[Life cycle of the taiga tick ixodes persulcatus in taiga forests of the eastern Sayan Plateau].

PubMed

Korotkov, Iu S

2014-01-01

The Ixodes persulcatus life cycle has been studied in natural environments of taiga fo- rests in The Eastern Sayan Plateau (56 10' N, 91 30' E). Engorged larvae and nymphs de- velop with a morphogenetic diapause or without diapause, with ratio of these two ways of development for larvae and nymphs 77.25/22.75% and 43.43/56.57%, respectively. The hypothetic season hemipopulation consists of 34.5 +/- 4.5, 50.1 +/- 1.3, 13.2 +/- 4.0 n 2.2% of unfed imagoes, completing 3-year, 4-year, 5-year, and 6-year life cycles, respectively. Mean life span is 3.83 +/- 0.10 years per generation. The "life table" predicting the probability to complete life cycle through phases from egg to adult, was developed.

Underestimation of the Tambora effects in North American taiga ecosystems

NASA Astrophysics Data System (ADS)

Gennaretti, Fabio; Boucher, Etienne; Nicault, Antoine; Gea-Izquierdo, Guillermo; Arseneault, Dominique; Berninger, Frank; Savard, Martine M.; Bégin, Christian; Guiot, Joel

2018-03-01

The Tambora eruption (1815 AD) was one of the major eruptions of the last two millennia and has no equivalents over the last two centuries. Here, we collected an extensive network of early meteorological time series, climate simulation data and numerous, well-replicated proxy records from Eastern Canada to analyze the strength and the persistence of the Tambora impact on the regional climate and forest processes. Our results show that the Tambora impacts on the terrestrial biosphere were stronger than previously thought, and not only affected tree growth and carbon uptake for a longer period than registered in the regional climate, but also determined forest demography and structure. Increased tree mortality, four times higher than the background level, indicates that the Tambora climatic impact propagated to influence the structure of the North American taiga for several decades. We also show that the Tambora signal is more persistent in observed data (temperature, river ice dynamics, forest growth, tree mortality) than in simulated ones (climate and forest-growth simulations), indicating that our understanding of the mechanisms amplifying volcanic perturbations on climates and ecosystems is still limited, notably in the North American taiga.

[Abundance of larvae and nymphs of the taiga tick Ixodes persuicatus (Acari: Ixodidae) on small mammals in the cut-over lands of the middle taiga subzone of Karelia].

PubMed

Bugmyrin, S V; Bespiatova, L A; Anikanova, V S; Ieshko, E P

2009-01-01

Data of long-term investigations (1998-2004) on the abundance of the taiga tick larvae and nymphs in the cut-over lands of different age in the middle taiga subzone of Karelia (62 degrees 04'S; 33 degrees 55'W) are presented. The investigation was carried out on three model cut-over lands of different age: 1) "young" cut-over land; age of cut-over in the beginning of investigation is 7 years; Betula-Deschampsia cespitosa-Agrostis tenuis; 2) "middle" cut-over land; age of cut-over is 12 years; Salix-Deschampsia cespitosa-Agrostis tenuis; 3) "old" cut-over land; age of cut-over 25 years; Alnus incana-Rubus idaeus-grass. The number of ticks was estimated by using common parasitological indices: prevalence, abundance, and index of feeding intensity (the tick abundance multiply by the number of small mammals per hundred traps-nights). In the beginning of investigation the "young" cut-over land was a typical meadow association. The lowest tick abundance was recorded here. That was a result of unfavorable abiotic conditions and low number of small mammals in the beginning of summer. "Middle" cut-over land is characterized by the highest number of the tick larvae, which is the evidence for high number of the hosts of tick imago. "Old" cut-over land has the optimum conditions for development of taiga ticks. High abundance of the ticks (larvae and nymphs) was recorded during the whole period of investigations. The number of preimaginal ticks is shown to be much higher in cut-over lands as compared with that in mixed and coniferous forests, due to the higher number of small mammals.

The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

PubMed

Wang, Xin; Cao, Lei; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

2018-01-01

The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle.

The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

PubMed Central

Wang, Xin; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

2018-01-01

The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle. PMID:29479493

High resolution wetland mapping in West Siberian taiga zone for methane emission inventory

NASA Astrophysics Data System (ADS)

Terentieva, I. E.; Glagolev, M. V.; Lapshina, E. D.; Sabrekov, A. F.; Maksyutov, S. S.

2015-12-01

High latitude wetlands are important for understanding climate change risks because these environments sink carbon and emit methane. Fine scale heterogeneity of wetland landscapes pose challenges for producing the greenhouse gas flux inventories based on point observations. To reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the taiga zone of West Siberia on a scene-by-scene basis using a supervised classification of Landsat imagery. The training dataset was based on high-resolution images and field data that were collected at 28 test areas. Classification scheme was aimed at methane inventory applications and included 7 wetland ecosystem types composing 9 wetland complexes in different proportions. Accuracy assessment based on 1082 validation polygons of 10 × 10 pixels indicated an overall map accuracy of 79 %. The total area of the wetlands and water bodies was estimated to be 52.4 Mha or 4-12 % of the global wetland area. Ridge-hollow complexes prevail in WS's taiga, occupying 33 % of the domain, followed by forested bogs or "ryams" (23 %), ridge-hollow-lake complexes (16 %), open fens (8 %), palsa complexes (7 %), open bogs (5 %), patterned fens (4 %), and swamps (4 %). Various oligotrophic environments are dominant among the wetland ecosystems, while fens cover only 14 % of the area. Because of the significant update in the wetland ecosystem coverage, a considerable revaluation of the total CH4 emissions from the entire region is expected. A new Landsat-based map of WS's taiga wetlands provides a benchmark for validation of coarse-resolution global land cover products and wetland datasets in high latitudes.

Unconsidered sporadic sources of carbon dioxide emission from soils in taiga forests.

PubMed

Karelin, D V; Zamolodchikov, D G; Isaev, A S

2017-07-01

Long-term monitoring in the Russian taiga zone has shown that all known extreme destructive effects resulting in the weakening and death of tree stands (windfalls, pest attacks, drought events, etc.) can be sporadic, but significant sources of CO 2 soil emission. Among them are (i) a recently found effect of the multiyear CO 2 emission from soil at the bottom of deadwood of spruce trees that died due to climate warming and subsequent pest outbreaks, (ii) increased soil CO 2 emissions due to to the fall of tree trunks during massive windfalls, and (iii) pulse CO 2 emission as a result of the so-called Birch effect after drought events in the taiga zone. According to the modeling, while depending on the spatial and temporal scales of their manifestation, the impact of these sporadic effects on the regional and global soil respiration fluxes could be significant and should be taken into consideration. This is due to continuing Climate Change, and further increase of local, regional and Global human impacts on the atmospheric greenhouse gases balance, and land use, as well.

A latitudinal gradient in tree growth response to climate warming in the Siberian taiga

Treesearch

Andrea H. Lloyd; Andrew G. Bunn; Logan Berner

2010-01-01

We investigated the climate response of three Siberian taiga species, Larix cajanderi, Picea obovata, and Pinus sylvestris, across a latitudinal gradient in central Siberia. We hypothesized that warming is more frequently associated with increased growth for evergreen conifers (P. obovata and P....

[Testate amoebae inhabiting middle taiga bogs in Western Siberia].

PubMed

Kur'ina, I V; Preĭs, Iu I; Bobrov, A A

2010-01-01

The population of testate amoebae from the most typical middle taiga bogs of Western Siberia have been studied. More than one hundred (103) species and intraspecific taxons of testate amoebae have been revealed in recent surface samples. The relation between ecological characteristics of habitats and the composition of a Protozoa population has been demonstrated. The ecological preferences of species concerning the index of wetness, ash level, and acidity have been revealed. Using the correspondence analysis, the ecological optimums and the tolerance of species and intraspecific taxons of testate amoebae have been established.

[Exoskeleton anomalies among taiga tick males from populations of the Asiatic part of Russia].

PubMed

Nikitin, A Ya; Morozov, I M

2017-01-01

The taiga tick (Icodes persulcatus, Schulze, 1930) is the main and most epidemiologically dangerous vector of tick-born encephalitis virus (TBEV) and Borrelia in most parts of Russia's territory (Alekseev et al., 2008). The purpose of this article is to describe the incidence rate of I. persulcatus males with exoskeleton anomalies in populations of the Asiatic part of Russia. A total of 2630 taiga tick males were morphologically analyzed. They were collected in Far Eastern, Siberian and Ural Federal Districts (respectively, FEFD, SFD, UFD) in 15 geographically remote locations. It is shown that in all populations there are adult ticks with impaired exoskeleton, among which two types dominate: twin dents at the back of conscutum (P11), and uneven surface of conscutum - a "shagreen skin" (P9). The frequency of abnormalities in males from the areas with temperate monsoon and temperate continental climate (FEFD) was definitely lower (6.5 ± 1.05 %), than in individuals from the territories of SFD (29.7 ± 1.03 %) and UFD (25.8 ± 3.93 %) with continental and sharply continental climate. FEFD territory is also characterized by a less number of males having two simultaneous exoskeleton anomalies. Similar district-preconditioned differences in the frequency of recorded body distortions are also typical of females, with a higher percentage of deviant individuals in comparison with males. Thus, the identified polymorphism of exoskeleton structure of the taiga tick may reflect the natural phenogeographical variability of this trait and might not be the result of human impact.

A Subpixel Classification of Multispectral Satellite Imagery for Interpetation of Tundra-Taiga Ecotone Vegetation (Case Study on Tuliok River Valley, Khibiny, Russia)

NASA Astrophysics Data System (ADS)

Mikheeva, A. I.; Tutubalina, O. V.; Zimin, M. V.; Golubeva, E. I.

2017-12-01

The tundra-taiga ecotone plays significant role in northern ecosystems. Due to global climatic changes, the vegetation of the ecotone is the key object of many remote-sensing studies. The interpretation of vegetation and nonvegetation objects of the tundra-taiga ecotone on satellite imageries of a moderate resolution is complicated by the difficulty of extracting these objects from the spectral and spatial mixtures within a pixel. This article describes a method for the subpixel classification of Terra ASTER satellite image for vegetation mapping of the tundra-taiga ecotone in the Tuliok River, Khibiny Mountains, Russia. It was demonstrated that this method allows to determine the position of the boundaries of ecotone objects and their abundance on the basis of quantitative criteria, which provides a more accurate characteristic of ecotone vegetation when compared to the per-pixel approach of automatic imagery interpretation.

Refined δ13C trend of the Dal'nyaya Taiga series of the Ura uplift (Vendian, southern part of Middle Siberia)

NASA Astrophysics Data System (ADS)

Rud'ko, S. V.; Petrov, P. Yu.; Kuznetsov, A. B.; Shatsillo, A. V.; Petrov, O. L.

2017-12-01

New data were obtained on δ13Ccarb and δ18O variations in the sequence of deposits of the Dal'nyaya Taiga series at the western and eastern flanks of the Ura anticline. The summary δ13C curve was plotted in view of the correlation of sequence-stratigraphic data of the basin analysis. A series of positive anomalies was found within the succession. Alternatives for global chemostratigraphic correlation of the Dal'nyaya Taiga series of the Ura uplift were considered.

Water-soluble low-molecular-weight organic acids in automorphic loamy soils of the tundra and taiga zones

NASA Astrophysics Data System (ADS)

Shamrikova, E. V.; Gruzdev, I. V.; Punegov, V. V.; Khabibullina, F. M.; Kubik, O. S.

2013-06-01

The formation features of water-soluble low-molecular-weight organic acids (LMWOAs) in a zonal series of automorphic soils on loose silicate rocks from the middle taiga to the southern tundra (typical podzolic, gley-podzolic, and surface-gley tundra soils) were first revealed by gas chromatography mass spectrometry and gas-liquid chromatography. The content of LMWOAs varies within the range of 1-14 mg/dm3, which corresponds to 1-5% of the total carbon of the water-soluble soil organic matter. It has been shown that a subzonal feature of gley-podzolic soils in the northern taiga is the high content of LMWOAs, including primarily the strongest aliphatic hydroxyl acids. Possible mechanisms of their formation and accumulation in soils have been considered.

Summer foods of lesser scaup in subarctic taiga

USGS Publications Warehouse

Bartonek, J.C.; Murdy, H.W.

1970-01-01

Twenty-five adult and 38 juvenile lesser scaup (Aythya affinis) that were collected in taiga north of Great Slave Lake, Northwest Territories, had eaten almost entirely animal material (99 i?? 1 per cent, P < 0.05). Juveniles collected in mid-summer had tended to feed on free-swimming organisms such as Chaoborinae and Conchostraca; whereas juveniles collected in late summer had tended to feed, as did adults in June, on bottom-associated organisms such as amphipods, odonates, and corixids. Sampling aquatic organisms concomitantly with collecting ducks revealed that seeds, copepods, and cladocerans were seldom or never eaten; most other organisms were consumed in proportions that were not significantly different (P < 0.05) from those in the collected samples.

Snow distribution and heat flow in the taiga

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

Sturm, M.

1992-05-01

The trees of the taiga intercept falling snow and cause it to become distributed in an uneven fashion. Around aspen and birch, cone-shaped accumulations form. Beneath large spruce trees, the snow cover is depleted, forming a bowl-shaped depression called a tree well. Small spruce trees become covered with snow, creating cavities that funnel cold air to the snow/ground interface. The depletion of snow under large spruce trees results in greater heat loss from the ground. A finite difference model suggests that heat flow from tree wells can be more than twice that of undisturbed snow. In forested watersheds, this increasemore » can be a significant percentage of the total winter energy exchange.« less

Mapping of West Siberian taiga wetland complexes using Landsat imagery: implications for methane emissions

NASA Astrophysics Data System (ADS)

Evgenievna Terentieva, Irina; Vladimirovich Glagolev, Mikhail; Dmitrievna Lapshina, Elena; Faritovich Sabrekov, Alexandr; Maksyutov, Shamil

2016-08-01

High-latitude wetlands are important for understanding climate change risks because these environments sink carbon dioxide and emit methane. However, fine-scale heterogeneity of wetland landscapes poses a serious challenge when generating regional-scale estimates of greenhouse gas fluxes from point observations. In order to reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the taiga zone of The West Siberia Lowland (WSL) on a scene-by-scene basis using a supervised classification of Landsat imagery. Training data consist of high-resolution images and extensive field data collected at 28 test areas. The classification scheme aims at supporting methane inventory applications and includes seven wetland ecosystem types comprising nine wetland complexes distinguishable at the Landsat resolution. To merge typologies, mean relative areas of wetland ecosystems within each wetland complex type were estimated using high-resolution images. Accuracy assessment based on 1082 validation polygons of 10 × 10 pixel size indicated an overall map accuracy of 79 %. The total area of the WSL wetlands and water bodies was estimated to be 52.4 Mha or 4-12 % of the global wetland area. Ridge-hollow complexes prevail in WSL's taiga zone accounting for 33 % of the total wetland area, followed by pine bogs or "ryams" (23 %), ridge-hollow-lake complexes (16 %), open fens (8 %), palsa complexes (7 %), open bogs (5 %), patterned fens (4 %), and swamps (4 %). Various oligotrophic environments are dominant among wetland ecosystems, while poor fens cover only 14 % of the area. Because of the significant change in the wetland ecosystem coverage in comparison to previous studies, a considerable reevaluation of the total CH4 emissions from the entire region is expected. A new Landsat-based map of WSL's taiga wetlands provides a benchmark for validation of coarse-resolution global land cover products and wetland data sets in high latitudes.

Comparative Analysis of the Number and Structure of the Complexes of Microscopic Fungi in Tundra and Taiga Soils in the North of the Kola Peninsula

NASA Astrophysics Data System (ADS)

Korneikova, M. V.

2018-01-01

The number, biomass, length of fungal mycelium, and species diversity of microscopic fungi have been studied in soils of the tundra and taiga zones in the northern part of the Kola Peninsula: Al-Fe-humus podzols (Albic Podzols), podburs (Entic Podzols), dry peaty soils (Folic Histosols), low-moor peat soils (Sapric Histosols), and soils of frost bare spots (Cryosols). The number of cultivated microscopic fungi in tundra soils varied from 8 to 328 thousand CFU/g, their biomass averaged 1.81 ± 0.19 mg/g, and the length of fungal mycelium averaged 245 ± 25 m/g. The number of micromycetes in taiga soils varied from 80 to 350 thousand CFU/g, the number of fungal propagules in some years reached 600 thousand CFU/g; the fungal biomass varied from 0.23 to 6.2 mg/g, and the length of fungal mycelium varied from 32 to 3900 m/g. Overall, 36 species of fungi belonging to 16 genera, 13 families, and 8 orders were isolated from tundra soils. The species diversity of microscopic fungi in taiga soils was significantly higher: 87 species belonging to 31 genera, 21 families, and 11 orders. Fungi from the Penicillium genus predominated in both natural zones and constituted 38-50% of the total number of isolated species. The soils of tundra and taiga zones were characterized by their own complexes of micromycetes; the similarity of their species composition was about 40%. In soils of the tundra zone, Mortierella longicollis, Penicillium melinii, P. raistrickii, and P. simplicissimum predominated; dominant fungal species in soils of the taiga zone were represented by M. longicollis, P. decumbens, P. implicatum, and Umbelopsis isabellina.

Evaluating the effects of fire and landscape characteristics on the export of carbon, nutrients and ions from watersheds of the Taiga Plains and Taiga Shield ecoregions of the NWT

NASA Astrophysics Data System (ADS)

Mengistu, S. G.; Tank, S. E.; Olefeldt, D.; Spence, C.; Quinton, W. L.; Dion, N.

2016-12-01

Fire is a natural process that can significantly modify landscapes and ecosystems. In permafrost-affected terrains, fire-induced changes to soils and active layer depths can have important implications for hydrological flow paths and the chemistry of runoff water, and therefore also the health and functioning of recipient aquatic ecosystems. Although the effects of fire on water chemistry have been relatively well studied in non-permafrost affected landscapes, less attention has been given to how fire affects northern aquatic ecosystems, particularly those of the Northwest Territories (NWT), despite an increasing frequency of fire in this region. To address this gap, we make use of a recent large-scale burn that occurred across the discontinuous permafrost landscape of the southern NWT, to explore how fire and variations in landscape characteristics affect water chemistry in this area. The study collected water chemistry samples during the summers of 2015 and 2016 from paired watersheds in the Taiga Shield (Boundary Creek / Baker Creek) and Taiga Plains (Spence Creek / Scotty Creek) ecoregions, in addition to a synoptic survey that measured discharge and water chemistry across a series of 50 watersheds in these two regions. We specifically targeted the Taiga Shield and Plains since differences in soil characteristics between these two regions were expected to lead to differences in how recipient aquatic systems respond to fire. Preliminary results from the paired catchment work show a clear spike in the chemistry of fire-affected watersheds early in the ice-free season, followed by a period when stream water chemistry in burned watersheds declines to a level that is similar to that in the unburned analogs. While average electrical conductivity, Ca, Na, and Hg concentrations were highest in the Plains watersheds, constituents including average TN, TP, Al, DOC, Fe, K, Mg, and Cl appeared to be the highest for the fire-affected Shield watershed. Preliminary results

[POLYMORPHISM IN THE PHENOTYPIC STRUCTURE OF A POPULATION OF TAIGA TICK AND ITS EPIDEMIOLOGICAL SIGNIFICANCE].

PubMed

Morozov, I M; Alekseev, A N; Dubinina, E V; Nikitin, A Ya; Melnikova, O V; Andaev, E I

2015-01-01

The paper presents the results of 10-year (2005-2014) observations of an Ixodespersulcatus Schulze population. The purpose of this investigation was to trace long-term changes in the structure of the taiga tick population from the proportion of specimens with external skeletal anomalies and to assess a relationship between the pattern of imago phenotypic variation and the virus percentage of a carrier. There were a total of reports of the external skeletal structure of 1123 females gathered from plants to a flag in an area at 43 km from the Baikal Road connecting Irkutsk and the settlement of Listvyanka (Irkutsk Region). The proportion of specimens with anomalies averaged 37.8 +/- 1.88%. Four-to-seven varying anomalies were annually recorded. There was a preponderance of scutum impairment (an average of 17.0 +/- 3.08% of all females) that was a conglomerate of prominences and indentations along the entire clypeus surface and that was denoted P9. The nature of a change in the proportion of ticks with two anomalies (average monthly registration rate, 2.5 +/- 0.66%) is exhibited by three-year high-frequency oscillations whereas the specimens with P9 anomalies fail to show so clear cycling. The percentage of virus-containing taiga ticks was individually determined estimating the level of tick-borne encephalitis virus antigen by an enzyme immunoassay. A total of 4022 ticks were examined. The male and female data were pooled. There was a positive correlation between the change in the proportion of females with P9 anomaly and the infection of ticks in the examined population (Spearman's correlation coefficient, 0.88; P < 0.01). This supports the earlier observation of the greater epidemiological significance of the imago of a taiga tick with external skeletal anomalies particularly with considerably marked ones.

[Etiological structure of complex Ixodes tickborne borreliosis natural foci of southern taiga].

PubMed

Korenberg, É I; Nefedova, V V; Gorelova, N B; Kovalevskiĭ, Iu V; Fadeeva, I A; Golubova, D A

2011-01-01

89 primary isolates of B. garinii and 72 B. afzelii from different developmental phases of I. persulcatus, I. trianguliceps and form small mammalian hosts of Borrelia were obtained at an area of ca. 30 km2 located in low-mountain southern taiga forests (Perm region). The area provides home for two Borrelia species (B. garinii and B. afzeli) and their natural carrier Ixodes persulcatus. 23 isolate of B.garnii were obtained from skin biopsies and blood samples taken in patients with borreliosis. The isolates were studied by sequencing rrf(5S)-rrr(23S) spacer. The term genetic variant (genovariant) is proposed for the totality of isolates belonging to a given genetic subgroup of the concrete genospecies and having a similar nucleotide sequence of rrf(5S)-rrr(23S) spacer or other conservative genomic sequence. Genovariant is ths smallest intraspecies taxonomic unit in widespread Borrelia pathogenic for man. Several genovariants of B. garinii and B. afzelii may simultaneously occur in combined parasitic systems formed by these spirochetal agents of Ixodes tick-borne borreliosis. Such natural foci in southern taiga of the Perm region have a complicated etiological structure due to the presence of 14 genovariants of Borrelia belonging to the two above genetic subgroups. Specific genovariants occur annually but with different frequency. They are lacking in host-specificity.

[EFFECT OF PYRETHROIDS ON TAIGA TICKS (IXODES PERSULCATUS IXODIDAE)].

PubMed

Germant, O M; Shashina, N I

2016-01-01

Nonspecific prevention of infections, the agents of which are transmitted by Ixodes ticks, is aimed at stopping the suction of the ticks to humans and is substantially based one the use of acaricides. The most interesting group of compounds to be used to individually protect humans is pyrethroids that cause different nerve conduction disturbances in the ticks, which result in their paralysis and death more significantly rapidly than the compounds from other chemical groups. The effect of 8 pyrethroids was investigated when the taiga ticks were in contact with the tissue treated with the compounds. The relationship of the chemical structure of pyrethroids with their acaricidal activity was analyzed from motor activity values and knockdown time. The test pyreithroids, in order of decreasing acaricidal activity, are imiprothrin cyphenothrin, cyfluthrin, alpha-cyperamethrin, zeta-cyperimethrin fenothrin, flumethrin.

Response of middle-taiga permafrost landscapes of Central Siberia to global warming in the late 20th and early 21st centuries

NASA Astrophysics Data System (ADS)

Medvedkov, Alexey A.

2016-11-01

In this paper, regional features of a climatogenic response of the middle-taiga permafrost landscapes of Central Siberia, as well as corresponding transformations of the exodynamic processes, are considered. Lithological-geomorphologic and landscape- geocryological data are analyzed with large amounts of actual data and results of monitoring surveys. Specific features of an ecotone localization of middle-taiga permafrost landscapes and their typical physiognomic characteristics are described. A comprehensive investigation of representative key sites makes it possible to discover the response of different types of permafrost landscapes to regional climate warming. A rapid increase in the active layer depth, slower creep, transformations of the moving kurums, intensive solifluction, and a local replacement of solifluction by landslides-earthflows are revealed within ecotone landscapes of the cryolithozone.

Development of an adaptive harvest management program for Taiga bean geese

USGS Publications Warehouse

Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper

2016-01-01

This report describes recent progress in specifying the elements of an adaptive harvest program for taiga bean goose. It describes harvest levels appropriate for first rebuilding the population of the Central Management Unit and then maintaining it near the goal specified in the AEWA International Single Species Action Plan (ISSAP). This report also provides estimates of the length of time it would take under ideal conditions (no density dependence and no harvest) to rebuild depleted populations in the Western and Eastern Management Units. We emphasize that our estimates are a first approximation because detailed demographic information is lacking for taiga bean geese. Using allometric relationships, we estimated parameters of a thetalogistic matrix population model. The mean intrinsic rate of growth was estimated as r = 0.150 (90% credible interval: 0.120 – 0.182). We estimated the mean form of density dependence as   2.361 (90% credible interval: 0.473 – 11.778), suggesting the strongest density dependence occurs when the population is near its carrying capacity. Based on expert opinion, carrying capacity (i.e., population size expected in the absence of hunting) for the Central Management Unit was estimated as K  87,900 (90% credible interval: 82,000 – 94,100). The ISSAP specifies a population goal for the Central Management Unit of 60,000 – 80,000 individuals in winter; thus, we specified a preliminary objective function as one which would minimize the difference between this goal and population size. Using the concept of stochastic dominance to explicitly account for uncertainty in demography, we determined that optimal harvest rates for 5, 10, 15, and 20-year time horizons were h = 0.00, 0.02, 0.05, and 0.06, respectively. These optima represent a tradeoff between the harvest rate and the time required to achieve and maintain a population size within desired bounds. We recognize, however, that regulation of absolute harvest rather than

Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia.

PubMed

Kalinina, Olga; Goryachkin, Sergey V; Karavaeva, Nina A; Lyuri, Dmitriy I; Giani, Luise

2010-04-26

Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization. A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition. The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration.

Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica

PubMed Central

Dulamsuren, Choimaa; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

2010-01-01

Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia’s forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140–490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century. PMID:20571829

Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia

PubMed Central

2010-01-01

Background Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization. Results A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition. Conclusion The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration. PMID:20420668

Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica.

PubMed

Dulamsuren, Choimaa; Hauck, Markus; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

2010-08-01

Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia's forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140-490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century.

Trees as methane sources: A case study of West Siberian South taiga

NASA Astrophysics Data System (ADS)

Churkina, A. I.; Mochenov, S. Yu; Sabrekov, S. F.; Glagolev, M. V.; Il’yasov, D. V.; Terentieva, I. E.; Maksyutov, S. S.

2018-03-01

Within this study, we were measuring methane emission from the tree trunks, leaves and branches in the seasonally flooded forest and in the forested bogs (pine-shrub-sphagnum ecosystems or “ryams”) in south taiga zone of Western Siberia. Our results suggest that the tree trunks may act as a methane conductor from the soil to the atmosphere bypassing the methanotrophically active zones of soil. The tree methane flux depends on a trunk diameter and an ecosystem type. The average methane emission from tree trunks was 0.0061±0.0003 mg CH4·m-2·h-1 per unit of ground area. The methane emission from branches and leaves was zero.

Artificial and natural radionuclides in soils of the southern and middle taiga zones of Komi Republic

NASA Astrophysics Data System (ADS)

Beznosikov, V. A.; Lodygin, E. D.; Shuktomova, I. I.

2017-07-01

Specific activities of artificial (137Cs, 90Sr) and natural (40K, 232Th, 226Ra) radionuclides in background soils of southern and middle taiga of Komi Republic have been estimated with consideration for the landscape-geochemical features of the territory. It has been shown that their accumulation and migration in soils are determined by the following factors: position in relief, texture, and organic matter content. No anomalous zones with increased contents of radionuclides in soils have been revealed.

MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone

NASA Technical Reports Server (NTRS)

Montesano, P. M.; Nelson, R.; Sun, G.; Margolis, H.; Kerber, A.; Ranson, K. J.

2009-01-01

A validation of the 2005 500m MODIS vegetation continuous fields (VCF) tree cover product in the circumpolar taiga-tundra ecotone was performed using high resolution Quickbird imagery. Assessing the VCF's performance near the northern limits of the boreal forest can help quantify the accuracy of the product within this vegetation transition area. The circumpolar region was divided into longitudinal zones and validation sites were selected in areas of varying tree cover where Quickbird imagery is available in Google Earth. Each site was linked to the corresponding VCF pixel and overlaid with a regular dot grid within the VCF pixel's boundary to estimate percent tree crown cover in the area. Percent tree crown cover was estimated using Quickbird imagery for 396 sites throughout the circumpolar region and related to the VCF's estimates of canopy cover for 2000-2005. Regression results of VCF inter-annual comparisons (2000-2005) and VCF-Quickbird image-interpreted estimates indicate that: (1) Pixel-level, inter-annual comparisons of VCF estimates of percent canopy cover were linearly related (mean R(sup 2) = 0.77) and exhibited an average root mean square error (RMSE) of 10.1 % and an average root mean square difference (RMSD) of 7.3%. (2) A comparison of image-interpreted percent tree crown cover estimates based on dot counts on Quickbird color images by two different interpreters were more variable (R(sup 2) = 0.73, RMSE = 14.8%, RMSD = 18.7%) than VCF inter-annual comparisons. (3) Across the circumpolar boreal region, 2005 VCF-Quickbird comparisons were linearly related, with an R(sup 2) = 0.57, a RMSE = 13.4% and a RMSD = 21.3%, with a tendency to over-estimate areas of low percent tree cover and anomalous VCF results in Scandinavia. The relationship of the VCF estimates and ground reference indicate to potential users that the VCF's tree cover values for individual pixels, particularly those below 20% tree cover, may not be precise enough to monitor 500m pixel

Radiological investigations at the "Taiga" nuclear explosion site, part II: man-made γ-ray emitting radionuclides in the ground and the resultant kerma rate in air.

PubMed

Ramzaev, V; Repin, V; Medvedev, A; Khramtsov, E; Timofeeva, M; Yakovlev, V

2012-07-01

Samples of soil and epigeic lichens were collected from the "Taiga" peaceful nuclear explosion site (61.30°N 56.60°E, the Perm region, Russia) in 2009 and analyzed using high resolution γ-ray spectrometry. For soil samples obtained at six different plots, two products of fission ((137)Cs and (155)Eu), five products of neutron activation ((60)Co, (94)Nb, (152)Eu, (154)Eu, (207)Bi) and (241)Am have been identified and quantified. The maximal activity concentrations of (60)Co, (137)Cs, and (241)Am for the soils samples were measured as 1650, 7100, and 6800 Bq kg(-1) (d.w.), respectively. The deposit of (137)Cs for the top 20 cm of soil on the tested plots at the "Taiga" site ranged from 30 to 1020 kBq m(-2); the maximal value greatly (by almost 3 orders of magnitude) exceeded the regional background (from global fallout) level of 1.4 kBq m(-2). (137)Cs contributes approximately 57% of the total ground inventory of the man-made γ-ray emitters for the six plots tested at the "Taiga" site. The other major radionuclides -(241)Am and (60)Co, constitute around 40%. Such radionuclides as (60)Co, (137)Cs, (241)Am, and (207)Bi have also been determined for the epigeic lichens (genera Cladonia) that colonized certain areas at the ground lip produced by the "Taiga" explosion. Maximal activity concentrations (up to 80 Bq kg(-1) for (60)Co, 580 Bq kg(-1) for (137)Cs, 200 Bq kg(-1) for (241)Am, and 5 Bq kg(-1) for (207)Bi; all are given in terms of d.w.) have been detected for the lower dead section of the organisms. The air kerma rates associated with the anthropogenic sources of gamma radiation have been calculated using the data obtained from the laboratory analysis. For the six plots tested, the kerma rates ranged from 50 to 1200 nGy h(-1); on average, 51% of the dose can be attributed to (137)Cs and 45% to (60)Co. These estimates agree reasonably well with the results of the in situ measurements made during our field survey of the "Taiga" site in August

Succession after stand replacing disturbances by fire, wind throw, and insects in the dark Taiga of Central Siberia.

PubMed

Schulze, E-D; Wirth, C; Mollicone, D; Ziegler, W

2005-11-01

The dark taiga of Siberia is a boreal vegetation dominated by Picea obovata, Abies sibirica, and Pinus sibirica during the late succession. This paper investigates the population and age structure of 18 stands representing different stages after fire, wind throw, and insect damage. To our knowledge, this is the first time that the forest dynamics of the Siberian dark taiga is described quantitatively in terms of succession, and age after disturbance, stand density, and basal area. The basis for the curve-linear age/diameter relation of trees is being analyzed. (1) After a stand-replacing fire Betula dominates (4,000 trees) for about 70 years. Although tree density of Betula decreases rapidly, basal area (BA) reached >30 m2/ha after 40 years. (2) After fire, Abies, Picea, and Pinus establish at the same time as Betula, but grow slower, continue to gain height and eventually replace Betula. Abies has the highest seedling number (about 1,000 trees/ha) and the highest mortality. Picea establishes with 100-400 trees/ha, it has less mortality, but reached the highest age (>350 years, DBH 51 cm). Picea is the most important indicator for successional age after disturbance. Pinus sibirica is an accompanying species. The widely distributed "mixed boreal forest" is a stage about 120 years after fire reaching a BA of >40 m2/ha. (3) Wind throw and insect damage occur in old conifer stands. Betula does not establish. Abies initially dominates (2,000-6,000 trees/ha), but Picea becomes dominant after 150-200 years since Abies is shorter lived. (4) Without disturbance the forest develops into a pure coniferous canopy (BA 40-50 m2/ha) with a self-regenerating density of 1,000 coniferous canopy trees/ha. There is no collapse of old-growth stands. The dark taiga may serve as an example in which a limited set to tree species may gain dominance under certain disturbance conditions without ever getting monotypic.

Comparative phylogeography and demographic history of the wood lemming (Myopus schisticolor): implications for late Quaternary history of the taiga species in Eurasia.

PubMed

Fedorov, V B; Goropashnaya, A V; Boeskorov, G G; Cook, J A

2008-01-01

The association between demographic history, genealogy and geographical distribution of mitochondrial DNA cytochrome b haplotypes was studied in the wood lemming (Myopus schisticolor), a species that is closely associated with the boreal forest of the Eurasian taiga zone from Scandinavia to the Pacific coast. Except for a major phylogeographic discontinuity (0.9% nucleotide divergence) in southeastern Siberia, only shallow regional genetic structure was detected across northern Eurasia. Genetic signs of demographic expansions imply that successive range contractions and expansions on different spatial scales represented the primary historical events that shaped geographical patterns of genetic variation. Comparison of phylogeographic structure across a taxonomically diverse array of other species that are ecologically associated with the taiga forest revealed similar patterns and identified two general aspects. First, the major south-north phylogeographic discontinuity observed in five out of six species studied in southeastern Siberia and the Far East implies vicariant separation in two different refugial areas. The limited distribution range of the southeastern lineages provides no evidence of the importance of the putative southeastern refugial area for postglacial colonization of northern Eurasia by boreal forest species. Second, the lack of phylogeographic structure associated with significant reciprocal monophyly and genetic signatures of demographic expansion in all nine boreal forest animal species studied to date across most of northern Eurasia imply contraction of each species to a single refugial area during the late Pleistocene followed by range expansion on a continental scale. Similar phylogeographic patterns observed in this taxonomically diverse set of organisms with different life histories and dispersal potentials reflect the historical dynamics of their shared environment, the taiga forest in northern Eurasia.

Agrogenic transformation of soil organic C in conditions of southern-taiga zone, European Russia

NASA Astrophysics Data System (ADS)

Yashin, Ivan; Vasenev, Ivan; Atenbekov, Ramiz

2017-04-01

The principal regional features of soil organic carbon (SOC) agrogenic transformation and water-soluble organic substances (WSOS) genesis and environmental functions have been investigated in the Podzols and Podzoluvisols of the representative natural and agro- ecosystems in the southern taiga subzone of the European part of Russia. Especial attention has been done to the role of SOC agrogenic degradation and WSOS with acidic and ligand properties in soil carbon dioxide emission. The long-term agroecological investigations run in the regional set of representative agrolandscape monitoring stations in the educational farm "Mikhailovskoye" (Podolsk district, Moscow region), Field experimental station and Forest experimental station (RTSAU campus, Moscow) and in the Central Forest biosphere reserve (Nelidovo district, Tver region). Field research methods include sorption lysimetry and radioactive tracers. The laboratory ones - chromatography and spectrophotometry. There were used activated charcoal brand "Carbolite", chemically purified quartz sand and barley plant residues (2-3 mm), totally labeled with 14C in the soil-horizontally distributed sorption columns. Obtained results became useful for quantitative assessment of the principal stages and processes in soil CO2 emission, including the water-soluble organic substances formation (3.0 g of SOC per 100 g of plant litter or 60-75 g of SOC per square meter of the organo-mineral horizon A0 per year) and CO2 emission. In the middle taiga ecosystem conditions (with relatively low soil biological activity) the highest emission of CO2 (83,0±4.1 % of the newly formed WSOS) was in case of arable Podzoluvisols, and lowest one (32,4±2,5%) - in their semihydromorphic versions.

Comparing carbon storage of Siberian tundra and taiga permafrost ecosystems at very high spatial resolution

NASA Astrophysics Data System (ADS)

Siewert, Matthias B.; Hanisch, Jessica; Weiss, Niels; Kuhry, Peter; Maximov, Trofim C.; Hugelius, Gustaf

2015-10-01

Permafrost-affected ecosystems are important components in the global carbon (C) cycle that, despite being vulnerable to disturbances under climate change, remain poorly understood. This study investigates ecosystem carbon storage in two contrasting continuous permafrost areas of NE and East Siberia. Detailed partitioning of soil organic carbon (SOC) and phytomass carbon (PC) is analyzed for one tundra (Kytalyk) and one taiga (Spasskaya Pad/Neleger) study area. In total, 57 individual field sites (24 and 33 in the respective areas) have been sampled for PC and SOC, including the upper permafrost. Landscape partitioning of ecosystem C storage was derived from thematic upscaling of field observations using a land cover classification from very high resolution (2 × 2 m) satellite imagery. Nonmetric multidimensional scaling was used to explore patterns in C distribution. In both environments the ecosystem C is mostly stored in the soil (≥86%). At the landscape scale C stocks are primarily controlled by the presence of thermokarst depressions (alases). In the tundra landscape, site-scale variability of C is controlled by periglacial geomorphological features, while in the taiga, local differences in catenary position, soil texture, and forest successions are more important. Very high resolution remote sensing is highly beneficial to the quantification of C storage. Detailed knowledge of ecosystem C storage and ground ice distribution is needed to predict permafrost landscape vulnerability to projected climatic changes. We argue that vegetation dynamics are unlikely to offset mineralization of thawed permafrost C and that landscape-scale reworking of SOC represents the largest potential changes to C cycling.

Geochemical studies of northern taiga (gypsum) karst ecosystems and their high vulnerability to natural and anthropogenic hazards

NASA Astrophysics Data System (ADS)

Tuyukina, T. Yu.

2009-07-01

In the taiga gypsum karst ecosystems, gypsum soils formed on the hard gypsum substrates predominate in the soil cover. In these soils, the mineral horizons consist of 95-99% gypsum (CaSO4·2H2O) and the litter is the main horizon for nutrient accumulation. For this reason, the ecosystems are vulnerable to fire and erosion by walkers, from which they only recover slowly. Gypsum mining for industrial uses is also leading to the destruction of this unique ecosystem.

The communities of terrestrial macrofungi in different forest types in vicinities of Khanty-Mansiysk (middle taiga zone of West Siberia).

PubMed

Filippova, Nina; Bulyonkova, Tatiana

2017-01-01

The diversity of macrofungi in the vicinities of Khanty-Mansiysk (Yugra, Russia) was surveyed using a method of permanent sampling plots. Ten plots, each consisting of a number of micro-plots, were established in several different communities ranging from old-growth mixed taiga forest to its derivatives in cutting succession and bogged areas. For more complete registration of the mycota, plots were supplemented with random walking routes directly nearby. Survey results were subjected to various quantitative analyses which allowed not only to evaluate the diversity of fungi but also to obtain valuable information on occurrence, abundance and ecology of individual species as well as community structure and its dynamics in the course of ecological succession. The paper reports the results of the first year of observations. 460 species of terrestrial macrofungi revealed in a poorly explored area in middle taiga of West Siberia. The plot-based study revealed differences between communities of terrestrial macrofungi of old coniferous forests, their after-cutting secondary formations and bogged stages. The survey allowed to reveal records of 3 species listed in the Red Data Book of Russia and 9 species listed in the Red Data Book of Yugra.

Mapping of West Siberian taiga wetland complexes using Landsat imagery: Implications for methane emissions

NASA Astrophysics Data System (ADS)

Terentieva, Irina; Sabrekov, Alexander; Glagolev, Mikhail; Maksyutov, Shamil

2017-04-01

Boreal wetlands are important for understanding climate change risks because these environments sink carbon dioxide and emit methane. The West Siberia Lowland (WSL) is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. However, fine-scale heterogeneity of wetland landscapes poses a serious challenge when generating regional-scale estimates of greenhouse gas fluxes from point observations. A number of peatland maps of the West Siberia was developed in 1970s, but their accuracy is limited. In order to reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the WSL on a scene-by-scene basis using a supervised classification of Landsat imagery. Training data consisted of high-resolution images and extensive field data collected at 41 test areas. The classification scheme aimed at supporting methane inventory applications and included 7 wetland ecosystem types comprising 9 wetland complexes distinguishable at the Landsat resolution. To merge typologies, mean relative areas of wetland ecosystems within each wetland complex type were estimated using high-resolution images. Accuracy assessment based on 1082 validation polygons of 10×10 pixels indicated an overall map accuracy of 79%. The total area of the WSL wetlands and water bodies was estimated to be 70.78 Mha or 5-17% of the global wetland area. Various oligotrophic environments are dominant among wetland ecosystems, while different fens cover only 14% of the area. Taiga zone contains 75% of WSL's wetlands; their distribution was described in detail by Terentieva et al. (2016). Concerning methane emission, taiga contributes 85% to regional methane flux and tundra only 8%, however ebullition in tundra lakes was not directly measured. Elevated environments as forested bogs and ridges emit at the lowest rates of methane emission. They account for only 2% of the regional total emissions occupying almost 40% of the wetland

Irreverent Soils: Nitrogen Dynamics In Taiga Forests During Winter

NASA Astrophysics Data System (ADS)

Kielland, K.

2003-12-01

We measured annual net nitrogen mineralization, nitrification, and amino acid production in situ across a primary successional sequence in interior Alaska, USA. Net N mineralization rates during the growing season from green-up (late May) through freeze-up (late September) accounted for approximately 60% of the annual inorganic N flux, whereas the remaining N was released during the apparent dormant season. Nitrogen release during winter occurred primarily during October-January with only negligible N mineralization during early spring in stands of willow, alder, balsam poplar and white spruce. By contrast, black spruce stands also exhibited substantial mineralization after snow melt during early spring. The high rates of N mineralization in late autumn through early winter coincides with high turnover of fine root biomass in these stands, suggesting that labile substrate production, rather than temperature, is a major controlling factor over N release in these ecosystems. The results are consistent with the low temperature sensitivity of N mineralization previously documented for taiga soils, and demonstrate that measurements of soil processes restricted to the growing season may greatly underestimate annual flux rates of inorganic nitrogen in high-latitude ecosystems.

Microbial communities in the litter of middle taiga bilberry-spruce forests

NASA Astrophysics Data System (ADS)

Sizonenko, T. A.; Zagirova, S. V.; Khabibullina, F. M.

2010-10-01

The structure of the microbial communities in the litters of middle-taiga bilberry-spruce forests was studied. It was found that ammonifying and oligonitrophilic microorganisms predominate in these communities. Two maximums in the population density of the microorganisms were observed in June and August. The number of microorganisms increased in the direction from the spruce trunks to the periphery of the crowns. The species composition of the micromycetes in the litters under the spruce crowns and within the intercrown spaces differed. The maximum population density of the fungi was found in the litter under the periphery of the spruce crowns, whereas the maximum diversity of the micromycetes was observed within the intercrown spaces. The Trichoderma, Trichosporiella, Penicillium, Paecilomyces, and Chaetomium genera were most abundant in the litters of the bilberry spruce forests. The Penicillium genus had the maximum abundance during the entire growing period, and the amount of Mycelia sterilia increased in the fall. The maximum diversity of the fungi was observed in May and June.

Influence of Forest-Canopy Morphology and Relief on Spectral Characteristics of Taiga Forests

NASA Astrophysics Data System (ADS)

Zhirin, V. M.; Knyazeva, S. V.; Eydlina, S. P.

2017-12-01

The article deals with the results of a statistical analysis reflecting tendencies (trends) of the relationship between spectral characteristics of taiga forests, indicators of the morphological structure of forest canopy and illumination of the territory. The study was carried out on the example of the model forest territory of the Priangarskiy taiga region of Eastern Siberia (Krasnoyarsk krai) using historical data (forest inventory 1992, Landsat 5 TM 16.06.1989) and the digital elevation model. This article describes a method for determining the quantitative indicator of morphological structure of forest canopy based on taxation data, and the authors propose to subdivide the morphological structure into high complexity, medium complexity, and relatively simple. As a result of the research, dependences of average values of spectral brightness in near and short-wave infrared channels of a Landsat 5 TM image for dark-coniferous, light-coniferous and deciduous forests from the degree of complexity of the forest-canopy structure are received. A high level of variance and maximum brightness average values are marked in green moss (hilocominosa) dark-coniferous and various-grass (larioherbosa) dark-coniferous forests and light-coniferous forests with a complex structure of canopy. The parvifoliate forests are characterized by high values of brightness in stands with a relatively simple structure of the canopy and by a small variance in brightness of any degree of the structure of the canopy complexity. The increase in brightness for the lit slopes in comparison with shaded ones in all stands with a difficult morphological canopy structure is revealed. However, the brightness values of the lit and shaded slopes do not differ for stands with a medium complexity of the structure. It is noted that, in addition to the indicator of the forest-canopy structure, the possible impact on increasing the variance of spectral brightness for the taxation plot has a variability of the

The communities of terrestrial macrofungi in different forest types in vicinities of Khanty-Mansiysk (middle taiga zone of West Siberia)

PubMed Central

Bulyonkova, Tatiana

2017-01-01

Abstract Background The diversity of macrofungi in the vicinities of Khanty-Mansiysk (Yugra, Russia) was surveyed using a method of permanent sampling plots. Ten plots, each consisting of a number of micro-plots, were established in several different communities ranging from old-growth mixed taiga forest to its derivatives in cutting succession and bogged areas. For more complete registration of the mycota, plots were supplemented with random walking routes directly nearby. Survey results were subjected to various quantitative analyses which allowed not only to evaluate the diversity of fungi but also to obtain valuable information on occurrence, abundance and ecology of individual species as well as community structure and its dynamics in the course of ecological succession. The paper reports the results of the first year of observations. New information 460 species of terrestrial macrofungi revealed in a poorly explored area in middle taiga of West Siberia. The plot-based study revealed differences between communities of terrestrial macrofungi of old coniferous forests, their after-cutting secondary formations and bogged stages. The survey allowed to reveal records of 3 species listed in the Red Data Book of Russia and 9 species listed in the Red Data Book of Yugra. PMID:29362551

Low to middle tropospheric profiles and biosphere/troposphere fluxes of acidic gases in the summertime Canadian taiga

NASA Technical Reports Server (NTRS)

Klemm, O.; Talbot, R. W.; Fitzgerald, D. R.; Klemm, K. I.; Lefer, B. L.

1994-01-01

We report features of acidic gases in the troposphere from 9 to 5000 m altitude above ground over the Canadian taiga in the summer of 1990. The measurements were conducted at a 30-m meteorological tower and from the NASA Wallops Electra aircraft as part of the joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) 3B Northern Wetland Studies (NOWES). We sampled air for acidic gases using the mist chamber collector coupled with subsequent analysis using ion chromatography. At the tower we collected samples at two heights during a 13-day period, including diurnal studies. Using eddy flux and profile data, we estimated the biosphere/troposphere fluxes of nitric, formic, and acetic acids and sulfur dioxide. For the organic acids, emissions from the taiga in the afternoon hours and deposition during the predawn morning hours were observed. The flux intensities alone were however not high enough to explain the observed changes in mixing ratios. The measured deposition fluxes of nitric acid were high enough to have a significant influence on its mixing ratio in the boundary layer. On three days we measured vertical profiles of nitric, formic, and acetic acids through the lower to midtroposphere. We found that the chemical composition of the troposphere was extremely heterogenous. Pronounced layers of polluted air were readily apparent from our measurements. Local photochemical production and episodic long-range transport of trace components, originating from biomass burning and possibly industrial emissions, appear to have a strong influence on the composition of the troposphere and biosphere/troposphere fluxes of acidic gases at this site.

[Soil functioning in foci of Siberian moth population outbreaks in the southern taiga subzone of Central Siberia].

PubMed

Krasnoshchekov, Iu N; Beskorovaĭnaia, I N

2008-01-01

The results of experimental studies on the contribution of zoogenic debris to transformation of soil properties in the southern taiga subzone of Central Siberia are analyzed. They show that water-soluble carbon outflow from the forest litter increases by 21-26% upon a Siberian moth invasion, with this value decreasing to 14% one year later. The burning of forest in an area completely defoliated by the pest leads to changes in the stock, fractional composition, actual acidity, and ash element contents of the litter. The litter-dwelling invertebrate assemblage is almost completely destroyed by fire and begins to recover only after two years.

Analyse dendroecologique et dendroclimatique des gisements de bois de lacs de la taiga de l'est de l'Amerique du Nord

NASA Astrophysics Data System (ADS)

Gennaretti, Fabio

The aim of this thesis was to reconstruct ecological processes and climate change in the taiga of Quebec over the last two millennia to understand factors that have strongly influenced the evolution of this majestic region. To obtain the finest spatial and temporal resolution in our analysis, we used annual growth rings of subfossil logs collected in six lakes as paleoecological and paleoclimatic proxies. Deposits of subfossil logs determine the structure of lake littoral ecosystems and support their food webs. Moreover, they may represent long-term carbon sinks. In the first chapter of the thesis, we described present-day stocks of subfossil logs in the selected littoral zones and established log residence time in the lakes by tree-ring or radio carbon dating. Dating also allowed precise identification of each fire that burned the riparian forests during the last millennium. This chapter showed that interactions between terrestrial and aquatic ecosystems in the taiga are strongly influenced by wildfires whose effects can persist for centuries because of strong postfire reductions of log recruitments in lakes. At a local scale, the amount of logs and carbon preserved in littoral stocks depends on the fire history of the last millennium that is specific to each site. At a regional scale, wildfires limit significantly the amount of carbon sequestered in littoral stocks of logs. These stocks represent a negligible fraction of the total taiga carbon storage despite the abundance of lakes and the long residence time of littoral logs (up to five millennia for buried logs). In the second chapter, we combined a detailed inventory of the present-day riparian forest situated along the shoreline of two lakes with the tree-ring dating of the subfossil logs accumulated in the littoral zones facing these shores. Our objective was to determine whether changes in current riparian forest structure and composition within a given site could be attributed to different fire histories

Climatically induced interannual variability in aboveground production in forest-tundra and northern taiga of central Siberia.

PubMed

Knorre, Anastasia A; Kirdyanov, Alexander V; Vaganov, Eugene A

2006-02-01

To investigate the variability of primary production of boreal forest ecosystems under the current climatic changes, we compared the dynamics of annual increments and productivity of the main components of plant community (trees, shrubs, mosses) at three sites in the north of Siberia (Russia). Annual radial growth of trees and shrubs was mostly defined by summer temperature regime (positive correlation), but climatic response of woody plants was species specific and depends on local conditions. Dynamics of annual increments of mosses were opposite to tree growth. The difference in climatic response of the different vegetation components of the forest ecosystems indicates that these components seem to be adapted to use climatic conditions during the short and severe northern summer, and decreasing in annual production of one component is usually combined with the increase of other component productivity. Average productivity in the northern forest ecosystems varies from 0.05 to 0.14 t ha(-1) year(-1) for trees, from 0.05 to 0.18 t ha(-1) year(-1) for shrubs and from 0.54 to 0.66 t ha(-1) year(-1) for mosses. Higher values of tree productivity combined with lower annual moss productivity were found in sites in northern taiga in comparison with forest-tundra. Different tendencies in the productivity of the dominant species from each vegetation level (trees, shrubs, mosses) were indicated for the last 10 years studied (1990-1999): while productivity of mosses is increasing, productivity of trees is decreasing, but there is no obvious trend in the productivity of shrubs. Our results show that in the long term, the main contribution to changes in annual biomass productivity in forest-tundra and northern taiga ecosystems under the predicted climatic changes will be determined by living ground cover.

Distribution of global fallouts cesium-137 in taiga and tundra catenae at the Ob River basin

NASA Astrophysics Data System (ADS)

Semenkov, I. N.; Usacheva, A. A.; Miroshnikov, A. Yu.

2015-03-01

The classification of soil catenae at the Ob River basin is developed and applied. This classification reflects the diverse geochemical conditions that led to the formation of certain soil bodies, their combinations and the migration fields of chemical elements. The soil and geochemical diversity of the Ob River basin catenae was analyzed. The vertical and lateral distribution of global fallouts cesium-137 was studied using the example of the four most common catenae types in Western Siberia tundra and taiga. In landscapes of dwarf birches and dark coniferous forests on gleysols, cryosols, podzols, and cryic-stagnosols, the highest 137Cs activity density and specific activity are characteristic of the upper soil layer of over 30% ash, while the moss-grass-shrub cover is characterized by low 137Cs activity density and specific activity. In landscapes of dwarf birches and pine woods on podzols, the maximum specific activity of cesium-137 is typical for moss-grass-shrub cover, while the maximum reserves are concentrated in the upper soil layer of over 30% ash. Bog landscapes and moss-grass-shrub cover are characterized by a minimum activity of 137Cs, and its reserves in soil generally decrease exponentially with depth. The cesium-137 penetration depth increases in oligotrophic histosols from northern to middle taiga landscapes from 10-15 to 40 cm. 137Cs is accumulated in oligotrophic histosols for increases in pH from 3.3 to 4.0 and in concretionary interlayers of pisoplinthic-cryic-histic-stagnosols. Cryogenic movement, on the one hand, leads to burying organic layers enriched in 137Cs and, on the other hand, to deducing specific activity when mixed with low-active material from lower soil layers.

[PCR identification of DNA of hosts of the taiga tick nymphs (Ixodes persulcatus: Ixodinae) in St. Petersburg and its suburbs].

PubMed

Grigor'eva, L A; Markov, A V

2011-01-01

PCR identification of host DNA in unfed females and males of taiga tick Ixodes persulcatus was performed. Amplification of each sample was done using primers species-specific by 12S rDNA mitochondrial gene. Four species of small mammals (Apodemus uralensis, Clethrionomys glareolus, Microtus arvalis, and Sorex araneus) and two passeriform bird species (Fringilla coelebs and Parus major) were analysed. For one third of tick samples, hosts of previous stages were established using this method. In five cases, feeding on more than one host species was detected.

Short-term standard litter decomposition across three different ecosystems in middle taiga zone of West Siberia

NASA Astrophysics Data System (ADS)

Filippova, Nina V.; Glagolev, Mikhail V.

2018-03-01

The method of standard litter (tea) decomposition was implemented to compare decomposition rate constants (k) between different peatland ecosystems and coniferous forests in the middle taiga zone of West Siberia (near Khanty-Mansiysk). The standard protocol of TeaComposition initiative was used to make the data usable for comparisons among different sites and zonobiomes worldwide. This article sums up the results of short-term decomposition (3 months) on the local scale. The values of decomposition rate constants differed significantly between three ecosystem types: it was higher in forest compared to bogs, and treed bogs had lower decomposition constant compared to Sphagnum lawns. In general, the decomposition rate constants were close to ones reported earlier for similar climatic conditions and habitats.

(abstract) Monitoring Seasonal Change in Taiga Forests Using ERS-1 SAR Data

NASA Technical Reports Server (NTRS)

Way, JoBea; Rignot, Eric; McDonald, Kyle; Viereck, Leslie; Williams, Cynthia; Adams, Phyllis; Payne, Cheryl; Wood, William

1993-01-01

Sensitivity of radar backscatter to the dielectric and geometric character of forested regions suggests significant changes in backscatter are expected with season due to freezing temperatures, snow, wind, leaf fall, and drought. The first European Remote Sensing Satellite, ERS-1, offers a unique opportunity to monitor a complete seasonal cycle for the Alaskan taiga forest ecosystem with synthetic aperture radar. During the 3-day repeat Commissioning Phase of ERS-1, from August 1991to December 1991, ERS-1 SAR data were collected in the region of Manley Hot Springs, Alaska, along the Tanana River, west of Fairbanks. In parallel with the SAR data collection, meteorological data from three weather stations positioned in three forest stands were collected continuously along with in situ measurements of the dielectric and moisture properties of the canopy and of ground cover which were collected during each overflight. The in situ data were collected in floodplain forest stands dominated by balsam poplar, white spruce, and black spruce. These results from the Commissioning Phase as well as preliminary results from the 35-day Repeat Phase will be presented.

[Diversity of soil mesofauna in Northern Taiga biogeocenosises of the Kamennaya river basin (Karelia)].

PubMed

Rybalov, L B; Kamaev, I O

2011-01-01

The population of soil mesofauna in the basin of the small river subzone of the northern taiga (Karelia) has been investigated. It was shown that indexes of the number and mass of soil mesofauna in the landscape-ecological row ofbiogeocenosises are maximal in floodplain soils. The taxonomic composition and structure of domination of the soil mesofauna population depends on the location of biogeocenosis in the landscape: earthworms are dominants in riverine floodplain biogeocenosises, and larvae of elaterids and spiders prevail in the places outside of floodplains. The abundance of saprophytic invertebrates in floodplain biogeocenosises results in formation of humus of the mull type. A group of animals with mixed type of nutrition dominates in the places outside of floodplain soils that are related with humus of the moder-mor type. The population of rove beetles (Staphylinidae) allows the division of biogeocenosises into two groups according to their position in the landscape.

Soil catenas on denudation plains in the forest-tundra and northern taiga zones of the Kola Peninsula

NASA Astrophysics Data System (ADS)

Urusevskaya, I. S.

2017-07-01

Morphogenetic features of soils of two catenas developed on sandy to loamy sandy moraine deposits in the forest-tundra and northern taiga zones on denudation plains of the Kola Peninsula are discussed. It is shown that these catenas are similar with respect to the major directions of soil formation, regularities of soil distribution by the elements of mesotopography, and the factors of the soil cover differentiation. The differences between the catenas are of quantitative character and are related to the intensities of manifestation of the particular processes and features. Both catenas are characterized by the pronounced differentiation of soils with respect to their moistening with hydromorphic peat bog soils in the subordinate positions and Al-Fe-humus podzols in the automorphic positions.

Simulation of the hybrid Tunka Advanced International Gamma-ray and Cosmic ray Astrophysics (TAIGA)

NASA Astrophysics Data System (ADS)

Kunnas, M.; Astapov, I.; Barbashina, N.; Beregnev, S.; Bogdanov, A.; Bogorodskii, D.; Boreyko, V.; Brückner, M.; Budnev, N.; Chiavassa, A.; Chvalaev, O.; Dyachok, A.; Epimakhov, S.; Eremin, T.; Gafarov, A.; Gorbunov, N.; Grebenyuk, V.; Gress, O.; Gress, T.; Grinyuk, A.; Grishin, O.; Horns, D.; Ivanova, A.; Karpov, N.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kirichkov, N.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Konstantinov, E.; Korobchenko, A.; Korosteleva, E.; Kozhin, V.; Kuzmichev, L.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Perevalov, A.; Petrukhin, A.; Platonov, V.; Poleschuk, V.; Popescu, M.; Popova, E.; Porelli, A.; Porokhovoy, S.; Prosin, V.; Ptuskin, V.; Romanov, V.; Rubtsov, G. I.; Müger; Rybov, E.; Samoliga, V.; Satunin, P.; Saunkin, A.; Savinov, V.; Semeney, Yu; Shaibonov (junior, B.; Silaev, A.; Silaev (junior, A.; Skurikhin, A.; Slunecka, M.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Veslopopov, A.; Veslopopova, E.; Voronov, D.; Wischnewski, R.; Yashin, I.; Yurin, K.; Zagorodnikov, A.; Zirakashvili, V.; Zurbanov, V.

2015-08-01

Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion quality and gamma-hadron separation power. However, sensitive observations at and above 100 TeV require very large effective areas (10 km2 and more), which is difficult and expensive to achieve. The alternative to IACTs are shower front sampling arrays (non-imaging technique or timing-arrays) with a large area and a wide field of view. Such experiments provide good core position, energy and angular resolution, but only poor gamma-hadron separation. Combining both experimental approaches, using the strengths of both techniques, could optimize the sensitivity to the highest energies. The TAIGA project plans to combine the non-imaging HiSCORE [8] array with small (∼10m2) imaging telescopes. This paper covers simulation results of this hybrid approach.

Soils in seasonally flooded forests as methane sources: A case study of West Siberian South taiga

NASA Astrophysics Data System (ADS)

Mochenov, S. Yu; Churkina, A. I.; Sabrekov, S. F.; Glagolev, M. V.; Il’yasov, D. V.; Terentieva, I. E.; Maksyutov, S. S.

2018-03-01

In this study, we measured the methane and carbon dioxide fluxes by static chamber method from the soil of periodically flooded forests under different water table levels (WTL) in West Siberian south taiga (Tomsk oblast, Russia) in summer seasons of 2016 and 2017 years. The study shows that seasonally flooded forests may become a methane source when the WTL increases up to 15-45 cm below the surface. The fluxes of methane from soil were from -0.08±0.07 to 9.3±0.8 mg·m-2·h-1, from 0.05±0. 04 to 0.14±0.13 mg·m-2·h-1, from - 0.03±0.02 to 5.4±0.2 mg·m-2·h-1 depending on variou s WTL in different seasonally flooded forests in 2017.

Calibration and Validation of Landsat Tree Cover in the Taiga-Tundra Ecotone

NASA Technical Reports Server (NTRS)

Montesano, Paul Mannix; Neigh, Christopher S. R.; Sexton, Joseph; Feng, Min; Channan, Saurabh; Ranson, Kenneth J.; Townshend, John R.

2016-01-01

Monitoring current forest characteristics in the taiga-tundra ecotone (TTE) at multiple scales is critical for understanding its vulnerability to structural changes. A 30 m spatial resolution Landsat-based tree canopy cover map has been calibrated and validated in the TTE with reference tree cover data from airborne LiDAR and high resolution spaceborne images across the full range of boreal forest tree cover. This domain-specific calibration model used estimates of forest height to determine reference forest cover that best matched Landsat estimates. The model removed the systematic under-estimation of tree canopy cover greater than 80% and indicated that Landsat estimates of tree canopy cover more closely matched canopies at least 2 m in height rather than 5 m. The validation improved estimates of uncertainty in tree canopy cover in discontinuous TTE forests for three temporal epochs (2000, 2005, and 2010) by reducing systematic errors, leading to increases in tree canopy cover uncertainty. Average pixel-level uncertainties in tree canopy cover were 29.0%, 27.1% and 31.1% for the 2000, 2005 and 2010 epochs, respectively. Maps from these calibrated data improve the uncertainty associated with Landsat tree canopy cover estimates in the discontinuous forests of the circumpolar TTE.

NDVI dynamics of the taiga zone in connection with modern climate changes

NASA Astrophysics Data System (ADS)

Bobkov, A.; Panidi, E.; Torlopova, N.; Tsepelev, V.

2015-04-01

This research is dedicated to the investigation of the relations between the XXI century climate changes and Normalized Difference Vegetation Index (NDVI) variability of the taiga zone. For this purposes was used the observations of vegetation variability on the test area located nearby Syktyvkar city (Komi Republic, Russia), 16-day averages of NDVI data derived from TERRA/MODIS space imagery (spatial resolution is about 250 meters), and the air temperature and precipitation observations from Syktyvkar meteorological station. The research results confirmed the statistically significant positive correlation between NDVI and air temperature for all vegetation types of the test area, for both spring and autumn seasons. The weakest correlation was found for coniferous forest, namely, pine forest on poor soils, and the strongest correlation was found for meadows and bogs. Additionally the map of NDVI trends of the test area shows that the sectors of greatest positive trend located on the territories with non-forest cover, and as a result, the positive trend of air temperature is indicated most brightly on vegetation of non-forest lands. Thereby these lands can serve as climate changes indicator in the investigated region. The study was partially supported by Russian Foundation for Basic Research (RFBR), research project No. 14-05-00858 a.

