to obtain the best management practices (BMPs) with simultaneous consideration of crop yield, water use efficiency, fertilizer N use efficiency, and nitrate leaching. The results indicated that the BMPs under the specific desert oasis conditions are to irrigate the maize with 600 mm of water in eight times with a single fertilizer application at a rate of 75 kg N ha(-1). PMID:20176839

  5. Historical Earthquake Records and their Application for Seismic Hazard and Risk Assessment in Tianshui, Gansu Province, Northwestern China

    NASA Astrophysics Data System (ADS)

    Wang, L.; Wang, Z.

    2009-12-01

    Tianshui, located in southeastern Gansu Province of northwestern China, was a center of early Chinese civilization and the birthplace of “Ba Gua” or “eight symbols.” It has a long history of earthquakes and many strong and large earthquakes have occurred there. Earthquakes, ancient or modern ones, have not only been well recorded, but also left marks on many historical landmarks and buildings that can still be seen today. For example, major damage by the 1654 Tianshui earthquake (M8.0) and some minor damage by the 2008 Wenchuan earthquake can be seen in the Maiji Grotto. A new effort to investigate and reexamine the historical macroseismic records is under way, with the aim of better seismic hazard and risk assessment for the Tianshui area. Seismic hazard and risk will be assessed for the Tianshui area using the 2,500 years of intensity observations (records). The results will be used by local governments and communities for developing more effective mitigation policies in the aftermath of the 2008 Wenchuan earthquake. The results will also be compared to hazard and risk assessments derived from other approaches, such as probabilistic and deterministic seismic hazard analyses.

  6. Dietary shift after 3600 cal yr BP and its influencing factors in northwestern China: Evidence from stable isotopes

    NASA Astrophysics Data System (ADS)

    Ma, Minmin; Dong, Guanghui; Jia, Xin; Wang, Hui; Cui, Yifu; Chen, Fahu

    2016-08-01

    Human diets rely on natural resource availability and can reflect social and cultural values. When environments, societies, and cultures change, diets may also shift. This study traced the extent of dietary change and the factors influencing such change. Through stable carbon and nitrogen isotopic analysis of late Neolithic and early Bronze Age human and animal bone collagen, we found that significant shifts in human diets were closely associated with intercontinental cultural exchanges in Eurasia and climate change in northwestern China. The isotopic evidence indicated that human diets mainly consisted of C4 foodstuffs (presumably millet and/or animals fed with C4 foods) around 4000 calibrated years before the present (cal yr BP), corresponding to the flourishing of millet agriculture in the context of the optimal climate conditions of the mid-Holocene. Subsequently, more C3 foods (probably wheat, barley, and animals fed with C3 foods) were added to human diets post-3600 cal yr BP when the climate became cooler and drier. Such dietary variation is also consistent with the increasing intensity of long-distance exchange after 4000 cal yr BP. While many factors can lead to human dietary shifts (e.g. climate change, population growth, cultural factors, and human migration), climate may have been a key factor in Gansu and Qinghai.

  7. Evolutionary History of a Desert Shrub Ephedra przewalskii (Ephedraceae): Allopatric Divergence and Range Shifts in Northwestern China.

    PubMed

    Su, Zhi-Hao; Zhang, Ming-Li

    2016-01-01

    Based on two chloroplast DNA sequences, psbA-trnH and trnT-trnF, phylogeographical patterns of a desert shrub, Ephedra przewalskii, were examined across most of its geographic range in northwestern China. A total of sixteen haplotypes were detected. There was a common haplotype in each basin, that was haplotype A in Tarim Basin, haplotype G in Junggar Basin, and haplotype M in Qaidam Basin. Genetic variance mainly occurred among populations, geographic regions, and eleven geographic groups subdivided by SAMOVA analysis. E. przewalskii likely had a smaller and more fragmented geographic range during the Last Glacial Maximum, which was determined based on ecological niche modelling. Three groups of E. przewalskii populations were detected to have experience range expansion, and this was based on significant values of Fu's FS, Tajima's D, and unimodel mismatch distributions. The cold and dry climate during the glacial period of the Quaternary is postulated to have been a driver for significant genetic isolation and divergence among populations or groups in E. przewalskii, whereas the warmer and wetter climate during the interglacial period is speculated to have provided favourable conditions for range expansion of the species.

  8. Agricultural water supply/demand changes under projected future climate change in the arid region of northwestern China

    NASA Astrophysics Data System (ADS)

    Guo, Ying; Shen, Yanjun

    2016-09-01

    The water resources in the arid region of northwestern China, which are impacted by climate change, tend to be more unstable, and the environment and ecosystems will suffer from severe water shortage. In this paper, potential future climate trends were predicted based on CMIP5 simulations in this region. The water availability and agricultural water demand under future climate change scenarios were estimated. Impacted by increases in temperature, the irrigation water demand will increase by 4.27-6.15 billion m3 in this region over the next 60 years, compared to the demand of 32.75 billion m3 during 1971-2000. However, the annual runoff will only increase by 4.8-8.5 billion m3, which is equivalent to or even less than the increased irrigation water demand. In fact, the increased demand for industrial, domestic and ecological water were not considered here. Thus, the water supply/demand contradiction will result in more severe water shortages in the future. According to a comparison with simulated irrigation water demand under three adaptation strategy scenarios, we should take effective measures such as improving the efficiency of irrigation water utilization, reducing crop planting areas and adjusting crop planting structures to alleviate the impacts of future climate changes and human activities on the water supply and water use in this region.

  9. The distribution characteristics of rare metal elements in surface sediments from four coastal bays on the northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Wang, Shuhong; Li, Jin; Wu, Shuzhuang; Yan, Wen; Huang, Weixia; Miao, Li; Chen, Zhong

    2016-02-01

    The distribution of rare metal elements (Zr, Sn, Ti, Y, Nb, Ta, Ce, La, Nd and Th) in surface sediments from four bays along the northwestern coast of the South China Sea allowed infer their main controlling factors and their mineralization potential as metals placer. The results revealed that their contents in surface sediments are very variable but show a clear geographic regularity. The average content of all elements in those areas decreases from the East to the West, with the minimum value of all elements in Leizhou Bay, the maximum value of Zr, Y, La, Ce, Nd and Th in Zhanjiang Bay, and the maximum values of Sn, Ti, Nb and Ta in Hailing Bay. The relative enrichment of these elements in two easternmost bays (Hailing Bay and Shuidong Bay) are attributed to the southwest alongshore current, which drain and transport terrigenous sediments from the granite region of the South China into these two bays. The correlation results between all element contents and fine sediment fraction (<63 μm) suggested that the main factors controlling the distribution of Ti, Nb and Sn should be the fine fraction of the sediment, but alternatively Zr, Y, La, Ce, Nd and Th are rich in heavy minerals and/or bioclasts, and Ta maybe affected by both. Detail analysis shows that sediments from Hailing Bay may contain abundant zircon, cassiterite, ilmenite (or rutile), xenotime, monazite, niobium tantalite and other rare metal minerals, with a good prospect as a rare metal placer resource, and the zircon, xenotime and monazite may also have good metallogenic prospects in Shuidong Bay and in the local area of Zhangjian Bay.

  10. Contrasting Triassic ferroan granitoids from northwestern Liaoning, North China: Magmatic monitor of Mesozoic decratonization and a craton-orogen boundary

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohui; Yuan, Lingling; Xue, Fuhong; Zhang, Yanbin

    2012-07-01

    The diversity exhibited by ferroan granitoids testifies to multiple distinct crustal and mantle processes generally within extensional environments and thus holds the key to monitoring important geodynamic and crustal evolutionary processes and calibrating terrane tectonic affinity. This study documents three Middle to Late Triassic ferroan granitoid suites from northwestern Liaoning, North China, and proposes distinct petrogenetic scenarios for each. The Middle Triassic (ca. 238 Ma) Ping'andi (PAD) granites are mainly calc-alkali and peraluminous. Their radiogenic whole-rock Nd and zircon Hf isotopic signatures argue for an origin consistent with partial melting of a juvenile quartzofeldspathic crust formed by prior mantle-derived magmatic underplating and their differentiations. By contrast, the Late Triassic (ca. 220 Ma) Dashaoleng (DSL) and Sijiazi (SJZ) suites show an evolved character from alkali-calcic to alkali and from metaluminous to peraluminous. Their variably evolved whole-rock Sr-Nd and mixed zircon Hf isotopic compositions suggest that both suites were formed by variable mixing between depleted mantle-derived mafic magma and old crust-derived felsic magma, with distinctively higher input from juvenile components in the DSL suite. These contrasting ferroan granitoid suites not only provide a spatial marker for monitoring juxtaposition of the North China Craton (NCC) and the Central Asian Orogenic Belt (CAOB) along a lithospheric-scale boundary fault in the region, but also present a temporal snapshot that records a southwardly-progressing crustal growth scenario possibly in response to lithospheric dripping within a post-orogenic extensional regime. The cratonic scale synthesis further indicates that diachronous decratonization pattern of the NCC might record episodic response of the craton to evolved plate tectonic processes with two contrasting Phanerozoic orogenic systems.

  11. The timing of Jurassic orogenesis in the continental arc terrane of the western US Cordillera: Jackston Mountains, northwestern Nevada

    SciTech Connect

    Quinn, M.J.; Wright, J.E. . Dept. of Geology and Geophysics)

    1993-04-01

    Pre-Nevadan, Jurassic orogenesis appears to be characteristic of many Mesozoic arc assemblages of the western US Cordillera. In most places this deformation is Middle Jurassic ([approximately]170--160 Ma). The authors recent work in the Black Rock Desert (BRD) documents an episode of Early Jurassic metamorphism and tectonism in the Jackson Mountains (JM). Here, an extensive arc section, including the Norian to Middle ( ) Jurassic Happy Creek Volcanics and Early to Middle Jurassic plutons, indicate vigorous arc magmatism in the arly Mesozoic. Among the southwest flank of the range the lower Mesozoic section is overridden by an east vergent thrust sheet carrying upper Paleozoic rocks of the McGill Canyon Unit. Another thrust package is located on the same side of the range, but further to the north, and contains variably metamorphosed clastic rocks, carbonate, and mafic volcanics. There is also an abrupt drop in metamorphic grade across the main thrust fault where greenschist facies rocks are in contact with virtually unmetamorphosed Happy Creek Volcanics. Two plutons with U/Pb zircon age of 188 [+-] 2 Ma and 193 [+-] 3 Ma crosscut the northern thrust fault. These relations suggest than an episode of regional metamorphism followed by E-W compressional tectonism was completed during the Early Jurassic in this portion of the arc terrane. These results differ significantly from previous studies that have interpreted all compressive deformation in the JM to have taken place between the Middle Jurassic and Cretaceous. The authors new data indicate that pre-Nevada Jurassic deformation is somewhat older in the BRD than that documented in other parts of the Mesozoic arc. Because voluminous Jurassic magmatism also began at an earlier time (Early Jurassic) in the BRD than elsewhere, they suggest that deformation and metamorphis within the arc may be facilitated and localized during periods of high heat flux related to magmatic input.

  12. The first documented report of mountain sickness: the China or Headache Mountain story.

    PubMed

    Gilbert, D L

    1983-06-01

    This article gives the probable location within 65 km of the Big Headache Mountain where mountain sickness was first reported by Too Kin, a Chinese official, in 37-32 B.C. We believe that traveling over the western edge of the Himalayan Karakoram Range or in the Pamirs caused the major difficulties, probably when travelers crossed the Kilik Pass at an altitude of 4827 m or 15837 ft or within 60 km of this pass and at an altitude of at least 4500 m or 14750 ft. We theorize that the route Too Kin described is from Kashi, an important center in Sinkiang or Chinese Turkestan, to Kabul in Afghanistan. This particular route has two other altitude maxima; one at the Ulagh Rabat Pass in Sinkiang about 15 km west of the Muztagata peak where the elevation is 4250 m or 14000 ft, and the other at the Shandur Pass over the Hindu Kush in Pakistan where the elevation is 3734 m or 12250 ft. PMID:6351209

  13. Precipitation chemistry and corresponding transport patterns of influencing air masses at Huangshan Mountain in East China

    NASA Astrophysics Data System (ADS)

    Shi, ChunE; Deng, Xueliang; Yang, Yuanjian; Huang, Xiangrong; Wu, Biwen

    2014-09-01

    One hundred and ten samples of rainwater were collected for chemical analysis at the summit of Huangshan Mountain, a high-altitude site in East China, from July 2010 to June 2011. The volume-weighted-mean (VWM) pH for the whole sampling period was 5.03. SO{4/2-} and Ca2+ were the most abundant anion and cation, respectively. The ionic concentrations varied monthly with the highest concentrations in winter/spring and the lowest in summer. Evident inter-correlations were found among most ions, indicating the common sources for some species and fully mixing characteristics of the alpine precipitation chemistry. The VWM ratio of [SO{4/2-}]/[NO{3/-}] was 2.54, suggesting the acidity of rainwater comes from both nitric and sulfuric acids. Compared with contemporary observations at other alpine continental sites in China, the precipitation at Huangshan Mountain was the least polluted, with the lowest ionic concentrations. Trajectories to Huangshan Mountain on rainy days could be classified into six groups. The rainwater with influencing air masses originating in Mongolia was the most polluted with limited effect. The emissions of Jiangxi, Anhui, Zhejiang and Jiangsu provinces had a strong influence on the overall rain chemistry at Huangshan Mountain. The rainwater with influencing air masses from Inner Mongolia was heavily polluted by anthropogenic pollutants.

  14. Papiliocoelotes gen. n., a new genus of Coelotinae (Araneae, Agelenidae) spiders from the Wuling Mountains, China

    PubMed Central

    Zhao, Zhe; Li, Shuqiang

    2016-01-01

    Abstract One new genus of the spider subfamily Coelotinae, Papiliocoelotes gen. n., with five new species is described for both sexes: Papiliocoelotes guanyinensis sp. n., Papiliocoelotes guitangensis sp. n., Papiliocoelotes jiepingensis sp. n., Papiliocoelotes meiyuensis sp. n., Papiliocoelotes yezhouensis sp. n. All new species were collected from caves in the Wuling Mountains of Hubei and Hunan Provinces, China. DNA barcodes were obtained for future use. PMID:27199603

  15. Papiliocoelotes gen. n., a new genus of Coelotinae (Araneae, Agelenidae) spiders from the Wuling Mountains, China.

    PubMed

    Zhao, Zhe; Li, Shuqiang

    2016-01-01

    One new genus of the spider subfamily Coelotinae, Papiliocoelotes gen. n., with five new species is described for both sexes: Papiliocoelotes guanyinensis sp. n., Papiliocoelotes guitangensis sp. n., Papiliocoelotes jiepingensis sp. n., Papiliocoelotes meiyuensis sp. n., Papiliocoelotes yezhouensis sp. n. All new species were collected from caves in the Wuling Mountains of Hubei and Hunan Provinces, China. DNA barcodes were obtained for future use. PMID:27199603

  16. Origins of groundwater inferred from isotopic patterns of the Badain Jaran Desert, northwestern China.

    PubMed

    Zhao, Liangju; Xiao, Honglang; Dong, Zhibao; Xiao, Shengchun; Zhou, Maoxian; Cheng, Guodong; Yin, Li; Yin, Zhenliang

    2012-01-01

    There are many viewpoints about the sources of groundwater in the Badain Jaran Desert (BJD), such as precipitation and snowmelt from the Qilian Mountains (the upper reaches [UR] of the Heihe River Basin [HRB]) and precipitation from the BJD and the Yabulai Mountains. To understand the source of the groundwater of the BJD and their possible associations with nearby bodies of water, we analyzed variations of stable isotope ratios (δD and δ(18) O) and the deuterium excess (d-excess) of groundwater and precipitation in the BJD, of groundwater, precipitation, river and spring water in the UR, and of groundwater and river water in the middle and lower reaches (MR and LR) of the HRB. In addition, the climatic condition under which the groundwater was formed in the BJD was also discussed. We found obvious differences in δD, δ(18) O, and d-excess among groundwater in the BJD, nearby water bodies and the HRB. The groundwater δD-δ(18) O equation for the BJD was δD = 4.509δ(18) O-30.620, with a slope and intercept similar to that of nearby areas (4.856 and -29.574), indicating a strong evaporation effect in the BJD and its surrounding areas. The equation's slope of the BJD was significantly lower than those of HRB groundwater (6.634), HRB river water (6.202), precipitation in the BJD and Youqi (7.841), and the UR of the HRB (7.839). The d-excess (-17.5‰) of the BJD was significantly lower than those of nearby groundwater (-7.4‰), HRB groundwater (12.1‰), precipitation in the BJD (5.7‰) and in the UR of the HRB (15.2‰), and HRB river water (14.4‰). The spatial patterns of δ(18) O and d-excess values in the BJD suggest mixing and exchange of groundwater between the BJD and neighboring regions, but no hydraulic relationship between the BJD groundwater and water from more distant regions except Outer Mongolia, which is north of the BJD. Moreover, we conclude that there is little precipitation recharge to groundwater because of the obvious d-excess difference

  17. Origins of groundwater inferred from isotopic patterns of the Badain Jaran Desert, northwestern China.

    PubMed

    Zhao, Liangju; Xiao, Honglang; Dong, Zhibao; Xiao, Shengchun; Zhou, Maoxian; Cheng, Guodong; Yin, Li; Yin, Zhenliang

    2012-01-01

    There are many viewpoints about the sources of groundwater in the Badain Jaran Desert (BJD), such as precipitation and snowmelt from the Qilian Mountains (the upper reaches [UR] of the Heihe River Basin [HRB]) and precipitation from the BJD and the Yabulai Mountains. To understand the source of the groundwater of the BJD and their possible associations with nearby bodies of water, we analyzed variations of stable isotope ratios (δD and δ(18) O) and the deuterium excess (d-excess) of groundwater and precipitation in the BJD, of groundwater, precipitation, river and spring water in the UR, and of groundwater and river water in the middle and lower reaches (MR and LR) of the HRB. In addition, the climatic condition under which the groundwater was formed in the BJD was also discussed. We found obvious differences in δD, δ(18) O, and d-excess among groundwater in the BJD, nearby water bodies and the HRB. The groundwater δD-δ(18) O equation for the BJD was δD = 4.509δ(18) O-30.620, with a slope and intercept similar to that of nearby areas (4.856 and -29.574), indicating a strong evaporation effect in the BJD and its surrounding areas. The equation's slope of the BJD was significantly lower than those of HRB groundwater (6.634), HRB river water (6.202), precipitation in the BJD and Youqi (7.841), and the UR of the HRB (7.839). The d-excess (-17.5‰) of the BJD was significantly lower than those of nearby groundwater (-7.4‰), HRB groundwater (12.1‰), precipitation in the BJD (5.7‰) and in the UR of the HRB (15.2‰), and HRB river water (14.4‰). The spatial patterns of δ(18) O and d-excess values in the BJD suggest mixing and exchange of groundwater between the BJD and neighboring regions, but no hydraulic relationship between the BJD groundwater and water from more distant regions except Outer Mongolia, which is north of the BJD. Moreover, we conclude that there is little precipitation recharge to groundwater because of the obvious d-excess difference

  18. Crop evapotranspiration-based irrigation management during the growing season in the arid region of northwestern China.

    PubMed

    Chang, Xuexiang; Zhao, Wenzhi; Zeng, Fanjiang

    2015-11-01

    In arid northwestern China, water shortages have triggered recent regulations affecting irrigation water use in desert-oasis agricultural systems. In order to determine the actual water demand of various crops and to develop standards for the rational use of water resources, we analyzed meteorological data from the Fukang desert ecosystem observation and experiment station (FKD), the Cele desert-grassland ecosystem observation and research station (CLD), and the Linze Inland River Basin Comprehensive Research Station (LZD), which all belong to the Chinese Ecosystem Research Network. We researched crop evapotranspiration (ETc) using the water balance method, the FAO-56 Penman-Monteith method, the Priestley-Taylor method, and the Hargreaves method, during the growing seasons of 2005 through 2009. Results indicate substantial differences in ETc, depending on the method used. At the CLD, the ETc from the soil water balance, FAO-56 Penman-Monteith, Priestley-Taylor, and Hargreaves methods were 1150.3±380.8, 783.7±33.6, 1018.3±22.1, and 611.2±23.3 mm, respectively; at the FKD, the corresponding results were 861.0±67.0, 834.2±83.9, 1453.5±47.1, and 1061.0±38.2 mm, respectively; and at the LZD, 823.4±110.4, 726.0±0.4, 722.3±29.4, and 1208.6±79.1 mm, respectively. The FAO-56 Penman-Monteith method provided a fairly good estimation of E Tc compared with the Priestley-Taylor and Hargreaves methods. PMID:26497559

  19. A 368-year maximum temperature reconstruction based on tree-ring data in the northwestern Sichuan Plateau (NWSP), China

    NASA Astrophysics Data System (ADS)

    Zhu, Liangjun; Zhang, Yuandong; Li, Zongshan; Guo, Binde; Wang, Xiaochun

    2016-07-01

    We present a reconstruction of July-August mean maximum temperature variability based on a chronology of tree-ring widths over the period AD 1646-2013 in the northern part of the northwestern Sichuan Plateau (NWSP), China. A regression model explains 37.1 % of the variance of July-August mean maximum temperature during the calibration period from 1954 to 2012. Compared with nearby temperature reconstructions and gridded land surface temperature data, our temperature reconstruction had high spatial representativeness. Seven major cold periods were identified (1708-1711, 1765-1769, 1818-1821, 1824-1828, 1832-1836, 1839-1842, and 1869-1877), and three major warm periods occurred in 1655-1668, 1719-1730, and 1858-1859 from this reconstruction. The typical Little Ice Age climate can also be well represented in our reconstruction and clearly ended with climatic amelioration at the late of the 19th century. The 17th and 19th centuries were cold with more extreme cold years, while the 18th and 20th centuries were warm with less extreme cold years. Moreover, the 20th century rapid warming was not obvious in the NWSP mean maximum temperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change as unique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significant periodicities of 170-, 49-114-, 25-32-, 5.7-, 4.6-4.7-, 3.0-3.1-, 2.5-, and 2.1-2.3-year quasi-cycles at a 95 % confidence level in our reconstruction. Overall, the mean maximum temperature variability in the NWSP may be associated with global land-sea atmospheric circulation (e.g., ENSO, PDO, or AMO) as well as solar and volcanic forcing.

  20. Crop evapotranspiration-based irrigation management during the growing season in the arid region of northwestern China.

    PubMed

    Chang, Xuexiang; Zhao, Wenzhi; Zeng, Fanjiang

    2015-11-01

    In arid northwestern China, water shortages have triggered recent regulations affecting irrigation water use in desert-oasis agricultural systems. In order to determine the actual water demand of various crops and to develop standards for the rational use of water resources, we analyzed meteorological data from the Fukang desert ecosystem observation and experiment station (FKD), the Cele desert-grassland ecosystem observation and research station (CLD), and the Linze Inland River Basin Comprehensive Research Station (LZD), which all belong to the Chinese Ecosystem Research Network. We researched crop evapotranspiration (ETc) using the water balance method, the FAO-56 Penman-Monteith method, the Priestley-Taylor method, and the Hargreaves method, during the growing seasons of 2005 through 2009. Results indicate substantial differences in ETc, depending on the method used. At the CLD, the ETc from the soil water balance, FAO-56 Penman-Monteith, Priestley-Taylor, and Hargreaves methods were 1150.3±380.8, 783.7±33.6, 1018.3±22.1, and 611.2±23.3 mm, respectively; at the FKD, the corresponding results were 861.0±67.0, 834.2±83.9, 1453.5±47.1, and 1061.0±38.2 mm, respectively; and at the LZD, 823.4±110.4, 726.0±0.4, 722.3±29.4, and 1208.6±79.1 mm, respectively. The FAO-56 Penman-Monteith method provided a fairly good estimation of E Tc compared with the Priestley-Taylor and Hargreaves methods.

  1. Comparing Soil Organic Carbon Dynamics in Perennial Grasses and Shrubs in a Saline-Alkaline Arid Region, Northwestern China

    PubMed Central

    Su, Jiaqi; Zhang, Jingli; Zheng, Yuanrun; Ni, Jian; Xiao, Chunwang; Wang, Renzhong

    2012-01-01

    Background Although semi-arid and arid regions account for about 40% of terrestrial surface of the Earth and contain approximately 10% of the global soil organic carbon stock, our understanding of soil organic carbon dynamics in these regions is limited. Methodology/Principal Findings A field experiment was conducted to compare soil organic carbon dynamics between a perennial grass community dominated by Cleistogenes squarrosa and an adjacent shrub community co-dominated by Reaumuria soongorica and Haloxylon ammodendron, two typical plant life forms in arid ecosystems of saline-alkaline arid regions in northwestern China during the growing season 2010. We found that both fine root biomass and necromass in two life forms varied greatly during the growing season. Annual fine root production in the perennial grasses was 45.6% significantly higher than in the shrubs, and fine root turnover rates were 2.52 and 2.17 yr−1 for the perennial grasses and the shrubs, respectively. Floor mass was significantly higher in the perennial grasses than in the shrubs due to the decomposition rate of leaf litter in the perennial grasses was 61.8% lower than in the shrubs even though no significance was detected in litterfall production. Soil microbial biomass and activity demonstrated a strong seasonal variation with larger values in May and September and minimum values in the dry month of July. Observed higher soil organic carbon stocks in the perennial grasses (1.32 Kg C m−2) than in the shrubs (1.12 Kg C m−2) might be attributed to both greater inputs of poor quality litter that is relatively resistant to decay and the lower ability of microorganism to decompose these organic matter. Conclusions/Significance Our results suggest that the perennial grasses might accumulate more soil organic carbon with time than the shrubs because of larger amounts of inputs from litter and slower return of carbon through decomposition. PMID:22900067

  2. Mesozoic hydrocarbon source rock studies of north Tarim, south Junggar, and Turpan basins, Xinjiang Uygur autonomous region, northwestern China

    SciTech Connect

    Hendrix, M.S.; Xiao, Z.; Liang, Y.; Graham, S.A.; Carroll, A.R.; Chu, J.; McKnight, C.

    1989-03-01

    Ongoing outcrop and accompanying pyrolysis studies of Mesozoic strata of the north Tarim, south Junggar, and Turpan retroarc foreland basins, northwestern China, have demonstrated the existence of potential oil-prone and gas-prone petroleum source rocks. Lithologies include Jurassic coals from all three basins and Triassic coals from Tarim. Jurassic coals collected from the Mesozoic depocenters of the Junggar and Tarim basins are oil prone, yielding S/sub 2//S/sub 2+3/ values that range from 0.80 to 0.99 and average 0.96, hydrogen index (HI) values that range from 117.9 to 213.4 and average 150.8, and oxygen index (OI) values that range from 1.1 to 31.6 and average 7.67. In contrast, Triassic coals of Tarim and Jurassic coals of Turpan contain more conventional type III gas-prone kerogens and yield S/sub 2//S/sub 2+3/ values ranging from 0.04 to 0.52 and averaging 0.22, HI values ranging from 3.2 to 130.2 with a mean of 33.6, and OI values ranging from 30.9 to 223.7 and averaging 115.9. Coals of all three basins are slightly immature to mature with respect to oil generation, as indicated by T/sub max/ values ranging from 425/degrees/ to 449/degrees/C (average = 343/degrees/C) and vitrinite reflectance values ranging from 0.51 to 0.64 (average = 0.57). Thus, given the widespread abundance and significant thicknesses of Mesozoic and especially Jurassic coals in all three basins, it is very likely that Mesozoic contributions to Xinjiang's oil and gas reserves are significant. This is particularly important in the north Tarim basin, where recent Chinese oil and gas discoveries have been made and the existence of significant pre-Mesozoic source beds remains unproven.

  3. Feasibility of EPS-producing bacterial inoculation to speed up the sand aggregation in the Gurbantunggut Desert, Northwestern China.

    PubMed

    Wu, Nan; Pan, Hui-Xia; Qiu, Dong; Zhang, Yuan-Ming

    2014-12-01

    Exopolymers are known to be useful in improving sand aggregation and the development of biological soil crusts (BSCs). A facultative bacterium KLBB0001 was isolated from BSCs in the Gurbantunggut Desert in northwestern China. With the strong effective production of extracellular polymeric substances (EPS), this strain exhibits a multifunctional role for sand stabilization and maintenance of water under laboratory conditions. Practical testing of the feasibility of its inoculation to speed up BSC recovery in the field was also conducted in this experiment. This strain stimulated the heterotrophic community assembly in the topsoil layer (0-2 cm) before the commencement of autotrophic cyanobacteria, while also significantly increasing the number of bacteria, actinomycetes, and content of total phosphorus, available nitrogen, and available phosphorus. However, the low nitrogenase activity (NA) (0.57 µmol/h) that was observed caused us to doubt the previous identification as Azotobacter Beijerinck that was based on physiological and biochemical properties. A phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain was a member of the genus Paenibacillus. It exhibited the closest phylogenetic affinity and highest sequence similarity to the strain Paenibacillus mucilaginosus VKPM B-7519 (sequence similarity 99.698%), which is well known as a typical silicate-weathering bacteria that releases lots of nutritional ions from minerals and the soil. Because P. mucilaginosus can excrete carbonic anhydrase (CA) to capture atmospheric CO2 through hydration of CO2 , it is possible that KLBB0001 might use a similar strategy for heterotrophs in the BSCs to sequester CO2 from the air. Because of its potential role in the reestablishment of the BSC ecosystem due to its ability to improve water relations, sand stabilization, and chemical erosion, EPS-producing bacterial inoculation was concluded to be a suitable and effective treatment for BSC recovery

  4. Landsat and SPOT data for oil exploration in North-Western China

    SciTech Connect

    Nishidai, Takashi |

    1996-07-01

    Satellite remote sensing technology has been employed by Japex to provide information related to oil exploration programs for many years. Since the beginning of the 1980`s, regional geological interpretation through to advanced studies using satellite imagery with high spectral and spatial resolutions (such as Landsat TM and SPOT HRV), have been carried out, for both exploration programs and for scientific research. Advanced techniques (including analysis of airborne hyper-multispectral imaging sensor data) as well as conventional photogeological techniques were used throughout these programs. The first program using remote sensing technology in China focused on the Tarim Basin, Xinjiang Uygur Autonomous Region, and was carried out using Landsat MSS data. Landsat MSS imagery allows us to gain useful preliminary geological information about an area of interest, prior to field studies. About 90 Landsat scenes cover the entire Xinjiang Uygru Autonomous Region, this allowed us to give comprehensive overviews of 3 hydrocarbon-bearing basins (Tarim, Junggar, and Turpan-Hami) in NW China. The overviews were based on the interpretations and assessments of the satellite imagery and on a synthesis of the most up-to-date accessible geological and geophysical data as well as some field works. Pairs of stereoscopic SPOT HRV images were used to generate digital elevation data with a 40 in grid cover for part of the Tarim Basin. Topographic contour maps, created from this digital elevation data, at scales of 1:250,000 and 1:100,000 with contour intervals of 100 m and 50 m, allowed us to make precise geological interpretation, and to carry out swift and efficient geological field work. Satellite imagery was also utilized to make medium scale to large scale image maps, not only to interpret geological features but also to support field workers and seismic survey field operations.

  5. Spatial variability and stocks of soil organic carbon in the Gobi desert of Northwestern China.

    PubMed

    Zhang, Pingping; Shao, Ming'an

    2014-01-01

    Soil organic carbon (SOC) plays an important role in improving soil properties and the C global cycle. Limited attention, though, has been given to assessing the spatial patterns and stocks of SOC in desert ecosystems. In this study, we quantitatively evaluated the spatial variability of SOC and its influencing factors and estimated SOC storage in a region (40 km2) of the Gobi desert. SOC exhibited a log-normal depth distribution with means of 1.6, 1.5, 1.4, and 1.4 g kg(-1) for the 0-10, 10-20, 20-30, and 30-40 cm layers, respectively, and was moderately variable according to the coefficients of variation (37-42%). Variability of SOC increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. Significant correlations were detected between SOC and soil physical properties, i.e. stone, sand, silt, and clay contents and soil bulk density. The relatively coarse fractions, i.e. sand, silt, and stone contents, had the largest effects on SOC variability. Experimental semivariograms of SOC were best fitted by exponential models. Nugget-to-sill ratios indicated a strong spatial dependence for SOC concentrations at all depths in the study area. The surface layer (0-10 cm) had the largest spatial dependency compared with the other layers. The mapping revealed a decreasing trend of SOC concentrations from south to north across this region of the Gobi desert, with higher levels close to an oasis and lower levels surrounded by mountains and near the desert. SOC density to depths of 20 and 40 cm for this 40 km2 area was estimated at 0.42 and 0.68 kg C m(-2), respectively. This study provides an important contribution to understanding the role of the Gobi desert in the global carbon cycle. PMID:24733073

  6. Spatial variability and stocks of soil organic carbon in the Gobi desert of Northwestern China.

    PubMed

    Zhang, Pingping; Shao, Ming'an

    2014-01-01

    Soil organic carbon (SOC) plays an important role in improving soil properties and the C global cycle. Limited attention, though, has been given to assessing the spatial patterns and stocks of SOC in desert ecosystems. In this study, we quantitatively evaluated the spatial variability of SOC and its influencing factors and estimated SOC storage in a region (40 km2) of the Gobi desert. SOC exhibited a log-normal depth distribution with means of 1.6, 1.5, 1.4, and 1.4 g kg(-1) for the 0-10, 10-20, 20-30, and 30-40 cm layers, respectively, and was moderately variable according to the coefficients of variation (37-42%). Variability of SOC increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. Significant correlations were detected between SOC and soil physical properties, i.e. stone, sand, silt, and clay contents and soil bulk density. The relatively coarse fractions, i.e. sand, silt, and stone contents, had the largest effects on SOC variability. Experimental semivariograms of SOC were best fitted by exponential models. Nugget-to-sill ratios indicated a strong spatial dependence for SOC concentrations at all depths in the study area. The surface layer (0-10 cm) had the largest spatial dependency compared with the other layers. The mapping revealed a decreasing trend of SOC concentrations from south to north across this region of the Gobi desert, with higher levels close to an oasis and lower levels surrounded by mountains and near the desert. SOC density to depths of 20 and 40 cm for this 40 km2 area was estimated at 0.42 and 0.68 kg C m(-2), respectively. This study provides an important contribution to understanding the role of the Gobi desert in the global carbon cycle.

  7. Spatial Variability and Stocks of Soil Organic Carbon in the Gobi Desert of Northwestern China

    PubMed Central

    Zhang, Pingping; Shao, Ming'an

    2014-01-01

    Soil organic carbon (SOC) plays an important role in improving soil properties and the C global cycle. Limited attention, though, has been given to assessing the spatial patterns and stocks of SOC in desert ecosystems. In this study, we quantitatively evaluated the spatial variability of SOC and its influencing factors and estimated SOC storage in a region (40 km2) of the Gobi desert. SOC exhibited a log-normal depth distribution with means of 1.6, 1.5, 1.4, and 1.4 g kg−1 for the 0–10, 10–20, 20–30, and 30–40 cm layers, respectively, and was moderately variable according to the coefficients of variation (37–42%). Variability of SOC increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. Significant correlations were detected between SOC and soil physical properties, i.e. stone, sand, silt, and clay contents and soil bulk density. The relatively coarse fractions, i.e. sand, silt, and stone contents, had the largest effects on SOC variability. Experimental semivariograms of SOC were best fitted by exponential models. Nugget-to-sill ratios indicated a strong spatial dependence for SOC concentrations at all depths in the study area. The surface layer (0–10 cm) had the largest spatial dependency compared with the other layers. The mapping revealed a decreasing trend of SOC concentrations from south to north across this region of the Gobi desert, with higher levels close to an oasis and lower levels surrounded by mountains and near the desert. SOC density to depths of 20 and 40 cm for this 40 km2 area was estimated at 0.42 and 0.68 kg C m−2, respectively. This study provides an important contribution to understanding the role of the Gobi desert in the global carbon cycle. PMID:24733073

  8. Development stages of hazardous mountain lakes and simulation of their outbursts (Central Caucasus, Russia; Sichuan mountain region, China).

    NASA Astrophysics Data System (ADS)

    Kidyaeva, Vera; Krylenko, Inna; Chernomorets, Sergey; Petrakov, Dmitry

    2013-04-01

    The importance of mountain lakes studies is related to the increasing threat of natural disasters, associated with lake outbursts and debris flows formation, because of population growth on exposed areas. The outburst hazard has not been sufficiently researched, there is a lack of data because of the lakes inaccessibility and remote sensing data is usually not detailed enough. The main scientific topics include assessment of outburst possibility and further simulation of possible outbursts scenarios. There are two types of mountain lakes: glacial (cirque, cirque-moraine, barrier-moraine, glacial-barrier, etc.) lakes and barrier (landslide, rockfall, debris flow, etc.) lakes. The first type was studied in the Central Caucasus (Russia), and the second type - in the Sichuan mountain region (China). The group of scientists, including authors, has been monitoring glacial lakes in the Mnt. Elbrus area for more than ten years. The unique data were collected, including detailed hydrological characteristics of more than ten lakes (water level dynamics, temperature, morphometrical characteristics, water balance components, etc.). Outbursts of at least three glacial lakes were observed. Hydrological characteristics of landslide Tangjiashan Lake were collected with Chinese colleagues during field studies in 2010 and 2011 years. Analysis of the collected data was used to understand the outburst mechanisms, formation factors, dam breaking factors, development stages of mountain lakes. Statistical methods of analysis in this case can be applied with some limitations because of the lack of sufficient monitoring objects, and therefore the results has been verified by experts. All types of possible outbursts mechanisms were divided by the authors into five groups: geomorphologic (caused by changes in lake dams), seismic, or geodynamic (caused by seiches, waves from rockfalls, landslides), glacial (caused by breaks in impounding glaciers, ice floating and melting), water

  9. A toxicological study of inhalable particulates in an industrial region of Lanzhou City, northwestern China: Results from plasmid scission assay

    NASA Astrophysics Data System (ADS)

    Xiao, Zhenghui; Shao, Longyi; Zhang, Ning; Wang, Jing; Chuang, Hsiao-Chi; Deng, Zhenzhen; Wang, Zhen; BéruBé, Kelly

    2014-09-01

    The city of Lanzhou in northwestern China experiences serious air pollution episodes in the form of PM10 that is characterized by having high levels of heavy metals. The Xigu District represents the industrial core area of Lanzhou City and is denoted by having the largest petrochemical bases in western China. This study investigates heavy metal compositions and oxidative potential of airborne PM10 (particulate matter with aerodynamic diameter of 10 μm or less) collected in Xigu District in the summer and winter of 2010. An in vitro plasmid scission assay (PSA) was employed to study the oxidative potential of airborne PM10 and inductively coupled plasma-mass spectrometry (ICP-MS) was used to examine heavy metal compositions. Transmission electron microscopy coupled with energy-dispersive X-ray spectrometry (TEM/EDX) was used to investigate elemental compositions and mixing states of PM10. The average mass concentrations of PM10 collected in Xigu District were generally higher than the national standard for daily PM10 (150 μg/m3). Cr, Zn, Pb and Mn were the most abundant metals in the intact whole particles of PM10. Zn, Mn and As was the most abundant metal in the water-soluble fraction, while Cr, Pb, and V existed primarily in insoluble forms. TD20 values (i.e. toxic dosage of PM10 causing 20% of plasmid DNA damage) varied considerably in both winter and summer (from 19 μg/mL to >1000 μg/mL) but were typically higher in summer, suggesting that the winter PM10 exhibited greater bioreactivity. In addition, the PM10 collected during a dust storm episode had a highest TD20 value and thus the least oxidative damage to supercoiled plasmid DNA, while the particles collected on a hazy day had a lowest TD20 value and thus the highest oxidative damage to supercoiled plasmid DNA. The particles collected on the first day after snow fall and on a day of cold air intrusion exhibited minor oxidative potential (i.e. caused limited DNA damage). The water-soluble Zn, Mn, As, and

  10. Comparative homegarden medical ethnobotany of Naxi healers and farmers in Northwestern Yunnan, China

    PubMed Central

    2014-01-01

    Background Homegardens are ecologically and culturally important systems for cultivating medicinal plants for wellbeing by healers and farmers in Naxi communities of the Sino Himalayan region. The cultivation of medicinal plants in Naxi communities and associated ethnomedical knowledge base for maintaining and utilizing these resources is at risk with expanded commercialization of natural resources, development policies and rapid socio-economic change in China. Research is needed to understand the medicinal plant species maintained in Naxi homegardens, their use and contribution to community wellbeing, and how these practices and knowledge base varies between Naxi healers and farmers in order to develop plans for biodiversity conservation and preservation of ethnomedical practices. The main objective of this study is to document and compare medicinal plant species in Naxi homegardens and associated ethnomedical knowledge between Naxi healers and farmers. Methods Ethnobotanical homegarden surveys were conducted with three Naxi healers and 28 farmer households in two Naxi communities in Lijiang Prefecture in Northwest Yunnan Province of China. Surveys included inventories of medicinal plants in homegardens and semi-structured interviews with homegarden managers to document traditional medicinal uses of inventoried plants. Inventoried plants were classified into 13 ‘usage categories’ of medical condition groupings that impact a system of the body. Finally, plant species richness was calculated for each homegarden and species richness was compared between healers and farmers as well as between study sites using a Least Square Means Tukey HSD function. Results Ethnobotanical surveys at the study sites found that 13% of households rely exclusively on traditional Naxi medicine, 26% exclusively use Western medicine and 61% use a combination of traditional Naxi and Western medicine. A total of 106 medicinal plants were inventoried in Naxi homegardens representing 50

  11. Active anthropogenic and surface salt deformation measured by InSAR, northwestern China

    NASA Astrophysics Data System (ADS)

    Colon, C.; Webb, A. G.; Lasserre, C.; Doin, M. P.

    2014-12-01

    Despite the global occurrence of salt, very few salt bodies outcrop and are presently preserved at the surface. Because of this much of our knowledge on salt structures is sourced from subsurface imaging and modeling and less from field based studies. Using interferometry of synthetic aperture radar (InSAR) we monitor surface displacements across four surface salt outcrops in the western margin of the Kuqa fold-thrust belt of Xinjiang Province, China. An InSAR time series was constructed from 40 Envisat ASAR C-band images between June 2003 and October 2010. Interferometric processing was completed using the New Small Baseline Algorithm Subset (NSBAS). These poorly studied salt structures provide a fresh opportunity to study how salt behaves on the surface. The salt bodies outcrop along an active intracontinental thrust system between the Tian Shan and Tarim basin to the south. The four surface namakiers (salt glaciers) were analyzed in this study include: the Quele, Awate, Bozidun, and an unnamed structure referred to as the Western namakier. The ~35 km long Quele namakier is a line-sourced structure advancing along the Quele salt thrust. The other three namakiers range between ~1-3 km long and are point-sourced structures. The namakiers studied display non-steady deformation with rates of displacement varying between uplifts of up to +4 cm/yr and subsidence rates of -4 cm/yr. Additionally, the Kuqa fold-thrust belt hosts a number of hydrocarbon fields and InSAR measurements detect significant anthropogenic deformation associated with hydrocarbon extraction and fluid injection.

  12. Characterization of Pu concentration and its isotopic composition in soils of Gansu in northwestern China.

    PubMed

    Zheng, Jian; Yamada, Masatoshi; Wu, Fengchang; Liao, Haiqing

    2009-01-01

    The total 239+240Pu activities and 240Pu/239Pu atom ratios in surface soil samples (0-5cm) in the Kumtag Desert in western Gansu Province, and in a soil core sample in Lanzhou were investigated using a sector-field ICP-MS. In the surface soil samples, 239+240Pu activities in fine particles (<150microm) were 1.3-2.1 times of those in coarse particles (150microm-1mm) which ranged from 0.005 to 0.157mBq/g. Atom ratios of 240Pu/239Pu in the surface soils ranged from 0.168 to 0.192 with a mean of 0.182+/-0.008. The mean ratio was similar to the typical global fallout value although the Kumtag Desert was believed to have received close-in fallout derived from Chinese nuclear weapons tests mainly conducted in the 1970s. Furthermore, the mean 240Pu/239Pu atom ratio observed in the soil core sample in Lanzhou was similar to the typical global fallout value. In the soil core sample, 239+240Pu activities in the various layers ranged from 0.012 to 0.23mBq/g, and the inventory of 239+240Pu (32.4Bq/m2, 0-23cm) was slightly lower than that expected from global fallout (42Bq/m2) at the same latitude. Rapid downward migration of Pu isotopes was observed in Lanzhou soil core sample layers. The contribution of the 10-cm deep top layers of surface soils to total inventory was only 17%, while the contribution of deeper layers (10-23cm) was as high as 83%. The 239+240Pu activity levels and 240Pu/239Pu atom ratios in soils in Gansu Province, China are similar to those in atmospheric deposition samples collected in the spring in recent years in Japan.

  13. Relationship between tourism development and vegetated landscapes in Luya Mountain Nature Reserve, Shanxi, China.

    PubMed

    Cheng, Zhan-Hong; Zhang, Jin-Tun

    2005-09-01

    The relationship between tourism development and vegetated landscapes is analyzed for the Luya Mountain Nature Reserve (LMNR), Shanxi, China, in this study. Indices such as Sensitive Level (SL), Landscape Importance Value (LIV), information index of biodiversity (H'), Shade-tolerant Species Proportion (SSP), and Tourism Influencing Index (TII) are used to characterize vegetated landscapes, the impact of tourism, and their relationship. Their relationship is studied by Two-Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA). TWINSPAN gives correct and rapid partition to the classification, and DCA ordination shows the changing tendency of all vegetation types based on tourism development. These results reflect the ecological relationship between tourism development and vegetated landscapes. In Luya Mountain Nature Reserve, most plant communities are in good or medium condition, which shows that these vegetated landscapes can support more tourism. However, the occurrence of the bad condition shows that there is a severe contradiction between tourism development and vegetated landscapes.

  14. Atmospheric mercury deposition recorded in an ombrotrophic peat core from Xiaoxing'an Mountain, Northeast China

    SciTech Connect

    Tang, Shunlin; Huang, Zhongwei; Liu, Jun; Yang, Zaichan; Lin, Qinhua

    2012-10-15

    The historical mercury accumulation rates (Hg AR) resulting from atmospheric deposition to Xiaoxing'an Mountain were determined via analysis of {sup 210}Pb- and {sup 14}C-dated cores up to 5000 years old. Natural Hg AR background, pre-industrial Hg AR and maximum industrial Hg AR in Northeast China were 2.2 {+-}1.0 {mu}g/m{sup 2}/yr for 5100-4500 BP, 5.7 {mu}g/m{sup 2}/yr and 112.4 {mu}g/m{sup 2}/yr, respectively. We assumed that the increase in Hg deposition in the Xiaoxing'an mountain area during industrial time was mainly attributed to local anthropogenic emissions around this peat bog.

  15. Origin of the Early Permian zircons in Keping basalts and magma evolution of the Tarim Large Igneous Province (northwestern China)

    NASA Astrophysics Data System (ADS)

    Li, Yin-Qi; Li, Zi-Long; Yu, Xing; Langmuir, Charles H.; Santosh, M.; Yang, Shu-Feng; Chen, Han-Lin; Tang, Zhong-Li; Song, Biao; Zou, Si-Yuan

    2014-09-01

    The Tarim continental flood basalts (CFBs) provide important clues about the genesis and magmatic evolution of the Early Permian Tarim Large Igneous Province (Tarim LIP) in northwestern China. Here we present results of LA-MC-ICPMS Lu-Hf isotope analysis on Early Permian (ca. 290 Ma) zircons extracted from the Tarim CFBs in the Keping area, northwest of the Tarim Basin. Zircons from two sub-groups of Keping basalts (Groups 1a and 1b) have similar Lu-Hf isotopic compositions and exhibit a relatively large range of 176Hf/177Hf ratios between 0.282422 and 0.282568. Their negative εHf(t) values (- 6.8-- 1.4) are generally lower than the whole-rock εHf(t) values of their host basalts (- 2.8-2.1), and are distinct from other known intrusive rocks (- 0.3-7.1) in the Tarim LIP and their hosted zircons (4.9-8.8). Systematic studies of Hf isotopic data from Tarim and its adjacent regions reveal that these zircons are probably xenocrysts, sourced from coeval igneous rocks in the South Tianshan Orogen (e.g., the Lower Permian Xiaotikanlike Formation volcanic and pyroclastic rock suite). This, together with the presence of Precambrian zircons in Keping basalts, clearly indicates crustal contamination during their eruptions and provides hints about the potential contaminant sources. Geochemical modeling further suggests that the earlier erupted Group 1b basalts experienced more contamination, predominantly by some high Th-U-Pb rock components, most likely from the South Tianshan Orogen. The later erupted Group 1a basalts in the Keping area have been less contaminated with mainly the Tarim Precambrian rocks. Another group of the Tarim CFBs in the Northern Tarim Uplift (Group 2) appears to have undergone negligible crustal contamination but possesses evidence for variable source compositions. The modeling also indicates that the uncontaminated parental magmas of various Tarim LIP rocks (from the picrites and basalts to ultramafic-mafic and syenitic intrusive rocks) exhibit a

  16. Variable mineralization processes during the formation of the Permian Hulu Ni-Cu sulfide deposit, Xinjiang, Northwestern China

    NASA Astrophysics Data System (ADS)

    Zhao, Yun; Xue, Chunji; Zhao, Xiaobo; Yang, Yongqiang; Ke, Junjun; Zu, Bo

    2016-08-01

    The Permian Hulu Ni-Cu sulfide deposit is located at the southern margin of the Central Asian Orogenic Belt (CAOB) in Northern Xinjiang, Northwestern China. The host intrusion of the Hulu deposit is composed of a layered mafic-ultramafic sequence and a dike-like unit. The layered sequence is composed of harzburgite, lherzolite, pyroxenite, gabbro, gabbrodiorite and diorite. The dike-like body comprises lherzolite and gabbro. Sulfide orebodies occur mainly within the harzburgite, pyroxenite and lherzolite at the base of the layered sequence and within the lherzolite in the dike-like body. Sulfide mineralization from the Hulu deposit shows significant depletion of PGE relative to Cu and Ni. These elements show good positive correlations with S in the sulfide mineralization from the dike-like unit but relatively weak correlations in the sulfide mineralization from the layered sequence. The sulfide mineralization from the layered unit shows excellent positive correlations between Ir and Os, Ru or Rh, and poor relationships between Ir and Pt or Pd. On the contrary, sulfide mineralization from the dike-like unit shows good correlations in the diagrams of Os, Ru, Rh, Pt and Pd against Ir. Both high Cu/Pd ratios (8855-481,398) and our modeling indicate that PGE depletion resulted from sulfide removal in a deep staging magma chamber. The evolved PGE-depleted magmas then ascended to the shallower magma chamber and became sulfide saturation due to crustal contamination. Both low Se/S ratios (33.5 × 10-6-487.5 × 10-6) and a negative correlation between Se/S and Cu/Pd ratios are consistent with the addition of crustal S. A large number of sulfide liquids segregated with minor crystallization of monosulfide solid solution (MSS) in the shallower magma chamber. When new magma pulses with unfractionated sulfide droplets entered the shallower magma chamber, the sulfide slurry containing crystallized MSS may be disrupted and mixed with the unfractionated sulfide droplets. The

  17. Variation in Foliar δ13C of Desert Plant Reaumuria soongorica (Pall.) Maxim. among Different Environments in Northwestern China

    NASA Astrophysics Data System (ADS)

    Ma, J.; Pendall, E.; Chen, F.

    2008-12-01

    Reaumuria soongorica is a dominant desert shrub species in arid regions of northwest China, it playing an important role in the maintenance of the stability and continuity of desert ecosystem. The objectives of this study were to investigate the distribution characteristics of foliar δ13C value in R. soongorica, establish the correlations between foliar characteristics and environmental factors, and identify the major factor controlling the variations of foliar δ13C among different environments. Leaves of R. soongorica were collected from 21 natural populations in its major distribution area in northwestern China, across a range of mean annual precipitation from 27 to 328 mm, at altitudes from 394 to 1987 m above sea level, at latitudes from 36°N to 45°N and at longitudes from 81°E to 107°E. We measured the leaf nitrogen (LN), phosphorus (LP), potassium content (LK), leaf water content (LWC) and foliar δ13C in leaves of 407 individuals, and the soil physicochemical properties including nitrogen (SN), phosphorus (SP), soil organic matter (SOM), soil water contents (SWC) and total dissolved solids (TDS). Mean annual precipitation (MAP), mean annual temperature (MAT), evaporation, mean relative humidity (MRH) and duration of sunshine (DS), were collected from the Cold and Arid Environmental and Engineering Research Institute, Chinese Academy of Sciences. We observed that the foliar δ13C values increased significantly with the decreasing of MAP (r = -0.623, P = 0.003) and MRH(r = -0.702, P = 0.002), and decreased with decreasing DS and evaporation. No significant correlation with MAT was detected in δ13C values of R. soongorica. The correlations between foliar δ13C value and the soil factors demonstrated that the foliar δ13C values in R. soongorica significantly increased with the decreasing SWC (r = - 0.470, P = 0.037) and increasing TDS (r = 0.507, P = 0.022) in soil. There were no significant correlations between the foliar δ13C values and soil pH, total

  18. A new species of the genus Leptobrachium (Anura: Megophryidae) from the Gaoligongshan Mountain Range, China.

    PubMed

    Yang, Jian-Huan; Wang, Ying-Yong; Chan, Bosco Pui-Lok

    2016-01-01

    We describe a new species of the genus Leptobrachium from the Gaoligongshan Mountain Range, Yunnan Province of China based on molecular and morphological evidences. The new species, Leptobrachium tengchongense sp. nov., can be distinguished from its congeners by a combination of the following characters: (1) relatively small size (adult males SVL 41.7-51.5 mm); (2) head width slightly larger than head length; (3) tympanum indistinct; (4) two palmar tubercles oval and distinct, inner one larger than outer one; (5) sexually active males without spines on the upper lip; (6) dorsal skin smooth with distinct network of ridges; (7) dorsum pinkish grey and scattered with irregular black markings; (8) venter dark purplish-gray with numerous small white spots on tubercles, solid white chest; (9) iris bicolored, upper one-third light blue, lower two-third dark brown. With the description of the new species, the number of Leptobrachium species currently known from China adds up to ten. PMID:27515651

  19. Features and geotectonic evolution of the Alxa Terrane at North Qilian Mountains in China

    NASA Astrophysics Data System (ADS)

    Wu, Xiaozhi; Zhengmin, Min

    2015-04-01

    The Alxa Terrane in west China, covered with Badain Jaran and Tengger Deserts at the earth's surface, lies geographically on the north of the Qilian-Mountains Structural Belt and the Qinghai-Tibet Plateau with intense tectonic activities. The Mongolian Plateau with Cenozoic activities and the Ordos Plateau are on the north and east of the terrane separately. Tectonically the terrane lies among the Central Asian Orogenic Belt, the Qilian-Qinling Orogenic Belt in the Tarim Plate, and the North China Craton. In view of its special geotectonic location, the knowledge about the Alxa Terrane generation and evolution would be significant to the understanding of plates and terranes convergence and evolution in west China and to hydrocarbon exploration in those small and medium basins in the Hexi Corridor. The conclusions include (1) the Alxa Terrane is a component part in the west of the North China Plate instead of a part separated from the Tarim Plate. Neoarchean rocks occurring in the Beidashan area in west Alxa are mainly composed of granodiorite gneiss with typical TTG gneiss features. The age of the magmatic zircon nucleus is about 2522±30 Ma, which is basically consistent with that of TFG gneiss pervasively distributing in the North China Craton; (2) the Alxa Terrane was a relatively isolated small terrane in the Archaean and Proterozoic Eras. The lithologies of the crystalline basement are different from those in the Tarim and North China Plates. Tectothermal events took place 800-1000 Ma and 400-600 Ma ago separately in Alxa, which had few signatures in the North China Plate. The North China Plate and the Alxa Terrane converged in the south and diverged in the north due to the impact of the Caledonian Movement and then merged at the early stage of the Middle Ordovician. During the Middle Hercynian Movement, the Paleoasian Ocean in the north closed and new crust appeared in the Early Permian to form the trench-arc-basin system at the north margin. During the Late

  20. Drought history inferred from tree ring δ 13C and δ 18O in the central Tianshan Mountains of China and linkage with the North Atlantic Oscillation

    NASA Astrophysics Data System (ADS)

    Xu, Guobao; Liu, Xiaohong; Qin, Dahe; Chen, Tuo; Sun, Weizhen; An, Wenling; Wang, Wenzhi; Wu, Guoju; Zeng, Xiaomin; Ren, Jiawen

    2014-05-01

    Annual tree ring δ 18O and δ 13C chronologies from 1790 to 2008 were established using Tianshan spruce ( Picea schrenkiana) in the central Tianshan Mountains of northwestern China. Temperature has a positive effect on tree ring δ 18O and δ 13C in the study area, while precipitation and relative humidity have negative effects. The standardized precipitation-evapotranspiration index (SPEI) considered all of these effects and was significantly negatively correlated with tree ring δ 18O and δ 13C. We combined the tree ring δ 18O and δ 13C series to reconstruct the past 192 years of SPEI, which accounted for about 46 % of the total variance of SPEI from 1950 to 2006. The reconstruction showed good spatial agreement with gridded data in Palmer Drought Severity Index and precipitation and an inverse relationship with temperature. Our SPEI reconstruction reveals several wet and dry periods over the past 192 years and has good agreement with other drought records. Wavelet analysis showed quasi-periodic 10-, 20-, 30-, and 70-year fluctuations in the reconstruction. The 10-, 20-, and 30-year periodicities may reflect the potential influence of North Atlantic Oscillation (NAO). Overall, this study indicates that the SPEI is a potential drought index, and the winter NAO affects regional moisture conditions in the long term.

  1. Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China.

    PubMed

    Zhang, Lei; Jin, Lianji; Zhao, Tianliang; Yin, Yan; Zhu, Bin; Shan, Yunpeng; Guo, Xiaomei; Tan, Chenghao; Gao, Jinhui; Wang, Haoliang

    2015-12-15

    To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport. PMID:26318811

  2. Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China.

    PubMed

    Zhang, Lei; Jin, Lianji; Zhao, Tianliang; Yin, Yan; Zhu, Bin; Shan, Yunpeng; Guo, Xiaomei; Tan, Chenghao; Gao, Jinhui; Wang, Haoliang

    2015-12-15

    To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport.

  3. Alpine Glacier Change in the Eastern Altun Mountains of Northwest China during 1972-2010

    PubMed Central

    Yu, Xinyang; Lu, Changhe

    2015-01-01

    Accurately mapping and monitoring glacier changes over decades is important for providing information to support sustainable use of water resource in arid regions of northwest China. Since 1970, glaciers in the Eastern Altun Mountains showed remarkable recession. Further study is indispensable to indicate the extent and amplitude of glacial change at basin and individual glacier scale. In this study, spatiotemporal glacier changes referring to the year 1972, 1990, 2000 and 2010 were studied for the Eastern Altun Mountains using Landsat MSS/TM/ETM+ images and glacier volume-area scaling. The results demonstrated that the total area and volume of glaciers in EAMs decreased significantly by 10.70±0.57 km² (19.56±10.41%) and 0.61±0.03 km³ (23.19±11.40%) during 1972–2010, respectively. More than half of the total receding area occurred during 1990–2000, primarily due to higher temperature increasing. However, varied response of individual glaciers indicated that glacier change was also affected by glacier dynamics, which was related to local topography. In addition, five glaciers unrecorded in the glacier inventory of China were reported in this study. PMID:25723669

  4. Alpine glacier change in the Eastern Altun mountains of Northwest China during 1972-2010.

    PubMed

    Yu, Xinyang; Lu, Changhe

    2015-01-01

    Accurately mapping and monitoring glacier changes over decades is important for providing information to support sustainable use of water resource in arid regions of northwest China. Since 1970, glaciers in the Eastern Altun Mountains showed remarkable recession. Further study is indispensable to indicate the extent and amplitude of glacial change at basin and individual glacier scale. In this study, spatiotemporal glacier changes referring to the year 1972, 1990, 2000 and 2010 were studied for the Eastern Altun Mountains using Landsat MSS/TM/ETM+ images and glacier volume-area scaling. The results demonstrated that the total area and volume of glaciers in EAMs decreased significantly by 10.70±0.57 km² (19.56±10.41%) and 0.61±0.03 km³ (23.19±11.40%) during 1972-2010, respectively. More than half of the total receding area occurred during 1990-2000, primarily due to higher temperature increasing. However, varied response of individual glaciers indicated that glacier change was also affected by glacier dynamics, which was related to local topography. In addition, five glaciers unrecorded in the glacier inventory of China were reported in this study.

  5. Genetic differentiation between red deer from different sample sites on the Tianshan Mountains (Cervus elaphus), China.

    PubMed

    Zhou, Can-Lin; Turdy, Risalat; Halik, Mahmut

    2015-02-01

    About 273 individuals were identified from 471 fecal samples from six different red deer populations in China. The genetic structure showed that the red deer from the western and eastern Tianshan Mountains was different. A total number of 12 haplotypes were defined by 97 variable sites by the control region (CR), and 10 haplotypes were defined by 34 variable sites by cytochrome b. There was no haplotype sharing between red deer populations from western and eastern Tianshan Mountains by the CR and the cytochrome b. The red deer populations from west were clade with wapiti from North American and red deer from Siberia, while red deer populations from east were clade with red deer from Crimea in Pleistocene rather than west at present. The result of NETWORK also showed that red deer populations from western and eastern Tianshan Mountains were different. The haplotype and the Fst value between western and eastern Tianshan red deer were significantly different. The AMOVA analysis showed that 97.34% and 1.14% of the total genetic variability were found within populations and among populations within groups, respectively, by microsatellite. AMOVA for mitochondria showed that most of the variance was explained among-group. The Fst, pairwise distance, and phylogenetic relationship result showed that red deer between western and eastern Tianshan were more different than some of the red deer from North-Asia, South-Asia, East-Asia, and wapiti. All data from this study do support that the genetic characteristics of red deer between western and eastern Tianshan Mountains by microsatellite, control region, and cytochrome b were different.

  6. The crustal structure from the Altai Mountains to the Altyn Tagh fault, northwest China

    USGS Publications Warehouse

    Wang, Y.; Mooney, W.D.; Yuan, X.; Coleman, R.G.

    2003-01-01

    We present a new crustal section across northwest China based on a seismic refraction profile and geologic mapping. The 1100-km-long section crosses the southern margin of the Chinese Altai Mountains, Junggar Accretional Belt and eastern Junggar basin, easternmost Tianshan Mountains, and easternmost Tarim basin. The crustal velocity structure and Poisson's ratio (??), which provide a constraint on crustal composition, were determined from P and S wave data. Despite the complex geology, the crustal thickness along the entire profile is nearly uniform at 50 km. The thickest crust (56 km) occurs at the northern end of the profile beneath the Altai Mountains and the thinnest (46 km) crust is beneath the Junggar basin. Beneath surficial sediments, the crust is found to have three layers with P wave velocities (Vp) of 6.0-6.3, 6.3-6.6, and 6.9-7.0 km/s, respectively. The southern half of the profile, including the eastern Tianshan Mountains and eastern margin of the Tarim basin, shows low P wave velocities and ?? = 0.25 to a depth of 30 km, which suggests a quartz-rich, granitic upper crustal composition. The northern half of the profile below the Altai Mountains and Junggar Accretional Belt has a higher Poisson's ratio of ?? = 0.26-0.27 to a depth of 30 km, indicative of an intermediate crustal composition. The entire 1100-km-long profile is underlain by a 15-30 km thick high velocity (6.9-7.0 km/s; ?? = 0.26-0.28) lower-crustal layer that we interpret to have a bulk composition of mafic granulite. At the southern end of the profile, a 5-km-thick midcrustal low-velocity layer (Vp = 5.9 km/s, ?? = 0.25) underlies the Tianshan and the region to the south, and may be indicative of a near-horizontal detachment interface. Pn velocities are ???7.7-7.8 km/s between the Tianshan and the Junggar basin, and ???7.9-8.0 km/s below the Altai Mountains and eastern margin of the Tarim basin. We interpret the consistent three-layer stratification of the crust to indicate that the crust

  7. A closure study of aerosol optical properties at a regional background mountainous site in Eastern China.

    PubMed

    Yuan, Liang; Yin, Yan; Xiao, Hui; Yu, Xingna; Hao, Jian; Chen, Kui; Liu, Chao

    2016-04-15

    There is a large uncertainty in evaluating the radiative forcing from aerosol-radiation and aerosol-cloud interactions due to the limited knowledge on aerosol properties. In-situ measurements of aerosol physical and chemical properties were carried out in 2012 at Mt. Huang (the Yellow Mountain), a continental background mountainous site in eastern China. An aerosol optical closure study was performed to verify the model outputs by using the measured aerosol optical properties, in which a spherical Mie model with assumptions of external and core-shell mixtures on the basis of a two-component optical aerosol model and high size-segregated element carbon (EC) ratio was applied. Although the spherical Mie model would underestimate the real scattering with increasing particle diameters, excellent agreement between the calculated and measured values was achieved with correlation coefficients above 0.98. Sensitivity experiments showed that the EC ratio had a negligible effect on the calculated scattering coefficient, but largely influenced the calculated absorption coefficient. The high size-segregated EC ratio averaged over the study period in the closure was enough to reconstruct the aerosol absorption coefficient in the Mie model, indicating EC size resolution was more important than time resolution in retrieving the absorption coefficient in the model. The uncertainties of calculated scattering and absorption coefficients due to the uncertainties of measurements and model assumptions yielded by a Monte Carlo simulation were ±6% and ±14% for external mixture and ±9% and ±31% for core-shell mixture, respectively. This study provided an insight into the inherent relationship between aerosol optical properties and physicochemical characteristics in eastern China, which could supplement the database of aerosol optical properties for background sites in eastern China and provide a method for regions with similar climate.

  8. Major-element geochemistry of the Silent Canyon-Black Mountain peralkaline volcanic centers, northwestern Nevada Test Site: applications to an assessment of renewed volcanism

    USGS Publications Warehouse

    Crowe, Bruce M.; Sargent, Kenneth A.

    1979-01-01

    The Silent Canyon and Black Mountain volcanic centers are located in the northern part of the Nevada Test Site. The Silent Canyon volcanic center is a buried cauldron complex of Miocene age (13-15 m.y.). Black Mountain volcanic center is an elliptical-shaped cauldron complex of late Miocene age. The lavas and tuffs of the two centers comprise a subalkaline-peralkaline association. Rock types range from quartz normative subalkaline trachyte and rhyolite to peralkaline comendite. The Gold Flat Member of the Thirsty Canyon Tuff (Black Mountain) is a pantellerite. The major-element geochemistry of the Black Mountain-Silent Canyon volcanic centers differs in the total range and distribution of Si02, contents, the degree of peralkalinity (molecular Na2O+K2O>Al2O3) and in the values of total iron and alumina through the range of rock types. These differences indicate that the suites were unrelated and evolved from differing magma bodies. The Black Mountain volcanic cycle represents a renewed phase of volcanism following cessation of the Timber Mountain-Silent Canyon volcanic cycles. Consequently, there is a small but numerically incalculable probability of recurrence of Black Mountain-type volcanism within the Nevada Test Site region. This represents a potential risk with respect to deep geologic storage of high-level radioactive waste at the Nevada Test Site.

  9. Recent atmospheric dust deposition in an ombrotrophic peat bog in Great Hinggan Mountain, Northeast China.

    PubMed

    Bao, Kunshan; Xing, Wei; Yu, Xiaofei; Zhao, Hongmei; McLaughlin, Neil; Lu, Xianguo; Wang, Guoping

    2012-08-01

    Recent deposition of atmospheric soil dust (ASD) was studied using (210)Pb-dated Sphagnum-derived peat sequences from Great Hinggan Mountain in northeast China. Physicochemical indices of peat including dry bulk density, water content, ash content, total organic carbon and mass magnetic susceptibility were measured. Acid-insoluble concentration of lithogenic metals (Al, Ca, Fe, Mn, V and Ti) were measured using ICP-AES. The basic physicochemical properties were used to assess the peat trophic status and indicated that the sections above 45-60 cm are rain-fed peat. A continuous record of ASD fluxes over the past 150 years was reconstructed based on the geochemical data obtained from the ombrotrophic zone, and the average input rate of ASD is 13.4-68.1 g m(-2) year(-1). The source of soil dust deposited in peat was dominated by the long-range transport of mineral aerosol from the drylands in north China and Mongolia. The temporal variation of ASD fluxes in the last 60 years coincides well with the meteorological records of dust storm frequency during 1954-2002 in north China. This suggests that the reconstructed sequence of atmospheric dust deposition is reliable and we can look back in time at the dust evolution before 1949. Dust storm events were observed occasionally in the late Qing dynasty, and their frequency and intensity were smaller than dust weather occurring in recent times. Four peaks of ASD fluxes were distinguished and correlated with the historical events at that time. This study presents the first atmospheric soil dust data in peat records in northeast China, and complements a global database of peat bog archives of atmospheric deposition. The results reflect the patterns of local environmental change over the past century in north China and will be helpful in formulating policies to achieve sustainable and healthy development.

  10. Recent atmospheric dust deposition in an ombrotrophic peat bog in Great Hinggan Mountain, Northeast China.

    PubMed

    Bao, Kunshan; Xing, Wei; Yu, Xiaofei; Zhao, Hongmei; McLaughlin, Neil; Lu, Xianguo; Wang, Guoping

    2012-08-01

    Recent deposition of atmospheric soil dust (ASD) was studied using (210)Pb-dated Sphagnum-derived peat sequences from Great Hinggan Mountain in northeast China. Physicochemical indices of peat including dry bulk density, water content, ash content, total organic carbon and mass magnetic susceptibility were measured. Acid-insoluble concentration of lithogenic metals (Al, Ca, Fe, Mn, V and Ti) were measured using ICP-AES. The basic physicochemical properties were used to assess the peat trophic status and indicated that the sections above 45-60 cm are rain-fed peat. A continuous record of ASD fluxes over the past 150 years was reconstructed based on the geochemical data obtained from the ombrotrophic zone, and the average input rate of ASD is 13.4-68.1 g m(-2) year(-1). The source of soil dust deposited in peat was dominated by the long-range transport of mineral aerosol from the drylands in north China and Mongolia. The temporal variation of ASD fluxes in the last 60 years coincides well with the meteorological records of dust storm frequency during 1954-2002 in north China. This suggests that the reconstructed sequence of atmospheric dust deposition is reliable and we can look back in time at the dust evolution before 1949. Dust storm events were observed occasionally in the late Qing dynasty, and their frequency and intensity were smaller than dust weather occurring in recent times. Four peaks of ASD fluxes were distinguished and correlated with the historical events at that time. This study presents the first atmospheric soil dust data in peat records in northeast China, and complements a global database of peat bog archives of atmospheric deposition. The results reflect the patterns of local environmental change over the past century in north China and will be helpful in formulating policies to achieve sustainable and healthy development. PMID:22664536

  11. The chemical characteristics of precipitation in Lushan mountain, east of China in springtime

    SciTech Connect

    Yuanhang Zhang; Yu Win

    1996-12-31

    A comprehensive filed measurement was set up in Lushan mountain, east China in springtime, in March 1993. Gaseous SO{sub 2}, NO{sub x}, O{sub 3}, TSP and the chemical composition of different precipitation were measured. One of objective of the field measurement was to study the acidification mechanism of front precipitation, which frequently happens in Yangtze River watershed in springtime. Combined with the observations in 1987 and 1989, the results indicate: (1) As a tourism area, the air in Lushan mountain is relatively clean, SO{sub 2} average concentration is 2.56 {mu}g/m{sup 3}, NO{sub x} 1.26, NH{sub 3} 1.17 {mu}g/m{sup 3}, and 03 37.5 ppb. HNO{sub 3} is not detected. The concentrations of water soluble species were low. Compared with that in 1987, SO{sub 2} concentration increases quickly. (2) Precipitation is getting more and more acidic since 1987. Average pH of rainwater and cloud water is 4.19 and 4.26 respectively. The solid precipitation is not so acidic, the average pH of snow is 4.87. The acidic substance increase and alkali substance decrease. 2 The SO{sup 2-}{sub 4}/ NO{sup -}{sub 3} ratio was 3.2, which was much lower than that in 1987. HNO{sub 3} plays important role in acidification of precipitation in Lushan 2-mountain. However, the ratio of SO{sup 2- }{sub 4}/NO{sup -}{sub 3} in aerosol is 8.7 is much higher than that in precipitation. (4) Abundant oxidant is in precipitation. Aqueous H{sub 2}O{sub 2} was detected in 87% of samples. Thus, the precipitation will get more acidic if local SO{sub 2} concentration increases. (5) The concentrations of cation and anion in rain water are 1/6-1/8 of those in cloud water and 1/2-1/5 of those in snow. (6) Taking local air pollution level, weather pattern and composition of precipitation into account, long distance of acidic substances is strongly suggested by the measurement. (7) The measurement results were compared with those in other mountains in south China.

  12. Pooled versus separate tree-ring δD measurements, and implications for reconstruction of the Arctic Oscillation in northwestern China.

    PubMed

    Liu, Xiaohong; An, Wenling; Treydte, Kerstin; Wang, Wenzhi; Xu, Guobao; Zeng, Xiaomin; Wu, Guoju; Wang, Bo; Zhang, Xuanwen

    2015-04-01

    Stable hydrogen isotope ratios (δD) in tree rings are an attractive but still rarely explored terrestrial archive of past climatic information. Because the preparation of the cellulose nitrate for δD measurements requires more wood and a longer preparation time than preparation techniques for other isotopes in cellulose (δ18O or δ13C), it is challenging to obtain high-resolution records, especially for slow-growing trees at high elevations and in boreal regions. Here, we tested whether annually pooled samples of Qinghai spruce (Picea crassifolia Kom.) trees from northwestern China provided results similar to those derived as the mean of individual measurements of the same trees and whether the resulting chronologies recorded useful climate information. Inter-tree variability of δD was higher than that of measured ring width for the same trees. We found higher and significant coherence between pooled and mean isotope chronologies than that among the individual series. It showed a logarithmic relationship between ring mass and δD; however, accounting for the influence of ring mass on δD values only slightly improved the strength of climatic signals in the pooled records. Tree-ring δD was significantly positively correlated with the mean, maximum, and minimum temperatures during the previous winter and with maximum temperature during the current August, and significantly negatively correlated with precipitation in the previous November to January and the current July. The winter climate signal seems to dominate tree-ring δD through the influence of large-scale atmospheric circulation patterns, i.e. the Arctic Oscillation. These results will facilitate reconstruction of winter atmospheric circulation patterns over northwestern China based on a regional tree-ring δD networks.

  13. Pooled versus separate tree-ring δD measurements, and implications for reconstruction of the Arctic Oscillation in northwestern China.

    PubMed

    Liu, Xiaohong; An, Wenling; Treydte, Kerstin; Wang, Wenzhi; Xu, Guobao; Zeng, Xiaomin; Wu, Guoju; Wang, Bo; Zhang, Xuanwen

    2015-04-01

    Stable hydrogen isotope ratios (δD) in tree rings are an attractive but still rarely explored terrestrial archive of past climatic information. Because the preparation of the cellulose nitrate for δD measurements requires more wood and a longer preparation time than preparation techniques for other isotopes in cellulose (δ18O or δ13C), it is challenging to obtain high-resolution records, especially for slow-growing trees at high elevations and in boreal regions. Here, we tested whether annually pooled samples of Qinghai spruce (Picea crassifolia Kom.) trees from northwestern China provided results similar to those derived as the mean of individual measurements of the same trees and whether the resulting chronologies recorded useful climate information. Inter-tree variability of δD was higher than that of measured ring width for the same trees. We found higher and significant coherence between pooled and mean isotope chronologies than that among the individual series. It showed a logarithmic relationship between ring mass and δD; however, accounting for the influence of ring mass on δD values only slightly improved the strength of climatic signals in the pooled records. Tree-ring δD was significantly positively correlated with the mean, maximum, and minimum temperatures during the previous winter and with maximum temperature during the current August, and significantly negatively correlated with precipitation in the previous November to January and the current July. The winter climate signal seems to dominate tree-ring δD through the influence of large-scale atmospheric circulation patterns, i.e. the Arctic Oscillation. These results will facilitate reconstruction of winter atmospheric circulation patterns over northwestern China based on a regional tree-ring δD networks. PMID:25590539

  14. Strategies for the prevention of acute mountain sickness and treatment for large groups making a rapid ascent in China.

    PubMed

    Luo, Yongjun; Yang, Xiaohong; Gao, Yuqi

    2013-10-30

    Approximately 26.8% of China's land area has an elevation of 3000 m above sea level or higher. Because of recent demands for economic development and new construction in highland areas, many people have relocated from the plains to high plateau regions and have to face the possibility of contracting acute mountain sickness. Therefore, prevention and treatment strategies are necessary to reduce the incidence of acute mountain sickness in people who rapidly ascend to plateau areas. This paper describes the Chinese experience when large numbers of people moved to the plateau and the steps that were taken to deal with this illness. These steps included implementing basic prevention measures, increasing medical awareness among populations ascending to high altitudes, and installing standardized medical management systems to prevent and treat acute mountain sickness before, during, and after ascent. The incidence of acute mountain sickness can be reduced by improving prevention and treatment and by implementing the recommendations described in this manuscript.

  15. [Relationships of forest fire with lightning in Daxing' anling Mountains, Northeast China].

    PubMed

    Lei, Xiao-Li; Zhou, Guang-Sheng; Jia, Bing-Rui; Li, Shuai

    2012-07-01

    Forest fire is an important factor affecting forest ecosystem succession. Recently, forest fire, especially forest lightning fire, shows an increasing trend under global warming. To study the relationships of forest fire with lightning is essential to accurately predict the forest fire in time. Daxing' anling Mountains is a region with high frequency of forest lightning fire in China, and an important experiment site to study the relationships of forest fire with lightning. Based on the forest fire records and the corresponding lightning and meteorological observation data in the Mountains from 1966 to 2007, this paper analyzed the relationships of forest fire with lightning in this region. In the period of 1966-2007, both the lightning fire number and the fired forest area in this region increased significantly. The meteorological factors affecting the forest lighting fire were related to temporal scales. At yearly scale, the forest lightning fire was significantly correlated with precipitation, with a correlation coefficient of -0.489; at monthly scale, it had a significant correlation with air temperature, the correlation coefficient being 0.18. The relationship of the forest lightning fire with lightning was also related to temporal scales. At yearly scale, there was no significant correlation between them; at monthly scale, the forest lightning fire was strongly correlated with lightning and affected by precipitation; at daily scale, a positive correlation was observed between forest lightning fire and lightning when the precipitation was less than 5 mm. According to these findings, a fire danger index based on ADTD lightning detection data was established, and a forest lightning fire forecast model was developed. The prediction accuracy of this model for the forest lightning fire in Daxing' anling Mountains in 2005-2007 was > 80%.

  16. [Characteristics and impact factors of O3 concentrations in mountain background region of East China].

    PubMed

    Su, Bin-Bin

    2013-07-01

    The O3 concentrations were measured online from March 2011 to February 2012 at the national atmospheric background monitoring station in Wuyishan of Fujian Province to discuss the characteristic of O3 concentrations and the impact factors in forest and mountain background region of East China. HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) Model was used to investigate the potential sources of particulates during the pollution episodes. The results showed that the background concentration of O3 was (87.9 +/- 34.1) microg x m(-3). Seasonal variations of O3 loadings were observed, and the loadings decreased in the order spring > autumn > summer > winter. Analysis of correlation between O3 and other gas pollutants suggested regional transportation, stratospheric injection and photochemical production were the major sources of O3 in Wuyishan background station. The episodes were related with transportations of air parcel from Yangtze River Delta region, Pearl River Delta region and the high altitudes.

  17. Diversity of Woodland Communities and Plant Species along an Altitudinal Gradient in the Guancen Mountains, China

    PubMed Central

    Meng, Dongping; Zhang, Jin-Tun; Li, Min

    2012-01-01

    Study on plant diversity is the base of woodland conservation. The Guancen Mountains are the northern end of Luliang mountain range in North China. Fifty-three quadrats of 10 m × 20 m of woodland communities were randomly established along an altitudinal gradient. Data for species composition and environmental variables were measured and recorded in each quadrat. To investigate the variation of woodland communities, a Two-Way Indicator Species Analysis (TWINSPAN) and a Canonical Correspondence Analysis (CCA) were conducted, while species diversity indices were used to analyse the relationships between species diversity and environmental variables in this study. The results showed that there were eight communities of woodland vegetation; each of them had their own characteristics in composition, structure, and environment. The variation of woodland communities was significantly related to elevation and also related to slope, slope aspect, and litter thickness. The cumulative percentage variance of species-environment relation for the first three CCA axes was 93.5%. Elevation was revealed as the factor which most influenced community distribution and species diversity. Species diversity was negatively correlated with elevation, slope aspect, and litter thickness, but positively with slope. Species richness and heterogeneity increased first and then decreased but evenness decreased significantly with increasing elevation. Species diversity was correlated with slope, slope aspect, and litter thickness. PMID:22566768

  18. Forest dynamics and their phenological response to climate warming in the Khingan Mountains, northeastern China.

    PubMed

    Cai, Hongyan; Zhang, Shuwen; Yang, Xiaohuan

    2012-11-01

    The Khingan Mountain region, the most important and typical natural foci of tick-borne encephalitis (TBE) in China, is the largest and northernmost forest area and the one more sensitive to climate change. Taking this region as the study area, we investigated the spatio-temporal dynamics of deciduous broadleaf forest (DBF) and its phenology changes in relation to climate change and elevation. Based on MODIS Enhanced Vegetation Index (EVI) time series over the period of 2001 to 2009, the start-of-season (SOS), length-of-season (LOS) and another two vegetation variables (seasonal amplitude (SA) and integrated EVI (SI)) were derived. Over the past decade, the DBF in Khingan Mountains has generally degraded and over 65% of DBF has experienced negative SA and SI trends. Earlier trends in SOS and longer trends in LOS for DBF were observed, and these trends were mainly caused by climate warming. In addition, results from our analysis also indicated that the effects of temperature on DBF phenology were elevation dependent. The magnitude of advancement in SOS and extension in LOS with temperature increase significantly increased along a raising elevation gradient.

  19. Soil bacterial diversity patterns and drivers along an elevational gradient on Shennongjia Mountain, China.

    PubMed

    Zhang, Yuguang; Cong, Jing; Lu, Hui; Li, Guangliang; Xue, Yadong; Deng, Ye; Li, Hui; Zhou, Jizhong; Li, Diqiang

    2015-07-01

    Understanding biological diversity elevational pattern and the driver factors are indispensable to develop the ecological theories. Elevational gradient may minimize the impact of environmental factors and is the ideal places to study soil microbial elevational patterns. In this study, we selected four typical vegetation types from 1000 to 2800 m above the sea level on the northern slope of Shennongjia Mountain in central China, and analysed the soil bacterial community composition, elevational patterns and the relationship between soil bacterial diversity and environmental factors by using the 16S rRNA Illumina sequencing and multivariate statistical analysis. The results revealed that the dominant bacterial phyla were Acidobacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Verrucomicrobia, which accounted for over 75% of the bacterial sequences obtained from tested samples, and the soil bacterial operational taxonomic unit (OTU) richness was a significant monotonous decreasing (P < 0.01) trend with the elevational increasing. The similarity of soil bacterial population composition decreased significantly (P < 0.01) with elevational distance increased as measured by the Jaccard and Bray-Curtis index. Canonical correspondence analysis and Mantel test analysis indicated that plant diversity and soil pH were significantly correlated (P < 0.01) with the soil bacterial community. Therefore, the soil bacterial diversity on Shennongjia Mountain had a significant and different elevational pattern, and plant diversity and soil pH may be the key factors in shaping the soil bacterial spatial pattern.

  20. Impacts of mountains on black carbon aerosol under different synoptic meteorology conditions in the Guanzhong region, China

    NASA Astrophysics Data System (ADS)

    Zhao, Shuyu; Tie, Xuexi; Cao, Junji; Zhang, Qiang

    2015-10-01

    The Xi'an City and the surrounding area (the Guan-Zhong-GZ region) in western China have been suffering severe air pollutions during wintertime in recent years. In-situ black carbon (BC) measurement combined with a regional dynamical and chemical model (WRF-Chem model) is used to investigate the formation of a haze episode occurred from Jan. 3rd to Jan. 13th 2013. The results show that the measured BC concentrations exhibit a large day-to-day variability. The impacts of synoptic weather systems, local meteorological parameters and mountain effect on the BC variability are studied. Because the GZ region is surrounded by two major mountains, the Loess Plateau in the north and the Qinling Mountains in the south, especially the peak of the Qinling Mountains higher than 3000 m, we particularly analyze the effects of the Qinling Mountains on the BC pollution. The analysis shows that the BC pollution in Xi'an City and the GZ region is strongly affected by the synoptic weather systems, local meteorological winds and the Qinling Mountains. Under a typical northeast wind condition, winds are blocked by the Qinling Mountains, and BC particles are trapped at the foothill of the mountains, resulting in high BC concentrations in the city of Xi'an. Under a typical east wind condition, BC particles are transported along a river valley and the foothill of the Qinling Mountains. In this case, the mountain-river valley plays a role to accelerate the east wind, resulting in a reduction of the BC pollution. Under a typical calm wind condition, the BC particles are less diffused from their source region, and there is a mountain breeze from the Qinling Mountains to the city of Xi'an, and BC particles accumulate in the city, especially in the north side of the city. This study illustrates that while locating between complicated terrain conditions, such as the GZ region, the mountains play very important roles for the formation of hazes in the region.

  1. Mountain pastures of Qilian Shan: plant communities, grazing impact and degradation status (Gansu province, NW China)

    NASA Astrophysics Data System (ADS)

    Baranova, Alina; Schickhoff, Udo; Shunli, Wang; Ming, Jin

    2015-04-01

    Qilian Mountains are the water source region for the low arid reaches of HeiHe river basin (Gansu province, NW China). Due to overstocking and overgrazing during the last decades adverse ecological ef¬fects, in particular on soil properties and hydrological cycle, are to be expected in growing land areas. Vegetation cover is very important to prevent erosion process and to sustain stable subsurface runoff and ground water flow. The aim of this research is to identify plant communities, detecting grazing-induced and spatially differentiated changes in vegetation patterns, and to evaluate status of pasture land degradation.The study area is located in the spring/autumn pasture area of South Qilian Mountains between 2600-3600 m a.s.l., covering five main vegetation types: spruce forest, alpine shrubland, shrubby grassland, mountain grassland, degraded mountain grassland. In order to analyze gradual changes in vegetation patterns along altitudinal and grazing gradients and to classify related plant communities, quantitative and qualitative relevé data were collected (coverage, species composition, abundance of unpalatable plants, plant functional types, etc.). Vegetation was classified using hierarchical cluster analyses. Indirect Detrended Correspondence Analysis (DCA) was used to analyze variation in relationships between vegetation, environmental factors, and grazing impact. According to DCA results, distribution of the plant communities was strongly affected by altitude and exposition. Grassland floristic gradients showed greater dependence on grazing impact, which correlated contrarily with soil organic content, soil moisture and pH. Highest numbers of species richness and alpha diversity were detected in alpine shrubland vegetation type. Comparing the monitoring data for the recent nine years, a trend of deterioration, species successions and shift in dominant species becomes obvious. Species indicating degrading site environmental conditions were identified

  2. A Note on the Lichen Genus Ramalina (Ramalinaceae, Ascomycota) in the Hengduan Mountains in China

    PubMed Central

    Oh, Soon-Ok; Wang, Xin Yu; Wang, Li Song; Liu, Pei Gui

    2014-01-01

    On the basis of extensive field investigation and a series of herbarium specimen identifications, we present and discuss the descriptions and distribution of 22 species of Ramalina found in the Hengduan Mountains of southwestern China. In this revisionary study, representatives of the Ramalina genus, including R. americana, R. confirmata, R. dendriscoides, R. obtusata, R. pacifica, R. pentecostii, R. peruviana, R. shinanoana, and R. subcomplanata are found for the first time in this area. In addition, R. holstii is reported for the first time China. Finally, a newly described species identified as Ramalina hengduanshanensis S. O. Oh & L. S. Wang is reported. It is characterized as growing from a narrow holdfast, solid, sparsely or richly and irregularly dichotomously branched, palmate and flattened lobes with distinctly dorsiventral appearance, surface rugose to reticulate, surface rugosely cracked, dense chondroid tissue, helmet shaped soralia at the tip. The species grows on rock and tree at the highest elevations in this area. Although very few lichen species belonging to the genus Ramalina have been collected above 4,000 m, this new species is found at this elevation. We present detailed morphological, anatomical, and chemical descriptions of this species along with molecular phylogenetic analysis of the internal transcribed spacer rDNA sequences. PMID:25346599

  3. A note on the lichen genus ramalina (ramalinaceae, ascomycota) in the hengduan mountains in china.

    PubMed

    Oh, Soon-Ok; Wang, Xin Yu; Wang, Li Song; Liu, Pei Gui; Hur, Jae-Seoun

    2014-09-01

    On the basis of extensive field investigation and a series of herbarium specimen identifications, we present and discuss the descriptions and distribution of 22 species of Ramalina found in the Hengduan Mountains of southwestern China. In this revisionary study, representatives of the Ramalina genus, including R. americana, R. confirmata, R. dendriscoides, R. obtusata, R. pacifica, R. pentecostii, R. peruviana, R. shinanoana, and R. subcomplanata are found for the first time in this area. In addition, R. holstii is reported for the first time China. Finally, a newly described species identified as Ramalina hengduanshanensis S. O. Oh & L. S. Wang is reported. It is characterized as growing from a narrow holdfast, solid, sparsely or richly and irregularly dichotomously branched, palmate and flattened lobes with distinctly dorsiventral appearance, surface rugose to reticulate, surface rugosely cracked, dense chondroid tissue, helmet shaped soralia at the tip. The species grows on rock and tree at the highest elevations in this area. Although very few lichen species belonging to the genus Ramalina have been collected above 4,000 m, this new species is found at this elevation. We present detailed morphological, anatomical, and chemical descriptions of this species along with molecular phylogenetic analysis of the internal transcribed spacer rDNA sequences. PMID:25346599

  4. Sustainable Agricultural Paradigm Of mountain-Oasis-Ecotone-Desert System in Inland Manasi River Basin, Xinjiang Province, Northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Huiming; Chen, Weiming; Dong, Xiaobin; Zhang, Xinshi

    Manasi River basin is located in the north foot of Tianshan Mountain, south edge of Zhunger Basin, central-north Xinjiang province, with typical aridfeatures of northern China. As the pressure on water resources in Manasi river basin is mounting because of rapid economic development, its conservation becomes ever more important. Climate change is another major threat to the future of water resources of Manasi river basin. How the water resourcechanges in Manasi river basin caused by glacial ablation, will affect the typical mountain-basin terrestrial ecosystems and agricultural production in Manasi river basin? What can we cope with the ecological issues caused by glacial ablation? In this paper we show how the water-saving stratagem such asconstructing reservoir in the mountainous region, building water pipes and be used in combination with the potential of water-saving resources, and build up sustainable agricultural paradigm of mountain-oasis-ecotone-desert system to coping with the glacier retreat and ablation. The potential of water-saving instudy area were calculated which presumed that if mountainous reservoirs and water pipes were built and water-saving technology were adopted, optimized eco-productive paradigm for mountain-basin system in Manasi river basin is proposed in desertification controlling, constructing artificial grassland in the oasis is the measure to protect vegetation in the downstream desert in Manasi river basin, and stopping grazing or forbidding grazing in the downstream of serious degradation in Manasi river basin.

  5. Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan Mountain Region, southern Ningxia, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China, which forms an important dividing line between landforms and bio-geographic regions. The populated part of the Liupan Mountains region has suffered tremendous ecological damages over time due to population press...

  6. Altitudinal Patterns of Species Diversity and Phylogenetic Diversity across Temperate Mountain Forests of Northern China

    PubMed Central

    Zhang, Wenxin; Huang, Dizhou; Wang, Renqing; Liu, Jian; Du, Ning

    2016-01-01

    The spatial patterns of biodiversity and their underlying mechanisms have been an active area of research for a long time. In this study, a total of 63 samples (20m × 30m) were systematically established along elevation gradients on Mount Tai and Mount Lao, China. We explored altitudinal patterns of plant diversity in the two mountain systems. In order to understand the mechanisms driving current diversity patterns, we used phylogenetic approaches to detect the spatial patterns of phylogenetic diversity and phylogenetic structure along two elevation gradients. We found that total species richness had a monotonically decreasing pattern and tree richness had a unimodal pattern along the elevation gradients in the two study areas. However, altitudinal patterns in shrub richness and herbs richness were not consistent on the two mountains. At low elevation, anthropogenic disturbances contributed to the increase of plant diversity, especially for shrubs and herbs in understory layers, which are more sensitive to changes in microenvironment. The phylogenetic structure of plant communities exhibited an inverted hump-shaped pattern along the elevation gradient on Mount Tai, which demonstrates that environmental filtering is the main driver of plant community assembly at high and low elevations and inter-specific competition may be the main driver of plant community assembly in the middle elevations. However, the phylogenetic structure of plant communities did not display a clear pattern on Mount Lao where the climate is milder. Phylogenetic beta diversity and species beta diversity consistently increased with increasing altitudinal divergence in the two study areas. However, the altitudinal patterns of species richness did not completely mirror phylogenetic diversity patterns. Conservation areas should be selected taking into consideration the preservation of high species richness, while maximizing phylogenetic diversity to improve the potential for diversification in the

  7. Altitudinal Patterns of Species Diversity and Phylogenetic Diversity across Temperate Mountain Forests of Northern China.

    PubMed

    Zhang, Wenxin; Huang, Dizhou; Wang, Renqing; Liu, Jian; Du, Ning

    2016-01-01

    The spatial patterns of biodiversity and their underlying mechanisms have been an active area of research for a long time. In this study, a total of 63 samples (20m × 30m) were systematically established along elevation gradients on Mount Tai and Mount Lao, China. We explored altitudinal patterns of plant diversity in the two mountain systems. In order to understand the mechanisms driving current diversity patterns, we used phylogenetic approaches to detect the spatial patterns of phylogenetic diversity and phylogenetic structure along two elevation gradients. We found that total species richness had a monotonically decreasing pattern and tree richness had a unimodal pattern along the elevation gradients in the two study areas. However, altitudinal patterns in shrub richness and herbs richness were not consistent on the two mountains. At low elevation, anthropogenic disturbances contributed to the increase of plant diversity, especially for shrubs and herbs in understory layers, which are more sensitive to changes in microenvironment. The phylogenetic structure of plant communities exhibited an inverted hump-shaped pattern along the elevation gradient on Mount Tai, which demonstrates that environmental filtering is the main driver of plant community assembly at high and low elevations and inter-specific competition may be the main driver of plant community assembly in the middle elevations. However, the phylogenetic structure of plant communities did not display a clear pattern on Mount Lao where the climate is milder. Phylogenetic beta diversity and species beta diversity consistently increased with increasing altitudinal divergence in the two study areas. However, the altitudinal patterns of species richness did not completely mirror phylogenetic diversity patterns. Conservation areas should be selected taking into consideration the preservation of high species richness, while maximizing phylogenetic diversity to improve the potential for diversification in the

  8. Bryophyte Species Richness and Composition along an Altitudinal Gradient in Gongga Mountain, China

    PubMed Central

    Sun, Shou-Qin; Wu, Yan-Hong; Wang, Gen-Xu; Zhou, Jun; Yu, Dong; Bing, Hai-Jian; Luo, Ji

    2013-01-01

    An investigation of terrestrial bryophyte species diversity and community structure along an altitudinal gradient from 2,001 to 4,221 m a.s.l. in Gongga Mountain in Sichuan, China was carried out in June 2010. Factors which might affect bryophyte species composition and diversity, including climate, elevation, slope, depth of litter, vegetation type, soil pH and soil Eh, were examined to understand the altitudinal feature of bryophyte distribution. A total of 14 representative elevations were chosen along an altitudinal gradient, with study sites at each elevation chosen according to habitat type (forests, grasslands) and accessibility. At each elevation, three 100 m × 2 m transects that are 50 m apart were set along the contour line, and three 50 cm × 50 cm quadrats were set along each transect at an interval of 30 m. Species diversity, cover, biomass, and thickness of terrestrial bryophytes were examined. A total of 165 species, including 42 liverworts and 123 mosses, are recorded in Gongga mountain. Ground bryophyte species richness does not show any clear elevation trend. The terrestrial bryophyte cover increases with elevation. The terrestrial bryophyte biomass and thickness display a clear humped relationship with the elevation, with the maximum around 3,758 m. At this altitude, biomass is 700.3 g m−2 and the maximum thickness is 8 cm. Bryophyte distribution is primarily associated with the depth of litter, the air temperature and the precipitation. Further studies are necessary to include other epiphytes types and vascular vegetation in a larger altitudinal range. PMID:23472146

  9. Map showing spatial and temporal relations of mountain and continental glaciations on the Northern Plains, primarily in northern Montana and northwestern North Dakota

    USGS Publications Warehouse

    Fullerton, David S.; Colton, Roger B.; Bush, Charles A.; Straub, Arthur W.

    2004-01-01

    This report is an overview of glacial limits and glacial history on the plains in northern Montana and northeastern North Dakota (long 102?-114?W.) and also in adjacent southern Alberta and Saskatchewan, Canada. In the Rocky Mountains and on the plains adjacent to the mountains in Montana, the map also depicts spatial relations of valley glaciers and piedmont ice lobes to continental ice sheets. Glacial limits east of 102?, in the United States and also in adjacent Canada, are depicted on published maps of the U.S. Geological Survey Quaternary Geologic Atlas of the United States (I-1420) map series. The limits shown here are from data compiled for the Lethbridge, Regina, Yellowstone, and Big Horn Mountains 4? x 6? quadrangles in the Quaternary Geologic Atlas series. This geospatial database has been prepared with a degree of detail appropriate for viewing at a scale of 1:1,000,000. Because of the degree of generalization required, the map is intended for regional analysis, rather than for detailed analysis in specific areas. It depicts the geographic positions of the limits of mountain and continental glaciations and the limits of selected glacial readvances. That information provides a foundation for reconstruction of geologic history and for reconstruction. The base map is simplified. Selected hydrographic features, selected towns and cities, selected physiographic features, and a grid of 1? x 2? topographic quadrangles are included to aid the reader in location of the glacial limits and other features that are depicted here on other maps at different scales. Most of the geologic data were compiled at 1:250,000 scale. The nominal reading scale of the digitized map data is 1:1,000,000. Enlargement will not restore resolution that was lost by simplification or generalization of data. Accompanying illustrations show regional directions of ice movement from Canada into the United States during maximum Illinoian glaciation, during maximum late Wisconsin glaciation

  10. Nitrous oxide fluxes from three forest types of the tropical mountain rainforests on Hainan Island, China

    NASA Astrophysics Data System (ADS)

    Bai, Zhenzhi; Yang, Gang; Chen, Huai; Zhu, Qiuan; Chen, Dexiang; Li, Yide; Wang, Xu; Wu, Zhongmin; Zhou, Guangyi; Peng, Changhui

    2014-08-01

    Tropical rainforest soil is an important source of atmospheric nitrous oxide (N2O). However, there is still considerable uncertainty about the spatial and temporal variability of N2O fluxes. To understand these fluxes, we quantified the annual N2O emissions from three tropical mountain rainforests (primary mountain rainforest, PMR; secondary mountain rainforest, SMR; and Podocarpus imbricatus plantation, PIP) in the Jianfengling National Natural Reserve on Hainan Island, China. The average of N2O emissions in this area was 2.52 ± 0.33 kg N-N2O ha-1 yr-1 (3.52 kg N-N2O ha-1 yr-1 in the wet season and 1.62 kg N-N2O ha-1 yr-1 in the dry season) during our study period, with highly seasonal variations. The mean N2O emission rates were significantly higher during the wet season (68% of the total average) than the dry season (32% of the total average) (P < 0.05). PIP had the highest N2O emission rate at 3.49 ± 0.61 kg N-N2O ha-1 yr-1 (4.74 kg N-N2O ha-1 yr-1 in the wet season and 2.32 kg N-N2O ha-1 yr-1 in the dry season), followed by SMR at 3.03 ± 0.64 kg N-N2O ha-1 yr-1 (4.16 kg N-N2O ha-1 yr-1 in the wet season and 1.97 kg N-N2O ha-1 yr-1 in the dry season), and then PMR at 1.53 ± 0.49 kg N-N2O ha-1 yr-1 (2.21 kg N-N2O ha-1 yr-1 in the wet season and 0.94 kg N-N2O ha-1 yr-1 in the dry season). We observed a significant Gaussian relationship between the N2O fluxes and soil temperature for SMR and PIP but no significant relationship in PMR. There was a significant exponential relationship between the N2O fluxes and water filled pore space (WFPS) in SMR and PIP but not in PMR.

  11. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, X.; Qi, X.; Zheng, M.

    2015-12-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  12. [Characteristics of CO₂ flux in an old growth mixed forest in Tianmu Mountain, Zhejiang, China].

    PubMed

    Niu, Xiao-dong; Jiang, Hong; Zhang, Jin-meng; Fang, Cheng-yuan; Chen, Xiao-feng; Sun, Heng

    2016-01-01

    The old-growth, multiple ages, multispecies natural forest has played an important role in terrestrial ecosystem dynamics model and the global carbon budget. However, carbon fluxes of old forests in subtropical regions are rarely reported in China. In the present study, the CO₂ flux of an old-growth subtropical evergreen and deciduous broad-leaved mixed forest was observed using eddy covariance technique in Tianmu Mountain of Zhejiang Province. Based on the data sets which were observed from July 2013 to June 2014, the variations of net ecosystem exchange (NEE), eco-system respiration (Re), and gross ecosystem exchange (GEE) were analyzed. The results showed that during the study period, the monthly NEE all had a negative value (acted as a carbon sink) except for December and February (acted as a carbon source). The average monthly NEE was -61.52 g C · m⁻², the monthly carbon sequestration showed a double-peak curve and the maximum carbon sink was -149.40 g C · m⁻², which occurred in June while the maximum carbon source was 23.45 g C · m⁻², which occurred in February. The maximum of monthly mean CO₂ flux occurred in June with a value of -0.98 mg · m⁻² · s⁻¹, while the minimum value occurred in December with a value of -0.35 mg · m⁻² · s⁻¹. The NEE at the time point of positive and negative conversion had typical seasonal characteristics. The yearly NEE, Re, and GEE were -738.18, 931.05 and -1669.23 g C · m⁻², respectively. Compared with other forest ecosystems located at the similar latitude, the carbon fixation of the old-growth forest was larger, likely due to its complicated structure within the canopy and the presence of young-growth regeneration and successional stands. This showed that other than in carbon neutral, old-growth forests of Tianmu Mountain in subtropical China had a strong capability in carbon sequestration.

  13. [Characteristics of CO₂ flux in an old growth mixed forest in Tianmu Mountain, Zhejiang, China].

    PubMed

    Niu, Xiao-dong; Jiang, Hong; Zhang, Jin-meng; Fang, Cheng-yuan; Chen, Xiao-feng; Sun, Heng

    2016-01-01

    The old-growth, multiple ages, multispecies natural forest has played an important role in terrestrial ecosystem dynamics model and the global carbon budget. However, carbon fluxes of old forests in subtropical regions are rarely reported in China. In the present study, the CO₂ flux of an old-growth subtropical evergreen and deciduous broad-leaved mixed forest was observed using eddy covariance technique in Tianmu Mountain of Zhejiang Province. Based on the data sets which were observed from July 2013 to June 2014, the variations of net ecosystem exchange (NEE), eco-system respiration (Re), and gross ecosystem exchange (GEE) were analyzed. The results showed that during the study period, the monthly NEE all had a negative value (acted as a carbon sink) except for December and February (acted as a carbon source). The average monthly NEE was -61.52 g C · m⁻², the monthly carbon sequestration showed a double-peak curve and the maximum carbon sink was -149.40 g C · m⁻², which occurred in June while the maximum carbon source was 23.45 g C · m⁻², which occurred in February. The maximum of monthly mean CO₂ flux occurred in June with a value of -0.98 mg · m⁻² · s⁻¹, while the minimum value occurred in December with a value of -0.35 mg · m⁻² · s⁻¹. The NEE at the time point of positive and negative conversion had typical seasonal characteristics. The yearly NEE, Re, and GEE were -738.18, 931.05 and -1669.23 g C · m⁻², respectively. Compared with other forest ecosystems located at the similar latitude, the carbon fixation of the old-growth forest was larger, likely due to its complicated structure within the canopy and the presence of young-growth regeneration and successional stands. This showed that other than in carbon neutral, old-growth forests of Tianmu Mountain in subtropical China had a strong capability in carbon sequestration. PMID:27228586

  14. [Land use change dynamics and driving forces of the vulnerable ecological region in northwestern Shanxi Province, China].

    PubMed

    Li, Xiu-Fen; Liu, Li-Min; Qi, Xin; Zhang, Jin-Xin; Zhao, Tong-Bin; Wang, Yi; Liu, Xue-Fen; Zhou, Yong-Bin

    2014-10-01

    By using remote sensing and GIS technology, this paper collected land use information of 1980, 1990, 2000 and 2010 and the relevant statistical data, and analyzed the characteristics of land use change and its driving forces in northwestern Shanxi Province, the typical ecological fragile area. The results showed that there were significant changes in land use patterns in the past 30 years. During 1980-1990, 1990-2000 and 2000-2010 periods, the area of farmland decreased continuously, while the areas of grassland and woodland experienced increase-decrease-increase and decrease-increase-decrease patterns of change, respectively. The areas of industrial and resident lands increased continuously, but the water body and unused land decreased. The farmland was mainly transformed to grassland and woodland, and the areas of industrial and resident lands increased from the farmland. The lost area of water body was transformed to grassland and farmland. The decrease of unused land was due to the implementation of ecological engineering and urban ex-panding. In general, the changes of land use types were significantly higher before 2000 than after 2000. The industrial and resident lands, unused land and grassland changed drastically. The relationships between land use types and driving forces indicated that population pressure and economic development led to the changes of industrial land and farmland; policy of forestry ecological engi- neering drove the changes of woodland and grassland; the drought-characterized climate was the major cause inducing the decrease of water area and hindering the restoration of forest.

  15. Social vulnerability of rural households to flood hazards in western mountainous regions of Henan province, China

    NASA Astrophysics Data System (ADS)

    Liu, D. L.; Li, Y.

    2015-11-01

    Evaluating social vulnerability is a crucial issue in risk and disaster management. In this study, a household social vulnerability index (HSVI) to flood hazards was developed and used to assess the social vulnerability of rural households in western mountainous regions of Henan province, China. Eight key indicators were indentified through interactive discussions with multidisciplinary specialists and local farmers, and their weights were determined using principle component analysis (PCA). The results showed that (1) the ratio of perennial working in other places, hazard-related training and illiteracy ratio (15+) were the most dominant factors to social vulnerability. (2) The numbers of high, moderate and low vulnerable households were 14, 64 and 16, respectively, which accounted for 14.9, 68.1, and 17.0 % of the total interviewed rural households, respectively. (3) The correlation coefficient between household social vulnerability scores and casualties in a storm flood in July 2010 was significant at 0.05 significance level (r = 0.248), which indicated that the selected indicators and their weights were valid. (4) Some mitigation strategies to reduce the household social vulnerability to flood hazards were proposed based on the assessment results. The results provide useful information for rural households and local governments to prepare, mitigate and response to flood hazards.

  16. Delayed Flowering in Bamboo: Evidence from Fargesia qinlingensis in the Qinling Mountains of China.

    PubMed

    Wang, Wei; Franklin, Scott B; Lu, Zhijun; Rude, Brian J

    2016-01-01

    Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003-2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the 5 years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction. PMID:26909094

  17. Domain structures in rutile in ultrahigh-pressure metamorphic rocks from Dabie Mountains, China.

    PubMed

    Meng, D W; Wu, X L; Meng, X; Han, Y J; Li, D X

    2004-01-01

    According to the HRTEM study, the UHP jadeite-quartzite mineral (Rutile, TiO(2)) in Anhui Province, Dabie Mountains, China, has ultrastructures such as 011 two-dimensional commensurable modulated structures or superstructures, [011] twin domain structures, dislocations and crystal deformations. The SAED patterns and HRTEM images indicate the existence of the deformations and stacking faults on the interface of [011] twin crystal of rutile and its two-dimensional commensurate modulated structures with repetition period 0.753 nm (3d(011)) has tetragonal symmetry, cell parameters a = 3a0 = 1.377 nm (a0 = 0.459 nm), c = c0 = 0.3 nm. The modulated structures of rutile were probably caused by the isomorphic replacement of Ti(4+) and position modulation or occupation modulation of oxygen atoms in different degree; the deformation structures reveal that during the process of crystallization and mineralization, this mineral may be affected by the geological environment (such as temperature, pressure and stress), metamorphism and deformation.

  18. Delayed Flowering in Bamboo: Evidence from Fargesia qinlingensis in the Qinling Mountains of China

    PubMed Central

    Wang, Wei; Franklin, Scott B.; Lu, Zhijun; Rude, Brian J.

    2016-01-01

    Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003–2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the 5 years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction. PMID:26909094

  19. Raman microscopy of hand stencils rock art from the Yabrai Mountain, Inner Mongolia Autonomous Region, China

    NASA Astrophysics Data System (ADS)

    Hernanz, Antonio; Chang, Jinlong; Iriarte, Mercedes; Gavira-Vallejo, Jose M.; de Balbín-Behrmann, Rodrigo; Bueno-Ramírez, Primitiva; Maroto-Valiente, Angel

    2016-07-01

    A series of rock art pictographs in the form of hand stencils discovered in two sites of the Yabrai Mountain, Inner Mongolia Autonomous Region (China) has been studied by micro-Raman spectroscopy, X-ray photoelectron spectroscopy and scanning electronic microscopy combined with energy dispersive X-ray spectroscopy for the first time. These studies have made possible to characterise the materials present. The minerals α-quartz, phlogopite, albite and microcline have been identified in the granitic rocks supporting the paintings. Calcite and dolomite micro-particles detected on the rock surface have been attributed to desert dust. Accretions of gypsum, anhydrite and whewellite have also been identified on the rock surface. Haematite is the pigment used in the red pictographs, whereas well-crystallised graphite has been used in the black ones. The use of crystalline graphite instead of amorphous carbon (charcoal, soot or bone black) as a black pigment in rock art is an interesting novelty. Overlapped hands are proposed as a new type of hand stencils to make an unusual pictorial symbol in rock art that has been found in these sites.

  20. Natural Regeneration of Trees in Three Types of Afforested Stands in the Taihang Mountains, China

    PubMed Central

    Yang, Xitian; Yan, Dongfeng; Liu, Canran

    2014-01-01

    Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust), Quercus variabilis (Chinese cork oak) and Platycladus orientalis (Chinese arborvitae) respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration. PMID:25268793

  1. Dynamics and anthropogenic impacts of multiple karst flow systems in a mountainous area of South China

    NASA Astrophysics Data System (ADS)

    Luo, Mingming; Chen, Zhihua; Criss, Robert E.; Zhou, Hong; Huang, He; Han, Zhaofeng; Shi, Tingting

    2016-08-01

    The Xiangxi River basin, South China, is a steep terrane with well-developed karst features and an important Cambrian-Ordovician aquifer. Meteoric water in this mountainous area features a mean δ18O elevation gradient of -2.4 ‰/km. This gradient was used to estimate mean recharge elevations of 760 m for Shuimoxi (SMX) spring, 1,060 m for Xiangshuidong (XSD) spring, and 1,430 m for drill hole ZK03, indicating multiple flow paths in the Cambrian-Ordovician karst aquifer. Mean residence times of 230 and 320 days and ˜2 years were estimated for these features, respectively, using the damped running average model that predicts the isotopic variations in groundwater from those in precipitation. Groundwater in the regional karst flow system has the longest residence time, the highest recharge elevation, the longest flow paths, the lowest addition of anthropogenic components, and the greatest amount of water-rock interaction as indicated by its higher dissolved solids, Mg2+ concentrations and Mg/Ca ratios than the springs. In contrast, the local and shallow karst flow systems respond rapidly to recharge events. Artificial tracer tests prove that these shallow karst systems can also quickly transmit anthropogenic contaminants, indicating that they are highly vulnerable to human impacts, which include the enrichment of NO3 -. The intensity of water-rock interaction and groundwater vulnerability are mainly determined by the structure and dynamics of the multiple karst flow systems.

  2. Natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China.

    PubMed

    Yang, Xitian; Yan, Dongfeng; Liu, Canran

    2014-01-01

    Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust), Quercus variabilis (Chinese cork oak) and Platycladus orientalis (Chinese arborvitae) respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration.

  3. Natural radioactivity measurements in rock samples of Cuihua Mountain National Geological Park, China.

    PubMed

    Lu, Xinwei; Zhang, Xiaolan

    2008-01-01

    The concentrations of the natural radionuclides namely 40K, 232Th and 226Ra in rock samples collected from Cuihua Mountain National Geological Park of China have been determined using a NaI(Tl) detector. The concentrations of 226Ra, 232Th and 40K in the studied rock samples range from 10.7 to 34.8, 19.9 to 53.6 and 642.7 to 1609.9 Bq kg(-1) with an average of 20.4, 30.1 and 1009.5 Bq kg(-1), respectively. The concentrations of these radionuclides are compared with the typical world values. To evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, the representative level index and the values of both external and internal hazard indices were evaluated and compared with the internationally approved values. The radium equivalent activity values of all rock samples are lower than the limit of 370 Bq kg(-1). The values of H ex and H in are less than unity. The mean outdoor air absorbed dose rate is 69.7 nGy h(-1), and the corresponding outdoor effective dose rate is 0.086 mSv y(-1).