[Microorganisms of the order Rickettsiales in taiga tick (Ixodes persulcatus Sch.) from the Pre-Ural region].

PubMed

Nefedova, V V; Korenberg, E I; Kovalevskiĭ, Iu V; Gorelova, N B; Vorob'eva, N N

2008-01-01

The PCR and sequence analysis revealed DNA Ehrlichia muris, Anaplasma phagocytophilum, and Rickettsia spp. in the I. persulcatus ticks and blood samples from a patients with acute febrile illness occurring after a tick bite, registered in the seasonal peak of the tick activity of one of the highly endemic areas of Russia (Perm region). These data confirmed the validity a diagnosis of HME and HGA, which were made earlier on the basis of the clinical-serologic survey. In 10.0% of the tested taiga ticks were detected DNA of two and more agents in various combinations i.e. E. muris and Rickettsia spp, A. phagocytophilum and Rickettsia spp., and E. muris, A. phagocytophilum and Rickettsia spp. DNA of a R. helvetica was detected in I. persulcatus tick and blood tick-bitten patient with febrile episodes. Probably that R. helvetica can be etiological agent in some part of cases with the serologically unconfirmed diagnoses of acute feverish diseases developing after tick bite.

[Conjugated variability of spontaneous activity and behavioral response to olfactory stimuli in the taiga tick (Ixodes persulcatus)].

PubMed

Romashchenko, A V; Shnaĭder, E P; Petrovskiĭ, D V; Moshkin, M P

2013-01-01

According to -the automatic tracing of the movement of ticks in a Petri dish, motivational variability of the spontaneous activity and behavioral response of the taiga tick to olfactory stimuli was analyzed. In the studied sample, two groups of ticks that differ in the movement trajectory in the absence of stimulus were isolated, including ticks that mainly moved on the edge of the dish at maximum accessible height (group 1) and ticks that mainly moved at the bottom and wall of the dish (group 2). It was registered that ticks of group 1 (as opposed to ticks of group 2) demonstrated a pronounced behavioral response to olfactory stimuli (human synthetic pheromones and ammonia) and negative geotaxis. It was established that belonging to these groups depended On the time of day when the testing was performed and did not depend on the physiological age and infectious status.

Permafrost thaw and wildfire: Equally important drivers of boreal tree cover changes in the Taiga Plains, Canada

NASA Astrophysics Data System (ADS)

Helbig, M.; Pappas, C.; Sonnentag, O.

2016-02-01

Boreal forests cover vast areas of the permafrost zones of North America, and changes in their composition and structure can lead to pronounced impacts on the regional and global climate. We partition the variation in regional boreal tree cover changes between 2000 and 2014 across the Taiga Plains, Canada, into its main causes: permafrost thaw, wildfire disturbance, and postfire regrowth. Moderate Resolution Imaging Spectroradiometer Percent Tree Cover (PTC) data are used in combination with maps of historic fires, and permafrost and drainage characteristics. We find that permafrost thaw is equally important as fire history to explain PTC changes. At the southern margin of the permafrost zone, PTC loss due to permafrost thaw outweighs PTC gain from postfire regrowth. These findings emphasize the importance of permafrost thaw in controlling regional boreal forest changes over the last decade, which may become more pronounced with rising air temperatures and accelerated permafrost thaw.

Microbial activity in Alaskan taiga soils contaminated by crude oil in 1976

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

Monroe, E.M.; Lindstrom, J.E.; Brown, E.J.

1995-12-31

Biodegradation, often measured via microbial activity, includes destruction of environmental pollutants by living microorganisms and is dependent upon many physical and chemical factors. Effects of mineral nutrients and organic matter on biodegradation of Prudhoe Bay crude oil were investigated at a nineteen-year-old oil spill site in Alaskan taiga. Microcosms of two different soil types from the spill site; one undeveloped soil with forest litter and detritus (O horizon) and one more developed with lower organic content (A horizon), were treated with various nitrogen and phosphorus amendments, and incubated for up to six weeks. Each microcosm was sampled periodically and assayedmore » for hydrocarbon mineralization potential using radiorespirometry, for total carbon dioxide respired using gas chromatography, and for numbers of hydrocarbon-degrading bacteria and heterotrophic bacteria using most probable number counting techniques. Organic matter in the O horizon soil along with combinations of mineral nutrients were found to stimulate microbial activity. No combination of mineral nutrient additions to the A horizon soil stimulated any of the parameters above those measured in control microcosms. The results of this study indicate that adding mineral nutrients and tilling the O horizon into the A horizon of subarctic soils contaminated with crude oil, would stimulate microbial activity, and therefore the biodegradation potential, ultimately increasing the rate of destruction of crude oil in these soils.« less

Temporal variability of methane fluxes in West Siberian taiga bogs and its implications for estimating regional methane emission

NASA Astrophysics Data System (ADS)

Sabrekov, Alexander; Ilyasov, Danil; Terentieva, Irina; Glagolev, Mikhail; Maksyutov, Shamil

2017-04-01

The West Siberia Lowland (WSL) is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. During 2015-16 summer periods, seasonal measurements of methane emission were made at the field station «Mukhrino» in the WSL middle taiga zone. The study was made at 3 wetland ecosystem types covering 80% of the taiga wetland area: i) waterlogged hollows or depressed areas with water level above the moss surface, ii) oligotrophic hollows or depressed parts of bogs with water level beneath the moss surface, iii) forested bogs with dwarf shrubs-sphagnum vegetation. Seven series of measurements were made by a static chamber method in 2016 and four series - in 2015. In 2015, we observed non-typical weather conditions including early dry spring and short cold rainy summer. Oppositely, weather conditions in 2016 were closer to average long-term with warmer drier summer. Significant difference between these years allowed analyzing the temporal variability and its sources. Average methane flux rates from forested bogs were 0.57 mgCH4/m2/h in 2016 and 0.33 mgCH4/m2/h in 2015. Seasonal dynamic during both years had similar concave downward shape. The highest fluxes were observed in June and were corresponded to the highest WTL, the main limiting factor of emission from forested bogs. The lowest fluxes in July were related to the low WTL combining with the highest temperature of upper methanotrophy layer. Average methane flux rates from oligotrophic hollows were 7.18 mgCH4/m2/h in 2016 and 4.28 mgCH4/m2/h in 2015. Seasonal dynamic of methane emission was indistinct in 2015. On the contrary, in 2016 it had regular seasonal pattern with peak emissions in July, which were four times higher than in 2015. WTL was not the limiting factor for CH4 emission from oligotrophic hollows, because even in the driest ones it was only 10 cm below the surface. Thus, the difference between peak emissions in 2015 and 2016 was mainly related

Methane and carbon dioxide fluxes in the waterlogged forests of south and middle taiga of Western Siberia

NASA Astrophysics Data System (ADS)

Glagolev, M. V.; Ilyasov, D. V.; Terentieva, I. E.; Sabrekov, A. F.; Mochenov, S. Yu; Maksutov, S. S.

2018-03-01

Field measurements of methane and carbon dioxide flux were carried out using portable static chambers in south (ST) and middle taiga subzones (MT) of Western Siberia (WS) from 16 to 24 August 2015. Two sites were investigated: Bakchar bog in the Tomsk region (in typical ecosystems for this area: oligotrophic bog/forest border and waterlogged forest) and Shapsha in Khanty-Mansiysk region (in waterlogged forest). The highest values of methane fluxes (mgC·m-2·h-1) were obtained in burnt wet birch forest (median 6.96; first quartile 3.12; third quartile 8.95). The lowest values of methane fluxes (among the sites mentioned above) were obtained in seasonally waterlogged forests (median -0.08; first and third quartiles are -0.14 and -0.03 mgC·m-2·h-1 respectively). These data will help to estimate the regional methane flux from the waterlogged and periodically flooded forests and to improve its prediction.

Carbon emission from the soil surface in a mature blueberry pine forest of the middle taiga (Republic of Komi)

NASA Astrophysics Data System (ADS)

Osipov, A. F.

2016-08-01

Data on the input of plant falloff and organic matter decomposition on the surface of the peaty podzolic-gleyic humus-illuvial (Gleyic Podzol) soil under a mature blueberry pine forest in the middle taiga are presented. The fractional composition of the falloff was determined, and constants of decomposition for its components were calculated. The carbon flux to the atmosphere due to the mineralization of plant residues is estimated at 251 g/m2. A close positive correlation ( r = 0.71; P < 0.05) was found between the carbon dioxide emission measured using a gas analyzer and the soil temperature at the depth of 10 cm. The CO2 emission for a growing period calculated from the data on its dependence on soil temperature in different years varied from 243 to 313 g C/m2 and was related to weather conditions.

Life cycle of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in the North-West of Russia.

PubMed

Grigoryeva, L A; Stanyukovich, M K

2016-07-01

The life cycle of Ixodes persulcatus lasts 3 years in the conditions of the Leningrad province (North-West Russia), the development of each phase taking a year. The normal age of the taiga tick is 3 years. The calendar age of larvae and nymphs reaches 11-12 months under favorable abiotic and biotic factors, while the calendar age of adults does not exceed 11 months. At the preimaginal phases of development the ticks that breed in August can feed before or after winter. However, their metamorphosis begins and reaches completion within the same timeframes (from late June to early August) and lasts for about 30-50 (60) days. The survival rate of hungry and engorged larvae and nymphs after wintering is quite high (88.6-100 %). We explain the low activity of larvae and nymphs in late summer and autumn by incomplete development. Morphogenetic diapause of engorged larvae and nymphs interrupts digestion but not metamorphosis which starts only in late June and July after the complete absorption of blood from the gut cavity.

Alvar soils and ecology in the boreal forest and taiga regions of Canada.

NASA Astrophysics Data System (ADS)

Ford, D.

2012-04-01

Alvars have been defined as "...a biological association based on a limestone plain with thin or no soil and, as a result, sparse vegetation. Trees and bushes are stunted or absent ... may include prairie spp." (Wikipedia). They were first described in southern Sweden, Estonia, the karst pavements of Yorkshire (UK) and the Burren (Eire). In North America alvars have been recognised and reported only in the Mixed Forest (deciduous/coniferous) Zone around the Great Lakes. An essential feature of the hydrologic controls on vegetation growth on natural alvars is that these terrains were glaciated in the last (Wisconsinan/Würm) ice age: the upper beds of any pre-existing epikarst were stripped away by glacier scour and there has been insufficient time for post-glacial epikarst to achieve the depths and densities required to support the deep rooting needed for mature forest cover. However, in the sites noted above, the alvars have been created, at least in part, by deforestation, overgrazing, burning to create browse, etc. and thus should not be considered wholly natural phenomena. There are extensive natural alvars in the Boreal Forest and Taiga ecozones in Canada. Their nature and variety will be illustrated with examples from cold temperate maritime climate settings in northern Newfoundland and the Gulf of St Lawrence and cold temperate continental to sub-arctic climates in northern Manitoba and the Northwest Territories.

The mesofauna in different types of soils under southern taiga spruce forests (Tver oblast)

NASA Astrophysics Data System (ADS)

Gryuntal, S. Yu.

2010-11-01

The soil mesofauna of the burozem, soddy pale-podzolic, and whitish-podzolic soils under three types of southern taiga spruce forests was studied. The mesofauna of all these soils turned out to be similar in terms of the Chilopoda, Staphylinidae (Coleoptera), and Rhagionidae (Diptera) numbers and their predominant concentration in the litter. The zoophages prevailed, and, among the saprophages, primary destroyers were predominant. However, some specific characteristics of the mesofauna in the soils studied were revealed. In the sequence burozem, soddy pale-podzolic, and whitish-podzolic soils, the number of earthworms significantly decreased, while, in the sequence soddy pale-podzolic, burozem, and whitish-podzolic soils, the number of Diplopoda representatives and calciphilic forms became lower and was directly related to the diversity of the deciduous tree species and to the presence of the calcareous moraine close to the surface. In addition, some species can be indicators of particular soil properties. The presence of the road beetle Quedius fuliginosus indicated the elevated moisture of the soils, that of Philonthus decorus pointed to the high humus content, and the presence of the road beetle Tachinus marginellus showed the low acidity of the humus. The low number or the absence of the earthworms Octolasium lacteum and Dendrodril us rubidus f. tenuis indicated higher humus acidity.

Natural resource inventory and monitoring for Ulaan Taiga Specially Protected Areas—An assessment of needs and opportunities in northern Mongolia

USGS Publications Warehouse

Moore, Peggy E.; Meyer, Joseph B.; Chow, Leslie S.

2017-03-10

Between 1997 and 2011, Mongolia established three specially protected areas in the north-central part of the country to protect various high-value resources. These areas are jointly referred to as the Ulaan Taiga Specially Protected Areas. In accordance with the goals of the draft general management plan, this report identifies options for initiating an inventory and monitoring program for the three protected areas. Together, the three areas comprise over 1.5 million hectares of mountainous terrain west of Lake Hovsgol and bordering the Darkhad Valley. The area supports numerous rare ungulates, endangered fish, and over 40 species of threatened plants. Illegal mining, illegal logging, and poaching pose the most immediate threats to resources. As a first step, a review of published literature would inform natural resource management at the Ulaan Taiga Specially Protected Areas because it would inform other inventories.Vegetation classification and mapping also would inform other inventory efforts because the process incorporates geographic analysis to identify environmental gradients, fine-scale sampling that captures species composition and structure, and landscape-scale results that represent the variety and extent of habitats for various organisms. Mapping using satellite imagery reduces the cost per hectare.Following a determination of existing knowledge, field surveys of vertebrates and vascular plants would serve to build species lists and fill in gaps in existing knowledge. For abiotic resources, a focus on monitoring air quality, evaluating and monitoring water quality, and assembling and storing weather data would provide information for correlating resource response status with changing environmental conditions.Finally, we identify datasets that, if incorporated into a geographic information system, would inform resource management. They include political boundaries, infrastructure, topography, surficial geology, hydrology, fire history, and soils.In terms

Object-based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

NASA Technical Reports Server (NTRS)

Ransom, Kenneth J.; Montesano, Paul M.; Nelson, Ross F.

2011-01-01

The circumpolar taiga-tundra ecotone was delineated using an image segmentation based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 - 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation grouped pixels representing similar tree cover into polygonal features (objects) that form the map of the transition zone. Eachfeature represents an area much larger than the 500m MODIS pixel to characterize thepatterns of sparse forest patches on a regional scale. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1deg longitudinal interval in North America and Eurasia and (2) Landsat-derived Canadianproportion of forest cover for Canada. The adjusted TCC from MODIS VCF shows, on average, greater than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values between 5-20% , or (2) mean adjusted TCC values <5% but with a standard deviation > 5% were used to identify the ecotone.

[EXOSKELETON ABNORMALITIES IN TAIGA TICK FEMALES FROM POPULATIONS OF THE ASIATIC PART OF RUSSIA].

PubMed

Nikitin, A Ya; Morozov, I M

2016-01-01

Studies of the phenotypic structure of Ixodes persulcatus (Schulze, 1930) populations in relation to their exoskeleton abnormalities are important in both theoretical and practical respects. The data on the species' population structure in Asiatic part of Russia are fragmentary. The goal of the study was to describe taiga tick population structure based on the pattern of females' exoskeleton abnormalities revealed in Asiatic part of Russia. A total of 3872 I. persulcatus females from 16 geographically remote sites of Far Eastern, Siberian, and Ural Federal Districts (FEFD, SFD, and UFD accordingly) were studied. It was demonstrated that all the populations possessed specimens with exoskeleton abnormalities. The «shagreen skin» abnormality was dominant in all these areas. At the same time, the percentage of abnormalities among the specimens collected to the north of 55°N is considerably higher (63.4 ± 3.39 %) than that of samples from the SFD southward territories (33.1 ± 3.43 %). The frequency of abnormalities in its turn is lower (24.4 ± 1.93 %) in the females from the territories with moderate monsoon and moderate continental climate (FEFD) than that in specimens from SFD and UFD areas with sharp continental climate. Thus, such polymorphism of the females' exoskeleton structure may reflect the natural phenogeographical variability of the character rather than the result of the anthropogenic impact. 403

Spaceborne Potential for Examining Taiga-Tundra Ecotone Form and Vulnerability

NASA Technical Reports Server (NTRS)

Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

2016-01-01

In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable and widespread vegetation change warrants the application of spaceborne data including high-resolution (less than 5m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch-scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data, and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at approximately 40%, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms, and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the

Spaceborne potential for examining taiga-tundra ecotone form and vulnerability

NASA Astrophysics Data System (ADS)

Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

2016-07-01

In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density, and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable, and widespread vegetation change warrants the application of spaceborne data including high-resolution (< 5 m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at ˜ 40 %, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the TTE to climate

Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).

NASA Astrophysics Data System (ADS)

Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.

2012-04-01

Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation

Bayesian multiproxy temperature reconstruction with black spruce ring widths and stable isotopes from the northern Quebec taiga

NASA Astrophysics Data System (ADS)

Gennaretti, Fabio; Huard, David; Naulier, Maud; Savard, Martine; Bégin, Christian; Arseneault, Dominique; Guiot, Joel

2017-12-01

Northeastern North America has very few millennium-long, high-resolution climate proxy records. However, very recently, a new tree-ring dataset suitable for temperature reconstructions over the last millennium was developed in the northern Quebec taiga. This dataset is composed of one δ18O and six ring width chronologies. Until now, these chronologies have only been used in independent temperature reconstructions (from δ18O or ring width) showing some differences. Here, we added to the dataset a δ13C chronology and developed a significantly improved millennium-long multiproxy reconstruction (997-2006 CE) accounting for uncertainties with a Bayesian approach that evaluates the likelihood of each proxy model. We also undertook a methodological sensitivity analysis to assess the different responses of each proxy to abrupt forcings such as strong volcanic eruptions. Ring width showed a larger response to single eruptions and a larger cumulative impact of multiple eruptions during active volcanic periods, δ18O showed intermediate responses, and δ13C was mostly insensitive to volcanic eruptions. We conclude that all reconstructions based on a single proxy can be misleading because of the possible reduced or amplified responses to specific forcing agents.

Analyses of changes in vegetation cover in the South and Sub-Taiga of Western Siberia using Landsat data

NASA Astrophysics Data System (ADS)

Dyukarev, Egor; Pologova, Nina; Golovatskaya, Eugenia

2010-05-01

Understanding human impact on vegetation composition and structure, at scales from the patch to the globe, and capacity to monitor change over time is fundamental research problem to address Global Change and ensure sustainable development. Natural ecosystems at the South and Sob-Taiga zone of Western Siberia are characterized by development of an early successional states, given the projected increase in disturbance, or will be converted into human-dominated terrestrial production systems. Disturbances (e.g., fire, dieback due to insect attacks) appear to be increasing in some regions, leading to fragmentation of natural ecosystems and to a generally "weedier," structurally simpler biosphere with fewer systems in a more ecologically complex old-growth state. The analysis of structure of vegetation cover at two test sites located at the south-west part of the West-Siberian Plain in the South and Sub-Taiga zone was made using LANDSAT space images and ground data. The studied area of the first test site ("Bakchar") is occupied by bogs, paludificated forests and cultivated lands. Test site "Tomsk" covered by cultivated lands in the south, dark coniferous forest complexes an early and old-growth state in the north part. Mire types at the test sites are presented by open fens, ridge-hollow / ridge-lake complexes and pine-shrub-sphagnum communities with different tree height and layer density. During the XX century the vegetation cover was exposed to natural and anthropogenic changes. Comparison of space images from different years (1990, 1999 and 2007) allowed revealing dynamics in vegetation cover. Forest change was calculated using the Disturbance Index (Healey, 2006). Decrease of forest area in 1990-1999 are primary occurs due to intense forest cutting for timber industry and local use. A strong wind have damaged forests between 1990 and 1999 in stripes oriented from south-west to north -east in the prevailing wind direction. Strong winds were registered in 2003

Features of seasonal temperature variations in peat soils of oligotrophic bogs in south taiga of Western Siberia

NASA Astrophysics Data System (ADS)

Kiselev, M. V.; Dyukarev, E. A.; Voropay, N. N.

2018-03-01

The work presents the results of the study of the peculiarities of the temperature regime in the five basic ecosystems of oligotrophic bogs in the south taiga zone of Western Siberia in 2011-2016. The soil temperature regime was studied using the atmospheric-soil measuring complex at different depths from surface down to 240 cm. All sites were divided into two groups according to the bog water level: flooded sites (hollow and open fen) and drained sites (ridge, tall and low ryam). The waterlogged sites are better warmed in the summer period and slowly freeze in the winter period. The analysis of the annual cycle of temperature showed that the maximum surface temperature is in July. The minimum temperature on the surface is observed in February or January. The greatest temperature gradient was recorded in the upper 2 cm layer. The gradient at the open fen was -2 °C/cm in February and 1.1 °C/cm in October. The peak of formation of the seasonally frozen layer occurs at the end of autumn or in the beginning of winter. The degradation of the seasonally frozen layer was observed both from top and bottom, but the degradation rate from the top is faster.

Object-Based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

NASA Technical Reports Server (NTRS)

Ranson, K. J.; Montesano, P. M.; Nelson, R.

2011-01-01

The circumpolar taiga tundra ecotone was delineated using an image-segmentation-based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 to 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation procedure was used to group pixels representing similar tree cover into polygonal features (segmentation objects) that form the map of the transition zone. Each polygon represents an area much larger than the 500 m MODIS pixel and characterizes the patterns of sparse forest patches on a regional scale. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values from5 to 20%, or (2) mean adjusted TCC values greater than 5% but with a standard deviation less than 5% were used to identify the ecotone. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1 degree longitudinal interval in North America and Eurasia, (2) Landsat-derived Canadian proportion of forest cover for Canada, and (3) with canopy cover estimates extracted from airborne profiling lidar data that transected 1238 of the TCC polygons. The adjusted TCC from MODIS VCF shows, on average, less than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. A comparison of the 1238 TCC polygons with profiling lidar measurements yielded an overall accuracy of 67.7%.

Run-off regime of the small rivers in mountain landscapes (on an example of the mountain "Mongun-taiga

NASA Astrophysics Data System (ADS)

Pryahina, G.; Zelepukina, E.; Guzel, N.

2012-04-01

Hydrological characteristics calculations of the small mountain rivers in the basins with glaciers frequently cause complexity in connection with absence of standard hydrological supervision within remote mountain territories. The unique way of the actual information reception on a water mode of such rivers is field work. The rivers of the mountain Mongun-taiga located on a joint of Altai and Sayan mountains became hydrological researches objects of Russian geographical society complex expeditions in 2010-2011. The Mongun-taiga cluster of international biosphere reserve "Ubsunurskaya hollow" causes heightened interest of researchers — geographers for many years. The original landscape map in scale 1:100000 has been made, hydrological supervision on the rivers East Mugur and ugur, belonging inland basin of Internal Asia are lead. Supervision over the river drain East Mugur runoff were spent in profile of glacier tongue (the freezing area - 22 % (3.2 km2) from the reception basin) and in the closing alignment of the river located on distance of 3,4 km below tongue of glacier. During researches following results have been received. During the ablation period diurnal fluctuations with a strongly shown maximum and minimum of water discharges are typically for the small rivers with considerable share of a glacial food. The run-off maximum from the glacier takes place from 2 to 7 p.m., the run-off minimum is observed early in the morning. High speed of thawed snow running-off from glacier tongue and rather small volume of dynamic stocks water on an ice surface lead to growth of water discharge. In the bottom profile the time of maximum and minimum of water discharge is displaced on the average 2 hours, it depends of the water travel time. Maximum glacial run-off discharge (1.12 m3/s) in the upper profile was registered on July 16 (it was not rain). Volumes of daily runoff in the upper and bottom profiles were 60700-67600 m3 that day. The run-off from nonglacial part of

Tertiary structure-related activity of tick defensin (persulcatusin) in the taiga tick, Ixodes persulcatus.

PubMed

Isogai, Emiko; Isogai, Hiroshi; Okumura, Kazuhiko; Hori, Hatsuhiro; Tsuruta, Hiroki; Kurebayashi, Yoichi

2011-01-01

Defensins are small cysteine-rich cationic proteins found in both vertebrates and invertebrates constituting the front line of host innate immunity. To examine the importance of the tertiary structure of tick defensin in its antimicrobial activity, we synthesized two types of the peptides with tertiary structure or primary one on basis of the information of the sequence in the defensin originated from the taiga tick, Ixodes persulcatus. Chemically synthesized peptides were used to investigate the activity spectrum against Staphylococcus aureus, Borrelia garinii and flora-associated bacteria. Both synthetic peptides showed antimicrobial activity against S. aureus in short-time killing within 1 h, but they do not show the activity against B. garinii, Stenotrophomonas maltophila and Bacillus spp., which were frequently isolated from the midgut of I. persulcatus. The teriary structure brought more potent activity to S. aureus than primary one in short-time killing. We also examined its antimicrobial activity by evaluation of growth inhibition in the presence of the synthetic peptides. Minimum inhibitory concentration (MIC) was ranged from 1.2 to 5.0 μg/ml in tertiary peptide and from 10 to 40 μg/ml in primary peptide, when 10 strains of S. aureus were used. From the curve of cumulative inhibition rates, MIC50 (MIC which half of the strains showed) to S. aureus is about 1.2 μg/ml in the peptide with tertiary structure and about 10 μg/ml in the linear one. Corynebacterium renale is 10 times or more sensitive to tertiary peptide than primary one. In conclusion, the presence of 3 disulfide bridges, which stabilize the molecule and maintain the tertiary structure, is considered to have an effect on their antimicrobial activities against Gram-positive bacteria such as S. aureus.

Additive partitioning of testate amoeba species diversity across habitat hierarchy within the pristine southern taiga landscape (Pechora-Ilych Biosphere Reserve, Russia).

PubMed

Tsyganov, Andrey N; Komarov, Alexander A; Mitchell, Edward A D; Shimano, Satoshi; Smirnova, Olga V; Aleynikov, Alexey A; Mazei, Yuri A

2015-02-01

In order to better understand the distribution patterns of terrestrial eukaryotic microbes and the factors governing them, we studied the diversity partitioning of soil testate amoebae across levels of spatially nested habitat hierarchy in the largest European old-growth dark coniferous forest (Pechora-Ilych Biosphere Reserve; Komi Republic, Russia). The variation in testate amoeba species richness and assemblage structure was analysed in 87 samples from six biotopes in six vegetation types using an additive partitioning procedure and principal component analyses. The 80 taxa recorded represent the highest value of species richness for soil testate amoebae reported for taiga soils so far. Our results indicate that testate amoeba assemblages were highly aggregated at all levels and were mostly controlled by environmental factors rather than dispersal processes. The variation in species diversity of testate amoebae increased from the lowest to the highest hierarchical level. We conclude that, similarly to macroscopic organisms, testate amoeba species richness and community structure are primarily controlled by environmental conditions within the landscape and suggest that metacommunity dynamics of free-living microorganisms are driven by species sorting and/or mass effect processes. Copyright © 2014 Elsevier GmbH. All rights reserved.

First evidence of established populations of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in Sweden.

PubMed

Jaenson, Thomas G T; Värv, Kairi; Fröjdman, Isabella; Jääskeläinen, Anu; Rundgren, Kaj; Versteirt, Veerle; Estrada-Peña, Agustín; Medlock, Jolyon M; Golovljova, Irina

2016-07-01

The tick species Ixodes ricinus and I. persulcatus are of exceptional medical importance in the western and eastern parts, respectively, of the Palaearctic region. In Russia and Finland the range of I. persulcatus has recently increased. In Finland the first records of I. persulcatus are from 2004. The apparent expansion of its range in Finland prompted us to investigate if I. persulcatus also occurs in Sweden. Dog owners and hunters in the coastal areas of northern Sweden provided information about localities where ticks could be present. In May-August 2015 we used the cloth-dragging method in 36 localities potentially harbouring ticks in the Bothnian Bay area, province Norrbotten (NB) of northern Sweden. Further to the south in the provinces Västerbotten (VB) and Uppland (UP) eight localities were similarly investigated. Ixodes persulcatus was detected in 9 of 36 field localities in the Bothnian Bay area. Nymphs, adult males and adult females (n = 46 ticks) of I. persulcatus were present mainly in Alnus incana - Sorbus aucuparia - Picea abies - Pinus sylvestris vegetation communities on islands in the Bothnian Bay. Some of these I. persulcatus populations seem to be the most northerly populations so far recorded of this species. Dog owners asserted that their dogs became tick-infested on these islands for the first time 7-8 years ago. Moose (Alces alces), hares (Lepus timidus), domestic dogs (Canis lupus familiaris) and ground-feeding birds are the most likely carriers dispersing I. persulcatus in this area. All ticks (n = 124) from the more southern provinces of VB and UP were identified as I. ricinus. The geographical range of the taiga tick has recently expanded into northern Sweden. Increased information about prophylactic, anti-tick measures should be directed to people living in or visiting the coastal areas and islands of the Baltic Bay.

Transformation of peat horizon in swampy southern taiga forests under the impact of surface drainage

NASA Astrophysics Data System (ADS)

Vomperskii, S. E.; Vomperskaya, M. I.; Glukhova, T. V.; Valyaeva, N. A.

2017-10-01

The results of stationary studies of swampy southern taiga forests in Yaroslavl oblast are presented. Estimates of changes in the thickness of peat horizon in peat podzolic gley soils (Folic Albeluvisols) of forests subjected to clearcutting and further intensive forest management in the past 30 years are given. The mean annual precipitation in these three decades has been 116 mm higher than that during the preceding three decades, which has led to a progressive swamping of spruce stands on heavy loamy soils within virtually flat (with slopes up to 0.0035) surfaces and an increase in the organic matter storage in the peat soil horizon with the mean annual rate of 22-68 g/m2. On more pronounced slopes (0.0050), no swamping of spruce and pine stands growing on sandy soils has taken place. Surface drainage of swampy forests through the network of shallow ditches has led to an increase in the productivity of forests; in most cases, the pool of organic matter in the peat horizon has been decreasing with the mean annual rate of 32-46 g/m2. This attests to the reversible character of swamping in dependence on climatic fluctuations and forestry measures. Changes in the carbon pool of swampy soils during short (several years) excessively wet or excessively dry periods may be significantly higher than the average values for 30 years in different types of forests. This allows us to consider swampy forests as the source of significant errors in the estimates of the current contribution of biota to the carbon cycle, because their role (as well as the role of other forests) is assessed without taking into account considerable short-term fluctuations in the carbon pool of their soils.

[Influence of meteorological factors on the activity of the adult taiga tick (Ixodes persulcatus Sch., Ixodinae) in St. Petersburg and its environs].

PubMed

Osipova, T N; Grigoryeva, L A; Samoylova, E P; Shapar, A O; Bychkova, E M

2017-01-01

The article deals with influence of meteorolical factors on the activity of the taiga tick Ixodes persulvatus Sch. in St. Petersburg and its environs. The results of correlation analysis of meteorological data (21 index) and data ticks collected in 1980-2012 allowed determining linear dependence between 11 meteorological indices an average amount of ticks. Factor analysis reduced dimentionality down to 3 indices: sum of temperatures higher than +5.0 °C, sum of precipitation higher than 5 mm per year, and Selyaninov hydrothermal coefficient. It was demonstrated that, at the background of the general tendency for the decrease of the average number of active ticks in the studied territories, correlation between the amount of ticks and meteorological indices can significantly vary as in the correlation density, so in the character and in dependence of microclimatic features of the collecting site. When variability of the mean abundance of ticks during years of investigation is low, the methods of collecting can significantly affect the results of the statistical analysis. This fact must be taken in consideration during prognosis of both dates of the beginning of epidemiological season and its intensity.

[Study on the infection of taiga ticks with Borrelia in the territory of Novosibirsk Scientific Center SB PAS].

PubMed

Borgoiakov, V Iu; Fomenko, N V; Panov, V V; Chikova, E D

2010-01-01

In our study, Borrelia were revealed in the taiga ticks Ixodes persulcatus collected on vegetation by flagging, as well as in the ticks removed from the people who asked for help in the vaccination center located in the Novosibirsk Scientific Center of the Siberian Branch of Russian Academy of Science (NS SB RAS). By the isolation of Borrelia on BSK-H medum, the occurrence of B. garinii, B. afzelii, and B. miyamotoi was established in the territory of NSC. B. miyamotoi isolates were unstable and lost their ability to growth in later passages. DNA of the same three species of Borrelia was detected by PCR in the samples of ticks, both collected on vegetation by flagging and removed from humans. DNA of B. garinii was recorded most often; DNA of B. afzelii was less frequent; and the least number of positive samples was shown for B. miyamotoi. In the ticks collected on vegetation by flagging, DNA of B. garinii was found in 38.6%, B. afzelii in 9.9%, and B. miyamoboi in 3.9% of samples. In the ticks removed from people, number of positive samples was lesser; so, DNA of B. garinii was detected in 24.2%, B. afzelii in 6.9%, and B. miyamotoi in 5.6% of samples. Mixed infection with two Borrelia species was recorded, and DNA of B. mivamnotoi more often detected simultaneously with DNA of B. garinii.

Spatial and temporal dimensions of fire activity in the fire-prone eastern Canadian taiga.

PubMed

Erni, Sandy; Arseneault, Dominique; Parisien, Marc-André; Bégin, Yves

2017-03-01

The forest age mosaic is a fundamental attribute of the North American boreal forest. Given that fires are generally lethal to trees, the time since last fire largely determines the composition and structure of forest stands and landscapes. Although the spatiotemporal dynamics of such mosaics has long been assumed to be random under the overwhelming influence of severe fire weather, no long-term reconstruction of mosaic dynamics has been performed from direct field evidence. In this study, we use fire length as a proxy for fire extent across the fire-prone eastern Canadian taiga and systematically reconstruct the spatiotemporal variability of fire extent and fire intervals, as well as the resulting forest age along a 340-km transect for the 1840-2013 time period. Our results indicate an extremely active fire regime over the last two centuries, with an overall burn rate of 2.1% of the land area yr -1 , mainly triggered by seasonal anomalies of high temperature and severe drought. However, the rejuvenation of the age mosaic was strongly patterned in space and time due to the intrinsically lower burn rates in wetland-dominated areas and, more importantly, to the much-reduced likelihood of burning of stands up to 50 years postfire. An extremely high burn rate of ~5% yr -1 would have characterized our study region during the last century in the absence of such fuel age effect. Although recent burn rates and fire sizes are within their range of variability of the last 175 years, a particularly severe weather event allowed a 2013 fire to spread across a large fire refuge, thus shifting the abundance of mature and old forest to a historic low. These results provide reference conditions to evaluate the significance and predict the spatiotemporal dynamics and impacts of the currently strengthening fire activity in the North American boreal forest. © 2016 John Wiley & Sons Ltd.

Acid-base buffering of soils in transitional and transitional-accumulative positions of undisturbed southern-taiga landscapes

NASA Astrophysics Data System (ADS)

Rusakova, E. S.; Ishkova, I. V.; Tolpeshta, I. I.; Sokolova, T. A.

2012-05-01

The method of continuous potentiometric titration (CPT) of soil water suspensions was used to evaluate the acid-base buffering of samples from the major genetic horizons of podzolic soils on a slope and soddy gley soils on the adjacent floodplain of a rivulet. In the soils of the slope, the buffering to acid upon titration from the pH of the initial titration point (ITP) to pH 3 in all the horizons was 1.5-2.0 times lower than that in the podzolic soils of the leveled interfluve, which could be due to the active leaching of exchangeable bases and oxalate-soluble aluminum and iron compounds with the later soil flows. In the soddy gley soils, the buffering to acid in the mineral horizons was 2-10 times higher than that in the podzolic soils. A direct dependence of the soil buffering to acid on the total content of exchangeable bases and on the content of oxalate-soluble aluminum compounds was found. A direct dependence of the buffering to basic upon titration from the ITP to pH 10 on the contents of the oxalate-soluble aluminum and organic matter was observed in the mineral horizons of all the studied soils. The soil treatment with Tamm's reagent resulted in the decrease of the buffering to acid in the soddy gley soils of the floodplain, as well as in the decrease of the buffering to basic in the soils on the slopes and in the soddy gley soils. It was also found that the redistribution of the mobile aluminum compounds between the eluvial, transitional, and transitional-accumulative positions in the undisturbed southern taiga landscapes leads to significant spatial differentiation of the acid-base buffering of the mineral soil horizons with a considerable increase in the buffer capacity of the soils within the transitional-accumulative terrain positions.

Influence of water table on carbon dioxide, carbon monoxide, and methane fluxes from taiga bog microcosms

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

Funk, D.W.; Pullmann, E.R.; Peterson, K.M.

1994-09-01

Hydrological changes, particularly alterations in water table level, may largely overshadow the more direct effects of global temperature increase upon carbon cycling in arctic and subarctic wetlands. Frozen cores (n=40) of intact soils and vegetation were collected from a bog near Fairbanks, Alaska, and fluxes of CO{sub 2}, CH{sub 4}, and Co in response to water table variation were studied under controlled conditions in the Duke University phytotron. Core microcosms thawed to a 20-cm depth over 30 days under a 20 hour photoperiod with a day/night temperature regime of 20/10{degrees}C. After 30 days the water table in 20 microcosms wasmore » decreased from the soil surface to -15 cm and maintained at the soil surface in 20 control cores. Outward fluxes of CO{sub 2} (9-16 g m{sup -2}d{sup -1}) and CO (3-4 mg m{sup -2}d{sup -1}) were greatest during early thaw and decreased to near zero for both gases before the water table treatment started. Lower water table tripled CO{sub 2} flux to the atmosphere when compared with control cores. Carbon monoxide was emitted at low rates from high water table cores and consumed by low water table cores. Methane fluxes were low (<1 mg m{sup -2}d{sup -1}) in all cores during thaw. High water table cores increased CH{sub 4} flux to 8-9 mg m{sup -2}d{sup -1} over 70 days and remained high relative to the low water table cores (<0.74 mg m{sup -2}d{sup -1}). Although drying of wetland taiga soils may decrease CH{sub 4} emissions to the atmosphere, the associated increase in CO{sub 2} due to aerobic respiration will likely increase the global warming potential of gas emissions from these soils. 43 refs., 4 figs.« less

Diagnosis of the hydrology of a small Arctic basin at the tundra-taiga transition using a physically based hydrological model

NASA Astrophysics Data System (ADS)

Krogh, Sebastian A.; Pomeroy, John W.; Marsh, Philip

2017-07-01

A better understanding of cold regions hydrological processes and regimes in transitional environments is critical for predicting future Arctic freshwater fluxes under climate and vegetation change. A physically based hydrological model using the Cold Regions Hydrological Model platform was created for a small Arctic basin in the tundra-taiga transition region. The model represents snow redistribution and sublimation by wind and vegetation, snowmelt energy budget, evapotranspiration, subsurface flow through organic terrain, infiltration to frozen soils, freezing and thawing of soils, permafrost and streamflow routing. The model was used to reconstruct the basin water cycle over 28 years to understand and quantify the mass fluxes controlling its hydrological regime. Model structure and parameters were set from the current understanding of Arctic hydrology, remote sensing, field research in the basin and region, and calibration against streamflow observations. Calibration was restricted to subsurface hydraulic and storage parameters. Multi-objective evaluation of the model using observed streamflow, snow accumulation and ground freeze/thaw state showed adequate simulation. Significant spatial variability in the winter mass fluxes was found between tundra, shrubs and forested sites, particularly due to the substantial blowing snow redistribution and sublimation from the wind-swept upper basin, as well as sublimation of canopy intercepted snow from the forest (about 17% of snowfall). At the basin scale, the model showed that evapotranspiration is the largest loss of water (47%), followed by streamflow (39%) and sublimation (14%). The models streamflow performance sensitivity to a set of parameter was analysed, as well as the mean annual mass balance uncertainty associated with these parameters.

Hydrology and Climatology of the Caribou-Poker Creeks Research Watershed, Alaska,

DTIC Science & Technology

1982-10-01

system the watershed falls within the Inter- dense brush of willow, alder and dwarf birch in ior Alaska Forest ( Taiga ) designation. open forests near...and C.T. Cushwina (1973) Research stream flow characteristics in the discontinuous opportunities and needs in the Taiga of Alaska. permafrost zone of...edition. taiga research watershed. Institute of Water Re- linkenson, W.M. nB. Lotspeich and lW. Mueller sources, University of Alaska, Fairbanks, Alaska

Variability in methane emissions from West Siberia's shallow boreal lakes on a regional scale and its environmental controls

NASA Astrophysics Data System (ADS)

Sabrekov, Aleksandr F.; Runkle, Benjamin R. K.; Glagolev, Mikhail V.; Terentieva, Irina E.; Stepanenko, Victor M.; Kotsyurbenko, Oleg R.; Maksyutov, Shamil S.; Pokrovsky, Oleg S.

2017-08-01

Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatiotemporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July-August 2014 within the West Siberian middle and southern taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m-2 h-1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m-2 h-1 for southern taiga lakes, respectively. Pronounced flux variability was found during measurements on individual lakes, between individual lakes and between zones. To analyze these differences and the influences of environmental controls, we developed a new dynamic process-based model. It shows good performance with emission rates from the southern taiga lakes and poor performance for individual lakes in the middle taiga region. The model shows that, in addition to well-known controls such as temperature, pH and lake depth, there are significant variations in the maximal methane production potential between these climatic zones. In addition, the model shows that variations in gas-filled pore space in lake sediments are capable of controlling the total methane emissions from individual lakes. The CH4 emissions exhibited distinct zonal differences not only in absolute values but also in their probability density functions: the middle taiga lake fluxes were best described by a lognormal distribution while the southern taiga lakes followed a power-law distribution. The latter suggests applicability of self-organized criticality theory for methane emissions from the southern taiga zone, which could help to explain the strong variability within individual lakes.

Specific features of the development of soils of hydromorphic ecosystems in the northern taiga of Western Siberia under conditions of cryogenesis

NASA Astrophysics Data System (ADS)

Matyshak, G. V.; Bogatyrev, L. G.; Goncharova, O. Yu.; Bobrik, A. A.

2017-10-01

Differently directed and heterochronous cryogenic processes have contributed to the contrasting soil cover patterns and spatial heterogeneity of the properties of soils in hydromorphic ecosystems of the discontinuous permafrost zone of the northern taiga in Western Siberia. Frost heave and permafrost thawing within ecosystems of highmoor bogs have led to the development of specific cryogenic landforms, such as flat-topped and large peat mounds. A set of cryogenic soils is developed in these ecosystems; it includes different variants of cryozems, gleyzems (Cryosols), and peat soils (Histosols). The distribution of these soil types is controlled by the local topography and thawing depth, other factors being insignificant. Alternation of peat horizons of different types and ages, whirl-like patterns of horizon boundaries, considerable variations in the thickness of soil horizons, and inversions of soil horizons under the impact of frost cracking, frost heave, and cryoturbation are typical of the considered soils. Thawing depth is the most significant factor affecting the thickness of organic horizons, the soil pH, and the degree of decomposition of peat. As a result of the upward movement of bog ecosystems under the impact of frost heave, peat soils are subjected to considerable transformation: peat horizons undergo mineralization, and the thickness of organic horizons decreases; in some cases, eluvial-illuvial differentiation of the mineral horizons takes place, and peat podzols are developed. However, the opposite process of the return of the soils to the bog stage of pedogenesis with peat accumulation may take place in any time in the case of activation of thermokarst processes.

SMALL MAMMAL BIOCLIMATE STUDIES IN NORTHERN REGIONS

DTIC Science & Technology

northern regions. Two major divisions are established - the tundra (arctic treeless region) and the taiga (subarctic spruce forest). Further subdivisions...of taiga small mammals are analyzed. Points of potential value to the Air Force are drawn from studies on the importance of topographical

Permafrost thaw and fire history: implications of boreal tree cover changes on land surface properties and turbulent energy fluxes in the Taiga Plains, Canada

NASA Astrophysics Data System (ADS)

Sonnentag, Oliver; Helbig, Manuel; Payette, Fanny; Wischnewski, Karoline; Kljun, Natascha; Chasmer, Laura; Pappas, Christoforos; Detto, Matteo; Baltzer, Jennifer; Quinton, William; Marsh, Philip

2016-04-01

Given their large areal coverage, high carbon densities, and unique land surface properties and disturbance regimes (e.g., wildfires), the world's boreal forests are integral components of the global and regional climate systems. A large portion of boreal forests contain permafrost, i.e., perennially cryotic ground. In the Taiga Plains ecozone in northwestern Canada, the northernmost boreal forests grow on cold (<-1.5 °C) and thick (>100 m) continuous permafrost (>90 % in areal extent). More southerly boreal forests occur in areas with discontinuous (>50 - 90 % in areal extent), sporadic (>10 - 50 % in areal extent) and isolated permafrost (<10 % in areal extent). Using annual MODIS Percent Tree Cover (PTC) data from the MOD44B product in combination with spatial information on fire history, and permafrost and drainage characteristics, we show that in low-lying, poorly-drained areas along the southern fringe of permafrost, thawing induces widespread decreases in PTC and dominates over PTC increases due to post-fire regrowth. In contrast, PTC appears to be slightly increasing in the central and northern Taiga Plains with more stable discontinuous and continuous permafrost, respectively. While these increases are partly explained by post-fire regrowth, more favourable growing conditions may also contribute to increasing PTC. To better understand the implications of permafrost thaw on land surface properties (e.g., aerodynamic conductance for heat [ga] and surface conductance for water vapour [gs]), and the turbulent fluxes of latent (LE) and sensible heat (H) along the southern fringe of permafrost, we examined nested eddy covariance flux measurements made at two nearby locations at Scotty Creek (61°18' N; 121°18' W) starting May 2013. The low-lying, poorly-drained southern portion of this 152 km2-watershed contains rapidly thawing sporadic permafrost resulting in a highly dynamic mosaic dominated by decreasing forested permafrost peat plateaus, and increasing

The dendroclimatic proxies from the northern Quebec taiga in the PAGES 2K network: recent advances and future developments.

NASA Astrophysics Data System (ADS)

Gennaretti, Fabio; Naulier, Maud; Arseneault, Dominique; Savard, Martine; Bégin, Christian; Boucher, Etienne; Bégin, Yves; Guiot, Joël

2016-04-01

Northeastern North America was historically underrepresented in the network of climate proxies used for climate reconstructions over the last two millennia. Indeed, in North America most high-resolution climate proxies are long tree-ring chronologies but, in Northeastern North America, these chronologies are highly challenging due to short tree longevity, high frequency and severity of wildfires and remoteness of many areas. Here, we will present the efforts accomplished during the last decade by our team in developing millennial-long tree-ring chronologies in the northern Quebec taiga. We sampled black spruce [Picea mariana (Mill.) B.S.P] subfossil tree remains naturally fallen in the littoral zone of six lakes to build six site-specific ring-width chronologies as well as two chronologies of stable isotope ratios (δ18O and δ13C in tree-ring cellulose). These chronologies, which are now included in the PAGES 2K network, were independently used to reconstruct summer temperature variations showing a well-expressed Medieval Climate Anomaly and the impact of volcanic and solar forcings at regional scale. We will also discuss non-climatic influences on these chronologies (i.e. wildfires and sampling height inconsistency), as well as the ongoing effort to extend the reconstructions in time to cover the last 2500 years. Finally, a new European funded project called MAIDEN-SPRUCE will be introduced. Within MAIDEN-SPRUCE, we will use a data-model approach to improve our understanding of the links between forests and climate over the last millennium. More specifically, we will adapt the process-based ecophysiological model MAIDENiso to investigate factors influencing the growth and underlying biogeochemical processes of black spruce. One of our objectives is to provide the first multi-proxy (ring widths and δ18O and δ13C in tree-ring cellulose) regional climate reconstruction in Eastern North America over the last millennium taking into account mechanistic rules

Soviet Developments in Weather Modification, Climate Modification, and Climatology

DTIC Science & Technology

1975-09-01

48-55. n 3. Mikhaylov, Yu. P. The environmental impact on the taiga geosystems of the diversion of northern river runoff. (VI th...expanded session of the Scientific Council of the Siberian Branch of the USSR Academy of Sciences on the complex reclamation of taiga territories

The Russians are coming - aren't they? Siberian moth in European forests

Treesearch

Yuri N. Baranchikov; Vladimir M. Pet' ko; Vladimir L. Ponomarev

2007-01-01

Dendrolimus superans sibiricus Tschtv. (Lepidoptera: Lasiocampidae) is the most destructive defoliator of the coniferous taiga forest in Siberia and the Russian Far East. Outbreaks of this pest species are the primary biological factor influencing change in forest cover in the southern taiga subzone with enormous ecological and social consequences (...

The Petsamo-Kirkenes Operation: Soviet Breakthrough and Pursuit in the Arctic, October 1944 (Leavenworth Papers, Number 17)

DTIC Science & Technology

1989-09-01

Roschmann , "Small Unit Tactics, Combats in Taiga and Tundra," Foreign Military Studies no. MS P-060m (Historical Division, U.S. Army, Europe, 1952), 148...Brockelmann, Klaus, and Hans Roschmann . "Small Unit Tactics, Combats in Taiga and Tundra." Foreign Military Studies no. MS P-060m. Historical Division

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region (Version 2.0)

DTIC Science & Technology

2007-09-01

07-24 102 Viereck, L. A., K. Van Cleve, and C. T. Dyrness. 1986. Forest ecosystem distribution in the Taiga environment, Chapter 3. In Forest...ecosystems in the Alaska Taiga : A synthesis of structure and function. ed. K. Van Cleve, F. S. Chapin III, P. W. Flanagan, L. A. Viereck, and C. T

Radiocarbon ages of terrestrial gastropods extend duration of ice-free conditions at the Two Creeks forest bed, Wisconsin, USA

USGS Publications Warehouse

Rech, Jason A.; Nekola, Jeffrey C.; Pigati, Jeffrey S.

2012-01-01

Analysis of terrestrial gastropods that underlie the late Pleistocene Two Creeks forest bed (~ 13,800–13,500 cal yr BP) in eastern Wisconsin, USA provides evidence for a mixed tundra-taiga environment prior to formation of the taiga forest bed. Ten new AMS 14C analyses on terrestrial gastropod shells indicate the mixed tundra-taiga environment persisted from ~ 14,500 to 13,900 cal yr BP. The Twocreekan climatic substage, representing ice-free conditions on the shore of Lake Michigan, therefore began near the onset of peak warming conditions during the Bølling–Allerød interstadial and lasted ~ 1000 yr, nearly 600 yr longer than previously thought. These results provide important data for understanding the response of continental ice sheets to global climate forcing and demonstrate the potential of using terrestrial gastropod fossils for both environmental reconstruction and age control in late Quaternary sediments.

[Ecological characteristics and distribution of the mosquito Aedes communis (De Geer, 1776) in the Northwestern part of European Russia].

PubMed

Medvedev, S G; Aĭbulatiov, S V; Paniukova, E V

2010-01-01

According to recent data, Aedes communis is a polytopic species inhabiting both zonal and intrazonal biotopes. It has a wide Holarctic nemoral-tundra-steppe range, which can be characterized as European-Asiatic-North-American. In the North-West of the European part of Russia, A. communis occurs in early spring and summer, being a monocyclic species. It is distributed everywhere, both in zones of tundra and forest-tundra and in all taiga subzones. Aedes communis is a psychrophilic species, but attacks of its females were recorded under the temperatures from 2.5 to 28 degrees C. The species occurs in biotopes of different types, but in the taiga zone it is distributed mainly in swampy coniferous forests and, particularly, in fir-woods where its quantity is steadily high, amounting to 70% and more of the mosquito females collections. When fir-woods are cut down, A. communis develops in the reservoirs situated in the small-leaved forests forming in taiga after deforestation.

Dynamics of Soil Properties and Plant Composition during Postagrogenic Evolution in Different Bioclimatic Zones

NASA Astrophysics Data System (ADS)

Telesnina, V. M.; Kurganova, I. N.; Lopes de Gerenyu, V. O.; Ovsepyan, L. A.; Lichko, V. I.; Ermolaev, A. M.; Mirin, D. M.

2017-12-01

The postagrogenic dynamics of acidity and some parameters of humus status have been studied in relation to the restoration of zonal vegetation in southern taiga (podzolic and soddy-podzolic soils ( Retisols)), coniferous-broadleaved (subtaiga) forest (gray forest soil ( Luvic Phaeozem)), and forest-steppe (gray forest soil ( Haplic Phaeozem)) subzones. The most significant transformation of the studied properties of soils under changing vegetation has been revealed for poor sandy soils of southern taiga. The degree of changes in the content and stocks of organic carbon, the enrichment of humus in nitrogen, and acidity in the 0- to 20-cm soil layer during the postagrogenic evolution decreases from north to south. The adequate reflection of soil physicochemical properties in changes of plant cover is determined by the climatic zone and the land use pattern. A correlation between the changes in the soil acidity and the portion of acidophilic species in the plant cover is revealed for the southern taiga subzone. A positive relationship is found between the content of organic carbon and the share of species preferring humus-rich soils in the forest-steppe zone.

[Landscape and zonal distribution of bloodsucking mosquitoes and horse flies (Diptera: Culicidae, Tabanidae) in the northeastern Russian Plain].

PubMed

Pestov, S V; Paniukova, E V

2013-01-01

The data on the distribution of 34 species of bloodsucking mosquitoes and on 42 horsefly species of the fauna of the northeastern Russian Plain are given. The analysis of the landscape and zonal changes in species diversity and their abundance was performed. Species diversity of these families increased northwards. Two borders of the fauna's depletion were discovered: at the border between the middle and northern taiga subzones (mosquitoes and horseflies) and at the border between the northernmost taiga subzone and the forest-tundra zone (horseflies only). The northern and southern boundaries of species ranges in the region are identified.

Long-term measurements of aerosols and carbon monoxide at the ZOTTO tall tower to characterize polluted and pristine air in the Siberian Taiga

NASA Astrophysics Data System (ADS)

Chi, X.; Winderlich, J.; Mayer, J.-C.; Panov, A. V.; Heimann, M.; Birmili, W.; Heintzenberg, J.; Cheng, Y.; Andreae, M. O.

2013-07-01

Siberia is one of few background regions in the Northern Hemisphere where the atmosphere may sometimes approach pristine conditions. We present the time series of aerosol and carbon monoxide (CO) measurements between September~2006 and December 2010 at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 90° E). We investigate the seasonal, weekly and diurnal variations of aerosol properties (including absorption and scattering coefficients and derived parameters, like equivalent black carbon (BCe), Ångström exponent, single scattering albedo, and backscattering ratio) and the CO mixing ratios. Criteria were established to distinguish polluted and near-pristine air masses and characterize them separately. Depending on the season, 15-47% of the sampling time at ZOTTO was representative of a clean atmosphere. The summer pristine data indicates that primary biogenic and/or secondary organic aerosol formation are quite strong particle sources in the Siberian Taiga. The summer seasons 2007-2008 are dominated by an Aitken mode of 80 nm size, whereas the summer 2009 with prevailing easterly winds produced aerosols in the accumulation mode around 200 nm size. We found these differences mainly related to air temperature, in parallel with production rates of biogenic volatile organic compounds (VOC). In winter, the footprint and aerosol size distribution (with a peak at 160 nm) of the clean background air are characteristic for aged aerosols from anthropogenic sources at great distances from ZOTTO and diluted biofuel burning emissions from heating. The wintertime polluted air originates from the large cities to the south and southwest of the site; these aerosols have a dominant mode around 100 nm, and the Δ BCe/Δ CO ratio of 7-11 ng m-3 ppb-1 suggests dominant contributions from coal and biofuel burning for heating. During summer, anthropogenic emissions are the dominant contributor to the pollution aerosols at ZOTTO, while only 12% of the polluted

Long-term measurements of aerosol and carbon monoxide at the ZOTTO tall tower to characterize polluted and pristine air in the Siberian taiga

NASA Astrophysics Data System (ADS)

Chi, X.; Winderlich, J.; Mayer, J.-C.; Panov, A. V.; Heimann, M.; Birmili, W.; Heintzenberg, J.; Cheng, Y.; Andreae, M. O.

2013-12-01

Siberia is one of few continental regions in the Northern Hemisphere where the atmosphere may sometimes approach pristine background conditions. We present the time series of aerosol and carbon monoxide (CO) measurements between September 2006 and December 2011 at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E). We investigate the seasonal, weekly and diurnal variations of aerosol properties (including absorption and scattering coefficients and derived parameters, such as equivalent black carbon (BCe), Ångström exponent, single scattering albedo, and backscattering ratio) and the CO mixing ratios. Criteria were established to distinguish polluted from near-pristine air masses, providing quantitative characteristics for each type. Depending on the season, 23-36% of the sampling time at ZOTTO was found to be representative of a clean atmosphere. The summer pristine data indicate that primary biogenic and secondary organic aerosol formation are quite strong particle sources in the Siberian taiga. The summer seasons 2007-2008 were dominated by an Aitken mode around 80 nm size, whereas the summer 2009 with prevailing easterly winds produced particles in the accumulation mode around 200 nm size. We found these differences to be mainly related to air temperature, through its effect on the production rates of biogenic volatile organic compounds (VOC) precursor gases. In winter, the particle size distribution peaked at 160 nm, and the footprint of clean background air was characteristic for aged particles from anthropogenic sources at great distances from ZOTTO and diluted biofuel burning emissions from domestic heating. The wintertime polluted air originates mainly from large cities south and southwest of the site; these particles have a dominant mode around 100 nm, and the ΔBCe / ΔCO ratio of 7-11 ng m-3 ppb-1 suggests dominant contributions from coal and biofuel burning for heating. During summer, anthropogenic emissions are the dominant

Influence of increasing active-layer depth and continued permafrost degradation on carbon, water and energy fluxes over two forested permafrost landscapes in the Taiga Plains, NWT, Canada

NASA Astrophysics Data System (ADS)

Sonnentag, O.; Baltzer, J.; Chasmer, L. E.; Detto, M.; Marsh, P.; Quinton, W. L.

2012-12-01

Recent research suggests an increase in active-layer depth (ALD) in the continuous permafrost zone and degradation of the discontinuous permafrost zone into seasonally frozen. Increasing ALD and continued permafrost degradation will have far-reaching consequences for northern ecosystems including altered regional hydrology and the exposure of additional soil organic carbon (C) to microbial decomposition. These changes might cause positive or negative net feedbacks to the climate system by altering important land surface properties and/or by releasing stored soil organic C to the atmosphere as CO2 and/or CH4. Knowledge gaps exist regarding the links between increasing ALD and/or permafrost degradation, regional hydrology, vegetation composition and structure, land surface properties, and CO2 and CH4 sink-source strengths. The goal of our interdisciplinary project is to shed light on these links by providing a mechanistic understanding of permafrost-thawing consequences for hydrological, ecophysiological and biogeochemical processes at two forested permafrost landscapes in the Taiga Plains, NWT, Canada: Scotty Creek and Havikpak Creek in the discontinuous and in the continuous permafrost zones, respectively (Fig.). The sites will be equipped with identical sets of instrumentation (start: 2013), to measure landscape-scale net exchanges of CO2, CH4, water and energy with the eddy covariance technique. These measurements will be complemented by repeated surveys of surface and frost table topography and vegetation, by land cover-type specific fluxes of CO2 and CH4 measured with a static chamber technique, and by remote sensing-based footprint analysis. With this research we will address the following questions: What is the net effect of permafrost thawing-induced biophysical and biogeochemical feedbacks to the climate system? How do these two different types of feedback differ between the discontinuous and continuous permafrost zones? Is the decrease (increase) in net CO

How and why is aquatic quality changing at Nahanni National Park Reserve, NWT, Canada?

PubMed

Halliwell, Douglas R; Catto, Steve

2003-01-01

Nahanni National Park Reserve is located at southwestern NWT-Yukon border. One of the first UNESCO World Heritage sites, Nahanni lies within Taiga Cordillera and Taiga Shield Ecozones. Base and precious metal mining occurred upstream of Nahanni prior to park establishment. Nahanni waters, sediments, fish, and caribou have naturally elevated metals levels. Baseline water, sediment and fish tissue quality data were collected and analyzed throughout Nahanni during 1988-91 and 1992-97. These two programs characterized how aquatic quality variables are naturally varying in space and time, affected by geology, stream flow, seasonality, and extreme meteorological and geological events. Possible anthropogenic causes of aquatic quality change were examined. Measured values were compared to existing Guidelines and site-specific objectives were established.

Missing saiga on the taiga.

PubMed

Kuhn, Tyler S; Mooers, Arne Ø

2010-11-01

Conservation biologists understand that linking demographic histories of species at risk with causal biotic and abiotic events should help us predict the effects of ongoing biotic and abiotic change. In parallel, researchers have started to use ancient genetic information (aDNA) to explore the demographic histories of a number of species present in the Pleistocene fossil record (see, e.g. Shapiro et al. 2004). However, aDNA studies have primarily focused on identifying long-term population trends, linked to climate variability and the role of early human activity. Population trends over more recent time, e.g. during the Holocene, have been poorly explored, partly owing to analytical limitations. In this issue, Campos et al. (2010a) highlight the potential of aDNA to investigate demographic patterns over such recent time periods for the compelling and endangered saiga antelope Saiga tatarica (Fig. 1). The time may come when past and current demography can be combined to produce a seamless record. [Figure: see text]. © 2010 Blackwell Publishing Ltd.

Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese

USGS Publications Warehouse

Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.

2013-01-01

We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during

Water relations and photosynthetic performance in Larix sibirica growing in the forest-steppe ecotone of northern Mongolia.

PubMed

Dulamsuren, Choimaa; Hauck, Markus; Bader, Martin; Osokhjargal, Dalaikhuu; Oyungerel, Shagjjav; Nyambayar, Suran; Runge, Michael; Leuschner, Christoph

2009-01-01

Shoot water relations were studied in Siberian larch (Larix sibirica Ledeb.) trees growing at the borderline between taiga and steppe in northern Mongolia. Larix sibirica is the main tree species in these forests covering 80% of Mongolia's forested area. Minimum shoot water potentials (Psi(m)) close to the point of zero turgor (Psi(0)) repeatedly recorded throughout the growing season suggest that the water relations in L. sibirica were often critical. The Psi(m) varied in close relation to the atmospheric vapor pressure deficit, whereas Psi(0) was correlated with monthly precipitation. Young larch trees growing at the forest line to the steppe were more susceptible to drought than mature trees at the same sites. Furthermore, isolated trees growing on the steppe exhibited lower Psi(m) and recovered to a lower degree from drought overnight than the trees at the forest line. Indications of drought stress in L. sibirica were obtained in two study areas in Mongolia's forest-steppe ecotone: one in the mountain taiga of the western Khentey in northernmost Mongolia, the other in the forest-steppe at the southern distribution limit of L. sibirica on Mt. Bogd Uul, southern Khentey. Larix sibirica growing in riverine taiga with contact to the groundwater table was better water-supplied than the larch trees growing at the forest line to the steppe. Larch trees from the interior of light taiga forests on north-facing slopes, however, exhibited more critical water relations than the trees at the forest line. Frequent drought stress in mature trees and even more in young larch trees at the forest-steppe borderline suggests that L. sibirica does not have the potential to encroach on the steppe under the present climate, except in a sequence of exceptionally moist and cool years. A regression of the present borderline between forest and steppe is likely to occur, as average temperatures are increasing everywhere and precipitation is decreasing regionally in Mongolia's taiga forest

A methane flux transect along the trans-Alaska pipeline haul road

NASA Technical Reports Server (NTRS)

Whalen, S. C.; Reeburgh, W. S.

1990-01-01

This paper reports and analyzes methane flux measurements made during the summer of 1987 at 10 km intervals along a north-south direction from Prudhoe Bay to the Arctic Circle in Alaska. Mean CH4 flux from the arctic tundra was 52 mg/sq m/d while that from high-latitude taiga was 11 mg/sq m/d. Fluxes in mg/sq m/d for various plant communities were: wet tundra, 90; low brush-muskeg bog, 45; moist tundra, 31; freshwater ponds, 21; spruce forest, 4.6; and alpine tundra, 0.6. Annual CH4 emission from global tundra and taiga environments is estimated at 38 Tg and 15 Tg, respectively. This is about 46 percent of the wetland emission term of 10 percent of the global atmospheric input.

Tundra biome research in Alaska: the structure and function of cold-dominated ecosystems

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

Brown, J.; West, G.C.

1970-11-01

The objective of the Tundra Biome Program is to acquire a basic understanding of tundra, both alpine and arctic, and taiga. Collectively these are referred to as the cold-dominated ecosystems. The program's broad objectives are threefold: To develop a predictive understanding of how the wet arctic tundra ecosystem operates, particularly as exemplified in the Barrow, Alaska, area; to obtain the necessary data base from the variety of cold-dominated ecosystem types represented in the United States, so that their behavior can be modeled and simulated, and the results compared with similar studies underway in other circumpolar countries; to bring basic environmentalmore » knowledge to bear on problems of degradation, maintenance, and restoration of the temperature-sensitive and cold-dominated tundra/taiga ecosystems. (GRA)« less

Environmental and societal consequences of a possible CO/sub 2/-induced climate change. Volume II, Part 14. Research needed to determine the present carbon balance of northern ecosystems and the potential effect of carbon-dioxide-induced climate change

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

Miller, P.C.

1982-10-01

Given the potential significance of northern ecosystems to the global carbon budget it is critical to estimate the current carbon balance of these ecosystems as precisely as possible, to improve estimates of the future carbon balance if world climates change, and to assess the range of certainty associated with these estimates. As a first step toward quantifying some of the potential changes, a workshop with tundra and taiga ecologists and soil scientists was held in San Diego in March 1980. The first part of this report summarizes the conclusions of this workshop with regard to the estimate of the currentmore » areal extent and carbon content of the circumpolar arctic and the taiga, current rates of carbon accumulation in the peat in the arctic and the taiga, and predicted future carbon accumulation rates based on the present understanding of controlling processes and on the understanding of past climates and vegetation. This report presents a finer resolution of areal extents, standing crops, and production rates than was possible previously because of recent syntheses of data from the International Biological Program and current studies in the northern ecosystems, some of which have not yet been published. This recent information changes most of the earlier estimates of carbon content and affects predictions of the effect of climate change. The second part of this report outlines research needed to fill major gaps in the understanding of the role of northern ecosystems in global climate change.« less

MONTHLY REPORT OF DEVELOPMENT, SEPTEMBER 1963

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

None

1964-10-31

Methods for separating germanium from Taiga carbonaceous shale by flotation and salt roasting are described. The recovery of vanadium from Beaverlodge mill tailings by carbonate leaching is briefly discussed. Methods of chemical analysis are also discussed. (N.W.R.)

Microbiota of the ground air layers in natural and industrial zones of the Kola Arctic.

PubMed

Korneykova, Maria V; Evdokimova, Galina A

2018-02-23

The fungi and bacteria number, as well as the species composition of the fungi in the ground air layer in the European Arctic region of Russia, primarily in the tundra (the Rybachy Peninsula), in the subzone of the northern taiga (the Pasvik State Nature Reserve) and in the industrial areas (the Copper-Nickel Plant "Pechenganickel," the Kandalaksha Aluminum Plant) have been studied. One hundred and ninety-two atmosphere air samples of various ecosystems have been analyzed. The sample collection took place in the summer-autumn period (June, July, September, in 2012-2015) with the aspirator, precipitating microorganisms on the surface of media. The number of microorganisms per 1 m 3 of air was calculated. The portion of the airborne fungi in the ground air layer both in the tundra and in the taiga was higher in comparison with the bacteria, and amounted to 60-77% of the total number colony forming units (CFU). The least number of microorganisms in the investigated period was registered in the Barents Sea coastal atmospheric air, only 11-15 microbial CFU per 1 m 3 . The airborne fungi diversity in the taiga zone was richer than in the tundra. The fungi of the g. Penicillium predominated in both zones air. Bacteria gram-positive (the division Fermicutes) predominated within the bacterial biota. The species Penicillium decumbens, P. raistrickii prevailed in the air of the background tundra zone regions. The representatives of the genus Torula and Sterilia mycelia, P. raistrickii predominated in the taiga zone. Close by the Copper-Nickel Plant (about 3 km), the air bacterial contamination (100-600 CFU per 1 m 3 ) was revealed, with prevailing bacteria gram-negative (the division Gracilicutes). The species Cladosporium oxysporum predominated in the air to the greatest possible extent of the contaminated region due to the emissions of the Kandalaksha Aluminum Plant. The species Gongronella butleri were uppermost due to the emissions of the Copper-Nickel Plant �

Siberian Fires

Atmospheric Science Data Center

2013-04-16

... not be retrieved are shown as dark gray. Fire is an important ecological factor in the taiga forests, but in this region a ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

78 FR 65843 - General Provisions; Revised List of Migratory Birds

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

..., 2008, 2009, and 2010), on matters of taxonomy, nomenclature, and the sequence of species and other... Flycatcher, Ficedula albicilla (AOU 1982, 1983, 1998, 2006); Dark-sided Flycatcher, Muscicapa sibirica (AOU...). Mugimaki Flycatcher, Ficedula mugimaki (1). Taiga Flycatcher, Ficedula albicilla (1). Dark-sided Flycatcher...

Ecosystems of the Great Land. Teacher's Guide.

ERIC Educational Resources Information Center

Strom-Aronson, Melissa; Pohl, Janis

This is the Teacher's Guide for six video programs: "Introduction to Ecosystems"; "Tundra"; "Coastal Forest"; "Oceans"; "Impact of Human Habitation"; and "Taiga". The programs are designed to fit into courses for students from grades five through high school in which ecology is taught.…

Connections '95. Proceedings of a Faculty Conference (Victoria, British Columbia, Canada, May 1995).

ERIC Educational Resources Information Center

Miller, Carole S., Ed.; Sakari, Mary D., Ed.

"Connections '95" focused on educational collaboration and change and the process of becoming a professional. Following the introduction, "Creating the Context: Connections '95" (C. Miller and M. Sakari), the 16 conference papers are presented. The papers are: (1) "Taiga and Tundra: Art and Culture in a Changing…

Diagnostics of hydromorphism in soils of autonomous positions on the Severo-Sos'vinsk Upland (Western Siberia)

NASA Astrophysics Data System (ADS)

Avetov, N. A.; Sopova, E. O.; Golovleva, Yu. A.; Kiryushin, A. V.; Krasilnikov, P. V.

2014-11-01

The complex studies of hydromorphism features in taiga weakly differentiated soils using morphological (color), chemical (iron content in different extracts, indicators of reducing conditions (IRIS)), and geobotanic (using the Ramenskii scale) methods have led to ambiguous conclusions. In all the soils, surface gleying was manifested. According to the results obtained by different methods, the maximum reduction processes were related to either the sublitter or the next deeper horizon. The Schwertmann coefficient, the criterion of Bodegom, and the Ramenskii scale indicated an increase of hydromorphism in the soils studied in the following sequence: the lower part of the ridge slopes drained by the small gullies < the middle part of the slopes < the flat tops of the ridges < the depression between the ridges. The morphological diagnostics of gleying proved to be a less sensitive method, which can recognize only the most contrasting hydromorphic soils. The lower horizons in some taiga soils have a bluish gray color probably not related to the recent soil hydromorphism.

A Reconnaissance Snow Survey across Northwest Territories and Nunavut, Canada, April 2007

DTIC Science & Technology

2008-02-01

large outlier of taiga forest hundreds of kilometers north of the normal treeline . Figure 15. Sites used for analysis of longitudinal gradients...the Thelon River, the domain in Figure 17 is largely north of the treeline . As discussed in the previous section, no strong gradients in snow cover

Water quality and streamflow in the Caribou-Poker Creeks Research Watershed, central Alaska, 1978.

Treesearch

Jerry W. Hilgert; Charles W. Slaughter

1983-01-01

Baseline data from 1978 are presented on precipitation, streamflow, and chemical and biological water quality in a subarctic, taiga watershed. First-, second-, and third-order streams that drain undisturbed catchments embracing permafrost-underlain and permafrost-free landscapes were monitored; results are being used in analysis of the natural, undisturbed condition of...

Chapter 5: Wolverine

Treesearch

Vivian Banci

1994-01-01

The wolverine (Gulo gulo) is the largest-bodied terrestrial mustelid. Its distribution is circumpolar; it occupies the tundra, taiga, and forest zones of North America and Eurasia (Wilson 1982). North American wolverines are considered the same species as those in Eurasia. They are usually thought of as creatures of northern wilderness and remote...

Low-Concentration Kinetics of Atmospheric CH4 Oxidation in Soil and Mechanism of NH4+ Inhibition

PubMed Central

Gulledge, Jay; Schimel, Joshua P.

1998-01-01

NH4+ inhibition kinetics for CH4 oxidation were examined at near-atmospheric CH4 concentrations in three upland forest soils. Whether NH4+-independent salt effects could be neutralized by adding nonammoniacal salts to control samples in lieu of deionized water was also investigated. Because the levels of exchangeable endogenous NH4+ were very low in the three soils, desorption of endogenous NH4+ was not a significant factor in this study. The Km(app) values for water-treated controls were 9.8, 22, and 57 nM for temperate pine, temperate hardwood, and birch taiga soils, respectively. At CH4 concentrations of ≤15 μl liter−1, oxidation followed first-order kinetics in the fine-textured taiga soil, whereas the coarse-textured temperate soils exhibited Michaelis-Menten kinetics. Compared to water controls, the Km(app) values in the temperate soils increased in the presence of NH4+ salts, whereas the Vmax(app) values decreased substantially, indicating that there was a mixture of competitive and noncompetitive inhibition mechanisms for whole NH4+ salts. Compared to the corresponding K+ salt controls, the Km(app) values for NH4+ salts increased substantially, whereas the Vmax(app) values remained virtually unchanged, indicating that NH4+ acted by competitive inhibition. Nonammoniacal salts caused inhibition to increase with increasing CH4 concentrations in all three soils. In the birch taiga soil, this trend occurred with both NH4+ and K+ salts, and the slope of the increase was not affected by the addition of NH4+. Hence, the increase in inhibition resulted from an NH4+-independent mechanism. These results show that NH4+ inhibition of atmospheric CH4 oxidation resulted from enzymatic substrate competition and that additional inhibition that was not competitive resulted from a general salt effect that was independent of NH4+. PMID:9797279

Low-concentration kinetics of atmospheric CH{sub 4} oxidation in soil and mechanism of NH{sub 4}{sup +} inhibition

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

Gulledge, J.; Schimel, J.P.

1998-11-01

NH{sub 4}{sup +} inhibition kinetics for CH{sub 4} oxidation were examined at near-atmospheric CH{sub 4} concentrations in three upland forest soils. Whether NH{sub 4}{sup +}-independent salt effects could be neutralized by adding nonammoniacal salts to control samples in lieu of deionized water was also investigated. Because the levels of exchangeable endogenous NH{sub 4}{sup +} were very low in the three soils, desorption of endogenous NH{sub 4}{sup +} was not a significant factor in this study. The K{sub m(app)} values for water-treated controls were 9.8, 22, and 57 nM for temperate pine, temperate hardwood, and birch taiga soils, respectively. At CH{submore » 4} concentrations of {le}15 {micro}l liter{sup {minus}1}, oxidation followed first-order kinetics in the fine-textured taiga soil, whereas the coarse-textured temperate soils exhibited Michaelis-Menten kinetics. Compared to water controls, the K{sub m(app)} values in the temperate soils increased in the presence of NH{sub 4}{sup +} salts, whereas the V{sub max(app)} values decreased substantially, indicating that there was a mixture of competitive and noncompetitive inhibition mechanisms for whole NH{sub 4}{sup +} salts. Compared to the corresponding K{sup +} salt controls, the K{sub m(app)} values for NH{sub 4}{sup +} salts increased substantially, whereas the V{sub max(app)} values remained virtually unchanged, indicating that NH{sub 4}{sup +} acted by competitive inhibition. Nonammoniacal salts caused inhibition to increase with increasing CH{sub 4} concentrations in all three soils. In the birch taiga soil, this trend occurred with both NH{sub 4}{sup +} and K{sup +} salts, and the slope of the increase was not affected by the addition of NH{sub 4}{sup +}. Hence, the increase in inhibition resulted from an NH{sub 4}{sup +}-independent mechanism.« less

Simulation of the effect of air pollution on forest ecosystems in a region

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

Tarko, A.M.; Bykadorov, A.V.; Kryuchkov, V.V.

1995-03-01

This article describes a model of air pollution effects on spruce in forests of the northern taiga regions which have been exposed to air pollution from a large metallurgical industrial complex. Both the predictions the model makes about forest ecosystem degradation zones and the limitations of the model are discussed. 5 refs., 1 fig.

Disturbance ecology of North American boreal forests and associated northern mixed/subalpine forests [Chapter 3

Treesearch

James K. Agee

2000-01-01

Disturbance dynamics differ in the three subregions of the North American boreal forest (taiga, western United States, and eastern United States) where lynx are found, resulting in a range of potential effects on lynx populations. Fire severity tends to be high in most of the forest types where lynx habitat occurs, although subsequent succession will differ...

"Everything the World Turns on": Inclusion and Exclusion in Linda Hogan's "Power"

ERIC Educational Resources Information Center

Peters, Jesse

2013-01-01

In her novel "Power," Linda Hogan provides readers with a close look at how separatism and syncretism, or exclusion and inclusion, are complex ideologies that lead to complex decisions. A close look at the novel reveals that the tensions and sharp dichotomies between the traditional world of the Taiga elders and the European American world,…

Climate effects on vegetation vitality at the treeline of boreal forests of Mongolia

NASA Astrophysics Data System (ADS)

Klinge, Michael; Dulamsuren, Choimaa; Erasmi, Stefan; Nikolaus Karger, Dirk; Hauck, Markus

2018-03-01

In northern Mongolia, at the southern boundary of the Siberian boreal forest belt, the distribution of steppe and forest is generally linked to climate and topography, making this region highly sensitive to climate change and human impact. Detailed investigations on the limiting parameters of forest and steppe in different biomes provide necessary information for paleoenvironmental reconstruction and prognosis of potential landscape change. In this study, remote sensing data and gridded climate data were analyzed in order to identify main distribution patterns of forest and steppe in Mongolia and to detect environmental factors driving forest development. Forest distribution and vegetation vitality derived from the normalized differentiated vegetation index (NDVI) were investigated for the three types of boreal forest present in Mongolia (taiga, subtaiga and forest-steppe), which cover a total area of 73 818 km2. In addition to the forest type areas, the analysis focused on subunits of forest and nonforested areas at the upper and lower treeline, which represent ecological borders between vegetation types. Climate and NDVI data were analyzed for a reference period of 15 years from 1999 to 2013. The presented approach for treeline delineation by identifying representative sites mostly bridges local forest disturbances like fire or tree cutting. Moreover, this procedure provides a valuable tool to distinguish the potential forested area. The upper treeline generally rises from 1800 m above sea level (a.s.l.) in the northeast to 2700 m a.s.l. in the south. The lower treeline locally emerges at 1000 m a.s.l. in the northern taiga and rises southward to 2500 m a.s.l. The latitudinal gradient of both treelines turns into a longitudinal one on the eastern flank of mountain ranges due to higher aridity caused by rain-shadow effects. Less productive trees in terms of NDVI were identified at both the upper and lower treeline in relation to the respective total boreal forest

[Radioecological situation in the impact zone of the accidental underground nuclear explosion "Kraton-3" in the Republic of Sakha (Yakutia)].

PubMed

Sobakin, P I; Gerasimov, Ya R; Chevychelov, A P; Perk, A A; Goryachenkova, T A; Novikov, A P

2014-01-01

The paper reports on the results of a ground walking gamma- and gamma-spectrometric survey made in the impact zone of the accidental underground nuclear explosion "Kraton-3". Patterns of migration, 137Cs, 90Sr and Pu distribution in the soil-vegetable cover of the northern taiga on permafrost are considered. Radioeco- logical situation within the territory surveyed is noted as unfavorable.

Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog

NASA Astrophysics Data System (ADS)

Alekseychik, Pavel; Mammarella, Ivan; Karpov, Dmitry; Dengel, Sigrid; Terentieva, Irina; Sabrekov, Alexander; Glagolev, Mikhail; Lapshina, Elena

2017-08-01

Very few studies of ecosystem-atmosphere exchange involving eddy covariance data have been conducted in Siberia, with none in the western Siberian middle taiga. This work provides the first estimates of carbon dioxide (CO2) and energy budgets in a typical bog of the western Siberian middle taiga based on May-August measurements in 2015. The footprint of measured fluxes consisted of a homogeneous mixture of tree-covered ridges and hollows with the vegetation represented by typical sedges and shrubs. Generally, the surface exchange rates resembled those of pine-covered bogs elsewhere. The surface energy balance closure approached 100 %. Net CO2 uptake was comparatively high, summing up to 202 gC m-2 for the four measurement months, while the Bowen ratio was seasonally stable at 28 %. The ecosystem turned into a net CO2 source during several front passage events in June and July. The periods of heavy rain helped keep the water table at a sustainably high level, preventing a usual drawdown in summer. However, because of the cloudy and rainy weather, the observed fluxes might rather represent the special weather conditions of 2015 than their typical magnitudes.

The influence of fires on the properties of forest soils in the Amur River basin (the Norskii Reserve)

NASA Astrophysics Data System (ADS)

Tsibart, A. S.; Gennadiev, A. N.

2008-07-01

The influence of forest fires on the properties of taiga brown, gley taiga brown, and alluvial bog soils widespread in the area of the Norskii Reserve (the Amur River basin) was studied. During several years after the fire, the humus content increased, especially in the soils subjected to fires of high intensity. In the soils of steep slopes, the humus content decreased due to damage to the forest vegetation and activation of lateral runoff after the fire. As a rule, in the soils subjected to fire, the C ha-to-C fa ratio increased and correlated with the fire intensity. Some relationships between the forest fires and the acid-base properties of the soils were revealed. After the fires, the pH values often became higher. The stronger the fire, the higher the pH values. The stony soils differed from the other ones, since the reaction of their upper horizons turned out to be more acid after the fires. The analysis of the authors’ and literature data showed that the pyrogenic changes of some soil properties have been poorly studied and need further investigation, including their geographical aspects.

Oxygen isotope and deuterium composition of snow cover on the profile of Western Siberia from Tomsk to the Gulf of Ob

NASA Astrophysics Data System (ADS)

Vasil'chuk, Yu. K.; Shevchenko, V. P.; Lisitzin, A. P.; Budantseva, N. A.; Vorobiov, S. N.; Kirpotin, S. N.; Krizkov, I. V.; Manasypov, R. M.; Pokrovsky, O. S.; Chizhova, Ju. N.

2016-12-01

The purpose of this work is to study the variability of the isotope composition (δ18O, δD, d exc) of the snow cover on a long transect of Western Siberia from the southern taiga to the tundra. The study of the snow cover is of paleogeographic, paleogeocryological, and paleohydrological value. The snow cover of western Siberia was sampled on a broadly NS transzonal profile from the environs of Tomsk (southern taiga zone) to the eastern coast of the Gulf of Ob (tundra zone) from February 19 to March 4, 2014. Snow samples were collected at 31 sites. Most of the samples represented by fresh snow, i.e., snow that had fallen a day before the moment of sampling were collected in two areas. In the area of Yamburg, the snow specimens collected from the surface are most probably settled snow of different ages. The values of δ18O in the snow from Tomsk to Yamburg varied from-21.89 to-32.82‰, and the values of δD, from-163.3 to-261.2‰. The value of deuterium excess was in the range of 4.06-19.53‰.

Epiphytic lichenosynusia under conditions of chemical pollution: Dose-effect dependencies

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

Mikhailova, I.N.; Vorobeichik, E.L.

1995-11-01

The dose-effect dependencies, which characterize response of the epiphytic lichenosynusia of southern taiga in the Middle Urals to pollution by discharges of a copper-smelting plant, are substantially non-linear and, in most cases, have an S-shaped form. A transition from background to impact state is very sharp and begins when the background level of pollution is exceeded by 1.5 - 2.3 times.

Projected Impacts of 21st Century Climate Change on Potential Habitat for Vegetation and Forest Types in Russia

NASA Astrophysics Data System (ADS)

Soja, A. J.; Tchebakova, N. M.; Parfenova, E. I.; Cantin, A.; Conard, S. G.

2015-12-01

Global GCMs have demonstrated profound potential for projections to affect the distribution of terrestrial ecosystems and individual species at all hierarchical levels. We modeled progression of potential Russian ecotones and forest-forming species as the climate changes. Large-scale bioclimatic models were developed to predict Russian zonal vegetation (RuBCliM) and forest types (ForCliM) from three bioclimatic indices (1) growing degree-days above 5 degrees C; (2) negative degree-days below 0 C ; and (3) an annual moisture index (ratio of growing degree days to annual precipitation). The presence or absence of continuous permafrost was explicitly included in the models as limiting the forests and tree species distribution. All simulations to predict vegetation change across Russia were run by coupling our bioclimatic models with bioclimatic indices and the permafrost distribution for the baseline period and for the future 2020, 2050 and 2100 simulated by 3 GCMs (CGCM3.1, HadCM3 and IPSLCM4) and 3 climate change scenarios (A1B, A2 and B1). Under these climate scenarios, it is projected the zonobiomes will shift far northward to reach equilibrium with the change in climate. Under the warmer and drier projected future climate, about half of Russia would be suitable for the forest-steppe ecotone and grasslands, rather than for forests. Water stress tolerant light-needled taiga would have an increased advantage over water-loving dark-needled taiga. Permafrost-tolerant L. dahurica taiga would remain the dominant forest across permafrost. Increases in severe fire weather would lead to increases in large, high-severity fires, especially at boundaries between forest ecotones, which can be expected to facilitate a more rapid progression of vegetation towards a new equilibrium with the climate. Adaptation to climate change may be facilitated by: assisting migration of forests by seed transfers to establish genotypes that may be more ecologically suited as climate changes

Climate impacts on northern Canada: regional background.

PubMed

Prowse, Terry D; Furgal, Chris; Bonsal, Barrie R; Peters, Daniel L

2009-07-01

Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 degrees C in the south to as low as -20 degrees C in the high Arctic islands. A similar contrast characterizes precipitation, which can be > 700 mm y(-1) in some southern alpine regions to as low as 50 mm y(-1) over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

Silicon Taiga: SEZ in Russia, Problems and Perspectives

NASA Astrophysics Data System (ADS)

Rakhmenkulova, I.; Zhitov, E.

2005-12-01

Russian economy is known to be oil and gas dependent nowadays. Good educational system and high-quality diplomas of some schools together with bad living conditions and poor social security cause brain-drain and therefore make the country economy less competitive and even more resource dependent. To change the situation and to use intellectual resources properly Russian Government approved the law concerning setting up of Special Economic Zones (SEZ) in about 10 regions. SEZ can be defined as a territory of Russian Federation, an attractive for business offshore zone, having tax privileges and open to investments. Both residents and non-residents can do business there. The choice of the zone location is based on free competition. Such regions as Novosibirsk, Moscow, Sanct Petersburg, Tomsk and some Far East regions approved their intention to participate in the Project. 10 SEZ are expected to appear in 2006. Russian Government decided to create an IT center in Novosibirsk Scientific Center (Academgorodok), a place where more than 30 scientific institutions and Novosibirsk State University are located. Academgorodok is known by its intellectual potential not only in Russia but all over the world. The IT center Project includes the construction of a business center and several university buildings. This zone will be very attractive for investments and business. The concept of `continuous education' is used in Academgorodok. This means that young `geostars' are `nourished' from the middle school age, then continue their education at Novosibirsk State University (NSU). The NSU graduates work not only in Russian companies, but in such companies as Schlumberger, Shell, Halliburton, and others. Thus Novosibirsk Scientific Center (Academgorodok) can be very attractive for domestic and foreign investments because of its intellectual resources and educational policy, as well as a future SEZ. Several international geo-companies have already opened their offices there.

Soil temperature of peatland landscapes as a factor in the development of exogenous processes of biogenic relief formation in engineering development of territory

NASA Astrophysics Data System (ADS)

Korkin, S.; Talyneva, O.; Kail, E.

2018-03-01

In the presented work we consider mire landscapes in the context of temperature monitoring. The mire landscapes in engineering development of the territory are very sensitive to anthropogenic impact that leads to a change in surface conditions, changes in natural succession and, as a rule, to changes in soil temperature and properties, which in turn may develop a complex of hostile geodynamic processes. For this study we used recording systems for field measurement of peat and subsoil temperatures. The measurements were made in two key areas: the territory of the north-taiga landscapes of Western Siberia (the Siberian Ridges), and the territory of the middle-taiga landscapes of Western Siberia (the Ob middle-river lowland). The paper analyses the data obtained from five observation sites (3, 5, 5a, 6 and 8) referred to hydromorphic landscapes. For the territory of the Siberian Ridges the 5-year average soil temperature was 3°C. For the Ob middle-river lowland the 6-year average soil temperature was 4.2°C. The annual soil temperature in the period 2015-2016 for Site 5a (man-disturbed area) was 8.3°C at all depths, which is 3.8°C higher than in a natural bog (Site 5 was a control area).

Central Asia, Physical Geography Handbook.

DTIC Science & Technology

1960-06-20

saxaul 2 north of the southern boundary of the habitat of larch and the presence of a dwarf-halophyte desert one degree of lati- tude from a pine taiga...deserts where the latter border stony deserts. On "kharmyk" habitats there is formed a special type of sandy?desert landscape which has’been named the...Characteristic for animals of the desert, particularly ungulates, are seasonal and irregular migrations within their general habitat . Desert

[Energy and mass exchange and the productivity of the main ecosystems of Siberia (from eddy covariance measurements). 1. Heat balance structure in the vegetation season].

PubMed

Chebakova, N M; Vygodskaia, N N; Arnet, A; Belelli Markezini, L; Kolle, O; Kurbatova, Iu A; Parfenova, E I; Valentini, R; Vaganov, E A; Shul'tse, E D

2013-01-01

Direct measurements of heat balance (turbulent heat transfer and evaporation heat consumption) by the method of turbulent pulsations in 1998-2000 and 2002-2004 were used to obtain information on the daily, seasonal, and annual dynamics of energy fluxes and mass transfer between the atmosphere and the typical ecosystems of Siberia (middle-taiga pine forest and raised bog, true four-grass steppe, with the use of data for typical tundra) along the Yenisei meridian (90 degrees E).

Carbon dioxide in Arctic and subarctic regions

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

Gosink, T. A.; Kelley, J. J.

1981-03-01

A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, themore » hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.« less

Preliminary estimating the contemporary sedimentation trend in dry valley bottoms of first-order catchments of different landscape zones of the Russian Plain using the 137Cs as a chronomarker

NASA Astrophysics Data System (ADS)

Sharifullin, A.; Gusarov, A.; Gafurov, A.; Essuman-Quainoo, B.

2018-01-01

A general trend of erosion processes over the last 50-60 years can be estimated by dating sediments washed off from arable lands and accumulated in the first-order dry valleys bottoms. Three small (first-order) catchments were chosen as objects of the study. They are located, respectively, in the southern part of the taiga zone, the zone of temperate broad-leaf forests and the forest-steppe zone of the Russian Plain. To date the sediments accumulated in the bottoms the radioactive caesium-137 (137Cs) of global (since 1954) and Chernobyl origin (1986) had been used as a chronomarker. The average (for all the catchments) sedimentation rates during the global 137Cs fallout period (1963(1954)-1986) are at least 0.88-2.71 cm per year.For the period that has passed since the Chernobyl accident (1986-2015(2016)) the average rates were 0.15-1.07 cm per year. The greatest reduction in the sedimentation rates is observed in the subzone of the southern taiga, the lowest one is in the forest-steppe zone of the Russian Plain. The main reason for such significant reduction in the rates of sedimentation of the soil erosion products in the dry valley bottoms was a reduction of surface runoff within the catchments during a snowmelt period, as well as crop-rotation changes there.

Fate of leaf-litter N in forest and grassland along a pedo-climatic gradient in south-western Siberia: an in situ 15N-labelling experiment

NASA Astrophysics Data System (ADS)

Brédoire, Félix; Zeller, Bernd; Nikitich, Polina; Barsukov, Pavel A.; Rusalimova, Olga; Bakker, Mark R.; Legout, Arnaud; Bashuk, Alexander; Kayler, Zachary E.; Derrien, Delphine

2017-04-01

The suitability of Siberia for agriculture is expected to increase in the next decades due to strong and rapid climatic changes, but little is known on the environmental drivers of soil fertility there, especially nitrogen (N). Plant-available N is mainly derived from litter decomposition. South-western (SW) Siberia is located on the transition between several bioclimatic zones that are predicted to shift and extend along with climate change (steppe, forest-steppe, sub-taiga). The soils of this region are formed on a common loess deposit but they are submitted to different climatic conditions and vegetation cover. In the south of the region, typically in steppe/forest-steppe, soil freezes over winter because of a relatively shallow snow-pack, and water shortages are frequent in summer. In the north, typically in sub-taiga, the soil is barely frozen in winter due to a thick snow-pack and sufficient soil moisture in summer. In this study, we characterized the dynamics of leaf litter decomposition and the transfer of N from leaf litter to the soil and back to plants. Four sites were chosen along a climate gradient (temperature, precipitation and snow depth). At each site, we applied 15N-labelled leaf litter on the soil surface in experimental plots in an aspen (Populus tremula L.) forest and in a grassland. Twice a year during three years, we tracked the 15N derived from the decomposing labelled-litter in the organic layers, in the first 15 cm of the soil, and in above-ground vegetation. Soil temperature and moisture were monitored at a daily timestep over three years and soil water budgets were simulated (BILJOU model, Granier et al. 1999). We observed contrasting patterns in the fate of litter-derived 15N between bioclimatic zones. Over three years, along with faster decay rates, the release of leaf litter-N was faster in sub-taiga than in forest-steppe. As such, higher quantities of 15N were transferred into the soil in sub-taiga. The transfer was also deeper there

Mid-late Holocene climate and vegetation in northeastern part of the Altai Mountains recorded in Lake Teletskoye

NASA Astrophysics Data System (ADS)

Rudaya, Natalia; Nazarova, Larisa; Novenko, Elena; Babich, Valery; Kalugin, Ivan; Daryin, Andrei

2015-04-01

We report the first high-resolution (with intervals ca. 20-50 years) late-Holocene (4200 yr BP) pollen record from Lake Teletskoye, Altai Mountains, obtained from the underwater Ridge of Sofia Lepneva in 2006 (core Tel 2006). The study presents (i) the results of palynological analysis of Tel 2006; (ii) the results of spectral analysis of natural cycles based on the periodical fluctuation of taiga-biome curve; and (iii) quantitative reconstructions of the late-Holocene regional vegetation, woody coverage and climate in northern part of the Altai Mountains in order to define place of Northeast Altai on the map of the late-Holocene Central Asian environmental history. Late Holocene vegetation of the northeastern part of Altai recorded in Tel 2006 core is characterized by spread of dark-coniferous forest with structure similar to modern. Dominant trees, Siberian pine (Pinus sibirica) and Siberian fir (Abies sibirica), are the most ecological sensitive taxa between Siberian conifers (Shumilova, 1962), that as a whole suggests mild and humid climatic conditions during last 4200 years. However, changes of pollen taxa percentages and results of numerical analysis reveal pronounced fluctuation of climate and vegetation. Relatively cool and dry stage occurred prior to ca. 3500 cal yr BP. Open vegetation was widespread in the region with maximum deforestation and minimal July temperatures between 3800-3500 cal yr BP. Steppe-like communities with Artemisia, Chenopodiaceae and Cyperaceae could grow on the open sites around Lake Teletskoye. Reconstructed woody coverage is very low and varies between 29-35%. After ca. 3500 cal yr BP the area of dark-coniferous mountain taiga has significantly enlarged with maximums of woody coverages and taiga biome scores between ca. 2470-1040 cal yr BP. In the period of ~3500-2500 cal yr BP the averages July temperatures increased more than 1 0C. Climate became warmer and wetter. During last millennium (after 1040 cal yr BP) average July

Hieracium sinoaestivum (Asteraceae), a new species from North China

PubMed Central

Sennikov, Alexander N.

2014-01-01

Abstract Hieracium sinoaestivum Sennikov sp. nov. is described as new to science and illustrated. This presumably apomictic species is solely known from two old collections made in a single locality in the Shanxi Province of China. It belongs to the hybridogenous group Hieracium sect. Aestiva (Hieracium sect. Prenanthoidea × Hieracium sect. Umbellata) and is most similar to Hieracium veresczaginii from southern Siberia. The new species occurs at low altitudes in the forest belt of Lülian Mts. and belongs to taiga forest elements. PMID:25197222

Effects of soil freezing and thawing on vegetation carbon density in Siberia: A modeling analysis with the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM)

NASA Astrophysics Data System (ADS)

Beer, C.; Lucht, W.; Gerten, D.; Thonicke, K.; Schmullius, C.

2007-03-01

The current latitudinal gradient in biomass suggests a climate-driven limitation of biomass in high latitudes. Understanding of the underlying processes, and quantification of their relative importance, is required to assess the potential carbon uptake of the biosphere in response to anticipated warming and related changes in tree growth and forest extent in these regions. We analyze the hydrological effects of thawing and freezing of soil on vegetation carbon density (VCD) in permafrost-dominated regions of Siberia using a process-based biogeochemistry-biogeography model, the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). The analysis is based on spatially explicit simulations of coupled daily thaw depth, site hydrology, vegetation distribution, and carbon fluxes influencing VCD subject to climate, soil texture, and atmospheric CO2 concentration. LPJ represents the observed high spring peak of runoff of large Arctic rivers, and simulates a realistic fire return interval of 100 to 200 years in Siberia. The simulated VCD changeover from taiga to tundra is comparable to inventory-based information. Without the consideration of freeze-thaw processes VCD would be overestimated by a factor of 2 in southern taiga to a factor of 5 in northern forest tundra, mainly because available soil water would be overestimated with major effects on fire occurrence and net primary productivity. This suggests that forest growth in high latitudes is not only limited by temperature, radiation, and nutrient availability but also by the availability of liquid soil water.

New Nipponentomon species from northern Asia (Protura: Acerentomata, Nipponentomidae).

PubMed

Bu, Yun; Wu, Dong Hui; Shrubovych, Julia; Yin, Wen Ying

2013-01-01

Nipponentomnon imadatei sp. nov. from Northeast China and Nippon entomon taiga sp. nov. from Siberia, Russia are described. Nipponentornon heterothrixi Yin & Xie is redescribed based on type materials and lectotype and paralectotypes are designed for the species. Nipponentonon bidentatumn and N. nippon are reported for the first time from China. Nipponentornon imnadatei sp. nov. is characterized by a short labrum, absence of seta Pla on tergite VII and presence of three A-setae on sternites IV-VI. It is similar to N. jaceki from the Russian Far East, but differs in the shape of the comb, shape of setaβ1 on the foretarsus, length of sensillum e on the foretarsus, and in chaetotaxy on tergite I and sternites IV-VI. Nipponentomnon taiga sp. nov. is characterized by a short labrum, presence of seta P2a' on nota, seta P0a on tergite I, seta Pla on tergites I-VII, and absence of seta P3a on tergites II-VII. It is similar to N. heterothrixi, but differs in absence of seta d6 on the head, shape of accessory setae on tergites VI and VII, long and setiform setaβ1, and shorter sensilla c, e, g, a' and c' on the foretarsus than in sensilla in N. heterothrixi and in the porotaxy. A key for the world species of the genus is provided and the porotaxy of five species is reported in detail.

Characterizing Early Succession Following Wildfires at Different Severities in Boreal Bog and Fen Peatlands

NASA Astrophysics Data System (ADS)

Ernst, E. J.; Bourgeau-Chavez, L. L.; Kane, E. S.; Wagenbrenner, J. W.; Endres, S.

2016-12-01

The Arctic-boreal region is experiencing changes in climate, trending toward warmer summers, resulting in a greater occurrence of wildfires with longer burning periods and higher intensities. Drought-like conditions have dried surface fuels, leading to a higher probability of ignition, even in lowland peatlands. Previous work has been done to characterize post-fire succession rates in Arctic-boreal upland sites, but much less is known of fire effects and early successional dynamics in lowlands. Wildland fires are the number one disturbance in Canada's Northwest Territories (NWT), which characteristically burn at high intensities with large flame fronts, and result in some of the biggest wildfires in the world. Areas surrounding the Great Slave Lake, NWT—including parts of the Taiga Plains, Taiga Shield, and Boreal Plains ecozones—experienced exceptional wildfire activity in 2014 and 2015. We characterized burn severity of the bog and fen peat surface and canopy layers at several burned sites. To determine if the severe ground or crown wildfires were stand-replacing events, we characterized post-fire vegetation in peatlands in 2015 and 2016 based on seedling regeneration. We stratified sites according to estimated water residence times across the three ecozones and made comparisons between data collected at the same sites across years. This work adds much needed context for post-fire succession in boreal peatland ecosystems, as the susceptibility of these systems to burning will continue to increase with a warming climate.

On the core bacterial flora of Ixodes persulcatus (Taiga tick).

PubMed

Sui, Shuo; Yang, Yu; Sun, Yi; Wang, Xumin; Wang, Guoliang; Shan, Guangle; Wang, Jiancheng; Yu, Jun

2017-01-01

Ixodes persulcatus is a predominant hard tick species that transmits a wide range of human and animal pathogens. Since bacterial flora of the tick dwelling in the wild always vary according to their hosts and the environment, it is highly desirable that species-associated microbiomes are fully determined by using next-generation sequencing and based on comparative metagenomics. Here, we examine such metagenomic changes of I. persulcatus starting with samples collected from the wild ticks and followed by the reared animals under pathogen-free laboratory conditions over multiple generations. Based on high-coverage genomic sequences from three experimental groups-wild, reared for a single generation or R1, and reared for eight generations or R8 -we identify the core bacterial flora of I. persulcatus, which contains 70 species that belong to 69 genera of 8 phyla; such a core is from the R8 group, which is reduced from 4625 species belonging to 1153 genera of 29 phyla in the wild group. Our study provides a novel example of tick core bacterial flora acquired based on wild-to-reared comparison, which paves a way for future research on tick metagenomics and tick-borne disease pandemics.

Taiga forest stands and SAR: Monitoring for subarctic global change

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

Way, J.; Kwok, R.; Viereck, L.

1992-03-01

In preparation for the first European Earth Remote Sensing (ERS-1) mission, a series of multitemporal, multifrequency, multipolarization aircraft synthetic aperture radar (SAR) data sets were acquired over the Bonanza Creek Experimental Forest near Fairbanks, Alaska in March 1988. Significant change in radar backscatter was observed over the two-week experimental period due to changing environmental conditions. These preliminary results are presented to illustrate the opportunity afforded by the ERS-1 SAR to monitor temporal change in forest ecosystems.

On the core bacterial flora of Ixodes persulcatus (Taiga tick)

PubMed Central

Sun, Yi; Wang, Xumin; Wang, Guoliang; Shan, Guangle; Wang, Jiancheng; Yu, Jun

2017-01-01

Ixodes persulcatus is a predominant hard tick species that transmits a wide range of human and animal pathogens. Since bacterial flora of the tick dwelling in the wild always vary according to their hosts and the environment, it is highly desirable that species-associated microbiomes are fully determined by using next-generation sequencing and based on comparative metagenomics. Here, we examine such metagenomic changes of I. persulcatus starting with samples collected from the wild ticks and followed by the reared animals under pathogen-free laboratory conditions over multiple generations. Based on high-coverage genomic sequences from three experimental groups–wild, reared for a single generation or R1, and reared for eight generations or R8 –we identify the core bacterial flora of I. persulcatus, which contains 70 species that belong to 69 genera of 8 phyla; such a core is from the R8 group, which is reduced from 4625 species belonging to 1153 genera of 29 phyla in the wild group. Our study provides a novel example of tick core bacterial flora acquired based on wild-to-reared comparison, which paves a way for future research on tick metagenomics and tick-borne disease pandemics. PMID:28692666

[Nitrogen pool in northern taiga larch forests of Central Siberia].

PubMed

Shugaleĭ, L S; Vedrova, E F

2004-01-01

The pools of nitrogen in different blocks of forest ecosystems and its cycle in the soil are considered. It is shown that the bulk of nitrogen concentrates in the soil and dead organic matter (necromass) of an ecosystem. The nitrogen pool of forest litters and soils consists by 83-93% of the inert compounds that cannot be involved in the biological cycle. Mineralization of organic nitrogen-containing substances in the litters and soils usually yields ammonium as an end product. The amount of nitrogen mineralized over the growing season is partially expended for annual plant increment (30-65%) and immobilization (12-17%), with its large proportion being found in the soil.

Climate-induced mortality of "dark needle conifer" in Siberian taiga

NASA Astrophysics Data System (ADS)

Kharuk, Viacheslav; Im, Sergei; Petrov, Ilya

2017-04-01

Within Siberia fir (Abies sibirica) and Siberian pine (Pinus sibirica) (so called "dark needle conifers", DNC) mortality increased in the southern part of the DNC range. Siberian pine and fir showed decreased radial growth increment within southern Siberia since the 1980s with increasing mortality recorded since the year 2000. Tree ring width was strongly correlated with vapor pressure deficit, aridity and root zone moisture. Water stress from droughts made trees more susceptible to insect attacks causing mortality in about 10% of DNC stands in southern Siberia. Biogeographically, tree mortality was located within the DNC - forest-steppes transition. Tree mortality was significantly correlated with drought and soil moisture anomalies. Within the interior of the DNC range mortality occurred within relief features with high water stress risk (i.e., steep convex south facing slopes with shallow well-drained soils). In general, DNC mortality in Siberia was induced by increased aridity and severe drought (inciting factors) in synergy with biotic attacks (contributing factor). In particular, bark beetle Polygraphus proximus made a strong input on the fir mortality. In future climate scenarios with predicted increase in aridity DNC could be eliminated from the southern part of its current range and will be replaced by drought-resistant conifers and broadleaf species (e.g., Larix sibirica, Pinus sylvestris, and Betula pubescence).

Parametric analysis of cherenkov light LDF from EAS for high energy gamma rays and nuclei: Ways of practical application

NASA Astrophysics Data System (ADS)

Elshoukrofy, A. Sh. M.; Postnikov, E. B.; Korosteleva, E. E.; Sveshnikova, L. G.; Motaweh, H. A.

2017-06-01

In this paper we propose a `knee-like' approximation of the lateral distribution of the Cherenkov light from extensive air showers in the energy range 30-3000 TeV and study a possibility of its practical application in high energy ground-based gamma-ray astronomy experiments (in particular, in TAIGA-HiSCORE). The approximation has a very good accuracy for individual showers and can be easily simplified for practical application in the HiSCORE wide angle timing array in the condition of a limited number of triggered stations.

Weather Extremes Around the World

DTIC Science & Technology

1974-04-01

the lowest temperature has been recorded at Ust’Shchiigor in the Soviet Union at about 55°N, 50°E.4S This station, located near the Siberian border... Siberian taiga (northern coniferous forest). It is an area of extreme eontinentality, lying near the eastern end of the world’s largest landmass and...HO hours per year Mouse I’ciik Lighthouse, Mistake Island. Maine l"\\ig is a cloud al the surface of Ihe earth, eonsislinj» of a nti’ltilude of

[Migration in soil and accumulation in plants of peaceful nuclear explosion products in Perm region].

PubMed

Raskosha, N G; Shuktova, I I

2015-01-01

The data on the migration capacity in soil and accumulation of 238Pu, 239, 240Pu, 137Cs and 90Sr by plants in the area of a peaceful nuclear explosion located in the taiga zone are presented. The influence of the soil parameters on the distribution and transformation forms of the radionuclides in the podzolic soil profile was studied. The major amounts of man-made radionuclides were found in the matter of the ground lip. The accumulation parameters of pollutants by plants were the highest for the leaves, young branches and conifer of trees.

Effects of nontropical forest cover on climate

NASA Technical Reports Server (NTRS)

Otterman, J.; Chou, M.-D.; Arking, A.

1984-01-01

The albedo of a forest with snow on the ground is much less than that of snow-covered low vegetation such as tundra. As a result, simulation of the Northern Hemisphere climate, when fully forested south of a suitably chosen taiga/tundra boundary (ecocline), produces a hemispheric surface air temperature 1.9 K higher than that of an earth devoid of trees. Using variations of the solar constant to force climate changes in the GLAS Multi-Layer Energy Balance Model, the role of snow-albedo feedback in increasing the climate sensitivity to external perturbations is reexamined. The effect of snow-albedo feedback is found to be significantly reduced when a low albedo is used for snow over taiga, south of the fixed latitude of the ecocline. If the ecocline shifts to maintain equilibrium with the new climate - which is presumed to occur in a prolonged perturbation when time is sufficient for trees to grow or die and fall - the feedback is stronger than for a fixed ecocline, especially at high latitudes. However, this snow/vegetation-albedo feedback is still essentially weaker than the snow-albedo feedback in the forest-free case. The loss of forest to agriculture and other land-use would put the present climate further away from that associated with the fully forested earth south of the ecocline and closer to the forest-free case. Thus, the decrease in nontropical forest cover since prehistoric times has probably affected the climate by reducing the temperatures and by increasing the sensitivity to perturbations, with both effects more pronounced at high latitudes.

Large forest fires in Canada, 1959-1997

NASA Astrophysics Data System (ADS)

Stocks, B. J.; Mason, J. A.; Todd, J. B.; Bosch, E. M.; Wotton, B. M.; Amiro, B. D.; Flannigan, M. D.; Hirsch, K. G.; Logan, K. A.; Martell, D. L.; Skinner, W. R.

2003-01-01

A Large Fire Database (LFDB), which includes information on fire location, start date, final size, cause, and suppression action, has been developed for all fires larger than 200 ha in area for Canada for the 1959-1997 period. The LFDB represents only 3.1% of the total number of Canadian fires during this period, the remaining 96.9% of fires being suppressed while <200 ha in size, yet accounts for ~97% of the total area burned, allowing a spatial and temporal analysis of recent Canadian landscape-scale fire impacts. On average ~2 million ha burned annually in these large fires, although more than 7 million ha burned in some years. Ecozones in the boreal and taiga regions experienced the greatest areas burned, with an average of 0.7% of the forested land burning annually. Lightning fires predominate in northern Canada, accounting for 80% of the total LFDB area burned. Large fires, although small in number, contribute substantially to area burned, most particularly in the boreal and taiga regions. The Canadian fire season runs from late April through August, with most of the area burned occurring in June and July due primarily to lightning fire activity in northern Canada. Close to 50% of the area burned in Canada is the result of fires that are not actioned due to their remote location, low values-at-risk, and efforts to accommodate the natural role of fire in these ecosystems. The LFDB is updated annually and is being expanded back in time to permit a more thorough analysis of long-term trends in Canadian fire activity.

Space Radar Image of Baikal Lake, Russia

NASA Technical Reports Server (NTRS)

1994-01-01

This is an X-band black-and-white image of the forests east of the Baikal Forest in the Jablonowy Mountains of Russia. The image is centered at 52.5 degrees north latitude and 116 degrees east longitude near the mining town of Bukatschatscha. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on October 4, 1994, during the second flight of the spaceborne radar. This area is part of an international research project known as the Taiga Aerospace Investigation using Geographic Information System Applications.

Mapping wetland and forest landscapes in Siberia with Landsat data

NASA Astrophysics Data System (ADS)

Maksyutov, Shamil; Kleptsova, Irina; Glagolev, Mikhail; Sedykh, Vladimir; Kuzmenko, Ekaterina; Silaev, Anton; Frolov, Alexander; Nikolaeva, Svetlana; Fedorov, Alexander

2014-05-01

Landsat data availability provides opportunity for improving the knowledge of the Siberian ecosystems necessary for quantifying the response of the regional carbon cycle to the climate change. We developed a new wetland map based on Landsat data for whole West Siberia aiming at scaling up the methane emission observations. Mid-summer Landsat scenes were used in supervised classification method, based on ground truth data obtained during multiple field surveys. The method allows distinguishing following wetland types: pine-dwarf shrubs-sphagnum bogs or ryams, ridge-hollows complexes, shallow-water complexes, sedge-sphagnum poor fens, herbaceous-sphagnum poor fens, sedge-(moss) poor fens and fens, wooded swamps or sogra, palsa complexes. In our estimates wetlands cover 36% of the taiga area. Total methane emission from WS taiga mires is estimated as 3.6 TgC/yr,which is 77% larger as compared to the earlier estimate based on partial Landsat mapping combined with low resolution map due to higher fraction of fen area. We make an attempt to develop a forest typology system useful for a dynamic vegetation modeling and apply it to the analysis of the forest type distribution for several test areas in West and East Siberia, aiming at capability of mapping whole Siberian forests based on Landsat data. Test region locations are: two in West Siberian middle taiga (Laryegan and Nyagan), and one in East Siberia near Yakutsk. The ground truth data are based on analysis of the field survey, forest inventory data from the point of view of the successional forest type classification. Supervised classification was applied to the areas where ample ground truth and inventory data are available, using several limited area maps and vegetation survey. In Laryegan basin the upland forest areas are dominated (as climax forest species) by Scots pine on sandy soils and Siberian pine with presence of fir and spruce on the others. Those types are separable using Landsat spectral data alone. In

Windthrow and fallow-forest successions impacts in soil carbon stocks and GHG fluxes spatial variability and dynamics in the Central Russia' reserve spruce ecosystems

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Ivanov, Alexey; Komarova, Tatyana; Valentini, Riccardo

2015-04-01

High spatial and temporal variability is mutual feature for most forest soils that is especially obvious in case of their carbon stocks and GHG fluxes. This phenomenon is generally well-known but not so often becomes the object of special precision investigation in detail and small scales so there are still serious gaps in its principal factors understanding due to their high bioclimatic, regional, landscape, tree species and temporal variability. Southern taiga is one of the most environmentally important world zonal forest ecosystems due to its still comparatively intensive carbon biogeochemical cycle and huge area in the northern Eurasia with strong anthropogenic impacts by Western & Central European and Southern & Eastern Asian regions. Central Forest Biospheric Reserve (Tver region, 360 km to North-West from Moscow) is the principal southern-taiga reserve in the European territory of Russia. Since start of its research activity in 1939 the reserve became the regional center of mature spruce ecosystem structure and dynamics investigation. In 1970-1980-s there have been done complex investigations of windthrow soil patterns and fallow-forest successions. Since middle of 1990-s the ecosystem-level GHG fluxes have been observed by eddy covariance method. Since 2012 the detailed year-round monitoring is running in the southern-taiga zonal station of the regional system RusFluxNet with especial attention on the soil carbon stocks and GHG fluxes spatial variability and dynamics due to windthrow and fallow-forest successions (in frame of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266). Soil carbon dynamics is investigated in decades-hundred-year chronosequences of dominated parcels and different-size windthrow soil cover patterns, including direct investigation during last 33 years with detailed mapping, soil profile morphometrics and bulk density, morphogenetic and statistical analysis of mass data. Morphogenetic analysis of microrelief, soil profile

Soil respiration dynamics in the middle taiga of Central Siberia region

NASA Astrophysics Data System (ADS)

Makhnykina, Anastasia; Prokushkin, Anatoly; Polosukhina, Daria

2017-04-01

A large amount of carbon in soil is released to the atmosphere through soil respiration, which is the main pathway of transferring carbon from terrestrial ecosystems (Comstedt et al., 2011). Considering that boreal forests is a large terrestrial sink (Tans et al., 1990) and represent approximately 11 % of the Earth's total land area (Gower et al., 2001), even a small change in soil respiration could significantly intensify - or mitigate - current atmospheric increases of CO2, with potential feedbacks to climate change. The objectives of the present study are: (a) to study the dynamic of CO2 emission from the soil surface during summer season (from May to October); (b) to identify the reaction of soil respiration to different amount of precipitation as the main limiting factor in the region. The research was located in the pine forests in Central Siberia (60°N, 90°E), Russia. Sample plots were represented by the lichen pine forest, moss pine forest, mixed forest and anthropogenic destroyed area. We used the automated soil CO2 flux system based on the infrared gas analyzer -LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths -5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. The presence and type of ground cover substantially affects the value of soil respiration fluxes. The carbon dioxide emission from the soil surface averaged 5.4 ±2.3 μmol CO2 m-2 s-1. The destroyed area without plant cover demonstrated the lowest soil respiration (0.1-5.6 μmol CO2 m-2 s-1). The lowest soil respiration among forested areas was observed in the feathermoss pine forest. The lichen pine forest was characterized by the intermediate values of soil respiration. The maximum soil respiration values and seasonal fluctuations were obtained in the mixed forest (2.3-29.3 μmol CO2 m-2 s-1). The analysis of relation between soil CO2 efflux and climatic conditions identified the parameters with highest soil efflux rates. The influence of soil temperature on the soil CO2 efflux showed that an increase of soil efflux was observed from 0 °C to 16 °C. The temperature of more than 16 °C led to the inhibition of soil respiration process. The investigation of relationship between soil CO2 efflux and soil moisture revealed that the moisture from 0 to 0.3 m-3m-3 resulted in an increase of soil efflux. The moisture of more than 0.3 m-3m-3 led to the inhibition of soil respiration. Our study suggested that the decline of the rainfall and increase of temperature due to climate change could significantly decrease the CO2 emission from the Siberian boreal forests.

Monitoring of environmental conditions in taiga forests using ERS-1 SAR

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

Rignot, E.; Way, J.B.; McDonald, K.

1994-08-01

Synthetic-aperture radar images of forest site near Manley Hot Springs (64[degree]N, 151[degree]W), Alaska, were collected between August 1991 and December 1991, day and night, every 3 days, at C-band frequency ([lambda] = 5.7 cm), vertical receive and transmit polarization, by the European Space Agency First Remote Sensing Satellite, ERS-1. During the same period, air and soil temperatures and dielectric and gravimetric moisture properties of the forest canopy and forest floor were monitored in three forest stands dominated, respectively, by black spruce (Picea mariana), white spruce (Picea glauca), and balsam poplar (Populus balsamifera). The calibrated ERS-1 radar backscatter values, [sigma][degree], ofmore » the forest stands are shown to exhibit a pronounced temporal pattern, with little separability between tree species. The largest change in [sigma][degree], a 3-dB decrease almost independent of tree species, is observed in early winter when the soil and vegetation freeze. In the summer, temporal fluctuations in [sigma][degree] are about 1--2 dB in magnitude, depending on tree species. Diurnal variations in [sigma][degree] are as large as 2 dB during fall freeze-up, and less than 1 dB in summer and winter. These temporal variations in radar backscatter from the forest are interpreted using the MIMICS radar backscatter model and the in situ surface observations as due to changes in the dielectric properties of the forest floor and forest canopy induced by precipitation (summer), drought (fall), and freezing (fall-winter) events. In winter, [sigma][degree] increases across the entire landscape, probably because of volume scattering from large depth hoar ice crystals forming in the snow pack.« less

[Population dynamics of thrushes and seasonal resource partition].

PubMed

Burskiĭ, O V; Demidova, E Iu; Morkovin, A A

2014-01-01

We studied seasonal population dynamics in birds using four thrush species from the Yenisei middle taiga region as an example. Long-term data on bird route censuses, capture-mark-recapture, and nest observa- tions were incorporated in the analysis. Particularly, methodological problems that complicate a direct comparison between assessed numbers at different phases of the annual cycle are considered. The integrated analysis of the results allowed comparing changes in numbers, energy expenditure, age structure, migrating status, and density distribution of selected populations during the snowless period and relating them to seasonal changes in food resource abundance. Thrush population numbers within the breeding range, and their energy consumption in the Yenisei middle taiga proportionately reflect the seasonal change in abundance of food resources. The compliance between resource intake and carrying capacity of the environment is attained by: timing of arrival and departure regarding to the species' range of tolerance; change in numbers as a result of reproduction and mortality; change in numbers due to habitat changes and long-distance movements; increasing energetic expenditures during reproduction and molt; timing, intensity and replication of nesting attempts; timing of molt and proportion of molting individuals in a population; individual variations of the annual cycle. Reproductive growth of local bird populations is not fast enough to catch up with seasonal growth of ecosystems productivity. Superabundance of invertebrates at the peak of the season offers a temporal niche which, on the one hand, is suitable for species capable of diet switching, while, on the other hand, may be used by specialized consumers, namely tropical migrants for whom, at high resource level, a shortened breeding period suffices.

Quantitative assessment of pedodiversity and soil erosion within a karst sinkhole in the dry steppe subzone

NASA Astrophysics Data System (ADS)

Smirnova, M. A.; Gennadiev, A. N.

2017-08-01

A detailed study of the soil cover of a sinkhole (300 m2) in the dry steppe landscape of the Bogdinsk-Baskunchak Natural Reserve in Astrakhan oblast has been performed, and the factors of its differentiation have been analyzed. The indices of pedodiversity have been calculated and compared for karst sinkholes in the dry steppe and northern taiga landscapes. Quantitative parameters of the lateral migration of solid soil substances on the slopes of the sinkhole have been determined. The rate of soil erosion decreases from the slope of southern aspect to the slopes of western, northern, and eastern aspects. On the average, it is estimated at 0.4 mm/yr. The average rate of accumulation of solid substances on the lower parts of the slopes and in the bottom of the sinkhole reaches 0.74 mm/yr. A comparative analysis of the soil properties attests to their dependence on the particular position of a given soil within the sinkhole. Downward the slopes of the sinkhole, full-profile brown arid soils (Cambic Calcisols) are replaced by sierozem-like soils (Haplic Calcisols), light-humus poorly developed soils (Luvisols), lithozems (Leptosols), and stratified soils (stratozems, or Colluvic Regosols). The soils within the upper ring-shape soil microzone are more diverse and contrasting with respect to their morphological, physical, chemical, and physicochemical properties. The degree of soil contrasts decreases down the slopes of the sinkhole towards its bottom. The studied sinkhole is characterized by considerable pedodiversity. Quantitative parameters of pedodiversity for the sinkhole in the dry steppe zone are higher than those form the sinkholes in the northern taiga zone.

Large forest fires in Canada, 1959-1997

NASA Astrophysics Data System (ADS)

Stocks, B. J.; Mason, J. A.; Todd, J. B.; Bosch, E. M.; Wotton, B. M.; Amiro, B. D.; Flannigan, M. D.; Hirsch, K. G.; Logan, K. A.; Martell, D. L.; Skinner, W. R.

2002-01-01

A Large Fire Database (LFDB), which includes information on fire location, start date, final size, cause, and suppression action, has been developed for all fires larger than 200 ha in area for Canada for the 1959-1997 period. The LFDB represents only 3.1% of the total number of Canadian fires during this period, the remaining 96.9% of fires being suppressed while <200 ha in size, yet accounts for ˜97% of the total area burned, allowing a spatial and temporal analysis of recent Canadian landscape-scale fire impacts. On average ˜2 million ha burned annually in these large fires, although more than 7 million ha burned in some years. Ecozones in the boreal and taiga regions experienced the greatest areas burned, with an average of 0.7% of the forested land burning annually. Lightning fires predominate in northern Canada, accounting for 80% of the total LFDB area burned. Large fires, although small in number, contribute substantially to area burned, most particularly in the boreal and taiga regions. The Canadian fire season runs from late April through August, with most of the area burned occurring in June and July due primarily to lightning fire activity in northern Canada. Close to 50% of the area burned in Canada is the result of fires that are not actioned due to their remote location, low values-at-risk, and efforts to accommodate the natural role of fire in these ecosystems. The LFDB is updated annually and is being expanded back in time to permit a more thorough analysis of long-term trends in Canadian fire activity.

Extreme anthropogenic loads and the northern ecosystem condition

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

Kryuckkov, V.V.

1993-11-01

In the extreme North, the polar region of siberian Russia, the largest mining and processing enterprises for metallic and nonmetallic ores, coal, oil, and gas are situated. The extremely vulnerable boreal and polar ecosystems of the north are responding adversely to the impact of these activities, and are in danger of collapse because of them. The mechanisms of such impacts, their formation, continuous extension, and merger have been studied. The deforested and destroyed areas of former forest-tundra and taiga ecosystems resemble the Arctic zones of a much harsher environment more than the typical Arctic zones where they occur. 5 refs.,more » 3 figs., 2 tabs.« less

Tunguska, 1908: the gas pouch and soil fluidization hypothesis

NASA Astrophysics Data System (ADS)

Nistor, I.

2012-01-01

The Siberian taiga explosion of 30 June 1908 remains one of the great mysteries of the 20th century: millions of trees put down over an area of 2200 km2 without trace of a crater or meteorite fragments. Hundred years of failed searches have followed, resulting in as many flawed hypothesis which could not offer satisfactory explanations: meteorite, comet, UFO, etc. In the author's opinion, the cause is that the energy the explorers looked for was simply not there! The author's hypothesis is that a meteoroid encountered a gas pouch in the atmosphere, producing a devastating explosion, its effects being amplified by soil fluidization.

Lung and hearth nematodes in some Spanish mammals.

PubMed

Alvarez, F; Iglesias, R; Bos, J; Rey, J; Sanmartin Durán, M L

1991-01-01

Thirteen host species belonging to the orders Rodentia, Insectivora and Carnivora from various localities in Galicia (NW Spain) were examined for heart and lung parasites. The following species were found: Parastrongylus dujardini (5.5%) in Apodemus sylvaticus, Crenosoma striatum in Erinaceus europaeus (83%), Angiostrongylus vasorum, Crenosoma vulpis and Eucoleus aerophilus in Vulpes vulpes (3, 3.46 and 0.50%, respectively), Crenosoma taiga in Putorius putorius (100%) and Crenosoma sp. in Meles meles (25%). In Crocidura russula nematode larvae were found (3.3%). Mus musculus, Rattus norvegicus, Rattus rattus, Talpa caeca, Sorex araneus, Genetta genetta and Canis lupus were not parasitized by lung or heart parasites.

Space Radar Image of Baikal Lake, Russia

NASA Image and Video Library

1999-05-01

This is an X-band black-and-white image of the forests east of the Baikal Forest in the Jablonowy Mountains of Russia. The image is centered at 52.5 degrees north latitude and 116 degrees east longitude near the mining town of Bukatschatscha. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on October 4, 1994, during the second flight of the spaceborne radar. This area is part of an international research project known as the Taiga Aerospace Investigation using Geographic Information System Applications. http://photojournal.jpl.nasa.gov/catalog/PIA01754

Influence of north climatic conditions on the peat lipids composition

NASA Astrophysics Data System (ADS)

Serebrennikova, O. V.; Strelnikova, E. B.; Duchko, M. A.; Preis, Yu I.

2018-03-01

The paper studies the composition of lipid organic compounds of peat from the northern regions of the Russian Federation. Peat was sampled in the northern taiga, forest-tundra and tundra zones, characterized by various hydrothermal conditions and vegetation cover. n-Alkanes, fatty acids and their ethers, aldehydes, ketones, alcohols, tocopherols, squalene, bi-, tri- and pentacyclic terpenoids, as well as steroids were identified in peat lipids by gas chromatography-mass spectrometry. The dependences of the total content of lipids and the majority of the investigated compounds classes on the ambient temperature and vegetation, as well as the correlation between the composition of n-alkanes and humidity were revealed.

[Studies of the biological age in adult taiga ticks Ixodes persulcatus (Ixodinae)].

PubMed

Grigor'eva, L A

2013-01-01

The history of studies of the biological age in ixodid ticks is discussed. A method of estimation of the biological age in adult ticks of the genus Ixodes by the degree of fat inclusions in midgut cells and in the fat body is developed. An "age scale" for the determination of the calendar age was assumed.

Making do with less: Must sparse data preclude informed harvest strategies for European waterbirds?

USGS Publications Warehouse

Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper; Guillemain, Matthieu

2018-01-01

The demography of many European waterbirds is not well understood because most countries have conducted little monitoring and assessment, and coordination among countries on waterbird management has little precedent. Yet intergovernmental treaties now mandate the use of sustainable, adaptive harvest strategies, whose development is challenged by a paucity of demographic information. In this study, we explore how a combination of allometric relationships, fragmentary monitoring and research information, and expert judgment can be used to estimate the parameters of a theta-logistic population model, which in turn can be used in a Markov decision process to derive optimal harvesting strategies. We show how to account for considerable parametric uncertainty, as well as for different management objectives. We illustrate our methodology with a poorly understood population of taiga bean geese (Anser fabalis fabalis), which is a popular game bird in Fennoscandia. Our results for taiga bean geese suggest that they may have demographic rates similar to other, well-studied species of geese, and our model-based predictions of population size are consistent with the limited monitoring information available. Importantly, we found that by using a Markov decision process, a simple scalar population model may be sufficient to guide harvest management of this species, even if its demography is age-structured. Finally, we demonstrated how two different management objectives can lead to very different optimal harvesting strategies, and how conflicting objectives may be traded off with each other. This approach will have broad application for European waterbirds by providing preliminary estimates of key demographic parameters, by providing insights into the monitoring and research activities needed to corroborate those estimates, and by producing harvest management strategies that are optimal with respect to the managers’ objectives, options, and available demographic information.

Climate Effects on Methylmercury Bioaccumulation Along a Latitudinal Gradient in the Eastern Canadian Arctic

NASA Astrophysics Data System (ADS)

Chetelat, J.; Richardson, M.; MacMillan, G. A.; Amyot, M.; Hintelmann, H.; Crump, D.