  4. The efficacy of landscape-level conservation in Changbai Mountain Biosphere Reserve, China.

    PubMed

    Zhang, Jianliang; Liu, Fangzheng; Cui, Guofa

    2014-01-01

    Anthropogenic landscape alteration is rather common in many protected areas (PAs), jeopardizing the efficacy of PAs conservation. However, the general consensus is that PAs still remain effective in habitat conservation. To assess the efficacy of landscape-level conservation, we examined landscape alterations in the Changbai Mountain Biosphere Reserve (CMBR), which was established in 1960 as a "flagship" protected area in China. Based on analyses of high-resolution satellite images and data of forest inventory, field survey and interview, we developed two new indexes to assess the efficacy of landscape conservation, i.e. the quality index of protected landscape and the interference index of anthropogenic landscape. From 1993 to 2012, the quality index increased from 74.48 to 75.50, and the interference index decreased from 0.49 to 0.06, suggesting that the overall quality of protected landscape improved and the degree of anthropogenic interference decreased in CMBR. The increase in landscape quality was mainly due to the progressive vegetation recovery of previous cutover land in the windthrow area, the cease of the use of the cultivated land, and the amelioration of spatial pattern of protected landscape. We conclude that the current landscape conservation methods used in CMBR are effective, and the method we developed has the potential to be used to assess the efficacy of landscape-level conservation in nature reserves worldwide. PMID:24743693

  5. [Canopy interception characteristics of main vegetation types in Liupan Mountains of China].

    PubMed

    Xu, Li-hong; Shi, Zhong-jie; Wang, Yan-hui; Xiong, Wei; Yu, Peng-tao

    2010-10-01

    Based on field observation and modeling analysis, this paper studied the canopy interception, interception capacity, and some parameters for interception modeling of main forest types in Liupan Mountains of China. For the test main forest types, the ratio of their canopy interception to precipitation ranged from 8.59% to 17.94%, throughfall was more than 80%, and stemflow ranged from 0.23% to 3.10%. The canopy interception capacity was 0.78-1.88 mm, among which, leaf interception capacity was 0.62-1.63 mm, and stem interception capacity was 0.13-0.29 mm. Conifer forest had a higher canopy interception capacity than broad-leaved forest. The modified model considering the change of leaf area index, which was used in this paper, had a higher simulating precision than the interception model used before. The simulation results for Betula albo-sinensis forest, Pinus armandii forest, Prunus shrub, and Quercus liaotungensis-Tilia paucicostata forest were good, but those for Quercus liaotungensis forest, Pinus tabulaeformis forest, and Acer tetramerum and Euonymus sanguineus shrub were bad, which might be related to the differences in canopy structure, leaf area index, and precipitation characteristics.

  6. Species diversity of corticolous myxomycetes in Tianmu Mountain National Nature Reserve, China.

    PubMed

    Liu, Qi-Sha; Yan, Shu-Zhen; Dai, Jun-Yong; Chen, Shuang-Lin

    2013-12-01

    The species diversity of corticolous myxomycetes on 4 vegetation types in the Tianmu Mountain National Natural Reserve, eastern China, was examined from 2011 to 2012. A total of 1440 moist chamber cultures were prepared with bark samples, which yielded several hundred collections representing 42 species in 20 genera. It was found that 79% of cultures produced some evidence (either plasmodia or fruiting bodies) of myxomycetes. Eight species (Comatricha elegans, Cribraria confusa, Licea pusilla, Cribraria microcarpa, Collaria arcyrionema, Licea biforis, Arcyria cinerea, and Clastoderma debaryanum) were abundant (exceeding 3% of all records), but about a third of all species were classified as rare. Species richness (S = 33) and diversity (exp[H'] = 16.60, S/G = 1.74) of corticolous myxomycetes were the most diverse in the deciduous broadleaf forest. The species recorded from coniferous forest showed the lowest species richness (S = 21) but the highest evenness (J' = 0.91). The cluster analyses were based on the Bray-Curtis similarity matrix, and the results indicated that corticolous myxomycete assemblages were distributed by a seasonal and annual pattern. Canonical correspondence analysis showed that season and pH were key factors in determining species distribution.

  7. Habitat assessment for giant pandas in the Qinling Mountain region of China

    USGS Publications Warehouse

    Feng, Tian-Tian; Van Manen, Frank T.; Zhao, Na-Xun; Li, Ming; Wei, Fu-Wen

    2009-01-01

    Because habitat loss and fragmentation threaten giant pandas (Ailuropoda melanoleuca), habitat protection and restoration are important conservation measures for this endangered species. However, distribution and value of potential habitat to giant pandas on a regional scale are not fully known. Therefore, we identified and ranked giant panda habitat in Foping Nature Reserve, Guanyinshan Nature Reserve, and adjacent areas in the Qinling Mountains of China. We used Mahalanobis distance and 11 digital habitat layers to develop a multivariate habitat signature associated with 247 surveyed giant panda locations, which we then applied to the study region. We identified approximately 128 km2 of giant panda habitat in Foping Nature Reserve (43.6% of the reserve) and 49 km2 in Guanyinshan Nature Reserve (33.6% of the reserve). We defined core habitat areas by incorporating a minimum patch-size criterion (5.5 km2) based on home-range size. Percentage of core habitat area was higher in Foping Nature Reserve (41.8% of the reserve) than Guanyinshan Nature Reserve (26.3% of the reserve). Within the larger analysis region, Foping Nature Reserve contained 32.7% of all core habitat areas we identified, indicating regional importance of the reserve. We observed a negative relationship between distribution of core areas and presence of roads and small villages. Protection of giant panda habitat at lower elevations and improvement of habitat linkages among core habitat areas are important in a regional approach to giant panda conservation.

  8. Climate-change impacts on understorey bamboo species and giant pandas in China's Qinling Mountains

    NASA Astrophysics Data System (ADS)

    Tuanmu, Mao-Ning; Viña, Andrés; Winkler, Julie A.; Li, Yu; Xu, Weihua; Ouyang, Zhiyun; Liu, Jianguo

    2013-03-01

    Climate change is threatening global ecosystems through its impact on the survival of individual species and their ecological functions. Despite the important role of understorey plants in forest ecosystems, climate impact assessments on understorey plants and their role in supporting wildlife habitat are scarce in the literature. Here we assess climate-change impacts on understorey bamboo species with an emphasis on their ecological function as a food resource for endangered giant pandas (Ailuropoda melanoleuca). An ensemble of bamboo distribution projections associated with multiple climate-change projections and bamboo dispersal scenarios indicates a substantial reduction in the distributional ranges of three dominant bamboo species in the Qinling Mountains, China during the twenty-first century. As these three species comprise almost the entire diet of the panda population in the region, the projected changes in bamboo distribution suggest a potential shortage of food for this population, unless alternative food sources become available. Although the projections were developed under unavoidable simplifying assumptions and uncertainties, they indicate potential challenges for panda conservation and underscore the importance of incorporating interspecific interactions into climate-change impact assessments and associated conservation planning.

  9. Molecular identification of Theileria parasites of northwestern Chinese Cervidae

    PubMed Central

    2014-01-01

    Background Theileria and Babesia protozoan parasites are transmitted mainly by tick vectors. These parasites cause heavy economic losses to the live-stock industry, as well as affecting the health of wild animals in parasite-endemic areas. Identification of infectious agents in wild animals is not only crucial for species preservation, but also provides valuable information on parasite epidemiology. Here, we conducted a molecular surveillance study in Northwestern China to assess the prevalence of blood pathogens in cervids. Methods PCR analysis and microscopic evaluation of blood smears to detect Theileria- and Babesia-related diseases in Cervidae were conducted, in which 22 blood samples from red deer (n = 22) in Qilian Mountain and 20 from sika deer (n = 20) in Long Mountain were collected and tested for the presence of Theileria and Babesia. The 18S rRNA gene was amplified, and selected polymerase chain reaction (PCR)-positive samples were sequenced for species identification. Results PCR revealed that 9.1% of the Qilian Mountain samples and 20% of the Long Mountain samples were positive for Theileria uilenbergi; 90.09% of the Qilian Mountain samples (n = 22) were positive for T. capreoli, but all of the Long Mountain samples (n = 20) were negative for T. capreoli; no other Theileria or Babesia species were found. PCR showed that T. uilenbergi and T. capreoli were present in red deer in Qilian Mountain, while only T. uilenbergi was found in sika Deer in Long Mountain. The 18S rRNA gene sequences were aligned against the corresponding GenBank sequences of known isolates of Theileria and Babesia and subjected to phylogenetic analysis. The phylogenetic tree showed that the newly isolated Theileria spp. could be classified as belonging to two clades: one group belonged to the same clade as T. uilenbergi, the other to a clade containing T. capreoli. Conclusions Our results provide important data to increase understanding of the epidemiology of

  10. Physiological regulation of Syntrichia caninervis Mitt. in different microhabitats during periods of snow in the Gurbantünggüt Desert, northwestern China.

    PubMed

    Yin, Ben-Feng; Zhang, Yuan-Ming

    2016-05-01

    Moss crusts, the most advanced stage of biological soil crust (BSC) development, play important roles in BSC biomass and soil surface stabilization. They usually survive freeze-thaw cycles and remain active during periods of extremely low temperatures. We selected Syntrichia caninervis Mitt., the dominant moss crust species, to study physiological characteristics in winter in three different microhabitats (under the canopy of living shrubs, under dead shrubs, and in exposed areas) in the Gurbantünggüt Desert of northwestern China. The results show that soluble sugar content and antioxidant enzyme activity were significantly higher when heavy snow covered the ground in midwinter, than in early winter and late winter. Soluble protein content was highest in mosses in BSCs under shrub canopies. In contrast, antioxidant enzyme activity was at its maximum in BSCs of exposed areas. Our results indicate that moss crusts have the potential to effectively survive rapid environmental change during winter by an increase in osmoregulatory substances and by increased antioxidant enzymes activity. Mosses in BSCs in exposed areas showed the highest antioxidant enzyme activity, in direct contrast to that of mosses in BSCs growing under canopies of both dead and living shrubs. This may indicate that plants of S. caninervis growing in exposed conditions are better adapted to harsh environmental conditions than plants growing in more sheltered habitats. PMID:26948275

  11. Simultaneously assimilating multivariate data sets into the two-source evapotranspiration model by Bayesian approach: application to spring maize in an arid region of northwestern China

    NASA Astrophysics Data System (ADS)

    Zhu, G. F.; Li, X.; Su, Y. H.; Zhang, K.; Bai, Y.; Ma, J. Z.; Li, C. B.; Hu, X. L.; He, J. H.

    2014-07-01

    Based on direct measurements of half-hourly canopy evapotranspiration (ET; W m-2) using the eddy covariance (EC) system and daily soil evaporation (E; mm day-1) using microlysimeters over a crop ecosystem in arid northwestern China from 27 May to 14 September in 2013, a Bayesian method was used to simultaneously parameterize the soil surface and canopy resistances in the Shuttleworth-Wallace (S-W) model. Four of the six parameters showed relatively larger uncertainty reductions (> 50%), and their posterior distributions became approximately symmetric with distinctive modes. There was a moderately good agreement between measured and simulated values of half-hourly ET and daily E with a linear regression being y = 0.84 x + 0.18 (R2 = 0.83) and y = 1.01 x + 0.01 (R2 = 0.82), respectively. The causes of underestimations of ET by the S-W model was possibly attributed to the microscale advection, which can contribute an added energy in the form of downward sensible heat fluxes to the ET process. Therefore, the advection process should be taken into account in simulating ET in heterogeneous land surfaces. Also, underestimations were observed on or shortly after rainy days, which may be due to direct evaporation of liquid water intercepted in the canopy. Thus, the canopy interception model should be coupled to the S-W model in the long-term ET simulation.

  12. The effects of a dry sand layer on groundwater recharge in extremely arid areas: field study in the western Hexi Corridor of northwestern China

    NASA Astrophysics Data System (ADS)

    Sun, Peng; Ma, Jinzhu; Qi, Shi; Zhao, Wei; Zhu, Gaofeng

    2016-04-01

    Evaporation capacity is an important factor that cannot be ignored when judging whether extreme precipitation events will produce groundwater recharge. The evaporation layer's role in groundwater recharge was evaluated using a lysimeter simulation experiment in the desert area of Dunhuang, in the western part of the Hexi Corridor in northwestern China's Gansu Province. The annual precipitation in the study area is extremely low, averaging 38.87 mm during the 60-year study period, and daily pan evaporation amounts to 2,486 mm. Three simulated precipitation regimes (normal, 10 mm; ordinary annual maximum, 21 mm; and extreme, 31 mm) were used in the lysimeter simulation to allow monitoring of water movement and weighing to detect evaporative losses. The differences in soil-water content to a depth of 50 cm in the soil profile significantly affected rainfall infiltration during the initial stages of rainfall events. It was found that the presence of a dry 50-cm-deep sand layer was the key factor for "potential recharge" after the three rainfall events. Daily precipitation events less than 20 mm did not produce groundwater recharge because of the barrier effect created by the dry sand. Infiltration totaled 0.68 mm and penetrated to a depth below 50 cm with 31 mm of rainfall, representing potential recharge equivalent to 1.7 % of the rainfall. This suggests that only extreme precipitation events offer the possibility of recharge of groundwater in this extremely arid area.

  13. Detecting the sensitivity of magnetic response on different pollution sources--A case study from typical mining cities in northwestern China.

    PubMed

    Wang, Bo; Xia, Dunsheng; Yu, Ye; Jia, Jia; Nie, Yan; Wang, Xin

    2015-12-01

    Rapid monitoring and discriminating different anthropogenic pollution is a key scientific issue. To detect the applicability and sensitivity of magnetic measurements for evaluating different industrial pollution in urban environment, characteristics of topsoil from three typical fast developing industrial cities (Jinchang, Baiyin and Jiayuguan in Gansu province, northwestern China) were studied by magnetic and geochemical analyses. The results showed that magnetic susceptibility was enhanced near industrial areas, and PSD-MD magnetite dominated the magnetic properties. Magnetic concentration parameters (χlf, SIRM, and χARM) showed different correlations with heavy metals and PLI in the three cities, indicating significantly different magnetic response to different pollution sources. Principal component analysis showed that ferrimagnetic minerals coexist with heavy metals of Fe, As, Cu, Pb, and Zn in Baiyin and Fe, V, Cu, Mn, Pb, and Cr in Jiayuguan. Fuzzy cluster analysis and regression analysis further indicated that the sensitivity of magnetic monitoring to fuel dust is higher than that to mineral dust near non-ferrous metal smelters, and fossil fuel consumption is an important factor for increasing magnetite content. In all the three cities, the sensitivity of magnetic monitoring to pollutants from steel plants is much higher than that from non-ferrous metal plants. Therefore, magnetic proxies provide a rapid means for detecting heavy metal contamination caused by multi-anthropogenic pollution sources in a large scale area, however, the sensitivity was controlled by pollution sources. PMID:26412269

  14. Predicting available water of soil from particle-size distribution and bulk density in an oasis-desert transect in northwestern China

    NASA Astrophysics Data System (ADS)

    Li, Danfeng; Gao, Guangyao; Shao, Ming'an; Fu, Bojie

    2016-07-01

    A detailed understanding of soil hydraulic properties, particularly the available water content of soil, (AW, cm3 cm-3), is required for optimal water management. Direct measurement of soil hydraulic properties is impractical for large scale application, but routinely available soil particle-size distribution (PSD) and bulk density can be used as proxies to develop various prediction functions. In this study, we compared the performance of the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Arya and Heitman (AH) model, and Rosetta program in predicting the soil water characteristic curve (SWCC) at 34 points with experimental SWCC data in an oasis-desert transect (20 × 5 km) in the middle reaches of the Heihe River basin, northwestern China. The idea of the three models emerges from the similarity of the shapes of the PSD and SWCC. The AP model, MV model, and Rosetta program performed better in predicting the SWCC than the AH model. The AW determined from the SWCCs predicted by the MV model agreed better with the experimental values than those derived from the AP model and Rosetta program. The fine-textured soils were characterized by higher AW values, while the sandy soils had lower AW values. The MV model has the advantages of having robust physical basis, being independent of database-related parameters, and involving subclasses of texture data. These features make it promising in predicting soil water retention at regional scales, serving for the application of hydrological models and the optimization of soil water management.

  15. Diversity and structure of a bacterial community in grassland soils disturbed by sheep grazing, in the Loess Plateau of northwestern China.

    PubMed

    Gou, Y N; Nan, Z B; Hou, F J

    2015-12-15

    The relationship between disturbance, biodiversity, and ecosystem function has been a hot topic recently in international ecological research, and a universally applicable model remains elusive. In this study, we assessed the diversity and structure of a bacterial community in grassland soils along a disturbance gradient due to sheep grazing. Bacteria were identified based on 16S rDNA gene libraries prepared from a 12-year field experiment that included four grazing, intensity treatments: no grazing, light grazing, moderate grazing and heavy grazing in the Loess Plateau of northwestern China. We found that diversity indices of bacterial 16S rDNA increased with grazing intensity, suggesting that disturbance led to higher bacterial diversity. The bacterial community structure, measured as species composition, was also affected by grazing. In addition, the change in soil bacterial community composition was maximum under heavy grazing, based on the Sorensen similarity index. Overall, the relationship between disturbance and bacterial diversity is complex, therefore, more studies are required to determine the possibility of using microbial diversity as an indicator of ecosystem stability.

  16. Detecting the sensitivity of magnetic response on different pollution sources--A case study from typical mining cities in northwestern China.

    PubMed

    Wang, Bo; Xia, Dunsheng; Yu, Ye; Jia, Jia; Nie, Yan; Wang, Xin

    2015-12-01

    Rapid monitoring and discriminating different anthropogenic pollution is a key scientific issue. To detect the applicability and sensitivity of magnetic measurements for evaluating different industrial pollution in urban environment, characteristics of topsoil from three typical fast developing industrial cities (Jinchang, Baiyin and Jiayuguan in Gansu province, northwestern China) were studied by magnetic and geochemical analyses. The results showed that magnetic susceptibility was enhanced near industrial areas, and PSD-MD magnetite dominated the magnetic properties. Magnetic concentration parameters (χlf, SIRM, and χARM) showed different correlations with heavy metals and PLI in the three cities, indicating significantly different magnetic response to different pollution sources. Principal component analysis showed that ferrimagnetic minerals coexist with heavy metals of Fe, As, Cu, Pb, and Zn in Baiyin and Fe, V, Cu, Mn, Pb, and Cr in Jiayuguan. Fuzzy cluster analysis and regression analysis further indicated that the sensitivity of magnetic monitoring to fuel dust is higher than that to mineral dust near non-ferrous metal smelters, and fossil fuel consumption is an important factor for increasing magnetite content. In all the three cities, the sensitivity of magnetic monitoring to pollutants from steel plants is much higher than that from non-ferrous metal plants. Therefore, magnetic proxies provide a rapid means for detecting heavy metal contamination caused by multi-anthropogenic pollution sources in a large scale area, however, the sensitivity was controlled by pollution sources.

  17. The effects of a dry sand layer on groundwater recharge in extremely arid areas: field study in the western Hexi Corridor of northwestern China

    NASA Astrophysics Data System (ADS)

    Sun, Peng; Ma, Jinzhu; Qi, Shi; Zhao, Wei; Zhu, Gaofeng

    2016-09-01

    Evaporation capacity is an important factor that cannot be ignored when judging whether extreme precipitation events will produce groundwater recharge. The evaporation layer's role in groundwater recharge was evaluated using a lysimeter simulation experiment in the desert area of Dunhuang, in the western part of the Hexi Corridor in northwestern China's Gansu Province. The annual precipitation in the study area is extremely low, averaging 38.87 mm during the 60-year study period, and daily pan evaporation amounts to 2,486 mm. Three simulated precipitation regimes (normal, 10 mm; ordinary annual maximum, 21 mm; and extreme, 31 mm) were used in the lysimeter simulation to allow monitoring of water movement and weighing to detect evaporative losses. The differences in soil-water content to a depth of 50 cm in the soil profile significantly affected rainfall infiltration during the initial stages of rainfall events. It was found that the presence of a dry 50-cm-deep sand layer was the key factor for "potential recharge" after the three rainfall events. Daily precipitation events less than 20 mm did not produce groundwater recharge because of the barrier effect created by the dry sand. Infiltration totaled 0.68 mm and penetrated to a depth below 50 cm with 31 mm of rainfall, representing potential recharge equivalent to 1.7 % of the rainfall. This suggests that only extreme precipitation events offer the possibility of recharge of groundwater in this extremely arid area.

  18. Combination of magnetic parameters and heavy metals to discriminate soil-contamination sources in Yinchuan--a typical oasis city of Northwestern China.

    PubMed

    Xia, Dunsheng; Wang, Bo; Yu, Ye; Jia, Jia; Nie, Yan; Wang, Xin; Xu, Shujing

    2014-07-01

    Various industrial processes and vehicular traffic result in harmful emissions containing both magnetic minerals and heavy metals. In this study, we investigated the levels of magnetic and heavy metal contamination of topsoils from Yinchuan city in northwestern China. The results demonstrate that magnetic mineral assemblages in the topsoil are dominated by pseudo-single domain (PSD) and multi-domain (MD) magnetite. The concentrations of anthropogenic heavy metals (Cr, Cu, Pb and Zn) and the magnetic properties of χlf, SIRM, χARM, and 'SOFT' and 'HARD' remanence are significantly correlated, suggesting that the magnetic minerals and heavy metals have common sources. Combined use of principal components and fuzzy cluster analysis of the magnetic and chemical data set indicates that the magnetic and geochemical properties of the particulates emitted from different sources vary significantly. Samples from university campus and residential areas are mainly affected by crustal material, with low concentrations of magnetic minerals and heavy metals, while industrial pollution sources are characterized by high concentrations of coarse magnetite and Cr, Cu, Pb and Zn. Traffic pollution is characterized by Pb and Zn, and magnetite. Magnetic measurements of soils are capable of differentiating sources of magnetic minerals and heavy metals from industrial processes, vehicle fleets and soil parent material.

  19. Detection and differentiation of pollution in urban surface soils using magnetic properties in arid and semi-arid regions of northwestern China.

    PubMed

    Wang, Bo; Xia, Dunsheng; Yu, Ye; Jia, Jia; Xu, Shujing

    2014-01-01

    Increasing urbanization and industrialization over the world has caused many social and environmental problems, one of which drawing particular concern is the soil pollution and its ecological degradation. In this study, the efficiency of magnetic methods for detecting and discriminating contaminates in the arid and semi-arid regions of northwestern China was investigated. Topsoil samples from six typical cities (i.e. Karamay, Urumqi, Lanzhou, Yinchuan, Shizuishan and Wuhai) were collected and a systematic analysis of their magnetic properties was conducted. Results indicate that the topsoil samples from the six cities were all dominated by coarse low-coercivity magnetite. In addition, the average magnetite contents in the soils from Urumqi and Lanzhou were shown to be much higher than those from Karamay, Yinchuan, Shizuishan and Wuhai, and they also have relatively higher χlf and χfd% when compared with cities in eastern China. Moreover, specific and distinctive soil pollution signals were identified at each sampling site using the combined various magnetic data, reflecting distinct sources. Industrial and traffic-derived pollution was dominant in Urumqi and Lanzhou, in Yinchuan industrial progress was observed to be important with some places affected by vehicle emission, while Karamay, Shizuishan and Wuhai were relatively clean. The magnetic properties of these latter three cities are significantly affected by both anthropogenic pollution and local parent materials from the nearby Gobi desert. The differences in magnetic properties of topsoil samples affected by mixed industrial and simplex traffic emissions are not obvious, but significant differences exist in samples affected by simplex industrial/vehicle emissions and domestic pollution. The combined magnetic analyses thus provide a sensitive and powerful tool for classifying samples according to likely sources, and may even provide a valuable diagnostic tool for discriminating among different cities.

  20. Prediction of hidden Au and Cu-Ni ores from depleted mines in Northwestern China: four case studies of integrated geological and geophysical investigations

    NASA Astrophysics Data System (ADS)

    Shen, Ping; Shen, Yuanchao; Liu, Tiebing; Li, Guangming; Zeng, Qingdong

    2008-07-01

    Integrated geological and geophysical investigations were carried out in 26 active mines in Northwestern China during the period 2001-2006 to explore for hidden extensions of known ore bodies and to search for new mineralization. This paper presents four case studies from northwest China: the Kuoerzhenkuoa volcanogenic hydrothermal gold deposit, the Nanjinshan breccia-associated gold deposit, the Duolanasayi deposit, associated with a ductile-shear zone, and the Hulu magmatic Cu-Ni sulfide deposit. In these studies, detailed mine-scale geological studies were carried out to determine the location and controls on ore formation. Based on these investigations and a review of previous exploration data, genetic models for the deposits were evaluated, and specific new targets were generated. These target areas were tested with surface geophysical surveys using the Stratagem EH4 system, a hybrid-source magnetotellurics (MT) method. Analysis of the data obtained in the surveys identified geophysical target anomalies that were subsequently drilled. Many of these test holes demonstrate the presence of Au and Cu-Ni mineralization. Evaluation of the geological models was crucial in developing conceptual targets as a basis for surface geophysical surveys. These models established the most likely target areas where Au and Cu-Ni mineralization could occur, but they did not define the limits or the geometries of the mineralized zones. Hybrid MT surveys played an important role in defining the location of buried mineralized systems and in testing the validity of the conceptual targets. The resistivity cross-sections obtained by imaging the MT data established the boundaries and geometries of the host rocks, including the distribution of lithology, structures, alteration, and mineralization. The four case studies in this paper show how this integrated geological and geophysical approach was used successfully to discover hidden mineral deposits.

  1. Identification of Phytophthora species baited and isolated from forest soil and streams in northwestern Yunnan province, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora species were surveyed by collecting soil samples and placing bait leaves in selected streams during June - October in the years 2005, 2006 and 2010 at three sites in oak forests in Diqing Tibetan Autonomous Prefecture of NW Yunnan province, China. Seventy-three isolates of Phytophthora ...

  2. Interglacial refugia preserved high genetic diversity of the Chinese mole shrew in the mountains of southwest China.

    PubMed

    He, K; Hu, N-Q; Chen, X; Li, J-T; Jiang, X-L

    2016-01-01

    The mountains of southwest China (MSC) harbor extremely high species diversity; however, the mechanism behind this diversity is unknown. We investigated to what degree the topography and climate change shaped the genetic diversity and diversification in these mountains, and we also sought to identify the locations of microrefugia areas in these mountains. For these purposes, we sampled extensively to estimate the intraspecific phylogenetic pattern of the Chinese mole shrew (Anourosorex squamipes) in southwest China throughout its range of distribution. Two mitochondrial genes, namely, cytochrome b (CYT B) and NADH dehydrogenase subunit 2 (ND2), from 383 archived specimens from 43 localities were determined for phylogeographic and demographic analyses. We used the continuous-diffusion phylogeographic model, extensive Bayesian skyline plot species distribution modeling (SDM) and approximate Bayesian computation (ABC) to explore the changes in population size and distribution through time of the species. Two phylogenetic clades were identified, and significantly higher genetic diversity was preserved in the southern subregion of the mountains. The results of the SDM, continuous-diffusion phylogeographic model, extensive Bayesian skyline plot and ABC analyses were congruent and supported that the Last Interglacial Maximum (LIG) was an unfavorable period for the mole shrews because of a high degree of seasonality; A. squamipes survived in isolated interglacial refugia mainly located in the southern subregion during the LIG and rapidly expanded during the last glacial period. These results furnished the first evidence for major Pleistocene interglacial refugia and a latitudinal effect in southwest China, and the results shedding light on the higher level of species richness in the southern subregion. PMID:26286667

  3. [Land use change dynamics and driving forces of the vulnerable ecological region in northwestern Shanxi Province, China].

    PubMed

    Li, Xiu-Fen; Liu, Li-Min; Qi, Xin; Zhang, Jin-Xin; Zhao, Tong-Bin; Wang, Yi; Liu, Xue-Fen; Zhou, Yong-Bin

    2014-10-01

    By using remote sensing and GIS technology, this paper collected land use information of 1980, 1990, 2000 and 2010 and the relevant statistical data, and analyzed the characteristics of land use change and its driving forces in northwestern Shanxi Province, the typical ecological fragile area. The results showed that there were significant changes in land use patterns in the past 30 years. During 1980-1990, 1990-2000 and 2000-2010 periods, the area of farmland decreased continuously, while the areas of grassland and woodland experienced increase-decrease-increase and decrease-increase-decrease patterns of change, respectively. The areas of industrial and resident lands increased continuously, but the water body and unused land decreased. The farmland was mainly transformed to grassland and woodland, and the areas of industrial and resident lands increased from the farmland. The lost area of water body was transformed to grassland and farmland. The decrease of unused land was due to the implementation of ecological engineering and urban ex-panding. In general, the changes of land use types were significantly higher before 2000 than after 2000. The industrial and resident lands, unused land and grassland changed drastically. The relationships between land use types and driving forces indicated that population pressure and economic development led to the changes of industrial land and farmland; policy of forestry ecological engi- neering drove the changes of woodland and grassland; the drought-characterized climate was the major cause inducing the decrease of water area and hindering the restoration of forest. PMID:25796906

  4. Mountain Meadows Dacite: Oligocene intrusive complex that welds together the Los Angeles Basin, northwestern Peninsular Ranges, and central Transverse Ranges, California

    USGS Publications Warehouse

    McCulloh, Thane H.; Beyer, Larry A.; Morin, Ronald W.

    2001-01-01

    Dikes and irregular intrusive bodies of distinctive Oligocene biotite dacite and serially related hornblende latite and felsite occur widely in the central and eastern San Gabriel Mountains, southern California, and are related to the Telegraph Peak granodiorite pluton. Identical dacite is locally present beneath Middle Miocene Topanga Group Glendora Volcanics at the northeastern edge of the Los Angeles Basin, where it is termed Mountain Meadows Dacite. This study mapped the western and southwestern limits of the dacite distribution to understand the provenance of derived redeposited clasts, to perceive Neogene offsets on several large strike-slip faults, to test published palinspastic reconstructions, and to better understand the tectonic boundaries that separate contrasting pre-Tertiary rock terranes where the Peninsular Ranges meet the central and western Transverse Ranges and the Los Angeles Basin. Transported and redeposited clasts of dacite-latite occur in deformed lower Miocene and lower middle Miocene sandy conglomerates (nonmarine, nearshore, and infrequent upper bathyal) close to the northern and northeastern margins of the Los Angeles Basin for a distance of nearly 60 km. Tie-lines between distinctive source suites and clast occurrences indicate that large tracts of the ancestral San Gabriel Mountains were elevated along range-bounding faults as early as 16–15 Ma. The tie-lines prohibit very large strike-slip offsets on those faults. Transport of eroded dacite began south of the range as early as 18 Ma. Published and unpublished data about rocks adjacent to the active Santa Monica-Hollywood-Raymond oblique reverse left-lateral fault indicate that cumulative left slip totals 13–14 km and total offset postdates 7 Ma. This cumulative slip, with assembly of stratigraphic and paleogeographic data, invalidates prior estimates of 60 to 90 km of left slip on these faults beginning about 17–16 Ma. A new and different palinspastic reconstruction of a region

  5. Viable contribution of Tibetan sacred mountains in southwestern China to forest conservation.

    PubMed

    Shen, Xiaoli; Li, Sheng; Wang, Dajun; Lu, Zhi

    2015-12-01

    The Tibetan sacred mountains (TSMs) cover a large area and may represent a landscape-scale conservation opportunity. We compared the conservation value of forests in these mountains with the conservation value of government-established nature reserves and unmanaged open-access areas in Danba County, southwestern China. We used Landsat satellite images to map forest cover and to estimate forest loss in 1974-1989, 1989-1999, and 1999-2013. The TSMs (n = 41) and nature reserves (n = 4) accounted for 21.6% and 29.7% of the county's land area, respectively. Remaining land was open-access areas (i.e., areas without any restrictions on resource use) (56.2%) and farmlands (2.2%). Within the elevation range suitable for forests, forest cover did not differ significantly between nature reserves (58.8%) and open-access areas (58.4%), but was significantly higher in TSMs (65.5%) after controlling for environmental factors such as aspect, slope, and elevation. The TSMs of great cultural importance had higher forest cover, but patrols by monastery staff were not necessarily associated with increased forest cover. The annual deforestation rate in nonsacred areas almost tripled in 1989-1999 (111.4 ha/year) relative to 1974-1989 (40.4 ha/year), whereas the rate in TSMs decreased in the later period (19.7 ha/year vs. 17.2 ha/year). The reduced forest loss in TSMs in 1989-1999 was possibly due to the renaissance of TSM worship and strengthened management by the local Buddhist community since late 1980s. The annual deforestation rate in Danba decreased dramatically to 4.4 ha/year in 1999-2013, which coincided with the implementation of a national ban on logging in 1998. As the only form of protected area across the Tibetan region during much of its history, TSMs have positively contributed to conserving forest at a landscape scale. Conservation of TSM forests largely relied on the strength of local religious institutions. Integrating community-based conservation of TSMs within the

  6. Viable contribution of Tibetan sacred mountains in southwestern China to forest conservation.

    PubMed

    Shen, Xiaoli; Li, Sheng; Wang, Dajun; Lu, Zhi

    2015-12-01

    The Tibetan sacred mountains (TSMs) cover a large area and may represent a landscape-scale conservation opportunity. We compared the conservation value of forests in these mountains with the conservation value of government-established nature reserves and unmanaged open-access areas in Danba County, southwestern China. We used Landsat satellite images to map forest cover and to estimate forest loss in 1974-1989, 1989-1999, and 1999-2013. The TSMs (n = 41) and nature reserves (n = 4) accounted for 21.6% and 29.7% of the county's land area, respectively. Remaining land was open-access areas (i.e., areas without any restrictions on resource use) (56.2%) and farmlands (2.2%). Within the elevation range suitable for forests, forest cover did not differ significantly between nature reserves (58.8%) and open-access areas (58.4%), but was significantly higher in TSMs (65.5%) after controlling for environmental factors such as aspect, slope, and elevation. The TSMs of great cultural importance had higher forest cover, but patrols by monastery staff were not necessarily associated with increased forest cover. The annual deforestation rate in nonsacred areas almost tripled in 1989-1999 (111.4 ha/year) relative to 1974-1989 (40.4 ha/year), whereas the rate in TSMs decreased in the later period (19.7 ha/year vs. 17.2 ha/year). The reduced forest loss in TSMs in 1989-1999 was possibly due to the renaissance of TSM worship and strengthened management by the local Buddhist community since late 1980s. The annual deforestation rate in Danba decreased dramatically to 4.4 ha/year in 1999-2013, which coincided with the implementation of a national ban on logging in 1998. As the only form of protected area across the Tibetan region during much of its history, TSMs have positively contributed to conserving forest at a landscape scale. Conservation of TSM forests largely relied on the strength of local religious institutions. Integrating community-based conservation of TSMs within the

  7. Qian'echong low-F porphyry Mo deposits in the Dabie Mountains, central China

    NASA Astrophysics Data System (ADS)

    Mi, Mei; Li, Cong-ying; Sun, Wei-dong

    2015-12-01

    The Qian'echong Mo deposit is a large porphyry Mo deposit located in the northwest Dabie Mountains, central China, with proven Mo reserves of 741 Mt at 0.081%. Chondrite-normalized REE patterns of most zircon from samples QEC002, 003, 004 and 011 show HREE enrichment with distinctive positive Ce and moderately negative Eu anomalies, which are typical of magmatic zircon in porphyry deposits. Zircon grains from sample QEC001 are all hydrothermal in origin, whereas there are only several hydrothermal zircons in the other samples. The Ti-in-zircon thermometer yields temperatures of 700-740 °C for the magmatic zircon. The Ce4 +/Ce3 + calculated from the Ce anomaly is a sensitive and robust indicator of magmatic oxidation status. Magmatic zircon have Ce4 +/Ce3 + and (Eu/Eu*)N ratios ranging between 10-577 and 0.2-1.3, respectively. Compared to the Shapinggou deposit (Climax type) also in the Dabie Mountains, the Qian'echong zircon has systematically lower Ce4 +/Ce3 +. Apatite from the Qian'echong deposit belongs to the F-apatite variety, with fluorine concentrations varying between 2.13-4.50% and Cl concentrations between 0.01-0.28%. Whole rock samples of the porphyry from the Qian'echong deposit have F contents of 360-1230 ppm. The porphyry intrusion is consistently associated with calc-alkaline granitic to granodioritic porphyries, with lower F, Nb, and Ta concentrations, and systematically lower Mo contents than the Climax-type deposits. All these characteristics are similar to other low-F porphyry Mo deposits along the eastern Pacific margin. Fluorine is mainly hosted in phengite during plate subduction, which may decompose far beneath the surface of the subduction zone. Therefore, high F deposits may be interpreted as locating the farthermost position reached by the subducting slab. Nevertheless, the F contents of the Qian'echong deposit is much higher than in adjacent barren granites, and may have incorporated additional F from the subduction slab. Given that the

  8. Proterozoic polymetamorphism in the Quanji Block, northwestern China: Evidence from microtextures, garnet compositions and monazite CHIME ages

    NASA Astrophysics Data System (ADS)

    Wang, Qinyan; Pan, Yuanming; Chen, Nengsong; Li, Xiaoyan; Chen, Haihong

    2009-05-01

    The Quanji Block, situated close to the triple junction of three major Precambrian terranes in China (i.e., the North China Craton, the Yangtze Block and the Tarim Block), is composed of Precambrian metamorphic crystalline basement and an unmetamorphosed Mesozoic-Paleozoic sedimentary cover; it has been interpreted as a remnant continental fragment. Microtextural relationships, garnet trace element compositions, and monazite CHIME ages in paragneisses, schists and granitic leucosomes show two episodes of regional metamorphism in the Quanji Block basement. The first regional metamorphism and accompaning anatexis took place at ˜1.93 Ga; the second regional metamorphism occurred between ˜1.75 and ˜1.71 Ga. Mineral compositions of the first metamorphism, including those of monazite, were significantly disturbed by the second event. These two regional metamorphic episodes were most likely linked to assembly and breakup of the supercontinent Columbia, respectively.

  9. Folded fluvial terraces and the deforming of a new uplifted region in the mountain front the Qilian Shan Mountain, China

    NASA Astrophysics Data System (ADS)

    Hu, X.; Pan, B.; Wang, J.; Hu, Z.

    2014-12-01

    How the Tibetan Plateau is extended is one of the key problems to understand the earth crust evolution in the frame of plate tectonics. A newly uplifting area, the Dahe region, locating between the Yumu Shan Mountain and the Qilian Shan Mountain, in the northeastern Tibetan Plateau, would supply us a fresh sight on the process that how the plateau is extended to a new region. The Dahe region was a relatively depressing or stable area before late Pleistocene, and received thick fluvial sediment derived from the Qilian Shan in the south. In late Pleistocene, the old depositing surface Sp (alluvial fan surface) was deeply cut by the Dahe River. Below the old depositing surface, four staircases of strath terraces (strath is the old fluvial deposition) are formed by the Dahe River, and each terrace surfaces are buried by aeolian loess. By the OSL dating on overlying loess on the terraces and correlating to climate records, we obtain formation ages (terrace surface abandoning time) of the four terraces (from high to low): 128.2 ±9.8 ka, 109.6±20.8 ka, 96.3 ±9.0 ka, and 15.9 ±2.5 ka. We obtain the extrapolated Sp age of 160 ±25 ka, which represents the time when the fan depositing was end and river cutting and eroding was started in the Dahe region. By the uplifted terrace staircases and warped long profiles of terraces, we can find that the region is not only experiencing regional uplifting but also folding deformation. Through analyzing the geometry of the deforming terrace surfaces, we propose that a new blind thrust fault was derived from the main decollement in the upper crust, and thus the growing fault deduced the uplift of the Dahe region and the folding near the fault tip. The growth of the Dahe region, which is sandwiched by the Yumu Shan and the Qilian Shan, both uplifted millions years ago, suggests that northeastern extending of the plateau is in the form of new fault-fold system growing in mountain front and back.

  10. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, Xiaozhi; He, Dengfa; Qi, Xuefeng

    2016-04-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  11. Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

    PubMed

    Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

    2016-01-01

    The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that. PMID:26730966

  12. Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China

    PubMed Central

    Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

    2016-01-01

    The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2–16.6 ka BP and 12.8–11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3–18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that. PMID:26730966

  13. Nonpoint source pollution responses simulation for conversion cropland to forest in mountains by SWAT in China.

    PubMed

    Ouyang, Wei; Hao, Fang-Hua; Wang, Xue-Lei; Cheng, Hong-Guang

    2008-01-01

    Several environmental protection policies have been implemented to prevent soil erosion and nonpoint source (NPS) pollutions in China. After severe Yangtze River floods, the "conversion cropland to forest policy" (CCFP) was carried out throughout China, especially in the middle and upper reaches of Yangtze River. The research area of the current study is located in Bazhong City, Sichuan Province in Yangtze River watershed, where soil erosion and NPS pollution are serious concerns. Major NPS pollutants include nitrogen (N) and phosphorus (P). The objective of this study is to evaluate the long-term impact of implementation of the CCFP on stream flow, sediment yields, and the main NPS pollutant loading at watershed level. The Soil and Water Assessment Tool (SWAT) is a watershed environmental model and is applied here to simulate and quantify the impacts. Four scenarios are constructed representing different patterns of conversion from cropland to forest under various conditions set by the CCFP. Scenario A represented the baseline, i.e., the cropland and forest area conditions before the implementation of CCFP. Scenario B represents the condition under which all hillside cropland with slope larger than 25 degrees was converted into forest. In scenario C and D, hillside cropland with slope larger than 15 degrees and 7.5 degrees was substituted by forest, respectively. Under the various scenarios, the NPS pollution reduction due to CCFP implementation from 1996-2005 is estimated by SWAT. The results are presented as percentage change of water flow, sediment, organic N, and organic P at watershed level. Furthermore, a regression analysis is conducted between forest area ratio and ten years' average NPS load estimations, which confirmed the benefits of implementing CCFP in reducing nonpoint source pollution by increasing forest area in mountainous areas. The reduction of organic N and organic P is significant (decrease 42.1% and 62.7%, respectively) at watershed level. In

  14. Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

    PubMed

    Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

    2016-01-01

    The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

  15. Millennial minimum temperature variations in the Qilian Mountains, China: evidence from tree rings

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Shao, X. M.; Yin, Z.-Y.; Wang, Y.

    2014-09-01

    A 1343-year tree-ring chronology was developed from Qilian junipers in the central Qilian Mountains of the northeastern Tibetan Plateau (TP), China. The climatic implications of this chronology were investigated using simple correlation, partial correlation and response function analyses. The chronology was significantly positively correlated with temperature variables prior to and during the growing season, especially with monthly minimum temperature. Minimum temperature anomalies from January to August since AD 670 were then reconstructed based on the tree-ring chronology. The reconstruction explained 58% of the variance in the instrumental temperature records during the calibration period (1960-2012) and captured the variation patterns in minimum temperature at the annual to centennial timescales over the past millennium. The most recent 50 years were the warmest period, while 1690-1880 was the coldest period since AD 670. Comparisons with other temperature series from neighbouring regions and for the Northern Hemisphere as a whole supported the validity of our reconstruction and suggested that it provided a good regional representation of temperature change in the northeastern Tibetan Plateau. The results of wavelet analysis showed the occurrence of significant quasi-periodic patterns at a number of recurring periods (2-4, 40-50, and 90-170 years), which were consistent with those associated with El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and solar activity. The comparison between the reconstructed temperature and the index of tropical volcanic radiative forcing indicated that some cold events recorded by tree rings may be due to the impact of tropical volcanic eruptions.

  16. Millennial Minimum Temperature Variations in the Qilian Mountains, China: evidence from Tree rings

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Shao, X.; Yin, Z.-Y.; Wang, Y.

    2014-01-01

    A 1342 yr-long tree-ring chronology was developed from Qilian junipers in the central Qilian Mountains of the north-eastern Tibetan Plateau, China. The climatic implications of this chronology were investigated using simple correlation, partial correlation and response function analyses. The chronology was significantly positively correlated with temperature variables during the pre- and current growing seasons, especially with minimum temperature. The variability of the mean minimum temperature from January to August since 670 AD was then reconstructed based on the tree-ring chronology. The reconstruction explained 58.5% of the variance in the instrumental temperature records during the calibration period (1960-2011) and captured the variation patterns in minimum temperature at the annual to centennial time scales over the past millennium. The most recent 50 yr were the warmest period, while 1690-1880 was the coldest period since 670 AD. Comparisons with other temperature series from neighbouring regions and for the Northern Hemisphere as a whole supported the validity of our reconstruction and suggested that it provided a good regional representation of temperature change in the north-eastern Tibetan Plateau. The results of multi-taper spectral analysis showed the occurrence of significant quasi-periodic behaviour at a number of periods (2-3, 28.8-66.2, 113.6-169.5, and 500 yr), which were consistent with those associated with El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and solar activity. Some reconstructed cold events may have close relationship with the volcanic eruptions.

  17. Rapid loss of phosphorus during early pedogenesis along a glacier retreat choronosequence, Gongga Mountain (SW China)

    PubMed Central

    Zhou, Jun; Bing, Haijian; Sun, Hongyang; Wang, Jipeng

    2015-01-01

    The loss of phosphorus (P) during the early pedogenesis stage is important at the ecosystem level, and it also plays an important role in the global P cycle. The seasonal variation of total P (Pt) and its fractions along a young soil chronosequence (Hailuogou chronosequence) on the eastern slope of Gongga Mountain, SW China, was investigated based on the modified Hedley fractionation technique to understand P loss during the early pedogenesis stage. The results showed that the mineral P (mainly apatite) was the dominant fraction of Pt in the C horizon of the soil, and the seasonal difference in Pt and its fractions was insignificant. In the A horizon, Pt concentrations decreased markedly compared with those in the C horizon, and as the age of the soil increased, the inorganic P (Pi) significantly decreased and the organic P (Po) prominently increased. Seasonally, the P fractions exhibited various distributions in the A horizon. The variation of Pt and its fractions revealed that the P loss was rapid along the 120-year soil chronosequence. The P stocks in soils (0–30 cm) started to decrease at the 52 year site. And the P stock depletion reached almost 17.6% at the 120-year site. The loss of P from the soil of the Hailuogou chronosequence was mainly attributed to weathering, plant uptake, and transport by runoff. About 36% P loss was transported into plant biomass P at the 120 year site. The data obtained indicated that the glacier retreat chronosequence could be used to elucidate the fast rate of P loss during the early pedogenic stage. PMID:26557441

  18. Social vulnerability of rural households to flood hazards in western mountainous regions of Henan province, China

    NASA Astrophysics Data System (ADS)

    Liu, Delin; Li, Yue

    2016-05-01

    Evaluating social vulnerability is a crucial issue in risk and disaster management. In this study, a household social vulnerability index (HSVI) to flood hazards was developed and used to assess the social vulnerability of rural households in western mountainous regions of Henan province, China. Eight key indicators were identified using existing literature and discussions with experts from multiple disciplines and local farmers, and their weights were determined using principle component analysis (PCA) and an expert scoring method. The results showed that (1) the ratio of perennial work in other places, hazard-related training and illiteracy ratio (15+) were the most dominant factors of social vulnerability. (2) The numbers of high, moderate and low vulnerability households were 14, 64 and 16, respectively, which accounted for 14.9, 68.1 and 17.0 % of the total interviewed rural households, respectively. (3) The correlation coefficient between household social vulnerability scores and casualties in a storm flood in July 2010 was significant at 0.05 significance level (r = 0.748), which indicated that the selected indicators and their weights were valid. (4) Some mitigation strategies to reduce household social vulnerability to flood hazards were proposed, which included (1) improving the local residents' income and their disaster-related knowledge and evacuation skills, (2) developing emergency plans and carrying out emergency drills and training, (3) enhancing the accuracy of disaster monitoring and warning systems and (4) establishing a specific emergency management department and comprehensive rescue systems. These results can provide useful information for rural households and local governments to prepare, mitigate and respond to flood hazards, and the corresponding strategies can help local households to reduce their social vulnerability and improve their ability to resist flood hazard.

  19. Balancing multiple objectives using a classification-based forest management system in Changbai Mountains, China.

    PubMed

    Zhao, Fuqiang; Yang, Jian; Liu, Zhihua; Dai, Limin; He, Hong S

    2011-12-01

    Contemporary forest management often consists of multiple objectives, including restoration of human-impacted forested landscapes toward their range of natural variability (RNV) and sustainable levels of timber production. Balancing multiple management objectives is often challenging due to intrinsic conflicts between these objectives and a lack of reference conditions for evaluating the effectiveness of forest restoration efforts. We used a spatially explicit forest landscape model to assess how well a classification-based forest management (CFM) system could achieve multiple objectives in a Korean pine broadleaf mixed forest ecosystem at Changbai Mountain in Northeast China. The CFM system divided the forest landscape into three management areas (Commercial Forest, Special Ecological Welfare Forest, and General Ecological Welfare Forest), each with its own management objectives and prescriptions, but with an overall goal of increasing the ecological and economic sustainability of the entire landscape. The zoning approach adopted in the Chinese CFM system is very similar to the TRIAD approach that is being advocated for managing public forests in Canada. In this study, a natural disturbance scenario and seven harvest scenarios (one identical to the current harvest regime and six alternative scenarios) were simulated to examine how tree species composition, age structure, and timber production at the landscape level can be affected by different strategies under the CFM system. The results indicated that the current forest management regime would not only fail to reach the designated timber production level but also move the forest landscape far away from its RNV. In order to return the currently altered forest landscape to approach its RNV while providing a stable level of timber production over time, harvest intensities should be reduced to a level that is equivalent to the amount of timber removals that would occur under the natural disturbances; and the

  20. Rehabilitation of a debris-flow prone mountain stream in southwestern China - Strategies, effects and implications

    NASA Astrophysics Data System (ADS)

    Yu, Guo-an; Huang, He Qing; Wang, Zhaoyin; Brierley, Gary; Zhang, Kang

    2012-01-01

    SummaryRehabilitation of Shengou Creek, a small, steep mountain stream in southwestern China that is prone to debris flows, started more than 30 years ago through an integrated program of engineering applications (check dams and guiding dikes), biological measures (reforestation), and social measures (reducing human disturbance). Small and medium-sized check dams and guiding dikes were constructed on key upper and middle sections of the creek to stabilize hillslopes and channel bed. Meanwhile, Leucaena leucocephala, a drought-tolerant, fast-growing, and highly adaptive plant species, was introduced to promote vegetation recovery in the watershed. The collective community structure of tree, shrub, and herb assemblages in the artificial L. leucocephala forest, which developed after 7 years, enhanced soil structure and drastically reduced soil erosion on hillslopes. Cultivation of steep land was strictly controlled in the basin, and some inhabitants were encouraged to move from upstream areas to downstream towns to reduce disturbance. These integrated measures reduced sediment supply from both hillslopes and upstream channels, preventing sediment-related hazards. The development of natural streambed resistance structures (mainly step-pool systems) and luxuriant riparian vegetation aided channel stability, diversity of stream habitat, and ecological maintenance in the creek. These findings are compared with Jiangjia and Xiaobaini Ravines, two adjacent non-rehabilitated debris-flow streams which have climate and geomorphologic conditions similar to Shengou Creek. Habitat diversity indices, taxa richness, biodiversity, and bio-community indices are much higher in Shengou Creek relative to Jiangjia and Xiaobaini Ravines, attesting to the effectiveness of rehabilitation measures.

  1. Balancing Multiple Objectives Using a Classification-Based Forest Management System in Changbai Mountains, China

    NASA Astrophysics Data System (ADS)

    Zhao, Fuqiang; Yang, Jian; Liu, Zhihua; Dai, Limin; He, Hong S.

    2011-12-01

    Contemporary forest management often consists of multiple objectives, including restoration of human-impacted forested landscapes toward their range of natural variability (RNV) and sustainable levels of timber production. Balancing multiple management objectives is often challenging due to intrinsic conflicts between these objectives and a lack of reference conditions for evaluating the effectiveness of forest restoration efforts. We used a spatially explicit forest landscape model to assess how well a classification-based forest management (CFM) system could achieve multiple objectives in a Korean pine broadleaf mixed forest ecosystem at Changbai Mountain in Northeast China. The CFM system divided the forest landscape into three management areas (Commercial Forest, Special Ecological Welfare Forest, and General Ecological Welfare Forest), each with its own management objectives and prescriptions, but with an overall goal of increasing the ecological and economic sustainability of the entire landscape. The zoning approach adopted in the Chinese CFM system is very similar to the TRIAD approach that is being advocated for managing public forests in Canada. In this study, a natural disturbance scenario and seven harvest scenarios (one identical to the current harvest regime and six alternative scenarios) were simulated to examine how tree species composition, age structure, and timber production at the landscape level can be affected by different strategies under the CFM system. The results indicated that the current forest management regime would not only fail to reach the designated timber production level but also move the forest landscape far away from its RNV. In order to return the currently altered forest landscape to approach its RNV while providing a stable level of timber production over time, harvest intensities should be reduced to a level that is equivalent to the amount of timber removals that would occur under the natural disturbances; and the

  2. Chemical characteristics of precipitation at Nanping Mangdang Mountain in eastern China during spring.

    PubMed

    Cheng, Yanli; Liu, Ying; Huo, Mingqun; Sun, Qian; Wang, Huixiang; Chen, Zhongming; Bai, Yuhua

    2011-01-01

    To study the characteristics of precipitation in eastern China, an automatic sampler was used to collect rainwater samples from 19 precipitation events at Mangdang Mountain, Nanping City, Fujiang Province, in the spring of 2009. We used ion chromatography to analyze the ionic components and concentrations, and inductively coupled plasma mass spectrometry (ICP-MS) to analyze element compositions and contents. The results demonstrated remarkable acidic characteristics: in more than 80% of precipitation events the pH was less than 5.6, with an average of 4.81. Mass concentration results showed SO4(2-) was the main anionic component (36.2% of the total anion mass), while NH4+ was the main cationic component (47.7% of the total cation mass) and main ion for acidity neutralization in the rainwater. Organic acid content accounted for 30.9% of total anion mass. The main trace metals were Ca, K, and Na. The SO4(2-)/NO3- ratio was 1.4, indicating that precipitation in this region was influenced by complex air pollution - the product of individual coal-burning combined with vehicle exhaust pollution. Correlation analysis of the chemical composition of the precipitation indicated that acidity in this region was determined by a combination of all acidic and neutralization ions rather than any single ion component. The results also showed that Na+ and Cl- contributions were mainly by seawater; Mg2+ by seawater and crustal materials; the NH4+, K+, Ca2+, NO3- and SO42- by anthropogenic sources; the trace metals were from the Earth's crust; and organic acids were potentially from combustion of biomass.

  3. Effects of Nitrogen and Phosphorus Additions on Carbon Cycling of Tropical Mountain Rainforests in Hainan, China

    NASA Astrophysics Data System (ADS)

    Lai, J.

    2015-12-01

    Nitrogen (N) and Phosphorus (P) deposition is projected to increase significantly in tropical regions in the coming decades, which has changed and will change the structure and function of ecosystems, and affects on ecosystem Carbon (C) cycle. As an important part in global C cycle, how the C cycle of tropical rainforests will be influenced by the N and P deposition should be focused on. This study simulated N and P deposition in a primary and secondary forest of tropical mountain rainforest in Jianfengling, Hainan, China, during five-year field experiment to evaluate the effects of N and P deposition on C cycling processes and relate characteristics. Six levels of N and P treatments were treated: Control, Low-N, Medium-N, High-N, P and N+P. The relative growth rates (RGR) of tree layer in treatment plots were different from that in control plots after years of N and P addition. Simulated N and P deposition also increased ANPP in primary forest. N and P addition changed the growth of trees by altering soil nutrient and microbial activities. N and P addition increased soil organic carbon (SOC) and total N (TN) content, and significantly increased soil total P (TP) content, not changing soil pH. During the whole process of N and P addition, as net nitrification rate and net N mineralization rate were promoted by N and P addition, and effective N content (nitrate) of soil increased in the plot treated with N treatments compared to the control treatment. The microbial P content was increased by N and P addition, and microbial N was not changed. The increasing N deposition may enhance soil nutrient and stimulate growth of trees, which will lead to an increase of the C sequestration.

  4. Effects of grazing on photosynthetic features and soil respiration of rangelands in the Tianshan Mountains of Northwest China.

    PubMed

    Liu, Hua; Zang, Runguo; Chen, Han Y H

    2016-01-01

    Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respiration in grazed and ungrazed rangelands in the Tianshan Mountains of China. We found that grazing reduced the daily maximum net photosynthetic rate and soil respiration rates by 35% and 15%, respectively. The photosynthetic quantum yield, dark respiratory rate, and water use efficiency of T. repens leaves were reduced in grazed plots by 33.3%, 69.2%, and 21.5%, respectively. Our results demonstrated that grazing reduced carbon assimilation while increasing soil respiration within the rangelands in the Tianshan Mountains. PMID:27452980

  5. Effects of grazing on photosynthetic features and soil respiration of rangelands in the Tianshan Mountains of Northwest China

    PubMed Central

    Liu, Hua; Zang, Runguo; Chen, Han Y. H.

    2016-01-01

    Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respiration in grazed and ungrazed rangelands in the Tianshan Mountains of China. We found that grazing reduced the daily maximum net photosynthetic rate and soil respiration rates by 35% and 15%, respectively. The photosynthetic quantum yield, dark respiratory rate, and water use efficiency of T. repens leaves were reduced in grazed plots by 33.3%, 69.2%, and 21.5%, respectively. Our results demonstrated that grazing reduced carbon assimilation while increasing soil respiration within the rangelands in the Tianshan Mountains. PMID:27452980

  6. Effects of grazing on photosynthetic features and soil respiration of rangelands in the Tianshan Mountains of Northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Zang, Runguo; Chen, Han Y. H.