2014-12-01

Recent evidence indicates that inorganic mercury (Hg) loadings to Arctic lakes decline with latitude. However, monomethylmercury (MMHg) concentrations in fish and their prey do not decline in a similar fashion, suggesting that higher latitude lakes are more vulnerable to Hg inputs. Preliminary results will be presented from a three-year study (2012-2015) of climate effects on MMHg bioaccumulation in lakes of the eastern Canadian Arctic. We have investigated mercury transport and accumulation processes in lakes and ponds from three study regions along a latitudinal gradient in climate-controlled ecosystem types in the Canadian Arctic, specifically sub-Arctic taiga, Arctic tundra and polar desert. In each water body, we measured key aspects of MMHg bioaccumulation—MMHg bioavailability to benthic food webs and organism growth rates—as well as how watershed characteristics affect the transport of Hg and organic carbon to lakes. Novel approaches were incorporated including the use of passive samplers (Diffusive Gradient in Thin Film samplers or DGTs) to estimate sediment bioavailable MMHg concentrations and tissue RNA content to compare organism short-term growth rates. A comparison of Arctic tundra and sub-Arctic taiga lakes showed that surface water concentrations of MMHg were strongly and positively correlated to total Hg concentrations both within and among study regions, implying strong control of inorganic Hg supply. Sediment concentrations of bioavailable MMHg were highly variable among lakes, although average concentrations were similar between study regions. Local environmental conditions appear to have a strong influence on sediment potential for MMHg supply. Lake-dwelling Arctic char from tundra lakes had similar or higher total Hg concentrations compared with brook trout from sub-Arctic lakes that were exposed to higher water MMHg concentrations. Potential environmental drivers of these patterns will be discussed. This latitudinal study will provide new

Modelling hydrological processes and analysing water-related ecosystem services of Western Siberian lowland basins

NASA Astrophysics Data System (ADS)

Schmalz, Britta; Kiesel, Jens; Kruse, Marion; Pfannerstill, Matthias; Sheludkov, Artyom; Khoroshavin, Vitaliy; Veshkurseva, Tatyana; Müller, Felix; Fohrer, Nicola

2015-04-01

For discussing and planning sustainable land management of river basins, stakeholders need suitable information on spatio-temporal patterns of hydrological components and ecosystem services. The ecosystem services concept, i.e., services provided by ecosystems that contribute to human welfare benefits, contributes comprehensive information for sustainable river management. This study shows an approach to use ecohydrological modelling results for quantifying and assessing water-related ecosystem services in three lowland river basins in Western Siberia, a region which is of global significance in terms of carbon sequestration, agricultural production and biodiversity preservation. Using the ecohydrological model SWAT, the three basins Pyschma (16762 km²), Vagai (3348 km²) and Loktinka (373 km²) were modelled following a gradient from the landscape units taiga, pre-taiga to forest steppe. For a correct representation of the Siberian lowland hydrology, the consideration of snow melt and retention of surface runoff as well as the implementation of a second groundwater aquifer was of great importance. Good to satisfying model performances were obtained for the extreme hydrological conditions. The simulated SWAT output variables of different hydrological processes were used as indicators for the two regulating services water flow and erosion regulation. The model results were translated into a relative ecosystem service valuation scale. The resulting ecosystem service maps show different spatial and seasonal patterns. Although the high resolution modelling results are averaged out within the aggregated relative valuation scale, seasonal differences can be depicted: during snowmelt, low relevant regulation can be determined, especially for water flow regulation, but a very high relevant regulation was calculated for the vegetation period during summer and for the winter period. The SWAT model serves as a suitable quantification method for the assessment of water

[Parasitological factors impeding the transmission of the agent of babesiosis (Babesia microti) to man from the tick Ixodes persulcatus].

PubMed

Korenberg, E I; Nefedova, V V; Kovalevsky, Yu V; Sorokina, Yu V; Gorelova, N B

2015-01-01

Based on the analysis of own and literature data, it is concluded that the following ma- in permanent system of ecologicalarasitological factors prevents the effective vector functions of the tick I. persulcatus in transmission of B. microti: lack of distinct nymphs' anthropophily; small spontaneous invasion of hungry adults; a duration of the parasitic phase in humans is insufficient to complete the sporogonic development, because victims interrupt the phase. Therefore, not excluding the possibility of sporadic babesiosis disea- ses, it can be stated that within the boundaries of a vast territory, where the taiga tick is the only potential source of infection for humans, the B. microti infection has not, and will not reach significant values in infectious pathology.

Succession change of microorganisms on plant waste decomposition in simulation modelling field experiment

NASA Astrophysics Data System (ADS)

Vinogradova, Julia; Perminova, Evgenia; Khabibullina, Fluza; Kovaleva, Vera; Lapteva, Elena

2016-04-01

Plant waste decomposition processes are closely associated with living activity of soil microbiota in aboveground ecosystems. Functional activity of microorganisms and soil invertebrates determines plant material transformation rate whereby changes in plant material chemical composition during destruction - succession change of soil biota. The purpose of the work was revealing the mechanism of microorganisms succession change during plant waste decomposition in middle-taiga green-moss spruce forests and coniferous-deciduous secondary stands formed after earlier cut bilberry spruce forests. The study materials were undisturbed bilberry spruce forest (Sample Plot 1 - SP1) and coniferous-deciduous secondary stands which were formed after tree cutting activities of 2001-2002 (SP2) and 1969 and 1970 (SP3). Plant material decomposition intensity was determined in microcosms isolated into kapron bags with cell size of 1 mm. At SP1 and SP2, test material was living mosses and at SP3 - fallen birch and aspen leaves. Every test material was exposed for 2 years. Destruction rate was calculated as a weight loss for a particular time period. Composition of micromycetes which participated in plant material decomposition was assessed by the method of inoculation of soil extract to Getchinson's medium and acidified Czapek's medium (pH=4.5). Microbe number and biomass was analyzed by the method of luminescent microscopy. Chemical analysis of plant material was done in the certified Ecoanalytical Laboratory of the Institute of Biology Komi SC UrD RAS. Finally, plant material destruction intensity was similar for study plots and comprised 40-44 % weight loss for 2 years. The strongest differences in plant material decomposition rate between undisturbed spruce forests and secondary after-cut stands were observed at first stages of destruction process. In the first exposition year, mineralizing processes were most active in undisturbed spruce forest. Decomposition rate in cuts at that

Expedition to Siberia: A Firsthand Account

NASA Technical Reports Server (NTRS)

Ranson, Jon; Kharuk, Slava; Howl, Joanne

2007-01-01

Nowhere on Earth is warming faster than the Arctic. In northern Siberia, average temperatures have risen 3-5 deg F over the past 30 years, whereas the worldwide average increase in that time is 1 deg F. Betweeen July 28 and August 12, 2007, a small international team of remote sensing and forest ecosystem scientists from NASA and Russia's Academy of Science set off on a three-week scientific expedition through the heart of the remote, wild forests of Siberia. They traveled southward down the Kochechum River observing the gradual transition from tundra to taiga, taking inventory of plant species along the way, and making ground-truth measurements to validate data being collected by several NASA satellites flying 700 kilometers overhead.

[The development and introduction of a rational system for the protection of the personnel in a large enterprise against attack by blood-sucking arthropods in western Siberia].

PubMed

Ermishev, Iu V; Dremova, V P; Stepnov, A P; Semenov, V E

2000-01-01

In the middle Ob River Valley (north and moderate taiga), a large number of bloodsucking dipterans (mosquitoes, blackflies, biting midges, horseflies) are recorded during 90-100 days; the activity of Ixodes persulcatus and their attack on humans are notified during 90-115 days. A package of measures that protect petroleum industrial workers from the attacks of bloodsucking insects and ticks includes the use of protective suits, the treatment of premises with insecticides, the use of repellents, and health education. Protective means for workers should be the items included into the list of expenses on safety measures. Work is done on a cost-accounting principle. The introduced system annually shows a high efficiency (95-98%) in protecting large groups of workers in their working places.

The Tunka-Grande experiment

NASA Astrophysics Data System (ADS)

Monkhoev, R. D.; Budnev, N. M.; Chiavassa, A.; Dyachok, A. N.; Gafarov, A. R.; Gress, O. A.; Gress, T. I.; Grishin, O. G.; Ivanova, A. L.; Kalmykov, N. N.; Kazarina, Yu. A.; Korosteleva, E. E.; Kozhin, V. A.; Kuzmichev, L. A.; Lenok, V. V.; Lubsandorzhiev, B. K.; Lubsandorzhiev, N. B.; Mirgazov, R. R.; Mirzoyan, R.; Osipova, E. A.; Pakhorukov, A. L.; Panasyuk, M. I.; Pankov, L. V.; Poleschuk, V. A.; Popova, E. G.; Postnikov, E. B.; Prosin, V. V.; Ptuskin, V. S.; Pushnin, A. A.; Samoliga, V. S.; Semeney, Y. A.; Sveshnikova, L. G.; Silaev, A. A.; Silaev, A. A., Jr.; Skurikhin, A. V.; Sulakov, V. P.; Tabolenko, V. A.; Voronin, D. M.; Fedorov, O. L.; Spiering, C.; Zagorodnikov, A. V.; Zhurov, D. P.; Zurbanov, V. L.

2017-06-01

The investigation of energy spectrum and mass composition of primary cosmic rays in the energy range 1016-1018 eV and the search for diffuse cosmic gamma rays are of the great interest for understanding mechanisms and nature of high-energy particle sources, the problem of great importance in modern astrophysics. Tunka-Grande scintillator array is a part of the experimental complex TAIGA (Tunka Advanced Instrument for Cosmic Ray and Gamma Astronomy) which is located in the Tunka Valley, about 50 km from Lake Baikal. The purpose of this array is the study of diffuse gamma rays and cosmic rays of ultra-high energies by detecting extensive air showers. We describe the design, specifications of the read-out, data acquisition (DAQ) and control systems of the array.

[Annual production of moss layer in dark coniferous forests of Ket-Chulym Forest District (by the example of Moss Hylocomium splendens)].

PubMed

Koshurnikova, N N

2007-01-01

The biological production of the moss layer was analyzed in dark coniferous stands in progressive succession in the southern taiga in West Siberia. The rate of organic matter production by mosses changed from 15-22.2 g/(m2 y) in 50-90-year-old fir forests to 51.6 g/(m2 y) in 170-year-old mixed Siberian pine-spruce-fir stands. In forest phytocenosis that were formed with species replacement (after cuttings with understory clearing), the annual moss production (net primary production) ranged from 2.8 to 20.6 g/(m2 y). The annual moss cover production amounted to 35-36% of the moss photosynthetic biomass irrespective of the type of native stand progressive succession and the stand age.

Molecular and structural characterization of novel cystatins from the taiga tick Ixodes persulcatus.

PubMed

Rangel, Carolina K; Parizi, Luís F; Sabadin, Gabriela A; Costa, Evenilton P; Romeiro, Nelilma C; Isezaki, Masayoshi; Githaka, Naftaly W; Seixas, Adriana; Logullo, Carlos; Konnai, Satoru; Ohashi, Kazuhiko; da Silva Vaz, Itabajara

2017-03-01

Cystatins are cysteine peptidase inhibitors that in ticks mediate processes such as blood feeding and digestion. The ixodid tick Ixodes persulcatus is endemic to the Eurasia, where it is the principal vector of Lyme borreliosis. To date, no I. persulcatus cystatin has been characterized. In the present work, we describe three novel cystatins from I. persulcatus, named JpIpcys2a, JpIpcys2b and JpIpcys2c. In addition, the potential of tick cystatins as cross-protective antigens was evaluated by vaccination of hamsters using BrBmcys2c, a cystatin from Rhipicephalus microplus, against I. persulcatus infestation. Sequence analysis showed that motifs that are characteristic of cystatins type 2 are fully conserved in JpIpcys2b, while mutations are present in both JpIpcys2a and JpIpcys2c. Protein-protein docking simulations further revealed that JpIpcys2a, JpIpcys2b and JpIpcys2c showed conserved binding sites to human cathepsins L, all of them covering the active site cleft. Cystatin transcripts were detected in different I. persulcatus tissues and instars, showing their ubiquitous expression during I. persulcatus development. Serological analysis showed that although hamsters immunized with BrBmcys2c developed a humoral immune response, this response was not adequate to protect against a heterologous challenge with I. persulcatus adult ticks. The lack of cross-protection provided by BrBmcys2c immunization is perhaps linked to the fact that cystatins cluster into multigene protein families that are expressed differentially and exhibit functional redundancy. How to target such small proteins that are secreted in low quantities remains a challenge in the development of suitable anti-tick vaccine antigens. Copyright © 2017 Elsevier GmbH. All rights reserved.

Identification and characterization of antimicrobial peptide, defensin, in the taiga tick, Ixodes persulcatus.

PubMed

Saito, Y; Konnai, S; Yamada, S; Imamura, S; Nishikado, H; Ito, T; Onuma, M; Ohashi, K

2009-08-01

Ixodes persulcatus is the primary vector for human tick-borne diseases in Japan. A cDNA library was constructed from whole body homogenates of fed nymphs of I. persulcatus. From this library, one cDNA encoding defensin-like antimicrobial peptide was identified. The amino-acid sequence showed high similarity to those of the defensins of other ticks and arthropods. I. persulcatus defensin mRNA transcripts were detected at all life cycle stages of fed ticks and found to be predominantly expressed in the midguts of adult female ticks, but not in the salivary glands, a finding corroborated by Western blotting analysis. To investigate the function of I. persulcatus defensin, we examined its antibacterial activity by evaluation of growth of several bacterial strains in the presence of the synthetic peptide. The defensin from I. persulcatus markedly inhibited the growth of Gram-positive bacteria including Staphylococcus aureus, Bacillus subtilis and Corynebacterium renale, but not Gram-negative bacteria except Escherichia coli O157. In conclusion, these results suggest that I. persulcatus defensin may be playing a significant role in the defence against microbes from bloodmeals.

Fire, grazing history, lichen abundance, and winter distribution of caribou in Alaska's taiga

USGS Publications Warehouse

Collins, William B.; Dale, Bruce W.; Adams, Layne G.; McElwain, Darien E.; Joly, Kyle

2011-01-01

In the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with >20% lichen cover (P < 0.001), greater than 1,250 kg/ha (P < 0.001) forage lichen biomass and stands older than 80 yr postfire (P < 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after ≥60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis‐idaea) were necessary for predicting caribou use of winter range.

(abstract) Monitoring the Freeze/Thaw Transitions in Taiga Forests Using ERS-1 SAR

NASA Technical Reports Server (NTRS)

Rignot, E.; Williams, C.; Donald, K. Mc; Way, J. B.; Zimmerman, R.; Viereck, L.

1994-01-01

Automated recording stations have been installed at the Bonanza Creek Experimental Forest, a Long Term Ecological Research (LTER) site located near Fairbanks, Alaska, in a forest stand of the Tanana River floodplain underlain by discontinuous permafrost. These stations provide a continuous record of dielectric constant and temperature of tree trunks, and soil moisture and temperature profiles down to the root zone. Along with the weather stations deployed at the same location, these measurements provide a continuous record of the environmental and phenologic conditions of the forest during a complete seasonal cycle. At the same time, ERS-1 SAR imaged the study site repeatedly from space to provide radar backscatter measurements of the forest approximately three times a month. Here, we examine the temporal dynamic of ERS-1 SAR measurements in relation with the changing environmental and phenologic state of the forest canopy and of the forest ground layers during the winter/spring and fall/winter transitions of 1992 and 1993. During these transitions, we examine whether changes in radar backscatter observed by ERS-1 may be related to freezing or thawing of the soil and vegetation in order to determine the start and end of the growing season for the forest. The results of this analysis are used in turn to determine whether similar changes are observed over larger regions. Mosaics of SAR data generated along three different North-South Alaskan ERS-1 transects that intercept with our study site are used in combination with hourly air temperature and daily precipitation rates gathered at airport weather stations by the National Weather Service. Results obtained using ERS-1 data collected from January 1992 to mid-1993 will be discussed.

The influence of plant communities on postagrogenic soils in the middle taiga zone.

NASA Astrophysics Data System (ADS)

Churilin, Nikita; Churilina, Alexandra; Chizhikova, Natalia; Varlamov, Evgeny

2016-04-01

At the present time there are many abandoned postagrogenic croplands in Russia. These lands are gradually involved in natural plant succession, which has affect on the properties of the soil. Therefore, the study of these soils is one of the important trends in the Russian soil science. The aim of the study was to identify possible trends in soil changes after a long anthropogenic impact on a base of morphological, chemical and some physical properties of postagrogenic soils under different plant communities. Soils were sampled in the south of Arkhangelsk region, Ustyansky district, near Akichkin Pochinok village. Soils are formed on clay moraine of Moscow glaciation with klastolits. All soil profiles were dug on interfluve. We determined chemical composition (pH, CaCO3%, organic carbon, CEC, F2O3 (Mer-Jackson), NPK), physical characteristics (particle size distribution, bulk density of the soil) and XRD of <1μm, 1-5μm, 5-10μm fractions from soils. We selected 4 plant communities on different stages of succession: upland meadow with domination of sod grasses (Phleum pratense, Agrostis tenuis), 16 years old birch forest where dominatants are herbaceous plants such as Poa sp., Chamerion angustiflium, Agrostis tenuis, 16 years old spruce forest with no herbaceous vegetation and 70 years old bilberry spruce forest with domination of Vaccinium myrtillus and Vaccinium vitis-idaea. To study postagrogenic soils we made 4 soil profiles under these plant communities. All profiles have evidence of anthraquic horizon and they have plough pan on a depth of 20-24 cm (confirmed by bulk density). The plowed horizon is better expressed in soils under the meadow. All 4 soils are characterized by presence of Fe-Mn segregations throughout the profiles, particle size distribution heaving to the lower horizon and residual albic horizon. We identified following soils: Albic Dystric Retisol (Cutanic Abrubptic Loamic) under the old spruce, Dystric Retisol (Cutanic Loamic Anthraquic) in young spruce, Glossic Albic Dystric Retisol (Cutanic Loamic Anthraquic) in young birch forest and Dystric Retisol (Loamic Abruptic Anthraquic) under upland meadow. We found a correlation between amount of clay fraction in upper horizons (<20 cm) of these soils and crown density: the amount of clay increases with density of branches. This trend can be explained by the fact that amount of precipitation on the surface of the soil decreases with crown density, therefore clay doesn't migrate to the underlying horizons in the soil. Over time, acid aqueous solution can influence on process of clay fraction redistribution, so it explains the reduction of clay content in the old spruce forest and well-defined albic horizon. The results of chemical analyses showed that pH of these soils varies between 3 and 4. In all soils we can see illuvial accumulation of P2O5, exchangeable bases, K2O, Fe2O3. It was also shown that carbonates are present in horizons close to the subsoil, which content is less than 1%.

A thirty year, fine-scale, characterization of area burned in Canadian forests shows evidence of regionally increasing trends in the last decade

PubMed Central

2018-01-01

Fire as a dominant disturbance has profound implications on the terrestrial carbon cycle. We present the first ever multi-decadal, spatially-explicit, 30 meter assessment of fire regimes across the forested ecoregions of Canada at an annual time-step. From 1985 to 2015, 51 Mha burned, impacting over 6.5% of forested ecosystems. Mean annual area burned was 1,651,818 ha and varied markedly (σ = 1,116,119), with 25% of the total area burned occurring in three years: 1989, 1995, and 2015. Boreal forest types contained 98% of the total area burned, with the conifer-dominated Boreal Shield containing one-third of all burned area. While results confirm no significant national trend in burned area for the period of 1985 to 2015, a significant national increasing trend (α = 0.05) of 11% per year was evident for the past decade (2006 to 2015). Regionally, a significant increasing trend in total burned area from 1985 to 2015 was observed in the Montane Cordillera (2.4% increase per year), while the Taiga Plains and Taiga Shield West displayed significant increasing trends from 2006 to 2015 (26.1% and 12.7% increases per year, respectively). The Atlantic Maritime, which had the lowest burned area of all ecozones (0.01% burned per year), was the only ecozone to display a significant negative trend (2.4% decrease per year) from 1985 to 2015. Given the century-long fire return intervals in many of these ecozones, and large annual variability in burned area, short-term trends need to be interpreted with caution. Additional interpretive cautions are related to year used for trend initiation and the nature and extents of spatial regionalizations used for summarizing findings. The results of our analysis provide a baseline for monitoring future national and regional trends in burned area and offer spatially and temporally detailed insights to inform science, policy, and management. PMID:29787562

Unimodal Latitudinal Pattern of Land-Snail Species Richness across Northern Eurasian Lowlands

PubMed Central

Horsák, Michal; Chytrý, Milan

2014-01-01

Large-scale patterns of species richness and their causes are still poorly understood for most terrestrial invertebrates, although invertebrates can add important insights into the mechanisms that generate regional and global biodiversity patterns. Here we explore the general plausibility of the climate-based “water-energy dynamics” hypothesis using the latitudinal pattern of land-snail species richness across extensive topographically homogeneous lowlands of northern Eurasia. We established a 1480-km long latitudinal transect across the Western Siberian Plain (Russia) from the Russia-Kazakhstan border (54.5°N) to the Arctic Ocean (67.5°N), crossing eight latitudinal vegetation zones: steppe, forest-steppe, subtaiga, southern, middle and northern taiga, forest-tundra, and tundra. We sampled snails in forests and open habitats each half-degree of latitude and used generalized linear models to relate snail species richness to climatic variables and soil calcium content measured in situ. Contrary to the classical prediction of latitudinal biodiversity decrease, we found a striking unimodal pattern of snail species richness peaking in the subtaiga and southern-taiga zones between 57 and 59°N. The main south-to-north interchange of the two principal diversity constraints, i.e. drought stress vs. cold stress, explained most of the variance in the latitudinal diversity pattern. Water balance, calculated as annual precipitation minus potential evapotranspiration, was a single variable that could explain 81.7% of the variance in species richness. Our data suggest that the “water-energy dynamics” hypothesis can apply not only at the global scale but also at subcontinental scales of higher latitudes, as water availability was found to be the primary limiting factor also in this extratropical region with summer-warm and dry climate. A narrow zone with a sharp south-to-north switch in the two main diversity constraints seems to constitute the dominant and general

Methane emissions from western Canadian peatland lakes: assessing interactive effects of groundwater connectivity and permafrost thaw

NASA Astrophysics Data System (ADS)

Kuhn, M. A.; Riechert, C.; Estop Aragones, C.; Broder, T.; Bastviken, D.; Knorr, K. H.; Olefeldt, D.

2017-12-01

Rising temperatures and the submergence of recently thawed permafrost into lakes has been identified as a major driver of methane (CH4) emissions in northern regions. Lakes on the vast Taiga Plains in western Canada represent a vital unknown with respect to CH4 fluxes and their sensitivity to permafrost thaw. The Taiga Plains has several characteristics that could influence magnitude and controls on lake CH4 emissions in comparison to other regions, including high soil organic carbon stores, distinct permafrost history, and complex groundwater interactions that influence availability of terminal electron acceptor concentrations among lakes. The goal of this research is to describe the similarities and differences in processes governing lake CH4 emissions between western Canada and other northern regions. We carried out biweekly diffusive and ebullition flux measurements and monitored sediment redox profiles from two lakes near the border between Alberta and the Northwest Territories. The two lakes differ in contributions of surface water and groundwater inputs, respectively. Floating chamber-based fluxes were measured leading from the edges to the centers of the lakes from ice-out in early May until ice-cover in the fall. Preliminary redox profile analyses suggest the groundwater-fed lake has extremely high concentrations of sulfides (>200 µmol L-1) down to a depth of 30 cm, while the surface water lake has little to no sulfide, but high concentrations of reduced iron (>200 µmol L-1 ). Despite high sulfide concentrations in the sediments, the groundwater-fed lake had generally higher diffusive fluxes compared to the surface water lake, but there were no differences between the center and along the actively collapsing thermokarst edges. However, ebullition fluxes were highest from a recently thawed lake edge compared to the center of the lake and stable, non-thaw influenced edges. The results of this project will help improve current regional CH4 models by

Northern Peatland Shifts Under Changing Climate and Their Impact on Permafrost

NASA Astrophysics Data System (ADS)

Shur, Y.; Jorgenson, T.; Kanevskiy, M. Z.

2014-12-01

Formation of peatlands depends primarily on climate and its interactions with hydrology, soil thermal regimes, plant composition, and nutrients. A water balance with precipitation exceeding evaporation is necessary for their formation. The rate of peat accumulation also greatly depends on thermal resources. The prominent impact of the water balance and temperature on peatland formation is evident in the West Siberia Lowland. The rate of peat accumulation steadily increases from arctic tundra to moss tundra, to forest tundra, to northern taiga, and to southern taiga. This increase is a result in increase in air temperature and length of the growing season because all of these zones have water balance favorable for peat formation. Further to south, evaporation prevails over precipitation and peat formation occurs only in isolated areas. Climate change will redefine geographical distribution of climatic and vegetation zones. It is predicted that in arctic and subarctic regions the difference between precipitation and evaporation will increase and as a result these regions will remain favorable to peat accumulation. With increase of thermal resources, the rate of peat accumulation will also increase. The Alaska Arctic Coastal Plain is of a special interest because it has thousands of shallow lakes, which due to warming climate would shift from open waterbodies to peatlands through shoreline paludification and infilling. The accumulation of organic matter will likely turn open water into shore fens and bogs, and eventually to peat plateaus, as is occurring in many boreal landscapes. Expected impact on permafrost in arctic and subarctic regions will include rise of the permafrost table, thickening of the ice-rich intermediate layer with ataxitic (suspended) cryostructure, and replacement of frost boils with earth hummocks. In the contemporary continuous permafrost zone, permafrost formed as climate-driven will be transformed into climate-driven ecosystem protected

Spatial distribution of young forests and carbon fluxes within recent disturbances in Russia.

PubMed

Loboda, Tatiana V; Chen, Dong

2017-01-01

Forest stand age plays a major role in regulating carbon fluxes in boreal and temperate ecosystems. Young boreal forests represent a relatively small but persistent source of carbon to the atmosphere over 30 years after disturbance, while temperate forests switch from a substantial source over the first 10 years to a notable sink until they reach maturity. Russian forests are the largest contiguous forest belt in the world that accounts for 17% of the global forest cover; however, despite its critical role in controlling global carbon cycle, little is known about spatial patterns of young forest distribution across Russia as a whole, particularly before the year 2000. Here, we present a map of young (0-27 years of age) forests, where 12- to 27-year-old forests were modeled from the single-date 500 m satellite record and augmented with the 0- to 11-year-old forest map aggregated from the 30 m resolution contemporary record between 2001 and 2012. The map captures the distribution of forests with the overall accuracy exceeding 85% within three largest bioclimatic vegetation zones (northern, middle, and southern taiga), although mapping accuracy for disturbed classes was generally low (the highest of 31% for user's and producer's accuracy for the 12-27 age class and the maximum of 74% for user's and 32% for producer's accuracy for the 0-11 age class). The results show that 75.5 ± 17.6 Mha (roughly 9%) of Russian forests were younger than 30 years of age at the end of 2012. The majority of these 47 ± 4.7 Mha (62%) were distributed across the middle taiga bioclimatic zone. Based on the published estimates of net ecosystem production (NEP) and the produced map of young forests, this study estimates that young Russian forests represent a total sink of carbon at the rate of 1.26 Tg C yr -1 . © 2016 John Wiley & Sons Ltd.

Threshold loss of discontinuous permafrost and landscape evolution.

PubMed

Chasmer, Laura; Hopkinson, Chris

2017-07-01

This study demonstrates linkages between the 1997/1998 El Niño/Southern Oscillation index and a threshold shift to increased permafrost loss within a southern Taiga Plains watershed, Northwest Territories, Canada. Three-dimensional contraction of permafrost plateaus and changes in vegetation structural characteristics are determined from multitemporal airborne Light Detection And Ranging (LiDAR) surveys in 2008, 2011 and 2015. Morphological changes in permafrost cover are compared with optical image analogues from 1970, 1977, 2000 and 2008 and time-series hydro-climate data. Results demonstrate that significant changes in air temperature, precipitation, runoff and a shortening of the snow-covered season by 35 days (1998-2014) and 50 days (1998 only) occurred after 1997. The albedo reduction associated with 35 and 50 days less snow cover leads to increases in shortwave energy receipt during the active thaw period of ~12% (3% annually) and ~16% (5% annually), respectively. From 2000 to 2015, sporadic permafrost loss accelerated from 0.19% (of total basin area) per year between 1970 and 2000 to 0.58% per year from 2000 to 2015, with a projected total loss of permafrost by ~2044. From ~1997 to 2011, we observe a corresponding shift to increased runoff ratio. However, observed increases in the proportion of snow precipitation and the volumetric contribution of permafrost loss to runoff post-1997 (0.6-6.4% per year) cannot fully explain this shift. This suggests increases in drainage efficiency and possible losses from long-term groundwater storage as a result of subtle terrain morphological and soil zone hydraulic conductivity changes. These hydrological changes appear coincident with high vegetation mortality at plateau margins combined with succession-related canopy growth in some bog and fen areas, which are presumed to be drying. Similar changes in runoff response were observed at adjacent Birch, Trout and Jean Marie River watersheds indicating that observations

A thirty year, fine-scale, characterization of area burned in Canadian forests shows evidence of regionally increasing trends in the last decade.

PubMed

Coops, Nicholas C; Hermosilla, Txomin; Wulder, Michael A; White, Joanne C; Bolton, Douglas K

2018-01-01

Fire as a dominant disturbance has profound implications on the terrestrial carbon cycle. We present the first ever multi-decadal, spatially-explicit, 30 meter assessment of fire regimes across the forested ecoregions of Canada at an annual time-step. From 1985 to 2015, 51 Mha burned, impacting over 6.5% of forested ecosystems. Mean annual area burned was 1,651,818 ha and varied markedly (σ = 1,116,119), with 25% of the total area burned occurring in three years: 1989, 1995, and 2015. Boreal forest types contained 98% of the total area burned, with the conifer-dominated Boreal Shield containing one-third of all burned area. While results confirm no significant national trend in burned area for the period of 1985 to 2015, a significant national increasing trend (α = 0.05) of 11% per year was evident for the past decade (2006 to 2015). Regionally, a significant increasing trend in total burned area from 1985 to 2015 was observed in the Montane Cordillera (2.4% increase per year), while the Taiga Plains and Taiga Shield West displayed significant increasing trends from 2006 to 2015 (26.1% and 12.7% increases per year, respectively). The Atlantic Maritime, which had the lowest burned area of all ecozones (0.01% burned per year), was the only ecozone to display a significant negative trend (2.4% decrease per year) from 1985 to 2015. Given the century-long fire return intervals in many of these ecozones, and large annual variability in burned area, short-term trends need to be interpreted with caution. Additional interpretive cautions are related to year used for trend initiation and the nature and extents of spatial regionalizations used for summarizing findings. The results of our analysis provide a baseline for monitoring future national and regional trends in burned area and offer spatially and temporally detailed insights to inform science, policy, and management.

Summer foods of American widgeon, mallards, and a green-winged teal near Great Slave Lake, N.W.T

USGS Publications Warehouse

Bartonek, J.C.

1972-01-01

Foods found in three species of dabbling ducks collected during summer from bog ponds, and sedge pools in taiga on the north side of Great Slave Lake, Northwest Territories, are described. Animal material in the esophageal contents of 10 adult American Widgeons (Mareca americana) averaged 31 i?? 34 per cent (P<0.05) by volume. A significantly higher percentage of animal material was found in Class I and II widgeon ducklings (66 i?? 22 per cent) than in Class IIIa ducklings and flying juveniles (12 i?? 20 per cent) of this species. Animal material comprised 87 i?? 35 per cent of esophageal contents from five Class II and flying juvenile Mallards (Anas platyrhynchos) and 100 per cent of that from an adult female Green-winged Teal (A. carolinensis).

Isotopic investigation of rivers runoff in glaciated regions of the central Asian arid highlands (southeastern Altai)

NASA Astrophysics Data System (ADS)

Bantcev, Dmitrii; Ganushkin, Dmitriy; Ekaykin, Alexey; Chistyakov, Kirill

2017-04-01

Stable isotopes investigations were carried out during fieldwork in glacier basins of the Mongun-Taiga (southwestern Tuva) and Tsambagarav (northwestern Mongolia) mountain massifs in July, 2016. These Arid highlands are problematic in the context of provision of water resources, and glaciers here play a large part in nourishment of the rivers. Concentrations of the oxygen 18, deuterium and the mineralization were measured in the samples of meltwater, precipitation, water from streams, ice and snow. Sable isotope method was used for separation of the glacier runoff. Average isotopic characteristics for different water sources, such as glacier ice, snow patches and precipitation, were calculated and the contribution of these sources in total runoff was valued. Isotopic method was also used for estimation of contribution of buried ice meltwater from rock glaciers ice cores.

Migratory birds are the source of highly toxic organic pollutants for indigenous people in the Russian Arctic

NASA Astrophysics Data System (ADS)

Pesiakova, A. A.; Gusakova, E. V.; Trofimova, A. N.; Sorokina, T. Yu

2018-01-01

Polychlorinated biphenyls are highly toxic organic contaminants. Due to their chemical properties they had wide application in industry and agriculture in the 20th century. In 2001 the production of PCBs has been prohibited almost worldwide. Environmental contamination has been found in soils, water, and air where there were PCB production sites. They have been detected in fish, birds and animals of migratory species, retaining transboarding transfer. Several migratory species of birds (Taiga bean goose, greater white-fronted goose, lesser white fronted goose and barnacle goose) are a diet for indigenous people. PCBs accumulating in the human body affect all systems and organs. This article reviews the contribution of migratory bird species in transboarding transfer of highly toxic contaminants in the Nenets Autonomous Area, Kolguev island (Russian Arctic).

Whole-genome sequencing of Borrelia garinii BgVir, isolated from Taiga ticks (Ixodes persulcatus).

PubMed

Brenner, Evgeniy V; Kurilshikov, Alexander M; Stronin, Oleg V; Fomenko, Nataliya V

2012-10-01

Most Lyme borreliosis cases in Russia result from Borrelia garinii NT29 group infection. Borrelias of this group circulate exclusively in Ixodes persulcatus ticks, which are seldom found beyond Russia and the far east. Here we report the whole-genome sequence of Borrelia garinii BgVir isolated from an I. persulcatus female.

Diversity of the soil biota in burned areas of southern taiga forests (Tver oblast)

NASA Astrophysics Data System (ADS)

Gongalsky, K. B.; Zaitsev, A. S.; Korobushkin, D. I.; Saifutdinov, R. A.; Yazrikova, T. E.; Benediktova, A. I.; Gorbunova, A. Yu.; Gorshkova, I. A.; Butenko, K. O.; Kosina, N. V.; Lapygina, E. V.; Kuznetsova, D. M.; Rakhleeva, A. A.; Shakhab, S. V.

2016-03-01

Relations between soil biota diversity and its contribution to the performance of some ecosystem functions were assessed based on the results obtained in undisturbed and burned spruce forests near the Central Forest Nature Biosphere Reserve (Tver oblast). In August 2014, in two 4-year-old burned areas, abiotic parameters of the soils, indicators of the state of the microbial communities, the number, taxonomic diversity, and the abundance of the main groups of soil invertebrates (testate amoebae, nematodes, enchytraeids, mites, collembolans, and the mesofauna as a whole) were determined. In the soils of the burned areas, higher CO2, CH4, and N2O emissions were observed. The number of bacterial cells remained similar, and the total length of active mycelium was not significantly different. All this implies a certain intensification of biogenic processes promoting the mobilization of carbon and nitrogen after fire. The number of most of the groups of soil animals was lower (not always significantly) in the burned area than that in the soils of the undisturbed forests. The changes in the taxonomic diversity were specific for each taxon studied. Overall, the diversity of invertebrates was related to the litter thickness. However, the high taxonomic diversity of soil fauna did not always correspond to the active functioning of the ecosystem. Thus, for some taxa, a quite close correlation was found, for instance, between the total number of species (of testate amoebae in particular) and the berry crop, as well as between the soil mesofauna population and the dead wood stock. The total diversity of the investigated taxa included in the detrital trophic web was the most reliable indicator of the carbon stock in the burned areas.

New perspectives on the Popigai impact structure

NASA Technical Reports Server (NTRS)

Garvin, J. B.; Deino, A. L.

1992-01-01

The record of large-scale cratering on Earth is scant, and the only currently 'proven' 100-km-class impact structure known to have formed within the Cenozoic is Popigai, located in the Siberian Arctic at 71.5 deg N, 111 deg E. Popigai is clearly a multiringed impact basin formed within the crystalline shield rocks (Anabar) and platform sediments of the Siberian taiga, and estimates of the volume of preserved impact melt typically exceed 1700 cu km, which is within a factor of 2-3 of what would be predicted using scaling relationships. We present the preliminary results of an analysis of the present-day topography of the Popigai structure, together with refined absolute age estimates, in order to reconstruct the pre-erosional morphology of the basin, as well as to quantify the erosion or sediment infill rates in the Popigai region.

OF BELGOROD PROVINCE].

PubMed

Prisniy, Yu A

2016-01-01

The article provides a list of 30 species of the family Tabanidae, recorded in Belgorod Province. Forest and forest-steppe species dominate (60 %), being found at edges of oak forests, deciduous and mixed forests, and in mesophytic meadows. These species are distributed over the entire area of the region. The fraction of taiga-forest species in the region is small (10 %). These species are found in western and northern areas where large forests and sphagnum bogs are present. The fraction of steppe species constitutes 13.3 %, these species are found mainly in eastern and south-eastern parts of the Province, where areas of steppe and cretaceous outcrops are found. Desert species (6.7 %) and a single Mediterranean coastal species were also recorded in the region. Mass emergence of horseflies in Belgorod Province begins in June and lasts until mid-August.

Revealing the Hyperdiverse Mite Fauna of Subarctic Canada through DNA Barcoding

PubMed Central

Young, Monica R.; Behan-Pelletier, Valerie M.; Hebert, Paul D. N.

2012-01-01

Although mites are one of the most abundant and diverse groups of arthropods, they are rarely targeted for detailed biodiversity surveys due to taxonomic constraints. We address this gap through DNA barcoding, evaluating acarine diversity at Churchill, Manitoba, a site on the tundra-taiga transition. Barcode analysis of 6279 specimens revealed nearly 900 presumptive species of mites with high species turnover between substrates and between forested and non-forested sites. Accumulation curves have not reached an asymptote for any of the three mite orders investigated, and estimates suggest that more than 1200 species of Acari occur at this locality. The coupling of DNA barcode results with taxonomic assignments revealed that Trombidiformes compose 49% of the fauna, a larger fraction than expected based on prior studies. This investigation demonstrates the efficacy of DNA barcoding in facilitating biodiversity assessments of hyperdiverse taxa. PMID:23133656

[Morphophysiological and Behavioral Adaptations of Elk to Wintering].

PubMed

Glushkov, V M; Kuznetsov, G V

2015-01-01

This paper studies morphometric parameters (body weight, weight of internal organs, body size, etc.) in 170 elk of various sex and age obtained in the Vyatka taiga area in winter. A number of physiological parameters (specific metabolism and thermal conductivity, heat loss rate, etc.) characterizing the metabolic rate and energy balance in the body were calculated for model animals (calf, male, and female). It is noted that in the transition from the first to the second half of winter the specific metabolism in model animals decreased from 20.6, 16.9, and 15.9 to 18.7, 15.4, and 14.5 kcal/(kg day), respectively. It is shown that changes in the rhythm of motor activity of elk are synchronized with the daily air temperature and the maximum flight distance depends on the amount of energy received by the body with food.

Century-scale climate-driven vegetation and environmental dynamics in southern Siberia during the last 47 kyr

NASA Astrophysics Data System (ADS)

Tarasov, Pavel; Bezrukova, Elena; Solovieva, Nadia; Riedel, Frank

2010-05-01

Radiocarbon-dated pollen and diatom records from Lake Kotokel in southern Siberia are used to reconstruct the environmental history of the area since ~47 kyr BP. Pollen data and reconstructed biome scores suggest predominance of a tundra-steppe vegetation and variable woody cover (5-20%) between ~47-30 kyr BP, indicating generally a harsh and unstable climate during this interval, conventionally regarded as the MIS3 interstadial. The short-term climate amelioration episodes in the glacial part of the records are marked by the peaks in taiga and corresponding minima in steppe biome scores and appear synchronously with the hemispheric temperature and precipitation changes recorded in the Greenland ice cores and Chinese stalagmites. The interval ~30-24 kyr BP was probably the driest and coldest of the whole record, as indicated by highest scores for steppe biome, woody coverage <5%, absence of diatoms and reduced size of the lake. A slight amelioration of the regional climate ~24-22 kyr BP was followed by a shorter than the previous and less pronounced deterioration phase. After 14.7 kyr BP the climate became warmer and wetter than ever during ~47-14.7 kyr BP, resulting in the deepening of the lake and increase in the woody coverage to 20-30% ~14.5-14 kyr and ~13.3-12.8 kyr BP. These two intervals correspond to the Meiendorf and Allerød interstadials, which until now were interpreted as part of the undifferentiated Bølling/Allerød interstadial complex in the Lake Baikal region. The increase in tundra biome scores and pronounced change in the diatom composition allow (for the first time) the unambiguous identification of the Younger Dryas (YD) in the region ~12.7-11.65 kyr BP, suggesting the synchronous onset of the YD and the Holocene interglacial across Eurasia. The maximal spread of the taiga communities in the region is associated with a warmer and wetter climate than the present prior to ~7 kyr BP. This was followed by a wide spread of Scots pine, indicating

Trends in the normalized difference vegetation index (NDVI) associated with urban development in arctic and subarctic Western Siberia

NASA Astrophysics Data System (ADS)

Outten, S.; Miles, V.; Ezau, I.

2015-12-01

Changes in normalized difference vegetation index (NDVI) in the high Arctic have been reliably documented, with widespread "greening" (increase in NDVI), specifically along the northern rim of Eurasia and Alaska. Whereas in West Siberia south of 65N, widespread "browning" (decrease in NDVI) has been noted, although the causes remain largely unclear. In this study we report results of statistical analysis of the spatial and temporal changes in NDVI around 28 major urban areas in the arctic and subarctic Western Siberia. Exploration and exploitation of oil and gas reserves has led to rapid industrialization and urban development in the region. This development has significant impact on the environment and particularly in the vegetation cover in and around the urbanized areas. The analysis is based on 15 years (2000-2014) of high-resolution (250 m) Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired for summer months (June through August) over the entire arctic and subarctic Western Siberian region. The analysis shows that the NDVI background trends are generally in agreement with the trends reported in previous coarse-resolution NDVI studies. Our study reveals greening over the arctic (tundra and tundra-forest) part of the region. Simultaneously, the southern (boreal taiga forest) part is browning, with the more densely vegetation areas or areas with highest NDVI, particularly along Ob River showing strong negative trend. The unexpected and interesting finding of the study is statistically robust indication of the accelerated increase of NDVI ("greening") in the older urban areas. Many Siberian cities become greener even against the decrease in the NDVI background. Moreover, interannual variations of urban NDVI are not coherent with the NDVI background variability. We also find that in tundra zones, NDVI values are higher in a 5-10 km buffer zone around the city edge than in rural areas (40 km distance from the city edge), and in taiga in a 5-10 km

Molecular identification and expression analysis of lipocalins from blood feeding taiga tick, Ixodes persulcatus Schulze.

PubMed

Konnai, Satoru; Nishikado, Hideto; Yamada, Shinji; Imamura, Saiki; Ito, Takuya; Onuma, Misao; Murata, Shiro; Ohashi, Kazuhiko

2011-02-01

Lipocalins have been known for their several biological activities in blood-sucking arthropods. Recently, the identification and characterization of lipocalins from Ixodes ricinus (LIRs) have been reported and functions of lipocalins are well documented. In this study, we have characterized four Ixodes persulcatus lipocalins that were discovered while analyzing I. persulcatus tick salivary gland EST library. We show that the four I. persulcatus lipocalins, here after named LIPERs (lipocalin from I. persulcatus) are 28.8-94.4% identical to LIRs from I. ricinus. Reverse transcriptase-PCR analysis revealed that lipocalin genes were expressed specifically in the salivary glands throughout life cycle stages of the ticks and were up-regulated by blood feeding. The specific expressions were also confirmed by Western blotting analysis. Furthermore, to investigate whether native lipocalins are secreted into the host during tick feeding, the reactivity of anti-serum raised against saliva of adult ticks to recombinant lipocalins was tested by Western blotting. The lipocalins are potentially secreted into the host during tick feeding as revealed by specific reactivity of recombinant lipocalins with mouse antibodies to I. persulcatus tick saliva. Preliminary vaccination of mice with recombinant lipocalins elicited that period to reach engorgement was significantly delayed and the engorgement weight was significantly reduced as compared to the control. Further elucidation of the biological functions of LIPERs are required to fully understand the pathways involved in the modulation of host immune responses. Copyright © 2010 Elsevier Inc. All rights reserved.

Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula

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

Nikonov, V.V.

1981-01-01

The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).

Carbon budget of oligotrophic mires in the Southern Taiga of Western Siberia under anthropogenic impact

NASA Astrophysics Data System (ADS)

Golovatskaya, Eugenia; Dyukarev, Egor

2010-05-01

Role of peatlands in the global greenhouse gases budget is highly relevant. According to present estimates peatlands in undisturbed conditions act as a sink for the atmospheric carbon. Anthropogenic impact on peatlands (melioration, changes in land use, influence of underground water catchments) results in water table lowering, changing in vegetation cover, and degradation of peat deposit. Peatlands could provide a significant positive feedback for climate changes if warming and peatlands drying stimulates bulk soil organic matter decomposition which enhances CO2 release to the atmosphere. Western Siberian peatlands usually represented big bog massifs. Big peatlands have higher stability to external influence. Small peatlands have all signs of big bogs but react on changes in environmental variables more quickly. The present study is devoted to investigation of primary carbon fluxes (CO2 emission and net primary productivity) and carbon balance at oligotrophic bogs in native condition (key area "Bakchar") and under anthropogenic impact (key area "Ob'-Tom'"). The key area "Bakchar" is located between the Iksa and Bakchar rivers (56o58`N 82o36`E) at the Bakcharskoe bog (area 1400 km2). The key area "Ob'-Tom'"is located in the northern part of Ob' and Tom' interfluve (56o21`N 82o31`E). The "Bakchar" key area includes the following ecosystems: pine- shrub-sphagnum community, a similar community with stunted (low) pine trees, and sedge-sphagnum fen. Two small peatlands were studied at Ob' and Tom' interfluve. Kirsanovskoe bog includes pine- shrub-sphagnum community and sedge fen. Timiryazevskoe bog was represented by pine- shrub-sphagnum (TPSS) community and sedge fen. An infrared gas analyzer OPTOGAS 500.4 (OPTEC Corp., St.-Petersburg, Russia) attached to a static opaque plastic been used for carbon dioxide emission measurements. The net primary productivity was measured by clipping method (Golovatskaya and Dyukarev, Plant Soil 2009). Peatlands at "Ob'-Tom'" key area are under impact of water catchments for Tomsk city supply. Changes in deep waters results in changes of hydrological regime and environment transformations. Water level drawdown leads to increase of aerobic layer thickness, intensification of plant remains decomposition, peat layers compacting and rises of CO2 emission from the surface. Carbon dioxide emission from bogs of "Ob'-Tom'" key area is about two times higher than emission from pristine bogs ("Bakchar" key area). Aboveground net primary productivity determined without tree layer at all studied peatlands has similar values. Belowground net primary productivity at "Ob'-Tom'" key area if 4-7 times higher than at "Bakchar" key area depending on the ecosystem type. An essential increase in root density after water level depletion results in increase on total net productivity by 2.4 times. Carbon budget for pristine peatlands ("Bakchar" key area) varies from 27 (open fen) to 46 (low ryam) gC/m2/yr. Peatlands of "Ob'-Tom'" key area accumulates about 210 gC/m2/yr in average. Our observations of the elements of carbon exchange have shown that at present all studied peatlands act as carbon sinks. Long-term water table lowering at least at first stage stipulates carbon removing from the atmosphere and accumulation in a form of peat. Work was partially supported by Russian Fund of Basic Researches (08-05-00426/a, 08-05-92501).

Classification, description, and dynamics of plant communities after fire in the taiga of interior Alaska.

Treesearch

M. Joan Foote

1983-01-01

One hundred thirty forest stands ranging in age from I month postfire to 200 years were sampled and described by successional series (white spruce and black spruce) and by developmental stage (newly burned, moss-herb, tall shrub-sapling, dense tree, hardwood, and spruce). Patterns of change in the two successional series are described. In addition, 12 mature forest...

The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum

PubMed Central

Alexandrov, G. A.; Brovkin, V. A.; Kleinen, T.

2016-01-01

Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100. PMID:27095029

The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum.

PubMed

Alexandrov, G A; Brovkin, V A; Kleinen, T

2016-04-20

Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100.

Distribution of millipedes along an altitudinal gradient in the south of Lake Teletskoye, Altai Mts, Russia (Diplopoda)

PubMed Central

Nefedieva, Julia S.; Nefediev, Pavel S.; Sakhnevich, Miroslava B.; Dyachkov, Yuri V.

2015-01-01

Abstract The distribution of millipedes along an altitudinal gradient in the south of Lake Teletskoye, Altai, Russia based on new samples from the Kyga Profile sites, as well as on partly published and freshly revised material (Mikhaljova et al. 2007, 2008, 2014, Nefedieva and Nefediev 2008, Nefediev and Nefedieva 2013, Nefedieva et al. 2014), is established. The millipede diversity is estimated to be at least 15 species and subspecies from 10 genera, 6 families and three orders. The bulk of species diversity is confined both to low- and mid-mountain chern taiga forests and high-mountain shrub tundras, whereas the highest numbers, reaching up to 130 ind./m², is shown in subalpine Pinus sibirica sparse growths. Based on clustering studied localities on species diversity similarity two groups of sites are defined: low-mountain sites and subalpine sparse growths of Pinus sibirica ones. PMID:26257540

Sedimentation, zoning of reservoir rocks in W. Siberian basin oil fields

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

Kliger, J.A.

1994-02-07

A line pattern of well cluster spacing was chosen in western Siberia because of taiga, marshes, etc., on the surface. The zoning of the oil pools within productive Upper Jurassic J[sub 3] intervals is complicated. This is why until the early 1990s almost each third well drilled in the Shaimsky region on the western edge of the West Siberian basin came up dry. The results of development drilling would be much better if one used some sedimentological relationships of zoning of the reservoir rocks within the oil fields. These natural phenomena are: Paleobasin bathymetry; Distances from the sources of themore » clastic material; and Proximity of the area of deposition. Using the diagram in this article, one can avoid drilling toward areas where the sandstone pinch out, area of argillization of sand-stones, or where the probability of their absence is high.« less

The first finding of Asian black bear (Carnivora, Ursidae, Ursus (Euarctos) thibetanus G. Cuvier, 1823) in the Late Pleistocene of northern Eurasia.

PubMed

Kosintsev, P A; Tiunov, M P; Gimranov, D O; Panov, V S

2016-11-01

An M1 tooth of Asian black bear (Ursus (Euarctos) thibetanus G. Cuvier, 1823) was found in deposits of the Tetyukhinskaya cave (Middle Sikhote-Alin, 44°35'N, 135°36'E). This finding is the first reliable evidence of Asian black bear's presence in Pleistocene of Primorye. Its morphological and morphometric descriptions are given. The period of inhabitation of U. (E.) thibetanus determined based on the radiocarbon date obtained during the study of the tooth, is 39 874 ± 133 BP (NSK-850, UGAMS-21786), which corresponds to the middle of Marine Isotope Stage 3 (MIS 3) of Late Pleistocene. The composition of ancient theriofauna indicates the existence of wide variety of landscapes in Primorye in the middle of Late Pleistocene. A refugium of forest fauna, in which species of taiga, nemoral, and Central Asian mountain-forest theriocomplexes were present, was located in southern Primorye in Late Pleistocene.

Study of Wetland Ecosystem Vegetation Using Satellite Data

NASA Astrophysics Data System (ADS)

Dyukarev, E. A.; Alekseeva, M. N.; Golovatskaya, E. A.

2017-12-01

The normalized difference vegetation index (NDVI) is used to estimate the aboveground net production (ANP) of wetland ecosystems for the key area at the South Taiga zone of West Siberia. The vegetation index and aboveground production are related by linear dependence and are specific for each wetland ecosystem. The NDVI grows with an increase in the ANP at wooded oligotrophic ecosystems. Open oligotrophic bogs and eutrophic wetlands are characterized by an opposite relation. Maps of aboveground production for wetland ecosystems are constructed for each study year and for the whole period of studies. The average aboveground production for all wetland ecosystems of the key area, which was estimated with consideration for the area they occupy and using the data of satellite measurements of the vegetation index, is 305 g C/m2/yr. The total annual carbon accumulation in aboveground wetland vegetation in the key area is 794600 t.

Soils of Mountainous Forests and Their Transformation under the Impact of Fires in Baikal Region

NASA Astrophysics Data System (ADS)

Krasnoshchekov, Yu. N.

2018-04-01

Data on postpyrogenic dynamics of soils under mountainous taiga cedar ( Pinus sibirica) and pine ( Pinus sylvestris) forests and subtaiga-forest-steppe pine ( Pinus sylvestris) forests in the Baikal region are analyzed. Ground litter-humus fires predominating in this region transform the upper diagnostic organic soil horizons and lead to the formation of new pyrogenic organic horizons (Opir). Adverse effects of ground fires on the stock, fractional composition, and water-physical properties of forest litters are shown. Some quantitative parameters of the liquid and solid surface runoff in burnt areas related to the slope gradient, fire intensity, and the time passed after the fire are presented. Pyrogenic destruction of forest ecosystems inevitably induces the degradation of mountainous soils, whose restoration after fires takes tens of years. The products of soil erosion from the burnt out areas complicate the current situation with the pollution of coastal waters of Lake Baikal.

A Pliocene flora and insect fauna from the Bering Strait region

USGS Publications Warehouse

Hopkins, D.M.; Matthews, J.V.; Wolfe, J.A.; Silberman, M.L.

1971-01-01

A flood-plain forest has been preserved beneath a lava flow that invaded the Inmachuk River Valley in the northern part of the Seward Peninsula, Alaska, during the Pliocene Epoch. The fossil flora is of great biogeographic interest because of its position (Fig. 1) in a tundra region about 250 km east of Bering Strait, 75 km south of the Arctic Circle, and 65 km west of the northwestern limit of spruce-birch forest. It provides insight into the history of the development of the circumpolar boreal forest (taiga). A rich arthropod fauna casts light on the phylogeny of several modern insect genera and on the origin of modern tundra faunas. A potassium-argon analysis of the overlying basaltic lava provides our first radiometric age estimate (5.7??0.2 million years) for the Clamgulchian Stage, a Late Tertiary time-stratigraphic unit based on fossil plants and widely recognized in Alaska (Wolfe and Hopkins 1967) and northeastern Siberia. ?? 1971.

Development of a long-term ecological monitoring program in Denali National Park and Preserve, Alaska (USA)

USGS Publications Warehouse

Oakley, Karen L.; Debevec, Edward M.; Rexstad, Eric A.; Aguirre-Bravo, Celedonio; Franco, Carlos Rodriguez

1999-01-01

A Long-term Ecological Monitoring (LTEM) program began at Denali National Park and Preserve, Alaska (USA) in 1992, as a prototype for subarctic parks. The early history of the Denali LTEM program provides insight into the challenges that can arise during monitoring program development. The Denali program has thus far taken a watershed approach, involving collocation of study effort for a mix of abiotic and biotic attributes within a small, headwater stream (Rock Creek) which crosses the tundra-taiga boundary. An initial effort at integration and synthesis of meteorological, vegetation, small mammal and passerine bird data for the first 7 years of the program found few correlations, but power was low. We will now attempt to balance the intensive work in Rock Creek by developing a cost-effective sampling design that includes more of the park. We are also working to improve linkages between the monitoring program and park management decision-making and to strengthen data management and reporting mechanisms.

Primary gamma ray selection in a hybrid timing/imaging Cherenkov array

NASA Astrophysics Data System (ADS)

Postnikov, E. B.; Grinyuk, A. A.; Kuzmichev, L. A.; Sveshnikova, L. G.

2017-06-01

This work is a methodical study on hybrid reconstruction techniques for hybrid imaging/timing Cherenkov observations. This type of hybrid array is to be realized at the gamma-observatory TAIGA intended for very high energy gamma-ray astronomy (> 30 TeV). It aims at combining the cost-effective timing-array technique with imaging telescopes. Hybrid operation of both of these techniques can lead to a relatively cheap way of development of a large area array. The joint approach of gamma event selection was investigated on both types of simulated data: the image parameters from the telescopes, and the shower parameters reconstructed from the timing array. The optimal set of imaging parameters and shower parameters to be combined is revealed. The cosmic ray background suppression factor depending on distance and energy is calculated. The optimal selection technique leads to cosmic ray background suppression of about 2 orders of magnitude on distances up to 450 m for energies greater than 50 TeV.

Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

NASA Astrophysics Data System (ADS)

Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

2015-06-01

The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

[A field study of tundra plant litter decomposition rate via mass loss and carbon dioxide emission: the role of biotic and abiotic controls, biotope, season of year, and spatial-temporal scale].

PubMed

Pochikalov, A V; Karelin, D V

2014-01-01

Although many recently published original papers and reviews deal with plant matter decomposition rates and their controls, we are still very short in understanding of these processes in boreal and high latiude plant communities, especially in permafrost areas of our planet. First and foremost, this is holds true for winter period. Here, we present the results of 2-year field observations in south taiga and south shrub tundra ecosystems in European Russia. We pioneered in simultaneous application of two independent methods: classic mass loss estimation by litter-bag technique, and direct measurement of CO2 emission (respiration) of the same litter bags with different types of dead plant matter. Such an approach let us to reconstruct intra-seasonal dynamics of decomposition rates of the main tundra litter fractions with high temporal resolution, to estimate the partial role of different seasons and defragmentation in the process of plant matter decomposition, and to determine its factors under different temporal scale.

Rheological Properties of Automorphic and Semihydromorphic Cryometamorphic Northern Taiga Soils in Northeastern European Russia (Komi Republic)

NASA Astrophysics Data System (ADS)

Kholopov, Yu. V.; Khaidapova, D. D.; Lapteva, E. M.

2018-04-01

Soil pastes at the water content corresponding to the maximum swelling of samples from different genetic horizons of cryometamorphic soils―surface-gleyic iron-illuvial svetlozem (Folic Albic Stagnosol) and peaty and peat humus-impregnated gleyic svetlozems (Histic Gleyic Stagnosols)―have been studied with an MCR-302 modular rheometer (Anton Paar, Austria). It has been found that the strongest interparticle bonds are formed in the horizons of cryometamorphic soils characterized by high contents of humic substances and organomineral Al-Fe-humus compounds. These are horizons of podzol microprofile (Eg and BHF) in iron-illuvial svetlozem and a humus-impregnated horizon (ELhi,g) in peaty and peat svetlozems. Organomineral Al-Fe-humus compounds, as well as the seasonal freezing of soils, determine the elastic-brittle character of interparticle interactions. The contents of clay fractions, exchangeable bases, and organic and organomineral substances impart viscoelastic properties to these contacts. An enhancement of elastic-brittle properties of soil is observed under the impact of gleying and freezing. The threefold decrease of the structural interaction parameter (∫ Z) when going from automorphic to semihydromorphic conditions indicates a decrease in the resistance of peaty and peat svetlozems to mechanical loads under increasing hydromorphism compared to iron-illuvial svetlozems.

Microbial communities and transformation of carbon compounds in bog soils of the taiga zone (Tomsk oblast)

NASA Astrophysics Data System (ADS)

Grodnitskaya, I. D.; Trusova, M. Yu.

2009-09-01

Two types of bogs were studied in Tomsk oblast—Maloe Zhukovskoe (an eutrophic peat low-moor bog) and Ozernoe (an oligotrophic peat high-moor bog). The gram-negative forms of Proteobacteria were found to be dominant and amounted to more than 40% of the total population of the microorganisms investigated. In the peat bogs, the population and diversity of the hydrolytic microbial complex, especially of the number of micromycetes, were lower than those in the mineral soils. The changes in the quantitative indices of the total microbiological activity of the bogs were established. The microbial biomass and the intensity of its respiration differed and were also related to the depth of the sampling. In the Zhukovskoe peat low-moor bog, the maximal biomass of heterotrophic microorganisms (154 μg of C/g of peat) was found in the aerobic zone at a depth of 0 to 10 cm. In the Ozernoe bog, the maximal biomass was determined in the zone of anaerobiosis at a depth of 300 cm (1947 μ g of C/g of peat). The molecular-genetic method was used for the determination of the spectrum of the methanogens. Seven unidentified dominant forms were revealed. The species diversity of the methanogens was higher in the oligotrophic high-moor bog than in the eutrophic low-moor bog.

Sources of particulate organic matter discharged by the Lena River using lignin phenols

NASA Astrophysics Data System (ADS)

Winterfeld, M.; Trojahn, S.; Hefter, J.; Pittauer, D.; Zubrzycki, S.; Han, P.; Rethemeyer, J.; Mollenhauer, G.

2016-12-01

Particulate organic matter (POM) discharged by rivers and deposited offshore their mouths is generally assumed to record an integrated signal from the watershed and therefore provides an archive of past environmental changes. Yet, in large river systems the riverine POM might be trapped in flood plains and the lower reaches resulting in an inefficient transport of POM particularly from the distal parts of the watershed. Further, the POM likely undergoes degradation during transport from source to sink. The Lena River is one of these large river systems stretching from 53°N to 71°N in central Siberia. The watershed can be broadly divided into two different biomes, taiga in the south and tundra in the northernmost part. The relative contribution of these biomes to the POM load of the river and its discharge to the ocean as well as the changes it is undergoing during transport are not well understood. Here we present the lignin phenol composition of different grain size fractions (bulk, 2mm-63µm, <63µm) of soil samples taken along a latitudinal transect (63°N to 72°N) as well as in marine surface sediments and two short sediment cores covering the last 120 years offshore the main Lena discharge channels. The lignin phenol composition of the soil samples (bulk, 2mm-63µm, <63µm) reflects the change in vegetation from south to north with increasing contribution of tundra vegetation. The degree of degradation between the soil sample locations as well as grain size fractions was very heterogeneous and did not show a clear trend. However, the POM seems to be slightly more degraded in the tundra, which is unexpected as the summer period when degradation in the upper thawed part of the soil can take place is shorter in the tundra compared to the southern taiga region. The marine surface sediments were dominated by gymnosperm-derived POM, particularly close to the river mouth and in the <63µm fraction. Because of the large heterogeneity of organic matter degradation

Key Edaphic Properties Largely Explain Temporal and Geographic Variation in Soil Microbial Communities across Four Biomes.

PubMed

Docherty, Kathryn M; Borton, Hannah M; Espinosa, Noelle; Gebhardt, Martha; Gil-Loaiza, Juliana; Gutknecht, Jessica L M; Maes, Patrick W; Mott, Brendon M; Parnell, John Jacob; Purdy, Gayle; Rodrigues, Pedro A P; Stanish, Lee F; Walser, Olivia N; Gallery, Rachel E

2015-01-01

Soil microbial communities play a critical role in nutrient transformation and storage in all ecosystems. Quantifying the seasonal and long-term temporal extent of genetic and functional variation of soil microorganisms in response to biotic and abiotic changes within and across ecosystems will inform our understanding of the effect of climate change on these processes. We examined spatial and seasonal variation in microbial communities based on 16S rRNA gene sequencing and phospholipid fatty acid (PLFA) composition across four biomes: a tropical broadleaf forest (Hawaii), taiga (Alaska), semiarid grassland-shrubland (Utah), and a subtropical coniferous forest (Florida). In this study, we used a team-based instructional approach leveraging the iPlant Collaborative to examine publicly available National Ecological Observatory Network (NEON) 16S gene and PLFA measurements that quantify microbial diversity, composition, and growth. Both profiling techniques revealed that microbial communities grouped strongly by ecosystem and were predominately influenced by three edaphic factors: pH, soil water content, and cation exchange capacity. Temporal variability of microbial communities differed by profiling technique; 16S-based community measurements showed significant temporal variability only in the subtropical coniferous forest communities, specifically through changes within subgroups of Acidobacteria. Conversely, PLFA-based community measurements showed seasonal shifts in taiga and tropical broadleaf forest systems. These differences may be due to the premise that 16S-based measurements are predominantly influenced by large shifts in the abiotic soil environment, while PLFA-based analyses reflect the metabolically active fraction of the microbial community, which is more sensitive to local disturbances and biotic interactions. To address the technical issue of the response of soil microbial communities to sample storage temperature, we compared 16S-based community

The Uncertainty of Biomass Estimates from Modeled ICESat-2 Returns Across a Boreal Forest Gradient

NASA Technical Reports Server (NTRS)

Montesano, P. M.; Rosette, J.; Sun, G.; North, P.; Nelson, R. F.; Dubayah, R. O.; Ranson, K. J.; Kharuk, V.