    2016-07-01

    Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respiration in grazed and ungrazed rangelands in the Tianshan Mountains of China. We found that grazing reduced the daily maximum net photosynthetic rate and soil respiration rates by 35% and 15%, respectively. The photosynthetic quantum yield, dark respiratory rate, and water use efficiency of T. repens leaves were reduced in grazed plots by 33.3%, 69.2%, and 21.5%, respectively. Our results demonstrated that grazing reduced carbon assimilation while increasing soil respiration within the rangelands in the Tianshan Mountains.

  7. The role of anthropogenic and natural factors in shaping the geochemical evolution of groundwater in the Subei Lake basin, Ordos energy base, Northwestern China.

    PubMed

    Liu, Fei; Song, Xianfang; Yang, Lihu; Han, Dongmei; Zhang, Yinghua; Ma, Ying; Bu, Hongmei

    2015-12-15

    Groundwater resources are increasingly exploited for industrial and agricultural purposes in many arid regions globally, it is urgent to gain the impact of the enhanced anthropogenic pressure on the groundwater chemistry. The aim of this study was to acquire a comprehensive understanding of the evolution of groundwater chemistry and to identify the impact of natural and anthropogenic factors on the groundwater chemistry in the Subei Lake basin, Northwestern China. A total of 153 groundwater samples were collected and major ions were measured during the three campaigns (August and December 2013, May 2014). At present, the major hydrochemical facies in unconfined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Na-HCO3, Ca-Mg-SO4 and Na-SO4-Cl types, while the main hydrochemical facies in confined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Ca-HCO3 and Na-HCO3 types. Relatively greater seasonal variation can be observed in the chemical constituents of confined groundwater than that of unconfined groundwater. Rock weathering predominates the evolution of groundwater chemistry in conjunction with the cation exchange, and the dissolution/precipitation of gypsum, halite, feldspar, calcite and dolomite are responsible for the chemical constituents of groundwater. Anthropogenic activities can be classified as: (1) groundwater overexploitation; (2) excessive application of fertilizers in agricultural areas. Due to intensive groundwater pumping, the accelerated groundwater mineralization resulted in the local changes in hydrochemical facies of unconfined groundwater, while the strong mixture, especially a large influx of downward leakage from the unconfined aquifer into the confined aquifer, played a vital role in the fundamental variation of hydrochemical facies in confined aquifer. The nitrate contamination is mainly controlled by the local hydrogeological settings coupled with the traditional flood irrigation. The deeper insight into geochemical evolution of

  8. Rock magnetic properties and paleoenvironmental implications of an 8-Ma Late Cenozoic terrigenous succession from the northern Tian Shan foreland basin, northwestern China

    NASA Astrophysics Data System (ADS)

    Lu, Honghua; Zhang, Weiguo; Li, Youli; Dong, Chenyin; Zhang, Tianqi; Zhou, Zuyi; Zheng, Xiangmin

    2013-12-01

    In the northern Tian Shan foreland basin, northwestern China, the thick Cenozoic terrigenous succession is crucial for paleoclimate-environmental reconstruction of the Asian interior. Here we present a detailed rock magnetic investigation on 245 samples from the ~ 1200-m-thick Neogene Taxi He section with a magnetostratigraphic age span of ca. 8.0 to 2.0 Ma in the northern Tian Shan foreland basin. Our rock magnetic results indicate that the significant variations in composition, concentration and grain size of magnetic minerals occurred at ca. 6.0, 3.7 and 2.7 Ma. The comparable compositions of rare earth elements (REEs) throughout the Neogene Taxi He section suggest no significant modification of the source materials during the interval between ca. 8.0 and 2.0 Ma, and thus sediment provenance is not regarded as responsible for these observed variations in rock magnetic properties. Our further analyses show that the variations in magnetic properties of the Taxi He section are casually linked mainly with lithofacies transition due to range encroachment into foreland basin as well as climate aridification. Identified enhancement of aridification was chronologically constrained at ca. 6.0 and 2.7 Ma. Such climate events are important archives for reconstructing the Late Cenozoic paleoclimatic history of the Asian interior. Further comparison between different paleoclimate records clearly indicates that magnetic parameters such as S- 100mT are potentially effective proxy indices for paleoclimate-environmental reconstruction in the Tian Shan foreland basins and the nearby areas.

  9. Sensitivity of growth and biomass allocation patterns to increasing nitrogen: a comparison between ephemerals and annuals in the Gurbantunggut Desert, north-western China

    PubMed Central

    Zhou, Xiaobing; Zhang, Yuanming; Niklas, Karl J.

    2014-01-01

    Background and Aims Biomass accumulation and allocation patterns are critical to quantifying ecosystem dynamics. However, these patterns differ among species, and they can change in response to nutrient availability even among genetically related individuals. In order to understand this complexity further, this study examined three ephemeral species (with very short vegetative growth periods) and three annual species (with significantly longer vegetative growth periods) in the Gurbantunggut Desert, north-western China, to determine their responses to different nitrogen (N) supplements under natural conditions. Methods Nitrogen was added to the soil at rates of 0, 0·5, 1·0, 3·0, 6·0 and 24·0 g N m−2 year−1. Plants were sampled at various intervals to measure relative growth rate and shoot and root dry mass. Key Results Compared with annuals, ephemerals grew more rapidly, increased shoot and root biomass with increasing N application rates and significantly decreased root/shoot ratios. Nevertheless, changes in the biomass allocation of some species (i.e. Erodium oxyrrhynchum) in response to the N treatment were largely a consequence of changes in overall plant size, which was inconsistent with an optimal partitioning model. An isometric log shoot vs. log root scaling relationship for the final biomass harvest was observed for each species and all annuals, while pooled data of three ephemerals showed an allometric scaling relationship. Conclusions These results indicate that ephemerals and annuals differ observably in their biomass allocation patterns in response to soil N supplements, although an isometric log shoot vs. log root scaling relationship was maintained across all species. These findings highlight that different life history strategies behave differently in response to N application even when interspecific scaling relationships remain nearly isometric. PMID:24287812

  10. Carbon and oxygen isotopic records from Lake Tuosu over the last 120 years in the Qaidam Basin, Northwestern China: The implications for paleoenvironmental reconstruction

    NASA Astrophysics Data System (ADS)

    Li, Xiangzhong; Zhou, Xin; Liu, Weiguo; Wang, Zheng; He, Yuxin; Xu, Liming

    2016-06-01

    Isotopic compositions of total organic carbon (TOC) and authigenic carbonate in lakes have been widely used to reconstruct paleoclimatic changes and the depositional environments of lake sediments. However, since these proxies are often controlled by multiple environmental factors, detailed examinations of modern environmental processes is necessary before further applying them into paleoclimatic studies, especially in arid/semi-arid northwestern China. Here we generate High-resolution multi-proxy sedimentary records from Lake Tuosu, a hydrologically closed, saline and alkaline lake located at the north margin of the Qaidam Basin, through analysis of carbon isotope of TOC, and δ18O and δ13C values of ostracods over the last 120 years. Together with the meteorological data (precipitation and temperature), lake area record, and other tree-ring evidence, we examine how these sedimentary indices respond to changes in hydrologic balance and climate at interannual to decadal timescales. We found that sedimentary δ13Corg values resemble the variation of lake areas of Lake Tuosu over the last 40 years, suggesting that δ13Corg values would be an ideal indicator of lake area/level fluctuations and thus effective moisture variations (precipitation vs. evaporation). However, ostracod δ18O, which was previously used as proxies of effective precipitation, is not well correlated with δ13Corg values in Lake Tuosu. Therefore, the changes of ostracod δ18O values cannot be straightforwardly explained as the effective precipitation. Instead, the isotopic composition of carbonate would be additionally controlled by other factors including isotopic compositions of input water and drainage pattern.

  11. Geochronology of the Hongniu-Hongshan porphyry and skarn Cu deposit, northwestern Yunnan province, China: Implications for mineralization of the Zhongdian arc

    NASA Astrophysics Data System (ADS)

    Peng, Hui-juan; Mao, Jing-wen; Pei, Rong-fu; Zhang, Chang-qing; Tian, Guang; Zhou, Yunman; Li, Jianxin; Hou, Lin

    2014-01-01

    The Hongniu-Hongshan porphyry and skarn copper deposit is located in the Triassic Zhongdian island arc, northwestern Yunnan province, China. Single-zircon laser ablation inductively coupled plasma mass spectrometry U-Pb dating suggests that the diorite porphyry and the quartz monzonite porphyry in the deposit area formed at 200 Ma and 77 Ma, respectively. A Re-Os isotopic date of molybdenite from the ore is 78.9 Ma, which indicates that in addition to the known Triassic Cu-(Au) porphyry systems, a Late Cretaceous porphyry Cu-Mo mineralization event also exists in the Zhongdian arc. The quartz monzonite porphyry shows characteristics of a magnetite series intrusion, with a high concentration of Al, K, Rb, Ba, and Pb, low amount of Ta, Ti, Y, and Yb, and a high ratio of Sr/Y (average 26.42). The Cretaceous porphyry also shows a strong fractionation between light and heavy rare earth elements (average (La/Yb)N 37.9), which is similar to those of the Triassic subduction-related diorite porphyry in the Hongniu-Hongshan deposit and the porphyry hosting the Pulang copper deposit. However, in contrast to the older intrusions, the quartz monzonite porphyry contains higher concentrations of large ion lithophile elements and Co, and lesser Sr and Zr. Therefore, whereas the Triassic porphyry Cu-(Au) mineralization is related to slab subduction slab in an arc setting, the quartz monzonite porphyry in the Hongniu-Hongshan deposit formed by the remelting of the residual oceanic slab combined with contributions from subduction-modified arc lithosphere and continental crust, which provided the metals for the Late Cretaceous mineralization.

  12. Vertical distributions of radionuclides ((239+240)Pu, (240)Pu/(239)Pu, and (137)Cs) in sediment cores of Lake Bosten in Northwestern China.

    PubMed

    Liao, Haiqing; Bu, Wenting; Zheng, Jian; Wu, Fengchang; Yamada, Masatoshi

    2014-04-01

    Artificial radionuclides ((137)Cs, (239+240)Pu, (241)Pu, (241)Am) deposited in lacustrine sediments have been used for dating as well as radionuclide source identification. In the present work, we investigated the vertical distributions of (239+240)Pu and (137)Cs activities, (240)Pu/(239)Pu atom ratios, and (239+240)Pu/(137)Cs activity ratios in sediment cores collected from Lake Bosten, which is the lake closest to the Lop Nor Chinese Nuclear Weapon Test site in northwestern China. Uniformly high concentrations of (239+240)Pu and (137)Cs were found in the upper layers deposited since 1964 in the sediment cores, and these were controlled by the resuspension of soil containing radionuclides from the nearby land surface. As the Chinese nuclear tests varied remarkably in yield, the mixing of the tropospheric deposition from these tests and the stratospheric deposition of global fallout has led to a (240)Pu/(239)Pu atom ratio that is similar to that of global fallout and to a (239+240)Pu/(137)Cs activity ratio that is slightly higher than that of global fallout. However, a low (240)Pu/(239)Pu atom ratio of 0.080 and high (239+240)Pu/(137)Cs activity ratio of 0.087, significantly different from the global fallout values, were observed in one sediment core (07BS10-2), indicating the inhomogenous tropospheric deposition from the Chinese nuclear tests in Lake Bosten during 1967-1973. These results are important to understand the influence of the CNTs on the radionuclide contamination in Lake Bosten.

  13. Interdecadal Variations of East Asian Monsoon as Inferred by Tree-ring Data From Northeastern Qaidam Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Shao, X.; Huang, L.; Yin, Z.; Guo, Q.

    2006-12-01

    East Asian monsoon is crucial for modulating the climate in China. Especially, the summer monsoon is closely related to the severe flood and drought events in eastern China. To study the characteristics of summer monsoon a long-term record is needed. In this study we attempted to examine the interdecadal variations of East Asian monsoon by using tree-ring data. The summer monsoon index (Ism) for the period of 1873- 2000 was calculated using sea level pressure data. Firstly, we calculated the difference (ΔP) of the sea level pressure between the land (110ºE) and sea (160ºE) from 10ºN to 50ºN with 5º intervals. Then the ΔP values that are smaller than or equal to -5 hPa in June, July and August were summed and defined as the Ism. By this definition Ism values greater than 1.0 represent strong monsoon conditions, and vice versa. Sea level pressure data prior to 1951 were obtained from the Meteorological Office of United Kingdom, and that afterwards were from the NCEP data set. The tree ring data of Qilian junipers (Sabina przewalskii Kom.) are from the northeastern part of the Qaidam Basin, located along the northeastern margin of the Qinghai-Tibetan Plateau. These tree-ring data have been used to reconstruct local precipitation and soil moisture conditions. Previous studies have revealed that there was a teleconnection in rainfall between eastern China and the Qinghai-Tibetan Plateau. We examined the relationships of the ring-width series with the Ism series over the common period of 1873-2000 AD. We found that the tree-ring widths were statistical significantly correlated with Ism. These negative correlations increased significantly after a low-pass filter was used for both data sets, indicating very good potential for reconstruction of low-frequency variations of Ism in the past. Variability of the Ism series and ring-width series were examined using power spectrum analysis and wavelet transformation. The reconstructed Ism values during the period 1440

  14. Incorporating topography in a cellular automata model to simulate residents evacuation in a mountain area in China

    NASA Astrophysics Data System (ADS)

    Wang, Li; Liu, Mao; Meng, Bo

    2013-02-01

    In China, both the mountainous areas and the number of people who live in mountain areas occupy a significant proportion. When production accidents or natural disasters happen, the residents in mountain areas should be evacuated and the evacuation is of obvious importance to public safety. But it is a pity that there are few studies on safety evacuation in rough terrain. The particularity of the complex terrain in mountain areas, however, makes it difficult to study pedestrian evacuation. In this paper, a three-dimensional surface cellular automata model is proposed to numerically simulate the real time dynamic evacuation of residents. The model takes into account topographic characteristics (the slope gradient) of the environment and the biomechanics characteristics (weight and leg extensor power) of the residents to calculate the walking speed. This paper only focuses on the influence of topography and the physiological parameters are defined as constants according to a statistical report. Velocity varies with the topography. In order to simulate the behavior of a crowd with varying movement velocities, and a numerical algorithm is used to determine the time step of iteration. By doing so, a numerical simulation can be conducted in a 3D surface CA model. Moreover, considering residents evacuation around a gas well in a mountain area as a case, a visualization system for a three-dimensional simulation of pedestrian evacuation is developed. In the simulation process, population behaviors of congestion, queuing and collision avoidance can be observed. The simulation results are explained reasonably. Therefore, the model presented in this paper can realize a 3D dynamic simulation of pedestrian evacuation vividly in complex terrain and predict the evacuation procedure and evacuation time required, which can supply some valuable information for emergency management.

  15. Multiple origins for the Middle Jurassic to Early Cretaceous high-K calc-alkaline I-type granites in northwestern Fujian province, SE China and tectonic implications

    NASA Astrophysics Data System (ADS)

    Wang, Guo-Chang; Jiang, Yao-Hui; Liu, Zheng; Ni, Chun-Yu; Qing, Long; Zhang, Qiao; Zhu, Shu-Qi

    2016-03-01

    A comprehensive study of zircon U-Pb dating and in situ Hf isotopes, whole-rock major and trace element geochemistry and Sr-Nd isotopes was carried out for three late Mesozoic granitic plutons (Waitun, Shipi and Taiyuan) in northwestern Fujian province, SE China. We assess the origin of the granites and their relationship to the evolution of the late Mesozoic volcanic-intrusive complex belt in SE China. LA-ICP-MS zircon U-Pb dating shows that three plutons were emplaced in the Middle Jurassic to Early Cretaceous (168-109 Ma), in which the Waitun and Shipi plutons are intrusive complexes. All the plutons are composed of high-K calc-alkaline I-type granites with a great diversity in elemental and isotopic compositions. The granites have SiO2 contents of 68.3-78.5 wt.%, showing a gradual decrease in initial 87Sr/86Sr (0.7181 to 0.7091) and increase in εNd (T) (- 16.7 to - 8.1) and εHf (T) (in-situ zircon) (- 20.6 to - 6.9) with decreasing emplacement ages. Geochemical data suggest that the Middle Jurassic (~ 168 Ma) Waitun granites are of purely crustal origin, derived by partial melting of a mixed source of Paleoproterozoic metaigneous (~ 78%) and metasedimentary (~ 22%) rocks at a depth of 30-40 km triggered by underplating of basaltic magma. Mixing of such crustal melts with about 10% basaltic magma could account for the origin of the Late Jurassic (~ 161 Ma) Waitun granites. The Late Jurassic (~ 156 Ma) Shipi and Early Cretaceous (~ 134 Ma) Taiyuan granites were produced by extensive fractional crystallization of primary crustal melts, the source of which show relatively high proportion (~ 82%) of metaigneous rocks. The Early Cretaceous (~ 109 Ma) Shipi granites were generated by partial melting of a mixed source of Paleoproterozoic metaigneous (~ 92%) and metasedimentary (~ 8%) rocks at a depth of ~ 30 km plus additional (~ 15%) input from coeval basaltic magma. The granites were formed in a continental arc setting induced by northwestward subduction of the

  16. Sustainable management of river oases along the Tarim River in North-Western China under conditions of climate change

    NASA Astrophysics Data System (ADS)

    Rumbaur, C.; Thevs, N.; Disse, M.; Ahlheim, M.; Brieden, A.; Cyffka, B.; Doluschitz, R.; Duethmann, D.; Feike, T.; Frör, O.; Gärtner, P.; Halik, Ü.; Hill, J.; Hinnenthal, M.; Keilholz, P.; Kleinschmit, B.; Krysanova, V.; Kuba, M.; Mader, S.; Menz, C.; Othmanli, H.; Pelz, S.; Schroeder, M.; Siew, T. F.; Stender, V.; Stahr, K.; Thomas, F. M.; Welp, M.; Wortmann, M.; Zhao, X.; Chen, X.; Jiang, T.; Zhao, C.; Zhang, X.; Luo, J.; Yimit, H.; Yu, R.

    2014-10-01

    The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of China and one of the largest in whole Central Asia. Due to the extremely arid climate with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim River solely depends on river water. This applies for anthropogenic activities (e.g. agriculture) as well as for the natural ecosystems so that both compete for water. The on-going increase of water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes formed the consortium SuMaRiO (www.sumario.de), which aims at gaining a holistic picture of the availability of water resources in the Tarim River Basin and the impacts on anthropogenic activities and natural ecosystems caused by the water distribution within the Tarim River Basin. The discharge of the Aksu River, which is the major tributary to the Tarim, has been increasing over the past 6 decades due to enhanced glacier melt. Alone from 1989 to 2011, the area under agriculture more than doubled. Thereby, cotton became the major crop and there was a shift from small-scale farming to large-scale intensive farming. The major natural ecosystems along the Aksu and Tarim River are riparian ecosystems: Riparian (Tugai) forests, shrub vegetation, reed beds, and other grassland. Within the SuMaRiO Cluster the focus was laid on the Tugai forests, with Populus euphratica as dominant tree, because the most productive and species-rich natural ecosystems can be found among those forests. On sites with groundwater distance of less than 7.5 m the annual increments correlated with river runoffs of the previous year. But, the further downstream along the Tarim River, the more the natural river dynamics ceased, which impacts on the recruitment of

  17. Size-related change in Nitraria sphaerocarpa patches shifts the shrub-annual interaction in an arid desert, northwestern China

    NASA Astrophysics Data System (ADS)

    Zhang, Gefei; Yang, Qiyue; Wang, Xiaofen; Zhao, Wenzhi

    2015-11-01

    In arid and semi-arid ecosystems, the effect of shrubs on their understory plants has been frequently reported. Many previous studies have shown that both facilitation and competition act simultaneously, and their balance changes in response to spatial or temporal variations in environmental stresses. Yet, we know little about how the interaction varies between shrubs and their understory plants in vegetation patches with different characteristics. Here, an empirical investigation was conducted in Hexi desert region of northwest China, to evaluate how the net effect of Nitraria sphaerocarpa shrubs on the herbaceous species varies across different sizes of N. sphaerocarpa patches. Our study showed that herbaceous species perform better on small shrub patches. But the magnitude of this facilitative effect decreased with increasing patch size, and finally shifted to interference in large patches. The results indicated that these negative shifts in plant interactions were not clearly related to 'shrub-island effect' in terms of nutrient accumulation or soil properties improvement, but may be explained by the variation in other abiotic factors, such as soil moisture and available light. Changes in root distribution and canopy structure of N. sphaerocarpa shrubs with the increase of patch size seem to also partly explain the variation in shrub-understory species interactions, as a result of increased above- and below-ground niche overlaps.

  18. Organic molecular compositions and temporal variations of summertime mountain aerosols over Mt. Tai, North China Plain

    NASA Astrophysics Data System (ADS)

    Fu, Pingqing; Kawamura, Kimitaka; Okuzawa, Kazuhiro; Aggarwal, Shankar Gopala; Wang, Gehui; Kanaya, Yugo; Wang, Zifa

    2008-10-01

    Total suspended particles (TSP) were collected at the summit of Mt. Tai (1534 m above sea level) on a daytime and nighttime basis during a summertime campaign (May-June 2006) and were characterized for organic molecular compositions using solvent extraction/derivatization and gas chromatography/mass spectrometry technique. The n-Alkanes, fatty acids, fatty alcohols, sugars, glycerol and polyacids, and phthalate esters were found as major organic compound classes, whereas lignin and resin products, sterols, aromatic acids, hopanes, and polycyclic aromatic hydrocarbons (PAHs) were detected as minor classes. Sugars (49.8-2115 ng m-3, average 640 ng m-3 in daytime; 18.1-4348 ng m-3, 799 ng m-3 in nighttime) were found to be the dominant compound class. Levoglucosan, a specific cellulose pyrolysis product, was detected as the most abundant single compound, followed by C28 fatty alcohol, diisobutyl and di-n-butyl phthalates, C29n-alkane, C16 and C28 fatty acids, and malic acid. By grouping organic compounds based on their sources, we found that emission of terrestrial plant waxes was the most significant source (30-34%) of the TSP, followed by biomass burning products (25-27%) (e.g., levoglucosan and lignin and resin products), soil resuspension (15-18%) due to agricultural activities, secondary oxidation products (8-10%), plastic emission (3-10%), marine/microbial sources (6%), and urban/industrial emissions from fossil fuel use (4%). However, low molecular weight dicarboxylic acids (such as oxalic acid) of photochemical origin were not included in this study. Malic acid was found to be much higher than those reported in the ground level, suggesting an enhanced photochemical production in the free troposphere over mountain areas. Temporal variations of biomass burning tracers (e.g., levoglucosan, galactosan, mannosan) and some higher plant wax derived compound classes suggested that there were two major (E1 and E2) and one minor (E3) biomass-burning events during this

  19. Elemental responses to subduction-zone metamorphism: Constraints from the North Qilian Mountain, NW China

    NASA Astrophysics Data System (ADS)

    Xiao, Yuanyuan; Niu, Yaoling; Song, Shuguang; Davidson, Jon; Liu, Xiaoming

    2013-02-01

    Subduction zone metamorphism (SZM) and behaviors of chemical elements in response to this process are important for both arc magmatism and mantle compositional heterogeneity. In this paper, we report the results of our petrographic and geochemical studies on blueschist and eclogite facies rocks of sedimentary and basaltic protoliths from two metamorphic sub-belts with different metamorphic histories in the North Qilian Mountain, Northwest China. The protolith of low-grade blueschists is basaltic in composition and is most likely produced in a back-arc setting, while the protoliths of high-grade blueschists/eclogites geochemically resemble the present-day normal and enriched mid-oceanic ridge basalts plus some volcanic arc rocks. The meta-sedimentary rocks, including meta-graywacke, meta-pelite, meta-chert and marble, show geochemical similarity to global oceanic (subducted) sediments. Assuming that high field strength elements (HFSEs) are relatively immobile, the correlated variations of rare earth elements (REEs) and Th with HFSEs suggest that all these elements are probably also immobile, whereas Pb and Sr are mobile in rocks of both basaltic and sedimentary protoliths during SZM. Ba, Cs and Rb are immobile in rocks of sedimentary protoliths and mobile in rocks of basaltic protolith. The apparent mobility of U in rocks of basaltic protolith may be inherited from seafloor alterations rather than caused by SZM. On the basis of in situ mineral compositional analysis (both major and trace elements), the most significant trace element storage minerals in these subduction-zone metamorphic rocks are: lawsonite, pumpellyite, apatite, garnet and epidote group minerals for REEs, white micas (both phengite and paragonite) for large ion lithophile elements, rutile and titanite for HFSEs. The presence and stability of these minerals exert the primary controls on the geochemical behaviors of most of these elements during SZM. The immobility of REEs, Th and U owing to their

  20. Elevation-dependent variations of tree growth and intrinsic water-use efficiency in Schrenk spruce (Picea schrenkiana) in the western Tianshan Mountains, China.

    PubMed

    Wu, Guoju; Liu, Xiaohong; Chen, Tuo; Xu, Guobao; Wang, Wenzhi; Zeng, Xiaomin; Zhang, Xuanwen

    2015-01-01

    Rising atmospheric CO2 concentration (C a) is expected to accelerate tree growth by enhancing photosynthesis and increasing intrinsic water-use efficiency (iWUE). However, the extent of this effect on long-term iWUE and its interactions with climate remains unclear in trees along an elevation gradient. Therefore, we investigated the variation in the radial growth and iWUE of mature Picea schrenkiana trees located in the upper tree-line (A1: 2700 m a.s.l.), middle elevation (A2: 2400 m a.s.l.), and lower forest limit (A3: 2200 m a.s.l.), in relation to the rising C a and changing climate in the Wusun Mountains of northwestern China, based on the basal area increment (BAI) and tree-ring δ(13)C chronologies from 1960 to 2010. We used the CRU TS3.22 dataset to analyze the general response of tree growth to interannual variability of regional climate, and found that BAI and δ(13)C are less sensitive to climate at A1 than at A2 and A3. The temporal trends of iWUE were calculated under three theoretical scenarios, as a baseline for interpreting the observed gas exchange at increasing C a. We found that iWUE increased by 12-32% from A1 to A3 over the last 50 years, and showed an elevation-dependent variation in physiological response. The significant negative relationship between BAI and iWUE at A2 and A3 showed that tree growth has been decreasing despite long-term increases in iWUE. However, BAI remained largely stable throughout the study period despite the strongest iWUE increase [at constant intercellular CO2 concentration (C i) before 1980] at A1. Our results indicate a drought-induced limitation of tree growth response to rising CO2 at lower elevations, and no apparent change in tree growth and diminished iWUE improvement since 1980 in the upper tree-line. This study may contradict the expectation that combined effects of elevated C a and rising temperatures have increased forest productivity, especially in high-elevation forests.

  1. Elevation-dependent variations of tree growth and intrinsic water-use efficiency in Schrenk spruce (Picea schrenkiana) in the western Tianshan Mountains, China

    PubMed Central

    Wu, Guoju; Liu, Xiaohong; Chen, Tuo; Xu, Guobao; Wang, Wenzhi; Zeng, Xiaomin; Zhang, Xuanwen

    2015-01-01

    Rising atmospheric CO2 concentration (Ca) is expected to accelerate tree growth by enhancing photosynthesis and increasing intrinsic water-use efficiency (iWUE). However, the extent of this effect on long-term iWUE and its interactions with climate remains unclear in trees along an elevation gradient. Therefore, we investigated the variation in the radial growth and iWUE of mature Picea schrenkiana trees located in the upper tree-line (A1: 2700 m a.s.l.), middle elevation (A2: 2400 m a.s.l.), and lower forest limit (A3: 2200 m a.s.l.), in relation to the rising Ca and changing climate in the Wusun Mountains of northwestern China, based on the basal area increment (BAI) and tree-ring δ13C chronologies from 1960 to 2010. We used the CRU TS3.22 dataset to analyze the general response of tree growth to interannual variability of regional climate, and found that BAI and δ13C are less sensitive to climate at A1 than at A2 and A3. The temporal trends of iWUE were calculated under three theoretical scenarios, as a baseline for interpreting the observed gas exchange at increasing Ca. We found that iWUE increased by 12–32% from A1 to A3 over the last 50 years, and showed an elevation-dependent variation in physiological response. The significant negative relationship between BAI and iWUE at A2 and A3 showed that tree growth has been decreasing despite long-term increases in iWUE. However, BAI remained largely stable throughout the study period despite the strongest iWUE increase [at constant intercellular CO2 concentration (Ci) before 1980] at A1. Our results indicate a drought-induced limitation of tree growth response to rising CO2 at lower elevations, and no apparent change in tree growth and diminished iWUE improvement since 1980 in the upper tree-line. This study may contradict the expectation that combined effects of elevated Ca and rising temperatures have increased forest productivity, especially in high-elevation forests. PMID:25999973

  2. Elevation-dependent variations of tree growth and intrinsic water-use efficiency in Schrenk spruce (Picea schrenkiana) in the western Tianshan Mountains, China.

    PubMed

    Wu, Guoju; Liu, Xiaohong; Chen, Tuo; Xu, Guobao; Wang, Wenzhi; Zeng, Xiaomin; Zhang, Xuanwen

    2015-01-01

    Rising atmospheric CO2 concentration (C a) is expected to accelerate tree growth by enhancing photosynthesis and increasing intrinsic water-use efficiency (iWUE). However, the extent of this effect on long-term iWUE and its interactions with climate remains unclear in trees along an elevation gradient. Therefore, we investigated the variation in the radial growth and iWUE of mature Picea schrenkiana trees located in the upper tree-line (A1: 2700 m a.s.l.), middle elevation (A2: 2400 m a.s.l.), and lower forest limit (A3: 2200 m a.s.l.), in relation to the rising C a and changing climate in the Wusun Mountains of northwestern China, based on the basal area increment (BAI) and tree-ring δ(13)C chronologies from 1960 to 2010. We used the CRU TS3.22 dataset to analyze the general response of tree growth to interannual variability of regional climate, and found that BAI and δ(13)C are less sensitive to climate at A1 than at A2 and A3. The temporal trends of iWUE were calculated under three theoretical scenarios, as a baseline for interpreting the observed gas exchange at increasing C a. We found that iWUE increased by 12-32% from A1 to A3 over the last 50 years, and showed an elevation-dependent variation in physiological response. The significant negative relationship between BAI and iWUE at A2 and A3 showed that tree growth has been decreasing despite long-term increases in iWUE. However, BAI remained largely stable throughout the study period despite the strongest iWUE increase [at constant intercellular CO2 concentration (C i) before 1980] at A1. Our results indicate a drought-induced limitation of tree growth response to rising CO2 at lower elevations, and no apparent change in tree growth and diminished iWUE improvement since 1980 in the upper tree-line. This study may contradict the expectation that combined effects of elevated C a and rising temperatures have increased forest productivity, especially in high-elevation forests. PMID:25999973

  3. Precipitation and Air Pollution at Mountain and Plain Stations in Northern China: Insights Gained from Observations and Modeling

    SciTech Connect

    Guo, Jianping; Deng, Minjun; Fan, Jiwen; Li, Zhanqing; Chen, Qian; Zhai, Panmao; Dai, Zhijian; Li, Xiaowen

    2014-04-27

    We analyzed 40 year data sets of daily average visibility (a proxy for surface aerosol concentration) and hourly precipitation at seven weather stations, including three stations located on the Taihang Mountains, during the summertime in northern China. There was no significant trend in summertime total precipitation at almost all stations. However, light rain decreased, whereas heavy rain increased as visibility decreased over the period studied. The decrease in light rain was seen in both orographic-forced shallow clouds and mesoscale stratiform clouds. The consistent trends in observed changes in visibility, precipitation, and orographic factor appear to be a testimony to the effects of aerosols. The potential impact of large-scale environmental factors, such as precipitable water, convective available potential energy, and vertical wind shear, on precipitation was investigated. No direct links were found. To validate our observational hypothesis about aerosol effects, Weather Research and Forecasting model simulations with spectral-bin microphysics at the cloud-resolving scale were conducted. Model results confirmed the role of aerosol indirect effects in reducing the light rain amount and frequency in the mountainous area for both orographic-forced shallow clouds and mesoscale stratiform clouds and in eliciting a different response in the neighboring plains. The opposite response of light rain to the increase in pollution when there is no terrain included in the model suggests that orography is likely a significant factor contributing to the opposite trends in light rain seen in mountainous and plain areas.

  4. Characteristics, source apportionment and reactivity of ambient volatile organic compounds at Dinghu Mountain in Guangdong Province, China.

    PubMed

    Wu, Fangkun; Yu, Ye; Sun, Jie; Zhang, Junke; Wang, Jian; Tang, Guiqian; Wang, Yuesi

    2016-04-01

    Volatile organic compounds (VOCs) play a very important role in the formation of ozone and secondary organic aerosols. The concentrations, compositions, and variability of VOCs were measured from 2005 to 2008 at Dinghu Mountain Forest Ecosystem Research Station, a remote station in Southeast China. Weekly samples were collected in the Dinghu Mountain area and were analysed via gas chromatography-mass spectrometry. The results revealed that the total VOC concentrations decreased continuously and that the dominant VOC components were alkanes (43%) and aromatics (33%), followed by halo-hydrocarbons (12%) and alkenes (12%). The general trend of seasonal variation indicated higher concentrations in spring and lower concentrations in summer. The positive matrix factorization model was used to identify the sources of the VOCs. Seven sources were resolved by the PMF model: (1) vehicular emissions, which contributed 25% of the total VOC concentration; (2) industrial sources and regional transportation, contributing 17%; (3) paint solvent use, contributing 17%; (4) fuel evaporation, contributing 13%; (5) stationary combustion sources, contributing 12%; (6) biogenic emissions, contributing 10%; and aged VOCs, contributing only 6%. The HYSPLIT model was used to analyse the effect of pollutant transport, and the results indicated that the transport of pollutants from cities cannot be ignored. Finally, the OH radical loss rates and ozone formation potentials (OFPs) were calculated, and the results indicated isoprene to have the highest OH radical loss rate and toluene to be the largest contributor to the OFP at the Dinghu Mountain site. PMID:26803733

  5. Neogene magnetostratigraphy and rock magnetic study of the Kashi Depression, NW China: Implications to neotectonics in the SW Tianshan Mountains

    NASA Astrophysics Data System (ADS)

    Qiao, Qingqing; Huang, Baochun; Piper, John D. A.; Deng, Tao; Liu, Chengying

    2016-03-01

    The southwest Tianshan Mountains of China are bordered by the Tarim foreland and comprise an actively deforming segment of the India-Asia collisional system. We report a detailed magnetostratigraphic study of the Dashankou section in the Kashi Depression of the Tarim Basin to improve the understanding of the history of sedimentation, denudation, and mountain building in this region. The preferred correlation of the succession with the geomagnetic polarity timescale defines a depositional history between 12.4 and 3.0 Ma with a substantial increase in sedimentation rates identified at ~6.7 Ma corresponding to a pulse of rapid uplift in the southwest Tianshan Mountains. Although climatic changes may have modulated the record during Neogene times, they do not appear to have had an important influence on sediment accumulation rates between 7.0 and 2.6 Ma. Magnetic fabrics identify the influence of a regional stress field imparted by ongoing India-Asia collision in the lower part of the succession contrasting with predominantly sedimentary fabrics in the higher part of the succession. A major clastic influx with a maximum age estimate of ~3.6 Ma comprises the Xiyu conglomerates, and integration with other magnetostratigraphic investigations around the Tianshan demonstrates unambiguously that depositional onset of this coarse clastic episode is diachronous. Hence, the Xiyu Formation cannot be considered as a chronostratigraphic marker related to any specific tectonic or climatic event.

  6. Characteristics, source apportionment and reactivity of ambient volatile organic compounds at Dinghu Mountain in Guangdong Province, China.

    PubMed

    Wu, Fangkun; Yu, Ye; Sun, Jie; Zhang, Junke; Wang, Jian; Tang, Guiqian; Wang, Yuesi

    2016-04-01

    Volatile organic compounds (VOCs) play a very important role in the formation of ozone and secondary organic aerosols. The concentrations, compositions, and variability of VOCs were measured from 2005 to 2008 at Dinghu Mountain Forest Ecosystem Research Station, a remote station in Southeast China. Weekly samples were collected in the Dinghu Mountain area and were analysed via gas chromatography-mass spectrometry. The results revealed that the total VOC concentrations decreased continuously and that the dominant VOC components were alkanes (43%) and aromatics (33%), followed by halo-hydrocarbons (12%) and alkenes (12%). The general trend of seasonal variation indicated higher concentrations in spring and lower concentrations in summer. The positive matrix factorization model was used to identify the sources of the VOCs. Seven sources were resolved by the PMF model: (1) vehicular emissions, which contributed 25% of the total VOC concentration; (2) industrial sources and regional transportation, contributing 17%; (3) paint solvent use, contributing 17%; (4) fuel evaporation, contributing 13%; (5) stationary combustion sources, contributing 12%; (6) biogenic emissions, contributing 10%; and aged VOCs, contributing only 6%. The HYSPLIT model was used to analyse the effect of pollutant transport, and the results indicated that the transport of pollutants from cities cannot be ignored. Finally, the OH radical loss rates and ozone formation potentials (OFPs) were calculated, and the results indicated isoprene to have the highest OH radical loss rate and toluene to be the largest contributor to the OFP at the Dinghu Mountain site.

  7. Mesozoic non-marine petroleum source rocks determined by palynomorphs in the Tarim Basin, Xinjiang, northwestern China

    USGS Publications Warehouse

    Jiang, D.-X.; Wang, Y.-D.; Robbins, E.I.; Wei, J.; Tian, N.

    2008-01-01

    The Tarim Basin in Northwest China hosts petroleum reservoirs of Cambrian, Ordovician, Carboniferous, Triassic, Jurassic, Cretaceous and Tertiary ages. The sedimentary thickness in the basin reaches about 15 km and with an area of 560000 km2, the basin is expected to contain giant oil and gas fields. It is therefore important to determine the ages and depositional environments of the petroleum source rocks. For prospective evaluation and exploration of petroleum, palynological investigations were carried out on 38 crude oil samples collected from 22 petroleum reservoirs in the Tarim Basin and on additionally 56 potential source rock samples from the same basin. In total, 173 species of spores and pollen referred to 80 genera, and 27 species of algae and fungi referred to 16 genera were identified from the non-marine Mesozoic sources. By correlating the palynormorph assemblages in the crude oil samples with those in the potential source rocks, the Triassic and Jurassic petroleum source rocks were identified. Furthermore, the palynofloras in the petroleum provide evidence for interpretation of the depositional environments of the petroleum source rocks. The affinity of the miospores indicates that the petroleum source rocks were formed in swamps in brackish to lacustrine depositional environments under warm and humid climatic conditions. The palynomorphs in the crude oils provide further information about passage and route of petroleum migration, which is significant for interpreting petroleum migration mechanisms. Additionally, the thermal alternation index (TAI) based on miospores indicates that the Triassic and Jurassic deposits in the Tarim Basin are mature petroleum source rocks. ?? Cambridge University Press 2008.

  8. Major Fault Systems and Mountain Building Processes in the Tibetan Foreland and Beishan Region, NW China

    NASA Astrophysics Data System (ADS)

    Cunningham, D.; Zhang, J.

    2012-04-01

    In regions north of Tibet, active deformation associated with the Indo-Eurasia collision is diffusely distributed within large areas of NW China, Mongolia and S and SE Siberia. These regions are dominated by intraplate strike-slip and transpressional reactivation of Palaeozoic terrane collages. Because of relatively low historical seismicity, the Beishan region immediately north of Tibet is generally regarded as tectonically uninteresting from a neotectonic standpoint. However, our preliminary work in the region coupled with satellite image analysis indicates that the region is cut by at least five major sinistral strike-slip fault systems that are potentially active and which parallel the Altyn Tagh fault which bounds northern Tibet directly to the south. These fault systems generate localised uplifts within the Beishan and show typical geomorphological characteristics of active intracontinental deforming belts such as sharply defined mountain fronts, Quaternary alluvial fan complexes and tilted Cretaceous peneplain remnants. Specifically, the Yushi Shan and Mazong Shan are Late Cenozoic restraining bends that show clear evidence for Quaternary thrusting and uplift. Other minor localised uplifts also appear fault-controlled. However, at first-order, regional Beishan topography is difficult to explain by Late Cenozoic upper crustal faulting, unlike Tibet to the south and the Gobi Altai to the north. Directly adjacent to Tibet's northern margin, the Sanweishan and Nanjieshan blocks are thrust-bound basement-cored uplifts that interrupt the Tibetan sedimentary foreland in the Dunhuang-Anxi region. The faults that cut and bound these minor ranges appear to define an evolving transpressional duplex with north-directed thrusting, but perhaps surprisingly, also south-directed thrusting back towards the high Plateau. As noted by others, the Altyn Tagh Fault defines a profound topographic and structural boundary in Central Asia with significant differences in contractional

  9. Epic landslide erosion from mountain roads in Yunnan, China – challenges for sustainable development

    EPA Science Inventory

    Expanding systems of mountain roads in developing countries significantly increase the risk of landslides and sedimentation in streams and rivers, as well as create vulnerabilities for residents and aquatic resources. However, neither government agencies nor external assistance o...

  10. Use of the lichen Xanthoria mandschurica in monitoring atmospheric elemental deposition in the Taihang Mountains, Hebei, China.

    PubMed

    Liu, Hua-Jie; Zhao, Liang-Cheng; Fang, Shi-Bo; Liu, Si-Wa; Hu, Jian-Sen; Wang, Lei; Liu, Xiao-Di; Wu, Qing-Feng

    2016-01-01

    Air pollution is a major concern in China. Lichens are a useful biomonitor for atmospheric elemental deposition but have rarely been used in North China. The aim of this study was to investigate the atmospheric depositions of 30 trace elements (Al, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Sc, Sm, Sr, Tb, Th, Ti, Tl, V and Zn) in a region of the Taihang Mountains, Hebei Province, China using lichens as biomonitors. Epilithic foliose lichen Xanthoria mandschurica was sampled from 21 sites and analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that 1) eight elements (Cd, Cr, Cu, Mo, P, Pb, Sb and Zn) are of atmospheric origin and are highly influenced by the atmospheric transportation from the North China Plain, as well as local mining activities, while 2) the remaining 22 elements are primarily of crustal origin, the concentration of which has been enhanced by local mining and quarrying activities. These results clearly validate the applicability of lichens in biomonitoring of atmospheric elemental deposition and demonstrate the spatial pattern for air pollution in the region. PMID:27089945

  11. Use of the lichen Xanthoria mandschurica in monitoring atmospheric elemental deposition in the Taihang Mountains, Hebei, China

    PubMed Central

    Liu, Hua-Jie; Zhao, Liang-Cheng; Fang, Shi-Bo; Liu, Si-Wa; Hu, Jian-Sen; Wang, Lei; Liu, Xiao-Di; Wu, Qing-Feng

    2016-01-01

    Air pollution is a major concern in China. Lichens are a useful biomonitor for atmospheric elemental deposition but have rarely been used in North China. The aim of this study was to investigate the atmospheric depositions of 30 trace elements (Al, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Sc, Sm, Sr, Tb, Th, Ti, Tl, V and Zn) in a region of the Taihang Mountains, Hebei Province, China using lichens as biomonitors. Epilithic foliose lichen Xanthoria mandschurica was sampled from 21 sites and analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that 1) eight elements (Cd, Cr, Cu, Mo, P, Pb, Sb and Zn) are of atmospheric origin and are highly influenced by the atmospheric transportation from the North China Plain, as well as local mining activities, while 2) the remaining 22 elements are primarily of crustal origin, the concentration of which has been enhanced by local mining and quarrying activities. These results clearly validate the applicability of lichens in biomonitoring of atmospheric elemental deposition and demonstrate the spatial pattern for air pollution in the region. PMID:27089945

  12. Use of the lichen Xanthoria mandschurica in monitoring atmospheric elemental deposition in the Taihang Mountains, Hebei, China.

    PubMed

    Liu, Hua-Jie; Zhao, Liang-Cheng; Fang, Shi-Bo; Liu, Si-Wa; Hu, Jian-Sen; Wang, Lei; Liu, Xiao-Di; Wu, Qing-Feng

    2016-04-19

    Air pollution is a major concern in China. Lichens are a useful biomonitor for atmospheric elemental deposition but have rarely been used in North China. The aim of this study was to investigate the atmospheric depositions of 30 trace elements (Al, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Sc, Sm, Sr, Tb, Th, Ti, Tl, V and Zn) in a region of the Taihang Mountains, Hebei Province, China using lichens as biomonitors. Epilithic foliose lichen Xanthoria mandschurica was sampled from 21 sites and analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results show that 1) eight elements (Cd, Cr, Cu, Mo, P, Pb, Sb and Zn) are of atmospheric origin and are highly influenced by the atmospheric transportation from the North China Plain, as well as local mining activities, while 2) the remaining 22 elements are primarily of crustal origin, the concentration of which has been enhanced by local mining and quarrying activities. These results clearly validate the applicability of lichens in biomonitoring of atmospheric elemental deposition and demonstrate the spatial pattern for air pollution in the region.

  13. The oleaginous Botryococcus from the Triassic Yanchang Formation in Ordos Basin, Northwestern China: Morphology and its paleoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Ji, Li-ming; Yan, Kui; Meng, Fan-wei; Zhao, Min

    2010-05-01

    fluctuation was narrow during the Mid-Later Triassic. The ecological type of the palynological flora discovered from the Ch 7 to Ch 8 in Xifeng area is similar to that from the Fuxian Lake, with abundant Botryococcus in the Yungui Plateau of China. These findings imply that the Ordos Basin was in a lower-latitude area of temperate to subtropical climate during the Middle and Late Triassic.

  14. Impact of crop field burning and mountains on heavy haze in the North China Plain: a case study

    NASA Astrophysics Data System (ADS)

    Long, Xin; Tie, Xuexi; Cao, Junji; Huang, Rujin; Feng, Tian; Li, Nan; Zhao, Suyu; Tian, Jie; Li, Guohui; Zhang, Qiang

    2016-08-01

    With the provincial statistical data and crop field burning (CFB) activities captured by Moderate Resolution Imaging Spectroradiometer (MODIS), we extracted a detailed CFB emission inventory in the North China Plain (NCP). The WRF-CHEM model was applied to investigate the impact of CFB on air pollution during the period from 6 to 12 October 2014, corresponding to a heavy haze incident with high concentrations of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm). The WRF-CHEM model generally performed well in simulating the surface species concentrations of PM2.5, O3 and NO2 compared to the observations; in addition, it reasonably reproduced the observed temporal variations of wind speed, wind direction and planetary boundary layer height (PBLH). It was found that the CFB that occurred in southern NCP (SNCP) had a significant effect on PM2.5 concentrations locally, causing a maximum of 34 % PM2.5 increase. Under continuous southerly wind conditions, the CFB pollution plume went through a long-range transport to northern NCP (NNCP; with several mega cities, including Beijing, the capital city of China), where few CFBs occurred, resulting in a maximum of 32 % PM2.5 increase. As a result, the heavy haze in Beijing was enhanced by the CFB, which occurred in SNCP. Mountains also play significant roles in enhancing the PM2.5 pollution in NNCP through the blocking effect. The mountains blocked and redirected the airflows, causing the pollutant accumulations along the foothills of mountains. This study suggests that the prohibition of CFB should be strict not only in or around Beijing, but also on the ulterior crop growth areas of SNCP. PM2.5 emissions in SNCP should be significantly limited in order to reduce the occurrences of heavy haze events in the NNCP region.

  15. Genetic variation between Schistosoma japonicum lineages from lake and mountainous regions in China revealed by resequencing whole genomes.

    PubMed

    Yin, Mingbo; Liu, Xiao; Xu, Bin; Huang, Jian; Zheng, Qi; Yang, Zhong; Feng, Zheng; Han, Ze-Guang; Hu, Wei

    2016-09-01

    Schistosoma infection is a major cause of morbidity and mortality worldwide. Schistosomiasis japonica is endemic in mainland China along the Yangtze River, typically distributed in two geographical categories of lake and mountainous regions. Study on schistosome genetic diversity is of interest in respect of understanding parasite biology and transmission, and formulating control strategy. Certain genetic variations may be associated with adaptations to different ecological habitats. The aim of this study is to gain insight into Schistosoma japonicum genetic variation, evolutionary origin and associated causes of different geographic lineages through examining homozygous Single Nucleotide Polymorphisms (SNPs) based on resequenced genome data. We collected S. japonicum samples from four sites, three in the lake regions (LR) of mid-east (Guichi and Tonglin in Anhui province, Laogang in Hunan province) and one in mountainous region (MR) (Xichang in Sichuan province) of south-west of China, resequenced their genomes using Next Generation Sequencing (NGS) technology, and made use of the available database of S. japonicum draft genomic sequence as a reference in genome mapping. A total of 14,575 SNPs from 2059 genes were identified in the four lineages. Phylogenetic analysis confirmed significant genetic variation exhibited between the different geographical lineages, and further revealed that the MR Xichang lineage is phylogenetically closer to LR Guich lineage than to other two LR lineages, and the MR lineage might be evolved from LR lineages. More than two thirds of detected SNPs were nonsynonymous; functional annotation of the SNP-containing genes showed that they are involved mainly in biological processes such as signaling and response to stimuli. Notably, unique nonsynonymous SNP variations were detected in 66 genes of MR lineage, inferring possible genetic adaption to mountainous ecological condition. PMID:27207135

  16. Zircon U-Pb geochronology and geochemistry of two episodes of granitoids from the northwestern Zhejiang Province, SE China: Implication for magmatic evolution and tectonic transition

    NASA Astrophysics Data System (ADS)

    Li, Zilong; Zhou, Jing; Mao, Jianren; Santosh, M.; Yu, Minggang; Li, Yinqi; Hu, Yizhou; Langmuir, Charles H.; Chen, Zhongxing; Cai, Xiongxiang; Hu, Yanhua

    2013-10-01

    Granitoids (175-80 Ma) representing a prominent Yanshanian (Jurassic to Cretaceous) magmatic event in South China widely intrude the Precambrian crystalline basement and Paleozoic strata. Here we report zircon U-Pb age data, geochemical characteristics and Sr-Nd isotopes of the Late Jurassic and Early Cretaceous granitoids from the northwestern Zhejiang Province (ZXB) of southeastern China. Our results reveal two distinct episodes for the Yanshanian magmatism. The Jiemeng and Datongkeng granodiorites formed at 148.6 ± 1.1 Ma, whereas the Huangshitan, Jiuligang and Ruhong aluminous A-type granites were generated between 129.0 ± 0.6 Ma and 126.1 ± 1.1 Ma. The two magmatic phases represent a tectonic transition from an active continental margin to post-orogenic setting during the Late Jurassic (ca. 150 Ma) to Early Cretaceous (ca. 128 Ma). Geochemically, these intrusions are granodioritic to granitic in composition and show an affinity of S-type and A-type granitoids, respectively. The S-type granodiorites of Jiemeng and Datongkeng are characterized by moderate SiO2 (65.0-69.6 wt.%), high K2O + Na2O (5.0-7.6 wt.%), K2O/Na2O (1.2-1.5), Zr (31-109 ppm), Sr (71-190 ppm) and high field strength elements, low to intermediate Mg#, and moderate Nb depletion. The A-type granites of Huangshitan, Jiuligang and Ruhong are characterized by high SiO2 (72.7-77.2 wt.%), K2O + Na2O (6.9-8.8 wt.%), K2O/Na2O (1.3-2.1), FeT/(FeT + Mg), Ga (17-29 ppm, > 20 ppm commonly), Zr (96-197 ppm) and Sr (8-45 ppm) with slight Nb depletion. The S-type granodiorites have higher Mg#, A/NK, Sr, Sr/Ba, Sr/Y, (La/Yb)N, and LREE/HREE, and lower SiO2, K2O + Na2O, Ga and Zr with weak negative Eu anomalies compared to those of the A-type granites with negative Eu anomalies. All these rocks show Y/Nb ratios > 1.2, high initial 87Sr/86Sr (ISr) ratios and low ɛNd(t), and are depleted in Nb, Ti and Sr, indicating crustal origin with subduction zone signatures. We suggested that the ZXB S-type granitic

  17. The role of anthropogenic and natural factors in shaping the geochemical evolution of groundwater in the Subei Lake basin, Ordos energy base, Northwestern China.

    PubMed

    Liu, Fei; Song, Xianfang; Yang, Lihu; Han, Dongmei; Zhang, Yinghua; Ma, Ying; Bu, Hongmei

    2015-12-15

    Groundwater resources are increasingly exploited for industrial and agricultural purposes in many arid regions globally, it is urgent to gain the impact of the enhanced anthropogenic pressure on the groundwater chemistry. The aim of this study was to acquire a comprehensive understanding of the evolution of groundwater chemistry and to identify the impact of natural and anthropogenic factors on the groundwater chemistry in the Subei Lake basin, Northwestern China. A total of 153 groundwater samples were collected and major ions were measured during the three campaigns (August and December 2013, May 2014). At present, the major hydrochemical facies in unconfined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Na-HCO3, Ca-Mg-SO4 and Na-SO4-Cl types, while the main hydrochemical facies in confined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Ca-HCO3 and Na-HCO3 types. Relatively greater seasonal variation can be observed in the chemical constituents of confined groundwater than that of unconfined groundwater. Rock weathering predominates the evolution of groundwater chemistry in conjunction with the cation exchange, and the dissolution/precipitation of gypsum, halite, feldspar, calcite and dolomite are responsible for the chemical constituents of groundwater. Anthropogenic activities can be classified as: (1) groundwater overexploitation; (2) excessive application of fertilizers in agricultural areas. Due to intensive groundwater pumping, the accelerated groundwater mineralization resulted in the local changes in hydrochemical facies of unconfined groundwater, while the strong mixture, especially a large influx of downward leakage from the unconfined aquifer into the confined aquifer, played a vital role in the fundamental variation of hydrochemical facies in confined aquifer. The nitrate contamination is mainly controlled by the local hydrogeological settings coupled with the traditional flood irrigation. The deeper insight into geochemical evolution of

  18. News insights of the hydrology of the Northwestern subtropical Pacific Ocean from ɛNd investigations of the South China Sea sediments

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Christophe, C.; Liu, Z.; Douville, E.; Dubois-Dauphin, Q.

    2015-12-01

    Seawater Nd isotopic composition (ɛNd) extracted from planktonic foraminifera G. ruber have been investigated on core MD05-2904 located on the northwestern margin of the South China Sea (SCS) at 2000 m water depth to reconstruct hydrological variations since the Last Glacial Maximum (LGM) of the western subtropical North Pacific that still poorly documented. For the last 25 kyr, ɛNd values obtained on foraminifera present large range from -4 to -6.7 suggesting large changes in the contribution of the NPDW (ɛNd = -4) and the UCDW (ɛNd -6 to -8) in the western Pacific. The glacial ɛNd values (~ -6.5) are interestingly similar to those obtained in the South Atlantic and in the Indian Ocean during the LGM and indicate a strong northward propagation of the Southern Sourced Water (SSW) in the subtropical western North Pacific. During the deglaciation, ɛNd records indicate a relatively decreased proportion of the SSW in the deep-water component of the western subtropical Pacific interrupted by two negative excursions of the ɛNd implying higher proportion of SSW during the time intervals 17 - 15 cal kyr BP and 10 - 8 cal kyr BP coeval to the Heinrich Statial 1 (HS1) and the early Holocene. The seawater ɛNd record is also well correlated to δ13C record obtained on benthic foraminifera Cibicides wuellerstorfi of the SCS and Southern Ocean confirming that ɛNd record reflect global circulation changes. The negative shifts centered on the Heinrich Statial 1 (HS1) is coeval with an enhanced upwelling in the Southern Ocean associated to pole wards shifts of the southern westerly inducing a enhanced formation of the SSW that propagate to the subtropical western Pacific. The negative excursion of the ɛNd during the Early Holocene (~10 - 8 cal kyr BP) indicate a relatively higher proportion of the SSW that could be associated to a higher production of the SSW as it was already recently observed in the South Atlantic and/or a possible reduction of the NPIW in the North

  19. [Long-Term Different Fertilizations Changed the Chemical and Spectrum Characteristics of DOM of the Irrigation-Desert Soil in North-Western China].