2014-01-01

The Forest Light (FLIGHT) radiative transfer model was used to examine the uncertainty of vegetation structure measurements from NASA's planned ICESat-2 photon counting light detection and ranging (LiDAR) instrument across a synthetic Larix forest gradient in the taiga-tundra ecotone. The simulations demonstrate how measurements from the planned spaceborne mission, which differ from those of previous LiDAR systems, may perform across a boreal forest to non-forest structure gradient in globally important ecological region of northern Siberia. We used a modified version of FLIGHT to simulate the acquisition parameters of ICESat-2. Modeled returns were analyzed from collections of sequential footprints along LiDAR tracks (link-scales) of lengths ranging from 20 m-90 m. These link-scales traversed synthetic forest stands that were initialized with parameters drawn from field surveys in Siberian Larix forests. LiDAR returns from vegetation were compiled for 100 simulated LiDAR collections for each 10 Mg · ha(exp -1) interval in the 0-100 Mg · ha(exp -1) above-ground biomass density (AGB) forest gradient. Canopy height metrics were computed and AGB was inferred from empirical models. The root mean square error (RMSE) and RMSE uncertainty associated with the distribution of inferred AGB within each AGB interval across the gradient was examined. Simulation results of the bright daylight and low vegetation reflectivity conditions for collecting photon counting LiDAR with no topographic relief show that 1-2 photons are returned for 79%-88% of LiDAR shots. Signal photons account for approximately 67% of all LiDAR returns, while approximately 50% of shots result in 1 signal photon returned. The proportion of these signal photon returns do not differ significantly (p greater than 0.05) for AGB intervals greater than 20 Mg · ha(exp -1). The 50m link-scale approximates the finest horizontal resolution (length) at which photon counting LiDAR collection provides strong model

Key Edaphic Properties Largely Explain Temporal and Geographic Variation in Soil Microbial Communities across Four Biomes

PubMed Central

Borton, Hannah M.; Espinosa, Noelle; Gebhardt, Martha; Gil-Loaiza, Juliana; Gutknecht, Jessica L. M.; Maes, Patrick W.; Mott, Brendon M.; Parnell, John Jacob; Purdy, Gayle; Rodrigues, Pedro A. P.; Stanish, Lee F.; Walser, Olivia N.

2015-01-01

Soil microbial communities play a critical role in nutrient transformation and storage in all ecosystems. Quantifying the seasonal and long-term temporal extent of genetic and functional variation of soil microorganisms in response to biotic and abiotic changes within and across ecosystems will inform our understanding of the effect of climate change on these processes. We examined spatial and seasonal variation in microbial communities based on 16S rRNA gene sequencing and phospholipid fatty acid (PLFA) composition across four biomes: a tropical broadleaf forest (Hawaii), taiga (Alaska), semiarid grassland-shrubland (Utah), and a subtropical coniferous forest (Florida). In this study, we used a team-based instructional approach leveraging the iPlant Collaborative to examine publicly available National Ecological Observatory Network (NEON) 16S gene and PLFA measurements that quantify microbial diversity, composition, and growth. Both profiling techniques revealed that microbial communities grouped strongly by ecosystem and were predominately influenced by three edaphic factors: pH, soil water content, and cation exchange capacity. Temporal variability of microbial communities differed by profiling technique; 16S-based community measurements showed significant temporal variability only in the subtropical coniferous forest communities, specifically through changes within subgroups of Acidobacteria. Conversely, PLFA-based community measurements showed seasonal shifts in taiga and tropical broadleaf forest systems. These differences may be due to the premise that 16S-based measurements are predominantly influenced by large shifts in the abiotic soil environment, while PLFA-based analyses reflect the metabolically active fraction of the microbial community, which is more sensitive to local disturbances and biotic interactions. To address the technical issue of the response of soil microbial communities to sample storage temperature, we compared 16S-based community

Initial assessment of multi-scale measures of C02 and H20 flux in the Siberian taiga

Treesearch

D.Y. Hollinger; F.M. Kelliher; E.-D. Schulze; N.N. Vygodskaya; A. Varlagin; I. Milukova; J.N. Byers; A. Sogachov; J.E. Hunt; T.M. McSeveny; K.I. Kobak; G. Bauer; A. Arneth

1995-01-01

We measured CO2 and H2O fluxes between undisturbed Larix gmelinii forest and the atmosphere at a remote Eastern Siberian site in July 1993. Scaled-up leaf-level porometer measurements agreed with those derived from the eddy correlation technique for the canopy fluxes of CO2 and H...

Mapping of taiga forest units using AIRSAR data and/or optical data, and retrieval of forest parameters

NASA Technical Reports Server (NTRS)

Rignot, Eric; Williams, Cynthia; Way, Jobea; Viereck, Leslie

1993-01-01

A maximum a posteriori Bayesian classifier for multifrequency polarimetric SAR data is used to perform a supervised classification of forest types in the floodplains of Alaska. The image classes include white spruce, balsam poplar, black spruce, alder, non-forests, and open water. The authors investigate the effect on classification accuracy of changing environmental conditions, and of frequency and polarization of the signal. The highest classification accuracy (86 percent correctly classified forest pixels, and 91 percent overall) is obtained combining L- and C-band frequencies fully polarimetric on a date where the forest is just recovering from flooding. The forest map compares favorably with a vegetation map assembled from digitized aerial photos which took five years for completion, and address the state of the forest in 1978, ignoring subsequent fires, changes in the course of the river, clear-cutting of trees, and tree growth. HV-polarization is the most useful polarization at L- and C-band for classification. C-band VV (ERS-1 mode) and L-band HH (J-ERS-1 mode) alone or combined yield unsatisfactory classification accuracies. Additional data acquired in the winter season during thawed and frozen days yield classification accuracies respectively 20 percent and 30 percent lower due to a greater confusion between conifers and deciduous trees. Data acquired at the peak of flooding in May 1991 also yield classification accuracies 10 percent lower because of dominant trunk-ground interactions which mask out finer differences in radar backscatter between tree species. Combination of several of these dates does not improve classification accuracy. For comparison, panchromatic optical data acquired by SPOT in the summer season of 1991 are used to classify the same area. The classification accuracy (78 percent for the forest types and 90 percent if open water is included) is lower than that obtained with AIRSAR although conifers and deciduous trees are better separated due to the presence of leaves on the deciduous trees. Optical data do not separate black spruce and white spruce as well as SAR data, cannot separate alder from balsam poplar, and are of course limited by the frequent cloud cover in the polar regions. Yet, combining SPOT and AIRSAR offers better chances to identify vegetation types independent of ground truth information using a combination of NDVI indexes from SPOT, biomass numbers from AIRSAR, and a segmentation map from either one.

Climate change impact on peatland and forest ecosystems of Russia

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

Kondrasheva, N.Yu.; Kobak, K.I.; Turchinovich, I.Ye.

1996-12-31

Paleoclimatic and paleobotanic reconstructions allow a conclusion that ecosystems and natural zones significantly changed due to climate fluctuations. The average long-term carbon accumulation in peatlands of Russia was estimated as 45.6 mln tons of carbon per year. During the Holocene the rate of peat accumulation changed. During the Subboreal period the rate of peat accumulation gradually decreased to 17 gC/m2 yr, reaching its lowest value in the Subatlantic period. Apparently, the rate of peat accumulation decreased in Subboreal period due to sharp cooling and precipitation decrease. Future rates of peat accumulation might be higher than the present one. Forest ecosystemsmore » of north-western Russia also significantly changed during the Holocene. In Atlantic time the boundary between middle and south taiga was located 500 km northward compared to the present and broad-leaved forest occupied large areas. According to their forecast, a mean global air temperature increase by 1.4 C is expected to result in a considerable decrease in coniferous forest area and an increase in mixed and broad-leaved forest area.« less

Acidification of forest soil in Russia: From 1893 to present

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

Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.

2003-01-02

It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations similar to 100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases inmore » precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place.« less

Towards a cosmic-ray mass-composition study at Tunka Radio Extension

NASA Astrophysics Data System (ADS)

Kostunin, D.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Schröder, F. G.; Wischnewski, R.; Zagorodnikov, A.

2017-03-01

The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA facility located in Siberia nearby the southern tip of Lake Baikal. Tunka-Rex measures air-showers induced by high-energy cosmic rays, in particular, the lateral distribution of the radio pulses. The depth of the air-shower maximum, statistically depends on the mass of the primary particle, is determined from the slope of the lateral distribution function (LDF). Using a model-independent approach, we have studied possible features of the one-dimensional slope method and tried to find improvements for the reconstruction of primary mass. To study the systematic uncertainties given by different primary particles, we have performed simulations using the CONEX and CoREAS software packages of the recently released CORSIKA v7.5 including the modern high-energy hadronic models QGSJet-II.04 and EPOS-LHC. The simulations have shown that the largest systematic uncertainty in the energy deposit is due to the unknown primary particle. Finally, we studied the relation between the polarization and the asymmetry of the LDF.

Late quaternary environments, Denali National Park and Preserve, Alaska

USGS Publications Warehouse

Elias, S.A.; Short, S.K.; Waythomas, C.F.

1996-01-01

Late Quaternary pollen, plant macrofossils, and insect fossils were studied from sites along three rivers in the foothills north of the Alaska Range in Denali National Park and Preserve. The aim was to carry out a reconaissance of late Quaternary organic sediments in the region, emphasizing the mid-Wisconsin, or Boutellier interstadial interval. Samples of probable early- to mid-Boutellier age (ca. 60 000 to 40 000 B.P.) from Unit 2 at the Toklat High Bluffs site indicate open boreal woodland with dense alder shrub vegetation. Organic Unit 1 at the Foraker River Slump site indicates open taiga with shrubs of probable Boutellier age. Fossil evidence from the youngest horizon in this unit indicates graminoid tundra environments, marking the transition from interstadial to late Wisconsin glacial environments. Early Holocene samples from the Foraker exposures suggest birch shrub tundra; coniferous forest apparently became established only alter 6500 B.P. Local variations in forest composition at the Foraker and Sushana sites were probably the result of disturbances, such as fire.

Acidification of forest soil in Russia: From 1893 to present

USGS Publications Warehouse

Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.; Bobrov, A.A.; Torn, M.S.; Harden, J.W.

2004-01-01

It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations ???100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases in precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place. Copyright 2004 by the American Geophysical Union.

Effect of aluminum, zinc, copper, and lead on the acid-base properties of water extracts from soils

NASA Astrophysics Data System (ADS)

Motuzova, G. V.; Makarychev, I. P.; Petrov, M. I.

2013-01-01

The potentiometric titration of water extracts from the upper horizons of taiga-zone soils by salt solutions of heavy metals (Pb, Cu, and Zn) showed that their addition is an additional source of the extract acidity because of the involvement of the metal ions in complexation with water-soluble organic substances (WSOSs). At the addition of 0.01 M water solutions of Al(NO3)3 to water extracts from soils, Al3+ ions are also involved in complexes with WSOSs, which is accompanied by stronger acidification of the extracts from the upper horizon of soddy soils (with a near-neutral reaction) than from the litter of bog-podzolic soil (with a strongly acid reaction). The effect of the Al3+ hydrolysis on the acidity of the extracts is insignificantly low in both cases. A quantitative relationship was revealed between the release of protons and the ratio of free Cu2+ ions to those complexed with WSOSs at the titration of water extracts from soils by a solution of copper salt.

Individual organic compounds in water extracts from podzolic soils of the Komi Republic

NASA Astrophysics Data System (ADS)

Shamrikova, E. V.; Punegov, V. V.; Gruzdev, I. V.; Vanchikova, E. V.; Vetoshkina, A. A.

2012-10-01

The contents of organic compounds in water extracts from organic horizons of loamy soils with different water contents from the medium taiga zone of the Komi Republic were determined by gas-liquid chromatography and chromatography-mass spectrometry. The mass concentration of organic carbon in the extracts was in the range of 290-330 mg/dm3; the mass fraction of the carbon from the identified compounds was 0.5-1.9%. Hydrocarbons made up about 60% of the total identified compounds; acids and their derivatives composed less than 40%. Most of the acids (40-70%) were aliphatic hydroxy acids. The tendencies in the formation of different classes of organic compounds were revealed depending on the degree of the soil hydromorphism. The acid properties of the water-soluble compounds were studied by pK spectroscopy. Five groups of compounds containing acid groups with similar pKa values were revealed. The compounds containing groups with pKa < 4.0 were predominant. The increase in the surface wetting favored the formation of compounds with pKa 3.2-4.0 and 7.4-8.4.

Extremophilic and extremotolerant actinomycetes in different soil types

NASA Astrophysics Data System (ADS)

Zenova, G. M.; Manucharova, N. A.; Zvyagintsev, D. G.

2011-04-01

Problems on the resistance of soil actinomycetes to various environmental factors (pH, salinity, temperature, and moisture) are discussed. Actinomycetes as a special group of prokaryotes were revealed to have a greater range of tolerance to these factors than was thought earlier. The regularities of the distribution of extremophilic and extremotolerant actinomycetes developing in unusual for mycelial bacteria conditions, their structural-functional characteristics, and their taxonomic composition were determined. The predominance of acidophilic representatives of the Micromonospora genus in acid soils (typical peat, soddy-podzolic, and taiga podzol) and the haloalkaliphilic Streptomyces pluricilirescens and S. prunicolor species in desert saline soils are shown. The specific features of the actinomycete complexes on thermal fields of the weakly developed stratified volcanic soils are described. In these complexes, the thermophilic forms were represented only by species of the Micromonospora genus; and the mesophilic forms, by Microbispora species. In the periodically heated desert soils, among the thermophilic actinomycetes, representatives of rare Actinomadura, Saccharopolyspora and Streptosporangium genera along with Streptomyces species were indicated. The mechanisms of the resistance of the actinomycetes to the extreme environmental conditions are discussed.

Decomposition rate of peat-forming plants in the oligotrophic peatland at the first stages of destruction

NASA Astrophysics Data System (ADS)

Nikonova, L. G.; Golovatskaya, E. A.; Terechshenko, N. N.

2018-03-01

The research presents quantitative estimates of the decomposition rate of plant residues at the initial stages of the decay of two plant species (Eriophorum vaginatum and Sphagnum fuscum) in a peat deposit of the oligotrophic bog in the southern taiga subzone of Western Siberia. We also studied a change in the content of total carbon and nitrogen in plant residues and the activity of microflora in the initial stages of decomposition. At the initial stage of the transformation process of peat-forming plants the losses of mass of Sph. fuscum is 2.5 times lower then E. vaginatum. The most active mass losses, as well as a decrease in the total carbon content, is observed after four months of the experiment. The most active carbon removal is characteristic for E. vaginatum. During the decomposition of plant residues, the nitrogen content decreases, and the most intense nitrogen losses were characteristic for Sph. fuscum. The microorganisms assimilating organic and mineral nitrogen are more active in August, the oligotrophic and cellulolytic microorganisms – in July.

Actinobacteria possessing antimicrobial and antioxidant activities isolated from the pollen of scots pine (Pinus sylvestris) grown on the Baikal shore.

PubMed

Axenov-Gribanov, Denis V; Voytsekhovskaya, Irina V; Rebets, Yuriy V; Tokovenko, Bogdan T; Penzina, Tatyana A; Gornostay, Tatyana G; Adelshin, Renat V; Protasov, Eugenii S; Luzhetskyy, Andriy N; Timofeyev, Maxim A

2016-10-01

Isolated ecosystems existing under specific environmental conditions have been shown to be promising sources of new strains of actinobacteria. The taiga forest of Baikal Siberia has not been well studied, and its actinobacterial population remains uncharacterized. The proximity between the huge water mass of Lake Baikal and high mountain ranges influences the structure and diversity of the plant world in Siberia. Here, we report the isolation of eighteen actinobacterial strains from male cones of Scots pine trees (Pinus sylvestris) growing on the shore of the ancient Lake Baikal in Siberia. In addition to more common representative strains of Streptomyces, several species belonging to the genera Rhodococcus, Amycolatopsis, and Micromonospora were isolated. All isolated strains exhibited antibacterial and antifungal activities. We identified several strains that inhibited the growth of the pathogen Candida albicans but did not hinder the growth of Saccharomyces cerevisiae. Several isolates were active against Gram-positive and Gram-negative bacteria. The high proportion of biologically active strains producing antibacterial and specific antifungal compounds may reflect their role in protecting pollen against phytopathogens.

Arctic ecosystem reaction on permafrost melting as a result of 40 years anthropogenic impact

NASA Astrophysics Data System (ADS)

Petrzhik, Nataliya; Matyshak, George; Myshonkov, Alexander; Petrov, Dmitry

2017-04-01

Arctic ecosystems are sensitive indicators of environmental change. The increasing of anthropogenic impact perturb the natural ecosystems balance, first of all significant changes happen in soil and vegetation. It is necessary to study the permafrost ecosystem response, as the permafrost covers the quarter of the world and more than a half of Russia. Since 1960 the oil and gas industry grows in Russia. The hydrocarbons can be transferred by pipelines only in the heated state. The main effect of construction and operation of pipeline is the heating of soil and permafrost degradation. The goal of this study was to estimate the response of landscapes and permafrost ecosystem of north of West Siberia to the cumulative action of pipelines. The main objective was to investigate the warming impact on the properties and function of the soil along the pipelines in permafrost zone. The studied object was vegetation and soil cover of the north of Western Siberia ecosystems after the action of pipelines. The areas with maximum effect of heat lines were selected by remote sensing. Ten transects of 50 meters in length with sampling points every 5 meters from pipeline to undisturbed background area were selected in three different natural zones. The soil and vegetation cover was described, sampled, active layer of soil and the power of organic horizon were measured, the hydrothermal regime of soils in a layer of 0-10 cm was measured, the emission of greenhouse gas was studied. In the laboratory, the content of labile carbon, microbial biomass carbon, basal and substrate-induced respiration were measured. The main effect of the pipelines impact is the active degradation of permafrost and changes in hydrothermal settings. From background to broken areas the following settings changing: the depth of thawing increase in 10 times; the soil temperature changes from 4 to 10,5 ° C in taiga, from 4.5 to 13,5 ° C in tundra, from 5.5 to 12 ° C in forest-tundra; the soil moisture reduces

[Estimation of the biological age in taiga tick females (Ixodes persulcatus:Ixodidae) by the fat reserves in organism].

PubMed

Balashov, Iu S; Grigor'eva, L A

2010-01-01

The method of estimation of the biological age in non-feeding tick females by the level of adipose inclusions in the cells of the midgut and fat body is developed. In order to estimate the fat reserves in non-feeding females, alive ticks were dissected and fragments of their internal were vitally stained with the pregnant solution of sudan III in 70 % ethanol. Three age-specific groups were established: I, young females whose intestines and fat body were filled with fat inclusions; II, mature females whose fat reserves were partially expended; III, old females having isolated fat inclusions in their midgut and fat body.

Impact of tree cutting on water-soluble organic compounds in podzolic soils of the European North-East

NASA Astrophysics Data System (ADS)

Lapteva, Elena; Bondarenko, Natalia; Shamrikova, Elena; Kubik, Olesya; Punegov, Vasili

2016-04-01

Water-soluble organic compounds (WOCs) and their single components, i.e. low-molecular organic acids, alcohols, and carbohydrates, attain a great deal of attention among soil scientists. WOCs are an important component of soil organic matter (SOM) and form as a results of different biological and chemical processes in soils. These processes are mainly responsible for formation and development of soils in aboveground ecosystems. The purpose of the work was identifying qualitative and quantitative composition of low-molecular organic substances which form in podzolic loamy soils against natural reforestation after spruce forest cutting. The studies were conducted on the territory of the European North-East of Russia, in the middle taiga subzone (Komi Republic, Ust-Kulom region). The study materials were soil of undisturbed bilberry spruce forest (Sample Plot 1 (SP1)) and soils of different-aged tree stands where cutting activities took place in winter 2001/2002 (SP2) and 1969/1970 (SP3). Description of soils and vegetation cover on the plots is given in [1]. Low-molecular organic compounds in soil water extracts were identified by the method of gas chromatography mass-spectrometry [2, 3]. Finally, reforestationafterspruceforestcutting was found to be accompanied by different changes in soil chemical composition. In contrast with soils under undisturbed spruce forest, organic soil horizons under different-aged cuts decreased in organic carbon reserves and production of low-molecular organic compounds, changed in soil acidity. Within the soil series of SP1→SP2→SP3, the highest content of WOCs was identified for undisturbed spruce forest (738 mg kg-1 soil). In soils of coniferous-deciduous forests on SP1 and SP3, WOC content was 294 and 441 mg kg-1 soil, correspondingly. Soils at cuts decreased in concentration of any water-soluble low-molecular SOM components as low-molecular acids, alcohols, and carbohydrates. Structure of low-molecular WOCs in the study podzolic

[Methanotrophic bacteria in cold seeps of the floodplains of northern rivers].

PubMed

Belova, S É; Oshkin, I Iu; Glagolev, M V; Lapshina, E D; Maksiutov, Sh Sh; Dedysh, S N

2013-01-01

Small mud volcanoes (cold seeps), which are common in the floodplains of northern rivers, are a potentially important, although poorly studied sources of atmospheric methane. Field research on the cold seeps of the Mukhrina River (Khanty-Mansiysk Autonomous okrug, Russia) revealed methane fluxes from these structures to be orders of magnitude higher than from equivalent areas of the mid-taiga bogs. Microbial communities developing around the seeps were formed under conditions of high methane concentrations, low temperatures (3-5 degrees C), and near-neutral pH. Molecular identification of methane-oxidizing bacteria from this community by analysis of the pmoA gene encoding particulate methane monooxygenase revealed both type I and type II methanotrophs (classes Gammaproteobacteria and Alphaproteobacteria, respectively), with predomination of type I methanotrophs. Among the latter, microorganisms related to Methylobacterpsychrophilus and Methylobacter tundripaludum, Crenothrix polyspora (a stagnant water dweller), and a number of methanotrophs belonging to unknown taxa were detected. Growth characteristics of two isolates were determined. Methylobactersp. CMS7 exhibited active growth at 4-10 degrees C, while Methylocystis sp. SB12 grew better at 20 degrees C. Experimental results confirmed the major role ofmethanotrophic gammaproteobacteria in controlling the methane emission from cold river seeps.

The temperature characteristics of biological active period of the peat soils of Bakchar swamp

NASA Astrophysics Data System (ADS)

Kiselev, M. V.; Dyukarev, E. A.; Voropay, N. N.

2018-01-01

The results of the study of the peculiarities of the temperature regime in the five basic ecosystems of oligotrophic bogs in the south taiga zone of Western Siberia in 2011-2016 are presented. The soil temperature regime was studied using the atmospheric-soil measuring complex at different depths from surface to 240 cm. All sites were divided into two groups according the bog water level: flooded sites (hollow and open fen) and drained sites (ridge, tall and low ryam). Waterlogged sites are better warmed in the summer period, and slowly freeze in the winter period. The analysis of the annual cycle of temperature showed that the maximum surface temperature is observed in July. The minimum temperature on the surface observed in February or January. The greatest temperature gradient was recorded in the upper 2 cm layer. The gradient at the open fen was -2 °C·cm-1 in February and 1.1 °C·cm-1 in October. The peak of formation of the seasonally frozen layer occurs at the end of autumn, beginning of winter. The degradation of the seasonally frozen layer was observed both from top and bottom, but degradation from the top is faster.

Functional profile of black spruce wetlands in Alaska

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

Post, R.A.

1996-09-01

The profile describes the ecologic context and wetland functions of black spruce (Picea mariana) wetlands (BSWs) covering about 14 million ha of Alaska taiga. Ecologic descriptions include climate, permafrost, landforms, post-Pleistocene vegetation, fire, successional processes, black spruce community types and adaptations, and characteristics of BSWs. The profile describes human activities potentially affecting BSWs and identifies research literature and data gaps generally applicable to BSWs. Hydrologic, water quality, global biogeochemical, and ecologic functions of BSWs, as well as their socioeconomic uses, appear in the profile, along with potential functional indicators, expected sensitivities of functions to fill placement or weltand drainage, andmore » potential mitigation strategies for impacts. Functional analysis separately considers ombrotrophic and minerotrophic BSWs where appropriate. Depending on trophic status, Alaska`s BSWs perform several low-magnitude hydrologic (groundwater discharge and recharge, flow regulation, and erosion control) and ecologic (nutrient export, nutrient cycling, and food-chain support) functions and several substantial water quality (sediment retention, nutrient transformation, nutrient uptake, and contaminant removal), global biogeochemical (carbon cycling and storage), and ecologic (avian and mammalian habitat) functions. BSWs also provide important socioeconomic uses: harvested of wetland-dependent fish, wildlife, and plant resources and active winter recreation.« less

Latest results of the Tunka Radio Extension

NASA Astrophysics Data System (ADS)

Kostunin, D.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Marshalkina, T.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Schröder, F. G.; Wischnewski, R.; Zagorodnikov, A.

2017-06-01

The Tunka Radio Extension (Tunka-Rex) is an antenna array consisting of 63 antennas at the location of the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) in Eastern Siberia, nearby Lake Baikal. Tunka-Rex is triggered by the air-Cherenkov array Tunka-133 during clear and moonless winter nights and by the scintillator array Tunka-Grande during the remaining time. Tunka-Rex measures the radio emission from the same air-showers as Tunka-133 and Tunka-Grande, but with a higher threshold of about 100 PeV. During the first stages of its operation, Tunka-Rex has proven, that sparse radio arrays can measure air-showers with an energy resolution of better than 15% and the depth of the shower maximum with a resolution of better than 40 g/cm2. To improve and interpret our measurements as well as to study systematic uncertainties due to interaction models, we perform radio simulations with CORSIKA and CoREAS. In this overview we present the setup of Tunka-Rex, discuss the achieved results and the prospects of mass-composition studies with radio arrays.

Natural variations of earth`s climates impact both biologic evolution and extinction

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

Bowen, R.L.

1996-12-31

Studies of Quaternary climatic history indicate that average annual temperatures have varied by 3-5{degrees}C in equatorial regions to more than 30{degrees}C in high latitudes as episodes of interglaciation (IG) and glacial Maxima (GM) alternated. Additionally, during GM, 15-18% of present land area was converted into an ice-covered biologic desert while taiga and rain-forest shrank to less than half their present extent. During IGs, conditions resembling the present or even more benign climates prevailed. As GM developed, biologically fecund habitats shrank greatly with an associated extinction of habitat-sensitive species in great numbers. Similarly, deglaciations reopened habitats closed by GMs. These becamemore » occupied both by territorial expansion of surviving taxa and evolutionary radiation producing new species to occupy habitats that were non-existent during GMs. Studies of island biogeography and biotic responses to industrialization and landscape alteration by recent human activities support calculations that, since the last GM (18,000 yBP), new species originated at about 2000 species per year (net, around 1350 species/yr). Such origination rates appear driven by the persistent dynamism and disequilibrium. of Earth`s biologic and physical systems.« less

Glacial Refugium of Pinus pumila (Pall.) Regel in Northeastern Siberia

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

Shilo, N A; Lozhkin, A V; Anderson, P M

One of the most glowing representatives of the Kolyma flora [1], ''Pinus pumila'' (Pall.) Regel (Japanese stone pine), is a typical shrub in larch forests of the northern Okhotsk region, basins of the Kolyma and Indigirka rivers, and high-shrub tundra of the Chukchi Peninsula. It also forms a pine belt in mountains above the forest boundary, which gives way to the grass-underbrush mountain tundra and bald mountains. In the southern Chukchi Peninsula, ''Pinus pumila'' along with ''Duschekia fruticosa'' (Rupr.) Pouzar and ''Betula middendorffii'' Trautv. et C. A. Mey form trailing forests transitional between tundra and taiga [2]. Pinus pumila pollen,more » usually predominating in subfossil spore-and-pollen spectra of northeastern Siberia, is found as single grains or a subordinate component (up 2-3%, rarely 10%) in spectra of lacustrine deposits formed during the last glacial stage (isotope stage 2) in the Preboreal and Boreal times of the Holocene. Sometimes, its content increases to 15-22% in spectra of lacustrine deposits synchronous to the last glacial stage near the northern coast of the Sea of Okhotsk [3], evidently indicating the proximity of Japanese stone pine thickets.« less

Pollen-based biomes for Beringia 18,000, 6000 and 0 14C yr BP

USGS Publications Warehouse

Edwards, M.E.; Anderson, P.M.; Brubaker, L.B.; Ager, T.A.; Andreev, A.A.; Bigelow, N.H.; Cwynar, L.C.; Eisner, Wendy R.; Harrison, S.P.; Hu, F.-S.; Jolly, D.; Lozhkin, A.V.; MacDonald, G.M.; Mock, Cary J.; Ritchie, J.C.; Sher, A.V.; Spear, R.W.; Williams, J.W.; Yu, G.

2000-01-01

The objective biomization method developed by Prentice et al. (1996) for Europe was extended using modern pollen samples from Beringia and then applied to fossil pollen data to reconstruct palaeovegetation patterns at 6000 and 18,000 14C yr BP. The predicted modern distribution of tundra, taiga and cool conifer forests in Alaska and north-western Canada generally corresponds well to actual vegetation patterns, although sites in regions characterized today by a mosaic of forest and tundra vegetation tend to be preferentially assigned to tundra. Siberian larch forests are delimited less well, probably due to the extreme under-representation of Larix in pollen spectra. The biome distribution across Beringia at 6000 14C yr BP was broadly similar to today, with little change in the northern forest limit, except for a possible northward-advance in the Mackenzie delta region. The western forest limit in Alaska was probably east of its modern position. At 18,000 14C yr BP the whole of Beringia was covered by tundra. However, the importance of the various plant functional types varied from site to site, supporting the idea that the vegetation cover was a mosaic of different tundra types.

Changes in Spring Vegetation Activity over Eurasian Boreal Forest Associated with Reduction of Arctic Sea Ice

NASA Astrophysics Data System (ADS)

Koh, Y.; Jeong, J. H.; Kim, B. M.; Park, T. W.; Jeong, S. J.

2017-12-01

Vegetation activities over the high-latitude in the Northern-Hemisphere are known to be very sensitive to climate change, which can, in turn, affect the entire climate system. This is one of the important feedback effects on global climate change. In this study, we have detected a declining trend of vegetation index in the boreal forest (Taiga) region of Eurasia in early spring from the late 1990s, and confirmed that the cause is closely related to the decrease in winter temperature linked to the Arctic sea ice change. The reduction of Arctic sea ice induces weakening of the Polar vortex around the Arctic, which has a chilling effect throughout Eurasia until the early spring (March) by strengthening the Siberian high in the Eurasian continent. The decrease of vegetation growth is caused by the extreme cold phenomenon directly affecting the growth of the boreal trees. To verify this, we used vegetation-climate coupled models to investigate climate-vegetation sensitivity to sea ice reduction. As a result, when the Arctic sea ice decreased in the model simulation, the vegetation index of the boreal forest, especially needleleaf evergreen trees, decreased as similarly detected by observations.

Analysis of vegetation dynamics and climatic variability impacts on greenness across Canada using remotely sensed data from 2000 to 2009

NASA Astrophysics Data System (ADS)

Fang, Xiuqin; Zhu, Qiuan; Chen, Huai; Ma, Zhihai; Wang, Weifeng; Song, Xinzhang; Zhao, Pengxiang; Peng, Changhui

2014-01-01

Using time series of moderate-resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data from 2000 to 2009, we assessed decadal vegetation dynamics across Canada and examined the relationship between NDVI and climatic variables (precipitation and temperature). The Palmer drought severity index and vapor pressure difference (VPD) were used to relate the vegetation changes to the climate, especially in cases of drought. Results indicated that MODIS NDVI measurements provided a dynamic picture of interannual variation in Canadian vegetation patterns. Greenness declined in 2000, 2002, and 2009 and increased in 2005, 2006, and 2008. Vegetation dynamics varied across regions during the period. Most forest land shows little change, while vegetation in the ecozone of Pacific Maritime, Prairies, and Taiga Shield shows more dynamics than in the others. Significant correlations were found between NDVI and the climatic variables. The variation of NDVI resulting from climatic variability was more highly correlated to temperature than to precipitation in most ecozones. Vegetation grows better with higher precipitation and temperature in almost all ecozones. However, vegetation grows worse under higher temperature in the Prairies ecozone. The annual changes in NDVI corresponded well with the change in VPD in most ecozones.

Seasonally frozen layer in natural and drained peatlands at the South of West Siberia, Russia

NASA Astrophysics Data System (ADS)

Dyukarev, Egor; Kiselev, Maxim; Voropay, Nadezhda; Preis, Yulia

2017-04-01

The temperature regime of soils in natural and drained peatlands at Bakchar bog located in the South Taiga zone of West Siberia is studied. Soil temperature for depths up to 320 cm was registered using autonomous temperature profile recorder during the period from August 2010 to September 2016. Maximal and minimal temperatures were registered at surface in July and February, consequently. Extreme soil temperatures at 320 cm depth shifts to December (maximum) and July (minimum) reducing absolute values. Annual peat soil temperature amplitude decrease with depth from 21,8 °C on surface to 1,1 °C at 320 cm. The analysis of daily, month and annual mean data of temperature in peat soil has shown that seasonally frozen layer was registered up to 20-60 cm depth. The duration of seasonally freeze layer existence varies from 130 to 180 days. Drained peatlands with the lowest water table have highest freeze depth. Soil at water-logged sedge-sphagnum fen in winter is warmer than soil in ryam ecosystem and mineral soil at upland. Maximal freezing depth in peatlands is up to 3 times lower than at drain areas.

Multi-Sensor Remote Sensing of Forest Dynamics in Central Siberia

NASA Technical Reports Server (NTRS)

Ransom, K. J.; Sun, G.; Kharuk, V. I.; Howl, J.

2011-01-01

The forested regions of Siberia, Russia are vast and contain about a quarter of the world's forests that have not experienced harvesting. However, many Siberian forests are facing twin pressures of rapidly changing climate and increasing timber harvest activity. Monitoring the dynamics and mapping the structural parameters of the forest is important for understanding the causes and consequences of changes observed in these areas. Because of the inaccessibility and large extent of this forest, remote sensing data can play an important role for observing forest state and change. In Central Siberia, multi-sensor remote sensing data have been used to monitor forest disturbances and to map above-ground biomass from the Sayan Mountains in the south to the taiga-tundra boundaries in the north. Radar images from the Shuttle Imaging Radar-C (SIR-C)/XSAR mission were used for forest biomass estimation in the Sayan Mountains. Radar images from the Japanese Earth Resources Satellite-1 (JERS-1), European Remote Sensing Satellite-1 (ERS-1) and Canada's RADARSAT-1, and data from ETM+ on-board Landsat-7 were used to characterize forest disturbances from logging, fire, and insect damage in Boguchany and Priangare areas.

Input and behavior of polycyclic aromatic hydrocarbons in arable, fallow, and forest soils of the taiga zone (Tver oblast)

NASA Astrophysics Data System (ADS)

Zhidkin, A. P.; Gennadiev, A. N.; Koshovskii, T. S.

2017-03-01

Contents of 11 most prevalent polycyclic aromatic hydrocarbons (PAHs) in snow and soils of arable, fallow, and forest areas significantly remote from impact technogenic sources of polyarenes have been examined in the Torzhok district of Tver oblast. From the analysis of snow samples, the volumes and composition of PAHs coming from the atmosphere onto the areas of different land use have been determined. Light hydrocarbons prevail in PAHs. They make up 65-70% of total PAHs; their share in soils reaches almost 95%. An increase in the content of PAHs is revealed in fallow soils compared to arable and afforested areas. A direct relationship is revealed between the lateral distribution of total PAHs and the content of organic carbon. The distribution of total PAHs is surface-accumulative in forest soils, mainly uniform in arable soils, and deepaccumulative in fallow soils. PAH groups characterized by similar radial distributions and ratios between their reserves in snow and soils are distinguished: (1) fluorene and phenanthrene, (2) biphenyl and naphthalene, (3) benzo(a)anthracene, chrysene, perylene, and benzo[ a]pyrene, and (4) anthracene and benzo[ ghi]pyrene.

P$sup 32$-TESTS FOR INVESTIGATING THE COMPETITION BETWEEN TREE ROOTS AND REGROWTH IN SOUTHERN TAIGA FORESTS (in Russian)

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

Karpov, V.G.

1962-09-21

Introduction of radioactive materials into soil nutrients represents an excellent tool for determining utilization of the nutrient and its ultimate distribution between the various components of the phytocaenosis; therefore P/sup 32/labeled solutions were used for clarifying the competition between the roots of mature birch, Betulla verrucosa, and fir, Picea excelsa, seedlings. The test area contained 30to 35-year-old trees at a density of about 7 to 8 thousand trees per bectare. During the summer of 1960 fir seedlings were planted in areas removed from the influence of the birch roots and near the trees without interfering with interaction between the 2more » systems; at the latter location the soil contained 730 to 1100 g/m/sup 2/ of roots. In July 1961 10 mg/liter P solution, labeled with P/sup 32/ was introduced into the soil; the original activity of the solution was 65 mu c/liter. Results indicated that competition by the birch roots strongly inhibits the P/sup 32/ uptake by the 2-year-old seedlings; the radioactivity of the fir needles planted in isolated areas was 5 to 8 times higher than that in seedlings planted near the mature trees. (TTT)« less

Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with 137Cs, 226Ra, and 238U

NASA Astrophysics Data System (ADS)

Chevychelov, A. P.; Sobakin, P. I.

2017-12-01

The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El'kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.

Assessment of Soil Water Composition in the Northern Taiga Coniferous Forests of Background Territories in the Industrially Developed Region

NASA Astrophysics Data System (ADS)

Lukina, N. V.; Ershov, V. V.; Gorbacheva, T. T.; Orlova, M. A.; Isaeva, L. G.; Teben'kova, D. N.

2018-03-01

The composition of soil water under coniferous forests of Murmansk oblast—an industrially developed region of northern Russia—was investigated. The studied objects were dwarf-shrub-green-moss spruce forests and dwarf-shrub-lichen pine forests on Al-Fe-humus podzols ( Albic Rustic Podzols) that are widespread in the boreal zone. The concentrations and removal of organic carbon performing the most important biogeochemical and pedogenic functions were estimated. The results proved significant intra- and inter-biogeocenotic variability in the composition of atmospheric depositions and soil water. Carbon removal with soil water from organic and mineral horizons within elementary biogeoareas (EBGA) under tree crowns was 2-5 and 2-3 times (in some cases, up to 10 times) greater than that in the intercrown areas, respectively. The lowest critical level of mineral nitrogen (0.2 mg/L) was, as a rule, exceeded in tree EBGAs contrary to intercrown areas. Concentrations of sulfates and heavy metals in water of tree EBGA were 3-5 times greater than those in inter-crown areas. Significant inter-biogeocenotic variations related to differences in the height of trees and tree stand density were found. It is argued that adequate characterization of biochemical cycles and assessment of critical levels of components in soil water of forest ecosystems should be performed with due account for the intra- and inter-biogeocenotic variability.

Specific features of the morphology and chemical properties of coarse-textured postagrogenic soils of the southern taiga, Kostroma oblast

NASA Astrophysics Data System (ADS)

Telesnina, V. M.; Vaganov, I. E.; Karlsen, A. A.; Ivanova, A. E.; Zhukov, M. A.; Lebedev, S. M.

2016-01-01

The properties of loamy sandy postagrogenic soils in the course of their natural overgrowing were studied in the southeastern part of Kostroma oblast. Micromorphological indications of tillage were preserved in these soils at least 35-40 years after the cessation of their agricultural use. In the course of the soil overgrowing with forest vegetation, the bulk density of the upper part of the former plow horizon decreased, the pH and the ash content of the litter horizon somewhat lowered with a simultaneous increase in the acidity of the upper mineral horizon, especially at the beginning of the formation of the tree stand. In 5-7 years after the cessation of tillage, the former plow horizon was differentiated with respect to the organic carbon content. The total pool of organic carbon in the upper 30 cm increased. In the course of the further development, in the postagrogenic soil under the 90to 100-year-old forest, the organic carbon pool in this layer became lower. The soil of the young fallow (5-7 years) was characterized by the higher values of the microbial biomass in the upper mineral horizon in comparison with that in the plowed soil. In general, the microbial biomass in the studied postagrogenic ecosystems (the soils of the fields abandoned in 2005 and 2000 and the soil under the secondary 40-year-old forest) was lower than that in the soil of the subclimax 90to 100-year-old forest. The enzymatic activity of the soils tends to increase during the succession. The restoration of the invertase and, partly, catalase activities to the values typical of the soils under mature forests takes place in about 40 years.

Metal ion complex formation in small lakes of the Western Siberian Arctic zone

NASA Astrophysics Data System (ADS)

Kremleva, Tatiana; Dinu, Marina

2017-04-01

The paper is based on joint investigation of the Tyumen State University (Russia, Tyumen) and the Geochemistry and Analytical Chemistry Vernadsky Institute of Russian Academy of Sciences (Moscow, Russia) during 2012-2014 period. It presents the results of research of chemical composition of about 70 small lakes located in the area of tundra and northern taiga of West Siberia (Russia, Yamal-Nenets and Khanty-Mansi Autonomous Districts of the Tyumen region). The investigation includes determination of different parameters of natural water samples: • content of trace elements (Al, Fe, Mn, Cr, Cu, Ni, Zn, Cd, Co, Pb, etc., total more than 60 elements) by emission method with an inductively coupled plasma (ICP-MS) using mass spektrometrometre Element 2 equipment; • content of inorganic and total carbon (TIC and TC) by elemental analysis and the difference between the total and inorganic carbon gives the organic carbon content (TOC); • pH value by potentiometric method; • content of basic ions (Na+, Ca2+, K+, Mg2+, NH4+, Cl-, SO42-, NO3-, PO43-) by ion chromatography. Determination of the chemical composition of samples was conducted in the accredited laboratory according to standard procedures with regular quality control of results. Heavy metals in natural waters can exist in various forms: free (hydrated) ions bound in complexes with organic or inorganic ligands, as well as in the form of suspensions. The form of metal existence has a significant influence on their availability to transport in aquatic organisms. Metal ions associated in stable complexes with organic substances are considered less toxic. From the previous investigations state that the most stable complexes are ligands with organic ions Fe3+, Al3+. The main conclusion of the present research states that if the total content of aluminum, iron and manganese ions (meq/dm3) is equal to or greater than the concentration of dissolved organic carbon (TOC, mg/dm3) in lakes water other heavy metals will

Possible climate warming effects on vegetation, forests, biotic (insect, pathogene) disturbances and agriculture in Central Siberia for 1960- 2050

NASA Astrophysics Data System (ADS)

Tchebakova, N. M.; Parfenova, E. I.; Soja, A. J.; Lysanova, G. I.; Baranchikov, Y. N.; Kuzmina, N. A.

2012-04-01

Regional Siberian studies have already registered climate warming over the last half a century (1960-2010). Our analysis showed that winters are already 2-3°C warmer in the north and 1-2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1-2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10-20% in the south, promoting local drying in already dry landscapes. Our goal was to summarize results of research we have done for the last decade in the context of climate warming and its consequences for biosystems in Central Siberia. We modeled climate change effects on vegetation shifts, on forest composition and agriculture change, on the insect Siberian moth (Dendrolimus suprans sibiricus Tschetv) and pathogene (Lophodermium pinastri Chev) ranges in Central Siberia for a century (1960-2050) based on historical climate data and GCM-predicted data. Principal results are: In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over 50% of central Siberia due to the dryer climate by 2080. Permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats; At least half of central Siberia is predicted to be climatically suitable for agriculture at the end of the century although potential croplands would be limited by the availability of suitable soils agriculture in central Siberia would likely benefit from climate warming Crop production may twofold increase as climate warms during the century; traditional crops (grain, potato

Classification of boreal forest by satellite and inventory data using neural network approach

NASA Astrophysics Data System (ADS)

Romanov, A. A.

2012-12-01

The main objective of this research was to develop methodology for boreal (Siberian Taiga) land cover classification in a high accuracy level. The study area covers the territories of Central Siberian several parts along the Yenisei River (60-62 degrees North Latitude): the right bank includes mixed forest and dark taiga, the left - pine forests; so were taken as a high heterogeneity and statistically equal surfaces concerning spectral characteristics. Two main types of data were used: time series of middle spatial resolution satellite images (Landsat 5, 7 and SPOT4) and inventory datasets from the nature fieldworks (used for training samples sets preparation). Method of collecting field datasets included a short botany description (type/species of vegetation, density, compactness of the crowns, individual height and max/min diameters representative of each type, surface altitude of the plot), at the same time the geometric characteristic of each training sample unit corresponded to the spatial resolution of satellite images and geo-referenced (prepared datasets both of the preliminary processing and verification). The network of test plots was planned as irregular and determined by the landscape oriented approach. The main focus of the thematic data processing has been allocated for the use of neural networks (fuzzy logic inc.); therefore, the results of field studies have been converting input parameter of type / species of vegetation cover of each unit and the degree of variability. Proposed approach involves the processing of time series separately for each image mainly for the verification: shooting parameters taken into consideration (time, albedo) and thus expected to assess the quality of mapping. So the input variables for the networks were sensor bands, surface altitude, solar angels and land surface temperature (for a few experiments); also given attention to the formation of the formula class on the basis of statistical pre-processing of results of

Monitoring seasonal state and mapping species in Alaskan taiga using imaging radar as input to CO[sub 2] flux models

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

Way, J.B.; Rignot, E.; McDonald, K.

1993-06-01

Changes in the seasonal CO[sub 2] flux of the boreal forests may result from increased atmospheric CO[sub 2] concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 duringmore » spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO[sub 2] flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO[sub 2] flux is presented. CO[sub 2] flux maps are generated from which areal estimates of CO[sub 2] flux are derived. This work was carried out at the Jet Propulsion Laboratory under contract to the NASA.« less

[Estimation of the biological age in males of the taiga tick (Ixodes persulcatus: Ixodinae) by fat reserves in the midgut].

PubMed

Grigor'eva, L A

2012-01-01

Some criteria for the estimation of the biological and calendar age by the fat storage in midgut cells of Ixodes persulcatus males were established on the basis of examination of ticks from the laboratory culture.

The influence of spruce on acidity and nutrient content in soils of Northern Taiga dwarf shrub-green moss spruce forests

NASA Astrophysics Data System (ADS)

Orlova, M. A.; Lukina, N. V.; Smirnov, V. E.; Artemkina, N. A.

2016-11-01

Presently, among the works considering the influence of forest trees on soil properties, the idea that spruce ( Picea abies) promotes the acidification of soils predominates. The aim of this work is to assess the effects of spruce trees of different ages and Kraft classes on the acidity and content of available nutrient compounds in the soils under boreal dwarf shrub-green moss spruce forests by the example of forest soils in the Kola Peninsula. The soils are typical iron-illuvial podzols (Albic Rustic Podzols (Arenic)). Three probable ways of developing soils under spruce forests with the moss-dwarf shrub ground cover are considered. The soils under windfall-soil complexes of flat mesodepressions present the initial status. The acidity of organic soil horizons from the initial stage of mesodepression overgrowth to the formation of adult trees changed nonlinearly: the soil acidity reached its maximum under the 30-40-year-old trees and decreased under the trees older than 100 years. The contents of nitrogen and available nutrients increased. The acidity of the mineral soil horizons under the trees at the ages of 110-135 and 190-220 years was comparable, but higher than that under the 30-40-year-old trees. The differences in the strength and trends of the trees' effect on the soils are explained by the age of spruce trees and their belonging to different Kraft classes.

Origin and causes of the mammoth steppe: a story of cloud cover, woolly mammal tooth pits, buckles, and inside-out Beringia

NASA Astrophysics Data System (ADS)

Dale Guthrie, R.

2001-01-01

To account for the vastness of the northern arid steppes during Glacial episodes, I propose the proximate key variable was simply frequent clear skies. This hitherto under-emphasized point is the hub which best explains many questions. Low maritime cloud cover best accounts for today's tundra, and in a related way, the cloudy Polar Front accounts for the whole of the taiga. Even during Glacial maxima, the proximity of the sea to the Bering isthmus created intermittent maritime cloud cover. This regional cloud cover produced an ecological interruption, or buckle, of the arid steppe belt. While this Beringian mesic buckle did not serve as an intercontinental ecological barrier to most steppe-adapted species, it does seem to have limited the distributions of woolly rhinos, camels, American kiangs, short-faced bears, badgers, and some others. At the beginning of the Holocene, this narrow refugium seems to have been a source of some mesic-adapted species which colonized westward into the now tundra vegetation of northern Asia and eastward into northern North America. This Holocene expansion from a limited and regional Pleistocene refugium created our present misconceptions about Beringia. The mid-strait mesic ecological conditions were the exception to the more extensive, arid-adapted, communities of the Mammoth Steppe.

Microbiological transformation of carbon and nitrogen compounds in forest soils of Central Evenkia

NASA Astrophysics Data System (ADS)

Sorokin, N. D.; Aleksandrov, D. E.; Grodnitskaya, I. D.; Evgrafova, S. Yu.

2017-04-01

It has been found that the total productivity of bacteria and micromycetes in the 0- to 50-cm layer of homogeneous cryozems (Cryosols) on slopes of northern and southern exposures varies from 1.2 to 1.4 t/ha, respectively, and the calculated content of microbial carbon varies in the range 0.7-0.9 t/ha. The respiratory activity of the upper soil layer is 2.5-2.6 μg C-CO2/(g h); the potential methane formation capacity reaches 0.13 nmol CH4/(m2 day) for soils on slopes of northern exposure and 0.16 nmol CH4/(m2 day) for slopes of southern exposure. Accumulation of sorbed ammonium is recorded in the range 15-17 mg NH4/100 g soil in summer. The increase of temperature in the upper horizons of soils on slopes of southern exposure by 5°C compared to the northern slopes results in only an insignificant increase in the emission of CO2 and CH4. The accumulation of sorbed ammonium and nitrate nitrogen in homogeneous cryozems during the vegetation period is comparable to that in gray forest soils of the southern taiga subzone of the Middle Siberia.

Temporal and Spatial Wildfire Dynamics of Northern Siberia: Larch Forests and Insect Outbreak Areas

NASA Astrophysics Data System (ADS)

Kharuk, Viacheslav; Antamoshkina, Olga; Ponomarev, Eugene

2017-04-01

Wildfire number and burned area temporal dynamics within all of Siberia and along a south-north transect in central Siberia (45 - 73°N) were studied based on NOAA/AVHRR and Terra/MODIS data and field measurements for the period since 1996. In addition, fire return interval along the south-north transect was analyzed. Third, pest outbreak (Siberian silkmoth) impact on the wildfires was studied. Both, number of forest fires and burned area in Siberia increased during recent decades. Significant correlations were found between forest fires, burned areas and air temperature (r = 0.5) and drought index (SPEI) (r = -0.43). Within larch stands along the transect wildfire frequency was strongly correlated with incoming solar radiation (r = 0.91). Fire danger period length decreased linearly from south to north along the transect. Fire return interval increased from 80 years at 62°N to 200 years at the Arctic Circle (66°33'N), and to about 300 years near the northern limit of closed forest stands ( 71+°N). That increase was negatively correlated with incoming solar radiation (r = -0.95). Siberian silkmoth outbreaks leads to an order of magnitude increase in burned area and fire frequency. Multiple fires turns former "dark needle conifer" taiga into grass and bush communities for decades.

New data on the natural environment of the Middle and Late Neopleistocene interglacial periods in the east of the European Subarctic Region of Russia

NASA Astrophysics Data System (ADS)

Andreicheva, L. N.; Marchenko-Vagapova, T. I.

2017-11-01

The data obtained from investigation of the Middle and Late Neopleistocene lake sediments in the European Subarctic Region of Russia are reported. Chirva, Rodionovo (Scklov), Sula (Mikulino), and Byzovaya (Leningrad) sediments were subject to palynological analysis and investigation of particle size distribution and mineral composition. The spore-pollen spectra of the Chirva sediments demonstrate two climatic optima: the lower optimum is dominated by the pollen of Pinus sylvestris and broad-leaved species (up to 10%); the upper optimum is dominated by Picea sp. and Pinus sylvestris, while the pollen of Picea sect. Omorica and broad-leaved species are sporadic. The Rodionovo flora is characterized by a more xerophilous composition relative to the Chirva flora and a higher pollen content of pine, birch, wormseed plants, and wormwood. The climatic optimum of the Sula interglacial is distinguished by boreal vegetation, including spruce, birch, and birch-spruce forests with sparse broad-leaved species. The Byzovaya interstadial is marked by seven stages of changes in the vegetation: from tundra and forest-tundra communities to taiga forests with some broad-leaved species. The natural climatic sedimentation conditions in the Middle and Late Neopleistocene interglacial periods are reconstructed. The mineral composition of sediments was largely formed owing to underlying deposits.

Climatic warming above the Arctic Circle: are there trends in timing and length of the thermal growing season in Murmansk Region (Russia) between 1951 and 2012?

PubMed

Blinova, Ilona; Chmielewski, Frank-Michael

2015-06-01

Anomalies in the timing of the thermal growing season have become obvious in the NE part of Fennoscandia since 2000. They are in accordance with climatic changes reported for Europe and Fennoscandia. The actual length of the growing season reached 120 days on average, onset on 30 May and ending on 27 September (1981-2010). Shifts in the timing of the growing season and its mean prolongation by 18.5 days/62a are demonstrated for Murmansk Region (1951-2012). In this period, the onset of the growing season advanced by 7.1 days/62a, while the end was extended by 11.4 days/62a. The delay in the end of the growing season is similar to the entire Fennoscandian pattern but it has not been detected in the rest of Europe. The regional pattern of climatic regimes in Murmansk Region remained stable in comparison with earlier climatic maps (1971). However, the actual shifts in the timing of the growing season were more pronounced in colder (oceanic and mountainous) parts. Recent climatic trends could influence the retreat of the tundra zone and changes in the forest line. Losses of tundra biodiversity and enrichment of the northern taiga by southern species could be expected from present climatic trends.

Factors Affecting Elevated Arsenic and Methyl Mercury Concentrations in Small Shield Lakes Surrounding Gold Mines near the Yellowknife, NT, (Canada) Region

PubMed Central

Houben, Adam James; D’Onofrio, Rebecca; Kokelj, Steven V; Blais, Jules M

2016-01-01

Gold mines in the Yellowknife, NT, region—in particular, the Giant Mine—operated from 1949–99, releasing 237,000 tonnes of waste arsenic trioxide (As2O3) dust, among other compounds, from gold ore extraction and roasting processes. For the first time, we show the geospatial distribution of roaster-derived emissions of several chemical species beyond the mine property on otherwise undisturbed taiga shield lakes within a 25 km radius of the mine, 11 years after its closing. Additionally, we demonstrate that underlying bedrock is not a significant source for the elevated concentrations in overlying surface waters. Aquatic arsenic (As) concentrations are well above guidelines for drinking water (10 μg/L) and protection for aquatic life (5 μg/L), ranging up to 136 μg/L in lakes within 4 km from the mine, to 2.0 μg/L in lakes 24 km away. High conversion ratios of methyl mercury were shown in lakes near the roaster stack as well, with MeHg concentrations reaching 44% of total mercury. The risk of elevated exposures by these metals is significant, as many lakes used for recreation and fishing near the City of Yellowknife are within this radius of elevated As and methyl Hg concentrations. PMID:27050658

Ecological Structure of Recent and Last Glacial Mammalian Faunas in Northern Eurasia: The Case of Altai-Sayan Refugium

PubMed Central

Pavelková Řičánková, Věra; Robovský, Jan; Riegert, Jan

2014-01-01

Pleistocene mammalian communities display unique features which differ from present-day faunas. The paleocommunities were characterized by the extraordinarily large body size of herbivores and predators and by their unique structure consisting of species now inhabiting geographically and ecologically distinct natural zones. These features were probably the result of the unique environmental conditions of ice age ecosystems. To analyze the ecological structure of Last Glacial and Recent mammal communities we classified the species into biome and trophic-size categories, using Principal Component analysis. We found a marked similarity in ecological structure between Recent eastern Altai-Sayan mammalian assemblages and comparable Pleistocene faunas. The composition of Last Glacial and Recent eastern Altai-Sayan assemblages were characterized by the occurrence of large herbivore and predator species associated with steppe, desert and alpine biomes. These three modern biomes harbor most of the surviving Pleistocene mammals. None of the analyzed Palearctic Last Glacial faunas showed affinity to the temperate forest, taiga, or tundra biome. The Eastern part of the Altai-Sayan region could be considered a refugium of the Last Glacial-like mammalian assemblages. Glacial fauna seems to persist up to present in those areas where the forest belt does not separate alpine vegetation from the steppes and deserts. PMID:24454791

Soil factors of ecosystems' disturbance risk reduction under the impact of rocket fuel

NASA Astrophysics Data System (ADS)

Krechetov, Pavel; Koroleva, Tatyana; Sharapova, Anna; Chernitsova, Olga

2016-04-01

Environmental impacts occur at all stages of space rocket launch. One of the most dangerous consequences of a missile launch is pollution by components of rocket fuels ((unsymmetrical dimethylhydrazine (UDMH)). The areas subjected to falls of the used stages of carrier rockets launched from the Baikonur cosmodrome occupy thousands of square kilometers of different natural landscapes: from dry steppes of Kazakhstan to the taiga of West Siberia and mountains of the Altai-Sayany region. The study aims at assessing the environmental risk of adverse effects of rocket fuel on the soil. Experimental studies have been performed on soil and rock samples with specified parameters of the material composition. The effect of organic matter, acid-base properties, particle size distribution, and mineralogy on the decrease in the concentration of UDMH in equilibrium solutions has been studied. It has been found that the soil factors are arranged in the following series according to the effect on UDMH mobility: acid-base properties > organic matter content >clay fraction mineralogy > particle size distribution. The estimation of the rate of self-purification of contaminated soil is carried out. Experimental study of the behavior of UDMH in soil allowed to define a model for calculating critical loads of UDMH in terrestrial ecosystems.

Tree growth and vegetation activity at the ecosystem-scale in the eastern Mediterranean

NASA Astrophysics Data System (ADS)

Coulthard, Bethany L.; Touchan, Ramzi; Anchukaitis, Kevin J.; Meko, David M.; Sivrikaya, Fatih

2017-08-01

Linking annual tree growth with remotely-sensed terrestrial vegetation indices provides a basis for using tree rings as proxies for ecosystem primary productivity over large spatial and long temporal scales. In contrast with most previous tree ring/remote sensing studies that have focused on temperature-limited boreal and taiga environments, here we compare the normalized difference vegetation index (NDVI) with a network of Pinus brutia tree ring width chronologies collected along ecological gradients in semiarid Cyprus, where both radial tree growth and broader vegetation activity are controlled by drought. We find that the interaction between precipitation, elevation, and land-cover type generate a relationship between radial tree growth and NDVI. While tree ring chronologies at higher-elevation forested sites do not exhibit climate-driven linkages with NDVI, chronologies at lower-elevation dry sites are strongly correlated with NDVI during the winter precipitation season. At lower-elevation sites, land cover is dominated by grasslands and shrublands and tree ring widths operate as a proxy for ecosystem-scale vegetation activity. Tree rings can therefore be used to reconstruct productivity in water-limited grasslands and shrublands, where future drought stress is expected to alter the global carbon cycle, biodiversity, and ecosystem functioning in the 21st century.

The transformation of vegetation vertical zonality affected by anthropogenic impact in East Fennoscandia (Russia)

NASA Astrophysics Data System (ADS)

Sidorik, Vadim; Miulgauzen, Daria

2017-04-01

Ecosystems of East Fennoscandia have been affected by intensive anthropogenic influence that resulted in their significant transformation. Study of ecosystems in the framework of vegetation vertical zonality disturbance as well as its recovery allows to understand the trends of anthropogenically induced changes. The aim of the present research is the comparative analysis of vegetation vertical zonality of the two uplands in East Fennoscandia which may be considered as unaffected and affected by anthropogenic impact. The objects of key studies carried out in the north-west of Kola Peninsula in the vicinity of the Pechenganikel Mining and Metallurgical Plant are represented by ecosystems of Kalkupya (h 357 m) and Hangaslachdenvara (h 284 m) uplands. They are characterized by the similarity in sequence of altitudinal belts due to the position on the northern taiga - forest-tundra boundary. Plant communities of Kalkupya upland have no visible signs of anthropogenic influence, therefore, they can be considered as model ecosystems of the area. The sequence of altitudinal belts is the following: - up to 200 m - pine subshrub and green moss ("zonal") forest replaced by mixed pine and birch forest near the upper boundary; - 200-300 m - birch crooked subshrub wood; - above 300 m - tundra subshrub and lichen communities. Ecosystems of Hangaslachdenvara upland have been damaged by air pollution (SO2, Ni, Cu emissions) of the Pechenganikel Plant. This impact has led to plant community suppression and formation of barren lands. Besides the soil cover was significantly disturbed, especially upper horizons. Burying of soil profiles, represented by Podzols (WRB, 2015), also manifested itself in the exploited part of the area. The vegetation cover of Hangaslachdenvara upland is the following: - up to 130 m - birch and aspen subshrub and grass forest instead of pine forest ("zonal"); - 130-200 m - barren lands instead of pine forest ("zonal"); - above 200 m - barren lands instead of

Reconstructing the landscape structure of the Lena-Angara interfluve (south part of Eastern Siberia)

NASA Astrophysics Data System (ADS)

Atutova, Zhanna

2015-04-01

Historical-geographical reconstructions of the landscape structure of territories developed in the remote past constitute the necessary element in the chain of research into the dynamics and the degree of transformation of geosystems caused by the influence of the natural regularities and anthropogenic factors. The objective of this study is to determine the specific features of the territory of the Lena-Angara interfluve in the late 19th - early 20th centuries in the interest of a subsequent different-time comparative analysis of the landscape situation. An analysis of the features inherent in the functioning of the geosystems of the Lena-Angara interfluve was made by using, as an example, an elevated plateau with the sources of the Kuda river as well as of the Ilga and Kuda rivers. The relief is represented by a tableland with narrow crests of the watersheds, heavily dissected by a dense network of the valleys of rivers. The denudation processes created planate table-shaped elevations and plateaus whose range of absolute altitudes varies between 400 and 1000 m. The analysis of the landscape structure showed that the study territory was the home for mountain-taiga dark-coniferous and deciduous classes of facies. Larch, spruce-larch and, in places, pine-larch subshrub-grass-moss forests grew within the basins of the Ilga and Kulenga rivers. The watershed spaces of the Ilga-Kuda interfluve, and also the slopes of the upper reaches of the Kuda river were occupied by Siberian stone pine and larch-spruce subshrub-moss groups of facies. In spite of the ubiquitous occurrence of taiga-forest ranges, most of them transformed to derivative groups of facies. Forest fires gave impetus to a widespread occurrence of coniferous/small-leaved complexes in burned-over areas. The study area was poorly populated at the period under investigation; therefore, cultivated lands occupied very small territories. The upper reaches of the Kulenga river included small tracts of arable land

Influence of forest stands on soil and ecosystem carbon stocks in the conditions of the European part of Russia

NASA Astrophysics Data System (ADS)

Kaganov, Vladimir

2016-04-01

Forest stands are one of the most important components of ecosystems, both in Russia and around the world and at the same time forest vegetation is able to provide environment-modifying effect on the occupied landscape and, in particular, on the soil cover. Currently, due to the large interest in the carbon cycle, there is a question about the influence of forest vegetation on carbon stocks in ecosystems and in particular in the soil cover. To perform the study we selected 9 objects located in the European part of Russia from the area of the southern taiga to the semi-desert zone: Novgorod region, Kostroma region, Moscow region (2 objects), Penza region, Voronezh region, Volgograd region (2 objects) and Astrakhan region. For studying the influence of forest vegetation on the soil`s carbon, we organized the following experiment scheme: in each of the objects two key sites were selected, so that they originally were in the same soil conditions and the difference between them was only in a course development of vegetation - forest or grass. One part of the experimental sites, presenting forest vegetation, were the restored forests on abandoned lands with the age of 70-200 years. The second part of the experimental sites were artificial forest plantations aged from 60 to 112 years planted on the originally treeless forest-steppe or steppe landscapes. Perennial hayfields, perennial abandoned agricultural landscapes and virgin steppe areas were used as reference sites with grass vegetation. For each forest site we estimated the major carbon pools: phytomass, mortmass (dead wood, dry grass), debris, litter and soil. All data were recalculated using the conversion factors in carbon stocks in t C ha-1. We collected soil samples every 10 cm until the depth of 50 cm, and then at 50-75 and 75-100 cm soil layers. Bulk density and total organic carbon were determined by CHN analyzer. As a result, the soil`s carbon was also calculated into t C ha-1. We found out that the total

(abstract) Monitoring Seasonal State and Mapping Species in Alaskan Taiga Using Imaging Radar as Input to CO(sub 2) Flux Models

NASA Technical Reports Server (NTRS)

Way, J. B.; Rignot, E.; McDonald, K.; Adams, P.; Viereck, L.