    PubMed

    Chang, Dan-na; Cao, Wei-dong; Bag, Xing-guo; Bai, Jin-shun; Zhang, Jiu-dong; Lu, Bing-lin; Gao, Song-juan; Zeng, Nao-hua; Wang, Xue-cui; Katsuyoshi, Shimizu

    2016-01-01

    By using Ultraviolet-visible Spectrometry, Fourier Transform Infrared Spectrometer and Elemental Analyzer, spectrum and chemical characteristics of soil DOM affected by long-term different fertilizations were investigated in irrigation-desert soil in North-western China based on an experiment started from 1988. Four different fertilization treatments were included, i. e., organic fertilizer (OF), green manure (GM), chemical fertilizer (CF) and a control of no fertilization (CK). The results showed that fertilization could increase the contents of DOM. Compared to CK, the treatments of OF, GM, CF increased the dissolved organic carbon (DOC) by 37%, 29%, 16%; increased the dissolved nitrogen (DON) by 334%, 257%, 182%; increased the total carbohydrate (TCs) by 90%, 25%, 2%; and increased the total organic acids (TOAs) by 195%, 116%, 58%; respectively. Furthermore, DOC, DON, TCs, and TOAs in the OF treatment were significantly higher than those in CK, they were also significantly higher in the GM and CF treatments except for TCs. The ultraviolet-visible analysis showed that fertilizations enhanced the SUVA(254), SUVA(260), SUVA(272) and SUVA(280) of DOM, indicating that fertilizations increased the aromatic and hydrophobic percentage, humification degree, and average molecular weight, and thus resulting in more stability of DOM. Same trends were showed for all the 4 ultraviolet spectrum absorption values in different fertilizations, i. e., the strongest effect was found in the OF treatment, and then was the GM treatment and CF treatment successively. From the results by the Fourier Transform Infrared Spectrometry, the characteristic peak of aromatic in the OF treatment was observed shifting from 1 625 to 1 649 cm(-1), which was close to the characteristic peak of humin, suggesting that the aromaticity of DOM in the OF treatment was higher than the other treatments. The characteristic peaks of C-O at 1 260-1 000 cm(-1) belonging to sugar, alcohol, and carboxylic acid

  20. Rock magnetic properties of an 8-Ma terrigenous succession from the northern Tian Shan foreland basin, northwestern China and aridification of the Asian inland

    NASA Astrophysics Data System (ADS)

    Lu, H.; Zhang, W.; Li, Y.; Dong, C.; Zhang, T.; Zhou, Z.; Zheng, X.

    2013-12-01

    The Asian inland is characterized by exceptional topographic relief and widespread deserts and semi-deserts. Its environmental evolution during the late Cenozoic is featured by two processes: (1) growth and uplift of the Tibetan Plateau (including the hinterland to the north) and (2) stepwise development of dry climate. Many previous investigations have attempted to reconstruct the process of plateau uplift or constrain the aridification history. The relative role of the Tibetan Plateau uplift and Cenozoic global cooling in the aridification process of the Asian interior, however, remains an issue of debate. More detailed paleoclimatic/tectonic investigations over a broad area should be beneficial to better answer this question. In the northern Tian Shan foreland basin, northwestern China was deposited thick Cenozoic terrigenous succession, which is crucial for paleoenvironmental reconstruction of the Asian interior. Here we present a detailed rock magnetic investigation on 245 samples from the ~1,200-m-thick Neogene Taxi He section with a magnetostratigraphic age span of ca. 8.0 to 2.0 Ma in the northern Tian Shan foreland basin. Our rock magnetic results indicate that the significant variations in composition, concentration and grain size of magnetic minerals occurred at ca. 6.0, 3.7 and 2.7 Ma. The comparable compositions of rare earth elements (REEs) throughout the Neogene Taxi He section suggest no significant modification of the source materials during the interval between ca. 8.0 and 2.0 Ma, and thus sediment provenance is not regarded as responsible for these observed variations in rock magnetic properties. Our further analyses show that the variations in magnetic property of the Neogene Taxi He deposits are casually linked mainly with lithofacies transition due to range encroachment into foreland basin as well as climate aridification. Identified enhancement of aridification was chronologically constrained at ca. 6.0 and 2.7 Ma based on the variations of

  1. Petrogenesis of gold-mineralized magmatic rocks of the Taerbieke area, northwestern Tianshan (western China): Constraints from geochronology, geochemistry and Sr-Nd-Pb-Hf isotopic compositions

    NASA Astrophysics Data System (ADS)

    Tang, Gong-Jian; Wang, Qiang; Wyman, Derek A.; Sun, Min; Zhao, Zhen-Hua; Jiang, Zi-Qi

    2013-09-01

    Many Late Paleozoic Cu-Au-Mo deposits occur in the Central Asian Orogenic Belt (CAOB). However, their tectonic settings and associated geodynamic processes have been disputed. This study provides age, petrologic and geochemical data for andesites and granitic porphyries of the Taerbieke gold deposit from the Tulasu Basin, in the northwestern Tianshan Orogenic Belt (western China). LA-ICP-MS zircon U-Pb dating indicates that the granitic porphyries have an Early Carboniferous crystallization age (349 ± 2 Ma) that is broadly contemporaneous with the eruption age (347 ± 2 Ma) of the andesites. The andesites have a restricted range of SiO2 (58.94-63.85 wt.%) contents, but relatively high Al2O3 (15.39-16.65 wt.%) and MgO (2.51-6.59 wt.%) contents, coupled with high Mg# (57-69) values. Geochemically, they are comparable to Cenozoic sanukites in the Setouchi Volcanic Belt, SW Japan. Compared with the andesites, the granitic porphyries have relatively high SiO2 (72.68-75.32 wt.%) contents, but lower Al2O3 (12.94-13.84 wt.%) and MgO (0.10-0.33 wt.%) contents, coupled with lower Mg# (9-21) values. The andesites and granitic porphyries are enriched in both large ion lithophile and light rare earth elements, but depleted in high field strength elements, similar to those of typical arc magmatic rocks. They also have similar Nd-Hf-Pb isotope compositions: ɛNd(t) (+0.48 to +4.06 and -0.27 to +2.97) and zircons ɛHf(t) (+3.4 to +8.0 and -1.7 to +8.2) values and high (206Pb/204Pb)i (18.066-18.158 and 17.998-18.055). We suggest that the Taerbieke high-Mg andesitic magmas were generated by the interaction between mantle wedge peridotites and subducted oceanic sediment-derived melts with minor basaltic oceanic crust-derived melts, and that the magmas then fractionated to produce the more felsic members (i.e., the Taerbieke granitic porphyries) during late-stage evolution. Taking into account the Carboniferous magmatic record from the western Tianshan Orogenic Belt, we suggest that

  2. Geochemical characteristics of the Triassic Tethys-turbidites in northwestern Sichuan, China: Implications for provenance and interpretation of the tectonic setting

    NASA Astrophysics Data System (ADS)

    Gu, X. X.

    1994-11-01

    The Triassic Tethys graywacke-slate turbidites in the northwestern Sichuan, China have been analysed for major and trace elements and petrographically studied. Compared to Phanerozoic turbidites, the turbidites in this study are quartz-intermediate (average 55%) in composition and are characterized geochemically by their moderate Fe 2O ∗3 + MgO (9.28 ± 2.84%), TiO 2 (0.72 ± 0.17%) contents and Al 2O 3/SiO 2 (0.25 ± 0.10) ratios; moderate abundances of ferromagnesian trace elements ( Co = 15 ± 8 ppm, Cr = 113 ± 72 ppm, Ni = 14 + 9 ppm, Sc = 12 ± 4 ppm, etc.); and moderate contents of incompatible elements, such as Th (11 ± 3 ppm), U (3 ± 0.7 ppm), Zr (170 ± 64 ppm), Hf (4 ± 1 ppm) and total REEs (159 ± 33 ppm). In general, the slates show systematically higher Fe 2O ∗3 + MgO, Sc, Co and Eu/Eu∗, but lower solLa/Sc and Th/Sc than the associated graywackes, suggesting that various provenance components may separate into different grain-size fractions during sedimentary sorting processes, that is, the more mafic materials tended to incorporate into the sedimentary record for the clay-size fraction. Framework modes and geochemical data indicate that the turbidites were mainly derived from a recycled orogenic provenance characterized chiefly by sedimentary-metasedimentary rocks and granite-gneisses, similar to the upper continental crust, but with a variable admixture of continental island arc volcanic components. Flysch deposition took place in a back arc basin situated between an active continental margin (the Kunlun-Qinling fold belt) and a continental island arc (the Yidun island arc). Weathering conditions in the source area significantly influenced the composition and distribution of elements in the sediments. With the elapse of time during sedimentation, the degree of chemical weathering in the provenance became intense while the tectonic activity decreased gradually.

  3. [Ecological characteristics of preferred habitat of reindeer of Daxing'an Mountain forest area Northeast China in summer].

    PubMed

    Wang, Peng; Meng, Fan-Lu; Zeng, Zhi; Wang, Wei-Ping; Sheng, Yan; Feng, Jin-Chao; Zhou, Yi-Jun; Xue, Da-Yuan; Meng, Xiu-Xiang

    2014-09-01

    In July and August of 2012 and 2013, habitat selection and use patterns of reindeer were studied using both line and strip-transect surveys. Twenty-three habitat factors were measured and compared in known reindeer range areas in northwestern China. A total of 72 sampling sites were designated as being used by reindeer, and 162 sites were designated as unused control plots. The results indicated that, compared to the non-used habitat plots, reindeer selected summer habitats with higher values in altitude (26.9 ± 0.8 m), arbor canopy (17.9% ± 2.4%), arbor DBH (35.5 ± 2.1 cm), arbor height (8.2 ± 0.5 m), arbor density (6.9 ± 0.5 ind · 400 m(-2)) and stump quan- tity (1.3 ± 0.2 ind · 400 m(-2)), and with a lower shrub height (54.2 ± 2.0 cm). Moreover, reindeer also selected habitats at intermediate positions of intermediate slope gradient, which provided good water accessibility, more distance from human disturbance and herder influence, but bad concealment and lee condition. Results of the principal component analysis showed that the disturbance intensity (i. e. residential dispersion, anthropogenic-disturbance dispersion), arbor characteristics (arbor height and arbor density, arbor DBH and arbor canopy), geography characteristics (i. e. slope position, slope aspect and soil moisture), food abundance (ground-plant cover and shrub cover), openness (concealment and lee condition) and slope gradient were the most important factors influencing the habitat selection of reindeer in summer. In summary, the summer habitat selection of reindeer is a multidimensional process, through which reindeer adapt according to their ecological needs of food resources, safety and anti-predation. Furthermore, the pattern of habitat selection of reindeer showed that reindeer in China has not yet been domesticated, and reindeer populations and their core habitats should be conserved from intensive disturbance.

  4. [Ecological characteristics of preferred habitat of reindeer of Daxing'an Mountain forest area Northeast China in summer].

    PubMed

    Wang, Peng; Meng, Fan-Lu; Zeng, Zhi; Wang, Wei-Ping; Sheng, Yan; Feng, Jin-Chao; Zhou, Yi-Jun; Xue, Da-Yuan; Meng, Xiu-Xiang

    2014-09-01

    In July and August of 2012 and 2013, habitat selection and use patterns of reindeer were studied using both line and strip-transect surveys. Twenty-three habitat factors were measured and compared in known reindeer range areas in northwestern China. A total of 72 sampling sites were designated as being used by reindeer, and 162 sites were designated as unused control plots. The results indicated that, compared to the non-used habitat plots, reindeer selected summer habitats with higher values in altitude (26.9 ± 0.8 m), arbor canopy (17.9% ± 2.4%), arbor DBH (35.5 ± 2.1 cm), arbor height (8.2 ± 0.5 m), arbor density (6.9 ± 0.5 ind · 400 m(-2)) and stump quan- tity (1.3 ± 0.2 ind · 400 m(-2)), and with a lower shrub height (54.2 ± 2.0 cm). Moreover, reindeer also selected habitats at intermediate positions of intermediate slope gradient, which provided good water accessibility, more distance from human disturbance and herder influence, but bad concealment and lee condition. Results of the principal component analysis showed that the disturbance intensity (i. e. residential dispersion, anthropogenic-disturbance dispersion), arbor characteristics (arbor height and arbor density, arbor DBH and arbor canopy), geography characteristics (i. e. slope position, slope aspect and soil moisture), food abundance (ground-plant cover and shrub cover), openness (concealment and lee condition) and slope gradient were the most important factors influencing the habitat selection of reindeer in summer. In summary, the summer habitat selection of reindeer is a multidimensional process, through which reindeer adapt according to their ecological needs of food resources, safety and anti-predation. Furthermore, the pattern of habitat selection of reindeer showed that reindeer in China has not yet been domesticated, and reindeer populations and their core habitats should be conserved from intensive disturbance. PMID:25757301

  5. [Climate-growth relationships of Picea koraiensis and causes of its recent decline in Xiaoxing' an Mountains, China].

    PubMed

    Yao, Qi-chao; Wang, Xiao-chun; Xiao, Xing-wei

    2015-07-01

    Two tree-ring width chronologies of Picea koraiensis at two altitudes in Fenglin National Nature Reserve of Xiaoxing'an Mountains, China were developed by using dendrochronological methods. To identify main limiting factors of P. koraiensis radial growth at the two altitudes, the relationships between the chronologies and local temperature, precipitation, Palmer drought severity index (PDSI), and large-scale climatic factors were investigated. Meanwhile, the reasons of P. koraiensis growth decline in recent years were also explored. Results showed that radial growth of P. koraiensis in Xiaoxing'an Mountains was mainly limited by temperatures, especially by the minimum temperature in growing season, while the limiting effect of precipitation was relatively weak. Climate responses of P. koraiensis growth at the different altitudes showed significant differences. Radial growths of P. koraiensis at the low altitude were positively correlated with precipitation in the current growth season (June-September) and whole year, and negatively correlated with soil temperatures at different depths, especially at 80 cm depth in growing season. Meanwhile, it was signi-ficantly positively correlated with PDSI in growing season. However, the relationships between radial growth of P. koraiensis at the high altitude and precipitation, air and soil temperatures, and PDSI were not significant as that at the low altitude. Growth decline of P. koraiensis in Xiaoxing'an Mountains could be related to the phase changes in Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) and the significant global warming since 1980. The coupling effects of the above changes might result in increased soil evaporation and exacerbated warming and drying phenomena, consequently causing the growth decline of P. koraiensis at the low altitude. PMID:26710617

  6. Nitrogen deposition but not climate warming promotes Deyeuxia angustifolia encroachment in alpine tundra of the Changbai Mountains, Northeast China.

    PubMed

    Zong, Shengwei; Jin, Yinghua; Xu, Jiawei; Wu, Zhengfang; He, Hongshi; Du, Haibo; Wang, Lei

    2016-02-15

    Vegetation in the alpine tundra area of the Changbai Mountains, one of two alpine tundra areas in China, has undergone great changes in recent decades. The aggressive herb species Deyeuxia angustifolia (Komarov) Y. L. Chang, a narrow-leaf small reed, was currently encroaching upon the alpine landscape and threatening tundra biota. The alpine tundra of the Changbai Mountains has been experiencing a warmer climate and receiving a high load of atmospheric nitrogen deposition. In this study, we aimed to assess the respective roles of climate warming and atmospheric nitrogen deposition in promoting the upward encroachment of D. angustifolia. We conducted experiments for three years to examine the response of D. angustifolia and a native alpine shrub, Rhododendron chrysanthum, to the conditions in which temperature and nitrogen were increased. Treatments consisting of temperature increase, nitrogen addition, temperature increase combined with nitrogen addition, and controls were conducted on the D. angustifolia communities with three encroachment levels (low, medium, and high levels). Results showed that 1) D. angustifolia grew in response to added nutrients but did not grow well when temperature increased. R. chrysanthum showed negligible responses to the simulated environmental changes. 2) Compared to R. chrysanthum, D. angustifolia could effectively occupy the above-ground space by increasing tillers and growing rapidly by efficiently using nitrogen. The difference in nitrogen uptake abilities between the two species contributed to expansion of D. angustifolia. 3) D. angustifolia encroachment could deeply change the biodiversity of tundra vegetation and may eventually result in the replacement of native biota, especially with nitrogen addition. Our research indicated that nutrient perturbation may be more important than temperature perturbation in promoting D. angustifolia encroachment upon the nutrient- and species-poor alpine tundra ecosystem in the Changbai

  7. [Climate-growth relationships of Picea koraiensis and causes of its recent decline in Xiaoxing' an Mountains, China].

    PubMed

    Yao, Qi-chao; Wang, Xiao-chun; Xiao, Xing-wei

    2015-07-01

    Two tree-ring width chronologies of Picea koraiensis at two altitudes in Fenglin National Nature Reserve of Xiaoxing'an Mountains, China were developed by using dendrochronological methods. To identify main limiting factors of P. koraiensis radial growth at the two altitudes, the relationships between the chronologies and local temperature, precipitation, Palmer drought severity index (PDSI), and large-scale climatic factors were investigated. Meanwhile, the reasons of P. koraiensis growth decline in recent years were also explored. Results showed that radial growth of P. koraiensis in Xiaoxing'an Mountains was mainly limited by temperatures, especially by the minimum temperature in growing season, while the limiting effect of precipitation was relatively weak. Climate responses of P. koraiensis growth at the different altitudes showed significant differences. Radial growths of P. koraiensis at the low altitude were positively correlated with precipitation in the current growth season (June-September) and whole year, and negatively correlated with soil temperatures at different depths, especially at 80 cm depth in growing season. Meanwhile, it was signi-ficantly positively correlated with PDSI in growing season. However, the relationships between radial growth of P. koraiensis at the high altitude and precipitation, air and soil temperatures, and PDSI were not significant as that at the low altitude. Growth decline of P. koraiensis in Xiaoxing'an Mountains could be related to the phase changes in Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) and the significant global warming since 1980. The coupling effects of the above changes might result in increased soil evaporation and exacerbated warming and drying phenomena, consequently causing the growth decline of P. koraiensis at the low altitude.

  8. [Influence of biomass burning in Central Asia on nitrate concentrations in Urumqi Glacier No. 1, eastern Tianshan Mountains, China].

    PubMed

    Wang, Sheng-Jie; Zhang, Ming-Jun; Wang, Fei-Teng; Li, Zhong-Qin

    2011-02-01

    Influence of biomass burning in Kazakhstan on nitrate concentrations in eastern Tianshan Mountains was studied. 52 samples of surface snow and snow pits were collected from Glacier No. 1 at the headwater of Urumqi River in eastern Tianshan Mountains, China. Nitrate concentrations in these samples were measured and atmospheric transmission was reconstructed with HYSPLIT air trajectory model. The objectives of this study were to identify the relationship between steppes fire and nitrate concentration in snow, and develop deposition process of nitrate caused by biomass burning in alpine glacier at high altitude. Results indicated that nitrate in surface snow could be regarded as a subsidiary indicator of biomass burning for long distance. Correlations for NO3- and K+ were 0.74 from mid September to late October 2002, which was obviously higher than mean concentration. It took 2-6 days from fire spots in Kazakhstan to sampling site. Whether the information in air mass with biomass burning products can be recorded or not, was mostly depend on local temperature and precipitation. Eluviation process was prominent at Glacier No. 1 in wet season, so postdepositional effect should be considered in paleoclimate reconstruction by ice core.

  9. DNA barcoding reveals a mysterious high species diversity of conifer-feeding aphids in the mountains of southwest China.

    PubMed

    Chen, Rui; Jiang, Li-Yun; Chen, Jing; Qiao, Ge-Xia

    2016-02-03

    The mountains of southwest China are one of the hot spots of biodiversity in the world. However, the high-altitude fauna that inhabit these mountains remain a mystery. In this study, the species diversity of the aphids of the genus Cinara from the high-altitude coniferous forests was first assessed, and then the processes and the mechanisms of speciation were discussed. Three hundreds and four aphid samples that contained 3040 individuals were collected during fourteen field surveys. The molecular clusters derived from the DNA barcodes were used to explore the species diversity. Notably, the aphid alpha-diversity was high, with as many as 94 candidate species, and furthermore, 86.2% of the species collected had not been previously recorded. The centers of aphid species richness corresponded to the distributional pattern of the diversity of the host conifer plant species. The divergence time revealed that following the uplift of the Qinghai-Tibetan Plateau during the Pleistocene, the changes in the climate, ecology and host habitats were likely the most important factors that drove the rapid process of evolutionary radiation in the aphids. Our findings revealed the high species diversity of the aphids with DNA barcoding.

  10. DNA barcoding reveals a mysterious high species diversity of conifer-feeding aphids in the mountains of southwest China

    PubMed Central

    Chen, Rui; Jiang, Li-Yun; Chen, Jing; Qiao, Ge-Xia

    2016-01-01

    The mountains of southwest China are one of the hot spots of biodiversity in the world. However, the high-altitude fauna that inhabit these mountains remain a mystery. In this study, the species diversity of the aphids of the genus Cinara from the high-altitude coniferous forests was first assessed, and then the processes and the mechanisms of speciation were discussed. Three hundreds and four aphid samples that contained 3040 individuals were collected during fourteen field surveys. The molecular clusters derived from the DNA barcodes were used to explore the species diversity. Notably, the aphid alpha-diversity was high, with as many as 94 candidate species, and furthermore, 86.2% of the species collected had not been previously recorded. The centers of aphid species richness corresponded to the distributional pattern of the diversity of the host conifer plant species. The divergence time revealed that following the uplift of the Qinghai-Tibetan Plateau during the Pleistocene, the changes in the climate, ecology and host habitats were likely the most important factors that drove the rapid process of evolutionary radiation in the aphids. Our findings revealed the high species diversity of the aphids with DNA barcoding. PMID:26838797

  11. Dissolved Organic Carbon in Headwater Streams and Riparian Soil Organic Carbon along an Altitudinal Gradient in the Wuyi Mountains, China

    PubMed Central

    Huang, Wei; McDowell, William H.; Zou, Xiaoming; Ruan, Honghua; Wang, Jiashe; Li, Liguang

    2013-01-01

    Stream water dissolved organic carbon (DOC) correlates positively with soil organic carbon (SOC) in many biomes. Does this relationship hold in a small geographic region when variations of temperature, precipitation and vegetation are driven by a significant altitudinal gradient? We examined the spatial connectivity between concentrations of DOC in headwater stream and contents of riparian SOC and water-soluble soil organic carbon (WSOC), riparian soil C:N ratio, and temperature in four vegetation types along an altitudinal gradient in the Wuyi Mountains, China. Our analyses showed that annual mean concentrations of headwater stream DOC were lower in alpine meadow (AM) than in subtropical evergreen broadleaf forest (EBF), coniferous forest (CF), and subalpine dwarf forest (SDF). Headwater stream DOC concentrations were negatively correlated with riparian SOC as well as WSOC contents, and were unrelated to riparian soil C:N ratio. Our findings suggest that DOC concentrations in headwater streams are affected by different factors at regional and local scales. The dilution effect of higher precipitation and adsorption of soil DOC to higher soil clay plus silt content at higher elevation may play an important role in causing lower DOC concentrations in AM stream of the Wuyi Mountains. Our results suggest that upscaling and downscaling of the drivers of DOC export from forested watersheds when exploring the response of carbon flux to climatic change or other drivers must done with caution. PMID:24265737

  12. Dissolved organic carbon in headwater streams and riparian soil organic carbon along an altitudinal gradient in the Wuyi Mountains, China.

    PubMed

    Huang, Wei; McDowell, William H; Zou, Xiaoming; Ruan, Honghua; Wang, Jiashe; Li, Liguang

    2013-01-01

    Stream water dissolved organic carbon (DOC) correlates positively with soil organic carbon (SOC) in many biomes. Does this relationship hold in a small geographic region when variations of temperature, precipitation and vegetation are driven by a significant altitudinal gradient? We examined the spatial connectivity between concentrations of DOC in headwater stream and contents of riparian SOC and water-soluble soil organic carbon (WSOC), riparian soil C:N ratio, and temperature in four vegetation types along an altitudinal gradient in the Wuyi Mountains, China. Our analyses showed that annual mean concentrations of headwater stream DOC were lower in alpine meadow (AM) than in subtropical evergreen broadleaf forest (EBF), coniferous forest (CF), and subalpine dwarf forest (SDF). Headwater stream DOC concentrations were negatively correlated with riparian SOC as well as WSOC contents, and were unrelated to riparian soil C:N ratio. Our findings suggest that DOC concentrations in headwater streams are affected by different factors at regional and local scales. The dilution effect of higher precipitation and adsorption of soil DOC to higher soil clay plus silt content at higher elevation may play an important role in causing lower DOC concentrations in AM stream of the Wuyi Mountains. Our results suggest that upscaling and downscaling of the drivers of DOC export from forested watersheds when exploring the response of carbon flux to climatic change or other drivers must done with caution.

  13. [Soil organic carbon storage in different aged Larix gmelinii plantations in Great Xing' an Mountains of Northeast China].

    PubMed

    Qi, Guang; Wang, Qing-Li; Wang, Xin-Chuang; Yu, Da-Pao; Zhou, Li; Zhou, Wang-Ming; Peng, Shun-Lei; Dai, Li-Min

    2013-01-01

    A sampling plot investigation was conducted to study the soil organic carbon (SOC) storage in 0-40 cm layer in 10-, 15-, 26- and 61 years old Larix gmelinii plantations in Great Xing' an Mountains of Northeast China as well as the temporal variation pattern of the SOC source/sink during the plantation management after the clear cutting of primary L. gmelinii forest. With the increasing age of the plantations, the SOC storage increased after an initial decrease, and the inflection point was at a stand age between 15- and 26-years old. Compared with that of primary forest, the SOC storage of the plantations played a role of carbon source at early stage (10-26 years old), but gradually transformed into carbon sink then, with a SOC storage of 158.91 t x hm(-2) in 61-year-old plantation. The SOC storage of the plantations increased with soil depth initially, but was higher in upper soil layer than in deeper soil layer after the stand age being 26, which implied that human disturbance had strong effects on the vertical distribution of SOC. It was considered that the appropriate cutting age for the L. gmelinii plantations in Great Xing' an Mountains could be at least 60 years old.

  14. Population structure and spatial pattern of main tree species in secondary Betula platyphylla forest in Ziwuling Mountains, China.

    PubMed

    Kang, Di; Guo, Yaoxin; Ren, Chengjie; Zhao, Fazhu; Feng, Yongzhong; Han, Xinhui; Yang, Gaihe

    2014-01-01

    This study investigated a typical secondary Betula platyphylla forest in the Ziwuling Mountains, Loess Plateau, China. In the sample plot, the DBH (diameter at breast height) class structure of B. platyphylla was bimodal. Individuals with small and large DBH values were abundant. The DBH structures of Quercus wutaishanica and Pinus tabulaeformis were close to that of the logistic model, thus suggesting the increasing population of these species. B. platyphylla and Populus davidiana showed random spatial distributions at almost all scales. However, Q. wutaishanica and P. tabulaeformis were significantly clumped at small scales. B. platyphylla had a negative spatial relation with Q. wutaishanica at small spatial scales. P. tabulaeformis and Q. wutaishanica showed negative spatial correlations at small scales, but they had positive correlations at large scales. These results suggest that P. tabulaeformis and Q. wutaishanica shared habitat preferences at these scales. In the future, the secondary B. platyphylla forest in the Ziwuling Mountains in the Loess Plateau will probably change into a multi-species mixed forest (Quercus-Pinus mixed forest). Assisted restoration strategies must be employed to improve the regeneration dynamics of the forest in the long term. PMID:25362993

  15. Population structure of the golden snub-nosed monkey Rhinopithecus roxellana in the Qinling Mountains, central China.

    PubMed

    Huang, Kang; Guo, Songtao; Cushman, Samuel A; Dunn, Derek W; Qi, Xiaoguang; Hou, Rong; Zhang, Jing; Li, Qi; Zhang, Qiang; Shi, Zhen; Zhang, Kan; Li, Baoguo

    2016-09-01

    Environmental barriers and habitat fragmentation can restrict gene flow, leading to genetic divergence among animal populations. The golden snub-nosed monkey, Rhinopithecus roxellana, is endemic to China, and ranges across 4 provinces. However, over the past 40 years its populations have become fragmented. We investigated the genetic diversity, demographic history and population structure of R. roxellana in 5 reserves in one of its strongholds, the Qinling Mountain forests of Shaanxi. We collected genetic material from 11 monkey bands (a group of individuals containing multiple 1-male units) with a total of 428 samples genotyped at 20 microsatellite loci. Allelic richness and heterozygosity suggested a relatively high level of intra-band genetic diversity. We found no evidence of any genetic bottleneck in these R. roxellana populations. AMOVA and Bayesian cluster analysis revealed that R. roxellana in the 5 reserves are highly structured and form at least 3 distinct subpopulations. These subpopulations concur with major topographical features in the study area, such as mountain ridges, suggesting that dispersal of R. roxellana may be restricted by geographical barriers. PMID:27059276

  16. Lead isotopic composition of insoluble particles from widespread mountain glaciers in western China: Natural vs. anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Yu, Guangming; Xu, Jianzhong; Kang, Shichang; Zhang, Qianggong; Huang, Jie; Ren, Qian; Ren, Jiawen; Qin, Dahe

    2013-08-01

    Stable lead (Pb) isotopic fingerprints provide opportunities to trace natural and anthropogenic Pb sources in the environment. In order to evaluate Pb deposition from different sources over mountainous areas of western China, Pb isotopic compositions were characterized from modern aeolian dust in 15 snowpit samples collected from 13 typical mountain glaciers between 2008 and 2010. Most of the snowpits sampled cover more than a whole year of accumulation and overlap with each other on deposition date. Pb isotopic variability among all the samples is small, varying in the range of 18.1399-18.9199 for 206Pb/204Pb, 15.5979-15.8743 for 207Pb/204Pb, 38.2272-39.9453 for 208Pb/204Pb, 1.1605-1.2009 for 206Pb/207Pb and 2.4433-2.5182 for 208Pb/207Pb. Three isotopic plots of the different Pb isotope ratios (207Pb/204Pb vs. 206Pb/204Pb, 208Pb/204Pb vs. 206Pb/204Pb, and 208Pb/207Pb vs. 206Pb/207Pb) in all the samples show identical geographic trends, with more radiogenic in the south and less in the north. This trend is consistent with the distribution of natural dust sources and supports the interpretation of a regional/local source for insoluble particles (IP) to snow/glaciers in this region. Comparison with the Pb isotope results from potential dust sources, however, it shows that the Pb isotopic compositions of IP samples in snow samples are relatively less radiogenic. Parts of these less-radiogenic Pb isotopes are comparable with the ice core results during recent decades, which are shown to be influenced by anthropogenic sources. At sites located along the periphery of western China, the Pb isotopic compositions are much closer to anthropogenic results. Natural and anthropogenic Pb sources are roughly assessed using a simple binary model. The sites with a high anthropogenic fraction are at lower elevations and are relatively close to population centers.

  17. Deep resistivity structure along the Longmen Mountain fault zone in the eastern Tibetan plateau of China

    NASA Astrophysics Data System (ADS)

    Wang, X.; Zhang, G.; Luo, W.; Luo, H.; Cai, X.; Zhou, Y.; Zhang, W.; Qin, Q.

    2012-12-01

    1.Introduction Many researchers (e.g.,Wang et al.,2009) have proposed the relevant knowledge of tectonic evolution and dynamic characteristics of the Longmen Mountain belt as well as the Songpan-Ganzi and Yangtze blocks in the past few decades, the knowledge of shallow thrust nappe tectonic along the belt has then been generally recognized. It's, however, still difficult to image the deep crust and mantle structures and reveal the dynamic mechanism of the crustal formation under the Longmen Mountain. In this study, we carried out the MT experiments along and across the Longmen mountain region and investigated the relationships between the crust structure and seismic activity basing on the latest MT geological results. 2. Field observations We conducted three MT experiment profiles in the eastern Tibetan Plateau. One is along the Mingshan-Guangyuan profile parallel with the structural direction, and another two profiles (Maqu-Gaoliangzhen and Luqu-Hechuan) perpendicular to the Longmen Mountain fault zone. In this study, we use the conventional magnetotelluric (MT) data combine with the long-period magnetotelluric (LMT) data to observe electromagnetic response. The MT and LMT data was observed by using the V8 instrument and LEMI-417, respectively. 3. Conclusion (1) According to the results of MT inversion, we find that the high concentration of stress process along the Songpan-Ganzi block and the Yangtze block colliding zone might result from the deep crust-mantle tough shear Zone of Longmen Mountain expanded to mid-upper crust, and finally leads to a new rupture. This could be one of the focal mechanisms of the Wenchuan earthquake (Ms 8.0) generating. The deep resistivity structure along the Longmen Mountain fault zone can be divided into southern,middle and northern segments from southwest to northeast. The total resistivity of southern segment is lower than the middle and northern portions. We suggest that the upper crust of the Longmen Mountain, south of Dayi

  18. Magnetotelluric study of the Xuefeng mountain area, Hu'nan Province, China

    NASA Astrophysics Data System (ADS)

    Chen, Musen; Xue, Lingxiang; Wang, Yousheng; Zhu, Shengjun

    2016-04-01

    A magnetotelluric study was carried out in the Xuefeng mountain uplift belt and its western margins. A detailed investigation was made of the resistivity of the formations, and reliable data were obtained. The sedimentary cover and basement structure of the Xuefeng mountain area and the deep geological structure were analyzed in detail using magnetotelluric data from the two-dimensional inversion of the resistivity profile data in combination with regional gravity and magnetic data. It was concluded that the tectonic movements were characterized by basement detachment, and north-south ramp. The study area can be divided into a southern uplift zone, a southern thrust-faulted zone, a central uplift zone, and a northern depression zone. This work has provided geophysical evidence that can be used in future studies of the tectonics and petroleum geology of this region.

  19. Carbonate- and silicate-rich globules in the kimberlitic rocks of northwestern Tarim large igneous province, NW China: Evidence for carbonated mantle source

    NASA Astrophysics Data System (ADS)

    Cheng, Zhiguo; Zhang, Zhaochong; Santosh, M.; Hou, Tong; Zhang, Dongyang

    2014-12-01

    We report carbonate- and silicate-rich globules and andradite from the Wajilitage kimberlitic rocks in the northwestern Tarim large igneous province, NW China. The carbonate-rich globules vary in size from 1 to 3 mm, and most have ellipsoidal or round shape, and are composed of nearly pure calcite. The silicate-rich globules are elliptical to round in shape and are typically larger than the carbonate-rich globules ranging from 2 to several centimeters in diameter. They are characterized by clear reaction rims and contain several silicate minerals such as garnet, diopside and phlogopite. The silicate-rich globules, reported here for the first time, are suggested to be related to the origin of andradite within the kimberlitic rocks. Our results show that calcite in the carbonate-rich globules has a high XCa (>0.97) and is characterized by extremely high concentrations of the total rare earth elements (up to 1500 ppm), enrichment in Sr (8521-10,645 ppm) and LREE, and remarkable depletion in Nd, Ta, Zr, Hf and Ti. The calcite in the silicate-rich globules is geochemically similar to those in the carbonate-rich globules except the lower trace element contents. Garnet is dominantly andradite (And59.56-92.32Grs5.67-36.03Pyr0.36-4.61Spe0-0.33) and is enriched in light rare earth elements (LREEs) and relatively depleted in Rb, Ba, Th, Pb, Sr, Zr and Hf. Phlogopite in the silicate-rich globules has a high Mg# ranging from 0.93 to 0.97. The composition of the diopside is Wo45.82-51.39En39.81-49.09Fs0.88-0.95 with a high Mg# ranging from 0.88 to 0.95. Diopside in the silicate-rich globules has low total rare earth element (REE) contents (14-31 ppm) and shows middle REE- (Eu to Gd), slight light REE- and heavy REE-enrichment with elevated Zr, Hf and Sr contents and a negative Nb anomaly in the normalized diagram. The matrix of the kimberlitic rocks are silica undersaturated (27.92-29.31 wt.% SiO2) with low Al2O3 (4.51-5.15 wt.%) and high CaO (17.29-17.77 wt.%) contents. The

  20. [Characteristics of PM10 and PM2.5 concentrations in mountain background region of East China].

    PubMed

    Su, Bin-Bin; Liu, Xin-Dong; Tao, Jun

    2013-02-01

    The online PM10 and PM2.5 concentrations were measured from March 2011 'to February 2012 at the national atmospheric background monitoring station in Wuyishan of Fujian Province to discuss the characteristic of PM10 and PM2.5 concentrations and the impact factors in forest and mountain background region of East China. HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) Model was used to investigate the potential sources of particulates during the pollution episodes. The results showed that the background concentrations of PM10 and PM2.5 were (23 +/- 16) microg.m-3 and (18 +/- 12) microg.m-3, respectively. Seasonal variations of PMl0 and PM2.5 loadings were observed, and loadings decreased in the same order: spring > autumn > winter > summer. PM10 and PM2.5 concentrations were obviously higher in spring than in other seasons because of the transportation of dust storm. The fine particles were the dominant pollutant which accounted for 76% of PM10. The good correlation between PM10/PM2.5 and gas pollutants suggested that regional transportation and secondary aerosol were the major sources in the background station. One episode occurring in April 2011 was related with the transportation of dust storm. However, another episode occurring in September 2011 had close relationship with the transportation of higher pollutant loadings in East China. PMID:23668109

  1. [Characteristics of PM10 and PM2.5 concentrations in mountain background region of East China].

    PubMed

    Su, Bin-Bin; Liu, Xin-Dong; Tao, Jun

    2013-02-01

    The online PM10 and PM2.5 concentrations were measured from March 2011 'to February 2012 at the national atmospheric background monitoring station in Wuyishan of Fujian Province to discuss the characteristic of PM10 and PM2.5 concentrations and the impact factors in forest and mountain background region of East China. HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) Model was used to investigate the potential sources of particulates during the pollution episodes. The results showed that the background concentrations of PM10 and PM2.5 were (23 +/- 16) microg.m-3 and (18 +/- 12) microg.m-3, respectively. Seasonal variations of PMl0 and PM2.5 loadings were observed, and loadings decreased in the same order: spring > autumn > winter > summer. PM10 and PM2.5 concentrations were obviously higher in spring than in other seasons because of the transportation of dust storm. The fine particles were the dominant pollutant which accounted for 76% of PM10. The good correlation between PM10/PM2.5 and gas pollutants suggested that regional transportation and secondary aerosol were the major sources in the background station. One episode occurring in April 2011 was related with the transportation of dust storm. However, another episode occurring in September 2011 had close relationship with the transportation of higher pollutant loadings in East China.

  2. Using 137Cs to Trace Soil Redistribution by Overland Flow in Qilian Mountains, N.W. China

    NASA Astrophysics Data System (ADS)

    Geng, H.; Pan, B.; Huang, B.; Milledge, D.; Dietrich, W.

    2012-12-01

    Many previous studies have suggested theoretic coupling between tectonics, climate, and erosion in long-term landscape evolution. The critical question is: how do tectonics and climate effect erosion? Accordingly, erosion rates derived from modern sediment yield, river incision, cosmogenic nuclides and thermochronological data are estimated in tectonically active mountain ranges to address the question. Erosion rates are useful but time and space scale dependent. Moreover, many measures describe basin averaged erosion so that representation of intra-basin variability of erosion processes is difficult. Mountainous environments generally comprise many processes (e.g frost creep, gelifluction, rock fall, debris flow and overland flow etc). The spatial variability of these processes, makes the relationship between erosion rates and either climate or tectonics difficult to unpack. The Qilian Mountains, located along the northeast margin of the Qinghai-Tibetan Plateau, have been experiencing an average rate of regional uplift of at least 0.2mm/a since the Late Cenozoic. Previous studies have indicated that topographic control (i.e. mean local relief) plays a dominant role in spatial distribution of decadal-scale erosion rates. We now hope to begin to examine the processes that drive landscape evolution in the Qilian Mountains and their relation to catchment properties. Our observations suggest that overland flow is one of the dominant processes in the lower elevation regions of the Qilan Mountains, which are soil-mantled, have a semi-arid climate, and are subject to grazing by domestic animals. We use 137Cs to trace soil redistribution in the top 20 cm of a series of soil-mantled slopes in the Xiying Basin (eastern Qilan Mountains, China). We chose 23 transects across a range of gradients and land covers, collecting bulk samples to a depth of 0.2 m at 5 m intervals (total n=245). We also collected samples at a reference (no erosion) site at 0.01 m intervals to 0.2 m

  3. [Influence of atmospheric transport on air pollutant levels at a mountain background site of East China].

    PubMed

    Su, Bin-Bin; Xu, Ju-Yang; Zhang, Ruo-Yu; Ji, Xian-Xin

    2014-08-01

    Transport characteristics of air pollutants transported to the background atmosphere of East China were investigated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) 4.8 model driven by NCEP reanalysis data during June 2011 to May 2012. Based on the air pollutants monitoring data collected at the National atmospheric background monitoring station (Wuyishan station) in Fujian Province, characteristics of different clustered air masses as well as the origins of highly polluted air masses were further examined. The results showed that 65% of all the trajectories, in which air masses mainly passed over highly polluted area of East China, Jiangxi province and upper air in desert areas of Northwest China, carried polluted air to the station, while the rest of trajectories (35%) with air masses originated from ocean could effectively remove air pollutants at the Wuyishan station. However, the impact on the air pollutants for each air mass group varied with seasons. Elevated SO2 concentrations observed at the background station were mainly influenced by coal burning activities in Northern China during heating season. The high CO concentrations were likely associated with the pollutants emission in the process of coal production and consumption in Anhui province. The elevated NO(x), O3, PM10 and PM2.5 concentrations were mostly impacted by East China with high levels of air pollutants.

  4. [Ecological distribution and spatial niche of pheasants in the Karst mountains of southwest Guangxi Province, China].

    PubMed

    Yu, Chen-Xing; Yang, Gang; Li, Dong; Zhou, Fang

    2011-10-01

    The Karst mountain area along the Sino-Vietnam border of southwest Guangxi has been designated a "Global Biodiversity Hotspot" since 2003. We conducted a survey of pheasant species in this area, with seven species recorded, namely Chinese Francolin (Francolinus pintadeanus), Bar-backed Partridge (Arborophila brunneopectus), Mountain Bamboo Partridge (Bambusicola fytchii), Chinese Bamboo Partridge (Bambusicola thoracica), Red Junglefowl (Gallus gallus), Silver Pheasant (Lophura nycthemera) and Common Pheasant (Phasianus colchicus). Analysis and comparison of the distribution and spatial niche of these seven pheasant species revealed that Red Junglefowl had the widest spatial niche, while Chinese Francolin had the narrowest. The spatial niche overlap index was high between Chinese Francolin and the Common Pheasant, Chinese Bamboo Partridge, and Red Junglefowl. With narrow distribution range, small population, and lower ecological adaptability, it is likely that the Bar-backed Partridge is the most vulnerable pheasant species in this area. The results suggest more research and conservation measures are required for pheasant habitat protection in the Karst areas of southwest Guangxi. PMID:22006809

  5. Isolation, diversity and acetylcholinesterase inhibitory activity of the culturable endophytic fungi harboured in Huperzia serrata from Jinggang Mountain, China.

    PubMed

    Wang, Ya; Lai, Zheng; Li, Xi-Xi; Yan, Ri-Ming; Zhang, Zhi-Bin; Yang, Hui-Lin; Zhu, Du

    2016-02-01

    Huperzia serrata has many important medicinal properties with proven pharmacological potential. Some of these properties may be mediated by its endophytic fungi. To test this hypothesis, in the present study, we provided a first insights into evaluating the species composition and acetylcholinesterase (AChE) inhibitory activity of the culturable endophytic fungi of H. serrata from the regional at Jinggang Mountain in southeastern China. A total number of 885 fungal isolates distributed across 44 genera and 118 putative species were obtained from 1422 fragments of fine H. serrata roots, stems and leaves base on ITS-rDNA sequences BLAST analysis. The endophytic fungi were phylogenetically diverse and species-rich, with high rate of colonization and isolation. The assemble of endophytic fungi consisted mainly of Ascomycota (97.15%), followed by Basidiomycota (1.92%) and unknown fungal species (0.90%). Colletotrichum (64.29%), Phyllosticta (3.39%), Hypoxylon (2.81%), Xylaria (2.25%) and Nigrospora (2.04%) were the most abundant genera, whereas the remaining genera were infrequent groups. Although, roots yielded low abundance strains, the diverse and species-rich were both higher than that of stems and leaves. In addition, out of the 247 endophytic fungi strains determinated, 221 fungal extracts showed AChE inhibition activities in vitro. Among them, 22 endophytic fungi strains achieved high inhibitory activity (≥50%) on AChE which belongs to 13 genera and five incertae sedis strains. Four endophytic fungi designated as JS4 (Colletotrichum spp.), FL14 (Ascomycota spp.), FL9 (Sarcosomataceae spp.) and FL7 (Dothideomycetes spp.) were displayed highly active (≥80%) against AChE, which the inhibition effects were even more intense than the positive control. Our findings highlight that H. serrata grown in Jinggang Mountain harbors a rich and fascinating endophytic fungus community with potential AChE inhibitory activity, which could further broaden the natural

  6. Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China.

    PubMed

    Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

    2015-01-01

    Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies. PMID:26382763

  7. Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China

    PubMed Central

    Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

    2015-01-01

    Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies. PMID:26382763

  8. Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China.

    PubMed

    Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

    2015-01-01

    Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies.

  9. [Microbial community and its activities in canopy- and understory humus of two montane forest types in Ailao Mountains, Northwest China].

    PubMed

    Liu, Yong-jie; Liu, Wen-yao; Chen, Lin; Zhang, Han-bo; Wang, Gao-sheng

    2010-09-01

    Mid-montane moist evergreen broadleaved forest (MMF) and top-montane dwarf mossy forest (DMF) are the two major natural forest types in subtropical mountainous area of Ailao Mountains, Northwest China. In this paper, a comparative study was made on the microbial composition, quantity, biochemical activity, metabolic activity, and their seasonal dynamics in the canopy- and understory humus of the two forest types. The composition, quantity, and metabolic activity of the microbes in the canopy humus of dominant tree species in MMF and DMF were also analyzed. In the canopy humus of the two forest types, the amounts of fungi and actinomycetes, microbial biomass C and N, and intensities of nitrogen fixation and cellulose decomposition were significantly higher than those in understory humus. Meanwhile, the amount of cellulose-decomposing microbes (ACDM), cellulose decomposition intensity, microbial biomass C and N, and metabolic activity in the canopy humus of MMF were significantly higher than those of DMF. The amounts of bacteria, fungi, and aerobic nitrogen-fixing bacteria (ANFB) and the metabolic activity in the canopy humus of MMF and DMF were significantly higher in wet season than in dry season, while a contradictory trend was observed on the amount of actinomycetes. No significant difference was observed on the amount of ACDM between wet season and dry season. For the two forest types, the amounts of microbes and their biochemical activities in canopy humus had a larger seasonal variation range than those in understory humus. There was a significant difference in the amounts of the microbes in canopy humus among the dominant tree species in MMF and DMF, especially in wet season. The microbes in canopy humus played important roles in maintaining the biodiversity of epiphytes in the canopy, and in supplying the needed nutrients for the vigorous growth of the epiphytes.

  10. Monitoring and modeling of cold region hydrological processes in a high mountain river basin in the upstream area of the Heihe River Basin of China

    NASA Astrophysics Data System (ADS)

    Li, X.; Che, T.; Li, H.; Jin, R.; Liu, S.; Huang, C.

    2015-12-01

    We provide an overview of a high mountain river basin observing system in the Qilian Mountains of China. Mountain cryosphere is very sensitive to climate change, however, monitoring and modeling of cryospheric process and its interaction with hydrology and ecology needs to be further strengthened. We establish a multi-scale high mountain river basin observing system in the upstream area of the Heihe River Basin, Qilian Mountains of China. This system consists of flux towers on alpine tundra, alpine meadow and alpine steppes, a network of automatic meteorological stations, a wireless sensor network of soil moisture, soil temperature, snow depth, and precipitation, and two super observatories for monitoring snow and frozen soil, respectively. Super-high resolution (1 meter) DEMs of four experiment sub-watersheds (each about 20-40 km2) within this river basin were obtained via airborne LiDAR remote sensing.We introduce the data obtained since 2012 and present some preliminary modeling and data assimilation results. The results show that runoff, precipitation, snowmelt, and glacier melt keep increasing in the upstream area of the Heihe River Basin due to a warming climate. The ratio of snowmelt in total runoff has increased and the onset of snowmelt has gone ahead. The contribution of glacier melt to total runoff has almost doubled in the past decade. Frozen soil melt advances in time as well, and it may also contributes to the increase of the portion of baseflow in total runoff.This observatory has joined the International Network for Alpine Research Catchment Hydrology (NARCH) and will work as a unique site to monitor cryospheric and hydroclimatological changes in very high mountains.

  11. China.

    PubMed

    1983-12-01

    This discussion of China focuses on the following: the people; geography; history (early history, 20th century China, the People's Republic of China; the "Great Leap Forward" and the Sino Soviet Split, the Cultural Revolution, and Mao's death and present directions); government (state structure, Chinese Communist Party, and legal system); education; economy; foreign relations; defense; and relations between China and the US. As of 1982, China's population totaled just over 1.008 billion with an annual growth rate of 1.5%. Life expectancy is 68 years. Government authorities endorsed birth control in the 1950s, played it down in 1958, and began to promote it again in 1962. The present family planning program began in the early 1970s and has become more fully mobilized since 1979. The largest ethnic group is the Han Chinese, who constitute 93.3% of the total population. The People's Republic of China, located in eastern Asia, is almost as large as the European continent. 2/3 of China's area is mountainous or semidesert; only about 1/10 is cultivated. China is the oldest continuous major world civilization with records dating back about 3500 years. Mao's death in September 1976 removed a towering figure from Chinese politics and set off a scramble for succession. The post 11th Party Congress leadership has emphasized economic development and renounced the mass political movements of prior years. Important educational reforms were made in early 1978. Since 1979, the Chinese leadership has moved toward more pragmatic positions in almost all fields. The Chinese government has always been subordinate to the Chinese Communist Party (CCP), its role being to implement party policies. The primary instruments of state power are the State Council, an executive body corresponding to a cabinet, and the NPC, a legislative body. China has made impressive progress in primary education since 1949. About 93% of eligible children are enrolled in 1st grade, though only 65% finish primary

  12. Influence of human activities on the historical and current distribution of Sichuan snub-nosed monkeys in the Qinling Mountains, China.

    PubMed

    Wang, Chengliang; Wang, Xiaowei; Qi, Xiaoguang; Guo, Songtao; Zhao, Haitao; Wei, Wei; Li, Baoguo

    2014-01-01

    Due to their rich animal diversity and the presence of rare and endemic species, the Qinling Mountains are listed as a significant global biodiversity area. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) has been distributed in this area since the Middle Pleistocene. Due to the gradual encroachment of humans into their habitat, both the distribution range and population sizes of R. roxellana have significantly decreased. Based on literature research as well as field and questionnaires, we investigated the influence of human activities on R. roxellana distribution in the Qinling Mountains. Human activity within the habitat of R. roxellana began in the Stone and Bronze Ages, though initially it had no significant influence on its populations. When China entered the Iron Age, however, different historical and social periods had a considerable impact on R. roxellana distribution. Although national and provincial level governments introduced strict protection policies with the establishment of the People's Republic of China in 1949, human activities continued to influence R. roxellana distribution. Since the launch of the Natural Forest Protection Project across the Qinling Mountains in 1999, the quality of R. roxellana habitat has shown marked improvement. This research will help promote the survival and conservation of the Sichuan snub-nosed monkey in the Qinling Mountains. PMID:25612509

  13. Wild food plants and wild edible fungi in two valleys of the Qinling Mountains (Shaanxi, central China)

    PubMed Central

    2013-01-01

    Background The aim of the study was to investigate knowledge and use of wild food plants in two mountain valleys separated by Mount Taibai – the highest peak of northern China and one of its biodiversity hotspots, each adjacent to species-rich temperate forest vegetation. Methods Seventy two free lists were collected among the inhabitants of two mountain valleys (36 in each). All the studied households are within walking distance of primary forest vegetation, however the valleys differed in access to urban centers: Houzhenzi is very isolated, and the Dali valley has easier access to the cities of central Shaanxi. Results Altogether, 185 wild food plant species and 17 fungi folk taxa were mentioned. The mean number of freelisted wild foods was very high in Houzhenzi (mean 25) and slightly lower in Dali (mean 18). An average respondent listed many species of wild vegetables, a few wild fruits and very few fungi. Age and male gender had a positive but very low effect on the number of taxa listed. Twelve taxa of wild vegetables (Allium spp., Amaranthus spp., Caryopteris divaricata, Helwingia japonica, Matteucia struthiopteris, Pteridium aquilinum, Toona sinensis, Cardamine macrophylla, Celastrus orbiculatus, Chenopodium album, Pimpinella sp., Staphylea bumalda &S. holocarpa), two species of edible fruits (Akebia trifoliata, Schisandra sphenanthera) and none of the mushrooms were freelisted by at least half of the respondents in one or two of the valleys. Conclusion The high number of wild vegetables listed is due to the high cultural position of this type of food in China compared to other parts of the world, as well as the high biodiversity of the village surroundings. A very high proportion of woodland species (42%, double the number of the ruderal species used) among the listed taxa is contrary to the general stereotype that wild vegetables in Asia are mainly ruderal species. The very low interest in wild mushroom collecting is noteworthy and is difficult to

  14. [Community stability for spruce-fir forest at different succession stages in Changbai Mountains, Northeast China].

    PubMed

    Zhang, Meng-tao; Zhang, Qing; Kang, Xin-gang; Yang, Ying-jun; Xu, Guang; Zhang, Li-xin

    2015-06-01

    Based on the analysis of three forest communities (polar-birch secondary forest, spruce-fir mixed forest, spruce-fir near pristine forest) in Changbai Mountains, a total of 22 factors of 5 indices, including the population regeneration, soil fertility (soil moisture and soli nutrient), woodland productivity and species diversity that reflected community characteristics were used to evaluate the stability of forest community succession at different stages by calculating subordinate function values of a model based on fuzzy mathematics. The results that the indices of population regeneration, soli nutrient, woodland productivity and species diversity were the highest in the spruce-fir mixed forest, and the indices of soil moisture were the highest in the spruce-fir near-pristine forest. The stability of three forest communities was in order of natural spruce-fir mixed forest > spruce-fir near pristine forest > polar-birch secondary forest.

  15. [Age structure and dynamics of Quercus wutaishanica population in Lingkong Mountain of Shanxi Province, China].

    PubMed

    Zhang, Jie; Shangguan, Tie-Liang; Duan, Yi-Hao; Guo, Wei; Liu, Wei-Hua; Guo, Dong-Gang

    2014-11-01

    Using the plant survivorship theory, the age structure, and the relationship between tree height and diameter (DBH) of Quercus wutaishanica population in Lingkong Mountain were analyzed, and the static life table was compiled and the survival curve plotted. The shuttle shape in age structure of Q. wutaishanica population suggested its temporal stability. The linear regression significantly fitted the positive correlation between tree height and DBH. The maximal life expectancy was observed among the trees beyond the age of the highest mortality and coincided with the lowest point of mortality density, suggesting the strong vitality of the seedlings and young trees that survived in the natural selection and intraspecific competition. The population stability of the Q. wutaishanica population was characterized by the Deevey-II of the survival curve. The dynamic pattern was characterized by the recession in the early phase, growth in the intermediate phase, and stability in the latter phase. PMID:25898607

  16. [Community stability for spruce-fir forest at different succession stages in Changbai Mountains, Northeast China].

    PubMed

    Zhang, Meng-tao; Zhang, Qing; Kang, Xin-gang; Yang, Ying-jun; Xu, Guang; Zhang, Li-xin

    2015-06-01

    Based on the analysis of three forest communities (polar-birch secondary forest, spruce-fir mixed forest, spruce-fir near pristine forest) in Changbai Mountains, a total of 22 factors of 5 indices, including the population regeneration, soil fertility (soil moisture and soli nutrient), woodland productivity and species diversity that reflected community characteristics were used to evaluate the stability of forest community succession at different stages by calculating subordinate function values of a model based on fuzzy mathematics. The results that the indices of population regeneration, soli nutrient, woodland productivity and species diversity were the highest in the spruce-fir mixed forest, and the indices of soil moisture were the highest in the spruce-fir near-pristine forest. The stability of three forest communities was in order of natural spruce-fir mixed forest > spruce-fir near pristine forest > polar-birch secondary forest. PMID:26572010

  17. Ecology of testate amoebae in Dajiuhu peatland of Shennongjia Mountains, China, in relation to hydrology

    NASA Astrophysics Data System (ADS)

    Qin, Yangmin; Payne, Richard J.; Gu, Yansheng; Huang, Xianyu; Wang, Hongmei

    2012-03-01

    This study investigates the testate amoeba communities of a large peatland in Central China. The ecology and seasonal variability of testate amoeba communities were studied during 2009-2010. Investigation of environmental controls using ordination showed that the relationship between testate amoeba communities and depth to water table (DWT) and pH are extremely weak. The small proportion of variance explained by water table depth here (only 1.9% in the full data) shows that the hydrological control is weaker than we expected in this peatland, and weaker than any study we are aware of using a similar methodology. Attempts to develop species-environment (transfer function) models or identify indicator species for future palaeoecological studies were unsuccessful. Previous large-scale studies of peatland testate amoeba ecology have been largely restricted to Europe and North America and results have been relatively consistent among studies. Our results contrast with this consensus and suggest that at least in minerotrophic peatlands in China testate amoeba communities may be primarily controlled by different environmental variables. In China, testate amoebae have been relatively little studied but may prove to be valuable for a variety of applications in palaeoecology and biomonitoring and much further work is required.

  18. Dispersal, niche, and isolation processes jointly explain species turnover patterns of nonvolant small mammals in a large mountainous region of China.

    PubMed

    Wen, Zhixin; Quan, Qing; Du, Yuanbao; Xia, Lin; Ge, Deyan; Yang, Qisen

    2016-02-01

    Understanding the mechanisms that govern the spatial patterns of species turnover (beta diversity) has been one of the fundamental issues in biogeography. Species turnover is generally recognized as strong in mountainous regions, but the way in which different processes (dispersal, niche, and isolation) have shaped the spatial turnover patterns in mountainous regions remains largely unexplored. Here, we explore the directional and elevational patterns of species turnover for nonvolant small mammals in the Hengduan Mountains of southwest China and distinguish the relative roles of geographic distance, environmental distance, and geographic isolation on the patterns. The spatial turnover was assessed using the halving distance (km), which was the geographic distance that halved the similarity (Jaccard similarity) from its initial value. The halving distance was calculated for the linear, logarithmic, and exponential regression models between Jaccard similarity and geographic distance. We found that the east-west turnover is generally faster than the south-north turnover for high-latitudinal regions in the Hengduan Mountains and that this pattern corresponds to the geographic structure of the major mountain ranges and rivers that mainly extend in a south-north direction. There is an increasing trend of turnover toward the higher-elevation zones. Most of the variation in the Jaccard similarity could be explained by the pure effect of geographic distance and the joint effects of geographic distance, environmental distance, and average elevation difference. Our study indicates that dispersal, niche, and isolation processes are all important determinants of the spatial turnover patterns of nonvolant small mammals in the Hengduan Mountains. The spatial configuration of the landscape and geographic isolation can strongly influence the rate of species turnover in mountainous regions at multiple spatial scales. PMID:26941938

  19. Elevation-related variation in leaf stomatal traits as a function of plant functional type: evidence from Changbai Mountain, China.

    PubMed

    Wang, Ruili; Yu, Guirui; He, Nianpeng; Wang, Qiufeng; Xia, Fucai; Zhao, Ning; Xu, Zhiwei; Ge, Jianping

    2014-01-01

    Understanding the variation in stomatal characteristics in relation to climatic gradients can reveal the adaptation strategies of plants, and help us to predict their responses to future climate changes. In this study, we investigated stomatal density (SD) and stomatal length (SL) in 150 plant species along an elevation gradient (540-2357 m) in Changbai Mountain, China, and explored the patterns and drivers of stomatal characteristics across species and plant functional types (PFTs: trees, shrubs, and herbs). The average values of SD and SL for all species combined were 156 mm(-2) and 35 µm, respectively. SD was higher in trees (224 mm(-2)) than in shrubs (156 mm(-2)) or herbs (124 mm(-2)), and SL was largest in herbs (37 µm). SD was negatively correlated with SL in all species and PFTs (P < 0.01). The relationship between stomatal characteristics and elevation differed among PFTs. In trees, SD decreased and SL increased with elevation; in shrubs and herbs, SD initially increased and then decreased. Elevation-related differences in SL were not significant. PFT explained 7.20-17.6% of the total variation in SD and SL; the contributions of CO2 partial pressure (P CO2), precipitation, and soil water content (SWC) were weak (0.02-2.28%). Our findings suggest that elevation-related patterns of stomatal characteristics in leaves are primarily a function of PFT, and highlight the importance of differences among PFTs in modeling gas exchange in terrestrial ecosystems under global climate change.

  20. Predictions of soil organic carbon using laboratory-based hyperspectral data in the northern Tianshan mountains, China.

    PubMed

    Yang, Hongfei; Li, Jianlong

    2013-05-01

    This paper presents a study dealing with soil organic carbon (SOC) estimation of soil through the combination of soil spectroscopy and multivariate stepwise linear regression. Soil samples were collected in the three sub-regions, dominated by brown calcic soil, in the northern Tianshan Mountains, China. Spectral measurements for all soil samples were performed in a controlled laboratory environment by a portable ASD FieldSpec FR spectrometer (350-2,500 nm). Twelve types of transformations were applied to the soil reflectance to remove the noise and to linearize the correlation between reflectance and SOC content. Based on the spectral reflectance and its derivatives, hyperspectral models can be built using correlation analysis and multivariable statistical methods. The results show that the main response range of soil organic carbon is between 400 and 750 nm. Correlation analysis indicated that SOC has stronger correlation with the second derivative than with the original reflectance and other transformations data. The two models developed with laboratory spectra gave good predictions of SOC, with root mean square error (RMSE) <5.0. The use of the full visible near-infrared spectral range gave better SOC predictions than using visible separately. The multivariate stepwise linear regression of second derivate model (model A) is optimal for estimating SOC content, with a determination coefficient of 0.894 and RMSE of 0.322. The results of this research study indicated that, for the grassland regions, combining soil spectroscopy and mathematical statistical methods does favor accurate prediction of SOC.

  1. Modeling spring habitat requirements of the endangered brown eared pheasant Crossoptilon mantchuricum in the Huanglong Mountains, Shaanxi Province, China.

    PubMed

    Li, Hongqun; Yue, Bisong; Lian, Zhenmin; Zhao, Hongfeng; Zhao, Delong; Xiao, Xiangming

    2012-09-01

    A detailed understanding of the habitat needs of brown eared pheasants (Crossoptilon mantchuricum) is essential for conserving the species. We carried out field surveys in the Huanglong Mountains of Shaanxi Province, China, from March to June in 2007 and 2008. We arrayed a total of 206 grid plots (200 × 200 m) along transects in 2007 and 2008 and quantified a suite of environmental variables for each one. In the optimal logistic regression model, the most important variables for brown eared pheasants were slope degree, tree cover, distance to nearest water, cover and depth of fallen leaves. Hosmer and Leweshow goodness-of-fit tests explained that logistic models for the species were good fits. The model suggested that spring habitat selection of the brown eared pheasant was negatively related to distance to nearest water and slope degree, and positively to cover of trees and cover and depth of fallen leaves. In addition, the observed detected and undetected grids in 2007 did not show significant differences with predictions based on the model. These results showed that the model could well predict the habitat selection of brown eared pheasants. Based on these predictive models, we suggest that habitat management plans incorporating this new information can now focus more effectively on restrictions on the number of tourists entering the nature reserve, prohibition of firewood collection, livestock grazing, and medicinal plant harvesting by local residents in the core areas, protection of mixed forest and sources of the permanent water in the reserve, and use of alternatives to firewood.

  2. Effects of permafrost thaw on carbon emissions under aerobic and anaerobic environments in the Great Hing'an Mountains, China.

    PubMed

    Song, Changchun; Wang, Xianwei; Miao, Yuqing; Wang, Jiaoyue; Mao, Rong; Song, Yanyu

    2014-07-15

    The carbon (C) pool of permafrost peatland is very important for the global C cycle. Little is known about how permafrost thaw could influence C emissions in the Great Hing'an Mountains of China. Through aerobic and anaerobic incubation experiments, we studied the effects of permafrost thaw on CH4 and CO2 emissions. The rates of CH4 and CO2 emissions were measured at -10, 0 and 10°C. Although there were still C emissions below 0°C, rates of CH4 and CO2 emissions significantly increased with permafrost thaw under aerobic and anaerobic conditions. The C release under aerobic conditions was greater than under anaerobic conditions, suggesting that permafrost thaw and resulting soil environment change should be important influences on C emissions. However, CH4 stored in permafrost soils could affect accurate estimation of CH4 emissions from microbial degradation. Calculated Q10 values in the permafrost soils were significantly higher than values in active-layer soils under aerobic conditions. Our results highlight that permafrost soils have greater potential decomposability than soils of the active layer, and such carbon decomposition would be more responsive to the aerobic environment.

  3. Community Structure and Survival of Tertiary Relict Thuja sutchuenensis (Cupressaceae) in the Subtropical Daba Mountains, Southwestern China

    PubMed Central

    Tang, Cindy Q.; Yang, Yongchuan; Ohsawa, Masahiko; Momohara, Arata; Yi, Si-Rong; Robertson, Kevin; Song, Kun; Zhang, Shi-Qiang; He, Long-Yuan

    2015-01-01

    A rare coniferous Tertiary relict tree species, Thuja sutchuenensis Franch, has survived in the Daba Mountains of southwestern China. It was almost eliminated by logging during the past century. We measured size and age structures and interpreted regeneration dynamics of stands of the species in a variety of topographic contexts and community associations. Forest communities containing T. sutchuenensis were of three types: (1) the Thuja community dominated by T. sutchuenensis, growing on cliffs; (2) the Thuja-Quercus-Cyclobalanopsis community dominated by T. sutchuenensis, Quercus engleriana and Cyclobalanopsis oxyodon, along with Fagus engleriana and Carpinus fargesiana, on steep slopes; (3) the Thuja-Tsuga-Quercus community dominated by T. sutchuenensis, Tsuga chinensis, and Quercus spinosa, on crest ridges. The established seedlings/saplings were found in limestone crevices, on scarred cliff-faces, cliff-edges, fallen logs, canopy gaps and forest margins. The radial growth rate was 0.5-1.1 mm per year. Its growth forms were distorted. It had strong sprouting ability after disturbances. The T. sutchuenensis population thrives on cliffs where there is little competition from other species because of harsh conditions and rockslide disturbances. It is shade-intolerant but stress-tolerant. Its regeneration has depended on natural disturbances. PMID:25928845

  4. Fractal Characteristics of Soil Retention Curve and Particle Size Distribution with Different Vegetation Types in Mountain Areas of Northern China

    PubMed Central

    Niu, Xiang; Gao, Peng; Wang, Bing; Liu, Yu

    2015-01-01

    Based on fractal theory, the fractal characteristics of soil particle size distribution (PSD) and soil water retention curve (WRC) under the five vegetation types were studied in the mountainous land of Northern China. Results showed that: (1) the fractal parameters of soil PSD and soil WRC varied greatly under each different vegetation type, with Quercus acutissima Carr. and Robina pseudoacacia Linn. mixed plantation (QRM) > Pinus thunbergii Parl. and Pistacia chinensis Bunge mixed plantation (PPM) > Pinus thunbergii Parl. (PTP) > Juglans rigia Linn. (JRL) > abandoned grassland (ABG); (2) the soil fractal dimensions of woodlands (QRM, PPM, PTP and JRL) were significantly higher than that in ABG, and mixed forests (QRM and PPM) were higher than that in pure forests (PTP and JRL); (3) the fractal dimension of soil was positively correlated with the silt and clay content but negatively correlated with the sand content; and (4) the fractal dimension of soil PSD was positively correlated with the soil WRC. These indicated that the fractal parameters of soil PSD and soil WRC could act as quantitative indices to reflect the physical properties of the soil, and could be used to describe the influences of the Return Farmland to Forests Projects on soil structure. PMID:26633458

  5. Elevation-related variation in leaf stomatal traits as a function of plant functional type: evidence from Changbai Mountain, China.

    PubMed

    Wang, Ruili; Yu, Guirui; He, Nianpeng; Wang, Qiufeng; Xia, Fucai; Zhao, Ning; Xu, Zhiwei; Ge, Jianping

    2014-01-01

    Understanding the variation in stomatal characteristics in relation to climatic gradients can reveal the adaptation strategies of plants, and help us to predict their responses to future climate changes. In this study, we investigated stomatal density (SD) and stomatal length (SL) in 150 plant species along an elevation gradient (540-2357 m) in Changbai Mountain, China, and explored the patterns and drivers of stomatal characteristics across species and plant functional types (PFTs: trees, shrubs, and herbs). The average values of SD and SL for all species combined were 156 mm(-2) and 35 µm, respectively. SD was higher in trees (224 mm(-2)) than in shrubs (156 mm(-2)) or herbs (124 mm(-2)), and SL was largest in herbs (37 µm). SD was negatively correlated with SL in all species and PFTs (P < 0.01). The relationship between stomatal characteristics and elevation differed among PFTs. In trees, SD decreased and SL increased with elevation; in shrubs and herbs, SD initially increased and then decreased. Elevation-related differences in SL were not significant. PFT explained 7.20-17.6% of the total variation in SD and SL; the contributions of CO2 partial pressure (P CO2), precipitation, and soil water content (SWC) were weak (0.02-2.28%). Our findings suggest that elevation-related patterns of stomatal characteristics in leaves are primarily a function of PFT, and highlight the importance of differences among PFTs in modeling gas exchange in terrestrial ecosystems under global climate change. PMID:25517967

  6. Long-Term Water and Sediment Change Detection in a Small Mountainous Tributary of the Lower Pearl River, China

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Lu, X. X.

    Hydrological regimes of river systems have been changing both qualitatively and quantitatively due to the profound human disturbances, such as river diversions, damming, and land use change. In this study, a mountainous tributary (the Luodingjiang River) of the lower Pearl River, China, was investigated to illustrate the impacts from human activities on river systems during the period 1959-2002. Mann-Kendall test and Spearman test for gradual trend and Pettitt test for abrupt change were employed to investigate the hydrological characteristics of the Luodingjiang River. Annual minimum water discharge and annual sediment yield series have significant increasing and decreasing trends, respectively, and also significant upward and downward shifts were detected by abrupt change tests, respectively, for these two data series. Neither statistically significant trends nor abrupt shift were found for annual maximum water discharge and annual mean water discharge series. The detected changes both in water and sediment point to the impacts of reservoir constructions, water diversion programs as well as land use change. However, the sediment-increasing impacts from other anthropogenic disturbances, such as road construction and mining, cannot be discerned from the recent hydrological responses.

  7. Effects of tourism and topography on vegetation diversity in the subalpine meadows of the Dongling Mountains of Beijing, China.

    PubMed

    Zhang, Jin-Tun; Xiang, ChunLing; Li, Min

    2012-02-01

    Subalpine meadows in the Dongling Mountains (located at E115º26'-115º40', N40º00'-40º05') of Beijing, China are important for tourism and the provision of ecosystem services. However, because of poor management serious degradation has occurred on these subalpine meadows. The aim of this paper is to present a quantitative analysis of effects of tourism disturbance and topography on the status and diversity of montane meadow communities and to provide direction for improved management. Sixty quadrats of 2 × 2 m(2) along 10 transects were set up to collect data on site characteristics and vegetation status. The relationships between community composition and structure, species diversity, and tourism disturbance and topographic variables were analyzed by multivariate methods (TWINSPAN and CCA). The results showed that eight meadow communities were identified by TWINSPAN. Most of them were seriously degraded. The first CCA axis identified an elevation and tourism disturbance intensity gradient, which illustrated that tourism disturbance and elevation were most important factors influencing meadow types, composition and structure. Some resistant species and response species to tourism disturbance were identified and can be used as indicator species of tourism disturbance. Species richness, heterogeneity and evenness were closely related to tourism disturbance and elevation. It is concluded that tourism disturbance must be controlled to enable grassland rehabilitation to occur in the meadows. Measures of effective management of the meadows were discussed.

  8. Fractal Characteristics of Soil Retention Curve and Particle Size Distribution with Different Vegetation Types in Mountain Areas of Northern China.

    PubMed

    Niu, Xiang; Gao, Peng; Wang, Bing; Liu, Yu

    2015-12-03

    Based on fractal theory, the fractal characteristics of soil particle size distribution (PSD) and soil water retention curve (WRC) under the five vegetation types were studied in the mountainous land of Northern China. Results showed that: (1) the fractal parameters of soil PSD and soil WRC varied greatly under each different vegetation type, with Quercus acutissima Carr. and Robina pseudoacacia Linn. mixed plantation (QRM) > Pinus thunbergii Parl. and Pistacia chinensis Bunge mixed plantation (PPM) > Pinus thunbergii Parl. (PTP) > Juglans rigia Linn. (JRL) > abandoned grassland (ABG); (2) the soil fractal dimensions of woodlands (QRM, PPM, PTP and JRL) were significantly higher than that in ABG, and mixed forests (QRM and PPM) were higher than that in pure forests (PTP and JRL); (3) the fractal dimension of soil was positively correlated with the silt and clay content but negatively correlated with the sand content; and (4) the fractal dimension of soil PSD was positively correlated with the soil WRC. These indicated that the fractal parameters of soil PSD and soil WRC could act as quantitative indices to reflect the physical properties of the soil, and could be used to describe the influences of the Return Farmland to Forests Projects on soil structure.

  9. Community Structure and Survival of Tertiary Relict Thuja sutchuenensis (Cupressaceae) in the Subtropical Daba Mountains, Southwestern China.

    PubMed

    Tang, Cindy Q; Yang, Yongchuan; Ohsawa, Masahiko; Momohara, Arata; Yi, Si-Rong; Robertson, Kevin; Song, Kun; Zhang, Shi-Qiang; He, Long-Yuan

    2015-01-01

    A rare coniferous Tertiary relict tree species, Thuja sutchuenensis Franch, has survived in the Daba Mountains of southwestern China. It was almost eliminated by logging during the past century. We measured size and age structures and interpreted regeneration dynamics of stands of the species in a variety of topographic contexts and community associations. Forest communities containing T. sutchuenensis were of three types: (1) the Thuja community dominated by T. sutchuenensis, growing on cliffs; (2) the Thuja-Quercus-Cyclobalanopsis community dominated by T. sutchuenensis, Quercus engleriana and Cyclobalanopsis oxyodon, along with Fagus engleriana and Carpinus fargesiana, on steep slopes; (3) the Thuja-Tsuga-Quercus community dominated by T. sutchuenensis, Tsuga chinensis, and Quercus spinosa, on crest ridges. The established seedlings/saplings were found in limestone crevices, on scarred cliff-faces, cliff-edges, fallen logs, canopy gaps and forest margins. The radial growth rate was 0.5-1.1 mm per year. Its growth forms were distorted. It had strong sprouting ability after disturbances. The T. sutchuenensis population thrives on cliffs where there is little competition from other species because of harsh conditions and rockslide disturbances. It is shade-intolerant but stress-tolerant. Its regeneration has depended on natural disturbances. PMID:25928845

  10. Fractal Characteristics of Soil Retention Curve and Particle Size Distribution with Different Vegetation Types in Mountain Areas of Northern China.

    PubMed

    Niu, Xiang; Gao, Peng; Wang, Bing; Liu, Yu

    2015-12-01

    Based on fractal theory, the fractal characteristics of soil particle size distribution (PSD) and soil water retention curve (WRC) under the five vegetation types were studied in the mountainous land of Northern China. Results showed that: (1) the fractal parameters of soil PSD and soil WRC varied greatly under each different vegetation type, with Quercus acutissima Carr. and Robina pseudoacacia Linn. mixed plantation (QRM) > Pinus thunbergii Parl. and Pistacia chinensis Bunge mixed plantation (PPM) > Pinus thunbergii Parl. (PTP) > Juglans rigia Linn. (JRL) > abandoned grassland (ABG); (2) the soil fractal dimensions of woodlands (QRM, PPM, PTP and JRL) were significantly higher than that in ABG, and mixed forests (QRM and PPM) were higher than that in pure forests (PTP and JRL); (3) the fractal dimension of soil was positively correlated with the silt and clay content but negatively correlated with the sand content; and (4) the fractal dimension of soil PSD was positively correlated with the soil WRC. These indicated that the fractal parameters of soil PSD and soil WRC could act as quantitative indices to reflect the physical properties of the soil, and could be used to describe the influences of the Return Farmland to Forests Projects on soil structure. PMID:26633458

  11. Reconstruction and analysis of the past five centuries of streamflow on northern slopes on Tianshan Mountains in Northern Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Yang, Yuhui; Chen, Yaning; Wang, Minzhong; Sun, Huilan

    2016-03-01

    We examined the changes in streamflow on the northern slopes of the Tianshan Mountains in northern Xinjiang, China, over two time scales: the past 500 years, based on dendrochronology data; and the past 50 years, based on streamflow data from hydrological stations. The method of artificial neural networks built from the data of the 50-year period was used to reconstruct the streamflow of the 500-year period. The results indicate that streamflow has undergone seven high-flow periods and four low-flow periods during the past 500 years. To identify possible transition points in the streamflow, we applied the Mann-Kendall and running T tests to the 50- and 500-year periods, respectively. During the past 500 years, streamflow has changed significantly from low to high flow about three to four times, and from high to low flow about three to five times. Over the recent 50 years, there have been three phases of variation in river runoff, and the most distinct transition of streamflow occurred in 1996.

  12. Woody species diversity in forest plantations in a mountainous region of Beijing, China: effects of sampling scale and species selection.

    PubMed

    Zhang, Yuxin; Zhang, Shuang; Ma, Keming; Fu, Bojie; Anand, Madhur

    2014-01-01

    The role of forest plantations in biodiversity conservation has gained more attention in recent years. However, most work on evaluating the diversity of forest plantations focuses only on one spatial scale; thus, we examined the effects of sampling scale on diversity in forest plantations. We designed a hierarchical sampling strategy to collect data on woody species diversity in planted pine (Pinus tabuliformis Carr.), planted larch (Larix principis-rupprechtii Mayr.), and natural secondary deciduous broadleaf forests in a mountainous region of Beijing, China. Additive diversity partition analysis showed that, compared to natural forests, the planted pine forests had a different woody species diversity partitioning pattern at multi-scales (except the Simpson diversity in the regeneration layer), while the larch plantations did not show multi-scale diversity partitioning patterns that were obviously different from those in the natural secondary broadleaf forest. Compare to the natural secondary broadleaf forests, the effects of planted pine forests on woody species diversity are dependent on the sampling scale and layers selected for analysis. Diversity in the planted larch forest, however, was not significantly different from that in the natural forest for all diversity components at all sampling levels. Our work demonstrated that the species selected for afforestation and the sampling scales selected for data analysis alter the conclusions on the levels of diversity supported by plantations. We suggest that a wide range of scales should be considered in the evaluation of the role of forest plantations on biodiversity conservation.

  13. Recent changes in glacial area and volume on Tuanjiefeng peak region of Qilian Mountains, China.

    PubMed

    Xu, Junli; Liu, Shiyin; Zhang, Shiqiang; Guo, Wanqin; Wang, Jian

    2013-01-01

    Glaciers' runoff in the Qilian Mountains serves as a critical water resource in the northern sections of the Gansu province, the northeastern sections of the Qinghai province, and the northeastern fringe of the Tibetan Plateau. Changes in the glacial area and volume around the highest peak of the Qilian Mountains, i.e., Tuanjiefeng Peak, were estimated using multi-temporal remote-sensing images and digital elevation models, and all possible sources of uncertainty were considered in detail. The total glacier area decreased by 16.1±6.34 km(2) (9.9±3.9%) during 1966 to 2010. The average annual glacier shrinkage was -0.15% a(-1) from 1966 to 1995, -0.61% a(-1) from 1995 to 2000, -0.20% a(-1) from 2000 to 2006, and -0.45% a(-1) from 2006 to 2010. A comparison of glacier surface elevations using digital elevation models derived from topographic maps in 1966 and from the Shuttle Radar Topography Mission in 1999 suggests that 65% of the grid cells has decreased, thereby indicating that the glacier thickness has declined. The average change in glacier thickness was -7.3±1.5 m (-0.21±0.04 m·a(-1)) from 1966 to 1999. Glaciers with northeastern aspects thinned by 8.3±1.4 m from 1966 to 1999, i.e., almost twice as much as those with southwestern aspects (4.3±1.3 m). The ice volume decreased by 11.72±2.38×10(8) m(3) from 1966 to 1999, which was about 17.4% more than the value calculated from the statistical relationship between glacier area and volume. The relationship between glacier area change and elevation zone indicates that glacier change is not only dominated by climate change but also affected by glacier dynamics, which are related to local topography. The varied response of a single glacier to climate change indicates that the glacier area change scheme used in some models must be improved. PMID:24015174

  14. Recent Changes in Glacial Area and Volume on Tuanjiefeng Peak Region of Qilian Mountains, China

    PubMed Central

    Xu, Junli; Liu, Shiyin; Zhang, Shiqiang; Guo, Wanqin; Wang, Jian

    2013-01-01

    Glaciers' runoff in the Qilian Mountains serves as a critical water resource in the northern sections of the Gansu province, the northeastern sections of the Qinghai province, and the northeastern fringe of the Tibetan Plateau. Changes in the glacial area and volume around the highest peak of the Qilian Mountains, i.e., Tuanjiefeng Peak, were estimated using multi-temporal remote-sensing images and digital elevation models, and all possible sources of uncertainty were considered in detail. The total glacier area decreased by 16.1±6.34 km2 (9.9±3.9%) during 1966 to 2010. The average annual glacier shrinkage was −0.15% a−1 from 1966 to 1995, −0.61% a−1 from 1995 to 2000, −0.20% a−1 from 2000 to 2006, and −0.45% a−1 from 2006 to 2010. A comparison of glacier surface elevations using digital elevation models derived from topographic maps in 1966 and from the Shuttle Radar Topography Mission in 1999 suggests that 65% of the grid cells has decreased, thereby indicating that the glacier thickness has declined. The average change in glacier thickness was −7.3±1.5 m (−0.21±0.04 m·a−1) from 1966 to 1999. Glaciers with northeastern aspects thinned by 8.3±1.4 m from 1966 to 1999, i.e., almost twice as much as those with southwestern aspects (4.3±1.3 m). The ice volume decreased by 11.72±2.38×108 m3 from 1966 to 1999, which was about 17.4% more than the value calculated from the statistical relationship between glacier area and volume. The relationship between glacier area change and elevation zone indicates that glacier change is not only dominated by climate change but also affected by glacier dynamics, which are related to local topography. The varied response of a single glacier to climate change indicates that the glacier area change scheme used in some models must be improved. PMID:24015174

  15. [Present situation of rice fertilization in qin-ba mountainous area of Southern Shaanxi, China].

    PubMed

    Wang, Xiao-Ying; Liu, Fen; Tong, Yan-An; Zhao, Zuo-Ping

    2013-11-01

    In order to understand the present situation of rice fertilization and the existing problems in the farmers' nutrient resources input in the Qin-Ba mountainous area of southern Shaanxi, the survey data from 2854 households in 11 counties of this area in the project "soil testing and formulated fertilization in 2006-2009" were analyzed and evaluated, and the countermeasures for the existing problems in the farmers' nutrient resources input were proposed. In the study area, the average rice yield was 7822 kg x hm(-2) per year, and the ratio of the households obtained the medium level yield was up to 50.9%. The input of the total fertilizers N, P2O5, K2O was 169, 68, and 54 kg x hm(-2), and the chemical fertilizer rate was 159, 62, and 45 kg x hm(-2), with the partial factor productivity (PFP) of the N, P2O5, and K2O being 51.52, 135.69, and 158.26 kg x kg(-1), respectively. According to the nutrient fertilization level, the proportion of the households fertilized with rational level of chemical N, P2O5, and K2O occupied 48.0%, 42.4%, and 7.2%, that of the households fertilized with excessive level was 22.6%, 11.2%, and 0.6%, and the proportion of the households fertilized with insufficient level occupied 29.4%, 46.5%, and 92.2%, respectively. The rice yield in the Qin-Ba mountainous area could be increased by 77 thousand tons if the households fertilizing with insufficient level of chemical NPK fertilizers increased the fertilization rate to a rational level. The existing problems in the farmers' nutrient resources input were mainly the coexistence of excessive and insufficient application of nitrogen and phosphate fertilizers and the insufficient input of potassium fertilizer and organic manure. In the rice fertilization in this area, the focus would be the balanced application of nitrogen and phosphate fertilizers, the increase of the fertilization rates of potassium fertilizer and organic manure, and the increase of top dressing, especially potassium.

  16. [Forest recovery state in wind disaster area of Changbai Mountains, Northeast China].

    PubMed

    Guo, Li-Ping; Ji, Lan-Zhu; Zhang, Wei-Dong; Zhang, Yue; Xue, Jun-Gang

    2010-06-01

    Based on the field investigation in windfall areas of Changbai Mountains, this paper studied the community recovery characteristics of broad-leaved Korean pine forest (BKPF), spruce fir forest (SFF), and Erman's birch forest (EBF) that were disturbed by wind disaster 23 years ago. The recovery rate of these three forest types was in the order of BKPF > SFF > EBF, and their total community index was 0.49, 0.44, and 0.33, respectively. The effects of the wind disaster on the forest tree species composition and diversity were different. In BKPF, the total number of trees increased significantly, but the tree species number and alpha diversity index had no significant change; in SFF, only the Shannon diversity index and Simpson dominance index decreased significantly; while in EBF, all diversity indices except Pielou evenness index had significant decrease. The responses of dominance tree composition and regeneration to the wind disaster depended on forest types. Comparing with the plots not suffered from wind disaster, the BKPF under wind disaster disturbance had greatly different dominance tree compositions, but the difference in both SFF and EBF was not significant. The BKPF's sapling regeneration was fairly good, while the SFF's was small, and EBF almost had no sapling regeneration. All the results suggested that the effects of wind disaster disturbance on the test forest ecosystems in study areas was not removed even after 23 years, and the recovery of forest after wind disaster disturbance needs a relatively long time.

  17. [Fine root biomass of four main vegetation types in Daluo Mountain of Ningxia, Northwest China].

    PubMed

    Su, Ji-Shuai; Cheng, Ji-Min; Gao, Yang; Qiu, Zhi-Hu; Cao, Huai-qing

    2013-03-01

    By the method of soil core sampling, this paper studied the fine root biomass, soil water content, and soil bulk density in 0-40 cm soil layer of four main vegetation types (Picea crassifolia forest, Pinus tabulaeformis forest, deciduous shrubs, and desert grassland) in Daluo Mountain of Ningxia, and the fine root biomass in the 0-40 cm soil layer of P. crassifolia forests with the ages of 50-, 70-, and 100 a. The fine root biomass of the four vegetation types was mainly distributed in 0-20 cm soil layer, with the rank of P. tabulaeformis forest > P. crassifolia forest > deciduous shrubs > desert grassland, and the fine root biomass of P. tabulaeformis forest was significantly higher than that of the other three vegetation types. The fine root biomass of the P. crassifolia forests with different ages was 70 a > 100 a > 50 a, and there were no significant differences in the live fine root biomass ratio and dead fine root biomass ratio among the three P. crassifolia forests. The soil water content in the 0-40 cm soil layer of the four vegetation types was P. crassifolia forest > P. tabulaeformis forest > deciduous shrubs > desert grassland, while the soil bulk density followed an opposite pattern, and was significantly negatively correlated with the fine root biomass.

  18. Yalongjiang River Has Had an Important Role in the Dispersal and Divergence of Rosa soulieana in the Hengduan Mountains of China

    PubMed Central

    Jian, Hongying; Zhang, Yonghong; Qiu, Xianqin; Yan, Huijun; Wang, Qigang; Zhang, Hao; Sun, Hang

    2016-01-01

    The Hengduan Mountains are the core of the Sino-Himalayan Floristic Region. Rosa soulieana Crép. is an important wild rose species that is widely distributed in the Hengduan Mountains. To provide better future utilization of this wild rose, and also to add some possible proof of the effect of geomorphological and ecological characteristics of the Hengduan Mountains on the current spatial distribution and genetic diversity of local species, the genetic diversity and genetic structure of 556 individuals from 37 populations of R. soulieana were studied using fluorescent amplified fragment length polymorphisms (AFLPs). R. soulieana showed a moderately high level of genetic diversity and a high level of genetic differentiation at the species level. The total percentage of polymorphic loci, total heterozygosity (Ht), Shannon index (I), and heterozygosity value within populations (Hs) were 97.8%, 0.253, 0.339, and 0.139, respectively. More than half of the total genetic variation (54.0%) occurred within populations, and the overall gene differentiation coefficient (Gst) was 0.451. The genetic differentiation among populations was positively and significantly correlated with geographic distance. The neighbor-joining cluster and the Bayesian analysis divided all the populations and individuals into 3 groups, and did not support the morphology based intraspecific varieties. The results confirmed that the ancient R. soulieana of the third group survived in northwestern Yunnan and Yalongjiang valley and then moved upnorth along the valley. The spatial distribution of the other two groups was the result of allopatric divergence due to long period of adaptation to the different climatic conditions of its distribution at either side of the Yalongjiang River. PMID:27355209

  19. Yalongjiang River Has Had an Important Role in the Dispersal and Divergence of Rosa soulieana in the Hengduan Mountains of China.

    PubMed

    Jian, Hongying; Zhang, Yonghong; Qiu, Xianqin; Yan, Huijun; Wang, Qigang; Zhang, Hao; Sun, Hang

    2016-01-01

    The Hengduan Mountains are the core of the Sino-Himalayan Floristic Region. Rosa soulieana Crép. is an important wild rose species that is widely distributed in the Hengduan Mountains. To provide better future utilization of this wild rose, and also to add some possible proof of the effect of geomorphological and ecological characteristics of the Hengduan Mountains on the current spatial distribution and genetic diversity of local species, the genetic diversity and genetic structure of 556 individuals from 37 populations of R. soulieana were studied using fluorescent amplified fragment length polymorphisms (AFLPs). R. soulieana showed a moderately high level of genetic diversity and a high level of genetic differentiation at the species level. The total percentage of polymorphic loci, total heterozygosity (Ht), Shannon index (I), and heterozygosity value within populations (Hs) were 97.8%, 0.253, 0.339, and 0.139, respectively. More than half of the total genetic variation (54.0%) occurred within populations, and the overall gene differentiation coefficient (Gst) was 0.451. The genetic differentiation among populations was positively and significantly correlated with geographic distance. The neighbor-joining cluster and the Bayesian analysis divided all the populations and individuals into 3 groups, and did not support the morphology based intraspecific varieties. The results confirmed that the ancient R. soulieana of the third group survived in northwestern Yunnan and Yalongjiang valley and then moved upnorth along the valley. The spatial distribution of the other two groups was the result of allopatric divergence due to long period of adaptation to the different climatic conditions of its distribution at either side of the Yalongjiang River. PMID:27355209

  20. Yalongjiang River Has Had an Important Role in the Dispersal and Divergence of Rosa soulieana in the Hengduan Mountains of China.

    PubMed

    Jian, Hongying; Zhang, Yonghong; Qiu, Xianqin; Yan, Huijun; Wang, Qigang; Zhang, Hao; Sun, Hang

    2016-01-01

    The Hengduan Mountains are the core of the Sino-Himalayan Floristic Region. Rosa soulieana Crép. is an important wild rose species that is widely distributed in the Hengduan Mountains. To provide better future utilization of this wild rose, and also to add some possible proof of the effect of geomorphological and ecological characteristics of the Hengduan Mountains on the current spatial distribution and genetic diversity of local species, the genetic diversity and genetic structure of 556 individuals from 37 populations of R. soulieana were studied using fluorescent amplified fragment length polymorphisms (AFLPs). R. soulieana showed a moderately high level of genetic diversity and a high level of genetic differentiation at the species level. The total percentage of polymorphic loci, total heterozygosity (Ht), Shannon index (I), and heterozygosity value within populations (Hs) were 97.8%, 0.253, 0.339, and 0.139, respectively. More than half of the total genetic variation (54.0%) occurred within populations, and the overall gene differentiation coefficient (Gst) was 0.451. The genetic differentiation among populations was positively and significantly correlated with geographic distance. The neighbor-joining cluster and the Bayesian analysis divided all the populations and individuals into 3 groups, and did not support the morphology based intraspecific varieties. The results confirmed that the ancient R. soulieana of the third group survived in northwestern Yunnan and Yalongjiang valley and then moved upnorth along the valley. The spatial distribution of the other two groups was the result of allopatric divergence due to long period of adaptation to the different climatic conditions of its distribution at either side of the Yalongjiang River.

  1. Arsenic-contaminated cold-spring water in mountainous areas of Hui County, Northwest China: a new source of arsenic exposure.

    PubMed

    Zhang, Qiang; Zheng, Quanmei; Sun, Guifan

    2011-11-15

    Although pump-well is the primary drinking water source in rural areas of China, there are still 8.4% of villages reliant on cold-spring. In this study, a survey of arsenic concentration in cold-springs and pump-wells was carried out in Hui County, Northwest China. A total of 352 drinking water samples, including 177 cold-springs and 175 pump-wells, were collected. The maximum arsenic concentrations in cold-springs and pump-wells were 0.482 mg/L and 0.067 mg/L, respectively. We found that 15.8% (28) of total cold-springs and 1.1% (2) of total pump-wells had arsenic concentrations exceeding the maximum allowable concentration of arsenic in drinking water of rural China (0.05 mg/L). Our findings show that 5 cold spring-contaminated villages are located in the mountainous areas of Hui County and 2224 inhabitants may be at risk of high arsenic exposure. This paper indicates that arsenic contamination of cold-springs may be more serious than expected in mountainous areas of Northwest China and extensive surveys and epidemiological studies should be carried out to investigate the potential contaminated areas and affected population.

  2. Gold deposits in the Xiaoqinling-Xiong'ershan region, Qinling mountains, central China

    USGS Publications Warehouse

    Mao, J.; Goldfarb, R.J.; Zhang, Z.; Xu, W.; Qiu, Y.; Deng, J.

    2002-01-01

    The gold-rich Xiaoqinling-Xiong'ershan region in eastern Shaanxi and western Henan provinces, central China, lies about 30-50 km inland of the southern margin of the North China craton. More than 100 gold deposits and occurrences are concentrated in the Xiaoqinling (west), Xiaoshan (middle), and Xiong'ershan (east) areas. Late Archean gneiss of the Taihua Group, and Middle Proterozoic metavolcanic rocks of the Xiong'er Group are the main host rocks for the deposits. Mesozoic granitoids (ca. 178-104 Ma) are present in most gold districts, but deposits are typically hosted in the Precambrian basement rocks hundreds of meters to as far as 10 km from the intrusions and related hornfels zones. Deposits in the Xiaoqinling and Xiaoshan areas are best classified as orogenic gold deposits, with ores occurring in a number of distinct belts both in quartz veins and disseminated in altered metamorphic rocks. Alteration assemblages are dominated by quartz, sericite, pyrite, and carbonate minerals. The ore-forming fluids were low salinity, CO2-rich, and characterized by isotopically heavy ??18O. Four deposits (Dongchuang, Wenyu, Yangzhaiyu, and Dahu) in the Xiaoqinling area each contain resources of about 1 Moz Au. Some of the gold deposits in the Xiong'ershan area represent more shallowly emplaced tellurium-enriched orogenic systems, which include resources of approximately 1-1.5 Moz Au at Shanggong and Beiling (or Tantou). Others are epithermal deposits (e.g., Qiyugou and Dianfang) that are hosted in volcanic breccia pipes. Isotopic dates for all gold deposits, although often contradictory, generally cluster between 172-99 Ma and are coeval with emplacement of the post-kinematic granitoids. The gold deposits formed during a period of relaxation of far-field compressional stresses, clearly subsequent to the extensive Paleozoic-early Mesozoic accretion of are terranes and the Yangtze craton onto the southern margin of the North China craton. Hydrothermal and magmatic events

  3. Flying over Pluto’s icy plains and Hillary Mountains

    NASA Video Gallery

    This simulated flyover of two regions on Pluto, northwestern Sputnik Planum (Sputnik Plain) and Hillary Montes (Hillary Mountains), was created from New Horizons close-approach images. Sputnik Plan...

  4. Factors influencing the transmission of Schistosoma japonicum in the mountains of Sichuan Province of China.

    PubMed

    Spear, Robert C; Seto, Edmund; Liang, Song; Birkner, Merrill; Hubbard, Alan; Qiu, Dongchuan; Yang, Changhong; Zhong, Bo; Xu, Fashen; Gu, Xueguang; Davis, George M

    2004-01-01

    Twenty villages in the Anning River Valley of southwestern Sichuan China were surveyed for Schistosoma japonicum infections in humans and domestic animals. Also surveyed were human water contact patterns, snail populations, cercarial risk in irrigation systems, and agricultural land use. Few animals were infected, while village prevalence of infection in humans ranged from 3% to 68% and average village eggs per gram of stool ranged from 0 to 110. Except for occupation and education, individual characteristics were not strong determinants of infection intensity within a village. Differences in human infection intensity between these villages are strongly associated with crop type, with low-intensity villages principally growing rice, in contrast to villages devoting more land to vegetables and tobacco. Cercarial risk in village irrigation systems is associated with snail density and human infection intensity through the use of manure-based fertilizer. Some of the agricultural and environmental factors associated with infection risk can be quantified using remote sensing technology.

  5. Primary Succession of Nitrogen Cycling Microbial Communities Along the Deglaciated Forelands of Tianshan Mountain, China.

    PubMed

    Zeng, Jun; Lou, Kai; Zhang, Cui-Jing; Wang, Jun-Tao; Hu, Hang-Wei; Shen, Ju-Pei; Zhang, Li-Mei; Han, Li-Li; Zhang, Tao; Lin, Qin; Chalk, Phillip M; He, Ji-Zheng

    2016-01-01

    Structural succession and its driving factors for nitrogen (N) cycling microbial communities during the early stages of soil development (0-44 years) were studied along a chronosequence in the glacial forelands of the Tianshan Mountain No.1 glacier in the arid and semi-arid region of central Asia. We assessed the abundance and population of functional genes affiliated with N-fixation (nifH), nitrification (bacterial and archaeal amoA), and denitrification (nirK/S and nosZ) in a glacier foreland using molecular methods. The abundance of functional genes significantly increased with soil development. N cycling community compositions were also significantly shifted within 44 years and were structured by successional age. Cyanobacterial nifH gene sequences were the most dominant N fixing bacteria and its relative abundance increased from 56.8-93.2% along the chronosequence. Ammonia-oxidizing communities shifted from the Nitrososphaera cluster (AOA-amoA) and the Nitrosospira cluster ME (AOB-aomA) in younger soils (0 and 5 years) to communities dominated by soil and sediment 1 (AOA-amoA) and Nitrosospira Cluster 2 Related (AOB-aomA) in older soils (≥17 years). Most of the denitrifers closest relatives were potential aerobic denitrifying bacteria, and some other types of denitrifying bacteria (like autotrophic nitrate-reducing, sulfide-oxidizing bacteria and denitrifying phosphorus removing bacteria) were also detected in all soil samples. The regression analysis showed that N cycling microbial communities were dominant in younger soils (0-5 years) and significantly correlated with soil total carbon, while communities that were most abundant in older soils were significantly correlated with soil total nitrogen. These results suggested that the shift of soil C and N contents during the glacial retreat significantly influenced the abundance, composition and diversity of N cycling microbial communities. PMID:27625641

  6. Primary Succession of Nitrogen Cycling Microbial Communities Along the Deglaciated Forelands of Tianshan Mountain, China

    PubMed Central

    Zeng, Jun; Lou, Kai; Zhang, Cui-Jing; Wang, Jun-Tao; Hu, Hang-Wei; Shen, Ju-Pei; Zhang, Li-Mei; Han, Li-Li; Zhang, Tao; Lin, Qin; Chalk, Phillip M.; He, Ji-Zheng

    2016-01-01

    Structural succession and its driving factors for nitrogen (N) cycling microbial communities during the early stages of soil development (0–44 years) were studied along a chronosequence in the glacial forelands of the Tianshan Mountain No.1 glacier in the arid and semi-arid region of central Asia. We assessed the abundance and population of functional genes affiliated with N-fixation (nifH), nitrification (bacterial and archaeal amoA), and denitrification (nirK/S and nosZ) in a glacier foreland using molecular methods. The abundance of functional genes significantly increased with soil development. N cycling community compositions were also significantly shifted within 44 years and were structured by successional age. Cyanobacterial nifH gene sequences were the most dominant N fixing bacteria and its relative abundance increased from 56.8–93.2% along the chronosequence. Ammonia-oxidizing communities shifted from the Nitrososphaera cluster (AOA-amoA) and the Nitrosospira cluster ME (AOB-aomA) in younger soils (0 and 5 years) to communities dominated by soil and sediment 1 (AOA-amoA) and Nitrosospira Cluster 2 Related (AOB-aomA) in older soils (≥17 years). Most of the denitrifers closest relatives were potential aerobic denitrifying bacteria, and some other types of denitrifying bacteria (like autotrophic nitrate-reducing, sulfide-oxidizing bacteria and denitrifying phosphorus removing bacteria) were also detected in all soil samples. The regression analysis showed that N cycling microbial communities were dominant in younger soils (0–5 years) and significantly correlated with soil total carbon, while communities that were most abundant in older soils were significantly correlated with soil total nitrogen. These results suggested that the shift of soil C and N contents during the glacial retreat significantly influenced the abundance, composition and diversity of N cycling microbial communities. PMID:27625641

  7. [Evapotranspiration characteristics of artificial and natural forests in Liupan Mountains of Ningxia, China during growth season].

    PubMed

    Cao, Gong-xiang; Wang, Xu-fang; Xiong, Wei; Wang, Yan-hui; Yu, Peng-tao; Wang, Yun-ni; Xu, Li-hong; Li, Zhen-hua

    2013-08-01

    In order to understand the effects of the structure of forest ecosystem on the hydrological processes, a comparative study by using thermal dissipation technique and hydrological methodology was made on the evapotranspiration (ET) and its components of Larix principis-rupprechtii plantation and Pinus armandi natural forest in two adjacent stands in a small catchment Xiangshuihe of Liupan Mountains during the growth season (May-October) in 2009. Throughout the growth season, the total ET from the plantation was 518.2 mm, which accounted for 104.6% of the precipitation and was much higher than that (420.5 mm) of the natural forest. The allocation of ET in the vertical layers performed similarly between the two stands, with the order of canopy layer > herb and soil layer > shrub layer, but the ratio of each component to total ET differed significantly. The plantation consumed 0.2 and 0.9 times more water for canopy interception (19.6 mm per month) and tree transpiration (25.2 mm per month) than the natural forest, respectively. However, the transpiration from the plantation was 4.4 mm per month, and took up 23.4% of the natural forest. In contrast, the sum of soil evaporation and herbage evapotranspiration consumed 37.1 mm water per month in the plantation, which was 0.8 times higher than that in the natural forest. The ET was calculated by Penman-Monteith equation to compare the results estimated by sap flow measurements, and the values estimated by the two methods were similar. PMID:24380324

  8. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  9. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China

    PubMed Central

    Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3−-N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  10. [Evapotranspiration characteristics of artificial and natural forests in Liupan Mountains of Ningxia, China during growth season].

    PubMed

    Cao, Gong-xiang; Wang, Xu-fang; Xiong, Wei; Wang, Yan-hui; Yu, Peng-tao; Wang, Yun-ni; Xu, Li-hong; Li, Zhen-hua

    2013-08-01

    In order to understand the effects of the structure of forest ecosystem on the hydrological processes, a comparative study by using thermal dissipation technique and hydrological methodology was made on the evapotranspiration (ET) and its components of Larix principis-rupprechtii plantation and Pinus armandi natural forest in two adjacent stands in a small catchment Xiangshuihe of Liupan Mountains during the growth season (May-October) in 2009. Throughout the growth season, the total ET from the plantation was 518.2 mm, which accounted for 104.6% of the precipitation and was much higher than that (420.5 mm) of the natural forest. The allocation of ET in the vertical layers performed similarly between the two stands, with the order of canopy layer > herb and soil layer > shrub layer, but the ratio of each component to total ET differed significantly. The plantation consumed 0.2 and 0.9 times more water for canopy interception (19.6 mm per month) and tree transpiration (25.2 mm per month) than the natural forest, respectively. However, the transpiration from the plantation was 4.4 mm per month, and took up 23.4% of the natural forest. In contrast, the sum of soil evaporation and herbage evapotranspiration consumed 37.1 mm water per month in the plantation, which was 0.8 times higher than that in the natural forest. The ET was calculated by Penman-Monteith equation to compare the results estimated by sap flow measurements, and the values estimated by the two methods were similar.

  11. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  12. Primary Succession of Nitrogen Cycling Microbial Communities Along the Deglaciated Forelands of Tianshan Mountain, China

    PubMed Central

    Zeng, Jun; Lou, Kai; Zhang, Cui-Jing; Wang, Jun-Tao; Hu, Hang-Wei; Shen, Ju-Pei; Zhang, Li-Mei; Han, Li-Li; Zhang, Tao; Lin, Qin; Chalk, Phillip M.; He, Ji-Zheng

    2016-01-01

    Structural succession and its driving factors for nitrogen (N) cycling microbial communities during the early stages of soil development (0–44 years) were studied along a chronosequence in the glacial forelands of the Tianshan Mountain No.1 glacier in the arid and semi-arid region of central Asia. We assessed the abundance and population of functional genes affiliated with N-fixation (nifH), nitrification (bacterial and archaeal amoA), and denitrification (nirK/S and nosZ) in a glacier foreland using molecular methods. The abundance of functional genes significantly increased with soil development. N cycling community compositions were also significantly shifted within 44 years and were structured by successional age. Cyanobacterial nifH gene sequences were the most dominant N fixing bacteria and its relative abundance increased from 56.8–93.2% along the chronosequence. Ammonia-oxidizing communities shifted from the Nitrososphaera cluster (AOA-amoA) and the Nitrosospira cluster ME (AOB-aomA) in younger soils (0 and 5 years) to communities dominated by soil and sediment 1 (AOA-amoA) and Nitrosospira Cluster 2 Related (AOB-aomA) in older soils (≥17 years). Most of the denitrifers closest relatives were potential aerobic denitrifying bacteria, and some other types of denitrifying bacteria (like autotrophic nitrate-reducing, sulfide-oxidizing bacteria and denitrifying phosphorus removing bacteria) were also detected in all soil samples. The regression analysis showed that N cycling microbial communities were dominant in younger soils (0–5 years) and significantly correlated with soil total carbon, while communities that were most abundant in older soils were significantly correlated with soil total nitrogen. These results suggested that the shift of soil C and N contents during the glacial retreat significantly influenced the abundance, composition and diversity of N cycling microbial communities.

  13. [Carbon density and production in valley spruce-fir forest in Xiaoxing'an Mountains, China].

    PubMed

    Cai, Hui-Ying; Di, Xue-Ying; Jin, Guang-Ze

    2014-10-01

    The carbon density and production were measured using both forest inventory and allometry approaches in the declining valley spruce-fir forest in Xiaoxing' an Mountains. Results showed that the total carbon density of the forest was 268. 14 t C · hm(-2) in 2011, and carbon densities of the vegetation, detritus and soil were 74.25, 16.86 and 177.03 t C · hm(-2), respectively. From 2006 to 2011, tree layer carbon density decreased from 80.86 t C · hm(-2) to 71.73 t C · hm(-2). The average decrease proportions per year of carbon density were 0.5%, 1.2%, 2.7% and 3.7% for Abies nephrolepis, Betula platyphylla, Picea spp., and Larix gmelinii, respectively. However, carbon densities were increased by 2.9%, 3.9% and 7.2% per year for Alnus sibirica, Pinus koraiensis and Acer ukurunduense, respectively. Net primary production (NPP) of the forest was 4.69 t C · hm(-2) · a(-1). The ratio of belowground NPP to aboveground NPP was 0.56. Litterfall accounted for the largest proportion of the NPP of forest with a value of 34.5%. As the two most important carbon output approaches of forest ecosystems, the fluxes of heterotrophic respiration and coarse woody debris decomposition were 293.67 and 119.29 g C · m(-2) · a(-1), respectively. Net ecosystem production (NEP) of the forest was 55.90 g C · m(-2) a(-1). The results indicated that the valley spruce-fir forest in the declining state still had a certain carbon sink capacity.

  14. Temperature sensitivity of soil carbon dioxide and nitrous oxide emissions in mountain forest and meadow ecosystems in China

    NASA Astrophysics Data System (ADS)

    Zhang, Junjun; Peng, Changhui; Zhu, Qiuan; Xue, Wei; Shen, Yan; Yang, Yanzheng; Shi, Guohua; Shi, Shengwei; Wang, Meng

    2016-10-01

    An incubation experiment was conducted at three temperature levels (8, 18 and 28 °C) to quantify the response of soil CO2 and N2O emissions to temperature in three ecosystems (pine forest, oak forest, and meadow) located in the Qinling Mountains of China, which are considered to be susceptible to disturbance and climate changes, especially global warming. The soil CO2 emission rates increased with temperature and decreased with soil depth; they were the highest in the oak forest (broadleaf forest) and were lower in the pine forest (coniferous forest) and the meadow ecosystem. However, there was no significant difference in the soil N2O emission rates among the three ecosystems. The temperature sensitivity of CO2 and N2O was higher in the forest than in the meadow ecosystem. The Q10 values (temperature sensitivity coefficient) for CO2 and N2O were 1.07-2.25 and 0.82-1.22, respectively, for the three ecosystems. There was also evidence that the CO2 and N2O emission rates were positively correlated. The soil characteristics exhibited different effects on CO2 and N2O emissions among different ecosystems at the three temperature levels. Moreover, the soil dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA) and nitrate (NO3-) were important factors for CO2 emissions, whereas the soil ammonium (NH4+) and pH were the major controllers of N2O emissions. Unexpectedly, our results indicated that CO2 emissions are more sensitive to increasing temperature than N2O, noting the different feedback of CO2 and N2O emissions to global warming in this region. The different responses of greenhouse gas emissions in different forest types and a meadow ecosystem suggest that it is critical to conduct a comprehensive investigation of the complex mountain forest and meadow ecosystem in the transitional climate zone under global warming. Our research results provide new insight and advanced understanding of the variations in major greenhouse gas emissions (CO2 and N2O

  15. Leaf-rolling sawflies (Hymenoptera, Pamphiliidae, Pamphiliinae) of Tianmushan Mountains, Zhejiang Province, China.

    PubMed

    Shinohara, Akihiko; Wei, Mei-Cai

    2016-01-01

    Two species of Neurotoma, six species of Onycholyda, and five species of Pamphilius are recorded from Tianmushan, Zhejiang Province, China, and a key is given to these three genera and 13 species. Three new species, Onycholyda atra Shinohara & Wei, sp. nov. from Zhejiang Province, O. fulvicornis Shinohara, sp. nov. from Shaanxi Province and Zhejiang Province, and Pamphilius padus Shinohara, sp. nov. from Zhejiang Province, are described. New distribution records are: Onycholyda shaanxiana Shinohara, 1999, from Hubei Province, Zhejiang Province and Guangxi Zhuang Autonomous Region, O. subquadrata (Maa, 1944) from Zhejiang Province, O. tianmushana Shinohara & Xiao, 2006, from Hunan Province and Jiangxi Province, Pamphilius palliceps Shinohara & Xiao, 2006, from Anhui Province, P. lizejiani Shinohara in Shinohara & Wei, 2012, from Zhejiang Province, P. shengi Wei in Wei & Xiao, 1999, from Hubei Province and Zhejiang Province, and P. qinlingicus Wei in Wu & Wei, 2010, from Zhejiang Province. The larva of P. padus feeds on Padus obtusata (Rosaceae) and that of P. palliceps feeds on Rosa multiflora (Rosaceae), both singly making a leaf-roll. Rubus peltatus (Rosaceae) is recorded as a host plant of O. atra based on the observation of oviposition. PMID:27395926

  16. Spatial patterns of (137)Cs inventories and soil erosion from earth-banked terraces in the Yimeng Mountains, China.

    PubMed

    Zhang, Yunqi; Long, Yi; An, Juan; Yu, Xingxiu; Wang, Xiaoli

    2014-10-01

    The Yimeng Mountains is one of China's most susceptible regions to soil erosion. In this region, slopes are composed of granite- or gneiss-derived soils that are commonly cultivated using earth-banked terraces. Based on the (137)Cs measurement for nine reference cores, the present study analysed the spatial patterns of (137)Cs inventory and soil erosion using 105 sampling points in a seven-level earth-banked terrace system. The mean (137)Cs inventory, standard deviation, coefficient of variation, and allowable error for the nine reference cores were 987 Bq m(-2), 71 Bq m(-2), 7%, and 6%, respectively, values that may reflect the heterogeneity of the initial (137)Cs fallout deposit. Within each terrace, the (137)Cs inventory generally increases from the rear edge to the front edge, accompanied by a decrease in the erosion rate. This results from planation by tillage and rainfall runoff during the development of the earth-banked terraces. Across the entire seven-level terrace system, (137)Cs inventories decrease from the highest terrace downwards, but increase in the lower terraces, whereas erosion rate displays the opposite trend. These trends are the result of the combined effects of the earth-bank segmented hillslope, the limited protection of the earth banks, and rainfall runoff in combination with tillage. The high coefficients of variation of (137)Cs inventories for the 21 sampling rows, with a mean value of 44%, demonstrate the combined effects of variations in original microtopography, anthropogenic disturbance, the incohesive soils weathered from underlying granite, and the warm climate. Although earth-banked terraces can reduce soil erosion to some extent, the estimated erosion rates for the study area are still very high. PMID:24844614

  17. Variations in Soil Microbial Communities and Residues Along an Altitude Gradient on the Northern Slope of Changbai Mountain, China

    PubMed Central

    Zhang, Bin; Liang, Chao; He, Hongbo; Zhang, Xudong

    2013-01-01

    Altitudinally-defined climate conditions provide specific vegetation types and soil environments that could influence soil microbial communities, which in turn may affect microbial residues. However, the knowledge is limited in terms of the degree to which microbial communities and residues present and differ along altitude. In this study, we examined the soil microbial communities and residues along the northern slope of Changbai Mountain, China using phospholipid fatty acid (PLFA) and amino sugar analysis, respectively. Soil samples were taken from five different vegetation belts defined by climates. Principal component analysis (PCA) revealed substantial differences in soil microbial community composition among study sites, appeared to be driven primarily by soil pH and C/N ratio on the first principal component (PC1) which accounted for 50.7% of the total sample variance. The alpine tundra was separated from forest sites on the second principal component (PC2) by a signifiscantly higher amount of fungal PLFA (18:2ω6,9). Soil pH and C/N ratio were also correlated with the ratios of Gram-positive to Gram-negative bacteria (Gm+/Gm−), glucosamine to galactosamine (GluN/GalN), and glucosamine to muramic acid (GluN/MurA). Both total PLFAs and amino sugars were positively correlated with soil organic carbon, inorganic nitrogen, available phosphorus and potassium. We concluded that soil pH and C/N ratio were the most important drivers for microbial community structure and amino sugar pattern, while substrate availability was of great importance in determining the concentrations of microbial communities and residues. These findings could be used to facilitate interpretation of soil microbial community and amino sugar data derived from measurements in latitude or managed forests. PMID:23776630

  18. [Spatial point pattern analysis of Abies georgei var. smithii in forest of Sygera Mountains in southeast Tibet, China].