1993-01-01

Changes in the seasonal CO(sub 2) flux of the boreal forests may result from increased atmospheric CO(sub 2) concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 during spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO(sub 2) flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO(sub 2) flux is presented. CO(sub 2) flux maps are generated from which areal estimates of CO(sub 2) flux are derived.

[Cyclic processes in the dynamics of the population count of the taiga tick and their relation to weather and climatic conditions].

PubMed

Korotkov, Iu S

1998-01-01

The paper continues the discussion of published materials on the dynamic of Ixodes persulcatus number in mountain forests of the central part of the Krasnoyarsk region during 1958-1990 (Korotkov e. a., 1992). An unstationarity and polycyclicity of examined processus is confirmed. It is shown, that long-term and middle-term quasi-periodical fluctuations of the tick number are determined by successive changing in forest biocenoses going under the influence of respective fluctuations of the climate. The synchronization of climatic and biocenotic processes is complicatedly organized in time and is not indicated phenomenologically. Certain quasi-periodical components in their indices of the tick number and climate are quite different by their amplitude, value of phase displacement, and longevity of terms. However, these structural differences are natural and determined by peculiarities of the response reaction of I. persulcatus to different intensivity of acting factor. This reaction under extreme environment conditions, both minimal and maximal ones, leads to the same result, the decreasing of the vital activity and the tick number.

Fate and effects of crude oil spilled on permafrost terrain. Annual progress report No. 2, Jun 76-Jul 77

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

McFadden, T.; Jenkins, T.; Collins, C.

1977-12-01

A study was initiated in 1975 to evaluate the fate and effects of crude oil spilled on a taiga-covered permafrost site in Alaska. During this second year of the study the logistical portion of the experiments was completed with a spill of hot Prudhoe Bay crude oil in July 1976. This spill was compared with one that took place in February 1976 (reported upon in the first annual progress report). Studies on the differences in the fate of the oil, its effects on the permafrost, and its impact on the biological communities were continued and expanded. Oil moved downslope atmore » a much faster rate during the summer spill than during the winter spill. In the winter the oil cooled and pooled rapidly. The summer spill covered approximately one-third more surface area than did the winter spill in the final configuration, even though the two spills were of almost identical volume. Increases in microbial populations and activities during the months following the spill were evident. Increased counts of bacteria, yeasts, denitrifying bacteria, and petroleum-degrading bacteria following the oil spills were particularly evident. Analysis of the oil's decomposition using gas chromatography techniques indicated that the low molecular weight fractions, methane and ethane, were lost almost immediately after the spill in each case.« less

Interspecific and intraspecific competition as causes of direct and delayed density dependence in a fluctuating vole population

PubMed Central

Hansen, Thomas F.; Stenseth, Nils C.; Henttonen, Heikki; Tast, Johan

1999-01-01

A 3- to 5-year cycle of vole abundances is a characteristic phenomenon in the ecology of northern regions, and their explanation stands as a central theoretical challenge in population ecology. Although many species of voles usually coexist and are in severe competition for food and breeding space, the role of interspecific competition in vole cycles has never been evaluated statistically. After studying community effects on the population dynamics of the gray-sided vole (Clethrionomys rufocanus) in the subarctic birch forest at Kilpisjärvi, Finland, we report statistical results showing that both interspecific and intraspecific effects are important in the direct year-to-year density dependence. However, interspecific effects are not detectable in the 2-year delayed density dependence that is crucial for generating the characteristic cycles. Furthermore, we show that most of the competition takes place during the winter. The results are evaluated against two models of community dynamics. One assumes that the delayed effects are caused by an interaction with a specialist predator, and the other assumes that they are caused by overgrazing food plants. These statistical results show that vole cycles may be generated by a species-specific trophic interaction. The results also suggest that the gray-sided vole may be the focal species in the birch-forest community, as field voles may be in the taiga and as lemmings may be on the tundra. PMID:9927680

Soils of northern spurs of the Cherskii Ridge in the area of the northern pole of cold: Morphology, properties, and classification

NASA Astrophysics Data System (ADS)

Okoneshnikova, M. V.; Desyatkin, R. V.

2017-08-01

The soils in the area of the northern pole of cold located on the interfluve between the Yana and Adycha rivers within the spurs of Kisilyakh Ridge included in the mountain system of Cherskii Ridge have been studied for the first time. The profile-genetic approach has been applied to describe the soils and determine their classification position. It is found that the major soil types in this region are the soils of the postlithogenic trunk belonging to the orders of lithozems (Cryic Leptosols), gley soils (Gleyic Skeletic Cryosols), and Al-Fe-humus soils (Spodic Skeletic Cryosols). The ecological ranges of altitudinal zones— the taiga zone with various types of lithozems below 630-700 m a.s.l. and the tundra zone with combinations of gley and nongley cryogenic soils above these heights—have been established. The development of gley or nongley soils is specified by the local orogenic and lithological conditions and slope aspect, which, in turn, control the degree of drainage and the presence and character of permafrost. In the profile of mountainous gley soils (gleyzems) with shallow ice-rich permafrost, cryogenic processes and features typical of the analogues of these soils on plains—cryogenic cracking, cryoturbation, solifluction, thixotropy, oxiaquic features above permafrost, saturation of the soil profile with mobile humus, etc.—are typical.

Alaska Melilotus invasions: Distribution, origin, and susceptibility of plant communities

USGS Publications Warehouse

Conn, J.S.; Beattie, K.L.; Shephard, M.A.; Carlson, M.L.; Lapina, I.; Hebert, M.; Gronquist, R.; Densmore, R.; Rasy, M.

2008-01-01

Melilotus alba and M. officinalis were introduced to Alaska in 1913 as potential forage crops. These species have become naturalized and are now invading large, exotic plant-free regions of Alaska. We determined distributions of M. alba and M. officinalis in Alaska from surveys conducted each summer from 2002 to 2005. Melilotus alba and M. officinalis occurred at 721 and 205 sites, respectively (39,756 total sites surveyed). The northward limit for M. alba and M. officinalis was 67.15??N and 64.87??N, respectively. Both species were strictly associated with soil disturbance. Melilotus alba extended no farther than 15 m from road edges except where M. alba on roadsides met river floodplains and dispersed downriver (Matanuska and Nenana Rivers). Melilotus has now reached the Tanana River, a tributary of the Yukon River. Populations on floodplains were most extensive on braided sections. On the Nenana River, soil characteristics did not differ between where M. alba was growing versus similar areas where it had not yet reached. The pH of river soils (7.9-8.3) was higher than highway soils (7.3). Upland taiga plant communities grow on acid soils which may protect them from invasion by Melilotus, which prefer alkaline soils; however, early succession communities on river floodplains are susceptible because soils are alkaline. ?? 2008 Regents of the University of Colorado.

Consequences of long-term severe industrial pollution for aboveground carbon and nitrogen pools in northern taiga forests at local and regional scales.

PubMed

Manninen, Sirkku; Zverev, Vitali; Bergman, Igor; Kozlov, Mikhail V

2015-12-01

Boreal coniferous forests act as an important sink for atmospheric carbon dioxide. The overall tree carbon (C) sink in the forests of Europe has increased during the past decades, especially due to management and elevated nitrogen (N) deposition; however, industrial atmospheric pollution, primarily sulphur dioxide and heavy metals, still negatively affect forest biomass production at different spatial scales. We report local and regional changes in forest aboveground biomass, C and N concentrations in plant tissues, and C and N pools caused by long-term atmospheric emissions from a large point source, the nickel-copper smelter in Monchegorsk, in north-western Russia. An increase in pollution load (assessed as Cu concentration in forest litter) caused C to increase in foliage but C remained unchanged in wood, while N decreased in foliage and increased in wood, demonstrating strong effects of pollution on resource translocation between green and woody tissues. The aboveground C and N pools were primarily governed by plant biomass, which strongly decreased with an increase in pollution load. In our study sites (located 1.6-39.7 km from the smelter) living aboveground plant biomass was 76 to 4888 gm(-2), and C and N pools ranged 35-2333 g C m(-2) and 0.5-35.1 g N m(-2), respectively. We estimate that the aboveground plant biomass is reduced due to chronic exposure to industrial air pollution over an area of about 107,200 km2, and the total (aboveground and belowground) loss of phytomass C stock amounts to 4.24×10(13) g C. Our results emphasize the need to account for the overall impact of industrial polluters on ecosystem C and N pools when assessing the C and N dynamics in northern boreal forests because of the marked long-term negative effects of their emissions on structure and productivity of plant communities. Copyright © 2015 Elsevier B.V. All rights reserved.

Early Holocene vegetation - climate interactions in the central part of European Russia

NASA Astrophysics Data System (ADS)

Novenko, Elena; Olchev, Alexander

2017-04-01

The new Early Holocene vegetation and climate reconstruction (approximately 10100 -7800 cal. yr. BP) for the forest zone the central European Russia are based on pollen records from three key regions located in taiga, mixed coniferous-broadleaved and broadleaved forest zones. The climatic parameters (the mean annual temperature and precipitation) and total forest coverage during the early Holocene were reconstructed using the Best Modern Analogue technique. Information about moistening conditions was revealed from reconstructions of actual evapotranspiration (ET) and potential evaporation (PET). For calculation of the annual ET and PET rates of the forest landscapes a regression model was applied. The model is based on nonlinear approximations of annual values of ET and PET provided by the Levenberg-Marquardt method using the results of numerical simulations of ET and PET carried out by a Mixfor-SVAT model for the forests with different species compositions under various thermal and moistening conditions. Mixfor-SVAT is an one-dimensional model of the energy, H2O and CO2 exchange between vertically structured mono- and multi-specific forest stands and the atmosphere (Olchev et al., 2002). Obtained results showed that the considered period was characterized by relatively low air temperatures and high precipitation compared with modern conditions. Analysis of the long-term pattern of the mean annual temperature for all three regions reveal two synchronous significant cooling periods observed in 9100-9300 cal. yr. BP and 8100-8500 cal. yr. BP as well as rapid growth of the air temperature in 8100-7800 cal. yr. BP, when the annual temperatures increased by 3°C during about 300 years. The cooling phase of 8100-8500 cal. yr. BP could be corresponded to the distinct "8.2 ka event" widely recorded across Europe. Periods of climate warming are coincided with periods of precipitation rise whereas the cool phases are characterized by its decrease. The lowest ET and PET rates

Chapter 4. Recent epidemiology of tick-borne encephalitis an effect of climate change?

PubMed

Korenberg, E I

2009-01-01

Consideration is given to the opinion of some specialists that the rise in tick-borne encephalitis (TBE) morbidity at the turn of the century has been accounted for by new features of TBE epidemiology as well as by global climate change. It is shown that neither the reputed current expansion of the ranges of main TBE vectors, the taiga (Ixodes persulcatus) and sheep (Ixodes ricinus) ticks, nor the significant rise of their abundance and TBE virus prevalence in them are confirmed by any objective data. The concept of recent tick expansion to large cities and human TBE infection in newly formed urban foci disagrees with the facts repeatedly described during the past four decades. There is no reliable information on the expansion of TBE nosological range. The influence of newly formed anthropurgic foci and of changes in the contribution of city dwellers to the general morbidity structure on the current epidemiological situation is estimated. As in the case of any other zoonosis with natural focality, the level of epidemiological manifestation of TBE foci is determined by two main parameters: the intensity of virus circulation in the foci (i.e., their loimopotential) and the frequency of human contact with them. Attention is paid to the character of interaction between these two factors, which accounted for a major outbreak of TBE morbidity at the end of the twentieth century, followed by a long-term decrease in its level.

Tunka-Rex: Status, Plans, and Recent Results

NASA Astrophysics Data System (ADS)

Schröder, F. G.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Kostunin, D.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Wischnewski, R.; Zagorodnikov, A.

2017-03-01

Tunka-Rex, the Tunka Radio extension at the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) in Siberia, has recently been expanded to a total number of 63 SALLA antennas, most of them distributed on an area of one square kilometer. In the first years of operation, Tunka-Rex was solely triggered by the co-located air-Cherenkov array Tunka-133. The correlation of the measurements by both detectors has provided direct experimental proof that radio arrays can measure the position of the shower maximum. The precision achieved so far is 40 g/cm2, and several methodical improvements are under study. Moreover, the cross-comparison of Tunka-Rex and Tunka-133 shows that the energy reconstruction of Tunka-Rex is precise to 15 %, with a total accuracy of 20 % including the absolute energy scale. By using exactly the same calibration source for Tunka-Rex and LOPES, the energy scale of their host experiments, Tunka-133 and KASCADE-Grande, respectively, can be compared even more accurately with a remaining uncertainty of about 10 %. The main goal of Tunka-Rex for the next years is a study of the cosmic-ray mass composition in the energy range above 100 PeV: For this purpose, Tunka-Rex now is triggered also during daytime by the particle detector array Tunka-Grande featuring surface and underground scintillators for electron and muon detection.

Application of territorial GIS to study of natural environment for regions under mining exploitation

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

Kirsanov, A.

1996-07-01

Mineral resources exploitation becomes one of the leading factors of technogenic impact to natural environment. The processes accompanying exploitation lead to changes of geological/geomorphological, engineering/geological, hydrogeological, geochemical and landscape conditions over the large territories surrounded mining exploitation districts. The types of environmental changes and disturbances are stipulated by several reasons such as kind of exploited resources (ore, petroleum, gas, coal, peat, building materials etc.); the ways of extraction (opened by quarry or closed by mine); natural zone (tundra, taiga, steppe, desert etc.). Expressive revelation and control of these environmental changes is impossible without wide using and analysis of various typesmore » and different times materials of airborne and satellite surveys (MASS). They are the basis of system approach to environmental study because of image is the decreased spatial model of territory. For integrated estimation of natural resources and perspectives of its economical profit using, as well as examination of influence of extraction objects to natural environment necessary to involve different data. Only territorial GIS permits to solve the tasks of collection, keeping, processing and analysis of this data as well as to conduct modelling of situations and presentation of information necessary to accept the decision. The core of GIS is the Data base which consists of initial remote sensing and cartographic data allow in completely obtain various information providing of full value and objectivity of investigations.« less

Digital soil map of the Ussuri River basin

NASA Astrophysics Data System (ADS)

Bugaets, A. N.; Pschenichnikova, N. F.; Tereshkina, A. A.; Krasnopeev, S. M.; Gartsman, B. I.; Golodnaya, O. M.; Oznobikhin, V. I.

2017-08-01

On the basis of digital soil, topographic, and geological maps; raster topography model; forestry materials; and literature data, the digital soil map of the Ussuri River basin (24400 km2) was created on a scale of 1: 100000. To digitize the initial paper-based maps and analyze the results, an ESRI ArcGIS Desktop (ArcEditor) v.10.1 (http://www.esri.com) and an open-code SAGA GIS v.2.3 (System for Automated Geoscientific Analyses, http://www.saga-gis.org) were used. The spatial distribution of soil areas on the obtained digital soil map is in agreement with modern cartographic data and the SRTM digital elevation model (SRTM DEM). The regional soil classification developed by G.I. Ivanov was used in the legend to the soil map. The names of soil units were also correlated with the names suggested in the modern Russian soil classification system. The major soil units on the map are at the soil subtypes that reflect the entire vertical spectrum of soils in the south of the Far East of Russia (Primorye region). These are mountainous tundra soils, podzolic soils, brown taiga soils, mountainous brown forest soils, bleached brown soils, meadow-brown soils, meadow gley soils, and floodplain soils). With the help of the spatial analysis function of GIS, the comparison of the particular characteristics of the soil cover with numerical characteristics of the topography, geological composition of catchments, and vegetation cover was performed.

Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments

PubMed Central

He, Ruo; Wooller, Matthew J; Pohlman, John W; Quensen, John; Tiedje, James M; Leigh, Mary Beth

2012-01-01

Methane (CH4) emitted from high-latitude lakes accounts for 2–6% of the global atmospheric CH4 budget. Methanotrophs in lake sediments and water columns mitigate the amount of CH4 that enters the atmosphere, yet their identity and activity in arctic and subarctic lakes are poorly understood. We used stable isotope probing (SIP), quantitative PCR (Q-PCR), pyrosequencing and enrichment cultures to determine the identity and diversity of active aerobic methanotrophs in the water columns and sediments (0–25 cm) from an arctic tundra lake (Lake Qalluuraq) on the north slope of Alaska and a subarctic taiga lake (Lake Killarney) in Alaska's interior. The water column CH4 oxidation potential for these shallow (∼2 m deep) lakes was greatest in hypoxic bottom water from the subarctic lake. The type II methanotroph, Methylocystis, was prevalent in enrichment cultures of planktonic methanotrophs from the water columns. In the sediments, type I methanotrophs (Methylobacter, Methylosoma and Methylomonas) at the sediment-water interface (0–1 cm) were most active in assimilating CH4, whereas the type I methanotroph Methylobacter and/or type II methanotroph Methylocystis contributed substantially to carbon acquisition in the deeper (15–20 cm) sediments. In addition to methanotrophs, an unexpectedly high abundance of methylotrophs also actively utilized CH4-derived carbon. This study provides new insight into the identity and activity of methanotrophs in the sediments and water from high-latitude lakes. PMID:22592821

Palaeodistribution modelling of European vegetation types at the Last Glacial Maximum using modern analogues from Siberia: Prospects and limitations

NASA Astrophysics Data System (ADS)

Janská, Veronika; Jiménez-Alfaro, Borja; Chytrý, Milan; Divíšek, Jan; Anenkhonov, Oleg; Korolyuk, Andrey; Lashchinskyi, Nikolai; Culek, Martin

2017-03-01

We modelled the European distribution of vegetation types at the Last Glacial Maximum (LGM) using present-day data from Siberia, a region hypothesized to be a modern analogue of European glacial climate. Distribution models were calibrated with current climate using 6274 vegetation-plot records surveyed in Siberia. Out of 22 initially used vegetation types, good or moderately good models in terms of statistical validation and expert-based evaluation were computed for 18 types, which were then projected to European climate at the LGM. The resulting distributions were generally consistent with reconstructions based on pollen records and dynamic vegetation models. Spatial predictions were most reliable for steppe, forest-steppe, taiga, tundra, fens and bogs in eastern and central Europe, which had LGM climate more similar to present-day Siberia. The models for western and southern Europe, regions with a lower degree of climatic analogy, were only reliable for mires and steppe vegetation, respectively. Modelling LGM vegetation types for the wetter and warmer regions of Europe would therefore require gathering calibration data from outside Siberia. Our approach adds value to the reconstruction of vegetation at the LGM, which is limited by scarcity of pollen and macrofossil data, suggesting where specific habitats could have occurred. Despite the uncertainties of climatic extrapolations and the difficulty of validating the projections for vegetation types, the integration of palaeodistribution modelling with other approaches has a great potential for improving our understanding of biodiversity patterns during the LGM.

Organic acids and selected nitrogen species for ABLE-3

NASA Technical Reports Server (NTRS)

Talbot, Robert W.

1991-01-01

The NASA Global Tropospheric Experiment (GTE) executed airborne science missions aboard the NASA Wallops Electra (NA429) in the North American high latitude (greater than 45 deg North) atmosphere during Jul. to Aug. 1988 and Jul. to Aug. 1990. These missions were part of GTE's Atmospheric Boundary Layer Experiment (ABLE). The 1988 mission , ABLE-3A, examined the ecosystems of Alaska as a source and/or sink for important tropospheric gases and particles, and gained new information on the chemical composition of the Arctic atmosphere during the summertime. During 1990 the second high latitude mission, ABLE-3B, focused on the Hudson Bay Lowland and Labrador regions of Canada. Both of these missions provided benchmark data sets on atmosphere biosphere exchange and atmospheric chemistry over largely uninhabited regions of North America. In support of the GTE/ABLE-3A and -3B field missions, the University of New Hampshire flew instrumentation aboard the Wallops Electra research aircraft to provide measurements of the trace gases nitric (HNO3), formic (HCOOH), and acetic (CH3COOH) acid. In addition, measurements were conducted to determine the major water soluble ionic composition of the atmospheric aerosol. For ABLE-3B, groundbased measurements of the acidic trace gases were also performed from the NASA micrometerological tower situated at Schefferville, Laborador. These measurements were aimed at assessing dry deposition of acidic gases to the taiga ecosystem in the Laborador region of Canada.

Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments

USGS Publications Warehouse

He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

2012-01-01

Methane (CH4) emitted from high-latitude lakes accounts for 2–6% of the global atmospheric CH4 budget. Methanotrophs in lake sediments and water columns mitigate the amount of CH4 that enters the atmosphere, yet their identity and activity in arctic and subarctic lakes are poorly understood. We used stable isotope probing (SIP), quantitative PCR (Q-PCR), pyrosequencing and enrichment cultures to determine the identity and diversity of active aerobic methanotrophs in the water columns and sediments (0–25 cm) from an arctic tundra lake (Lake Qalluuraq) on the north slope of Alaska and a subarctic taiga lake (Lake Killarney) in Alaska's interior. The water column CH4 oxidation potential for these shallow (~2m deep) lakes was greatest in hypoxic bottom water from the subarctic lake. The type II methanotroph, Methylocystis, was prevalent in enrichment cultures of planktonic methanotrophs from the water columns. In the sediments, type I methanotrophs (Methylobacter, Methylosoma and Methylomonas) at the sediment-water interface (0–1 cm) were most active in assimilating CH4, whereas the type I methanotroph Methylobacter and/or type II methanotroph Methylocystis contributed substantially to carbon acquisition in the deeper (15–20 cm) sediments. In addition to methanotrophs, an unexpectedly high abundance of methylotrophs also actively utilized CH4-derived carbon. This study provides new insight into the identity and activity of methanotrophs in the sediments and water from high-latitude lakes.

Ecophysiological modeling of photosynthesis and carbon allocation to the tree stem in the boreal forest

NASA Astrophysics Data System (ADS)

Gennaretti, Fabio; Gea-Izquierdo, Guillermo; Boucher, Etienne; Berninger, Frank; Arseneault, Dominique; Guiot, Joel

2017-11-01

A better understanding of the coupling between photosynthesis and carbon allocation in the boreal forest, together with its associated environmental factors and mechanistic rules, is crucial to accurately predict boreal forest carbon stocks and fluxes, which are significant components of the global carbon budget. Here, we adapted the MAIDEN ecophysiological forest model to consider important processes for boreal tree species, such as nonlinear acclimation of photosynthesis to temperature changes, canopy development as a function of previous-year climate variables influencing bud formation and the temperature dependence of carbon partition in summer. We tested these modifications in the eastern Canadian taiga using black spruce (Picea mariana (Mill.) B.S.P.) gross primary production and ring width data. MAIDEN explains 90 % of the observed daily gross primary production variability, 73 % of the annual ring width variability and 20-30 % of its high-frequency component (i.e., when decadal trends are removed). The positive effect on stem growth due to climate warming over the last several decades is well captured by the model. In addition, we illustrate how we improve the model with each introduced model adaptation and compare the model results with those of linear response functions. Our results demonstrate that MAIDEN simulates robust relationships with the most important climate variables (those detected by classical response-function analysis) and is a powerful tool for understanding how environmental factors interact with black spruce ecophysiology to influence present-day and future boreal forest carbon fluxes.

Contributions of separate reactions to the acid-base buffering of soils in brook floodplains (Central Forest State Reserve)

NASA Astrophysics Data System (ADS)

Sokolova, T. A.; Tolpeshta, I. I.; Rusakova, E. S.

2016-04-01

The acid-base buffering of gleyic gray-humus soils developed in brook floodplains and undisturbed southern-taiga landscapes has been characterized by the continuous potentiometric titration of soil water suspensions. During the interaction with an acid, the major amount of protons (>80%) is consumed for the displacement of exchangeable bases and the dissolution of Ca oxalates. In the O and AY horizons, Mn compounds make the major contribution (2-15%) to the acid buffering. The buffer reactions with the participation of Al compounds make up from 0.5 to 1-2% of the total buffering capacity, and the protonation of the surface OH groups of kaolinite consumes 2-3% of the total buffering capacity. The deprotonation of OH groups on the surface of Fe hydroxides (9-43%), the deprotonation of OH groups on the surface of illite crystals (3-19%), and the dissolution of unidentified aluminosilicates (9-14%) are the most significant buffer reactions whose contributions have been quantified during the interaction with a base. The contribution of the deprotonation of OH groups on the surface of kaolinite particles is lower (1-5%) because of the small specific surface area of this mineral, and that of the dissolution of Fe compounds is insignificant. In the AY horizon, the acid and base buffering of soil in the rhizosphere is higher than beyond the rhizosphere because of the higher contents of organic matter and nonsilicate Fe and Al compounds.

Molecular Detection of 10 of the Most Unwanted Alien Forest Pathogens in Canada Using Real-Time PCR

PubMed Central

Lamarche, Josyanne; Potvin, Amélie; Pelletier, Gervais; Stewart, Don; Feau, Nicolas; Alayon, Dario I. O.; Dale, Angela L.; Coelho, Aaron; Uzunovic, Adnan; Bilodeau, Guillaume J.; Brière, Stephan C.; Hamelin, Richard C.; Tanguay, Philippe

2015-01-01

Invasive alien tree pathogens can cause significant economic losses as well as large-scale damage to natural ecosystems. Early detection to prevent their establishment and spread is an important approach used by several national plant protection organizations (NPPOs). Molecular detection tools targeting 10 of the most unwanted alien forest pathogens in Canada were developed as part of the TAIGA project (http://taigaforesthealth.com/). Forest pathogens were selected following an independent prioritization. Specific TaqMan real-time PCR detection assays were designed to function under homogeneous conditions so that they may be used in 96- or 384-well plate format arrays for high-throughput testing of large numbers of samples against multiple targets. Assays were validated for 1) specificity, 2) sensitivity, 3) precision, and 4) robustness on environmental samples. All assays were highly specific when evaluated against a panel of pure cultures of target and phylogenetically closely-related species. Sensitivity, evaluated by assessing the limit of detection (with a threshold of 95% of positive samples), was found to be between one and ten target gene region copies. Precision or repeatability of each assay revealed a mean coefficient of variation of 3.4%. All assays successfully allowed detection of target pathogen on positive environmental samples, without any non-specific amplification. These molecular detection tools will allow for rapid and reliable detection of 10 of the most unwanted alien forest pathogens in Canada. PMID:26274489

Post fire organic matter biodegradation in permafrost soils: Case study after experimental heating of mineral horizons.

PubMed

Masyagina, O V; Tokareva, I V; Prokushkin, A S

2016-12-15

Periodical ground fires of high frequency in permafrost forest ecosystems of Siberia (Russian Federation) are essential factors determining quantitative and qualitative parameters of permafrost soil organic matter. Specific changes in physical and chemical parameters and microbial activity of permafrost soil mineral horizons of northern taiga larch stands were revealed after heating at high temperatures (150-500°C) used for imitation of different burn intensities. Burning at 150-200°C resulted in decreasing of soil pH, whilst heating at 300-500°C caused increase of pH compare to unheated soils. Water-soluble organic carbon concentration in permafrost soils heated at 150-200°C was much higher than that of unheated soils. All these changes determined soil microbial activity in heated soils. In particular, in soils heated at 300-500°C there was momentary stimulating effect on substrate-induced respiration registered and on basal respiration values in soils burned at 150°C and 300-400°C. Four-month laboratory incubation of permafrost soils heated at different temperatures showed stimulation of microbial activity in first several days after inoculation due to high substrate availability after heating. Then soon after that soil microbial community started to be depleted on substrate because of decreasing water-soluble organic carbon, C and N content and it continued to the end of incubation. Copyright © 2016 Elsevier B.V. All rights reserved.

Late Pleistocene and Holocene vegetation and climate changes in the Lake Baikal region

NASA Astrophysics Data System (ADS)

Demske, D.; Heumann, G.; Granoszewski, W.; Mamakowa, K.; Piotrowska, N.; Bluszcz, A.; Goslar, T.

2003-04-01

Palynological high-resolution records from Lake Baikal sediments document strong vegetational changes during the transitions from an open landscape to Late Glacial shrublands and Holocene forests. For three core sites, investigated within EU-Project CONTINENT, sporomorph concentrates were used for AMS 14C dating of environmental changes. The pollen record from the northern lake site, located in vicinity to the Barguzin Mountains, shows pronounced maxima of Salix and Picea corresponding to late Pleistocene warming. A peak maximum in Alnus fruticosa during the Younger Dryas cooling coincided with low abundance of green algae in the lake and a decline in Picea trees. Fern-rich forests with Picea, Larix and Betula developed during early Holocene. With an abrupt expansion of Pteridium ferns Abies appeared in the northeastern Baikal region, reflecting optimum conditions for dark taiga. Among pines Pinus sibirica prevailed prior to the spread of P. sylvestris. Expansion of pines points to a distinct decrease in precipitation. A palynological sequence from the same site reflects the vegetation development during the last interglacial, with differences indicated by higher abundance of Abies. The upper part of the interglacial record comprises the transition to stadial conditions. Further pollen spectra are probably equivalent to first interstadials of the early glacial period (Zyryansk). Comparison with southern sites, in vicinity to the Selenga Delta and the Khamar-Daban Mountains, reveals that regional and temporal differentiation of Holocene vegetation development and climate conditions was closely related to the distribution of mountain ranges.

[Estimation of the biological age in females of the taiga tick Ixodes persulcatus by changes in the body shape and surface of cuticle].

PubMed

Balashov, Iu S; Grigor'eva, L A; Leonovich, S A

2009-01-01

A method of visual estimation of the biological age of living hungry tick females by visible changes in the depth of marginal groove and the structure of the alloscutum cuticle during natural ageing is developed. In recently activated individuals, the body is convex and the marginal groove is exposed, demonstrating distinctly visible cuticular microfolds (Figs 1-4). In attenuated ticks, the body is flattened and marginal fold overlays the marginal groove, concealing cuticular microfolds (Figs 5-8).

A Summer View of Russia's Lena Delta and Olenek

NASA Technical Reports Server (NTRS)

2004-01-01

These views of the Russian Arctic were acquired by NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument on July 11, 2004, when the brief arctic summer had transformed the frozen tundra and the thousands of lakes, channels, and rivers of the Lena Delta into a fertile wetland, and when the usual blanket of thick snow had melted from the vast plains and taiga forests. This set of three images cover an area in the northern part of the Eastern Siberian Sakha Republic. The Olenek River wends northeast from the bottom of the images to the upper left, and the top portions of the images are dominated by the delta into which the mighty Lena River empties when it reaches the Laptev Sea. At left is a natural color image from MISR's nadir (vertical-viewing) camera, in which the rivers appear murky due to the presence of sediment, and photosynthetically-active vegetation appears green. The center image is also from MISR's nadir camera, but is a false color view in which the predominant red color is due to the brightness of vegetation at near-infrared wavelengths. The most photosynthetically active parts of this area are the Lena Delta, in the lower half of the image, and throughout the great stretch of land that curves across the Olenek River and extends northeast beyond the relatively barren ranges of the Volyoi mountains (the pale tan-colored area to the right of image center).

The right-hand image is a multi-angle false-color view made from the red band data of the 60o backward, nadir, and 60o forward cameras, displayed as red, green and blue, respectively. Water appears blue in this image because sun glitter makes smooth, wet surfaces look brighter at the forward camera's view angle. Much of the landscape and many low clouds appear purple since these surfaces are both forward and backward scattering, and clouds that are further from the surface appear in a different spot for each view angle, creating a rainbow-like appearance. However, the vegetated

Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

NASA Astrophysics Data System (ADS)

Mackay, Anson W.; Bezrukova, Elena V.; Leng, Melanie J.; Meaney, Miriam; Nunes, Ana; Piotrowska, Natalia; Self, Angela; Shchetnikov, Alexander; Shilland, Ewan; Tarasov, Pavel; Wang, Luo; White, Dustin

2012-05-01

were also significant, but considerably less important. The potential importance of climate and biome development (tundra, steppe, cold deciduous forest and taiga) on different trophic levels (i.e. chironomid and diatom communities) in lake ESM-1 was also assessed using RDA. Climate predictors had a more significant influence on Holocene chironomid assemblages, especially July insolation at 60 °N, estimates of regional precipitation and estimates of northern hemisphere temperature, while only the development of the taiga biome had a significant impact on these primary consumers. Diatom communities also had a small, but significant influence on Holocene chironomid populations, perhaps linked to variation in faunal feeding strategies. In contrast, climatic and biome predictors explained similar amounts of variation in the Holocene diatom assemblage (approximately 20% each), while chironomids themselves as predictors explained just under 7% of diatom variation. Lake acidity was inferred using a diatom inference model. Results suggest that after deglaciation, the lake did not undergo a process of gradual acidification, most likely due to the presence of continuous permafrost and low levels of precipitation, preventing base cations and dissolved organic carbon entering the lake (except for the period between 1.7 and 0.7 ka BP). We conclude that lakes in continental, boreal regions undergo different models of lake ontogeny than oceanic boreal regions. Unlike other regions discussed, climate is a more important driver of ecosystem change than catchment changes. We also demonstrate that the start of the period coincident with the onset of the Little Ice Age resulted in important thresholds crossed in catchment vegetation and aquatic communities.

Complexation humic substances of soils with metal ions as the main way migration of matals from soil to water

NASA Astrophysics Data System (ADS)

Dinu, Marina

2013-04-01

northern taiga soils; (2) similar amounts of oxygen bearing fragments, hydrocarbon constituents, and nitrogen bearing components in the mixed forest zones; (3) occurrence of aromatic and aliphatic hydrocarbons in HM of steppe soils. The HM functional characteristics influence substantially the stability constants of complexes with metal ions and complex stoichiometry: Fe(III)>Cu(II)>Pb(II)>Al(III)>Co(II)>Ni(II)>Cd(II)>Zn(II)>Cr(III)>Mg(II)>Sr(II)>Ca(II)>Mn(II) - northern taiga soils; Cu(II)>Fe(III)>Al(III)>Ni(II)>Zn(II)>Pb(II)>Co(II)>Cd(II)>Sr(II)>Mn(II)>Cr(III)>Ca(II)>Mg(II) - mixed forest zones; Fe(III)>Cu(II)>Al(III)>Pb(II)>Ni(II)>Zn(II)>Co(II)>Ca(II)>Cd(II)>Sr(II)>Mg(II)>Cr(III)>Mn(II) - steppe soils. 1. T.I. Moiseenko, L.P. Kudryavtseva, and N.A. Gashkina, Scattered Element in Surface Land Waters: Technophility, Bioaccumulation, and Ecotoxicology (Nauka, Moscow, 2006) 2. G. M. Varshal, Ext. Abstr. Doct. Dis. Chem. (Inst. Geokh. Analit. Khim. RAN, Moscow, 1994).. 4. D.S. Orlov, Humic Acids (MGU, Moscow, 1986) 5. D.V. Kovalevsky, Ext. Abstr. Cand. Dis. Chem. (MGU, Moscow, 1998). 6. I.A. Linnik and B. I. Nabivanets, Metal Migration Forms in Surface Fresh Waters (Gidrometizdat, Leningrad, 1985) 7. Hartley, F., Burgess, C., and Alcoc, R., Solution Equilibria (Ellis Horwood, Chichester (UK), 1980). 8. Yu. Yu. Lur'e, Reference Book of Physicochemical Values (Nauka, Moscow, 2000)

Spatial-temporal variability in GHG fluxes and their functional interpretation in RusFluxNet

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Meshalkina, Julia; Sarzhanov, Dmitriy; Mazirov, Ilia; Yaroslavtsev, Alex; Komarova, Tatiana; Tikhonova, Maria

2016-04-01

High spatial and temporal variability is mutual feature for most modern boreal landscapes in the European Territory of Russia. This variability is result of their relatively young natural and land-use age with very complicated development stories. RusFluxNet includes a functionally-zonal set of representative natural, agricultural and urban ecosystems from the Central Forest Reserve in the north till the Central Chernozemic Reserve in the south (more than 1000 km distance). Especial attention has been traditionally given to their soil cover and land-use detailed variability, morphogenetic and functional dynamics. Central Forest Biosphere Reserve (360 km to North-West from Moscow) is the principal southern-taiga one in the European territory of Russia with long history of mature spruce ecosystem structure and dynamics investigation. Our studies (in frame of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) have been concentrated on the soil carbon stocks and GHG fluxes spatial variability and dynamics due to dominated there windthrow and fallow-forest successions. In Moscow RTSAU campus gives a good possibility to develop the ecosystem and soil monitoring of GHG fluxes in the comparable sites of urban forest, field crops and lawn ecosystems taking especial attention on their meso- and micro-relief, soil cover patterns and subsoil, vegetation and land-use technologies, temperature and moisture spatial and temporal variability. In the Central Chernozemic Biosphere Reserve and adjacent areas we do the comparative analysis of GHG fluxes and balances in the virgin and mowed meadow-steppe, forest, pasture, cropland and three types of urban ecosystems with similar subsoil and relief conditions. The carried out researches have shown not only sharp (in 2-5 times) changes in GHG ecosystem and soil fluxes and balances due to seasonal and daily microclimate variation, vegetation and crop development but their essential (in 2-4 times) spatial variability due to

Climate Change in the Russian Altai Mountains and its Influence on Tree Line and Glacier Dynamics

NASA Astrophysics Data System (ADS)

Syromyatina, M.; Moskalenko, I.; Ganushkin, D.; Chistyakov, K.

2011-12-01

the average for the period 1986-2004 - about 1,3°C. As tree line against the other belt borders strongly limited by summer temperature its eventual dynamics since the end of the LIA over the Altai were estimated and tree line position at different stages of modern regional warming was reconstructed. Theoretical evaluation shows that mean summer temperature increase of 1.3°C from the end of the LIA causes tree line to rise maximum by 180-280 m in different localities of the Altai. Glacial complexes of mountain massifs Mongun-Taiga, Tavan-Boghd-Ola, Turgeni-Nuru and Harhira-Nuru located in the South-Eastern Altai are represented by small glaciers mostly on northern and eastern leeward slopes. Being situated in region with dry climatic conditions (250-400 mm/year) glaciers survive only in negative forms of relief with high concentration of snow. Accumulation coefficient is mainly from 2 to 3, and on cirque glaciers is from 6 to 8. Now glaciers retreat rapidly (17% of area loss for the period of 1995-2010 for Mongun-Taiga, 12% in 2002-2009 for Tavan-Boghd-Ola), especially valley glaciers (2-10 m/yr), the number of glaciers increase due to disintegration of larger glaciers. Small forms of glaciation disappear or transform into snow patches and rock glaciers.

MODELLING HYDROLOGY AND SILICON-CARBON INTERACTIONS IN TAIGA AND TUNDRA BIOMES FROM A LANDSCAPE PERSPECTIVE &FRAC34; IMPLICATIONS FOR GLOBAL WARMING FEEDBACKS. (R830882)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Validation of the Daily Passive Microwave Snow Depth Products Over Northern China

NASA Astrophysics Data System (ADS)

Qiao, D.; Li, Z.; Wang, N.; Zhou, J.; Zhang, P.; Gao, S.

2018-04-01

Passive microwave sensors have the capability to provide information on snow depth (SD), which is critically important for hydrological modeling and water resource management. However, the different algorithms used to produce SD products lead to discrepancies in the data. To determine which products might be most suitable for Northern China, this paper assesses the accuracy of the existing snow depth products in the period of 2002-2011. By comparing three daily snow depth products, including NSIDC, WESTDC and ESA Globsnow, with snow cover product and meteorological stations data, the accuracies of the different SD products are analyzed for different snow class and forest cover fraction. The results show that comparison between snow cover derived from snow depth of NSIDC, ESA GlobSnow and WESTDC with snow cover product shows that accuracy of WESTDC and ESA GlobSnow in snow cover detecting can reach 0.70. Compared to meteorological stations data below 20 cm, NSIDC consistently overestimate, WESTDC and ESA Globsnow underestimate, furthermore the product from WESTDC is superior to the others. The three products have the same tendency of significant undervaluation over 20 cm. The WESTDC is superior to the ESA Globsnow and NSIDC in non-forest regions, whereas the ESA GlobSnow estimate is superior to the WESTDC and NSIDC in forest regions. As for the prairie and alpine snow, WESTDC has smaller bias and RMSE, meanwhile Globsnow has advantages in the snow depth retrieval in tundra and taiga snow. Therefore, we should choose the more suitable snow depth products according to different needs.

Organic matter compositions of rivers draining into Hudson Bay: Present-day trends and potential as recorders of future climate change

NASA Astrophysics Data System (ADS)

Godin, Pamela; Macdonald, Robie W.; Kuzyk, Zou Zou A.; Goñi, Miguel A.; Stern, Gary A.

2017-07-01

Concentrations and compositions of particulate and dissolved organic carbon (POC and DOC, respectively) and aromatic compounds including lignin were analyzed in water samples from 17 rivers flowing into Hudson Bay, northern Canada. These rivers incorporate basins to the south with no permafrost to basins in the north with continuous permafrost, and dominant vegetation systems that include Boreal Forest, the Hudson Plains, Taiga Shield, and Tundra. Major latitudinal trends in organic carbon and lignin concentrations and compositions were evident, with both DOC and dissolved lignin concentrations dominating over their particulate counterparts and exhibiting significant correlations with total dissolved and suspended solids, respectively. The composition of lignin reaction products in terms of the syringyl, cinnamyl, and vanillyl compositions indicate mixed sources of vascular land plant-derived organic carbon, with woody gymnosperms contributions dominating in the southern river basins whereas nonwoody angiosperm sources were more important in the most northerly rivers. The composition of nonlignin aromatic compounds, which provides a tracer for nonvascular plant contributions, suggests stronger contributions from Sphagnum mosses to dissolved organic matter in rivers below the tree line, including those with large peat bogs in their basins. Acid/aldehyde ratios of the lignin products together with Δ14C data for DOC in selected rivers indicate that DOC has generally undergone greater alteration than POC. Interestingly, several northern rivers exhibited relatively old DOC according to the Δ14C data suggesting that either old DOC is being released from permafrost or old DOC survives river transport in these rivers.

Biological aspects of terrestrial oil spills: USA CRREL oil research in Alaska, 1970--1974. Final report 1970--1974

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

Deneke, F.J.; McCown, B.H.; Coyne, P.I.

1975-12-01

Knowledge concerning the biological effects of oil pollution on arctic and subarctic terrestrial ecosystems is limited. USA CRREL research personnel conducted investigations from 1970 through 1974 to expand information in this field. Objectives were to: (1) define the ecosystems most sensitive to the presence of crude oil or its refined products, (2) quantify and understand the injury response, and (3) establish time frames for manifestation of damage and natural restorative processes in arctic and subarctic regions. This was accomplished through: (1) surveys of natural oil seepages and past accidential spills in the Arctic and Subarctic, (2) initiation of controlled oilmore » spills and (3) detailed laboratory investigations. Results demonstrated that terrestrial oil spills will to some degree be detrimental to both artic and subarctic plant communities. Degree and longevity of damage will be influenced primarily by the magnitude of the spill, season of occurrence and existing soil moisture content. Rapid recovery of plant communities subjected to spills will occur only if root systems remain relatively unaffected. Damage will be more extensive and long-term when root systems are saturated witl oil. Effects of damage will be manifested gradually over several seasons being influenced by winter stresses. Variation does exist in plant species susceptibility. Carex aquatilis a predominant sedge of the arctic is markedly resistant to crude oil damage. In the taiga Picea mariana is very susceptible. Plant recovery can be enhanced through the application of fertilizer. Fertilization, in addition to its direct effect on plant nutrition, will stimulate microbial decomposition of crude oil. (Author)« less

Phylogeny, Systematics and Biogeography of the Genus Panolis (Lepidoptera: Noctuidae) Based on Morphological and Molecular Evidence

PubMed Central

Wang, Houshuai; Fan, Xiaoling; Owada, Mamoru; Wang, Min; Nylin, Sören

2014-01-01

The genus Panolis is a small group of noctuid moths with six recognized species distributed from Europe to East Asia, and best known for containing the widespread Palearctic pest species P. flammea, the pine beauty moth. However, a reliable classification and robust phylogenetic framework for this group of potentially economic importance are currently lacking. Here, we use morphological and molecular data (mitochondrial genes cytochrome c oxidase subunit I and 16S ribosomal RNA, nuclear gene elongation factor-1 alpha) to reconstruct the phylogeny of this genus, with a comprehensive systematic revision of all recognized species and a new one, P. ningshan sp. nov. The analysis results of maximum parsimony, maximum likelihood and Bayesian inferring methods for the combined morphological and molecular data sets are highly congruent, resulting in a robust phylogeny and identification of two clear species groups, i.e., the P. flammea species group and the P. exquisita species group. We also estimate the divergence times of Panolis moths using two conventional mutation rates for the arthropod mitochondrial COI gene with a comparison of two molecular clock models, as well as reconstruct their ancestral areas. Our results suggest that 1) Panolis is a young clade, originating from the Oriental region in China in the Late Miocene (6–10Mya), with an ancestral species in the P. flammea group extending northward to the Palearctic region some 3–6 Mya; 2) there is a clear possibility for a representative of the Palearctic clade to become established as an invasive species in the Nearctic taiga. PMID:24603596

Gyrfalcon (Falco rusticolus) in Yakutia: Distribution, nesting areas, and features of nutrition

USGS Publications Warehouse

Labutin, Yu. V.; Ellis, D.H.

2006-01-01

In Yakutia, gyrfalcon nests in tundra, forest-tundra, and taiga and may occur in the northeastern and, sometimes, in the northwestern parts, being almost absent or occasional over the large area separating these regions. The southern boundary of the nesting site is nowhere below 64 degrees N. In central Yakutia, gyrfalcon was suggested to be met as a visitant or migratory species. The long-term studies showed that this species occurred there in all the seasons, including winter periods. This fact became a reason to consider the bird as a migratory and wintering (not always) species, despite its repeated comings to inhabited localities that indicated difficulties in birds during winter periods. There are about 30 and 6 species of birds and mammals, respectively, in the gyrfalcon diet in Yakutia. The prevalence of birds is evident (65.4 to 91.3%). In the composition of food species, the share of willow and rock ptamigans is high everywhere, although in the Lower Kolyma tundra, they give way to ducks (19.2 and 30.7%, respectively). Ptamigans as an diet item seems to be of particular importance for the survival of the species. Gyrfalcons prey birds of medium size, such as ptamigans, ducks, and sandpipers. Large (geese. caterpillars) and small (small passerines) birds become gyrfalcon's prey less often. Species of open and semi-open habitats are mostly preferable among mammals. Drastic changes in the forage reserves of gyrfalcon are one of the most serious causes leading to the changes in its number and participation in the reproductive cycles.

Examining the role of dissolved organic nitrogen in stream ecosystems across biomes and Critical Zone gradients

NASA Astrophysics Data System (ADS)

Wymore, A.; Rodriguez-Cardona, B.; Coble, A. A.; Potter, J.; Lopez Lloreda, C.; Perez Rivera, K.; De Jesus Roman, A.; Bernal, S.; Martí Roca, E.; Kram, P.; Hruska, J.; Prokishkin, A. S.; McDowell, W. H.

2016-12-01

Watershed nitrogen exports are often dominated by dissolved organic nitrogen (DON); yet, little is known about the role ambient DON plays in ecosystems. As an organic nutrient, DON may serve as either an energy source or as a nutrient source. One hypothesized control on DON is nitrate (NO3-) availability. Here we examine the interaction of NO3- and DON in streams across temperate forests, tropical rainforests, and Mediterranean and taiga biomes. Experimental streams also drain contrasting Critical Zones which provide gradients of vegetation, soil type and lithology (e.g. volcaniclastic, granitic, ultramafic, Siberian Traps Flood Basalt) in which to explore how the architecture of the Critical Zone affects microbial biogeochemical reactions. Streams ranged in background dissolved organic carbon (DOC) concentration (1-50 mg C/L) and DOC: NO3- ratios (10-2000). We performed a series of ecosystem-scale NO3- additions in multiple streams within each environment and measured the change in DON concentration. Results demonstrate that there is considerable temporal and spatial variation across systems with DON both increasing and decreasing in response to NO3- addition. Ecologically this suggests that DON can serve as both a nutrient source and an energy source to aquatic microbial communities. In contrast, DOC concentrations rarely changed in response to NO3- additions suggesting that the N-rich fraction of the ambient dissolved organic matter pool is more bioreactive than the C-rich fraction. Contrasting responses of the DON and DOC pools indicate different mechanisms controlling their respective cycling. It is likely that DON plays a larger role in ecosystems than previously recognized.

Quantification of uncertainties in global grazing systems assessment

NASA Astrophysics Data System (ADS)

Fetzel, T.; Havlik, P.; Herrero, M.; Kaplan, J. O.; Kastner, T.; Kroisleitner, C.; Rolinski, S.; Searchinger, T.; Van Bodegom, P. M.; Wirsenius, S.; Erb, K.-H.

2017-07-01

Livestock systems play a key role in global sustainability challenges like food security and climate change, yet many unknowns and large uncertainties prevail. We present a systematic, spatially explicit assessment of uncertainties related to grazing intensity (GI), a key metric for assessing ecological impacts of grazing, by combining existing data sets on (a) grazing feed intake, (b) the spatial distribution of livestock, (c) the extent of grazing land, and (d) its net primary productivity (NPP). An analysis of the resulting 96 maps implies that on average 15% of the grazing land NPP is consumed by livestock. GI is low in most of the world's grazing lands, but hotspots of very high GI prevail in 1% of the total grazing area. The agreement between GI maps is good on one fifth of the world's grazing area, while on the remainder, it is low to very low. Largest uncertainties are found in global drylands and where grazing land bears trees (e.g., the Amazon basin or the Taiga belt). In some regions like India or Western Europe, massive uncertainties even result in GI > 100% estimates. Our sensitivity analysis indicates that the input data for NPP, animal distribution, and grazing area contribute about equally to the total variability in GI maps, while grazing feed intake is a less critical variable. We argue that a general improvement in quality of the available global level data sets is a precondition for improving the understanding of the role of livestock systems in the context of global environmental change or food security.

Fir Decline and Mortality in the Southern Siberian Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

2016-01-01

Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata))were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (1825),convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width(TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies)have a high impact on current TRW (r 0.600.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest steppe)and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

Transformation of ecofunctional parameters of soil microbial cenoses in clearings for power transmission lines in Central Siberia

NASA Astrophysics Data System (ADS)

Bogorodskaya, A. V.; Ponomareva, T. V.; Efimov, D. Yu.; Shishikin, A. S.

2017-06-01

Changes in soil microbial processes and phytocenotic parameters were studied in clearings made for power transmission lines in the subtaiga and southern taiga of Central Siberia. In these clearings, secondary meadow communities play the main environmental role. The substitution of meadow vegetation for forest vegetation, the increase in the phytomass by 40-120%, and the transformation of the hydrothermic regime in the clearings led to the intensification of the humus-accumulative process, growth of the humus content, reduction in acidity and oligotrophy of the upper horizons in the gray soils of the meadow communities, and more active microbial mineralization of organic matter. In the humus horizon of the soils under meadows, the microbial biomass (Cmicr) increased by 20-90%, and the intensity of basal respiration became higher by 60-90%. The values of the microbial metabolic quotient were also higher in these soils than in the soils under the native forests. In the 0- to 50-cm layer of the gray soils under the meadows, the total Cmicr reserves were 35-45% greater and amounted to 230-320 g/m3; the total microbial production of CO2 was 1.5-2 times higher than that in the soil of the adjacent forest and reached 770-840 mg CO2-C/m3 h. The predominance of mineralization processes in the soils under meadows in the clearings reflected changes in edaphic and trophic conditions of the soils and testified to an active inclusion of the herb falloff into the biological cycle.

The status of sea ducks in the North Pacific Rim: Toward their conservation and management

USGS Publications Warehouse

Goudie, R. Ian; Brault, Solange; Conant, Bruce; Kondratyev, Alexander V.; Petersen, Margaret R.; Vermeer, Kees; McCabe, Richard E.; Wadsworth, Kelly G.

1994-01-01

Sea ducks (tribe Mergini after Johnsgard 1960) are the most northerly distributed ducks, and species diversity is greatest in the North Pacific. They exploit a diversity of inshore and offshore marine habitats during the non-breeding season, and their use of habitat during breeding varies from coastal through freshwater wetlands of the tundra and taiga (Figure 1, Appendix 1). Non-breeding cohorts frequent marine habitats most of the year. Sea ducks thus are important indicators of the quality of freshwater and marine ecosystems of northern biomes.Of the 17 species discussed in this manuscript, at least 3 are reported to be declining (Appendix 2). However, the basis for many of those assessments is equivocal because there has been little effort to monitor populations. The efforts to more precisely assess their status point to catastrophic declines (Kertell 1991, Stehn et a 1993). Conservation problems related to sea ducks have a long history throughout the Holarctic. For example, the Labrador duck (Camptorhynchus labradorius) became extinct in 1875. (Phillips 1925); common eiders (Somateria mollissima) declined seriously throughout the northern hemisphere (Townsend 1914, Phillips 1925, Doughty 1979); harlequin ducks (Histrionicus histrionicus) experienced declines in Iceland and Greenland (Gudmundsson1971, Salomonson 1950), and more recently have been designated endangered in eastern Canada (Committee On the Status of Endangered Wildlife in Canada 1990). In Russia, all species of eider and harlequin ducks have been closed to sport hunting since 1981, and the Chinese mergansers (Mergus squamatus) presently are extremely rare and fully protected, i.e. category one of the red book (Solomonov 1987).

Influence of vertical and lateral heat transfer on permafrost thaw, peatland landscape transition, and groundwater flow

USGS Publications Warehouse

Kurylyk, Barret L.; Masaki, Masaki; Quinton, William L.; McKenzie, Jeffrey M.; Voss, Clifford I.

2016-01-01

Recent climate change has reduced the spatial extent and thickness of permafrost in many discontinuous permafrost regions. Rapid permafrost thaw is producing distinct landscape changes in the Taiga Plains of the Northwest Territories, Canada. As permafrost bodies underlying forested peat plateaus shrink, the landscape slowly transitions into unforested wetlands. The expansion of wetlands has enhanced the hydrologic connectivity of many watersheds via new surface and near-surface flow paths, and increased streamflow has been observed. Furthermore, the decrease in forested peat plateaus results in a net loss of boreal forest and associated ecosystems. This study investigates fundamental processes that contribute to permafrost thaw by comparing observed and simulated thaw development and landscape transition of a peat plateau-wetland complex in the Northwest Territories, Canada from 1970 to 2012. Measured climate data are first used to drive surface energy balance simulations for the wetland and peat plateau. Near-surface soil temperatures simulated in the surface energy balance model are then applied as the upper boundary condition to a three-dimensional model of subsurface water flow and coupled energy transport with freeze-thaw. Simulation results demonstrate that lateral heat transfer, which is not considered in many permafrost models, can influence permafrost thaw rates. Furthermore, the simulations indicate that landscape evolution arising from permafrost thaw acts as a positive feedback mechanism that increases the energy absorbed at the land surface and produces additional permafrost thaw. The modeling results also demonstrate that flow rates in local groundwater flow systems may be enhanced by the degradation of isolated permafrost bodies.

Fir Decline and Mortality in the Southern Siberian Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

2016-01-01

Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata)) were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (18 deg to 25 deg), convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width (TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies) have a high impact on current TRW (r = 0.60 to 0.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest- steppe) and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

Improving Large-scale Biomass Burning Carbon Consumption and Emissions Estimates in the Former Soviet Union based on Fire Weather

NASA Astrophysics Data System (ADS)

Westberg, D. J.; Soja, A. J.; Tchebakova, N.; Parfenova, E. I.; Kukavskaya, E.; de Groot, B.; McRae, D.; Conard, S. G.; Stackhouse, P. W., Jr.

2012-12-01

Estimating the amount of biomass burned during fire events is challenging, particularly in remote and diverse regions, like those of the Former Soviet Union (FSU). Historically, we have typically assumed 25 tons of carbon per hectare (tC/ha) is emitted, however depending on the ecosystem and severity, biomass burning emissions can range from 2 to 75 tC/ha. Ecosystems in the FSU span from the tundra through the taiga to the forest-steppe, steppe and desserts and include the extensive West Siberian lowlands, permafrost-lain forests and agricultural lands. Excluding this landscape disparity results in inaccurate emissions estimates and incorrect assumptions in the transport of these emissions. In this work, we present emissions based on a hybrid ecosystem map and explicit estimates of fuel that consider the depth of burning based on the Canadian Forest Fire Weather Index System. Specifically, the ecosystem map is a fusion of satellite-based data, a detailed ecosystem map and Alexeyev and Birdsey carbon storage data, which is used to build carbon databases that include the forest overstory and understory, litter, peatlands and soil organic material for the FSU. We provide a range of potential carbon consumption estimates for low- to high-severity fires across the FSU that can be used with fire weather indices to more accurately estimate fire emissions. These data can be incorporated at ecoregion and administrative territory scales and are optimized for use in large-scale Chemical Transport Models. Additionally, paired with future climate scenarios and ecoregion cover, these carbon consumption data can be used to estimate potential emissions.

Effects of parasites and antigenic challenge on metabolic rates and thermoregulation in northern red-backed voles (Myodes rutilus).

PubMed

Novikov, Eugene; Kondratyuk, Ekaterina; Petrovski, Dmitry; Krivopalov, Anton; Moshkin, Mikhail

2015-12-01

Perturbations in host energetics are considered to be an essential pathway for parasite impact on host fitness. However, direct estimations of parasite-induced variations in basal metabolic rates of vertebrate hosts have so far provided contradictory results. The energy requirements of immunity and other vital functions may be compromised in energy-demanding conditions in comparison to comfortable conditions; therefore, in our study performed on the wild red-backed vole, Myodes rutilus, we compared the values of indices that reflect metabolic and thermoregulatory responses to acute cooling in individuals that had been naturally infected by gut helminths or Ixodes persulcatus taiga ticks to individuals with no signs of infestation. To consider the possible effects of an acquired immune response on host energetics, we also injected some of the tested individuals with sheep red blood cells (SRBC). Red-backed voles infected by the nematode Heligmosomum mixtum injected with SRBC showed significantly lower cold-induced maximum oxygen consumption than the saline control. Additionally, individuals infected with H. mixtum showed significantly lower oxygen consumption during the final minute of the 15-min acute cooling period and a significantly greater decline in body temperature than individuals free from helminths. In individuals concurrently infected by H. mixtum and the cestodes Arostrilepis horrida, these indices did not differ from helminth-free individuals. The number of ticks simultaneously parasitizing the voles at the moment of capture correlated positively with their SMR. Our results suggest that even natural parasites produce deleterious effects on host aerobic capacity and thermoregulatory abilities, although the effects of different parasites might not be additive.

A new species of Arctoseius Thor, 1930 (Acari: Ascidae) from taiga regions of the Palaearctic, with a key to Arctoseius species of Fennoscandia, NW Europe.

PubMed

Makarova, Olga L; Huhta, Veikko

2017-05-18

A new mesostigmatid mite species belonging to the genus Arctoseius Thor, 1930, is described based on material from subarctic coniferous forests, Finland, and Altai highlands, Russia. Arctoseius ambiguus sp. nov. is similar to Arctoseius venustulus (Berlese, 1916), but can be distinguished from the latter by its larger size, wider dorsal shield, weakly sclerotized presternal platelets, pronounced differences in the length of opisthonotal setae, and distinct punctation of the anal shield. A key for 15 Arctoseius species recorded in continental North-Western Europe (Fennoscandia) is given. The Fennoscandian fauna of Arctoseius species is rather specialised. It includes four European temperate species and five cryobiontic (arctic, arcto-montane, arcto-boreo-montane) ones.

Extended abstracts for an international conference on the development of the North and problems of recultivation

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

Everett, K.R.

1994-12-31

Ecological problems in many regions on Earth are the result of increasing technological pressure on the environment. These problems concern many of us and cause mankind to unite in order to search for means to protect the environment. Scientists, especially are responsible for the protection of the biosphere. The objective of this conference was to discuss the results of studies on the present condition of the environment in the Far North where the industrial pressure is increasing. The participants of this conference also offered and suggested various necessary measures for the protection of the region and restoration of its disturbedmore » sites. The specific structural characteristics of the environment of the Far North, tundra and northern taiga, cause its fragility and vulnerability to anthropogenic impact. The destruction of the thin, weak layer of soil and vegetation cover changes the thermal balance and thus causes the development of erosion process, which in their turn increase the zone of the direct technogenous destruction. Self restoration processes in this harsh climate usually are slow. The preservation of the ecological integrity in the Far North is essential for the stability of the biosphere of the planet. The specifics of the natural conditions must be taken into account so that man will be able to develop the means of intensive agro-technology that can speed up the process of restoration of the biocenosis in the damaged areas. The extended abstracts of the conference reports that constitute this volume contain both theoretical discussions of problems of recultivation as well as accounts of experimental studies and applied explorations.« less

Biomes computed from simulated climatologies

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

Claussen, M.; Esch, M.

1994-01-01

The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a differencemore » in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting chances in vegetation patterns due to a rapid climate change, the latter simulation to be taken as a prediction of chances in conditions favourable for the existence of certain biomes, not as a reduction of a future distribution of biomes. 15 refs., 8 figs., 2 tabs.« less

The initiation and development of small peat-forming ecosystems adjacent to lakes in the north central Canadian low arctic during the Holocene

NASA Astrophysics Data System (ADS)

Camill, Philip; Umbanhowar, Charles E.; Geiss, Christoph; Edlund, Mark B.; Hobbs, Will O.; Dupont, Allison; Doyle-Capitman, Catherine; Ramos, Matthew

2017-07-01

Small peat-forming ecosystems in arctic landscapes may play a significant role in the regional biogeochemistry of high-latitude systems, yet they are understudied compared to arctic uplands and other major peat-forming regions of the North. We present a new data set of 25 radiocarbon-dated permafrost peat cores sampled around eight low arctic lake sites in northern Manitoba (Canada) to examine the timing of peat initiation and controls on peat accumulation throughout the Holocene. We used macrofossils and charcoal to characterize changes in the plant community and fire, and we explored potential impacts of these local factors, as well as regional climatic change, on rates of C accumulation and C stocks. Peat initiation was variable across and within sites, suggesting the influence of local topography, but 56% of the cores initiated after 3000 B.P. Most cores initiated and remained as drier bog hummock communities, with few vegetation transitions in this landscape. C accumulation was relatively slow and did not appear to be correlated with Holocene-scale climatic variability, but C stocks in this landscape were substantial (mean = 45.4 kg C m-2), potentially accounting for 13.2 Pg C in the Taiga Shield ecozone. To the extent that small peat-forming systems are underrepresented in peatland mapping, soil organic carbon (SOC) stocks may be underestimated in arctic regions. Mean fire severity appeared to be negatively correlated with C accumulation rates. Initiation and accumulation of soil C may respond to both regional and local factors, and substantial lowland soil C stocks have the potential for biogeochemical impacts on adjacent aquatic ecosystems.

Estimates of phytomass and net primary productivity in terrestrial ecosystems of the former Soviet Union identified by classified Global Vegetation Index

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

Gaston, G.G.; Kolchugina, T.P.

1995-12-01

Forty-two regions with similar vegetation and landcover were identified in the former Soviet Union (FSU) by classifying Global Vegetation Index (GVI) images. Image classes were described in terms of vegetation and landcover. Image classes appear to provide more accurate and precise descriptions for most ecosystems when compared to general thematic maps. The area of forest lands were estimated at 1,330 Mha and the actual area of forest ecosystems at 875 Mha. Arable lands were estimated to be 211 Mha. The area of the tundra biome was estimated at 261 Mha. The areas of the forest-tundra/dwarf forest, taiga, mixed-deciduous forest andmore » forest-steppe biomes were estimated t 153, 882, 196, and 144 Mha, respectively. The areas of desert-semidesert biome and arable land with irrigated land and meadows, were estimated at 126 and 237 Mha, respectively. Vegetation and landcover types were associated with the Bazilevich database of phytomass and NPP for vegetation in the FSU. The phytomass in the FSU was estimated at 97.1 Gt C, with 86.8 in forest vegetation, 9.7 in natural non-forest and 0.6 Gt C in arable lands. The NPP was estimated at 8.6 Gt C/yr, with 3.2, 4.8, and 0.6 Gt C/yr of forest, natural non-forest, and arable ecosystems, respectively. The phytomass estimates for forests were greater than previous assessments which considered the age-class distribution of forest stands in the FSU. The NPP of natural ecosystems estimated in this study was 23% greater than previous estimates which used thematic maps to identify ecosystems. 47 refs., 4 figs., 2 tabs.« less

Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America.

PubMed

Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

2014-07-15

Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing.

Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America

PubMed Central

Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

2014-01-01

Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910–1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing. PMID:24982132

Estimating Snow Water Storage in North America Using CLM4, DART, and Snow Radiance Data Assimilation

NASA Technical Reports Server (NTRS)

Kwon, Yonghwan; Yang, Zong-Liang; Zhao, Long; Hoar, Timothy J.; Toure, Ally M.; Rodell, Matthew

2016-01-01

This paper addresses continental-scale snow estimates in North America using a recently developed snow radiance assimilation (RA) system. A series of RA experiments with the ensemble adjustment Kalman filter are conducted by assimilating the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) brightness temperature T(sub B) at 18.7- and 36.5-GHz vertical polarization channels. The overall RA performance in estimating snow depth for North America is improved by simultaneously updating the Community Land Model, version 4 (CLM4), snow/soil states and radiative transfer model (RTM) parameters involved in predicting T(sub B) based on their correlations with the prior T(sub B) (i.e., rule-based RA), although degradations are also observed. The RA system exhibits a more mixed performance for snow cover fraction estimates. Compared to the open-loop run (0.171m RMSE), the overall snow depth estimates are improved by 1.6% (0.168m RMSE) in the rule-based RA whereas the default RA (without a rule) results in a degradation of 3.6% (0.177mRMSE). Significant improvement of the snow depth estimates in the rule-based RA as observed for tundra snow class (11.5%, p < 0.05) and bare soil land-cover type (13.5%, p < 0.05). However, the overall improvement is not significant (p = 0.135) because snow estimates are degraded or marginally improved for other snow classes and land covers, especially the taiga snow class and forest land cover (7.1% and 7.3% degradations, respectively). The current RA system needs to be further refined to enhance snow estimates for various snow types and forested regions.

Assessing Wildfire Effects in North American Boreal Peatlands through Field and Remote Sensing Analysis

NASA Astrophysics Data System (ADS)

Bourgeau-Chavez, L. L.; French, N. H. F.; Endres, S.; Kane, E. S.; Jenkins, L. K.; Hanes, C.; Battaglia, M., Jr.; de Groot, W.

2017-12-01

Wildfire is a natural disturbance factor in high northern latitude (HNL) ecosystems occurring primarily through lightning ignitions. However, there is evidence that frequency of wildfire in both boreal and arctic landscapes is increasing with climate change. Higher temperatures and reduced precipitation is leading to widespread seasonal drying in some HNL landscapes, thereby increasing wildfire frequency and severity. In 2014, Northwest Territories (NWT) Canada had a record breaking year of wildfire, burning over 3.4 million hectares of upland forests, peatlands, and even emergent wetlands. Fire activity occurred across seasons (spring, summer, and fall) in the Taiga Shield and Boreal Plains ecozones. Similar large fire years have occurred in boreal Alaska in 2004 and 2015. Under NASA ABoVE, boreal peatlands of Alberta and NWT Canada are the focus of both field and remote sensing studies to better understand their vulnerability and resiliency to wildfire. Landsat and radar satellite imagery are being used to develop remote sensing algorithms specific to peatlands to map and monitor not only burn severity but also organic soil moisture, peatland type (e.g. bog vs. fen) and biomass form (herbaceous, shrub, forest dominated). Field data analysis of tree recruitment, in situ moisture, burn severity, fuel loading and other biophysical parameters are currently being synthesized from three field seasons. The field and remote sensing data are being integrated with CanFIRE (a carbon emissions and fire effects model) to better understand the wildfire effects to peatlands. The spatial information allows for better quantification of the landscape heterogeneity of peatlands, thus providing new insights to landscape scale changes and allowing improved understanding of the implications of increasing wildfire in HNL ecosystems.

[Developmental instability of the organism as a result of pessimization of environment under anthropogenic transformation of natural landscapes].

PubMed

Shadrina, E G; Vol'pert, Ia L

2014-01-01

The value of fluctuating asymmetry is considered to be an indicator of the developmental instability of the organism. The consequences of activities of the mining industry plants, which are characterized by alienation and transformation of large areas of natural landscapes, are analyzed as an anthropogenic factor. The objects of study were small mammals (northern red-backed (Clethrionomys rutilus) and gray red-backed (Clethrionomys rufocanus) voles, tundra vole (Microtus oeconomus), Laxmann's (Sorex caecutiens) and tundra (S. tundrensis) shrews) and trees (Japanese white birch (Betula platyphylla), Betula divaricate, Betula exilis, Duschekiafruticosa, and common osier (Salix viminalis)). In total, 3500 skulls and approximately 30000 leaves collected in the taiga zone of Yakutia were studied. The index offluctuating asymmetry, as well as population parameters and composition of small mammal communities, were analyzed. The data on the value of the fluctuating asymmetry in the studied species in natural habitats are given. It is shown that, in natural conditions, this parameter can rise with deterioration in living conditions, particularly at the ecological periphery of the range. Anthropogenic transformation of natural landscapes creates an "anthropogenic periphery" and causes changes similar to the adaptive responses at the northern limit of the distribution of species. It was found that, through pollution and disruption of ecosystems, the mining industry affects all levels of organization of the living matter, but the population and cenotic parameters give an unambiguous response only at macroanthropogenic transformations. Increase in the level of fluctuating asymmetry is the most sensitive indicator of anthropogenic impact and it should also be taken into account that disruptions in the developmental stability of an organism reflect the destructive processes occurring in the population and community.

A Distributed Snow Evolution Modeling System (SnowModel)

NASA Astrophysics Data System (ADS)

Liston, G. E.; Elder, K.

2004-12-01

A spatially distributed snow-evolution modeling system (SnowModel) has been specifically designed to be applicable over a wide range of snow landscapes, climates, and conditions. To reach this goal, SnowModel is composed of four sub-models: MicroMet defines the meteorological forcing conditions, EnBal calculates surface energy exchanges, SnowMass simulates snow depth and water-equivalent evolution, and SnowTran-3D accounts for snow redistribution by wind. While other distributed snow models exist, SnowModel is unique in that it includes a well-tested blowing-snow sub-model (SnowTran-3D) for application in windy arctic, alpine, and prairie environments where snowdrifts are common. These environments comprise 68% of the seasonally snow-covered Northern Hemisphere land surface. SnowModel also accounts for snow processes occurring in forested environments (e.g., canopy interception related processes). SnowModel is designed to simulate snow-related physical processes occurring at spatial scales of 5-m and greater, and temporal scales of 1-hour and greater. These include: accumulation from precipitation; wind redistribution and sublimation; loading, unloading, and sublimation within forest canopies; snow-density evolution; and snowpack ripening and melt. To enhance its wide applicability, SnowModel includes the physical calculations required to simulate snow evolution within each of the global snow classes defined by Sturm et al. (1995), e.g., tundra, taiga, alpine, prairie, maritime, and ephemeral snow covers. The three, 25-km by 25-km, Cold Land Processes Experiment (CLPX) mesoscale study areas (MSAs: Fraser, North Park, and Rabbit Ears) are used as SnowModel simulation examples to highlight model strengths, weaknesses, and features in forested, semi-forested, alpine, and shrubland environments.

Biologically Active Organic Matter in Soils of European Russia

NASA Astrophysics Data System (ADS)

Semenov, V. M.; Kogut, B. M.; Zinyakova, N. B.; Masyutenko, N. P.; Malyukova, L. S.; Lebedeva, T. N.; Tulina, A. S.

2018-04-01

Experimental and literature data on the contents and stocks of active organic matter in 200 soil samples from the forest-tundra, southern-taiga, deciduous-forest, forest-steppe, dry-steppe, semidesert, and subtropical zones have been generalized. Natural lands, agrocenoses, treatments of long-term field experiments (bare fallow, unfertilized and fertilized crop rotations, perennial plantations), and different layers of soil profile are presented. Sphagnum peat and humus-peat soil in the tundra and forest-tundra zones are characterized by a very high content of active organic matter (300-600 mg C/100 g). Among the zonal soils, the content of active organic matter increases from the medium (75-150 mg C/100 g) to the high (150-300 mg C/100 g) level when going from soddy-podzolic soil to gray forest and dark-gray forest soils and then to leached chernozem. In the series from typical chernozem to ordinary and southern chernozem and chestnut and brown semidesert soils, a decrease in the content of active organic matter to the low (35-75 mg C/100 g) and very low (<35 mg C/100 g) levels is observed. Acid brown forest soil in the subtropical zone is characterized by a medium supply with active organic matter. Most arable soils are mainly characterized by low or very low contents of active organic matter. In the upper layers of soils, active organic matter makes up 1.2-11.1% of total Corg. The profile distribution of active organic matter in the studied soils coincides with that of Corg: their contents appreciably decrease with depth, except for brown semidesert soil. The stocks of active organic matter vary from 0.4 to 5.4 t/ha in the layer of 0-20 cm and from 1.0 to 12.4/ha in the layer of 0-50 cm of different soil types.

NifH-Harboring Bacterial Community Composition across an Alaskan Permafrost Thaw Gradient

PubMed Central

Penton, C. Ryan; Yang, Caiyun; Wu, Liyou; Wang, Qiong; Zhang, Jin; Liu, Feifei; Qin, Yujia; Deng, Ye; Hemme, Christopher L.; Zheng, Tianling; Schuur, Edward A. G.; Tiedje, James; Zhou, Jizhong

2016-01-01

Since nitrogen (N) is often limiting in permafrost soils, we investigated the N2-fixing genetic potential and the inferred taxa harboring those genes by sequencing nifH gene fragments in samples taken along a permafrost thaw gradient in an Alaskan boreal soil. Samples from minimally, moderately and extensively thawed sites were taken to a depth of 79 cm to encompass zones above and below the depth of the water table. NifH reads were translated with frameshift correction and 112,476 sequences were clustered at 5% amino acid dissimilarity resulting in 1,631 OTUs. Sample depth in relation to water table depth was correlated to differences in the NifH sequence classes with those most closely related to group I nifH-harboring Alpha- and Beta-Proteobacteria in higher abundance above water table depth while those related to group III nifH-harboring Delta Proteobacteria more abundant below. The most dominant below water table depth NifH sequences, comprising 1/3 of the total, were distantly related to Verrucomicrobia-Opitutaceae. Overall, these results suggest that permafrost thaw alters the class-level composition of N2-fixing communities in the thawed soil layers and that this distinction corresponds to the depth of the water table. These nifH data were also compared to nifH sequences obtained from a study at an Alaskan taiga site, and to those of other geographically distant, non-permafrost sites. The two Alaska sites were differentiated largely by changes in relative abundances of the same OTUs, whereas the non-Alaska sites were differentiated by the lack of many Alaskan OTUs, and the presence of unique halophilic, sulfate- and iron-reducing taxa in the Alaska sites. PMID:27933054

The distribution and utility of sea-level indicators in Eurasian sub-Arctic salt marshes (White Sea, Russia).

NASA Astrophysics Data System (ADS)

Nikitina, Daria; Kemp, Andrew; Horton, Benjamin; Van, Christopher; Potapova, Marina; Culver, Stephen; Repkina, Tatyana; Hill, David

2017-04-01

We investigated the utility of foraminifera, diatoms and bulk-sediment geochemistry (δ13C and parameters measured by RockEval pyrolysis) as sea-level indicators in Eurasian sub-Arctic salt marshes. At three salt marshes in Dvina Bay (White Sea, Russia), we collected surface sediment samples along transects sequentially crossing sub-tidal, tidal-flat, salt-marsh and Taiga forest environments. Foraminifera formed bipartite assemblages, where elevations below mean high higher water (MHHW) were dominated by Miliammina spp. and elevations between MHHW and the highest occurrence of foraminifera were dominated by Jadammina macrescens and Balticammina pseudomacrescens. Both assemblages existed on all three transects and we conclude that foraminifera are sea-level indicators in Eurasian sub-Arctic salt marshes. Five, high-diversity groups of diatoms were identified and they displayed geographic variability among the study sites (<15 km apart). RockEval pyrolysis and δ13C measurements recognized two groups (clastic-dominated environments below MHHW and organic-rich environments above MHHW). Since one group included sub-tidal elevations and the other supra-tidal elevations, we conclude that the measured geochemical parameters do not meet the criteria for being stand-alone sea-level indicators. Core JT2012 captured a regressive sediment sequence of clastic, tidal-flat sediment overlain by salt-marsh organic silt and freshwater peat. The salt-marsh sediment accumulated at 2804 ± 52 years BP years before present and preserved foraminifera (J. macrescens and B. pseudomacrescens) with a high degree of analogy to modern assemblages indicating that relative sea level was 2.60 ± 0.47 m above present at this time. Diatoms confirm that marine influence decreased through time, but the lack of analogy between modern and core assemblages limits their utility as sea-level indicators in this setting.

Contemporary dynamics of active layer thickness of Northeastern Eurasia: evidence of climate warming, cooling or cyclicity?

NASA Astrophysics Data System (ADS)

Maslakov, A.; Tregubov, O.; Ruzanov, V.; Fedorov-Davydov, D.; Davydov, S. P.; Shiklomanov, N. I.; Streletskiy, D. A.

2017-12-01

Active layer is an intermediate position between the atmosphere and permafrost. It develops in warm period of the year in cryolithozone. Active layer thickness (ALT), or seasonal thaw depth is sensitive to the changes of the weather and climate; it also defines the intensity of such processes as thermokarst and thermal erosion, which have great impact on Arctic infrastructure. Active layer formation mechanism and natural factors affecting its spatial distribution are well studied on the regional scale, but high local variability of ALT brings uncertainty to the modelled results; it also forms multidirectional trends in interannual variations of ALT. This study presents the results of long-term observations of the seasonal thaw dynamics in Northeastern tip of Eurasia. The data is presented by field measurements, conducted in framework of Circumpolar Active Layer Monitoring (CALM) program and study materials of Dionisiya field permafrost station. The key sites are located in three areas: Kolyma lowland (NE Yakutia), Anadyr lowland (SW Chukotka) and Chukchi peninsula (Eastern Chukotka). They represent natural conditions ranging from typical tundra to northern taiga, developed on continuous permafrost extent. The analysis of interannual fluctuations of ALT and summer air temperatures detected common patterns and trends: the majority of considered monitoring sites demonstrates deepening of thaw depths, which was traced in 1980-1990s, following increasing summer air temperature. This period was followed by relative stabilization of ALT in 2000-2010s. Nevertheless, several sites in Kolyma lowland and in Eastern Chukotka demonstrate persistent ALT increase during 2000-2010, even despite of summer temperatures stabilization. At the same time monitoring sites in Dionisiya permafrost station show shrinking of seasonal thaw in 2005-2015. Presented study shows ambiguity of cryosphere response to climate changes and identifies the need for further studies of interaction between

The history of the beginning of the Russian cosmodrome Plesetsk

NASA Astrophysics Data System (ADS)

Shatalov, D. V.

1997-01-01

There are three main dates in the history of the beginning and foundation of cosmodrome Plesetsk, each of which more or less may be considered as the birthday of cosmodrome. On January 11, 1957 the Soviet Government passed the resolution about the foundation of special military object with secret name "Angara", which later became known as cosmodrome Plesetsk, this secret object had to be situated in Plesetsk region Arhangelsk territory. It was named after the railway station Plesetsk and the town Plesetsk. The first Soviet Combat formation of intercontinental ballistic missiles R-7 of General designer Koroljev had to be located in that place, in thick northern taiga to the south of Arhangelsk. July 15, 1957 was the official birthday of the proving ground. That day colonel Gregorjev assumed his post as the missile unit commander. That was the time of the "cold war" between two superstates. Almost nobody thought about space employment of Plesetsk. First of all it was founded as the missile base for combat patrol of intercontinental ballistic missiles. And by July 15, 1961 four missile complexes for ballistic missile R-7 were on combat patrol. March 17, 1966 was the space birthday of Plesetsk. That day was the first missile launching of the rocket booster Vostok with space vehicle Cosmos 112. Since that time the rocket base Angara has become cosmodrome Plesetsk. It is interesting to know that till that time the USA secret service knew practically nothing about Plesetsk proving ground. The confirmation was the fact that there were two peaks of reconnaissance satellite launching intensity: during the Caribbean crisis in 1962 and after the launching of Cosmos 112 in 1966. In a year after the first space launching the proving ground near Plesetsk has become the main place in the USSR to launch the automatic vehicles.

Comparative analysis of the roles of Ixodes persulcatus and I. trianguliceps ticks in natural foci of ixodid tick-borne borrelioses in the Middle Urals, Russia.

PubMed

Korenberg, Edward I; Kovalevskii, Yurii V; Gorelova, Natalya B; Nefedova, Valentina V

2015-04-01

Long-term studies on natural foci of ixodid tick-borne borrelioses (ITBB) have been performed in Chusovskoi district of Perm region, the Middle Urals, where the vectors of these infections are represented by two ixodid tick species: the taiga tick Ixodes persulcatus and many times less abundant vole tick I. trianguliceps. Over 10 years, more than 6000 half-engorged ticks were collected from small forest mammals using the standard procedure, and 1027 I. persulcatus and 1142 I. trianguliceps ticks, individually or in pools, were used to inoculate BSK-2 medium. As a result, 199 Borrelia isolates were obtained. Among them, 177 isolates were identified, and the rrf(5S)-rrl(23S) intergenic spacer sequence was determined in 57 isolates. The prevalence of Borrelia infection in I. persulcatus larvae and nymphs averaged 31.0 and 53.3%, while that in I. trianguliceps larvae, nymphs, and adult ticks was five to ten times lower: 2.6, 10.2, and 8.1%, respectively. Each of the two tick species was found to carry both ITBB agents circulating in the Middle Ural foci (Borrelia garinii and B. afzelii), but the set of genogroups and genovariants of these spirochetes in I. trianguliceps proved to be far less diverse. According to the available data, this tick, compared to I. persulcatus, is generally less susceptible to Borrelia infection (especially by B. afzelii). Taking into account of its relatively low abundance, it appears that I. trianguliceps cannot seriously influence the course of epizootic process in ITBB foci of the study region, whereas highly abundant I. persulcatus with the high level of Borrelia infection is obviously a key component of these parasitic systems. A similar situation may well be typical for the entire geographic range shared by the two tick species. Copyright © 2015. Published by Elsevier GmbH.

Fire Impact on Phytomass and Carbon Emissions in the Forests of Siberia

NASA Astrophysics Data System (ADS)

Ivanova, Galina A.; Zhila, Sergei V.; Ivanov, Valery A.; Kovaleva, Nataly M.; Kukavskaya, Elena A.; Platonova, Irina A.; Conard, Susan G.

2014-05-01

Siberian boreal forests contribute considerably to the global carbon budget, since they take up vast areas, accumulate large amount of carbon, and are sensitive to climatic changes. Fire is the main forest disturbance factor, covering up to millions of hectares of boreal forests annually, of which the majority is in Siberia. Carbon emissions released from phytomass burning influence atmospheric chemistry and global carbon cycling. Changing climate and land use influence the number and intensity of wildfires, forest state, and productivity, as well as global carbon balance. Fire effects on forest overstory, subcanopy woody layer, and ground vegetation phytomass were estimated on sites in light-conifer forests of the Central Siberia as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). This study focuses on collecting quantitative data and modeling the influence of fires of varying intensity on fire emissions, carbon budget, and ecosystem processes in coniferous stands. Fires have a profound impact on forest-atmospheric carbon exchange and transform forests from carbon sinks to carbon sources lasting long after the time of burning. Our long-term experiments allowed us to identify vegetation succession patterns in taiga Scots pine stands after fires of known behavior. Estimating fire contributions to the carbon budget requires consideration of many factors, including vegetation type and fire type and intensity. Carbon emissions were found to depend on fire intensity and weather. In the first several years after fire, the above-ground phytomass appeared to be strongly controlled by fire intensity. However, the influence of burning intensity on organic matter accumulation was found to decrease with time.

NifH-Harboring Bacterial Community Composition across an Alaskan Permafrost Thaw Gradient

DOE PAGES

Penton, C. Ryan; Yang, Caiyun; Wu, Liyou; ...

2016-11-24

Since nitrogen (N) is often limiting in permafrost soils, we investigated the N 2-fixing genetic potential and the inferred taxa harboring those genes by sequencing nifH gene fragments in samples taken along a permafrost thaw gradient in an Alaskan boreal soil. Samples from minimally, moderately and extensively thawed sites were taken to a depth of 79 cm to encompass zones above and below the depth of the water table. NifH reads were translated with frameshift correction and 112,476 sequences were clustered at 5% amino acid dissimilarity resulting in 1,631 OTUs. Sample depth in relation to water table depth was correlatedmore » to differences in the NifH sequence classes with those most closely related to group I nifH-harboring Alpha- and Beta-Proteobacteria in higher abundance above water table depth while those related to group III nifH-harboring Delta Proteobacteria more abundant below. The most dominant below water table depth NifH sequences, comprising 1/3 of the total, were distantly related to Verrucomicrobia-Opitutaceae. Overall, these results suggest that permafrost thaw alters the class-level composition of N 2-fixing communities in the thawed soil layers and that this distinction corresponds to the depth of the water table. These nifH data were also compared to nifH sequences obtained from a study at an Alaskan taiga site, and to those of other geographically distant, non-permafrost sites. The two Alaska sites were differentiated largely by changes in relative abundances of the same OTUs, whereas the non-Alaska sites were differentiated by the lack of many Alaskan OTUs, and the presence of unique halophilic, sulfate- and iron-reducing taxa in the Alaska sites.« less

Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia

PubMed Central

Wild, Birgit; Schnecker, Jörg; Knoltsch, Anna; Takriti, Mounir; Mooshammer, Maria; Gentsch, Norman; Mikutta, Robert; Alves, Ricardo J Eloy; Gittel, Antje; Lashchinskiy, Nikolay; Richter, Andreas

2015-01-01

Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using 15N pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67°N) to steppe (54°N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest. Key Points We compared soil N dynamics of seven ecosystems along a latitudinal transectShifts in N dynamics suggest a decrease in microbial N limitation with depthWe found no decrease in microbial N limitation from arctic to temperate zones PMID:26693204

Monitoring Seasons Through Global Learning Communities

NASA Astrophysics Data System (ADS)

Sparrow, E. B.; Robin, J. H.; Jeffries, M. O.; Gordon, L. S.; Verbyla, D. L.; Levine, E. R.

2006-12-01

Monitoring Seasons through Global Learning Communities (MSTGLC) is an inquiry- and project-based project that monitors seasons, specifically their interannual variability, in order to increase K-12 students' understanding of the Earth system by providing teacher professional development in Earth system science and inquiry, and engaging K-12 students in Earth system science research relevant to their local communities that connect globally. MSTGLC connects GLOBE students, teachers, and communities, with educators and scientists from three integrated Earth systems science programs: the International Arctic Research Center, and NASA Landsat Data Continuity and Terra Satellite Missions. The project organizes GLOBE schools by biomes into eight Global Learning Communities (GLCs) and students monitor their seasons through regional based field campaigns. The project expands the current GLOBE phenology network by adapting current protocols and making them biome-specific. In addition, ice and mosquito phenology protocols will be developed for Arctic and Tropical regions, respectively. Initially the project will focus on Tundra and Taiga biomes as phenological changes are so pronounced in these regions. However, our long-term goal is to determine similar changes in other biomes (Deciduous Forest, Desert, Grasslands, Rain Forest, Savannah and Shrubland) based upon what we learn from these two biomes. This project will also contribute to critically needed Earth system science data such as in situ ice, mosquito, and vegetation phenology measurements for ground validations of remotely sensed data, which are essential for regional climate change impact assessments. Additionally it will contribute environmental data critical to prevention and management of diseases such as malaria in Asian, African, and other countries. Furthermore, this project will enable students to participate in the International Polar Year (IPY) (2007-2009) through field campaigns conducted by students in

Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes.

PubMed

Tautenhahn, Susanne; Lichstein, Jeremy W; Jung, Martin; Kattge, Jens; Bohlman, Stephanie A; Heilmeier, Hermann; Prokushkin, Anatoly; Kahl, Anja; Wirth, Christian

2016-06-01

Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods

Benthic bioindicators from the lakes of Northern Yakutia (Siberia, Russia) in paleoclimatic research

NASA Astrophysics Data System (ADS)

Tumanov, O. N.; Nazarova, L. B.; Frolova, L. A.; Pestryakova, L. A.

2012-04-01

High latitude regions are particularly affected by global climate change. Aquatic ecosystems are known to respond quickly and sensitively to such changes (Carpenter et al., 1992; Findlay et al. 2001; Smol et al., 2005). This effect is especially dramatic in regions with continental climates such as Northern and Eastern Siberia. In 2008, Russian-German expedition investigated 33 lakes of Kolyma river basin, North-Eastern Yakutia. The region of investigation is located in the mouth of Kolyma river between approximately 68°2' and 69°4' N and between 159°8' and 161°9' E. It's a most north-eastern region of Yakutia, so it's suitable for paleolimnological investigations. The investigated lakes are situated along the 200 km transect crossing 3 vegetation zones: polygonal tundra, forest tundra and northern taiga. The main aims were establishing a calibration dataset for paleoenvironmental reconstructions by using aquatic organisms, investigation of limnological variables and the influence of the environmental conditions on distribution of aquatic organisms in Yakutian lakes. The modern benthic fauna of the lakes is represented by 89 taxa from 14 taxonomic groups. The most abundant group was Mollusca. The most taxonomically diverse group was Chironomidae. A unique for this region species were discovered, such as Cincinna kamchatica, Physa jarochnovitschae, Colymbetes dolabratus, Ilybius wasastjernae, Xestochironomus sp., Agrypnia sp. etc. Cluster analysis of taxonomical composition of the benthic fauna of these lakes showed high dependency to vegetation zones. The highest levels of hydrobiological indexes (Shannon, Evenness, species richness) were registered in forest tundra. CCA analysis showed that the most influential factors in species distribution were climate-dependant factors, such as mean Tair of July, pH and water depth. Data from taxonomical analysis of Chironomidae group were used for establishing a calibration dataset for paleoenvironmental reconstructions.

Do the paleolimnological reconstructions reflect the influence of acid deposition?

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

Smirnov, D.Y.

1996-12-31

The using possibility of paleolimnological analyses was considered with the documentation aim of acid-forming substances distant transfer on territory of Northern Fennoscandia. The Holocene and ancient interglacial lakes pH-and alkalinity trends, reconstructed by means of bottom sediments diatomic analyses, were studied. It has been made evident that the tendency to sharp changes of these data is revealed on final stages of interglacial periods. At that time the high amplitude of climatic changes with low periodicity is resulting in catastrophic changes of landscapes in the frames of water-catchments bodies. During the last millennium the climatic situation in the Northern Fennoscandia wasmore » changing repeatedly (Medieval Warm Epoch, Little Ice Age, the rise in temperature in 20-40`s of XXth century). In the Little Ice Age (XVI-XIX centuries) the decrease of average annual temperature and intensification of winds velocity have caused a rapid retreat of latitudinal and high-altitude forest boundaries, accompanied by sharp reconstruction of tundra-,forest-tundra-and northern taiga landscapes. These processes have accelerated due to the enforcement of economic activity which caused the destruction of vegetation cover (salt-working, and ship-building since the XIXth century, pasture of reindeer herds since the end of XIXth century). Acidifying of ground and surface waters in the current century could be caused by the increased entry of organic acids, as a result of plant residues decomposition. The decomposition process was activated in the end of XIXth - beginning of XXth century in connection with the rise of temperature and increase of precipitation. Thus, the trends in pH and alkalinity changes in this region can not be used as indicators of acid-forming substances atmospheric deposition increase.« less

The Relationship between the Structure of the Tick-Borne Encephalitis Virus Strains and Their Pathogenic Properties

PubMed Central

Belikov, Sergei I.; Kondratov, Ilya G.; Potapova, Ulyana V.; Leonova, Galina N.

2014-01-01

Tick-borne encephalitis virus (TBEV) is transmitted to vertebrates by taiga or forest ticks through bites, inducing disease of variable severity. The reasons underlying these differences in the severity of the disease are unknown. In order to identify genetic factors affecting the pathogenicity of virus strains, we have sequenced and compared the complete genomes of 34 Far-Eastern subtype (FE) TBEV strains isolated from patients with different disease severity (Primorye, the Russian Far East). We analyzed the complete genomes of 11 human pathogenic strains isolated from the brains of dead patients with the encephalitic form of the disease (Efd), 4 strains from the blood of patients with the febrile form of TBE (Ffd), and 19 strains from patients with the subclinical form of TBE (Sfd). On the phylogenetic tree, pathogenic Efd strains formed two clusters containing the prototype strains, Senzhang and Sofjin, respectively. Sfd strains formed a third separate cluster, including the Oshima strain. The strains that caused the febrile form of the disease did not form a separate cluster. In the viral proteins, we found 198 positions with at least one amino acid residue substitution, of which only 17 amino acid residue substitutions were correlated with the variable pathogenicity of these strains in humans and they authentically differed between the groups. We considered the role of each amino acid substitution and assumed that the deletion of 111 amino acids in the capsid protein in combination with the amino acid substitutions R16K and S45F in the NS3 protease may affect the budding process of viral particles. These changes may be the major reason for the diminished pathogenicity of TBEV strains. We recommend Sfd strains for testing as attenuation vaccine candidates. PMID:24740396

NifH-Harboring Bacterial Community Composition across an Alaskan Permafrost Thaw Gradient

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

Penton, C. Ryan; Yang, Caiyun; Wu, Liyou

Since nitrogen (N) is often limiting in permafrost soils, we investigated the N 2-fixing genetic potential and the inferred taxa harboring those genes by sequencing nifH gene fragments in samples taken along a permafrost thaw gradient in an Alaskan boreal soil. Samples from minimally, moderately and extensively thawed sites were taken to a depth of 79 cm to encompass zones above and below the depth of the water table. NifH reads were translated with frameshift correction and 112,476 sequences were clustered at 5% amino acid dissimilarity resulting in 1,631 OTUs. Sample depth in relation to water table depth was correlatedmore » to differences in the NifH sequence classes with those most closely related to group I nifH-harboring Alpha- and Beta-Proteobacteria in higher abundance above water table depth while those related to group III nifH-harboring Delta Proteobacteria more abundant below. The most dominant below water table depth NifH sequences, comprising 1/3 of the total, were distantly related to Verrucomicrobia-Opitutaceae. Overall, these results suggest that permafrost thaw alters the class-level composition of N 2-fixing communities in the thawed soil layers and that this distinction corresponds to the depth of the water table. These nifH data were also compared to nifH sequences obtained from a study at an Alaskan taiga site, and to those of other geographically distant, non-permafrost sites. The two Alaska sites were differentiated largely by changes in relative abundances of the same OTUs, whereas the non-Alaska sites were differentiated by the lack of many Alaskan OTUs, and the presence of unique halophilic, sulfate- and iron-reducing taxa in the Alaska sites.« less

A Worldwide Community of Primary and Secondary Students and Their Teachers Engage in and Contribute to Geoscience Research

NASA Astrophysics Data System (ADS)

Sparrow, E. B.; Kopplin, M. R.; Yule, S.

2009-12-01

The GLOBE (Global learning and Observations to Benefit the Environment) program is among the most successful long-term citizen scientist programs engaging K-12 students, in-service and pre-service teachers, as well as community members in different areas of geoscience investigations: atmosphere/weather, land cover biology, soils, hydrology, and vegetation phenology. What sustains this multi-nation project is the interest and collaboration among scientists, educators, students and the GLOBE Partnerships that are mostly self-supporting and function in the United States and in a hundred other countries. The GLOBE Program Office in the United States continues to offer, an overall coordinating and leadership function, a website, an infrastructure, management and support for web data entry and access, as well as visualizations, and a much used help desk. In Alaska, GLOBE research and activities are maintained through professional development workshops for educators, continued year-long support for teachers and their students (classroom visits, email, mail and newsletters) including program assessments, funded through federal grants to the University of Alaska Fairbanks. The current earth system science Seasons and Biomes project uses GLOBE protocols as well as newly developed ones to fit the needs of the locale, such as ice freeze-up and break-up seasonality protocols for rivers and lakes in tundra, taiga and other northern biomes, and mosquito phenology protocols for tropical and sub-tropical moist broadleaf forests and other biomes in Asia and Africa, invasive plant species for Africa, and modified plant phenology protocols for temperate deciduous forests in Australia. Students contribute data and use archived data as needed when they conduct geoscience research individually, in small groups or as a class and/or collaboratively with others in schools in other parts of the country and the world.

New Perspectives of "old" Data Sources: the Dataset of Long-Term Research Watersheds in the Former Soviet Union for the Task of Hydrological Models Development, Verification and Comparison

NASA Astrophysics Data System (ADS)

Lebedeva, L.; Semenova, O.

2013-12-01

Lack of detailed process-oriented observational data is often claimed as one of the major obstacle for further advance of hydrological process understanding and development of deterministic models that do not rely on calibration. New sources of hydrological information (satellites, radars etc.) have the perspectives for the future but can not completely replace conventional and experimental observations at the moment. Long-term data-rich research catchments remain valuable if not the only source of information for development, verification, regionalization and comparison of different hydrological and environmental models. There existed the set of more than 20 such basins that were operated according to single observational program from the 1930-1950th to 1990th in the former Soviet Union. Research basins, so called water-balance stations, covered all main climatic and landscape zones such as taiga, forest-steppe, steppe, desert, mountains and permafrost regions. Each station conducted broad range of standard, special and experimental hydrometeorological field studies including spatially distributed meteorological observations, soil and snow variable states, measurements of the groundwater levels, hydrochemistry, evapotranspiration, discharges in several, often nested, slope- and small-scale watersheds, etc. The data were accompanied by the descriptions of observational techniques and landscapes allowing linking natural conditions with dominant hydrological processes. Each station is representative for larger area and the results of local studies could be transferred to other basins in similar conditions. Till recently the data existed only in hard copies in Russian language therefore they are not enough explored yet. We are currently digitizing main part of the observational and supportive materials and make it available for any scientific purpose via website http://hydrograph-model.ru/. We propose to hydrological community to use the data for comprehensive

Response of non-added solutes during nutrient addition experiments in streams

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

2015-12-01

Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may

A meso-network of eddy covariance towers across the Northwest Territories to assess high-latitude carbon and water budgets under increasing pressure

NASA Astrophysics Data System (ADS)

Hurkuck, M.; Marsh, P.; Quinton, W. L.; Humphreys, E.; Lafleur, P.; Helbig, M.; Hould Gosselin, G.; Sonnentag, O.

2017-12-01

Given their large areal coverage, high carbon densities, unique land surface properties, and disturbance regimes, Canada's diverse high-latitude ecosystems across its multiple Arctic, subarctic and boreal ecozones are integral components of the global and regional climate systems. In northwestern Canada, large portions of these ecozones contain permafrost, i.e., perennially cryotic ground. Here, we describe efforts towards a meso-network of nine eddy covariance towers to measure carbon, water and energy fluxes across the Northwest Territories to shed light on high-latitude carbon and water budgets and their rapidly changing biotic and abiotic controls in response to increasing natural and anthropogenic pressures. Distributed across six research sites (Trail Valley Creek, 68.7°N, 133.3°W; Havikpak Creek, 68.3°N, 133.3°W; Daring Lake, 64.8°N, 111.5°W; Smith Creek, 63.1°N, 123.2°W; Scotty Creek, 63.1°N, 123.2°W; Yellowknife, 62.5°N, 114.4°W), the meso-network spans the central portion of the extended ABoVE Study Domain, covering two ecozones (Taiga Plains, Southern Arctic) with differing permafrost regimes (sporadic, discontinuous, continuous), climatic settings (coastal, interior), and seven high-latitude ecosystem types: forested permafrost peat plateau, permafrost-free collapse-scar bog, subarctic woodland, mixed and dwarf-shrub tundra, and sedge fen. With our contribution, we report on the current status of the meso-network development and present results from various synthesis activities examining the role of climatic setting and resulting tundra carbon and water budgets, quantifying the impact of permafrost thaw and associated wetland expansion on boreal forest carbon and water budgets, and determining the relative importance of treeline advance compared to shrub proliferation on tundra carbon and water budgets.

Water and solute mass balance of five small, relatively undisturbed watersheds in the U.S.

USGS Publications Warehouse

Peters, N.E.; Shanley, J.B.; Aulenbach, Brent T.; Webb, R.M.; Campbell, D.H.; Hunt, R.; Larsen, M.C.; Stallard, R.F.; Troester, J.; Walker, J.F.

2006-01-01

Geochemical mass balances were computed for water years 1992-1997 (October 1991 through September 1997) for the five watersheds of the U.S. Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) Program to determine the primary regional controls on yields of the major dissolved inorganic solutes. The sites, which vary markedly with respect to climate, geology, physiography, and ecology, are: Allequash Creek, Wisconsin (low-relief, humid continental forest); Andrews Creek, Colorado (cold alpine, taiga/tundra, and subalpine boreal forest); Ri??o Icacos, Puerto Rico (lower montane, wet tropical forest); Panola Mountain, Georgia (humid subtropical piedmont forest); and Sleepers River, Vermont (humid northern hardwood forest). Streamwater output fluxes were determined by constructing empirical multivariate concentration models including discharge and seasonal components. Input fluxes were computed from weekly wet-only or bulk precipitation sampling. Despite uncertainties in input fluxes arising from poorly defined elevation gradients, lack of dry-deposition and occult-deposition measurements, and uncertain sea-salt contributions, the following was concluded: (1) for solutes derived primarily from rock weathering (Ca, Mg, Na, K, and H4SiO4), net fluxes (outputs in streamflow minus inputs in deposition) varied by two orders of magnitude, which is attributed to a large gradient in rock weathering rates controlled by climate and geologic parent material; (2) the net flux of atmospherically derived solutes (NH4, NO3, SO4, and Cl) was similar among sites, with SO4 being the most variable and NH4 and NO3 generally retained (except for NO 3 at Andrews); and (3) relations among monthly solute fluxes and differences among solute concentration model parameters yielded additional insights into comparative biogeochemical processes at the sites. ?? 2005 Elsevier B.V. All rights reserved.

Soil-geographical and ecological tour in West-Russia: 20 years anniversary

NASA Astrophysics Data System (ADS)

Kuzyakov, Yakov

2013-04-01

Soil-geographical and agro-ecological tour in Russia celebrated in this summer its 20 years anniversary! More than 800 students, PhD students and researcher from Germany, Switzerland, Austria, Sweden and France participated at the tour since 1993. The majority of the participants were students studying soil science, geoecology, geography, agriculture and ecology. The tour is based on a classical Russian zonal approach: a cross-section of climatic zones starting from south taiga, through deciduous forest, forest steppe, steppe, dry steppe, to semi dessert and transition to the desert zone. In each zone the specifics of climate, vegetation, nutrient cycling, and of course soil genesis as well as soil use by forestry and agriculture are described. Half of the soil group units of WRB classification (2006) are presented on about 35 soil profile pits and are described with focus on pedogenic processes and soil forming factors. The following soil groups are described in details by horizons according to WRB soil classification (2006): Arenosols, Podzols, Albeluvisols Histosols, Gleysols, Luvisols, Phaeozems, Chernozems, Kastanozems, Calcisols, Vertisols, Leptosols, Fluvisols, Solonetzes, Solonchaks. In addition to natural conditions, large-scale experiments designing agricultural landscapes (stone steppe), biosphere reserves and conservation areas (Tula-Schneisen, Divnogor'je, Baskunchak), as well as collective agricultural farms (previously kolkhoz) are visited to evaluate the anthropogenic effects on ecosystems and especially on soils. The 2.5 weeks bus journey through many villages and small towns, visits of museums and historical monuments, introduction in the settlement development of different regions provide a broad presentation of Russian history, traditions, life style, and contemporary state. So, combination of very diverse educational part focused on soil and environmental conditions with anthropogenic impacts and local history as well as recent socioeconomic

Climate impact on the tree growth, vigor and productivity in Siberia

NASA Astrophysics Data System (ADS)

Kharuk, V.; Im, S.; Petrov, I.; Dvinskaya, M.

2017-12-01

Changing climate has an impact on the Siberian taiga forests. We analyzed GPP and NPP trends, growth index, and stands mortality within the Central Siberia (48°- 75°N/80°-115°E). Considered forests included larch-dominant (Larix sibirica, L. dahurica) and "dark needle conifer" (DNC: Abies sibirica, Pinus sibirica, Picea obovata) stands. GPP and NPP trends calculated based on the Terra/MODIS products. Growth index calculations based on dendrochronology data. Water stress analysis based on the gravimetric and microwave satellite data and MERRA-2 database. Analyzed variables included precipitation, air temperature, VPD, drought index SPEI, and root zone wetness. We found positive GPP trends within majority (>90%) of larch-dominant and DNC ranges, whereas NPP trends are positive on the <40% territory. Negative NPP trends correlated with growth index within key-sites. Siberian pine and fir growth index increase since late 1970th, turning to depression since late 1980th. Within permafrost zone larch growth correlated with sum of positive (t>+10C°) temperatures and vegetation period length. During recent years larch experience water stress in the beginning of vegetation period. Tree decline and mortality observed within DNC stands, and that phenomenon regularly coincided with zones of negative NPP trends. Mortality correlated with VPD, SPEI, and root zone moisture content. Bark beetles (including aggressive species Polygraphus proximus, similar to Dendroctonus ponderosae in American forests) attacked water-stressed trees. Geographically, mortality began on the margins of the DNC range (e.g., within the forest-steppe ecotone) and on terrain features with maximal water stress risk (narrow-shaped hilltops, convex steep south facing slopes, shallow well-drained soils). Currently, Siberian pine and fir decline observed within southern range of these species. In addition, air temperature and aridity increase promotes Siberian silkmoth (Dendrolimus sibiricus) outbreak that

Carbon, nitrogen, and phosphorus transport by world rivers

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

Meybeck, M.

1982-04-01

The various forms (dissolved and particulate, organic and inorganic) of carbon, nitrogen, and phosphorus in world rivers are reviewed from literature data. Natural levels are based mainly on major rivers for the subarctic and tropical zones which are still unpolluted and on smaller streams for the temperate zone. Atmospheric fallout is also reviewed. Natural contents of dissolved organic carbon (DOC) are mainly dependent on environmental conditions: DOC varies from 1 mg 1/sup -1/ in the mountainous alpine environments to 20 mg 1/sup -1/ in some taiga rivers. The world DOC average is 5.75 mg l/sup -1/. Nitrogen forms include dissolvedmore » organic nitrogen (DON), dissolved inorganic nitrogen (DIN = N - NH/sub 4//sup +/ + N - NO/sub 3//sup -/ + N - NO/sub 2//sup -/), and particulate organic nitrogen (PON). Natural levels are very low: DIN = 120 ..mu..g 1/sup -1/ of which only 15 percent is present as ammonia, and 1 percent as nitrite. Phosphorus is naturally present in very low amounts: around 10 ..mu..g 1/sup -1/ for P-PO/sub 4//sup 3/ and 25 ..mu..g 1/sup -1/ for total dissolved phosphorus (TDP which includes the organic form). The average nutrient content of rains has been estimated with a set of unpolluted stations: P - PO/sub 4/ = 5 ..mu..g 1/sup -1/, TDP = 10, N - NO/sub 2/ = 5, N - NH/sub 4/ = 225, DON = 225, and N - NO/sub 3/ = 175 ..mu..g 1/sup -1/. TOC levels are probably around several mg 1/sup -1/. These contents are very similar to those found in unpolluted rivers. Man's influence on surface waters has now greatly increased natural nutrient levels. Total dissolved P and N have globally increased by a factor of two and locally (Western Europe, North America) by factors of 10 to 50. These increases were found to be directly proportional to the watershed population and to its energy consumption.« less

Long-term measurements (2010-2014) of carbonaceous aerosol and carbon monoxide at the Zotino Tall Tower Observatory (ZOTTO) in central Siberia

NASA Astrophysics Data System (ADS)

Mikhailov, Eugene F.; Mironova, Svetlana; Mironov, Gregory; Vlasenko, Sergey; Panov, Alexey; Chi, Xuguang; Walter, David; Carbone, Samara; Artaxo, Paulo; Heimann, Martin; Lavric, Jost; Pöschl, Ulrich; Andreae, Meinrat O.

2017-12-01

We present long-term (5-year) measurements of particulate matter with an upper diameter limit of ˜ 10 µm (PM10), elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) in aerosol filter samples collected at the Zotino Tall Tower Observatory in the middle-taiga subzone (Siberia). The data are complemented with carbon monoxide (CO) measurements. Air mass back trajectory analysis and satellite image analysis were used to characterise potential source regions and the transport pathway of haze plumes. Polluted and background periods were selected using a non-parametric statistical approach and analysed separately. In addition, near-pristine air masses were selected based on their EC concentrations being below the detection limit of our thermal-optical instrument. Over the entire sampling campaign, 75 and 48 % of air masses in winter and in summer, respectively, and 42 % in spring and fall are classified as polluted. The observed background concentrations of CO and EC showed a sine-like behaviour with a period of 365 ± 4 days, mostly due to different degrees of dilution and the removal of polluted air masses arriving at the Zotino Tall Tower Observatory (ZOTTO) from remote sources. Our analysis of the near-pristine conditions shows that the longest periods with clean air masses were observed in summer, with a frequency of 17 %, while in wintertime only 1 % can be classified as a clean. Against a background of low concentrations of CO, EC, and OC in the near-pristine summertime, it was possible to identify pollution plumes that most likely came from crude-oil production sites located in the oil-rich regions of Western Siberia. Overall, our analysis indicates that most of the time the Siberian region is impacted by atmospheric pollution arising from biomass burning and anthropogenic emissions. A relatively clean atmosphere can be observed mainly in summer, when polluted species are removed by precipitation and the aerosol burden returns to

Soil carbon sequestration due to post-Soviet cropland abandonment: estimates from a large-scale soil organic carbon field inventory.

PubMed

Wertebach, Tim-Martin; Hölzel, Norbert; Kämpf, Immo; Yurtaev, Andrey; Tupitsin, Sergey; Kiehl, Kathrin; Kamp, Johannes; Kleinebecker, Till

2017-09-01

The break-up of the Soviet Union in 1991 triggered cropland abandonment on a continental scale, which in turn led to carbon accumulation on abandoned land across Eurasia. Previous studies have estimated carbon accumulation rates across Russia based on large-scale modelling. Studies that assess carbon sequestration on abandoned land based on robust field sampling are rare. We investigated soil organic carbon (SOC) stocks using a randomized sampling design along a climatic gradient from forest steppe to Sub-Taiga in Western Siberia (Tyumen Province). In total, SOC contents were sampled on 470 plots across different soil and land-use types. The effect of land use on changes in SOC stock was evaluated, and carbon sequestration rates were calculated for different age stages of abandoned cropland. While land-use type had an effect on carbon accumulation in the topsoil (0-5 cm), no independent land-use effects were found for deeper SOC stocks. Topsoil carbon stocks of grasslands and forests were significantly higher than those of soils managed for crops and under abandoned cropland. SOC increased significantly with time since abandonment. The average carbon sequestration rate for soils of abandoned cropland was 0.66 Mg C ha -1  yr -1 (1-20 years old, 0-5 cm soil depth), which is at the lower end of published estimates for Russia and Siberia. There was a tendency towards SOC saturation on abandoned land as sequestration rates were much higher for recently abandoned (1-10 years old, 1.04 Mg C ha -1  yr -1 ) compared to earlier abandoned crop fields (11-20 years old, 0.26 Mg C ha -1  yr -1 ). Our study confirms the global significance of abandoned cropland in Russia for carbon sequestration. Our findings also suggest that robust regional surveys based on a large number of samples advance model-based continent-wide SOC prediction. © 2017 John Wiley & Sons Ltd.

Present Permafrost Thaw in Central Yakutia, North-East Siberia: Surficial Geology and Hydrology Evidence

NASA Astrophysics Data System (ADS)

Czerniawska, Jolanta; Chlachula, Jiri

2017-04-01

Current climate change in the high-latitudes of Eurasia is a generally accepted phenomenon characterized by increased annual temperature values and marked weather anomalies observed in the sub-polar and polar regions. In the northern and NE Siberia, this trend of the MAT rise, documented particularly over the last three decades, is believed to account for the territorial lowland as well as insular mountain frozen ground thaw that in turn has triggered ecosystem feedbacks on the local as well as regional scales. In the northern regions of Yakutia, this is principally witnessed by accelerated near-surface dynamics of seasonally activated de-freezing grounds and inter-linked geomorphic and hydrological actions affecting large-scale tundra landscape settings. In the southern and central taiga-forest areas with perennial alpine and continuous permafrost conditions, respectively, an increased depth of the seasonally melted top-soil layers has become evident accompanied by thermokarst lake expansion and ground surface collapsing. Some cryogenic depressions generated from small gullies over the past decades eloquently demonstrate the intensity and scales of the current permafrost degradation in the Siberian North. The fluvial discharge is most dynamic in late spring to mid-summer because of the cumulative effect of snow-melting because of a high solar radiation and short intervals of torrential rains. Yet, the climate-change-dependent and most active geomorphic agent is the accelerated permafrost thaw seen in landslides and tundra-forest cover decay due to a higher water table. Numerous preserved biotic fossiliferous records Pleistocene and early Holocene in age are being exposed in this process providing unique palaeoecology evidence at particular sites. These climate-generated processes have mostly highly negative effects to the natural habitats (migratory animal routes and riverine biota due to an earlier ice-melting) as well as the local settlement communities

Biomes of western North America at 18,000, 6000 and 0 14C yr BP reconstructed from pollen and packrat midden data

USGS Publications Warehouse

Thompson, R.S.; Anderson, K.H.

2000-01-01

A new compilation of pollen and packrat midden data from western North America provides a refined reconstruction of the composition and distribution of biomes in western North America for today and for 6000 and 18,000 radiocarbon years before present (14C yr BP). Modern biomes in western North America are adequately portrayed by pollen assemblages from lakes and bogs. Forest biomes in western North America share many taxa in their pollen spectra and it can be difficult to discriminate among these biomes. Plant macrofossils from packrat middens provide reliable identification of modern biomes from arid and semiarid regions, and this may also be true in similar environments in other parts of the world. However, a weighting factor for trees and shrubs must be used to reliably reconstruct modern biomes from plant macrofossils. A new biome, open conifer woodland, which includes eurythermic conifers and steppe plants, was defined to categorize much of the current and past vegetation of the semiarid interior of western North America. At 6000 14C yr BP, the forest biomes of the coastal Pacific North-west and the desert biomes of the South-west were in near-modern positions. Biomes in the interior Pacific North-west differed from those of today in that taiga prevailed in modern cool/cold mixed forests. Steppe was present in areas occupied today by open conifer woodland in the northern Great Basin, while in the central and southern Rocky Mountains forests grew where steppe grows today. During the mid-Holocene, cool conifer forests were expanded in the Rocky Mountains (relative to today) but contracted in the Sierra Nevada. These differences from the forests of today imply different climatic histories in these two regions between 6000 14C yr BP and today. At 18,000 14C yr BP, deserts were absent from the South-west and the coverage of open conifer woodland was greatly expanded relative to today. Steppe and tundra were present in much of the region now covered by forests in

Vegetation and climate variability during the Last Interglacial evidenced in the pollen record from Lake Baikal

NASA Astrophysics Data System (ADS)

Granoszewski, W.; Demske, D.; Nita, M.; Heumann, G.; Andreev, A. A.

2005-04-01

A pollen record from the core sediments collected in the northern part of Lake Baikal represents the latest stage of the Taz (Saale) Glaciation, Kazantsevo (Eemian) Interglacial (namely the Last Interglacial), and the earliest stage of the Zyryanka (Weichselian) Glaciation. According to the palaeomagnetic-based age model applied to the core, the Last Interglacial in the Lake Baikal record lasted about 10.6 ky from 128 to 117.4 ky BP, being more or less synchronous with the Marine Isotope Stage 5e. The reconstructed changes in the south Siberian vegetation and climate are summarised as follows: a major spread of shrub alder ( Alnus fruticosa) and shrub birches ( Betula sect. Nanae/ Fruticosae) in the study area was a characteristic feature during the late glacial phase of the Taz Glaciation. Boreal trees e.g. spruce ( Picea obovata) and birch ( Betula sect. Albae) started to play an important role in the regional vegetation with the onset of the interglacial conditions. Optimal conditions for Abies sibirica- P. obovata taiga development occurred ca. 126.3 ky BP. The maximum spread of birch forest-steppe communities took place at the low altitudes ca. 126.5-125.5 ky BP and Pinus sylvestris started to form forests in the northern Baikal area after ca. 124.4 ky BP. Re-expansion of the steppe communities, as well as shrubby alder and willow communities and the disappearance of forest vegetation occurred at about 117.4 ky BP, suggesting the end of the interglacial succession. The changes in the pollen assemblages recorded in the sediments from northern Baikal point to a certain instability of the interglacial climate. Three phases of climate deterioration have been distinguished: 126-125.5, 121.5-120, and 119.5-119 ky BP. The penultimate cooling signal may be correlated with the cool oscillation recorded in European pollen records. However, such far distant correlation requires more careful investigation.

Biome changes in Asia since the mid-Holocene - an analysis of different transient Earth system model simulations

NASA Astrophysics Data System (ADS)

Dallmeyer, Anne; Claussen, Martin; Ni, Jian; Cao, Xianyong; Wang, Yongbo; Fischer, Nils; Pfeiffer, Madlene; Jin, Liya; Khon, Vyacheslav; Wagner, Sebastian; Haberkorn, Kerstin; Herzschuh, Ulrike

2017-02-01

The large variety of atmospheric circulation systems affecting the eastern Asian climate is reflected by the complex Asian vegetation distribution. Particularly in the transition zones of these circulation systems, vegetation is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate-vegetation relationship is lacking. To assess the Holocene vegetation change and to obtain an ensemble of potential mid-Holocene biome distributions for eastern Asia, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient Holocene climate simulations performed in coupled atmosphere-ocean(-vegetation) models. The simulated biome changes are compared with pollen-based biome records for different key regions.In all simulations, substantial biome shifts during the last 6000 years are confined to the high northern latitudes and the monsoon-westerly wind transition zone, but the temporal evolution and amplitude of change strongly depend on the climate forcing. Large parts of the southern tundra are replaced by taiga during the mid-Holocene due to a warmer growing season and the boreal treeline in northern Asia is shifted northward by approx. 4° in the ensemble mean, ranging from 1.5 to 6° in the individual simulations, respectively. This simulated treeline shift is in agreement with pollen-based reconstructions from northern Siberia. The desert fraction in the transition zone is reduced by 21 % during the mid-Holocene compared to pre-industrial due to enhanced precipitation. The desert-steppe margin is shifted westward by 5° (1-9° in the individual simulations). The forest biomes are expanded north-westward by 2°, ranging from 0 to 4° in the single simulations. These results corroborate pollen-based reconstructions indicating an extended forest area in north-central China during the mid-Holocene. According to the model, the forest-to-non-forest and steppe

Multidecadal Rates of Disturbance- and Climate Change-Induced Land Cover Change in Arctic and Boreal Ecosystems over Western Canada and Alaska Inferred from Dense Landsat Time Series

NASA Astrophysics Data System (ADS)

Wang, J.; Sulla-menashe, D. J.; Woodcock, C. E.; Sonnentag, O.; Friedl, M. A.

2017-12-01

predictions. In this paper, we present initial results from this effort, including sub-regional analyses focused on several key areas, such as the Taiga Plains and the Southern Arctic ecozones, to calibrate our random forest models and assess results.

Pan-Eurasian experiment (PEEX) establishing a process towards high level Pan-Eurasian atmosphere-ecosystem observation networks

NASA Astrophysics Data System (ADS)

Lappalainen, Hanna K.; Petäjä, Tuukka; Zaytzeva, Nina; Viisanen, Yrjö; Kotlyakov, Vladimir; Kasimov, Nikolay; Bondur, Valery; Matvienko, Gennady; Zilitinkevich, Sergej; Kulmala, Markku

2014-05-01

Pan-Eurasian Experiment (PEEX) is a new multidisciplinary research approach aiming at resolving the major uncertainties in the Earth system science and global sustainability questions in the Arctic and boreal Pan-Eurasian regions (Kulmala et al. 2011). The main goal of PEEX Research agenda is to contribute to solving the scientific questions that are specifically important for the Pan-Eurasian region in the coming years, in particular the global climate change and its consequences to nature and human society. Pan Eurasian region represents one the Earth most extensive areas of boreal forest (taiga) and the largest natural wetlands, thus being a significant source area of trace gas emissions, biogenic aerosol particles, and source and sink area for the greenhouse gas (GHG) exchange in a global scale (Guenther et al. 1995, Timkovsky et al. 2010, Tunved et al. 2006, Glagolev et al. 2010). One of the first activities of the PEEX initiative is to establish a process towards high level Pan-Eurasian Observation Networks. Siberian region is currently lacking a coordinated, coherent ground based atmosphere-ecosystem measurement network, which would be crucial component for observing and predicting the effects of climate change in the Northern Pan- Eurasian region The vision of the Pan-Eurasion network will be based on a hierarchical SMEAR-type (Stations Measuring Atmosphere-Ecosystem Interactions) integrated land-atmosphere observation system (Hari et al. 2009). A suite of stations have been selected for the Preliminary Phase of PEEX Observation network. These Preliminary Phase stations includes the SMEAR-type stations in Finland (SMEAR-I-II-II-IV stations), in Estonia (SMEAR-Järviselja) and in China (SMEAR-Nanjing) and selected stations in Russia and ecosystem station network in China. PEEX observation network will fill in the current observational gap in the Siberian region and bring the Siberian observation setup into international context with the with standardized or

Annual soil CO_{2} production in Moscow Botanical Garden (Russia).

NASA Astrophysics Data System (ADS)

Udovenko, Maria; Goncharova, Olga; Matyshak, Georgy

2017-04-01

Soil respiration is an essential component of the carbon cycle, determining 25-40 % of carbon dioxide in the atmosphere. Urban soils are subject to significant anthropogenic influences. Anthropogenic impact affects both the plants and the soil microbiota. So, soil CO2 efflux and soil profile CO2 concentration probably differ in urban and natural soils. Influence of abiotic factors on soil carbon dioxide production is explored insufficiently. The research of their impact on soil carbon dioxide production is necessary to predict soil response to anthropogenic climate change. The aim of this study was estimation of annual soil CO2 production and the impact of climatic factors on it. The research took place in Moscow State University Botanical Garden Arboretum (southern taiga). Investigations were carried out at two sites: the areas planted with Picea obovata and Carpinus betulus. The study was conducted with 1-2 weeks intervals between November 2014 and December 2015. Emission measurement were carried out by closed chamber technique, profile concentration were measured by soil air sampling tubes method. Annual carbon dioxide soil surface efflux of soil planted with Picea obovata was 1370 gCO2/(m2 * year), soil planted with Carpinus betulus - 1590 gCO2/(m2 * year). Soil CO2 concentration increased with depth in average of 3300 to 12000 ppm (at 80 cm depth). Maximum concentration values are confined to the end of vegetation period (high biological activity) and to beginning of spring (spring ice cover of soil prevents CO2 emission). Soil CO2 efflux depends on soil temperature at 10 cm depth (R = 0.89; p <0.05), in a less degree it correlate with soil surface temperature and with soil temperature at 20 cm depth (r=0.88; p<0.05). Soil moisture has a little effect on CO2 efflux in the annual cycle (r=-0.16; p<0.05). However in vegetation period efflux of carbon dioxide largely depends on soil moisture, due to the fact, that soil moisture is limiting factor for soil

Contribution of black spruce (Picea mariana) transpiration to growing season evapotranspiration in a subarctic discontinuous permafrost peatland complex

NASA Astrophysics Data System (ADS)

Helbig, M.; Warren, R. K.; Pappas, C.; Sonnentag, O.; Berg, A. A.; Chasmer, L.; Baltzer, J. L.; Quinton, W. L.; Patankar, R.

2016-12-01

Partitioning the components of evapotranspiration (ET), evaporation and transpiration, has been increasingly important for the better understanding and modeling of carbon, water, and energy dynamics, and for reliable water resources quantification and management. However, disentangling its individual processes remains highly uncertain. Here, we quantify the contribution of black spruce transpiration, the dominant overstory, to ET of a boreal forest-wetland landscape in the southern Taiga Plains. In these ecosystems, thawing permafrost induces rapid landscape change, whereby permafrost-supported forested plateaus are transformed into bogs or fens (wetlands), resulting in tree mortality. Using historical and projected rates of forest-wetland changes, we assess how the contribution of black spruce transpiration to landscape ET might be altered with continued permafrost loss, and quantify the resulting water balance changes. We use two nested eddy covariance flux towers and a footprint model to quantify ET over the entire landscape. Sap flux density of black spruce is measured using the heat ratio method during the 2013 (n=22) and 2014 (n=3) growing seasons, and is used to estimate tree-level transpiration. Allometric relations between tree height, diameter at breast height and sapwood area are derived to upscale tree-level transpiration to overstory transpiration within the eddy covariance footprint. Black spruce transpiration accounts for <10% of total landscape ET. The largest daily contribution of overstory transpiration to landscape ET is observed shortly after the landscape becomes snow-free, continually decreasing throughout the progression of the growing season. Total transpiration is notably lower in 2014 (2.34 mm) than 2013 (2.83 mm) over the same 40-day period, corresponding to 3% of cumulative landscape ET in both years. This difference is likely due to the antecedent moisture conditions, where the 2014 growing season was proceeded by lower than average

Total Storage and Landscape Partitioning of Soil Organic Carbon and Phytomass Carbon in Siberia

NASA Astrophysics Data System (ADS)

Siewert, M. B.; Hanisch, J.; Weiss, N.; Kuhry, P.; Hugelius, G.

2014-12-01

We present results of detailed partitioning of soil organic carbon (SOC) and phytomass carbon (PC) from two study sites in Siberia. The study sites in the Tundra (Kytalyk) and the Taiga (Spasskaya Pad) reflect two contrasting environments in the continuous permafrost zone. In total 57 individual field sites (24 and 33 per study site respectively) have have been sampled for SOC and PC along transects cutting across different land covers. In Kytalyk the sampling depth for the soil pedons was 1 m depth. In Spasskaya Pad where the active layer was significantly deeper, we aimed for 2 m depth or tried to include at least the top of the permafrost. Here the average depth of soil profiles was 152 cm. PC was sampled from 1x1 m ground coverage plots. In Spasskaya Pad tree phytomass was also estimated on a 5x5 m plot. The SOC storage was calculated separately for the intervals 0-30 cm, 30-100 cm and 100-200 cm (the latter only for Spasskaya Pad), as well as for organic layer vs. mineral soil, active layer vs. permafrost and for cryoturbated soil horizons. Landscape partitioning was performed by thematic up-scaling using a vegetation based land cover classification of very high resolution (2x2 m) satellite imagery. Non-Metric Multidimensional Scaling (NMDS) was used to explore the relationship of SOC with PC and different soil and permafrost related variables. The results show that the different land cover classes can be considered distinct storages of SOC, but that PC is not significantly related to total SOC storage. At both study sites the 30-100 cm SOC storage is more important for the total SOC storage than the 0-30 cm interval, and large portions of the total SOC are stored in the permafrost. The largest contribution comes from wetland pedons, but highly cryoturbated individual non-wetland pedons can match these. In Kytalyk the landscape partitioning of SOC mostly follows large scale geomorphological features, while in Spasskaya pad forest type also has a large

Traits of Heracleum sosnowskyi Plants in Monostand on Invaded Area

PubMed Central

2015-01-01

The ability of giant hogweeds to form monodominant communities and even pure monostands in invaded areas has been well documented. Understanding of the mechanisms leading to monostand formation can aid in determining the limitations of existing community ecology models and establishing an effective management plan for invasive species elimination. The aim of this observational study was to investigate traits of Heracleum sosnowskyi plants (demography, canopy structure, morphology and physiology) of the plants in a pure stand in an invaded area useful for understanding potential monostand formation mechanisms. All measurements were performed in one typical Heracleum sosnowskyi monostand located in an abandoned agriculture field located in Syktyvkar city suburb (North-east Russia). This monostand consisted of five main plant growth stages: seed, seedling, juvenile, vegetative adult, and generative adult. Plants of all stages began to grow simultaneously shortly after the snowmelt, at the same time as spring ephemeral plant species grew. The density of generative plants did not change during the vegetation period, but the density of the other plant stages rapidly decreased after the formation of a tall (up to 2–2.5 m) and dense (Leaf area index up to 6.5) canopy. The canopy captured approximately 97% of the light. H. sosnowskyi showed high (several orders of magnitude higher than average taiga zone grasses) photosynthetic water use efficiency (6–7 μM CO2/μM H2O). Formation of H. sosnowskyi monostands occurs primarily in disturbed areas with relatively rich and well-moistened soils. Early commencement of growth, rapid formation of a dense canopy, high efficiency of light and water use during photosynthesis, ability of young plants to survive in low light conditions, rapid recovery of above-ground plant parts after damage, and the high density of the soil seed bank are the most important traits of H. sosnowskyi plants for monostand formation in invaded areas. PMID

Peatland classification of West Siberia based on Landsat imagery

NASA Astrophysics Data System (ADS)

Terentieva, I.; Glagolev, M.; Lapshina, E.; Maksyutov, S. S.