    PubMed

    Xie, Chuan-qi; Tian, Min-xia; Zhao, Zhong-rui; Zheng, Wei-lie; Wang, Guo-yan

    2015-06-01

    In this study, based on a 4 hm2 stem-mapping plot, we analyzed spatial distributions of Abies georgei var. smithii, the dominant species in forest of Sygera Mountains in southeast Tibet, China. Pair-correlation function was used to characterize univariate spatial point patterns of three size classes of the population and bivariate spatial patterns between those and different sizes of dead wood. A. georgei var. smithii population was characterized by reverse J-shaped DBH distribution, indicating an increasing population. Saplings of the population were spatially obviously aggregated at the small scales (0-7 m), and mid-sized trees and large-sized trees of the population were randomly or uniformly distributed. The aggregation intensities of A. georgei var. smithii decreased with the increasing diameter classes and spatial scales. Saplings and mid-sized trees were significantly and negatively associated with large-sized trees at the small scales (0-35 and 0-30 m), but the associations reversed at the large scales (45-100 and 80-100 m). In addition, with the increasing age difference between diameter classes of the population, the intensities of positive or negative correlations increased. Spatial associations between saplings and dead large-sized trees, and between mid-sized trees and dead large-sized trees were negative at the small scales (0-34 and 5-27 m), but positive at the large scales (49-100 and 73-100 m). This suggested that released niche space due to dead large-sized trees is not enough to weaken their negative impacts on saplings. We concluded that self-thinning effect and Janzen-Connell hypothesis may be the main mechanisms for the spatial pattern formation of A. georgei var. smithii population. PMID:26572011

  19. Non-invasive determination of the immune physiological state of reindeer (Rangifer tarandus) in the Greater Khingan Mountains, China.

    PubMed

    Yin, Y J; Nie, C Y; Liu, W S; Zou, Q; Zhai, J C; Han, H S; Li, H P

    2015-01-01

    Immunoglobulin and cortisol levels are good indicators of well-being and living status in animals. In this study, the concentrations of fecal immunoglobulins A ([IgAF]), G ([IgGF]), and M ([IgMF]), and cortisol ([cortisolF]) were examined by enzyme-linked immunosorbent assay in reindeer of the Greater Khingan Mountains of Inner Mongolia, China. [IgAF] was significantly higher than [IgGF] and [IgMF], and [IgGF] was significantly higher than [IgMF] (P < 0.05). Both [IgAF] and [IgGF] were higher in the Adult group than in Aged or Infant groups, and higher in the Young than Infant group (P < 0.05). The four age group [IgMF]s were not significantly different (P > 0.05). [IgAF], [IgGF], and [IgMF] in each age group were higher in females than in males, with a significant difference in the Young group (P < 0.05). The Infant group had the highest [cortisolF], and the Adult group the lowest; [cortisolF] was significantly higher in the Infant group than in other age groups (P < 0.05). In each age group, [cortisolF] was higher in females than males, and there were significant differences among the Infant, Young, and Aged groups (P < 0.05). A significant negative correlation was observed between [cortisolF] and [IgAF] and [IgGF] (P > 0.05). Overall physical condition was better in the Adult and Young groups than in the Aged and Infant groups as determined by the comprehensive analysis of fecal Ig levels in the four age groups, with the Infant group the worst.

  20. Spatial patterns of (137)Cs inventories and soil erosion from earth-banked terraces in the Yimeng Mountains, China.

    PubMed

    Zhang, Yunqi; Long, Yi; An, Juan; Yu, Xingxiu; Wang, Xiaoli

    2014-10-01

    The Yimeng Mountains is one of China's most susceptible regions to soil erosion. In this region, slopes are composed of granite- or gneiss-derived soils that are commonly cultivated using earth-banked terraces. Based on the (137)Cs measurement for nine reference cores, the present study analysed the spatial patterns of (137)Cs inventory and soil erosion using 105 sampling points in a seven-level earth-banked terrace system. The mean (137)Cs inventory, standard deviation, coefficient of variation, and allowable error for the nine reference cores were 987 Bq m(-2), 71 Bq m(-2), 7%, and 6%, respectively, values that may reflect the heterogeneity of the initial (137)Cs fallout deposit. Within each terrace, the (137)Cs inventory generally increases from the rear edge to the front edge, accompanied by a decrease in the erosion rate. This results from planation by tillage and rainfall runoff during the development of the earth-banked terraces. Across the entire seven-level terrace system, (137)Cs inventories decrease from the highest terrace downwards, but increase in the lower terraces, whereas erosion rate displays the opposite trend. These trends are the result of the combined effects of the earth-bank segmented hillslope, the limited protection of the earth banks, and rainfall runoff in combination with tillage. The high coefficients of variation of (137)Cs inventories for the 21 sampling rows, with a mean value of 44%, demonstrate the combined effects of variations in original microtopography, anthropogenic disturbance, the incohesive soils weathered from underlying granite, and the warm climate. Although earth-banked terraces can reduce soil erosion to some extent, the estimated erosion rates for the study area are still very high.

  1. Evaluation of trace elements contamination in cloud/fog water at an elevated mountain site in Northern China.

    PubMed

    Liu, Xiao-huan; Wai, Ka-ming; Wang, Yan; Zhou, Jie; Li, Peng-hui; Guo, Jia; Xu, Peng-ju; Wang, Wen-xing

    2012-07-01

    Totally 117 cloud/fog water samples were collected at the summit of Mt. Tai (1534m a.s.l.)-the highest mountain in the Northern China Plain. The results were investigated by a combination of techniques including back trajectory model, regional air quality and dust storm models, satellite observations and Principal Component Analysis. Elemental concentrations were determined by Inductively Coupled Plasma Mass Spectrometry, with stringent quality control measures. Higher elemental concentrations were found at Mt. Tai compared with those reported by other overseas studies. The larger proportions and higher concentrations of toxic elements such as Pb and As in cloud/fog water compared with those in rainwater at Mt. Tai suggests higher potential hazards of cloud/fog water as a source of contamination in polluted areas to the ecosystem. Peak concentrations of trace elements were frequently observed during the onset of cloud/fog events when liquid water contents of cloud/fog water were usually low and large amount of pollutants were accumulated in the ambient air. Inverse relationship between elemental concentrations and liquid water contents were only found in the samples with high electrical conductivities and liquid water contents lower than 0.3gm(-3). Affected mainly by the emissions of steel industries and mining activities, air masses transported from south/southwest of Mt. Tai were frequently associated with higher elemental concentrations. The element Mn is attributed to play an important role in the acidity of cloud/fog water. The composition of cloud/fog water influenced by an Asian dust storm event was reported, which was seldom found in the literature. PMID:22503636

  2. Evaluation of trace elements contamination in cloud/fog water at an elevated mountain site in Northern China.

    PubMed

    Liu, Xiao-huan; Wai, Ka-ming; Wang, Yan; Zhou, Jie; Li, Peng-hui; Guo, Jia; Xu, Peng-ju; Wang, Wen-xing

    2012-07-01

    Totally 117 cloud/fog water samples were collected at the summit of Mt. Tai (1534m a.s.l.)-the highest mountain in the Northern China Plain. The results were investigated by a combination of techniques including back trajectory model, regional air quality and dust storm models, satellite observations and Principal Component Analysis. Elemental concentrations were determined by Inductively Coupled Plasma Mass Spectrometry, with stringent quality control measures. Higher elemental concentrations were found at Mt. Tai compared with those reported by other overseas studies. The larger proportions and higher concentrations of toxic elements such as Pb and As in cloud/fog water compared with those in rainwater at Mt. Tai suggests higher potential hazards of cloud/fog water as a source of contamination in polluted areas to the ecosystem. Peak concentrations of trace elements were frequently observed during the onset of cloud/fog events when liquid water contents of cloud/fog water were usually low and large amount of pollutants were accumulated in the ambient air. Inverse relationship between elemental concentrations and liquid water contents were only found in the samples with high electrical conductivities and liquid water contents lower than 0.3gm(-3). Affected mainly by the emissions of steel industries and mining activities, air masses transported from south/southwest of Mt. Tai were frequently associated with higher elemental concentrations. The element Mn is attributed to play an important role in the acidity of cloud/fog water. The composition of cloud/fog water influenced by an Asian dust storm event was reported, which was seldom found in the literature.

  3. Non-invasive determination of the immune physiological state of reindeer (Rangifer tarandus) in the Greater Khingan Mountains, China.

    PubMed

    Yin, Y J; Nie, C Y; Liu, W S; Zou, Q; Zhai, J C; Han, H S; Li, H P

    2015-01-01

    Immunoglobulin and cortisol levels are good indicators of well-being and living status in animals. In this study, the concentrations of fecal immunoglobulins A ([IgAF]), G ([IgGF]), and M ([IgMF]), and cortisol ([cortisolF]) were examined by enzyme-linked immunosorbent assay in reindeer of the Greater Khingan Mountains of Inner Mongolia, China. [IgAF] was significantly higher than [IgGF] and [IgMF], and [IgGF] was significantly higher than [IgMF] (P < 0.05). Both [IgAF] and [IgGF] were higher in the Adult group than in Aged or Infant groups, and higher in the Young than Infant group (P < 0.05). The four age group [IgMF]s were not significantly different (P > 0.05). [IgAF], [IgGF], and [IgMF] in each age group were higher in females than in males, with a significant difference in the Young group (P < 0.05). The Infant group had the highest [cortisolF], and the Adult group the lowest; [cortisolF] was significantly higher in the Infant group than in other age groups (P < 0.05). In each age group, [cortisolF] was higher in females than males, and there were significant differences among the Infant, Young, and Aged groups (P < 0.05). A significant negative correlation was observed between [cortisolF] and [IgAF] and [IgGF] (P > 0.05). Overall physical condition was better in the Adult and Young groups than in the Aged and Infant groups as determined by the comprehensive analysis of fecal Ig levels in the four age groups, with the Infant group the worst. PMID:26125874

  4. Changes in diversity and biomass of bacteria along a shallow snow pit from Kuytun 51 Glacier, Tianshan Mountains, China

    NASA Astrophysics Data System (ADS)

    Xiang, Shu-Rong; Shang, Tian-Cui; Chen, Yong; Jing, Z.-F.; Yao, Tandong

    2009-12-01

    Microorganisms vary in both biomass and diversity composition along glacial depth profiles. However, it is not well known about the major processes controlling the structure diversity shift of microorganisms in a glacier, although, aeolian deposition has been widely accepted as one mechanism regulating the distribution of microorganisms in snow. To better understand the distribution of microorganisms in a glacier, variations in bacterial diversity and biomass along a pit profile from the Kuytun 51 Glacier in the Tianshan Mountains in China were investigated by using 16S rRNA gene library sequencing and flow cytometric analysis with cell sorting markers. Four clone libraries were established from each of the different sampling depths from the snow pit. A total of 311 insert clones were preliminarily screened by HaeIII-based amplified rRNA restriction analysis (ARDRA), and 83 representatives of the unique ARDRA patterns were sequenced. Sequence analysis showed that the bacteria in the snow pit were affiliated with 23 known subphyla within the members of the Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Cyanobacteria phyla. To examine diversity shifts in snow, the diversity structures from the snow pit were also compared with those previously recovered from the different habitats along the Kuytun 51 Glacier surface and from the deep Malan Glacier. The results showed structure shift patterns in bacterial diversity among the surface, deep snow, and deep ice. Sequence analysis displayed a dramatic diversity shift from a mixture of Cyanobacteria and other eubacteria across the glacial surface to other eubacteria without Cyanobacteria in the deep snow. However, the biogeochemical analyses showed great variability in the measured abiotic and biotic components along the pit profile, which reinforced the idea of aeolian deposition being a dominant mechanism controlling the size and diversity of microorganisms in snow. Overall, the findings indicated a

  5. Distribution and assessment of residual mercury from gold mining in Changbai Mountain Range Northeastern China

    NASA Astrophysics Data System (ADS)

    Meng, D.; Wang, N.; Ai, J. C.; Zhang, G.; Liu, X. J.

    2016-08-01

    Gold mining was first initiated in Jiapigou area, Huadian city of Northeastern China about 200 years ago. Before 2006, the mercury amalgamation technique was used in the gold mining process, which led to severe mercury contamination. The aim of this paper is to explore the influences of residual mercury on the environment media after eliminating the amalgamation process to extract gold. The mercury concentrations of the atmosphere and the soil were determined in autumn of 2011 and spring of 2012. The soil environmental quality was assessed by the index of geoaccumulation. The results indicated that the maximum value of gaseous mercury was 25ng•m-3 in autumn and 19.5ng•m-3 in spring; the maximum value of mercury in the soil was 2.06mg•kg-1 in autumn and 2.51mg•kg-1in spring. It can be seen that the peak concentrations of the gaseous mercury happened at the gold mine area and tailings, while the peak mercury concentrations in the soil were located at the places near the mining sites and the residential area in the valley. Furthermore, the regression analysis of the total mercury contents between the atmosphere and the soil showed a significant correlation, which indicated that there was certain circulation of the mercury between the regional atmosphere and soil. In general, after the elimination of the amalgamation technique in gold extraction, the distance to the mercury source, the special conditions of hilly weather and landforms and the mercury exchange flux are the main factors of mercury contamination.

  6. Heavy metal contamination in a typical mining town of a minority and mountain area, South China.

    PubMed

    Zhang, Xin-Ying; Tang, Li-Song; Zhang, Gan; Wu, Hao-Dong

    2009-01-01

    This study was conducted in Dachang, a small mining town in Gaungxi Zhuang Autonomous Region in southern China. A total of 23 farmland soil samples and two atmospheric samples of particulate matter less than 10 microns (PM(10)) were collected in this town. ICP-MS was used to analyze for 20 elements in each of the samples. All of the samples contained some level of heavy metals. The most commonly detected heavy metals detected in the soil samples were: Cd (up to 29.0 mg kg(-1)), As (up to 776 mg kg(-1)), Sb (up to 36.8 mg kg(-1)), Pb (up to 582 mg kg(-1)), Zn (up to 1379 mg kg(-1)) and Cu (up to 156 mg kg(-1)), Mn (up to 1476 mg kg(-1)). The PM(10) content in air samples exceeded the Chinese standard by nearly ten-fold. The most commonly detected heavy metals detected in the PM(10) atmospheric samples were Cd (up to 210 mg kg(-1)), As (up to 15239 mg.kg(-1)), Sb (up to 445 mg kg(-1)), Pb (up to 8053 mg kg(-1)), Zn (up to 13151 mg kg(-1)) and Cu (up to 673 mg kg(-1)), Mn (up to 2826 mg kg(-1)), Mo (up to 120 mg kg(-1)). All of these heavy metals are associated with significant human health effects ranging from reduced intelligent quotients (IQs) in children (cf. Pb) to cancer (e.g., Cd and As). Müller Geo-accumulation Index (Igeo) and enrichment factor (EF) were used to assess the findings. The results to the two assessments showed the same ranking: Cd > As > Sb > Pb > Zn > Cu > Mn, which would imply that the particulate matter in ambient air was the source of the contamination in the soil. The correlation analysis supported this inference. Upon further examination, ore transportation through the town was identified as the most likely source of contamination. Therefore, steps should be taken to improve the management of the ore transportation in order to protect the farmland and the health of the residents.

  7. Building for the Future by Expatiating the Past: High Drama from the Summit of China's Learning Mountain

    ERIC Educational Resources Information Center

    Boshier, Roger; Huang, Yan

    2006-01-01

    As part of a large-scale learning initiative, the Chinese Communist Party has declared Lushan to be a "learning mountain". There have been people learning at Lushan Mountain for 2000 years. In 1959 there was a Central Committee meeting at Lushan, where Mao Zedong purged his widely respected comrade Peng Dehuai for daring to say people were…

  8. Hydrogeochemical and isotopic composition of groundwater in the Horgos River Watershed in the NorthWestern Ili Basin in Sinkiang Province, China

    NASA Astrophysics Data System (ADS)

    Jin, S. H.; Jiang, J. Y.; Rao, J. P.

    2016-08-01

    In this study, hydrogeochemical and stable environmental isotopic (oxygen-18 and deuterium) data of groundwater in the Horgos River watershed in the north-western Ili Basin were examined to determine the groundwater chemical characteristics, as well as the origins of the groundwater and surface water. The quaternary aquifer's structure and spatial distribution is complex. Hydrogeochemical data shows that the groundwater is alkaline due to the presence of bicarbonate as the dominant anion. In the north, the dominant groundwater cation was Ca2+ while Mg2+ ions were highest in the south. In addition, water types varied from HCO3-SO4-Ca and HCO3-SO4-Ca-Mg to HCO3-SO4-Mg-Ca and SO4-HCO3-Mg-Ca. Overall, the groundwater in this study showed high total hardness. The dissolving and evaporation inspissation were considered the main controlling factors. Isotopic data (oxygen-18 and deuterium) indicated that the Horgos River was the main recharge source for the groundwater, which rapidly infiltrated across sandstone macropores. Furthermore, surface water and shallow groundwater were significantly affected by evaporation.

  9. Analysis of the genetic diversity of the nematode parasite Baylisascaris schroederi from wild giant pandas in different mountain ranges in China

    PubMed Central

    2013-01-01

    Background Baylisascaris schroederi is one of the most common nematodes of the giant panda, and can cause severe baylisascarosis in both wild and captive giant pandas. Previous studies of the giant pandas indicated that this population is genetically distinct, implying the presence of a new subspecies. Based on the co-evolution between the parasite and the host, the aim of this study was to investigate the genetic differentiation in the B. schroederi population collected from giant pandas inhabiting different mountain ranges, and further to identify whether the evolution of this parasite correlates with the evolution of giant pandas. Methods In this study, 48 B. schroederi were collected from 28 wild giant pandas inhabiting the Qinling, Minshan and Qionglai mountain ranges in China. The complete sequence of the mitochondrial cytochrome b (mtCytb) gene was amplified by PCR, and the corresponding population genetic diversity of the three mountain populations was determined. In addition, we discussed the evolutionary relationship between B. schroederi and its host giant panda. Results For the DNA dataset, insignificant Fst values and a significant, high level of gene flow were detected among the three mountain populations of B. schroederi, and high genetic variation within populations and a low genetic distance were observed. Both phylogenetic analyses and network mapping of the 16 haplotypes revealed a dispersed pattern and an absence of branches strictly corresponding to the three mountain range sampling sites. Neutrality tests and mismatch analysis indicated that B. schroederi experienced a population expansion in the past. Conclusions Taken together, the dispersed haplotype map, extremely high gene flow among the three populations of B. schroederi, low genetic structure and rapid evolutionary rate suggest that the B. schroederi populations did not follow a pattern of isolation by distance, indicating the existence of physical connections before these populations

  10. Reservoir microfacies and their logging response of gas hydrate in the Qilian Mountain permafrost in Northwest China

    NASA Astrophysics Data System (ADS)

    Liu, H.; Lu, Z.; Zhang, Y.; Sun, Z.

    2012-12-01

    The Qilian Mountain permafrost is located in the north margin of the Qinghai-Tibet Plateau in northwest China. The permafrost area is about 10×104 Km2, and dominated by mountain permafrost. The mean annual ground temperature is 1.5 to 2.4 centigrade and the thickness of permafrost is generally 50 to 139 m. The gas hydrate was sampled successfully in the 133-396m interval from holes DK-1, DK-2 and DK-3 and tested by microRaman spectroscopy in the hydrate laboratory of the Qingdao Institute of Marine Geology during June to September in 2009. The exploratory drilling indicated that gas hydrate and its abnormal occurrence are mainly developed 130-400 m beneath permafrost. The strata belong to the Jiangcang Formation of middle Jurassic. Based on lithology, sedimentary structure and sequence and other facies markers, reservoir microfacies of gas hydrate are identified as underwater distributary channel and interdistributary bay in delta front of delta and deep lake mudstone facies in lacustrine. The underwater distributary channel in delta front of delta is dominated by fine sandstone. It has little mudstone. The grain size generally becomes finer, and scour-filling structure, parallel bedding, cross bedding and wavy bedding develop successively from bottom to top in one phase of channel. In vertical multi-period distributary channels superimpose, forming thick sandstone, and sometimes a thin mudstone develop between two channels. The interdistributaty bay is characterized by mudstone with little siltstone and fine sandstone. The lithology column shows mudstone interbedded with thin sandstone. Horizon bedding and lenticular bedding are the main structure. The gas hydrate usually presents visible white (smoky gray when mixing with mud) ice-like lamina in fissures or invisible micro disseminated occurrence in pores of sandstone. Honeycomb pores formed by the decomposition of gas hydrate are usually found in sandstone. The deep lake is dominated by thick dark grey mudstone

  11. Correlation and periodicity analysis between herbage yields and climatic factors in the Tianshan Mountain,China in 22 year periods.

    NASA Astrophysics Data System (ADS)

    Jianlong, L.

    2009-04-01

    To analyze the relationship between herbage yields and climatic factors, 22 years of herbage yields and climate data were collected on the northern slope of the Tianshan Mountains region of western China. Using multiple regression analysis, maximum entropy spectrum analysis and cross spectrum analysis, it was clarified that fluctuation of climatic factors affected herbage yields and their periodical variation. The herbage yields were correlated significantly to the four climate factors including annual precipitation, annual means of relative humidity, absolute humidity and percentage of sunshine, but unrelated to the trend variable (the former year yield has little effects on the later) and other climatic factors. These clarified that long term variation of grassland productivity responded directly to changes of some climate factors in typical zone of arid continental climate. The results in co-spectrum and quadrature spectrum analysis revealed that the herbage yields had 4-year period similar to some moisture factors, and with 1/4 period delay. These findings demonstrated further that the fluctuation of some climatic elements (precipitation particularly) was the crucial factor affecting the variations of herbage yields of natural grassland in arid and semiarid ecosystem. The periodical change of vegetation and correlation with climate provide us a way to predict the herbage production according to the climate change, and it was important for the herdsmen to arrange predictively their animal production including rectifying their livestock population in natural grazing land and storing up the supply of forage timely for livestock use in cold season. Our finding in periodical variation of climatic element and plant yield further demonstrated the crucial driver of some climate factors on formation of herbage yields. The same or similar quasi-4-year period in climatic element and vegetation was due to that periodical variation of climatic element (especially

  12. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    PubMed

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments. PMID:26841776

  13. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    PubMed

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

  14. Glacial erosion, deep exhumation and the development of high topography along the Kongur detachment, Pamir Mountains, Western China

    NASA Astrophysics Data System (ADS)

    Schoenbohm, L.; Chen, J.; Sobel, E.; Thiede, R.; Strecker, M.

    2006-12-01

    In the Pamir mountains of western China, in the footwall of the Kongur detachment, the correlation of the high peaks Kongur Shan (7719 m) and Muztagh Ata (7546m), large glaciers, exhumation of mid-crustal rocks and rapid cooling suggests the development of a system in which (1) erosion effectively removes material, driving advection of increasingly hotter, weaker rock, forming the gneiss domes which underlie the peaks, and (2) glaciers drive relief production and peak uplift, enhancing orographic precipitation, thus forming larger, more erosive glaciers. We suggest a scenario in which initial structural unroofing of the footwall, increased peak height and the resulting orographic focusing of precipitation may have led to increased glacial erosion. Glaciation would have been most significant in the south where the peaks were highest. The additional component of exhumation in the southern regions then drove greater structural exhumation, maintaining high topography and establishing a climate-moderated feedback loop. In order to understand the importance of glaciation in this scenario, we look to understanding temporal and spatial erosion and deposition in the valley. Three glacial sequences (moraine deposition, terrace formation, erosion) are recorded in the hanging wall valley, successively decreasing in extent. The extent of glaciation varies significantly from the north, where moraines are limited to the mouths of tributary valleys, to the south, where moraines completely filled the main valley. This variation is the result of the southward increasing range height and landscape area above the ELA. With moraine volume, measured from field mapping and ASTER imagery as a proxy for relative glacial erosion, we confirm that glacial erosion increases in concert with peak elevations and degree of exhumation. New cosmogenic 10Be data for three locations on the dominant terrace level will constrain the age of the successive moraine deposits and allow a comparison of

  15. Using Psinsar to Detect Thermokarst-Induced Surface Subsidence in Eboling Mountain on the Qinghai-Tibet Plateau of China

    NASA Astrophysics Data System (ADS)

    Chen, J.; Liu, L.; Lin, H.; Zhang, T.; Cao, B.

    2015-12-01

    Thermokarst, a process that characterizes landforms caused by thawing of ice-rich permafrost, is a key indicator of permafrost degradation. Surface dynamics of thermokarst processes on Qinghai-Tibet Plateau (QTP) of China, is still poorly quantified or understood. It is also challenging to detect and measure surface subsidence due to loss of subsurface ice over a large area. In this study, the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique is used to retrieve surface subsidence located at Eboling Mountain, near the northern edge of the QTP. Persistent Scatterer (PS) refers to stable natural or man-made object with good coherence in temporal domain. Based on the assumption that the residual phase of nearby PS is smaller than , we can retrieve the unwrapped phase associated with the sparsely irregular data. Using 17 L-band ALOS-1 PALSAR images taken from 2006 to 2011, we find linear deformation trends of up to 50 millimeters per year and seasonal subsidence of up to 80 millimeters over the area where thermokarst gullies are present (location: 38.01° N ,100.90° E , Figure 1), associated with thermokarst development and seasonal thawing of active layer, respectively. Furthermore, to the northwest and northeast of the Eboling thermokarst area, there are several small areas with large subsidence trends, which may also be related to thermokarst processes. This study demonstrates that the PSInSAR technique has the ability to map and quantify thermokarst-induced subsidence spanning multiple years using ALOS-1 PALSAR images. Yet as the thermokarst processes are much more complex in nature than a simple subsidence trend, more efforts are required (1) to validate the PSInSAR results with in situ measurements, (2) to better separate thermokarst-induced subsidence from seasonal ground elevation changes by including winter PSInSAR data and accounting for frost heave processes, and (3) to quantify potential aliasing problem due to the sparse

  16. Empirical relationship between leaf wax n-alkane δD and altitude in the Wuyi, Shennongjia and Tianshan Mountains, China: Implications for paleoaltimetry

    NASA Astrophysics Data System (ADS)

    Luo, Pan; Peng, Ping'an; Gleixner, Gerd; Zheng, Zhuo; Pang, Zhonghe; Ding, Zhongli

    2011-01-01

    Estimating past elevation not only provides evidence for vertical movements of the Earth's lithosphere, but also increases our understanding of interactions between tectonics, relief and climate in geological history. Development of biomarker hydrogen isotope-based paleoaltimetry techniques that can be applied to a wide range of sample types is therefore of continuing importance. Here we present leaf wax-derived n-alkane δD (δDwax) values along three soil altitudinal transects, at different latitudes, in the Wuyi, Shennongjia and Tianshan Mountains in China, to investigate δDwax gradients and the apparent fractionation between leaf wax and precipitation (εwax-p). We find that soil δDwax track altitudinal variations of precipitation δD along the three transects that span variable environment conditions and vertical vegetation spectra. An empirical δDwax-altitude relation is therefore established in which the average δDwax lapse rate of - 2.27 ± 0.38‰/100 m is suitable for predicting relative paleoelevation change (relative uplift). The application of this empirical gradient is restricted to phases in the mountain uplift stage when the atmospheric circulation had not distinctly changed and to when the climate was not arid. An empirical δDwax-latitude-altitude formula is also calculated: δDwax = 3.483LAT - 0.0227ALT - 261.5, which gives the preliminary spatial distribution pattern of δDwax in modern China. Mean value of εwax-p in the extreme humid Wuyi Mountains is quite negative (- 154‰), compared to the humid Shennongjia (- 129‰) and the arid (but with abundant summer precipitation) Tianshan Mountains (- 130‰), which suggests aridity or water availability in the growing season is the primary factor controlling soil/sediment εwax-p. Along the Tianshan transects, values of εwax-p are speculated to be constant with altitude; while along the Wuyi and Shennongjia transects, εwax-p are also constant at the low-mid altitudes, but become slightly

  17. Knowledge of, attitudes towards, and practice relating to schistosomiasis in two subtypes of a mountainous region of the People’s Republic of China

    PubMed Central

    2014-01-01

    Background Schistosomiasis japonica is still endemic in the People’s Republic of China (P.R. China) in five provinces of lake and marshland regions and in two provinces of mountainous regions. Studies elucidated that individual and community perception, attitudes towards schistosomiasis, and hygiene behaviors were crucial factors for preventing schistosomiasis. This study sought to assess the knowledge of, attitudes towards, and practices (KAP) relating to schistosomiasis in two subtypes of a mountainous region in Eryuan County, Yunnan Province, P.R. China. The study’s aim is to make suggestions for establishing more specific and effective control measures for disease transmission and interruption in two subtypes of a mountainous region with low-level infection rates. Methods A cross-sectional study of 3,000 inhabitants was carried out in the Yongle (plateau basin) and Xinzhuang (plateau canyon) communities of Eryuan County, Yunnan Province in November and December 2011. Stratified cluster random sampling was undertaken using a uniform set of quantitative questionnaires administered by trained assistants. This was further supported with qualitative data from in-depth interviews (IDIs) conducted with ten farmers and ten students. All participants were examined for schistosomiasis using both a serological test (indirect hemagglutination assay [IHA]) and a stool examination (Kato-Katz). Results The total schistosomiasis knowledge rate in Yongle (83.4%) was significantly lower than that in Xinzhuang (95.5%). In both communities, among the respondents aged 15 years or below, more than one third didn’t know the name, endemic areas, and animal reservoirs of schistosomiasis. The majority of respondents in Eryuan acquired their schistosomiasis knowledge from doctors, followed by handouts and hearing from others. The infection rate was once the highest in Yongle, but is now the highest in Xinzhuang, where there are more risk factors for schistosomiasis, such as

  18. Zircon U-Pb geochronology of the basement rocks and dioritic intrusion associated with the Fushan skarn iron deposit, southern Taihang Mountains, China

    NASA Astrophysics Data System (ADS)

    Shen, Jun-Feng; Li, Sheng-Rong; Santosh, M.; Dong, Guo-Chen; Wang, Yan-Juan; Liu, Hai-Ming; Peng, Zi-Dong; Zhang, Zhao-Yu

    2015-12-01

    The Fushan iron ores, located in the southern part of the Taihang Mountains (TM) within the Trans-North China Orogen, is among the medium-sized skarn iron deposits in China. In this paper we report U-Pb age data on zircon grains from the magmatic intrusion related with the skarn formation and from the Neoarchean metamorphic basement in the area. The results show that the dioritic intrusion which generated the skarn mineralization was emplaced at 128.8 ± 1.9 Ma. Zircon grains from the basement rocks and xenoliths, as well as inherited zircon in the dioritic intrusion show Neoarchean to Paleoproterozoic ages, corresponding to similar ages reported from elsewhere in the North China Craton. Our results and those from previous studies suggest that the continental lower crust was the major source of Mesozoic magmatism and associated ore mineralization. The Mesozoic magmatism and metallogeny in the Fushan region correlate with the peak of lithospheric destruction of the North China Craton.

  19. Molecular systematics of Angelica and allied genera (Apiaceae) from the Hengduan Mountains of China based on nrDNA ITS sequences: phylogenetic affinities and biogeographic implications.

    PubMed

    Feng, Tu; Downie, Stephen R; Yu, Yan; Zhang, Xuemei; Chen, Weiwei; He, Xingjin; Liu, Shuang

    2009-07-01

    Maximum parsimony, maximum likelihood, and Bayesian analyses of nuclear ribosomal DNA internal transcribed spacer sequences were used to infer the phylogenetic affinities and historical biogeography of Angelica and its allies (Apiaceae tribe Selineae), with emphasis on those species of Angelica and Peucedanum endemic to the Hengduan Mountains of south-central China. Results of these analyses corroborate a monophyletic Angelica (Angelica sensu stricto) upon the inclusion of Coelopleurum, Czernaevia, and one of two examined species of Ostericum, but with the exclusion of several species previously attributable to Angelica. Angelica oncosepala and A. likiangensis arise within the genus Heracleum in tribe Tordylieae; the former is recognized under its original name, Heracleum oncosepalum. Angelica sinensis, A. tianmuensis and A. paeoniifolia arise within the Sinodielsia clade of previous circumscription, closely related to Levisticum officinale. Angelica anomala is a sister group to Ostericum grosseserratum in the previously delimited Acronema clade. Angelica apaensis and A. decursiva, taxa whose phylogenetic affinities have previously been controversial, are confirmed within Angelica. Northeast Asia (including Japan, northeast China, Korea and adjacent areas of Russia), Western Europe, and North America are inferred to be ancestral areas of Angelica based on optimal solutions of a dispersal-vicariance analysis, with the Hengduan Mountains likely providing a refugium for Angelica during the latter part of the Tertiary.

  20. Contingency table analysis of pebble lithology and roundness: A case study of Huangshui River, China and comparison to rivers in the Rocky Mountains, USA

    USGS Publications Warehouse

    Miao, X.; Lindsey, D.A.; Lai, Z.; Liu, Xiuying

    2010-01-01

    Contingency table analysis of pebble lithology and roundness is an effective way to identify the source terrane of a drainage basin and to distinguish changes in basin size, piracy, tectonism, and other events. First, the analysis to terrace gravel deposited by the Huangshui River, northeastern Tibet Plateau, China, shows statistically contrasting pebble populations for the oldest terrace (T7, Dadongling, 1.2. Ma) and the youngest terraces (T0-T3, ?. 0.15. Ma). Two fluvial processes are considered to explain the contrast in correlation between lithology and roundness in T7 gravel versus T0-T3 gravel: 1) reworking of T7 gravel into T0-T3 gravel and 2) growth in the size of the river basin between T7 and T0-T3 times. We favor growth in basin size as the dominant process, from comparison of pebble counts and contingency tables. Second, comparison of results from Huangshui River of China to three piedmont streams of the Rocky Mountains, USA highlights major differences in source terrane and history. Like Rocky Mountain piedmont gravel from Colorado examples, the Huangshui gravels show a preference (observed versus expected frequency) for rounded granite. But unlike Rocky Mountain gravel, Huangshui gravel shows a preference for angular quartzite and for rounded sandstone. In conclusion, contrasting behavior of lithologies during transport, not always apparent in raw pebble counts, is readily analyzed using contingency tables to identify the provenance of individual lithologies, including recycled clasts. Results of the analysis may help unravel river history, including changes in basin size and lithology. ?? 2009.

  1. Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating.

    PubMed

    Bao, K; Xia, W; Lu, X; Wang, G

    2010-09-01

    Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using (210)Pb and (137)Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported (210)Pb and (137)Cs decreased with the depth in both of the two sample cores. The (210)Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the (137)Cs time marker. Recent atmospheric (210)Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m(-2)y(-1), which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m(-2)y(-1) with a range of Pb concentration of 14-262 microg g(-1). The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.

  2. [Estimation of carbonaceous gases emission from forest fires in Xiao Xing'an Mountains of Northeast China in 1953-2011].

    PubMed

    Hu, Hai-Qing; Luo, Bi-Zhen; Wei, Shu-Jing; Sun, Long; Wei, Shu-Wei; Wen, Zheng-Min

    2013-11-01

    Based on the forest resources investigation data and the forest fire inventory in 1953-2011, in combining with our field research in burned areas and our laboratory experiments, this paper estimated the carbonaceous gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and nonmethane hydrocarbons (NMHC) emission from the forest fires in Xiao Xing' an Mountains of Heilongjiang Province, Northeast China in 1953-2011. The total carbon emission from the forest fires in the Xiao Xing'an Mountains in 1953-2011 was 1.12 x 10(7) t, and the annual emission was averagely 1.90 x10(5) t, accounting for 1.7% of the annual average total carbon emission from the forest fires in China. The emission of CO2, CO, CH4, and NMHC was 3.39 x 10(7), 1.94 x 10(5), 1.09 x 10(5), and 7.46 x 10(4) t, respectively, and the corresponding annual average emission was 5.74 x 10(5), 3.29 x 10(4), 1.85 x 10(3), and 1.27 x 10(3) t, accounting for 1.4%, 1.2%, 1.7%, and 1.1% of the annual carbonaceous gases emitted from the forest fires in China, respectively. The combustion efficiency and the carbon emission per unit burned area of different forest types decreased in order of coniferous forest > broad-leaved forest > coniferous broadleaved mixed forest. Some rational forest fire management measures were put forward.

  3. Current and Potential Tree Locations in Tree Line Ecotone of Changbai Mountains, Northeast China: The Controlling Effects of Topography

    PubMed Central

    Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

    2014-01-01

    Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountains. To test the hypothesis, we used IKONOS images and WorldView-1 image to identify the tree locations and developed a logistic regression model using topographical variables to identify the dominant controls of the tree locations. The results showed that aspect, wetness, and slope were dominant controls for tree locations on western side of the mountains, whereas altitude, SPI, and aspect were the dominant factors on northern side. The upmost altitude a tree can currently reach was 2140 m asl on the northern side and 2060 m asl on western side. The model predicted results showed that habitats above the current tree line on the both sides were available for trees. Tree recruitments under the current tree line may take advantage of the available habitats at higher elevations based on the current tree location. Our research confirmed the controlling effects of topography on the tree locations in the tree line ecotone of Changbai Mountains and suggested that it was essential to assess the tree response to topography in the research of tree line ecotone. PMID:25170918

  4. Association of urinary monomethylated arsenic concentration and risk of hypertension: a cross-sectional study from arsenic contaminated areas in northwestern China

    PubMed Central

    2013-01-01

    Background Although some studies mainly from Taiwan, Bangladesh and the United States, have suggested a consistent dose–response increase in the prevalence of hypertension with increasing arsenic exposure, the association between chronic environmental arsenic exposure and the risk of hypertension is still inconclusive. Most of the studies discussed the association from the point of view of arsenic concentration in drinking water or cumulative arsenic exposure (CAE), few involved arsenic speciation into the discussion. In this cross-sectional study, we evaluated the potential association between environmental arsenic exposure through drinking water and the prevalence of hypertension by analyzing not only CAE but also urinary arsenic speciation, and provided data on arsenic exposure and hypertension from mainland of China. Methods A cross-sectional study was conducted in one of the arsenic contaminated areas in the northwest of China. Among a total of 1005 residents who voluntarily participated in the study, 604 of eligible subjects were confirmed and interviewed door to door. Standing height, body weight, and blood pressure were measured. First void urine was collected and measured for the concentration of urinary arsenic speciation. CAE was calculated in a subpopulation of 360 subjects with detailed water consumption history. The association between urinary arsenic speciation, CAE and the risk of hypertension were analyzed by multiple logistic regressions. Results We found that the levels of urinary arsenic species of inorganic arsenic (iAs), monomethylated arsenic (MMA), dimethylated arsenic (DMA) and total arsenic (tAs) were significantly correlated with systolic or pulse blood pressure. A positive relationship was found between the highest tertile of CAE and hypertension in a dose-dependent manner. Subjects with higher concentration of urinary MMA or lower percentage of DMA tended to be liable to suffer from hypertension. A significant increasing trend of the

  5. Late Quaternary tectonic activity and crustal shortening rate of the Bogda mountain area, eastern Tian Shan, China

    NASA Astrophysics Data System (ADS)

    Wu, Chuanyong; Wu, Guodong; Shen, Jun; Dai, Xunye; Chen, Jianbo; Song, Heping

    2016-04-01

    The Bogda mountain range is the highest range among the northern Tian Shan mountains. Based on geologic and geomorphologic field surveys, trench excavation and optically stimulated luminescence (OSL) dating, we targeted the active Fukang fault along the Bogda mountain range and identified the late Quaternary deformation characteristics of this area. We found that the Fukang fault dislocated different geomorphic surfaces of the northern Bogda piedmont. The vertical fault displacement corresponds to the topographic relief of the Bogda over long time scales. Since the late Quaternary, the crustal shortening rate was estimated to be 0.90 ± 0.20 mm/yr, which is less than that of the western segment of the northern Tian Shan. We interpret the Bogda fold and thrust belt to be a thick-skinned structure, since a high angle thrust fault bounds the Bogda mountain range and the foreland basin. The deformation characteristics of this region have been dominated by vertical uplift, and the component of propagation toward the basin has been very limited. This tectonic deformation is evidenced as vertical growth. Although the deformation rate is small, the uplift amplitude is very significant in this region.

  6. Insights from heavy minerals and zircon U-Pb ages into the middle Miocene-Pliocene provenance evolution of the Yinggehai Basin, northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Jiang, Tao; Cao, Licheng; Xie, Xinong; Wang, Zhenfeng; Li, Xushen; Zhang, Yingzhao; Zhang, Daojun; Sun, Hui

    2015-08-01

    The well-preserved Cenozoic sedimentary record in the Yinggehai Basin, South China Sea, is suitable to explore the tectonic and climatic evolution of SE Asia. Red River, a large-scale fluvial system in this region, was previously regarded as the major sediment source for the basin. Here we combine heavy mineral analysis and detrital zircon U-Pb dating to shed new light on the middle Miocene-Pliocene provenance evolution at a basin scale. The results clearly reveal potential source areas additional to the Red River. Sediments have been delivered to the proximal areas from Hainan Island, as indicated by the high zircon content and the Yanshanian U-Pb ages in the southern segment of the Yingdong Slope. A provenance from Central Vietnam is explicitly discerned in the upper Miocene of the Central Depression, where sediments are characterized by few metamorphic heavy minerals and the U-Pb age pattern peaking at around 250 Ma and 440 Ma. Coeval large-scale relative sea-level fall and rapid exhumation along the Vietnamese margin together may have facilitated this long-distance sediment transport. Provenance of sediments from the Red River seems to change over time. Song Lo River, on the north side of the main stream, probably flowed from the NE and carried Neoproterozoic-early Paleozoic zircons to the Yinggehai Basin during the middle Miocene. Since the late Miocene, rocks along the Red River Fault Zone have become the dominant source. Subsequently, widespread metamorphic minerals in the Central Depression of the Yinggehai Basin, combined with the strong river incision and high offshore sedimentation rates, indicate an increased sediment supply from the Red River in the Pliocene.

  7. Seasonal and interannual variation of radiation and energy fluxes over a rain-fed cropland in the semi-arid area of Loess Plateau, northwestern China

    NASA Astrophysics Data System (ADS)

    Chen, Xing; Yu, Ye; Chen, Jinbei; Zhang, Tangtang; Li, Zhenchao

    2016-07-01

    Understanding the land-atmosphere interactions over the semi-arid area of Loess Plateau is important due to its special climate and unique underlying surface. In this study, two years' micrometeorological and energy flux observations from the Pingliang Land Surface Process & Severe Weather Research Station, CAS were used to investigate the seasonal and interannual variations of radiation budget and energy fluxes over a rain-fed cropland in the semi-arid area of Loess Plateau, with an emphasis on the influence of rain, soil moisture and agricultural production activities (such as crop type and harvest time) on the energy partitioning as well as the surface energy balance. The results revealed large annual variations in the seasonal distribution of precipitation, which gave rise to significant seasonal and interannual variations in soil moisture. Soil moisture was the main factor affecting radiation budget and energy partitioning. There was a negatively linear relationship between the albedo and the soil moisture. The main consumer of available energy varied among months and years with an apparent water stress threshold value of ca. 0.12 m3 m- 3, and the evapotranspiration was suppressed especially during the growing season. On an annual scale, the largest consumer of midday net radiation was sensible heat flux in 2010-2011, while it was latent heat flux in 2011-2012, which accounted for about 35% and 40% of the net radiation, respectively. The agricultural activity altered the sensitivity and variability of albedo to soil moisture, as well as energy partitioning patterns. The surface energy budget closures during Dec. 2010-Nov. 2011 and Dec. 2011-Nov. 2012 were 77.6% and 73.3%, respectively, after considering the soil heat storage. The closure was comparable to other sites in ChinaFLUX (49% to 81% of 8 sites). The patterns of energy partitioning and the water stress threshold found in the semi-arid cropland could be used to evaluate and improve land surface models.

  8. Obesity inversely correlates with prostate-specific antigen levels in a population with normal screening results of prostate cancer in northwestern China.

    PubMed

    Zhang, J; Ma, M; Nan, X; Sheng, B

    2016-07-11

    Serum prostate-specific antigen (PSA) is a diagnostic biomarker of prostate cancer and is possibly associated with obesity. This study aimed to explore the relationships between obesity indicators [body mass index (BMI) and waist circumference (WC)] with PSA in Chinese men. A cross-sectional study of men aged 30-85 years undergoing prostate cancer screening was conducted from August 2008 to July 2013 in Xi'an, China. Data were obtained from clinical reports, condition was recorded based on self-report including demographics, weight, height, and WC (>90 cm=obese). Fasting blood glucose (FBG) and prostate volume (PV) were assessed clinically. Patients were grouped by BMI (normal=22.9, overweight=23-27.4, obese≥27.5 kg/m2). PSA parameters of density (PSAD), PSA serum level, and PSA increasing rate per year (PSAR) were calculated per BMI and age groups (30-40, 41-59, 60-85 years). Obesity indicators (BMI and WC) and PSA parameter relationships were modeled by age-stratified linear regression. Of 35,632 Chinese men surveyed, 13,084 were analyzed, including 13.44% obese, 57.44% overweight, and 29.12% normal weight, according to BMI; 25.84% were centrally (abdominally) obese according to WC. BMI and WC were negatively associated with all PSA parameters, except PSAD and PSAR [P<0.05, BMI: β=-0.081 (95%CI=-0.055 to -0.036), WC: β=-0.101 (-0.021 to -0.015)], and independent of FBG and PV (P<0.05) in an age-adjusted model. In conclusion, obesity was associated with lower PSA in Chinese men. Therefore, an individual's BMI and WC should be considered when PSA is used to screen for prostate cancer. PMID:27409334

  9. Performance of a pilot demonstration-scale hybrid constructed wetland system for on-site treatment of polluted urban river water in Northwestern China.

    PubMed

    Zheng, Yucong; Wang, Xiaochang C; Dzakpasu, Mawuli; Ge, Yuan; Zhao, Yaqian; Xiong, Jiaqing

    2016-01-01

    Hybrid constructed wetland (HCW) systems have been used to treat various wastewaters across the world. However, large-scale applications of HCWs are scarce, particularly for on-site improvement of the water quality of highly polluted urban rivers in semi-arid regions. In this study, a large pilot-scale HCW system was constructed to improve the water quality of the Zaohe River in Xi'an, China. With a total area of about 8000 m(2), the pilot HCW system, composed of different configurations of surface and subsurface flow wetlands, was operated for 2 years at an average inflow volume rate of 362 m(3)/day. Local Phragmites australis and Typha orientalis from the riverbank were planted in the HCW system. Findings indicate a higher treatment efficiency for organics and suspended solids than nutrients. The inflow concentrations of 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (TN), NH3-N, and total phosphorus (TP) were 125.6, 350.9, 334.2, 38.5, 27.2, and 3.9 mg/L, respectively. Average removal efficiencies of 94.4, 74.5, 92.0, 56.3, 57.5, and 69.2%, respectively, were recorded. However, the pollutant removal rates were highly seasonal especially for nitrogen. Higher removals were recorded for all pollutants in the autumn while significantly lower removals were recorded in the winter. Plant uptake and assimilation accounted for circa 19-29 and 16-23% of the TN and TP removal, respectively. Moreover, P. australis demonstrated a higher nutrient uptake ability and competitive potential. Overall, the high efficiency of the pilot HCW for improving the water quality of such a highly polluted urban river provided practical evidence of the applicability of the HCW technology for protecting urban water environments.

  10. Performance of a pilot demonstration-scale hybrid constructed wetland system for on-site treatment of polluted urban river water in Northwestern China.

    PubMed

    Zheng, Yucong; Wang, Xiaochang C; Dzakpasu, Mawuli; Ge, Yuan; Zhao, Yaqian; Xiong, Jiaqing

    2016-01-01

    Hybrid constructed wetland (HCW) systems have been used to treat various wastewaters across the world. However, large-scale applications of HCWs are scarce, particularly for on-site improvement of the water quality of highly polluted urban rivers in semi-arid regions. In this study, a large pilot-scale HCW system was constructed to improve the water quality of the Zaohe River in Xi'an, China. With a total area of about 8000 m(2), the pilot HCW system, composed of different configurations of surface and subsurface flow wetlands, was operated for 2 years at an average inflow volume rate of 362 m(3)/day. Local Phragmites australis and Typha orientalis from the riverbank were planted in the HCW system. Findings indicate a higher treatment efficiency for organics and suspended solids than nutrients. The inflow concentrations of 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (TN), NH3-N, and total phosphorus (TP) were 125.6, 350.9, 334.2, 38.5, 27.2, and 3.9 mg/L, respectively. Average removal efficiencies of 94.4, 74.5, 92.0, 56.3, 57.5, and 69.2%, respectively, were recorded. However, the pollutant removal rates were highly seasonal especially for nitrogen. Higher removals were recorded for all pollutants in the autumn while significantly lower removals were recorded in the winter. Plant uptake and assimilation accounted for circa 19-29 and 16-23% of the TN and TP removal, respectively. Moreover, P. australis demonstrated a higher nutrient uptake ability and competitive potential. Overall, the high efficiency of the pilot HCW for improving the water quality of such a highly polluted urban river provided practical evidence of the applicability of the HCW technology for protecting urban water environments. PMID:26310702

  11. Obesity inversely correlates with prostate-specific antigen levels in a population with normal screening results of prostate cancer in northwestern China

    PubMed Central

    Zhang, J.; Ma, M.; Nan, X.; Sheng, B.

    2016-01-01

    Serum prostate-specific antigen (PSA) is a diagnostic biomarker of prostate cancer and is possibly associated with obesity. This study aimed to explore the relationships between obesity indicators [body mass index (BMI) and waist circumference (WC)] with PSA in Chinese men. A cross-sectional study of men aged 30-85 years undergoing prostate cancer screening was conducted from August 2008 to July 2013 in Xi'an, China. Data were obtained from clinical reports, condition was recorded based on self-report including demographics, weight, height, and WC (>90 cm=obese). Fasting blood glucose (FBG) and prostate volume (PV) were assessed clinically. Patients were grouped by BMI (normal=22.9, overweight=23-27.4, obese≥27.5 kg/m2). PSA parameters of density (PSAD), PSA serum level, and PSA increasing rate per year (PSAR) were calculated per BMI and age groups (30-40, 41-59, 60-85 years). Obesity indicators (BMI and WC) and PSA parameter relationships were modeled by age-stratified linear regression. Of 35,632 Chinese men surveyed, 13,084 were analyzed, including 13.44% obese, 57.44% overweight, and 29.12% normal weight, according to BMI; 25.84% were centrally (abdominally) obese according to WC. BMI and WC were negatively associated with all PSA parameters, except PSAD and PSAR [P<0.05, BMI: β=-0.081 (95%CI=-0.055 to -0.036), WC: β=-0.101 (-0.021 to -0.015)], and independent of FBG and PV (P<0.05) in an age-adjusted model. In conclusion, obesity was associated with lower PSA in Chinese men. Therefore, an individual's BMI and WC should be considered when PSA is used to screen for prostate cancer. PMID:27409334

  12. Seed dormancy, seedling establishment and dynamics of the soil seed bank of Stipa bungeana (Poaceae) on the Loess Plateau of northwestern China.

    PubMed

    Hu, Xiao Wen; Wu, Yan Pei; Ding, Xing Yu; Zhang, Rui; Wang, Yan Rong; Baskin, Jerry M; Baskin, Carol C

    2014-01-01

    Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls), chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling emergence was monitored weekly for 8 weeks. Furthermore, seeds were buried at different soil depths, and then retrieved every 1 or 2 months to determine seed dormancy and seed viability in the laboratory. Fresh seeds (caryopses enclosed by palea and lemma) had non-deep physiological dormancy. Removal of palea and lemma, chemical scarification, dry storage (afterripening), gibberellin (GA3) and potassium nitrate (KNO3) significantly improved germination. Dormancy was completely released by removal of the hulls, but seeds on which hulls were put back to their original position germinated to only 46%. Pretreatment of seeds with a 30% NaOH solution for 60 min increased germination from 25% to 82%. Speed of seedling emergence from fresh seeds was significantly lower than that of seeds stored for 1 year. However, final percentage of seedling emergence did not differ significantly for seeds sown at depths of 0 and 1 cm. Most fresh seeds of S. bungeana buried in the field in early July either had germinated or lost viability by September. All seeds buried at a depth of 5 cm had lost viability after 5 months, whereas 12% and 4% seeds of those sown on the soil surface were viable after 5 and 12 months, respectively.

  13. Tertiary paleomagnetic data from northwestern Yunnan, China: further evidence for large clockwise rotation of the Indochina block and its tectonic implications

    NASA Astrophysics Data System (ADS)

    Sato, Ken; Liu, Yuyan; Zhu, Zhicheng; Yang, Zhenyu; Otofuji, Yo-ichiro

    2001-02-01

    Eocene red sandstones were collected at 15 sites for paleomagnetic study from two areas (Lanping and Yunlong) of the western part of Yunnan province, China, in the northern part of Indochina. The high-temperature magnetization component with an unblocking temperature of around 680°C is isolated after stepwise thermal demagnetization. Characteristic directions from nine accepted sites reveal a positive fold test at the 99% confidence limit, indicating that the high-temperature magnetization component is possibly of Eocene age. A tilt-corrected mean direction from nine accepted sites is D=266.1°, I=-39.8° with α95=11.2°, corresponding to a paleopole at 14.5°N, 169.7°E with A95=10.9°. A comparison with previously reported Tertiary paleomagnetic data indicates that the Lanping basin of the northern part of the Indochina block rotated clockwise through 91° (±15°) with respect to the Yangtze craton. This large magnitude clockwise rotation is probably caused by the superimposition of regional and local rotations. Our previous middle Cretaceous paleomagnetic results from the Yunlong area indicate that about 40° of clockwise rotation out of 90° is explained by tectonic rotation due to a relatively rigid body rotation of the Simao Terrane during indentation of India. The remaining component of rotation is probably ascribed to further Eocene/post-Eocene rotational motion of the tectonically independent small blocks within the Lanping basin associated with fault movement.

  14. Mutational analysis of BRCA1/2 gene and pathologic characteristics from Kazakh population with sporadic breast cancer in northwestern China.

    PubMed

    Yang, S Y; Aisimutula, D; Li, H F; Hu, Y; Du, X; Li, J; Luan, M X

    2015-10-27

    Mutations in the BRCA1/2 genes are associated with an increased risk of breast cancer, but no large-scale research have examined the BRCA1/2 mutations in Chinese Kazakh women. We evaluated the frequency and distributions of BRCA1 and BRCA2 gene mutations in Kazakh sporadic breast cancer patients and healthy women in China. The association between the clinical-pathologic features of Kazakh breast cancer patients and BRCA1/2 mutations were also investigated. Two unclassified variants (T539M and T1915M) and 16 polymorphisms were detected in this study, 4 of which (G356A, His743, Asn991Asp, Val1269) were detected more frequently in breast cancer patients than in healthy controls. We observed a higher prevalence of BRCA1/2 common sequence alterations and a large number of Kazakh women carrying multiple co-existing BRCA1/2 mutations. The prevalence of BRCA1 mutations was similar to that of BRCA2 mutations. Although no significant differences were observed, BRCA1/2 carriers were generally younger at diagnosis of wild-type breast cancer patients. BRCA1-associated Kazakh sporadic breast cancers present with high tumor grade, early stage, negative lymph node status, absence of estrogen receptor expression and progesterone-positive status. Estrogen receptor expression was the only predominant histological type in BRCA2 carriers. In this study, we determined the BRCA1 and BRCA2 gene mutation status and determined the association with clinical-pathologic characteristics in a Chinese Kazakh population. Larger population-based screening studies screening the entire coding region of BRCA1/2 are required to evaluate the breast cancer risk induced by the sequence alterations detected in this study.

  15. Seed Dormancy, Seedling Establishment and Dynamics of the Soil Seed Bank of Stipa bungeana (Poaceae) on the Loess Plateau of Northwestern China

    PubMed Central

    Hu, Xiao Wen; Wu, Yan Pei; Ding, Xing Yu; Zhang, Rui; Wang, Yan Rong; Baskin, Jerry M.; Baskin, Carol C.

    2014-01-01

    Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls), chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling emergence was monitored weekly for 8 weeks. Furthermore, seeds were buried at different soil depths, and then retrieved every 1 or 2 months to determine seed dormancy and seed viability in the laboratory. Fresh seeds (caryopses enclosed by palea and lemma) had non-deep physiological dormancy. Removal of palea and lemma, chemical scarification, dry storage (afterripening), gibberellin (GA3) and potassium nitrate (KNO3) significantly improved germination. Dormancy was completely released by removal of the hulls, but seeds on which hulls were put back to their original position germinated to only 46%. Pretreatment of seeds with a 30% NaOH solution for 60 min increased germination from 25% to 82%. Speed of seedling emergence from fresh seeds was significantly lower than that of seeds stored for 1 year. However, final percentage of seedling emergence did not differ significantly for seeds sown at depths of 0 and 1 cm. Most fresh seeds of S. bungeana buried in the field in early July either had germinated or lost viability by September. All seeds buried at a depth of 5 cm had lost viability after 5 months, whereas 12% and 4% seeds of those sown on the soil surface were viable after 5 and 12 months, respectively. PMID:25396423

  16. A tree-ring based precipitation reconstruction for the Mohe region in the northern Greater Higgnan Mountains, China, since AD 1724

    NASA Astrophysics Data System (ADS)

    Zhang, Tongwen; Yuan, Yujiang; Wei, Wenshou; Yu, Shulong; Zhang, Ruibo; Chen, Feng; Shang, Huaming; Qin, Li

    2014-07-01

    August-July precipitation has been reconstructed back to AD 1724 for the Mohe region in the northern Greater Higgnan Mountains, China, using Pinus sylvestris var. mongolica tree-ring width. The reconstruction explains 39% of the variance in the precipitation observed from AD 1960-2008. Some droughts noted in historical documents are precisely captured in our reconstruction. Wet periods occurred during the periods of AD 1734-1785, AD 1805-1830, AD 1863-1880, AD 1922-1961, and AD 1983-1998; while the periods of AD 1786-1804, AD 1831-1862, AD 1881-1921, and AD 1962-1982 were relatively dry. Power spectral and wavelet analyses demonstrated the existence of significant 24-yr, 12-yr, and 2-yr cycles of variability. The results of the spatial correlations suggest that our reconstruction contains climatic signals for the southern Stanovoy Range and the northern Greater Higgnan Mountains. The positive correlations between the new reconstructed precipitation series and two precipitation reconstructions indicate that our precipitation reconstruction captures broad-scale regional climatic variations. A comparison between the weakening tendency of summer monsoon and the dry period of our reconstruction reveals that the annual precipitation in the Mohe region is partly influenced by the East Asian Summer Monsoon.

  17. Altitudinal Gradient of Microbial Biomass Phosphorus and Its Relationship with Microbial Biomass Carbon, Nitrogen, and Rhizosphere Soil Phosphorus on the Eastern Slope of Gongga Mountain, SW China

    PubMed Central

    Sun, Hongyang; Wu, Yanhong; Yu, Dong; Zhou, Jun

    2013-01-01

    Microbial biomass phosphorus (MBP) is one of the most active forms of phosphorus (P) in soils. MBP plays an important role in the biogeochemical P cycle. To explore MBP distribution and its relationship with other factors, the MBP and rhizosphere soil P concentrations and fractions in six vegetation zones on the eastern slope of Gongga Mountain in SW China were investigated. The MBP distribution followed a parabolic pattern with altitude and the concentration was highest in the subalpine dark coniferous forest (SDC) zone, which was approximately 3500 m above sea level (asl). Below 3500 m asl, the MBP distribution was controlled by precipitation and vegetation type. In addition, temperature, precipitation and vegetation type controlled the MBP distribution at elevations above 3500 m asl. No specific distribution pattern was determined regarding rhizosphere soil P fractions. However, MBP was significantly correlated with the unavailable P fraction in the rhizosphere rather than with the available P fraction. This result suggests that the relationships between the rhizosphere soil P fractions and the MBP depend on time. The microbial biomass element ratios were relatively consistent on the eastern slope of Gongga Mountain. However, variations in the microbial biomass element rations were observed in six of the vegetation zones. The mean C:N:P ratio was 9.0∶1.3∶1. Overall, vegetation type resulted in the observed fluctuations of the microbial biomass element ratio. PMID:24039830

  18. Effect of temperature and moisture on soil organic carbon mineralization of predominantly permafrost peatland in the Great Hing'an Mountains, northeastern China.

    PubMed

    Wang, Xianwei; Li, Xiuzhen; Hu, Yuanman; Lv, Jiujun; Sun, Ju; Li, Zongmei; Wu, Zhifeng

    2010-01-01

    Boreal peatlands represent a large global carbon pool. The relationships between carbon mineralization, soil temperature and moisture in the permafrost peatlands of the Great Hing'an Mountains, China, were examined. The CO2 emissions were measured during laboratory incubations of samples from four sites under different temperatures (5, 10, 15, and 20 degrees C) and moisture contents (0%, 30%, 60%, 100% water holding capacity (WHC) and completely water saturated). Total carbon mineralization ranged from 15.51 to 112.92 mg C under the treatments for all sites. Carbon mineralization rates decreased with soil depth, increased with temperature, and reached the highest at 60% WHC at the same temperature. The calculated temperature coefficient (Q10) values ranged from 1.84 to 2.51 with the soil depths and moisture. However, the values were not significantly affected by soil moisture and depth for all sites due to the different peat properties (P > 0.05). We found that the carbon mineralization could be successfully predicted as a two-compartment function with temperature and moisture (R2 > 0.96) and total carbon mineralization was significantly affected by temperature and moisture (P < 0.05). Thus, temperature and moisture would play important roles in carbon mineralization of permafrost peatlands in the Great Hing'an Mountains, indicating that the permafrost peatlands would be sensitive to the environment change, and the permafrost peatlands would be potentially mineralized under future climate change.

  19. Long-range atmospheric transport of persistent organochlorinated compounds from south and mainland south-eastern Asia to a remote mountain site in south-western China.

    PubMed

    Xu, Yue; Zhang, Gan; Li, Jun; Chakraborty, Paromita; Li, Hua; Liu, Xiang

    2011-11-01

    A range of organochlorinated compounds have been consumed in China, India and the countries of mainland southeast Asia (MSA). Considering their persistence in the environment and ability in long-range atmospheric transport (LRAT), the potential outflow of these compounds from this region is therefore of great concern in the context of the global distribution of toxic chemicals. As part of a monitoring campaign aimed at investigating the LRAT of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) from southern China, MSA and northern India, atmospheric levels of OCPs and PCBs were measured once a week from October 2005 through December 2006 at Tengchong Mountain (TM), a remote site located in south-western China. The average concentrations of OCPs were found to be higher than those in other remote stations in the Arctic and the Tibetan plateau, except for α-hexachlorocyclohexane (α-HCH). A high level of β-HCH and low α-HCH/β-HCH ratio was attributed to an accidental release of β-HCH from unknown sources, besides obvious evidence of lindane (γ-HCH) and technical HCH usage. Temporal variations of chlordanes and endosulfan were related to the usage pattern of these compounds, as well as LRAT. In contrast, dichlorodiphenyltrichloroethane (DDT) exhibited a relatively minor seasonal variation. The OCP levels at the monitoring site were found to be related to the air parcel back trajectories on the basis of four distinct clusters. Elevated levels of HCHs and DDTs were observed when air parcels originated from northern India where considerable OCP usage was reported recently, while high levels of γ-HCH and TC (trans-chlordane) were mainly associated with air masses from southern China and northern MSA. The study highlighted the high background level of OCPs as well as their temporal patterns of trans-boundary LRAT in the MSA region. PMID:21952469

  20. Tectonics, basin analysis and organic geochemical attributes of Permian through Mesozoic deposits and their derivative oils of the Turpan-Hami basin, northwestern China

    NASA Astrophysics Data System (ADS)

    Greene, Todd Jeremy

    The Turpan-Hami basin is a major physiographic and geologic feature of northwest China, yet considerable uncertainty exists as to the timing of its inception, its late Paleozoic and Mesozoic tectonic history, and the relationship of its petroleum systems to those of the nearby Junggar basin. Mesozoic sedimentary fades, regional unconformities, sediment dispersal patterns, and sediment compositions within the Turpan-Hami and southern Junggar basins suggest that these basins were initially separated between Early Triassic and Early Jurassic time. Prior to separation, Upper Permian profundal lacustrine and fan-delta fades and Triassic coarse-grained braided-fluvial/alluvial fades were deposited across a contiguous Junggar-Turpan-Hami basin. Permian through Triassic fades were derived mainly from the Tian Shan to the south as indicated by northward-directed paleocurrent directions and geochemical provenance of granitoid cobbles. Lower through Middle Jurassic strata begin to reflect ponded coal-forming, lake-plain environments within the Turpan-Hami basin. A sharp change in sedimentary-lithic-rich Lower Jurassic sandstone followed by a return to lithic volcanic-rich Middle Jurassic sandstone points to the initial uplift and unroofing of the largely andesitic Bogda Shan range, which first shed its sedimentary cover as it emerged to become the partition between the Turpan-Hami and southern Junggar basins. In Turpan-Hami, source rock age is one of three major statistically significant discriminators of effective source rocks in the basin. A newly developed biomarker parameter appears to track conifer evolution and can distinguish Permian rocks and their correlative oils from Jurassic coals and mudrocks, and their derivative oils. Source fades is a second key control on petroleum occurrence and character. By erecting rock-to-oil correlation models, the biomarker parameters separate oil families into end-member groups: Group 1 oils---Lower/Middle Jurassic peatland

  1. Spatio-temporal variations and influencing factors of polycyclic aromatic hydrocarbons in atmospheric bulk deposition along a plain-mountain transect in western China

    NASA Astrophysics Data System (ADS)

    Xing, Xinli; Zhang, Yuan; Yang, Dan; Zhang, Jiaquan; Chen, Wei; Wu, Chenxi; Liu, Hongxia; Qi, Shihua

    2016-08-01

    Ten atmospheric bulk deposition (the sum of wet and dry deposition) samplers for polycyclic aromatic hydrocarbons (PAHs) were deployed at a plain-mountain transect (namely PMT transect, from Daying to Qingping) in Chengdu Plain, West China from June 2007 to June 2008 in four consecutive seasons (about every three months). The bulk deposition fluxes of ∑15-PAHs ranged from 169.19 μg m-2 yr-1 to 978.58 μg m-2 yr-1 with geometric mean of 354.22 μg m-2 yr-1. The most prevalent PAHs were 4-ring (39.65%) and 3-ring (35.56%) PAHs. The flux values were comparable to those in rural areas. Higher fluxes of total PAHs were observed in the middle of PMT transect (SL, YX and JY, which were more urbanized than other sites). The seasonal deposition fluxes in the sampling profile indicated seasonality of the contaminant source was an important factor in controlling deposition fluxes. PAHs bulk deposition was negatively correlated with meteorological parameters (temperature, wind speed, humidity, and precipitation). No significant correlations between soil concentrations and atmospheric deposition were found along this transect. PAHs in soil samples had combined sources of coal, wood and petroleum combustion, while a simple source of coal, wood and grass combustion for bulk deposition. There were significant positive correlation relationship (p < 0.05) between annual atmospheric bulk deposition and local PAHs emission, with biomass burning as the major contribution to the total emission of PAHs. This transect acts as an important PAHs source rather than being a sink according to the ratio of deposition/emission. Mountain cold trap effect existed in this transect where the altitude was higher than 1000 m. Long-range transport had an impact on the bulk deposition in summer. And this transect was a source to Tibetan only in summer. The forward trajectory analysis showed most air masses did not undergo long-range transport due to the blocking effect of surrounding mountains. Only

  2. Fluid inclusion, rare earth element geochemistry, and isotopic characteristics of the eastern ore zone of the Baiyangping polymetallic Ore district, northwestern Yunnan Province, China

    NASA Astrophysics Data System (ADS)

    Feng, Caixia; Bi, Xianwu; Liu, Shen; Hu, Ruizhong

    2014-05-01

    The Baiyangping Cu-Ag polymetallic ore district is located in the northern part of the Lanping-Simao foreland fold belt, which lies between the Jinshajiang-Ailaoshan and Lancangjiang faults in western Yunnan Province, China. The source of ore-forming fluids and materials within the eastern ore zone were investigated using fluid inclusion, rare earth element (REE), and isotopic (C, O, and S) analyses undertaken on sulfides, gangue minerals, wall rocks, and ores formed during the hydrothermal stage of mineralization. These analyses indicate: (1) The presence of five types of fluid inclusion, which contain various combinations of liquid (l) and vapor (v) phases at room temperature: (a) H2O (l), (b) H2O (l) + H2O (v), (c) H2O (v), (d) CmHn (v), and (e) H2O (l) + CO2 (l), sometimes with CO2 (v). These inclusions have salinities of 1.4-19.9 wt.% NaCl equivalents, with two modes at approximately 5-10 and 16-21 wt.% NaCl equivalent, and homogenization temperatures between 101 °C and 295 °C. Five components were identified in fluid inclusions using Raman microspectrometry: H2O, dolomite, calcite, CH4, and N2. (2) Calcite, dolomitized limestone, and dolomite contain total REE concentrations of 3.10-38.93 ppm, whereas wall rocks and ores contain REE concentrations of 1.21-196 ppm. Dolomitized limestone, dolomite, wall rock, and ore samples have similar chondrite-normalized REE patterns, with ores in the Huachangshan, Xiaquwu, and Dongzhiyan ore blocks having large negative δCe and δEu anomalies, which may be indicative of a change in redox conditions during fluid ascent, migration, and/or cooling. (3) δ34S values for sphalerite, galena, pyrite, and tetrahedrite sulfide samples range from -7.3‰ to 2.1‰, a wide range that indicates multiple sulfur sources. The basin contains numerous sources of S, and deriving S from a mixture of these sources could have yielded these near-zero values, either by mixing of S from different sources, or by changes in the geological

  3. How do two giant panda populations adapt to their habitats in the Qinling and Qionglai Mountains, China.

    PubMed

    Liu, Xuehua; Wang, Tiejun; Wang, Ting; Skidmore, Andrew K; Songer, Melissa

    2015-01-01

    The spatial separation of the Qinling Mountains from the western mountains has caused morphological and genetic distinctions of giant pandas. Could this separation also cause the pandas' behavior change? In this research, we focused on the pandas' movement pattern and selected two wild panda groups in Foping and Wolong Nature Reserves (NR) to represent the populations in the Qinling and Qionglai Mountains, respectively. We hypothesized that the Qinling pandas have developed a different seasonal movement pattern compared with the pandas in the western mountains. We analyzed the radio tracking data from two NRs by using GIS. Our results showed the following significant differences: (1) The Foping pandas live most of the year in the low elevation areas and move higher during June and remain through August while the Wolong pandas live most of the year in the high elevation areas and move lower in April and stay through June; (2) Comparing their low and high elevational areas shows the distinct spatial patterns between reserves, forming two obviously separated clusters in Foping but a single-compact cluster in Wolong; (3) Foping pandas move an average of 425 m ± 147 s.d. daily, while Wolong pandas move an average of 550 m ± 343 s.d. daily; and (4) Three habitat factors (i.e., terrain, temperature, and bamboo nutrient) were taken as the driving forces and analyzed, and they showed a strong support explanation to these different movement behaviors of pandas in two NRs. Our findings have important implications for management, for instance, it needs to be careful considering the behavior difference of the pandas when reintroducing them to the wild. PMID:25119280

  4. How do two giant panda populations adapt to their habitats in the Qinling and Qionglai Mountains, China.

    PubMed

    Liu, Xuehua; Wang, Tiejun; Wang, Ting; Skidmore, Andrew K; Songer, Melissa

    2015-01-01

    The spatial separation of the Qinling Mountains from the western mountains has caused morphological and genetic distinctions of giant pandas. Could this separation also cause the pandas' behavior change? In this research, we focused on the pandas' movement pattern and selected two wild panda groups in Foping and Wolong Nature Reserves (NR) to represent the populations in the Qinling and Qionglai Mountains, respectively. We hypothesized that the Qinling pandas have developed a different seasonal movement pattern compared with the pandas in the western mountains. We analyzed the radio tracking data from two NRs by using GIS. Our results showed the following significant differences: (1) The Foping pandas live most of the year in the low elevation areas and move higher during June and remain through August while the Wolong pandas live most of the year in the high elevation areas and move lower in April and stay through June; (2) Comparing their low and high elevational areas shows the distinct spatial patterns between reserves, forming two obviously separated clusters in Foping but a single-compact cluster in Wolong; (3) Foping pandas move an average of 425 m ± 147 s.d. daily, while Wolong pandas move an average of 550 m ± 343 s.d. daily; and (4) Three habitat factors (i.e., terrain, temperature, and bamboo nutrient) were taken as the driving forces and analyzed, and they showed a strong support explanation to these different movement behaviors of pandas in two NRs. Our findings have important implications for management, for instance, it needs to be careful considering the behavior difference of the pandas when reintroducing them to the wild.

  5. Geometry and late Pleistocene slip rates of the Liangdang-Jiangluo fault in the western Qinling mountains, NW China

    NASA Astrophysics Data System (ADS)

    Wen-jun, Zheng; Xing-wang, Liu; Jing-xing, Yu; Dao-yang, Yuan; Pei-zhen, Zhang; Wei-peng, Ge; Jian-zhang, Pang; Bai-yun, Liu

    2016-09-01

    Two groups of faults striking in different direction (NWW-trending and NEE-trending) within the western Qinling mountains play important roles in the tectonic deformation and the transference slip along the east end of the east Kunlun fault. We investigated the fault geometry and kinematics properties in the area. Based on the displacements of landforms and optically stimulated luminescence (OSL) dating techniques, the late Pleistocene slip rates along the Liangdang-Jiangluo fault were determined to be 0.43 ± 0.13 mm/a (thrust) and 0.71 ± 0.18 mm/a (left-lateral strike-slip). We also investigated some other faults, and obtained characteristically low slip rates. These slip rates are consistent with decadal GPS observations. Despite previous studies that point to a systematic decrease in the left-lateral slip rates from > 10 mm/a to < 2 mm/a along the eastern end of the Kunlun fault, there has been relatively little discussion about the role of the faults, that lie between the east Kunlun and west Qinling faults in accommodating the regional tectonic deformation. From the activity, geometry, and kinematics of the regional faults in the western Qinling Mountains, we concluded that the main driving force that arises from the NE-thrusting and strike slip along the east Kunlun fault dominated the deformation in the area. Our results suggest that the < 2 mm/a slip rate at the tip of the east Kunlun fault is absorbed by low slip rate faults, crustal shortening, basin formation and mountain uplift in the western Qinling mountains, and the slip is not transferred to the west Qinling fault or further north.

  6. [Observational study of formaldehyde in air, rain and fog water at a site on the Mangdang Mountain of Fujian, China].

    PubMed

    Wang, Xiao-yan; Wang, Hui-xiang; Ma, Yi-yuan

    2010-08-01

    Through 2,4-dinitrophenylhydrazine (DNPH) high-performance liquid chromatography (HPLC) method, the levels of formaldehyde in ambient air, rain and fog samples were measured in Mangdang Mountain, Fujian Province, from March to April 2009. The average concentrations of formaldehyde in ambient air, rain and fog are 4.0 x 10(-10), 2.19 micromol/L and 2.94 micromol/L, respectively. Based on previous researches, this study described formaldehyde hydrolysis and reacting with S(IV) and other chemical reaction processes in liquid phase, explaining the phenomenon that the solubility of formaldehyde in the liquid phase is higher than the theoretical value. On-site measured Henry coefficients (Hme) and the effective Henry coefficients (H*) were derived from concentration of formaldehyde in ambient air, rain and fog samples and references. Comparing Hme and H*, this study found that the measured liquid phase concentrations of formaldehyde are higher than the theoretical concentrations, consistent with the references. The further founding is that Hme/H* in fog is higher than in rain, proving the result of Mangdang Mountain that the concentration of formaldehyde in fog is higher than in rain. Considering the climatic characteristics of Mangdang Mountain in spring, the wet deposition of formaldehyde is an important way in this area.

  7. [Butterfly diversity and faunal characteristics on the south slope of Taibai Mountain, Shaanxi Province of Northwest China].

    PubMed

    Gao, Ke; Fang, Li-Jun; Shang, Su-Qin; Zhang, Ya-Lin

    2013-06-01

    An investigation was conducted on the butterflies on the south slope of Taibai Mountain from April to October, 2009, with their diversity index, evenness index, dominance index, and species richness calculated and analyzed. A total of 126 species were recorded, belonging to 77 genera and 5 families. Nymphalidae had the highest diversity index (3.3621) and species richness (9.9363), and Pieridae had the highest dominance index (0.0573) and evenness index (0.8352). The genera and species were most abundant in June-August, the diversity index was the highest in July (3.4094), and the species richness was the highest in August (10.7). The bio-geographic component analysis of 124 species (other 2 species were not identified) showed that the widely distributed species were most abundant (51 species), occupying 40.5% of the total, followed by Palaearctic species (41 species), occupying 32.5%, and Oriental species were the least (32 species), occupying 25.4%, which suggested that Taibai Mountain could be the transitional area of Palearctic and Oriental regions. The comparative analysis of the butterfly diversity and faunal characteristics on the south and north slopes of Taibai Mountain showed that there were 85 shared species, and the similarity coefficient was 62.0%, indicating that the butterfly fauna had definite difference between the two slopes though they were geographically in proximity.

  8. Characteristics of night-time sleeping places selected by golden monkeys (Rhinopithecus bieti) in the Samage Forest, Baima Snow Mountain Nature Reserve, China.

    PubMed

    Li, Dayong; Grueter, Cyril C; Ren, Baoping; Zhou, Qihai; Li, Ming; Peng, Zhengsong; Wei, Fuwen

    2006-12-01

    We examined the criteria for sleeping place selection in a social band of Rhinopithecus bieti (black-and-white snub-nosed or golden monkeys) living in the mountainous Samage Forest, Baima Snow Mountain Nature Reserve, Yunnan, China. We performed principal component analysis and found that slope aspect, tree height and trunk diameter were likely key variables influencing selection of sleeping places. Sleeping sites were preferentially located in mixed deciduous/conifer forest. The monkeys slept exclusively in evergreen trees, of which 82% were conifers (mostly Picea likiangensis and Tsuga dumosa) and 18% evergreen oaks (Cyclobalanopsis oxyodon and Quercus spp.). Sleeping trees were tall (mean 30.5 m), had high boles (mean 18.4 m), large diameters (mean 62.6 cm) and large crown areas (mean 57.9 m(2) ). A comparative analysis of phytological and architectural features between trees in "sleeping site plots" (n= 18) and trees in "non-sleeping-site plots" (n= 66) revealed that diameter, crown surface area and tree height were significantly (P < 0.01) larger in the former compared with the latter. All investigated roosting sites were situated on steep mountain slopes. Valleys and mountain ridges were avoided. We also detected re-use of roosting sites on several occasions, but not on consecutive nights. It is most likely that a mix of factors (stability of trees, access to food, unit cohesion, monitoring potential) explains the pattern of sleeping site preference, but predation at night seems to be only slightly important. Climate appears to have a profound influence on patterns of sleeping site selection in the monkeys' harsh temperate habitat. This is demonstrated by the monkeys' preference for mixed forest at medium elevations over montane fir forest at high elevations and slopes instead of ridges, with reduced exposure to wind and precipitation inherent in the former. We also emphasize the possibly substantial role that non-environmental factors (the nature of social

  9. Blastomycosis in Northwestern Ontario

    PubMed Central

    McIntyre, Lynn

    1985-01-01

    Nine cases of blastomycosis were seen at the Sioux Lookout Zone Hospital in northwestern Ontario from 1970 to 1983. Although this region has been described as a focus of endemic infection, little published information is available. Seven male and two female Canadian Indians, aged 4-54 years, acquired the infection. Three children were infected; a mother and her son became ill one month apart. All cases presented as progressive pulmonary disease and no extrapulmonary involvement was found. Delay in diagnosis ranged from 11 days to eight weeks, with a mean of 31 days. Patients generally responded favorably to treatment with amphotericin B. Epidemiologic data suggest that environmental, geographic, occupational and recreational determinants are necessary factors in disease acquisition. PMID:21279155

  10. Biogenic Iron-Rich Filaments in the Quartz Veins in the Uppermost Ediacaran Qigebulake Formation, Aksu Area, Northwestern Tarim Basin, China: Implications for Iron Oxidizers in Subseafloor Hydrothermal Systems.

    PubMed

    Zhou, Xiqiang; Chen, Daizhao; Tang, Dongjie; Dong, Shaofeng; Guo, Chuan; Guo, Zenghui; Zhang, Yanqiu

    2015-07-01

    Fe-(oxyhydr)oxide-encrusted filamentous microstructures produced by microorganisms have been widely reported in various modern and ancient extreme environments; however, the iron-dependent microorganisms preserved in hydrothermal quartz veins have not been explored in detail because of limited materials available. In this study, abundant well-preserved filamentous microstructures were observed in the hydrothermal quartz veins of the uppermost dolostones of the terminal-Ediacaran Qigebulake Formation in the Aksu area, northwestern Tarim Basin, China. These filamentous microstructures were permineralized by goethite and hematite as revealed by Raman spectroscopy and completely entombed in chalcedony and quartz cements. Microscopically, they are characterized by biogenic filamentous morphologies (commonly 20-200 μm in length and 1-5 μm in diameter) and structures (curved, tubular sheath-like, segmented, and mat-like filaments), similar to the Fe-oxidizing bacteria (FeOB) living in modern and ancient hydrothermal vent fields. A previous study revealed that quartz-barite vein swarms were subseafloor channels of low-temperature, silica-rich, diffusive hydrothermal vents in the earliest Cambrian, which contributed silica to the deposition of the overlying bedded chert of the Yurtus Formation. In this context, this study suggests that the putative filamentous FeOB preserved in the quartz veins might have thrived in the low-temperature, silica- and Fe(II)-rich hydrothermal vent channels in subseafloor mixing zones and were rapidly fossilized by subsequent higher-temperature, silica-rich hydrothermal fluids in response to waning and waxing fluctuations of diffuse hydrothermal venting. In view of the occurrence in a relatively stable passive continental margin shelf environment in Tarim Block, the silica-rich submarine hydrothermal vent system may represent a new and important geological niche favorable for FeOB colonization, which is different from their traditional

  11. Biogenic Iron-Rich Filaments in the Quartz Veins in the Uppermost Ediacaran Qigebulake Formation, Aksu Area, Northwestern Tarim Basin, China: Implications for Iron Oxidizers in Subseafloor Hydrothermal Systems.

    PubMed

    Zhou, Xiqiang; Chen, Daizhao; Tang, Dongjie; Dong, Shaofeng; Guo, Chuan; Guo, Zenghui; Zhang, Yanqiu

    2015-07-01

    Fe-(oxyhydr)oxide-encrusted filamentous microstructures produced by microorganisms have been widely reported in various modern and ancient extreme environments; however, the iron-dependent microorganisms preserved in hydrothermal quartz veins have not been explored in detail because of limited materials available. In this study, abundant well-preserved filamentous microstructures were observed in the hydrothermal quartz veins of the uppermost dolostones of the terminal-Ediacaran Qigebulake Formation in the Aksu area, northwestern Tarim Basin, China. These filamentous microstructures were permineralized by goethite and hematite as revealed by Raman spectroscopy and completely entombed in chalcedony and quartz cements. Microscopically, they are characterized by biogenic filamentous morphologies (commonly 20-200 μm in length and 1-5 μm in diameter) and structures (curved, tubular sheath-like, segmented, and mat-like filaments), similar to the Fe-oxidizing bacteria (FeOB) living in modern and ancient hydrothermal vent fields. A previous study revealed that quartz-barite vein swarms were subseafloor channels of low-temperature, silica-rich, diffusive hydrothermal vents in the earliest Cambrian, which contributed silica to the deposition of the overlying bedded chert of the Yurtus Formation. In this context, this study suggests that the putative filamentous FeOB preserved in the quartz veins might have thrived in the low-temperature, silica- and Fe(II)-rich hydrothermal vent channels in subseafloor mixing zones and were rapidly fossilized by subsequent higher-temperature, silica-rich hydrothermal fluids in response to waning and waxing fluctuations of diffuse hydrothermal venting. In view of the occurrence in a relatively stable passive continental margin shelf environment in Tarim Block, the silica-rich submarine hydrothermal vent system may represent a new and important geological niche favorable for FeOB colonization, which is different from their traditional

  12. New flavan-3-ol dimer from green tea produced from Camellia taliensis in the Ai-Lao mountains of Southwest China.

    PubMed

    Zhu, Li-Fang; Xu, Min; Zhu, Hong-Tao; Wang, Dong; Yang, Shi-Xiong; Yang, Chong-Ren; Zhang, Ying-Jun

    2012-12-12

    Camellia taliensis (W. W. Smith) Melchior, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic species distributed from the west and southwest of Yunnan province, China, to the north of Myanmar. Known as a wild tea tree, its leaves have been used commonly for producing tea beverages by the local people of its growing area. One new flavan-3-ol dimer, talienbisflavan A (1), was isolated from green tea prepared from the leaves of C. taliensis collected from the east side of the Ai-Lao mountains, Yuanjiang county of Yunnan province, China. In addition, five hydrolyzable tannins (2-6), five flavonols and flavonol glycosides (9-13), three flavan-3-ols (14-16), nine simple phenolic compounds and glycosides (7, 8, and 17-23), and caffeine (24) were identified. Their structures were determined by detailed spectroscopic analysis. All of the isolated phenolic compounds were tested for their antioxidant activities by DPPH and ABTS(+) radical scavenging assays. The contents of its main chemical compositions were also compared with those collected from the Lincang area of Yunnan province by high-performance liquid chromatography analysis. PMID:23167720

  13. MISR Images Wildfires in Northwestern US

    NASA Technical Reports Server (NTRS)

    2000-01-01

    MISR image of smoke plumes from devastating wildfires in the northwestern US. This view of the Clearwater and Salmon River Mountains in Idaho was acquired on August 5, 2000 (Terra orbit 3370). The body of water to the left of image center is the Cascade Reservoir, located about 100 km north of Boise and 80 km east of the Snake River. North is at the top, and the image is approximately 380 km across.

    In addition to the huge plumes traversing the mountains in the northern part of the image, smoke accumulating in the lower elevation canyons and plains is visible. This image was generated using data from the MISR camera that looks forward at a steep angle (70.5 degrees). The smoke is far more visible when viewed at this highly oblique angle than it would be in a conventional, straight-downward view. In creating this color composite, data from the blue and green MISR bands, acquired at 1.1-km spatial resolution, were digitally 'sharpened' using 275-m resolution data acquired in the red band.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

    For more information: http://www-misr.jpl.nasa.gov

  14. [Spatial pattern of forest biomass and its influencing factors in the Great Xing'an Mountains, Heilongjiang Province, China].

    PubMed

    Wang, Xiao-Li; Chang, Yu; Chen, Hong-Wei; Hu, Yuan-Man; Jiao, Lin-Lin; Feng, Yu-Ting; Wu, Wen; Wu, Hai-Feng

    2014-04-01

    Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing'an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing'an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t x hm(-2)) was higher than that in the temperate humid zone (60.26 t x hm(-2)). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t x hm(-2)) > spruce-fir forest (63.92 t x hm(-2)) > Pinus pumila-Larix gmelinii forest (63.79 t x hm(-2)) > Pinus sylvestris var. mongolica forest (61.97 t x hm(-2)) > Larix gmelinii forest (61.40 t x hm(-2)) > deciduous broadleaf forest (58.96 t x hm(-2)). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing' an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales. PMID:25011288

  15. [Spatial pattern of forest biomass and its influencing factors in the Great Xing'an Mountains, Heilongjiang Province, China].

    PubMed

    Wang, Xiao-Li; Chang, Yu; Chen, Hong-Wei; Hu, Yuan-Man; Jiao, Lin-Lin; Feng, Yu-Ting; Wu, Wen; Wu, Hai-Feng

    2014-04-01

    Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing'an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing'an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t x hm(-2)) was higher than that in the temperate humid zone (60.26 t x hm(-2)). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t x hm(-2)) > spruce-fir forest (63.92 t x hm(-2)) > Pinus pumila-Larix gmelinii forest (63.79 t x hm(-2)) > Pinus sylvestris var. mongolica forest (61.97 t x hm(-2)) > Larix gmelinii forest (61.40 t x hm(-2)) > deciduous broadleaf forest (58.96 t x hm(-2)). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing' an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales.

  16. Numerical study of a downslope windstorm in Northwestern Greece

    NASA Astrophysics Data System (ADS)

    Koletsis, I.; Lagouvardos, K.; Kotroni, V.; Bartzokas, A.

    2009-10-01

    This paper describes the leeside wind storm of 25-26 March 1998, the most intense wind storm of the last decade in Northwestern Greece. This wind storm produced wind gusts of ˜ 30 m s - 1 that resulted in tree uprooting, roof damaging, electric power network disruption and flooding in the lake-side areas of Ioannina city in Northwestern Greece. With the aim to identify the role of Mountain Mitsikeli near the city of Ioannina on the windstorm and to investigate the physical mechanisms responsible for such orographically induced weather events, numerical simulations with MM5 model have been performed. The model results showed that a resolution of 2-km resolution is necessary in order to reproduce the localized character of the wind storm. The analysis revealed that a synergistic combination of the cross-barrier northeasterly flow, the stable layer above the mountain top and the presence of a critical level, led to the intensification of the lee side winds during the studied wind event. Sensitivity experiments with modified topography, further supported the important role of mountain Mitsikeli that stands as an isolated obstacle, on the modification of the wind field during the observed windstorm.

  17. Why Do Primary School Students Drop out in Poor, Rural China? A Portrait Sketched in a Remote Mountain Village

    ERIC Educational Resources Information Center

    Chung, Carol; Mason, Mark

    2012-01-01

    In this paper we consider why students in poor and rural regions of China are dropping out of school in numbers that may be greater than official statistics admit. With questions about education quality among the most intractable in Education for All initiatives across the developing world, we sketch a portrait of education in a remote mountain…

  18. [Dendroclimatic potentials for the tree rings of Huangshan pine (Pinus taiwanensis ) at Xiaolinhai in the western Dabie Mountains, China].

    PubMed

    Peng, Jian-Feng; Li, Guo-Dong; Li, Ling-Ling

    2014-07-01

    By using the dendrochronology research methods, this paper developed the 1915-2011 tree ring-width standard chronology of the Huangshan pine (Pinus taiwanesis) at the north slope of western Dabie Mountains in the junction of Hubei, Henan and Anhui provinces. High mean sensitivity (MS) indicated that there was conspicuous high-frequency climate signals and high first-order autocorrelation (AC) showed there were significant lag-effects of tree previous growth. The higher signal-to-noise ratio (SNR) and expressed population signal (EPS) indicated that the trees had high levels of common climate signals. Correlations between the tree ring-width standard chronology and climatic factors (1959-2011) revealed the significant influences of temperature, precipitation and relative humidity on the tree width growth of Huangshan pine by the end of growing season (September and October). Significant positive correlations were found between the tree-ring indices and the Palmer drought severity index (PDSI) of current September and October. In conclusion, the combination of water and heat of September and October is the major effect factor for the growth of Huangshan pine in western Dabie Mountains.

  19. [Dendroclimatic potentials for the tree rings of Huangshan pine (Pinus taiwanensis ) at Xiaolinhai in the western Dabie Mountains, China].

    PubMed

    Peng, Jian-Feng; Li, Guo-Dong; Li, Ling-Ling

    2014-07-01

    By using the dendrochronology research methods, this paper developed the 1915-2011 tree ring-width standard chronology of the Huangshan pine (Pinus taiwanesis) at the north slope of western Dabie Mountains in the junction of Hubei, Henan and Anhui provinces. High mean sensitivity (MS) indicated that there was conspicuous high-frequency climate signals and high first-order autocorrelation (AC) showed there were significant lag-effects of tree previous growth. The higher signal-to-noise ratio (SNR) and expressed population signal (EPS) indicated that the trees had high levels of common climate signals. Correlations between the tree ring-width standard chronology and climatic factors (1959-2011) revealed the significant influences of temperature, precipitation and relative humidity on the tree width growth of Huangshan pine by the end of growing season (September and October). Significant positive correlations were found between the tree-ring indices and the Palmer drought severity index (PDSI) of current September and October. In conclusion, the combination of water and heat of September and October is the major effect factor for the growth of Huangshan pine in western Dabie Mountains. PMID:25345032

  20. Measurements of the surface energy budget in the southern Gobi Desert of China, and in the Rocky Mountains of Colorado

    NASA Technical Reports Server (NTRS)

    Reiter, E. R.; Smith, E. A.; Sheaffer, J. D.

    1985-01-01

    Observations of the land surface energy balance were made in the Gobi desert and at two mountain sites in northern Colorado. The Gobi study included 12 days of observations in spring (April 8 to 20, 1984) and 31 days in summer at the same site (June 17 to July 18, 1984). The Colorado study included 126 days (March 13 to July 17, 1984) at a valley site and 34 days (July 31 to September 3, 1984) at a mountain top location. The data for each study included continuous observations of upward and downward radiative fluxes in three wave bands, soil temperature and moisture at four levels, air temperature and humidity at four levels and UVW wind components at three levels. Analyses of the Gobi data include definition of the impact of variable atmospheric moisture on the surface energy balance between spring and summer. In addition, diurnal wind circulations forced by heating of the northern edge of the Tibetan Plateau were observed during both periods.

  1. Association of Soil Aggregation with the Distribution and Quality of Organic Carbon in Soil along an Elevation Gradient on Wuyi Mountain in China.

    PubMed

    Li, Liguang; Vogel, Jason; He, Zhenli; Zou, Xiaoming; Ruan, Honghua; Huang, Wei; Wang, Jiashe; Bianchi, Thomas S

    2016-01-01

    Forest soils play a critical role in the sequestration of atmospheric CO2 and subsequent attenuation of global warming. The nature and properties of organic matter in soils have an influence on the sequestration of carbon. In this study, soils were collected from representative forestlands, including a subtropical evergreen broad-leaved forest (EBF), a coniferous forest (CF), a subalpine dwarf forest (DF), and alpine meadow (AM) along an elevation gradient on Wuyi Mountain, which is located in a subtropical area of southeastern China. These soil samples were analyzed in the laboratory to examine the distribution and speciation of organic carbon (OC) within different size fractions of water-stable soil aggregates, and subsequently to determine effects on carbon sequestration. Soil aggregation rate increased with increasing elevation. Soil aggregation rate, rather than soil temperature, moisture or clay content, showed the strongest correlation with OC in bulk soil, indicating soil structure was the critical factor in carbon sequestration of Wuyi Mountain. The content of coarse particulate organic matter fraction, rather than the silt and clay particles, represented OC stock in bulk soil and different soil aggregate fractions. With increasing soil aggregation rate, more carbon was accumulated within the macroaggregates, particularly within the coarse particulate organic matter fraction (250-2000 μm), rather than within the microaggregates (53-250μm) or silt and clay particles (< 53μm). In consideration of the high instability of macroaggregates and the liability of SOC within them, further research is needed to verify whether highly-aggregated soils at higher altitudes are more likely to lose SOC under warmer conditions.

  2. Polyphase exhumation in the western Qinling Mountains, China: Rapid Early Cretaceous cooling along a lithospheric-scale tear fault and pulsed Cenozoic uplift

    PubMed Central

    Heberer, Bianca; Anzenbacher, Thomas; Neubauer, Franz; Genser, Johann; Dong, Yunpeng; Dunkl, István

    2014-01-01

    The western sector of the Qinling–Dabie orogenic belt plays a key role in both Late Jurassic to Early Cretaceous “Yanshanian” intracontinental tectonics and Cenozoic lateral escape triggered by India–Asia collision. The Taibai granite in the northern Qinling Mountains is located at the westernmost tip of a Yanshanian granite belt. It consists of multiple intrusions, constrained by new Late Jurassic and Early Cretaceous U–Pb zircon ages (156 ± 3 Ma and 124 ± 1 Ma). Applying various geochronometers (40Ar/39Ar on hornblende, biotite and K-feldspar, apatite fission-track, apatite [U–Th–Sm]/He) along a vertical profile of the Taibai Mountain refines the cooling and exhumation history. The new age constraints record the prolonged pre-Cenozoic intracontinental deformation as well as the cooling history mostly related to India–Asia collision. We detected rapid cooling for the Taibai granite from ca. 800 to 100 °C during Early Cretaceous (ca. 123 to 100 Ma) followed by a period of slow cooling from ca. 100 Ma to ca. 25 Ma, and pulsed exhumation of the low-relief Cretaceous peneplain during Cenozoic times. We interpret the Early Cretaceous rapid cooling and exhumation as a result from activity along the southern sinistral lithospheric scale tear fault of the recently postulated intracontinental subduction of the Archean/Palaeoproterozoic North China Block beneath the Alashan Block. A Late Oligocene to Early Miocene cooling phase might be triggered either by the lateral motion during India–Asia collision and/or the Pacific subduction zone. Late Miocene intensified cooling is ascribed to uplift of the Tibetan Plateau. PMID:27065503

  3. Association of Soil Aggregation with the Distribution and Quality of Organic Carbon in Soil along an Elevation Gradient on Wuyi Mountain in China

    PubMed Central

    Li, Liguang; Vogel, Jason; He, Zhenli; Zou, Xiaoming; Ruan, Honghua; Huang, Wei; Wang, Jiashe; Bianchi, Thomas S.

    2016-01-01

    Forest soils play a critical role in the sequestration of atmospheric CO2 and subsequent attenuation of global warming. The nature and properties of organic matter in soils have an influence on the sequestration of carbon. In this study, soils were collected from representative forestlands, including a subtropical evergreen broad-leaved forest (EBF), a coniferous forest (CF), a subalpine dwarf forest (DF), and alpine meadow (AM) along an elevation gradient on Wuyi Mountain, which is located in a subtropical area of southeastern China. These soil samples were analyzed in the laboratory to examine the distribution and speciation of organic carbon (OC) within different size fractions of water-stable soil aggregates, and subsequently to determine effects on carbon sequestration. Soil aggregation rate increased with increasing elevation. Soil aggregation rate, rather than soil temperature, moisture or clay content, showed the strongest correlation with OC in bulk soil, indicating soil structure was the critical factor in carbon sequestration of Wuyi Mountain. The content of coarse particulate organic matter fraction, rather than the silt and clay particles, represented OC stock in bulk soil and different soil aggregate fractions. With increasing soil aggregation rate, more carbon was accumulated within the macroaggregates, particularly within the coarse particulate organic matter fraction (250–2000 μm), rather than within the microaggregates (53–250μm) or silt and clay particles (< 53μm). In consideration of the high instability of macroaggregates and the liability of SOC within them, further research is needed to verify whether highly-aggregated soils at higher altitudes are more likely to lose SOC under warmer conditions. PMID:26964101

  4. Association of Soil Aggregation with the Distribution and Quality of Organic Carbon in Soil along an Elevation Gradient on Wuyi Mountain in China.

    PubMed

    Li, Liguang; Vogel, Jason; He, Zhenli; Zou, Xiaoming; Ruan, Honghua; Huang, Wei; Wang, Jiashe; Bianchi, Thomas S

    2016-01-01

    Forest soils play a critical role in the sequestration of atmospheric CO2 and subsequent attenuation of global warming. The nature and properties of organic matter in soils have an influence on the sequestration of carbon. In this study, soils were collected from representative forestlands, including a subtropical evergreen broad-leaved forest (EBF), a coniferous forest (CF), a subalpine dwarf forest (DF), and alpine meadow (AM) along an elevation gradient on Wuyi Mountain, which is located in a subtropical area of southeastern China. These soil samples were analyzed in the laboratory to examine the distribution and speciation of organic carbon (OC) within different size fractions of water-stable soil aggregates, and subsequently to determine effects on carbon sequestration. Soil aggregation rate increased with increasing elevation. Soil aggregation rate, rather than soil temperature, moisture or clay content, showed the strongest correlation with OC in bulk soil, indicating soil structure was the critical factor in carbon sequestration of Wuyi Mountain. The content of coarse particulate organic matter fraction, rather than the silt and clay particles, represented OC stock in bulk soil and different soil aggregate fractions. With increasing soil aggregation rate, more carbon was accumulated within the macroaggregates, particularly within the coarse particulate organic matter fraction (250-2000 μm), rather than within the microaggregates (53-250μm) or silt and clay particles (< 53μm). In consideration of the high instability of macroaggregates and the liability of SOC within them, further research is needed to verify whether highly-aggregated soils at higher altitudes are more likely to lose SOC under warmer conditions. PMID:26964101

  5. A 22 570 yr record of vegetational and climatic change from Wenhai Lake in the Hengduan Mountains biodiversity hotspot, Yunnan, Southwest China

    NASA Astrophysics Data System (ADS)

    Yao, Y. F.; Song, X. Y.; Wortley, A. H.; Blackmore, S.; Li, C. S.

    2014-09-01

    The Hengduan Mountains, with their strong altitudinal vegetation zonation, form a biodiversity hotspot which offers the potential for comparison between sites in order to understand how this zonation arose and how it has responded to climate change and human impacts through time. This paper is one of the studies covering a range of altitudes within this hotspot, and presents a 22 570 yr pollen record of vegetational and climatic change based on a core 320 cm in depth collected from Wenhai Lake on the Jade Dragon Snow Mountain, one of the highest peaks in the Hengduan Mountains region of Yunnan, Southwest China. From 22 570 to 21 140 cal. yr BP, the vegetation was dominated by broad-leaved forest (comprising mainly Quercus, Betula and Castanopsis), accompanied by coniferous Pinus and Abies and the drought-tolerant herb Artemisia, indicating a cool and dry climate. In the period between 21 140 and 19 350 cal. yr BP, the vegetation was still dominated by broad-leaved forest but with a notable increase in pollen of aquatic plants, implying a relatively warm and moderately humid climate. The period 19 350 to 17 930 cal. yr BP was a transition stage from broad-leaved forest to needle-leaved forest, reflecting a warm-humid climate at the beginning and a cold-dry one at the end. Between 17 930 and 9250 cal. yr BP, needle-leaved forest and broad-leaved forest alternated in dominance in the early stages, with the former taking the predominant position by the end of the period, suggesting a climate fluctuating between warm-humid and cold-dry. From 9250 cal. yr BP to present, the vegetation has been dominated by needle-leaved forest (comprising mainly Pinus and Abies), coupled with broad-leaved forest (mainly Quercus and Betula), reflecting a transition in climatic conditions from warm-humid to cold-humid. During this period, human activity increased in this region, with impacts on the vegetation which may be evidenced by the distinct decrease in Pinus and Quercus pollen and

  6. Progress, challenges and prospects of eco-hydrological studies in the Tarim river basin of Xinjiang, China.

    PubMed

    Chen, Yaning; Xu, Changchun; Chen, Yapeng; Liu, Yongbo; Li, Weihong

    2013-01-01

    Eco-hydrological research in arid inland river basins has been a focus of geologists and ecologists as it is crucial for maintaining the sustainable development of socio-economy, particularly in ecologically vulnerable areas. Based on the research work carried out in the Tarim River basin of Xinjiang, northwestern China, this paper summarizes synthetically the climate change and associated responses of water resources in the mountainous area, land use and land cover in the oasis, and plants responding to environmental stresses in the desert area of the river basin. Research gaps, challenges, and future perspectives in the eco-hydrological studies of the Tarim River basin are also discussed. PMID:22392285

  7. Progress, challenges and prospects of eco-hydrological studies in the Tarim river basin of Xinjiang, China.

    PubMed

    Chen, Yaning; Xu, Changchun; Chen, Yapeng; Liu, Yongbo; Li, Weihong

    2013-01-01

    Eco-hydrological research in arid inland river basins has been a focus of geologists and ecologists as it is crucial for maintaining the sustainable development of socio-economy, particularly in ecologically vulnerable areas. Based on the research work carried out in the Tarim River basin of Xinjiang, northwestern China, this paper summarizes synthetically the climate change and associated responses of water resources in the mountainous area, land use and land cover in the oasis, and plants responding to environmental stresses in the desert area of the river basin. Research gaps, challenges, and future perspectives in the eco-hydrological studies of the Tarim River basin are also discussed.

  8. Christmas Mountains

    Atmospheric Science Data Center

    2013-04-17

    article title:  Christmas Mountains     View Larger ... of New Brunswick. Located above image center are the Christmas Mountains, a region of old-growth forest nestled in a remote ... date:  Mar 8, 2001 Images:  Christmas Mountains location:  Canada ...

  9. Climatic Limits on Landscape Development in the Northwestern Himalaya

    PubMed

    Brozović; Burbank; Meigs

    1997-04-25

    The interaction between tectonism and erosion produces rugged landscapes in actively deforming regions. In the northwestern Himalaya, the form of the landscape was found to be largely independent of exhumation rates, but regional trends in mean and modal elevations, hypsometry (frequency distribution of altitude), and slope distributions were correlated with the extent of glaciation. These observations imply that in mountain belts that intersect the snowline, glacial and periglacial processes place an upper limit on altitude, relief, and the development of topography irrespective of the rate of tectonic processes operating.

  10. Application of Time Series Insar Technique for Deformation Monitoring of Large-Scale Landslides in Mountainous Areas of Western China

    NASA Astrophysics Data System (ADS)

    Qu, T.; Lu, P.; Liu, C.; Wan, H.

    2016-06-01

    Western China is very susceptible to landslide hazards. As a result, landslide detection and early warning are of great importance. This work employs the SBAS (Small Baseline Subset) InSAR Technique for detection and monitoring of large-scale landslides that occurred in Li County, Sichuan Province, Western China. The time series INSAR is performed using descending scenes acquired from TerraSAR-X StripMap mode since 2014 to get the spatial distribution of surface displacements of this giant landslide. The time series results identify the distinct deformation zone on the landslide body with a rate of up to 150mm/yr. The deformation acquired by SBAS technique is validated by inclinometers from diverse boreholes of in-situ monitoring. The integration of InSAR time series displacements and ground-based monitoring data helps to provide reliable data support for the forecasting and monitoring of largescale landslide.

  11. Influences of pH and CO2 on the formation of Metasilicate mineral water in Changbai Mountain, Northeast China

    NASA Astrophysics Data System (ADS)

    Yan, Baizhong; Xiao, Changlai; Liang, Xiujuan; Wu, Shili

    2015-07-01

    Mineral dissolution reactions actively participate in controlling the composition of mineral water. In this study, water soluble, acidic-alkaline and carbonated solution experiments were designed, and mineral reaction mechanisms were researched using chemical kinetics and the minimum free-energy method. The results showed that the release of metasilicate was controlled by pH, CO2, and rock characteristics. In the water soluble experiment, the release process of metasilicate in powdered rocks reached equilibrium after 40 days, while metasilicate in solid rocks took 170 days. The release process of metasilicate in solid rocks satisfied an asymptotic model, while in powdered rocks it accorded with the Stanford reaction kinetic model. In the acidic-alkaline experiment, metasilicate was released earlier under acidic conditions (2.46 < pH < 7) than under alkaline conditions (7 < pH < 10.61). The release process of metasilicate under acidic conditions reached equilibrium in 40 days, compared with 60 days for alkaline conditions. The addition of CO2 to the water solution was beneficial to the formation of metasilicate. Under neutral pH conditions, the reaction barely occurred. Under alkaline conditions, metasilicate was produced by the hydrolysis of metasilicate minerals. Under acidic and additional CO2 conditions, metasilicate formation was mainly via the reaction of H+, CO2, and metasilicate minerals. From these results, we concluded that the metasilicate mineral water from the Changbai Mountains, Jingyu County, is generated by a combination of the hydrolysis of metasilicate minerals and the reaction of H+, CO2, and metasilicate minerals. These results can contribute to a better development and protection of the mineral water resources in the Changbai Mountains.

  12. Physicochemical impacts of dust particles on alpine glacier meltwater at the Laohugou Glacier basin in western Qilian Mountains, China.

    PubMed

    Dong, Zhiwen; Qin, Dahe; Chen, Jizu; Qin, Xiang; Ren, Jiawen; Cui, Xiaoqing; Du, Zhiheng; Kang, Shichang

    2014-09-15

    This work discusses the temporal variation of various physicochemical species in the meltwater runoff of Laohugou Glacier No. 12 (4260 ma.s.l.) in central Asia, and their correlation with dust particles, based on a two-year field observation in summer 2012 and 2013, mainly focusing on dust concentration and size distribution, meltwater chemistry, particles SEM-EDX analysis in the meltwater, and MODIS atmospheric optical depth fields around the Qilian Mountains in central Asia. We find that, the volume-size distribution of dust particles in the meltwater is mainly composed of three parts, which includes fine aerosol particles (with diameter of 0~3.0 μm, mainly PM 2.5), atmospheric dust (with diameter of 3.0~20 μm), and local dust particles (20~100 μm), respectively. Comparison of dust particles in the snowpack and meltwater runoff indicates that, large part of dust particles in the meltwater may have originated from atmospheric dust deposition to the snow and ice on the glacier, and transported into the meltwater runoff. Moreover, temporal variation of dust and major ions (especially crustal species) is very similar with each other, showing great influence of dust particles to the chemical constituents of the glacier meltwater. SPM and TDS implied significant influences of dust to the physical characteristics of the glacier meltwater. Results showed that, accelerated glacier melting may affect physicochemical characteristics of the meltwater at an alpine basin under global warming. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm, showed great influence of regional dust transportation over western Qilian Mountains in springtime. SEM-EDX analysis shows that dust particles in the glacier meltwater contain Si-, Al-, Ca-, K-, and Fe-rich materials, such as quartz, albite, aluminate, and fly ash, similar to that deposited in snowpack. These results showed great and even currently underestimated influences of atmospheric dust

  13. [Difference between carbon storage of burned area under different restorations in Greater Xing' an Mountains, Northeast China].

    PubMed

    Xin, Ying; Zou, Meng-ling; Zhao, Yu-sen

    2015-11-01

    In order to explore forest restoration approach effect on carbon storage of severely burned area in Greater Xing'an Mountains, the carbon contents of tree, shrub, herb and litter from two plantations (Larix gmelinii and Pinus sylvestris var. mongolica) and natural secondary forest were determined, respectively, by using dry combustion method. The biomass of each component was obtained to estimate the distribution characterization of forest vegetation carbon storage by combing whole harvest method with average standard wood method. The results showed that, for both plantations and secondary forest, the average carbon content of shrub was higher than that of arbor and herb. In the L. gmelinii plantation, the average carbon contents of shrub, litter, arbor and herb were 45.8%, 45.3%, 44.4% and 33.6%, respectively. The average carbon content of shrub and arbor was more than 50% in P. sylvestris var. mongolica plantation, while that of arbor, shrub and litter was about 42% for the secondary forest. The biomass of arbor was higher than shrub and herb. In L. gmelinii plantation, the total biomass of vegetation and litter was 123.90 t · hm(-2), which was significantly higher than that of P. sylvestris var. mongolica plantation and secondary forest. The carbon storage of vegetation in L. gmelinii plantation was 50.97 t · hm(-2), among which the arbor was 49.87 t · hm(-2), accounting for 97.8% of the total carbon storage in forest vegetation, while the proportion of herb carbon storage only occupied 0.02%. The total carbon storage of plantations was higher than that of the secondary forest, suggesting a stronger capacity of carbon sink through artificial restoration on severely burned area in Greater Xing' an Mountains during this period.

  14. Changing stakeholder relationships in nature reserve management: a case study on Snake Island-Laotie Mountain National Nature Reserve, Liaoning, China.

    PubMed

    Zhou, Dan; Wang, Ziyan; Lassoie, James; Wang, Xiaoping; Sun, Lixin

    2014-12-15

    The number and total area of nature reserves in China has increased rapidly over the past couple of decades; however, the ability to effectively manage these reserves has not kept pace and conflicts between conservation efforts and economic development have emerged. The Snake Island-Laotie Mountain National Nature Reserve (SILMNNR) currently is experiencing the challenges of balancing conservation with local community development. This paper uses components analysis of human ecosystems (HEC) to examine conflicts arising from the management of the nature reserve and uses a stakeholder analysis to identify and better understand stakeholder inter-relationships in the SILMNNR-HEC. The goal of this study is to identify critical factors influencing stakeholder relationships in order to find ways of relieving conflicts between the reserve management and development. The stakeholder analysis revealed that the key stakeholders in the SILMNNR-HEC are natural resources, the Liaoning SILMNNR Authority, local residents, and enterprise developers; however, there was unequal power among stakeholders in the decision making process affecting the nature reserve. The paper evaluated the conditions and processes of SILMNNR-HEC through a framework of stakeholder relationships where critical factors, such as policy, finance, technology, and labor, and their respective strengths and feedbacks among stakeholders, were assessed and showed unequal flows of power among stakeholders. Two approaches are provided for transforming the unbalanced relationships into a stable and sustainable framework to sustainably manage the nature reserve: the first is by changing stakeholder relationships from opposition to cooperation; and the second by enhancing feedbacks and dynamics among stakeholders. The analysis used in this paper can be used as a model to assess conflicts around other protected areas in China and elsewhere. PMID:25190597

  15. Nitrate pollution and its transfer in surface water and groundwater in irrigated areas: a case study of the Piedmont of South Taihang Mountains, China.

    PubMed

    Li, Jing; Li, Fadong; Liu, Qiang; Suzuki, Yoshimi

    2014-12-01

    Irrigation projects have diverted water from the lower reaches of the Yellow River in China for more than 50 years and are unique in the world. This study investigated the effect of irrigation practices on the transfer and regional migration mechanisms of nitrate (NO3(-)) in surface water and groundwater in a Yellow River alluvial fan. Hydrochemical indices (EC, pH, Na(+), K(+), Mg(2+), Ca(2+), Cl(-), SO4(2-), and HCO(3-)) and stable isotopic composition (δ18O and δD) were determined for samples. Correlation analysis and principal component analysis (PCA) were performed to identify the sources of water constituents. Kriging was employed to simulate the spatial diffusion of NO3(-) and stable isotopes. Our results demonstrated that the groundwater exhibited more complex saline conditions than the surface water, likely resulting from alkaline conditions and lixiviation. NO3(-) was detected in all samples, 87.0% of which were influenced by anthropogenic activity. The NO3(-) pollution in groundwater was more serious than the common groundwater irrigation areas in the North China Plain (NCP), and was also slightly higher than that in surface water in the study area, but this was not statistically significant (p > 0.05). In addition, the groundwater sites with higher NO3(-) concentrations did not overlap with the spatial distribu