2014-12-01

Increasing interest in peatlands for prediction of environmental changes requires an understanding of its geographical distribution. West Siberia Plain is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. West Siberian taiga mires are important globally, accounting for about 12.5% of the global wetland area. A number of peatland maps of the West Siberia was developed in 1970s, but their accuracy is limited. Here we report the effort in mapping West Siberian peatlands using 30 m resolution Landsat imagery. As a first step, peatland classification scheme oriented on environmental parameter upscaling was developed. The overall workflow involves data pre-processing, training data collection, image classification on a scene-by-scene basis, regrouping of the derived classes into final peatland types and accuracy assessment. To avoid misclassification peatlands were distinguished from other landscapes using threshold method: for each scene, Green-Red Vegetation Indices was used for peatland masking and 5th channel was used for masking water bodies. Peatland image masks were made in Quantum GIS, filtered in MATLAB and then classified in Multispec (Purdue Research Foundation) using maximum likelihood algorithm of supervised classification method. Training sample selection was mostly based on spectral signatures due to limited ancillary and high-resolution image data. As an additional source of information, we applied our field knowledge resulting from more than 10 years of fieldwork in West Siberia summarized in an extensive dataset of botanical relevés, field photos, pH and electrical conductivity data from 40 test sites. After the classification procedure, discriminated spectral classes were generalized into 12 peatland types. Overall accuracy assessment was based on 439 randomly assigned test sites showing final map accuracy was 80%. Total peatland area was estimated at 73.0 Mha. Various ridge

Landsat imagery evidences great recent land cover changes induced by wild fires in central Siberia*

NASA Astrophysics Data System (ADS)

Antamoshkina, O. A.; Trofimova, N. V.; Antamoshkin, O. A.

2016-04-01

The article discusses the methods of satellite image classification to determine general types of forest ecosystems, as well as the long-term monitoring of ecosystems changes using satellite imagery of medium spatial resolution and the daily data of space monitoring of active fires. The area of interest of this work is 100 km footprint of the Zotino Tall Tower Observatory (ZOTTO), located near the Zotino settlement, Krasnoyarsk region. The study area is located in the middle taiga subzone of Western Siberia, are presented by the left and right banks of the Yenisei river. For Landsat satellite imagery supervised classification by the maximum likelihood method was made using ground-based studies over the last fifteen years. The results are the identification of the 10 aggregated classes of land surface and composition of the study area thematic map. Operational satellite monitoring and analysis of spatial information about ecosystem in the 100-kilometer footprint of the ZOTTO tall tower allows to monitor the dynamics of forest disturbance by fire and logging over a long time period and to estimate changes in forest ecosystems of the study area. Data on the number and area of fires detected in the study region for the 2000-2014 received in the work. Calculations show that active fires have burned more than a quarter of the footprint area over the study period. Fires have a significant impact on the redistribution of classes of land surface. Area of all types of vegetation ecosystems declined dramatically under the influence of fires, whereas industrial logging does not impact seriously on it. The results obtained in our work indicate the highest occurrence of fires for lichen forest types within study region, probably due to their high natural fire danger, which is consistent with other studies. The least damage the fire caused to the wetland ecosystem due to high content of moisture and the presence of a large number of fire breaks in the form of open water.

Sequence stratigraphy and environmental background of the late Pleistocene and Holocene occupation in the Southeast Primor'ye (the Russian Far East)

NASA Astrophysics Data System (ADS)

Chlachula, Jiri; Krupyanko, Alexander A.

2016-06-01

The paper presents the results of Quaternary palaeoecology and geoarchaeology studies in the Zerkal'naya Basin, with new insights about sequenced natural shifts during the prehistoric occupation of this marginally explored NE Asian maritime territory. The Basin is part of the continental drainage system and the main physiographic and biotic corridor for peopling of the transitive coastal interior SE Primor'ye Region. The Final Pleistocene and Holocene environmental (biotic and abiotic) proxy records from the Upper/Final Palaeolithic to early historical sites document a dynamic climate change with vegetation cover transformations within riverine and mountain valley ecosystems of the Russian Far East. Most of the archaeological sites located on the low terraces and bedrock promontories along the main river channel and its tributary streams suggest traditional hunter gathered lifestyles based on seasonal salmon-fishing supplemented by pastoral economy. Tundra-forests with larch trees, dwarf birch thickets and polypod ferns from the basal stratigraphic units of the late Last Glacial occupation sites associated with the Upper Palaeolithic micro-blade and bifacial stone tool traditions (14C-dated to 19,000-12,000 cal yrs BP) indicate rather pronounced conditions and much lower MAT comparing today. Following a final Pleistocene cooling event, a major climate warming marked the onset of Holocene accompanied by a regional humidity increase promoting the formation of a mixed broadleaved-coniferous oak-dominant taiga, and culminating in the mid-Holocene Climatic Optimum. The appearance of mosaic parklands ca. 5,000-4,000 cal yrs BP. may be partly attributed to the expansion of the Far Eastern Neolithic cultures practicing forest clearance for pastures and dwellings. A progressing landscape opening indicated by the spread of light-demanding thickets and birch-dominated riverine biotopes with Artemisia suggests a further vegetation cover transformation during the late Neolithic

The effect to the water stress to soil CO2 efflux in the Siberian boreal forest

NASA Astrophysics Data System (ADS)

Makhnykina, A. V.; Prokishkin, A. S.; Verkhovets, S. V.; Koshurnikova, N. N.

2017-12-01

The boreal forests in Siberia covered more than 70% area of this region. Due to the climate change this ecosystems represent a very sensitive and significant source of carbon. In forests, total ecosystem respiration tends to be dominated by soil respiration, which accounts for approximately 69% of this large flux (Janssens et al., 2001). Dynamic global vegetation models predict that soil respiration will increase more than total net primary productivity in response to warmer temperatures and increase in precipitation, the terrestrial carbon sink is expected to decline significantly (Bonan et al., 2003). The aim of the present study was to identify the response of the soil CO2 efflux to the different amount of water input for two highly differentiated years by the precipitation conditions in the middle taiga forests in Central Siberia. The study was conducted in the pine forests in Central Siberia (60°N, 90°E), Russia. We used the automated soil CO2 flux system LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths 5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. We constructed the field experiment based on the addition of different amount of water (0%, 25%, 50% and 100% sites) after each rain event during the growing season. We found that the amount of precipitation have a huge impact to the value of soil CO2 efflux. For the more precipitated year (2015) the fluxes were almost twice higher compared to less precipitated year (2016). The max fluxes during the season in 2015 observed at the site without any water input there and the min one - for the 100% precipitation site (natural rain conditions). In 2016 we identified the opposite response: the max soil efflux demonstrated the site with 100% precipitation conditions (Fig. 1). We also detected the high dependence between the soil temperature and soil CO2 efflux for the site with 0% additional water input in more

NATURAL RADIOACTIVITY OF ZONAL SOILS OF THE EUROPEAN PART OF THE SOVIET UNION (in Russian)

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

Yastrebov, M.T.

1959-01-01

Natural radioactivity of zonal soils and of their soil forming rocks up to 220-240 cm in depth as well as of the suprasoil air at a 20 cm altitude from the soil surface has been studled from 29.VM to 13.X 1957 in the natural zones of the European part of the USSR located along the meridian from the Arkhangelsk taiga down to the southern coast of Crimea. The measurements were carried out by mica counters (BFL-T-80 and Si-2b), by an aluminum (AS-2) and glass copper cathode (MS-4) which registers alpha , BETA -soft, BETA -hard and gamma - radiation, respectivelymore » with the aid of a field radiometric device PK-10b and a spherical and hemispherical 9-cm lead shield. It was found that natural radioactivity of zonal soils increased in the following order: highly podzol on carbonate moraine (Arkhangelsk region), sod-highly podzol soil on loess-like loam (Vologodsk region), sodmedium podzol soil on loess-like loam (Moscow region), light-gray forest soil on loess loam (Tula region), powerful leached chernozem on loess-like loam (Kursk region), dark chestnut on carbonate loess-like loam (Kherson region) brown forest on slate schists (Crimea region). A 5-mm superficial layer of the accumulative A: horizon invariably showed maximal natural radioactivity in all kinds of soil surpassing the natural radioactivity value of the lower A/sub 1/ horizon and of all soil horizons and rocks by 2.2-3.5 times. In the podzol A/sub 2/ horizons a decrease of natural radioactivity was mostiy noted as compared with the natural radioactivity value of the accumulative Ai horizon. In the alluvial horizon (B/sub 1/ and B/sub 2/) natural radioactivity increases by 12 to 33% when compared with natural radioactivity of the A: horizon. Most of the soilforming rocks tested showed a lesser natural radioactivity (by 33 to 50%) than natural radioactivity of the accumulative (A/ sub 1/) and alluvial (B/sub 1/ and B/sub 2/) soil horizons which have developed on these rocks. (auth)« less

The positive net radiative greenhouse gas forcing of increasing methane emissions from a thawing boreal forest-wetland landscape.

PubMed

Helbig, Manuel; Chasmer, Laura E; Kljun, NatasCha; Quinton, William L; Treat, Claire C; Sonnentag, Oliver

2017-06-01

At the southern margin of permafrost in North America, climate change causes widespread permafrost thaw. In boreal lowlands, thawing forested permafrost peat plateaus ('forest') lead to expansion of permafrost-free wetlands ('wetland'). Expanding wetland area with saturated and warmer organic soils is expected to increase landscape methane (CH 4 ) emissions. Here, we quantify the thaw-induced increase in CH 4 emissions for a boreal forest-wetland landscape in the southern Taiga Plains, Canada, and evaluate its impact on net radiative forcing relative to potential long-term net carbon dioxide (CO 2 ) exchange. Using nested wetland and landscape eddy covariance net CH 4 flux measurements in combination with flux footprint modeling, we find that landscape CH 4 emissions increase with increasing wetland-to-forest ratio. Landscape CH 4 emissions are most sensitive to this ratio during peak emission periods, when wetland soils are up to 10 °C warmer than forest soils. The cumulative growing season (May-October) wetland CH 4 emission of ~13 g CH 4  m -2 is the dominating contribution to the landscape CH 4 emission of ~7 g CH 4  m -2 . In contrast, forest contributions to landscape CH 4 emissions appear to be negligible. The rapid wetland expansion of 0.26 ± 0.05% yr -1 in this region causes an estimated growing season increase of 0.034 ± 0.007 g CH 4  m -2  yr -1 in landscape CH 4 emissions. A long-term net CO 2 uptake of >200 g CO 2  m -2  yr -1 is required to offset the positive radiative forcing of increasing CH 4 emissions until the end of the 21st century as indicated by an atmospheric CH 4 and CO 2 concentration model. However, long-term apparent carbon accumulation rates in similar boreal forest-wetland landscapes and eddy covariance landscape net CO 2 flux measurements suggest a long-term net CO 2 uptake between 49 and 157 g CO 2  m -2  yr -1 . Thus, thaw-induced CH 4 emission increases likely exert a positive net radiative greenhouse gas

Use of pine nuts by grizzly and black bears in the Yellowstone area

USGS Publications Warehouse

Kendall, Katherine C.

1983-01-01

The large seeds (pine nuts) of whitebark pine are commonly eaten in the spring (March-May) and fall (September-November) by grizzly and black bears in Yellowstone National Park and adjacent areas (Craighead and Craighead 1972, Blanchard 1978, Mealey 1980) and western Montana (Tisch 1961; J. Sumner and J. J. Craighead, unpubl. rep., Montant Coop. Wildl. Res. Unit, Univ. Montana, Missoula, 1973). Similar nuts from limber pine are eaten by grizzly bears on the east Rocky Mountain Front of northwestern Montana (Schallenberger and Jonkel, annual rep., Border Grizzly Project, Univ. Montana, Missoula, 1980). The nuts of the European stone pine (P. cembra) are an important food for brown bears (U. arctos) throughout the taiga zone in the Soviet Union (Pavlov and Zhdanov 1972, Ustinov 1972, Yazan 1972). Both the production of whitebark pine cones (Forcella 1977, Blanchard 1978, Mealey 1980) and the quantity of nuts consumed by bears vary annually (Mealey 1975, Blancard 1978). Pine nuts are also an important food for red squirrels in whitebark forests. In fall, squirrels remove cones from trees and cache them in middens. Bears as well as other mammalian and avian seed predators compete with squirrels for whitebark nuts (Forcella 1977, Tomback 1977). Confusion about the ripening process of whitebark pine cones has resulted in errors in the literature on the availability of pine nuts as a bear food. Whitebark cones are indehiscent and do not disintegrate (Tomback 1981). Vertebrate foraging probably leaves few, if any, seed-bearing cones on trees by late fall; the cones remaining abscise sometime thereafter (Tomback 1981). Because cones do not abscise or release their seed in fall, bears may obtain pine nuts in 2 ways. Black bears may climb whitebark pine trees and break off cone-bearing brnahces to feed on cones (Tisch 1961, Mealey 1975, Forcella 1977); or both black bears and grizzly bears may raid squirrel caches to feed on pine nuts (Tisch 1961, Craighead and Craighead 1972

High-resolution mapping and spatial variability of soil organic carbon storage of permafrost-affected soils

NASA Astrophysics Data System (ADS)

Siewert, Matthias; Hugelius, Gustaf

2017-04-01

Permafrost-affected soils store large amounts of soil organic carbon (SOC). Mapping of this SOC provides a first order spatial input variable for research that relates carbon stored in permafrost regions to carbon cycle dynamics. High-resolution satellite imagery is becoming increasingly available even in circum-polar regions. The presented research highlights findings of high-resolution mapping efforts of SOC from five study areas in the northern circum-polar permafrost region. These study areas are located in Siberia (Kytalyk, Spasskaya Pad /Neleger, Lena delta), Northern Sweden (Abisko) and Northwestern Canada (Herschel Island). Our high spatial resolution analyses show how geomorphology has a strong influence on the distribution of SOC. This is organized at different spatial scales. Periglacial landforms and processes dictate local scale SOC distribution due to patterned ground. Such landforms are non-sorted circles and ice-wedge polygons of different age and scale. Palsas and peat plateaus are formed and can cover larger areas in Sub-Arctic environments. Study areas that have not been affected by Pleistocene glaciation feature ice-rich Yedoma sediments that dominate the local relief through thermokarst formation and create landscape scale macro environments that dictate the distribution of SOC. A general trend indicates higher SOC storage in Arctic tundra soils compared to forested Boreal or Sub-Arctic taiga soils. Yet, due to the shallower active layer depth in the Arctic, much of the SOC may be permanently frozen and thus not be available to ecosystem processes. Significantly more SOC is stored in soils compared to vegetation, indicating that vegetation growth and incorporation of the carbon into the plant phytomass alone will not be able to offset SOC released from permafrost. This contribution also addresses advances in thematic mapping methods and digital soil mapping of SOC in permafrost terrain. In particular machine-learning methods, such as support

Database of in-situ field measurements for estimates of fuel consumption and fire emissions in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Buryak, Ludmila; Ivanova, Galina; Soja, Amber; Kalenskaya, Olga; Zhila, Sergey; Zarubin, Denis; Groisman, Pavel

2016-04-01

Wildfires show great variability in the amount of fuel consumed and carbon emitted to the atmosphere. Various types of models are used to calculate global or large scale regional fire emissions. However, in the databases used to estimate fuel consumptions, data for Russia are typically under-represented. Meanwhile, the differences in vegetation and fire regimes in the boreal forests in North America and Eurasia argue strongly for the need of regional ecosystem-specific data. For about 15 years we have been collecting field data on fuel loads and consumption in different ecosystem types of Siberia. We conducted a series of experimental burnings of varying fireline intensity in Scots pine and larch forests of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions. In addition, we examined wildfire behavior and effects in different vegetation types including Scots pine, Siberian pine, fir, birch, poplar, and larch-dominated forests; evergreen coniferous shrubs; grasslands, and peats. We investigated various ecosystem zones of Siberia (central and southern taiga, forest-steppe, steppe, mountains) in the different subjects of the Russian Federation (Krasnoyarsk Kray, Republic of Khakassia, Republic of Buryatia, Tuva Republic, Zabaikalsky Kray). To evaluate the impact of forest practices on fire emissions, burned and unburned logged sites and forest plantations were examined. We found large variations of fuel consumption and fire emission rates among different vegetation types depending on growing conditions, fire behavior characteristics and anthropogenic factors. Changes in the climate system result in an increase in fire frequency, area burned, the number of extreme fires, fire season length, fire season severity, and the number of ignitions from lightning. This leads to an increase of fire-related emissions of carbon to the atmosphere. The field measurement database we compiled is required for improving accuracy of existing

Plant response to climate change along the forest-tundra ecotone in northeastern Siberia.

PubMed

Berner, Logan T; Beck, Pieter S A; Bunn, Andrew G; Goetz, Scott J

2013-11-01

Russia's boreal (taiga) biome will likely contract sharply and shift northward in response to 21st century climatic change, yet few studies have examined plant response to climatic variability along the northern margin. We quantified climate dynamics, trends in plant growth, and growth-climate relationships across the tundra shrublands and Cajander larch (Larix cajanderi Mayr.) woodlands of the Kolyma river basin (657 000 km(2) ) in northeastern Siberia using satellite-derived normalized difference vegetation indices (NDVI), tree ring-width measurements, and climate data. Mean summer temperatures (Ts ) increased 1.0 °C from 1938 to 2009, though there was no trend (P > 0.05) in growing year precipitation or climate moisture index (CMIgy ). Mean summer NDVI (NDVIs ) increased significantly from 1982 to 2010 across 20% of the watershed, primarily in cold, shrub-dominated areas. NDVIs positively correlated (P < 0.05) with Ts across 56% of the watershed (r = 0.52 ± 0.09, mean ± SD), principally in cold areas, and with CMIgy across 9% of the watershed (r = 0.45 ± 0.06), largely in warm areas. Larch ring-width measurements from nine sites revealed that year-to-year (i.e., high-frequency) variation in growth positively correlated (P < 0.05) with June temperature (r = 0.40) and prior summer CMI (r = 0.40) from 1938 to 2007. An unexplained multi-decadal (i.e., low-frequency) decline in annual basal area increment (BAI) occurred following the mid-20th century, but over the NDVI record there was no trend in mean BAI (P > 0.05), which significantly correlated with NDVIs (r = 0.44, P < 0.05, 1982-2007). Both satellite and tree-ring analyses indicated that plant growth was constrained by both low temperatures and limited moisture availability and, furthermore, that warming enhanced growth. Impacts of future climatic change on forests near treeline in Arctic Russia will likely be influenced by shifts in both temperature and moisture, which implies

Impact of raized bogs on export of carbon and river water chemical composition in Western Siberia

NASA Astrophysics Data System (ADS)

Voistinova, Elena

2010-05-01

Bogs play an important role in functioning of the biosphere. Specific geochemical environment of the bogs results in formation of the special biogeochemical cycle of the elements. Processes of decay and transformation of organic material define the reductive conditions of bog water, form and migratory mobility of the chemical elements. Particular interest in recent years is aroused by the question of content and dynamics of the carbon in bog and river water according to indicated natural and climatic changes on the territory. The most important parts of the carbon balance in bog ecosystems together with processes of exhalation from deposit surface in the form of CO2 is its export with river water. The results of research carried out in scientific station "Vasyugansky" in south taiga subzone of Western Siberia showed that chemical composition of raised bog water includes high amounts of total iron (2,13 mg/l), ammonium ions (5,33 mg/l), humic and fulvic acids (5,21 mg/l and 45,8 mg/l), dissolved organic carbon (69,1 mg/l), COD (236,93 mgO/l), there are low mineralization and indicators of pH. Carbon comes in bog water in organic compounds: carboxylic acids, phenols, aromatic and paraffin hydrocarbons, organic phosphates, phthalates and other compounds. Formation of river waters composition in the Western Siberia takes place in the following context: high level of bogged river catchments (sometimes up to 70%), excess humidification and low heat provision. Basing on the results of study of hydrochemical runoff in small and medium rivers with different levels of bogged in river catchments (Chaya, Bakchar, Klyuch, Gavrilovka) it was noted that raised bog influence on river waters chemical composition shows in ion runoff decrease, organic substances runoff increase, increase of amounts of total iron, ammonium irons and water pH indicators decrease. Study of humic matters migration is very important in the context of formation of flexible complexes of humic and fulvic

Revealing Interactions between Human Resources, Quality of Life and Environmental Changes within Socially-oriented Observations : Results from the IPY PPS Arctic Project in the Russian North

NASA Astrophysics Data System (ADS)

Vlasova, Tatiana

2010-05-01

Socially-oriented Observations (SOO) in the Russian North have been carried out within multidisciplinary IPY PPS Arctic project under the leadership of Norway and supported by the Research Council of Norway as well as Russian Academy of Sciences. The main objective of SOO is to increase knowledge and observation of changes in quality of life conditions (state of natural environment including climate and biota, safe drinking water and foods, well-being, employment, social relations, access to health care and high quality education, etc.) and - to reveal trends in human capital and capacities (health, demography, education, creativity, spiritual-cultural characteristics and diversity, participation in decision making, etc.). SOO have been carried out in industrial cities as well as sparsely populated rural and nature protection areas in observation sites situated in different bioms (from coastal tundra to southern taiga zone) of Murmansk, Arkhangelsk Oblast and Republic of Komi. SOO were conducted according to the international protocol included in PPS Arctic Manual. SOO approaches based both on local people's perceptions and statistics help to identify main issues and targets for life quality, human capital and environment improvement and thus to distinguish leading SOO indicators for further monitoring. SOO have revealed close interaction between human resources, quality of life and environmental changes. Negative changes in human capital (depopulation, increasing unemployment, aging, declining physical and mental health, quality of education, loss of traditional knowledge, marginalization etc.), despite peoples' high creativity and optimism are becoming the major driving force effecting both the quality of life and the state of environment and overall sustainability. Human induced disturbances such as uncontrolled forests cuttings and poaching are increasing. Observed rapid changes in climate and biota (ice and permafrost melting, tundra shrubs getting taller and

Features of Scots pine radial growth in conditions of provenance trial.

NASA Astrophysics Data System (ADS)

Kuzmin, Sergey; Kuzmina, Nina

2013-04-01

) climatype from northern taiga with good resistance to pathogen have nonsignificant decline in radial increment during epiphytoty in comparison with local and southern climatypes. Southern Chemal provenance (Altai) after influence of Cenangium dieback has more than others losses of tree rings as the result of nonresistance to this fungal disease.

The Last Glacial Ecosystems of North Siberia: Permafrost-Sealed Evidence from Fossiliferous Cryolithic Formations

NASA Astrophysics Data System (ADS)

Chlachula, Jiri

2017-04-01

Multi-proxy palaeoecology and geoarchaeology records released from degrading permafrost in the Yana River Basin and the tributary valleys (66-67°N) confirm the past existence of natural conditions for sustainment of the Pleistocene megafauna as well as the last glacial peopling of this sub-polar area. Well-preserved and taxonomically diverse large fossil fauna skeletal remains sealed in the Pleistocene colluvial and alluvial-plain formations in intact geological positions 10-20 m above the present river and scattered on gravelly river banks after their erosion from the primary geo-contexts attest to a high biotic potential of the Late Pleistocene (MIS 3-2) sub-Arctic forest-tundra. Pollen records from the ancient interstratified boggy sediments and megafauna coprolites (14C-dated to 41-38 ka BP) show a predominance of the Siberian larch, dwarf birch and willow in the local vegetation cover accompanied by grassy communities during the mid-Last Glacial stage not dissimilar from the present northern taiga forest. Articulated and humanly used/worked fauna bones (mammoth, rhinoceros, horse, bison and reindeer among other species) point to co-existence of the large animals with the Upper Palaeolithic people within the mosaic open riverine ecosystems of the late Last Ice Age. The time-trangressive macro-lithic stone industry produced from pre-selected river gravel cobbles document some specific ways of human environmental adjustment to past periglacial settings. Geomorphology and hydrogeology indices of field mappings in congruence with the long-term statistical meteorology data illustrate a steadily increasing annual temperature trend in the broader Yana-Adycha Basins (current MAT -14.5°C) that triggers accelerated permafrost thaw across the Verkhoyansk Region of NE Siberia, particularly the lowlands, similarly as in the Indigirka and Kolyma Basins further East. The regional fluvial discharge is most dynamic during late spring due to the cumulative effects of snow

Latitude and pH driven trends in the molecular composition of DOM across a north south transect along the Yenisei River

NASA Astrophysics Data System (ADS)

Roth, Vanessa-Nina; Dittmar, Thorsten; Gaupp, Reinhard; Gleixner, Gerd

2013-12-01

We used electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) to identify the molecular composition of dissolved organic matter (DOM) collected from different ecosystems along a transect crossing Siberia’s northern and middle Taiga. This information is urgently needed to help elucidate global carbon cycling and export through Russian rivers. In total, we analyzed DOM samples from eleven Yenisei tributaries and seven bogs. Freeze-dried and re-dissolved DOM was desalted via solid phase extraction (SPE) and eluted in methanol for ESI-FT-ICR-MS measurements. We recorded 15209 different masses and identified 7382 molecular formulae in the mass range between m/z = 150 and 800. We utilized the relative FT-ICR-MS signal intensities of 3384 molecular formulae above a conservatively set limit of detection and summarized the molecular characteristics for each measurement using ten magnitude-weighted parameters ((O/C)w, (H/C)w, (N/C)w, (DBE)w, (DBE/C)w, (DBE/O)w, (DBE-O)w, (C#)w, (MW)w and (AI)w) for redundancy analysis. Consequently, we revealed that the molecular composition of DOM depends mainly on pH and geographical latitude. After applying variation partitioning to the peak data, we isolated molecular formulae that were strongly positive or negatively correlated with latitude and pH. We used the chemical information from 13 parameters (C#, H#, N#, O#, O/C, H/C, DBE, DBE/C, DBE/O, AI, N/C, DBE-O and MW) to characterize the extracted molecular formulae. Using latitude along the gradient representing climatic variation, we found a higher abundance of smaller molecules, nitrogen-containing compounds and unsaturated Cdbnd C functionalities at higher latitudes. As possible reasons for the different molecular characteristics occurring along this gradient, we suggested that the decomposition was temperature dependent resulting to a higher abundance of non-degraded lignin-derived phenolic substances. We demonstrated that bog samples

High-Resolution Regional Biomass Map of Siberia from Glas, Palsar L-Band Radar and Landsat Vcf Data

NASA Astrophysics Data System (ADS)

Sun, G.; Ranson, K.; Montesano, P.; Zhang, Z.; Kharuk, V.

2015-12-01

The Arctic-Boreal zone is known be warming at an accelerated rate relative to other biomes. The taiga or boreal forest covers over 16 x106 km2 of Arctic North America, Scandinavia, and Eurasia. A large part of the northern Boreal forests are in Russia's Siberia, as area with recent accelerated climate warming. During the last two decades we have been working on characterization of boreal forests in north-central Siberia using field and satellite measurements. We have published results of circumpolar biomass using field plots, airborne (PALS, ACTM) and spaceborne (GLAS) lidar data with ASTER DEM, LANDSAT and MODIS land cover classification, MODIS burned area and WWF's ecoregion map. Researchers from ESA and Russia have also been working on biomass (or growing stock) mapping in Siberia. For example, they developed a pan-boreal growing stock volume map at 1-kilometer scale using hyper-temporal ENVISAT ASAR ScanSAR backscatter data. Using the annual PALSAR mosaics from 2007 to 2010 growing stock volume maps were retrieved based on a supervised random forest regression approach. This method is being used in the ESA/Russia ZAPAS project for Central Siberia Biomass mapping. Spatially specific biomass maps of this region at higher resolution are desired for carbon cycle and climate change studies. In this study, our work focused on improving resolution ( 50 m) of a biomass map based on PALSAR L-band data and Landsat Vegetation Canopy Fraction products. GLAS data were carefully processed and screened using land cover classification, local slope, and acquisition dates. The biomass at remaining footprints was estimated using a model developed from field measurements at GLAS footprints. The GLAS biomass samples were then aggregated into 1 Mg/ha bins of biomass and mean VCF and PALSAR backscatter and textures were calculated for each of these biomass bins. The resulted biomass/signature data was used to train a random forest model for biomass mapping of entire region from 50o

Late Pleniglacial vegetation in eastern-central Europe: are there modern analogues in Siberia?

NASA Astrophysics Data System (ADS)

Magyari, Enikő Katalin; Kuneš, Petr; Jakab, Gusztáv; Sümegi, Pál; Pelánková, Barbora; Schäbitz, Frank; Braun, Mihály; Chytrý, Milan

2014-07-01

To characterize Late Pleniglacial (LPG: 26.5-15 ka cal BP) and particularly Last Glacial Maximum (LGM: 21 ± 2 ka cal BP) vegetation and climate, fossil pollen assemblages are often compared with modern pollen assemblages. Given the non-analogue climate of the LPG, a key question is how glacial pollen assemblages and thereby vegetation compare with modern vegetation. In this paper we present three LPG pollen records from the Carpathian Basin and the adjoining Carpathian Mountains to address this question and provide a concise compositional characterization of the LPG vegetation. Fossil pollen assemblages were compared with surface pollen spectra from the Altai-Sayan Mountains in southern Siberia. This area shows many similarities with the LPG vegetation of eastern-central Europe, and has long been considered as its best modern analogue. Ordination and analogue matching were used to characterize vegetation composition and find the best analogues. Our results show that few LPG pollen assemblages have statistically significant analogues in southern Siberia. When analogue pairings occur they suggest the predominance of wet and mesic grasslands and dry steppe in the studied region. Wooded vegetation types (continental and suboceanic hemiboreal forest, continental taiga) appear as significant analogues only in a few cases during the LGM and more frequently after 16 ka cal BP. These results suggest that the LPG landscape of the Carpathian Basin was dominated by dry steppe that occurred outside the river floodplains, while wet and mesic grasslands occurred in the floodplains and on other sites influenced by ground water. Woody vegetation mainly occurred in river valleys, on wet north-facing hillsides, and scattered trees were likely also present on the loess plateaus. The dominant woody species were Larix, Pinus sylvestris, Pinus mugo, Pinus cembra, Picea abies, Betula pendula/pubescens, Betula nana, Juniperus, Hippophaë rhamnoides, Populus, Salix and Alnus. The pollen

A pollen-based biome reconstruction over the last 3.562 million years in the Far East Russian Arctic - new insights into climate-vegetation relationships at the regional scale

NASA Astrophysics Data System (ADS)

Tarasov, P. E.; Andreev, A. A.; Anderson, P. M.; Lozhkin, A. V.; Leipe, C.; Haltia, E.; Nowaczyk, N. R.; Wennrich, V.; Brigham-Grette, J.; Melles, M.

2013-12-01

The recent and fossil pollen data obtained under the frame of the multi-disciplinary international El'gygytgyn Drilling Project represent a unique archive, which allows the testing of a range of pollen-based reconstruction approaches and the deciphering of changes in the regional vegetation and climate. In the current study we provide details of the biome reconstruction method applied to the late Pliocene and Quaternary pollen records from Lake El'gygytgyn. All terrestrial pollen taxa identified in the spectra from Lake El'gygytgyn were assigned to major vegetation types (biomes), which today occur near the lake and in the broader region of eastern and northern Asia and, thus, could be potentially present in this region during the past. When applied to the pollen spectra from the middle Pleistocene to present, the method suggests (1) a predominance of tundra during the Holocene, (2) a short interval during the marine isotope stage (MIS) 5.5 interglacial distinguished by cold deciduous forest, and (3) long phases of taiga dominance during MIS 31 and, particularly, MIS 11.3. These two latter interglacials seem to be some of the longest and warmest intervals in the study region within the past million years. During the late Pliocene-early Pleistocene interval (i.e., ~3.562-2.200 Ma), there is good correspondence between the millennial-scale vegetation changes documented in the Lake El'gygytgyn record and the alternation of cold and warm marine isotope stages, which reflect changes in the global ice volume and sea level. The biome reconstruction demonstrates changes in the regional vegetation from generally warmer/wetter environments of the earlier (i.e., Pliocene) interval towards colder/drier environments of the Pleistocene. The reconstruction indicates that the taxon-rich cool mixed and cool conifer forest biomes are mostly characteristic of the time prior to MIS G16, whereas the tundra biome becomes a prominent feature starting from MIS G6. These results

Using RAQMS Chemical Transport Model, Aircraft In-situ and Satellite Data to Verify Ground-based Biomass Burning Emissions from the Extreme Fire Event in Boreal Alaska 2004

NASA Astrophysics Data System (ADS)

Soja, A. J.; Pierce, R. B.; Al-Saadi, J. A.; Alvarado, E.; Sandberg, D. V.; Ottmar, R. D.; Kittaka, C.; McMillian, W. W.; Sachse, G. W.; Warner, J. X.; Szykman, J. J.

2006-12-01

Current climate change scenarios are predicted to result in increased biomass burning, particularly in boreal regions. Biomass burning events feedback to the climate system by altering albedo (affecting the energy balance) and by direct and indirect fire emissions. Additionally, fire emissions influence air quality and human health downwind of burning. Biomass burning emission estimates are difficult to quantify in near-real-time and accurate estimates are useful for large-scale chemical transport models, which could be used to warn the public of potential health risks and for climate modeling. In this talk, we describe a methodology to quantify emissions, validate those emission estimates, transport the emissions and verify the resultant CO plume 100's of kilometers from the fire events using aircraft in-situ and satellite data. First, we developed carbon consumption estimates that are specifically designed for near-real-time use in conjunction with satellite-derived fire data for regional- to global-chemical transport models. Large-scale carbon consumption estimates are derived for 10 ecozones across North America and each zone contains 3 classes of severity. The estimates range is from a low severity 3.11 t C ha-1 estimate from the Western Taiga Shield to a high severity 59.83 t C ha-1 estimate from the Boreal Cordillera. These estimates are validated using extensive supplementary ground-based Alaskan data. Then, the RAQMS chemical transport model ingests these data and transports CO from the Alaskan 2004 fires across North America, where results are compared with in-situ flight CO data measured during INTEX-A and satellite-based CO data (AIRS and MOPITT). Ground-based CO is 6 to 14 times greater than the typically modeled fire climatology. RAQMS often overestimates CO in the biomass plumes in comparison to satellite- derived CO data and we suspect this may be due to the satellite instruments low sensitivity to planetary boundary layer CO, which is prevalent in

Space Radar Image of Kliuchevskoi, Russia

NASA Image and Video Library

1999-05-01

This is an X-band seasonal image of the Maly Semlyachik volcano, which is part of the Karymsky volcano group on Kamchatka peninsula, Russia. The image is centered at 54.2 degrees north latitude and 159.6 degrees east longitude. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on April 9, 1994, during the first flight of the radar system, and on September 30, 1994, during the second flight. The image channels have been assigned the following colors: red corresponds to data acquired on April 9; green corresponds to data acquired on September 30; and blue corresponds to the ratio between data from April 9 and September 30, 1994. Kamchatka is twice as large as England, Scotland and Wales combined and is home to approximately 470,000 residents. The region is characterized by a chain of volcanoes stretching 800 kilometers (500 miles) across the countryside. Many of the volcanoes, including the active Maly Semlyachik volcano in this image, have erupted during this century. But the most active period in creating the three characteristic craters of this volcano goes back 20,000, 12,000 and 2,000 years ago. The highest summit of the oldest crater reaches about 1,560 meters (1,650 feet). The radar images reveal the geological structures of craters and lava flows in order to improve scientists' knowledge of these sometimes vigorously active volcanoes. This seasonal composite also highlights the ecological differences that have occurred between April and October 1994. In April the whole area was snow-covered and, at the coast, an ice sheet extended approximately 5 kilometers (3 miles) into the sea. The area shown surrounding the volcano is covered by low vegetation much like scrub. Kamchatka also has extensive forests, which belong to the northern frontier of Taiga, the boreal forest ecosystem. This region plays an important role in the world's carbon cycle. Trees require 60 years to

Investigation of radionuclide distribution in soil particles in different landscapes

NASA Astrophysics Data System (ADS)

Shkinev, V. M.; Korobova, E. M.; Linnik, V. G.

2012-04-01

Russian and foreign publications have been analyzed for understanding the role of micro- and nano- particles in distribution and migration of technogenic elements in soils in different landscape conditions. A technique for application of various fractionation methods to separate and study -particles of different size down to micro- and nano-level has been developed. The dry sit method on the first stage of particle separation is recommend to be followed by the membrane filtration method. For obtaining more comprehensive information, combinations of fractionation technique should be chosen taking into account that (1) the efficiency of particles' separation using subsequent technique would be higher than using the preceding one; (2) separation methods should preferably be based on different principles (separation according size, density, charge etc.); (3) initial fractionation should separate particles according to their size, that makes possible to create an even scale for various samples. A study of distribution and balance of technogenic radionuclides' in soil particles of the size intervals 1.0—0.25, 0.25-0.1, 0.1-0.05, 0.05-0.01, 0.01-0.005, 0.005-0.001 and <0.001 mm in the Yenisey flood plain landscapes proved a significant role of both the particle size and the portion of contaminated fraction in contribution to the total radionuclide inventory in the soil layers. Contribution of the silt particles (0,05-0,01 mm) to Cs-137 contamination ranged from 26 to 33,8%, 45% maximum due to "optimal" combination of both factors. Clay fraction was responsible for approximately 30% of Cs-137 contained in soil horizons due to higher sorption capacity. Relatively high correlation between the activity of 152,154Eu and 60 and the content of silt and clay allowed suggesting their incorporation mainly in clay fraction. Selected experimental plots near the Kola NPP (northern taiga) were used to compare soil particles (fractions 140-71; 71-40 and < 40 µm) in their ability to

Climate change and water resources in northern Mongolia

NASA Astrophysics Data System (ADS)

Menzel, Lucas; Törnros, Tobias; Marberg, Ines

2014-05-01

Mongolia is facing a large number of water-related problems, such as adverse natural conditions, increasing water withdrawals, scarce environmental information and a lack of structures which control the appropriate distribution and protection of water. Since 2010, we conduct a monitoring programme in northern Mongolia which aims at better understanding the climatic characteristics, the freshwater generating processes as well as the impact of environmental change on the water resources in a semi-arid environment. Focus is on the meso-scaled Kharaa catchment (14,500 km²) north of Ulaanbaatar which includes the transition belt between the extended steppe ecotone, the Siberian taiga as well as the alpine tundra of the Khentii Mountains which act as the major freshwater generating area of the region. Based on the information gained during our field studies, we successfully applied the hydrological HBV-D model to simulate the discharge at the outlet of the basin and for a number of sub-basins. We could show that runoff within the study region is strongly influenced by the high climate variability. For example, the observed runoff in the basin shows a sudden decrease in the middle 1990s. At the same time, precipitation is decreasing and temperature is strongly increasing. The study is based on data from only six meteorological stations. Therefore, output from Global Climate Models has been considered as another potential data source. Accordingly, the HBV-D model was driven with WATCH forcing data for the years 1901-2000. This made it possible to simulate the runoff for years where no runoff observations exist. The results show that mean annual air temperature (MAT) has been strongly rising during the last 100 years (for example, between 1940 and 2001 MAT increased by 1.7°C) while precipitation shows strong, long-term oscillations. Accordingly, simulated mean annual discharge shows a high temporal variability with high fluctuations during the first half of the 20th

The Demise of the Circumboreal Mammoth Steppe as an Ecological Regime Shift: Drivers and Consequences

NASA Astrophysics Data System (ADS)

Mann, D. H.; Groves, P.; Grosse, G.; Gaglioti, B.; Kunz, M.

2011-12-01

During the last ice age, the now-vanished Mammoth Steppe stretched from the Yukon westward to Europe and supported a unique guild of megafauna grazers including mammoth, bison, saiga, wooly rhinoceros, caribou, muskox, and horse. The detailed vegetational composition of this extinct biome remains uncertain because of its large size and temporal complexity during multiple climatic shifts. Grasses and sedges were prominent, and Mammoth Steppe vegetation was probably more spatially variable than the tundra and taiga vegetation that replaced it. The environmental factors that maintained the Mammoth Steppe and dictated its variability over time and space are poorly understood. Here we present evidence for an expanded version of the "Schweger Hypothesis", the idea that large regions of the Mammoth Steppe were created and maintained by processes associated with aeolian sediment activity that was driven by enhanced pressure gradients in the full-glacial atmosphere and by increased continentality caused by lowered sea level. Increased seasonal swings in climate plus stronger winds interacted to promote the widespread occurrence of steppe-like vegetation that grew on relatively inactive and marginal dune and loess deposits. Subsequent periods of resumed aeolian deposition or reworking would have inhibited thick organic horizon development which are largely absent from full glacial mammoth steppe. New mapping of sand dune systems in Siberia and improved chronological control over dune fields in Alaska demonstrate the presence of large dune fields and loess belts in the regions occupied by the Mammoth Steppe during the Last Glacial Maximum. In regions of north Siberia, intense periglacial weathering and local transport of sediments also contributed to development and maintenance of the Mammoth Steppe. Local areas where aeolian sediment activity persists today such as active dune fields and loessal soils share several characteristics with the mammoth steppe such as the

Contamination of agricultural lands by polycyclic aromatic hydrocarbons (Tver region, Russia)

NASA Astrophysics Data System (ADS)

Zhidkin, Andrey; Koshovskii, Timur; Gennadiev, Alexander

2016-04-01

It is important to study sources and concentrations of polycyclic aromatic hydrocarbons (PAHs) in the agriculture soils within areas without intensive contaminations. Our studied object was soil and snow cover in the taiga zone (Tver region, Russia). A total of 52 surface (0-30 cm) and 31 subsurface (30-50 cm) soil samples, and 13 snow samples were collected in 35 soil pits, located in forest, crop and layland soils. Studied concentrations of the following 11 individual compounds: two-ring compounds (diphenyl and naphthalene homologues); three-ring compounds (fluorene, phenanthrene, anthracene); four-ring compounds (chrysene, pyrene, tetraphene); five-ring compounds (perylene, benzo[a]pyrene); and six-ring compounds (benzo[ghi]perylene). Analyses made by specrtofluorometry method at the temperature of liquid nitrogen. The total concentrations of all PAHs in soil samples ranged from 9 to 770 ng*g-1 with a median of 96 ng*g-1. The sum of high molecular weight PAHs was significantly lower than the sum of low molecular weight PAHs in the studied soils. The phenanthrene concentration was highest and ranged from 1.2 to 720 ng*g-1 (medium 72 ng*g-1). Compared PAHs reserves in snow cover (μg*m-2) with the reserves in topsoil layer (μg*m-2 in the upper 30 cm). Low molecular weight PAHs (fluorene, phenanthrene, diphenyl, naphthalene) reserves in snow was less than 20% from the reserves in the soil surface layer. High molecular weight PAHs (benzo[a]pyrene, chrysene, perylene, pyrene and tetraphene) reserves in snow was about 50-70% from the reserves in soil surface layer. High molecular weight PAHs (benzo[ghi]perylene and anthracene) reserves in snow was more than in topsoil. PAHs vertical distribution in soil profiles was statistically examined. The total concentration of all PAHs decreased with depth in all studied forest soils. In the arable soils was no significant trend in domination of PAHs total concentrations in the plowing and subsoil layers. The ratio of topsoil

Climate warming impacts on boreal landscape net CO2 exchange

NASA Astrophysics Data System (ADS)

Helbig, Manuel; Kljun, Natascha; E Chasmer, Laura; Desai, Ankur R.; Quinton, William L.; Sonnentag, Oliver

2017-04-01

In boreal peatlands of the North American sporadic permafrost zone, climate change causes permafrost thaw and induces changes in vegetation composition and structure. Boreal landscape net carbon dioxide (CO2) fluxes in these regions will thus be modified directly through the changes in the meteorological forcing of ecosystem processes and indirectly through changes in landscape functioning associated with thaw-induced land cover changes. How the combined effects alter net ecosystem CO2 exchange of these landscapes (NEELAND), resulting from changes in gross primary productivity (GPP) and ecosystem respiration (ER), remains unknown. Here, we quantify indirect land cover and direct climate change impacts on NEELAND for a boreal forest-wetland landscape in the organic-rich Taiga Plains of northwestern Canada. Using 1.5 years of nested eddy covariance flux tower measurements, we observe both larger GPP and ER at the landscape-level (50% forested permafrost plateaus & 50% permafrost-free wetlands) compared to the wetland-level (100% permafrost-free wetland). However, the resulting annual NEELAND (-20±6 g C m-2) was similar to NEE of the wetland (-24±8 g C m-2). Indirect thaw-induced wetland expansion effects thus appear to have negligible effects on NEELAND. In contrast, we find larger direct climate change impacts when modeling end-of-the-21st-century NEELAND (2091-2100) using downscaled air temperature and incoming shortwave radiation projections. Modeled GPP indicates large spring and fall increases due to reduced temperature-limitation. At the same time, light-limitation of GPP becomes more frequent in fall. The projected warmer air temperatures increase ER year-round in the absence of moisture stress. As a result, larger net CO2 uptake is projected for the shoulder seasons while the peak growing season net CO2 uptake declines. The modeled annual NEELAND is projected to decline by 25±15 g C m-2 for a moderate (RCP 4.5) and 103±37 g C m-2 for a high warming

Assessment of chemical element migration in soil-plant complex of Urov endemic localities of East Transbaikalia

NASA Astrophysics Data System (ADS)

Vadim V., Ermakov; Valentina, Danilova; Sabsbakhor, Khushvakhtova; Aklexander, Degtyarev; Sergey, Tyutikov; Victor, Berezkin; Elena, Karpova

2014-05-01

The comparative evaluation of the levels of biologically active chemical elements and their migration in the soil-plant complex of two Urov endemic locations in East Transbaikalia (Zolinsky and Uryumkansky) and background areas (Western Baikal region and the western area of the Trans-Baikal region) was conducted. The predominant soil-forming rocks in East Transbaikalia are weathering products of Proterozoic carbonated granitoids PR2. The surface rocks consist from granite, granodiorite, diorite quartz diorite, gabbro, norite, gabbro-norite and other. Soils - mountain and cryogenic meadow forests, mountain permafrost taiga podzolised, meadow alluvial, peaty meadow [2]. The paludification of narrow valleys and thermokarst phenomena are typical in Urov endemic localities. It reflects on the spotted of soil and differentiation of chemical composition of soils and plants. Most of the chemical elements in soils were determined by means of X-ray fluorescence, and trace elements in soils and plants - by atomic absorption spectrometry. The selenium content was measured by spectrofluorimetric method [3]. The research processed by methods of variation statistics. It was found that the soils of two locations of the Urov subregion of the biosphere were more enriched with iron, barium, calcium, uranium, thorium, phosphorus, and to a lesser extent strontium compared to background soils. The ratio of Ca: P was significantly higher in the soil of background areas, and Ca: Sr, on the contrary, in endemic soils. In assessing the migration of trace elements in soil-plant complex by means of the total content of trace elements and biological absorption coefficient found a marked accumulation by plants manganese, chromium, arsenic and weak plants accumulation of cobalt and nickel. Soil landscape is not much different in content of selenium, but its migration in plants was reduced in places of spread of Urov disease [1]. The concentrators of cadmium (leaves of different species of willow

Biogeochemical Process Comparison of the Five USGS Water, Energy, and Biogeochemical Budget (WEBB) Sites

NASA Astrophysics Data System (ADS)

Shanley, J. B.; Peters, N. E.; Aulenbach, B. T.; Blum, A. E.; Campbell, D. H.; Clow, D. W.; Larsen, M. C.; Mast, M. A.; Stallard, R. F.; Troester, J. W.; Walker, J. F.; Webb, R. M.; White, A. F.

2001-12-01

Input - output budgets (in wet deposition and streamwater) have been constructed for water and major solutes at the five USGS Water, Energy, and Biogeochemical Budget (WEBB) sites for the period 1992-97 (Peters et al., 2000). In this poster we interpret the net chemical fluxes to identify the controlling biogeochemical processes, as influenced by the strong physical and biological contrasts (climate, geology, physiography, and vegetation types) in the five diverse environments. The five sites are: Allequash Creek, Wisconsin (low-relief humid continental forest); Andrews Creek, Colorado (cold alpine, taiga/tundra, and subalpine boreal forest); Icacos River, Puerto Rico (lower montane, wet tropical forest); Panola Mountain, Georgia (humid subtropical piedmont forest); and Sleepers River, Vermont (humid northern hardwood forest). Base cations and Si produced by chemical weathering displayed a net export at each site. The magnitude and stoichiometry of export reflects mineralogy, climate (temperature and rainfall), and water residence time in the subsurface. The lowest and highest mass export generally was for Andrews Creek and Icacos River, respectively, consistent with their extreme mean annual temperatures (0/degC in Colorado to 21/degC in Puerto Rico) and the limited residence time of meltwater at Andrews Creek. Calcite in bedrock at the three coldest watersheds caused somewhat higher relative export of Ca, especially at Sleepers River where calcite weathering is a dominant control on stream chemistry. In contrast, the high Mg content of the volcaniclastic rocks at Icacos River and glacial deposits at Allequash Creek caused disproportionately high Mg export relative to the other sites. Relatively high Na export at Panola Mountain and K export at Sleepers River are probably caused by plagioclase and biotite weathering, respectively. SO4 is retained at the two warmest sites, Panola Mountain and Icacos River. SO4 adsorption is known to limit SO4- export in highly

Extensive survey of terrestrial organic carbon in surface sediments of the East Siberian Sea

NASA Astrophysics Data System (ADS)

Vonk, Jorien; Gustafsson, Örjan; Alling, Vanja; Sánchez-García, Laura; van Dongen, Bart; Andersson, Per; Dudarev, Oleg; Semiletov, Igor; Eglinton, Tim

2010-05-01

The East Siberian Sea (ESS) is the largest and shallowest continental shelf sea of the Arctic Ocean, yet it is the least explored. The perenially frozen tundra and taiga of the circum-Arctic coastal area holds approximately half of the global belowground carbon pool. Significant amounts of terrestrial organic carbon (terrOC) are exported with the Great Siberian Arctic rivers to the shelf seas. In addition, the carbon-rich, ice-bound Yedoma coasts in East Siberia release significant amounts of Pleistocene carbon through thermal degradation and coastal erosion. The fate of these large-scale releases of terrOC in the East Siberian Shelf Sea is still poorly understood. The urgency of this research is accentuated by the fact that the East-Siberian Arctic landmass is experiencing the strongest climate warming on Earth, with a great potential for various carbon-climate feedback links. During the International Siberian Shelf Study 2008 (ISSS-08), a 50-day research expedition onboard the Russian vessel Yakob Smirnitskiy in late summer 2008, we obtained surface sediments from over 60 ESS locations. The data obtained after bulk analyses of these sediments are combined with results obtained from previous ESS campaigns in 2003 and 2004 to facilitate a comprehensive investigation of the ESS surface sediment composition. Sedimentary OC contents were between 0.13 and 3.7% (median 1.02%, interquartile range 0.563) with the highest values near the Indigirka and Kolyma river mouths and in the Long Strait. Stable carbon isotope values were in the range of -27.4 to -21.2 per mill (median -25.3 per mill, interquartile range 2.04), with more depleted values close to the coast. A clear transition was observed east of 170° E with more enriched values, signalling a regime shift with stronger influence of the Pacific Ocean. The terrOC fraction in the surface sediments was estimated from the 13C data to be on average 70% for ESS as a whole, with maximal values of 90-100% (along most of the

[Estimating survival of thrushes: modeling capture-recapture probabilities].

PubMed

Burskiî, O V

2011-01-01

The stochastic modeling technique serves as a way to correctly separate "return rate" of marked animals into survival rate (phi) and capture probability (p). The method can readily be used with the program MARK freely distributed through Internet (Cooch, White, 2009). Input data for the program consist of "capture histories" of marked animals--strings of units and zeros indicating presence or absence of the individual among captures (or sightings) along the set of consequent recapture occasions (e.g., years). Probability of any history is a product of binomial probabilities phi, p or their complements (1 - phi) and (1 - p) for each year of observation over the individual. Assigning certain values to parameters phi and p, one can predict the composition of all individual histories in the sample and assess the likelihood of the prediction. The survival parameters for different occasions and cohorts of individuals can be set either equal or different, as well as recapture parameters can be set in different ways. There is a possibility to constraint the parameters, according to the hypothesis being tested, in the form of a specific model. Within the specified constraints, the program searches for parameter values that describe the observed composition of histories with the maximum likelihood. It computes the parameter estimates along with confidence limits and the overall model likelihood. There is a set of tools for testing the model goodness-of-fit under assumption of equality of survival rates among individuals and independence of their fates. Other tools offer a proper selection among a possible variety of models, providing the best parity between details and precision in describing reality. The method was applied to 20-yr recapture and resighting data series on 4 thrush species (genera Turdus, Zoothera) breeding in the Yenisei River floodplain within the middle taiga subzone. The capture probabilities were quite independent of observational efforts fluctuations

The Holocene environmental history of the Verkhoyansk Mountains region (northeastern Siberia, Russia) reconstructed from high-resolution pollen data

NASA Astrophysics Data System (ADS)

Müller, S.; Tarasov, P. E.; Andreev, A. A.; Diekmann, B.

2009-04-01

percentages decreased, suggesting strengthening of the steppe communities associated with the cold and dry Younger Dryas Stadial. However, the pollen data in hand indicate that Younger Dryas climate was less severe than the climate during the earlier interval from 15 to 13.5 kyr BP. The onset of the Holocene is marked in the pollen record by the highest values of shrub and lowest values of herbaceous taxa, suggesting a return of warmer and wetter conditions after 11.4 kyr BP. Percentages of tree taxa increase gradually and reach maximum values after 7 kyr BP, reflecting the spread of boreal cold deciduous and taiga forests in the region. An interval between 7 and 2 kyr BP is noticeable for the highest percentages of Scots pine (Pinus subgen. Diploxylon), spruce (Picea) and fir (Abies) pollen, indicating mid-Holocene spread of boreal forest communities in response to climate amelioration and degradation of the permafrost layer.

The agricultural features of Nizhegorodskaya gubernia (province) in the XIX century

NASA Astrophysics Data System (ADS)

Kirillova, Vasilisa

2017-04-01

gubernia is located in three agro-climatic areas: (№9) European Southern taiga, sod-podzolic (humus soils of Opol'e), rye, barley, oat, potato and forage (corn silage), (number 11) North-steppe (ETP), gray forest soils with patches of chernozems, winter-wheat-rye, barley, oat, potato with corn silage, (№12) forest-steppe (ETP), leached and podzolized chernozems with gray forest soils , winter-wheat-rye, barley, oat, potato with sugar beet and corn for silage. Analysis of digitized information on cultivated crops of Nizhegorodskaya gubernia in the XIX century and agro-climatic characteristics of areas has shown that the list of selected crops in general corresponds to the recommendations by present-day scientists, but has its own characteristics. In reporting materials there is no information about the cultivation of crops such as winter wheat, sugar beet and corn. Potatoes and barley are cultivated in small quantities, their place is taken lentil, millet and spelt, which in today's recommendations are not mentioned.

Perspectives on Fire Research Collaboration in Siberia: What Have We Learned; Why Does It Matter; and Where Do We Go from Here?

NASA Astrophysics Data System (ADS)

Conard, S. G.

2010-12-01

My first experience of the vast taiga forests of Russia, and my first chance to meet and work with Russian fire researchers, was at a 1993 conference and field experiment planned jointly by Johann G. Goldammer from Germany and Valentin V. Furyaev from Russia. This meeting was the beginning of a long and fruitful collaboration among US, Canadian, and Russian fire scientists. We all became increasingly aware of the global signifiance of the circumpolar boreal zone, and of the need for better information on the extent and effects of boreal fires. Wildfires are the dominant disturbance regime in the Russian boreal zone, burning 10 to 20 million hectares per year. These fires are a significant source of CO2 and other greenhouse gases and aerosols. Our research team published some of the first remote-sensing based estimates of the extent of fire in Russia and of the potential variability in emissions that could result from different burning conditions. Through a series of 20 prescribed burns we were able to mimic a wide range of burning conditions and obtain information on the impacts on soils, vegetation, and fuel consumption. Based on these experimental fires, we have modeled the effects of weather and fuels on fuel consumption and other factors, and related fire characteristics to emissions, carbon stocks, and soil and vegetation processes. For the past 10 years, we have focused on the ecosystem effects of fires of varying severity in the Scots pine and mixed larch forests of central Siberia, on improved remote-sensing based estimates of burned area and fire effects, and on relating fire weather indices to fire potential and fuel consumption. Logging is an increasingly important disturbance in Russia’s forests, and logged sites, with their high fuel loads seem particularly susceptible to fire. We are currently studying interactions between logging and fire, with an emphasis on the differences in fuel consumption, emissions, and carbon stocks when fires burn in

Holocene pollen and sediment record from the tangle lakes area, central Alaska

USGS Publications Warehouse

Ager, Thomas A.; Sims, John D.

1981-01-01

trees. In this case, improved moisture conditions may have promoted spruce growth and reproduction in spite of somewhat cooler temperatures.Previous pollen records from Alaska suggest that Artemisia pollen contributed little to the pollen rain of most taiga and tundra sites during Holocene time. The pollen record from Tangle Lakes, however shows rather high percentages (7–13 percent) of Artemisia deposited during the approximate time interval 4700 to 3500 years B.P. Local habitats that have well‐drained soils derived from glacial deposits support patches of Artemisia telesii and other Artemisia species. These local habitats may account for the source of Artemisiapollen deposited in the Tangle Lakes area during Holocene time.

The Relationship of Forest Fires Detected by MODIS and SRTM Derived Topographic Features in Central Siberia

NASA Technical Reports Server (NTRS)

Ranson, Jon K.; Kovacs, Katalin; Kharuk, Viatcheslav; Burke, Erin

2006-01-01

Fires are a common occurrence in the Siberian boreal forest. The MOD14 Thermal anomalies product of the Terra MODIS Moderate Resolution Spectroradiometer) product set is designed to detect thermal anomalies (i.e. hotspots or fires) on the Earth's surface. Recent field studies showed a dependence of fire occurrence on topography. In this study MODIS thermal anomaly data and SRTM topography data were merged and analyzed to evaluate if forest fires are more likely to occur at certain combinations of elevation, slope and aspect. Using the satellite data over a large area can lead to better understanding how topography and forest fires are related. The study area covers a 2.5 Million krn(exp 2) portion of the Central Siberian southern taiga from 72 deg to 110 deg East and from 50 deg to 60 deg North. About 57% of the study area is forested and 80% of the forest grows between 200 and 1000 m. Forests with pine (Pinus sylvestris), larch (Larix sibirica, L. gmelinii), Siberian pine (Pinus sibirica), spruce (Picea obovata.) and fir (Abies sibirica) cover most of the landscape. Deciduous stands with birch (Betula pendula, B. pubescens) and aspen (Populus tremula) cover the areas of lower elevation in this region. The climate of this area is distinctly continental with long, cold winters and short hot summers. The tree line in this part of the world is around 1500 m in elevation with alpine tundra, snow and ice fields and rock outcrops extending up to over 3800 m. A 500 m resolution landcover map was developed using 2001 MODIS MOD13 Normalized Vegetation Index (NDVI) and Middle Infrared (MIR) products for seven 16-day periods. The classification accuracy was over 87%. The SRTM version 2 data, which is distributed in 1 degree by 1 degree tiles were mosaiced using the ENVI software. In this study, only those MODIS pixels were used that were flagged as "nominal or high confidence fire" by the MODIS fire product team. Using MODIS data from the years 2000 to 2005 along with the

In situ chemical sensing for hydrothermal plume mapping and modeling

NASA Astrophysics Data System (ADS)

Fukuba, T.; Kusunoki, T.; Maeda, Y.; Shitashima, K.; Kyo, M.; Fujii, T.; Noguchi, T.; Sunamura, M.

2012-12-01

Detection, monitoring, and mapping of biogeochemical anomalies in seawater such as temperature, salinity, turbidity, oxidation-reduction potential, and pH are essential missions to explore undiscovered hydrothermal sites and to understand distribution and behavior of hydrothermal plumes. Utilization of reliable and useful in situ sensors has been widely accepted as a promised approach to realize a spatiotemporally resolved mapping of anomalies without water sampling operations. Due to remarkable progresses of sensor technologies and its relatives, a number of highly miniaturized and robust chemical sensors have been proposed and developed. We have been developed, evaluated, and operated a compact ISFET (Ion-Sensitive Field-Effect Transistor)-based chemical sensors for ocean environmental sensing purposes. An ISFET has advantages against conventional glass-based electrodes on its faster response, robustness, and potential on miniaturization, and thus variety of chemical sensors has been already on the market. In this study, ISFET-based standalone pH sensors with a solid-state Cl-ISE as a reference electrode were mounted on various platforms and operated to monitor the pH anomalies in deep-sea environment at the Kairei, Edmond, and surrounding hydrothermal sites in the southern Central Indian Ridge area during KH10-06 scientific cruise (Nov. 2010), supported by project TAIGA (Trans-crustal Advection and In situ biogeochemical processes of Global sub-seafloor Aquifer). Up to three pH sensors were mounted on a wire-lined CTD/RMS (Rosette Multiple Sampler), dredge sampler, a series of MTD plankton nets, and VMPS (Vertical Multiple-operating Plankton Sampler). A standalone temperature sensor was bundled and operated with the pH sensor when they were mounted on the dredge sampler, MTD plankton nets, and VMPS. An AUV equipped with the pH sensor was also operated for hydrothermal activity survey operations. As a result of Tow-Yo intersect operations of the CTD

The biome reconstruction approach as a tool for interpretation of past vegetation and climate changes: application to modern and fossil pollen data from Lake El'gygytgyn, Far East Russian Arctic

NASA Astrophysics Data System (ADS)

Tarasov, P. E.; Andreev, A. A.; Anderson, P. M.; Lozhkin, A. V.; Haltia, E.; Nowaczyk, N. R.; Wennrich, V.; Brigham-Grette, J.; Melles, M.

2013-06-01

The modern and fossil pollen data obtained under the framework of the multi-disciplinary international "El'gygytgyn Drilling Project" represent a unique archive that allows the testing of a range of pollen-based reconstruction approaches and the deciphering of changes in the regional vegetation and climate since ~3.58 Ma. In the current study we provide details of the biome reconstruction method applied to the late Pliocene and Quaternary pollen records from Lake El'gygytgyn. All terrestrial pollen taxa identified in the spectra from Lake El'gygytgyn were assigned to major vegetation types (biomes), which today occur near the lake and in the broader region of eastern and northern Asia and, thus, could potentially have been present in this region during the past. When applied to the modern surface pollen spectra from the lake, the method shows a dominance of the tundra biome that currently characterizes the Lake El'gygytgyn area. When applied to the pollen spectra from the middle Pleistocene to present, the method suggests (1) a predominance of tundra during the Holocene, (2) a short interval during the marine isotope stage (MIS) 5.5 interglacial distinguished by cold deciduous forest, and (3) a long phase of taiga dominance during MIS 31 and, particularly, MIS 11.3. These two latter interglacials seem to be some of the longest and warmest intervals within the past million years. During the late Pliocene-early Pleistocene interval (i.e., ~3.562-2.200 Ma), there is good correspondence between the millennial-scale vegetation changes documented in the Lake El'gygytgyn record and the alternation of cold and warm marine isotope stages, which reflect changes in the global ice volume and sea level. The biome reconstruction demonstrates changes in the regional vegetation which suggest a step-like transition from generally warmer/wetter environments of the earlier (i.e., Pliocene) interval towards colder/drier environments of the Pleistocene. The reconstruction of most of

Evaluating Evapotranspiration of Pine Forest, Switchgrass, and Pine- Switchgrass Intercroppings using Remote Sensing and Ground-based Methods

NASA Astrophysics Data System (ADS)

Amatya, D. M.; Panda, S.; Chescheir, G. M.; Nettles, J. E.; Appelboom, T.; Skaggs, R. W.

2011-12-01

imageries of vegetation and soils will be used. IDRISI Taiga software will be used for the indices development. The forested vegetation health will be correlated to the leaf chlorophyll content for determining the vegetation health with a subsequent derivation of available plant water for radiation. Models will be developed to correlate the plant and soil available water to different vegetation indices. Correlation models will also be developed to obtain information on climatic parameters like surface air temperature, net radiation, albedo, soil moisture content, and stomatal water availability from Landsat imageries. On-site weather parameters used for the PET estimates will be combined with other vegetation parameters like leaf area index (LAI) obtained using LIDAR data and NAIP orthophotos of different seasons. That will also help detect the upper and understory vegetation. The LIDAR data will be processed to obtain the volume of vegetation to correctly estimate the total ET for each treatment.

Change of physical and chemical parameters of fulvic acids at different pH of the system

NASA Astrophysics Data System (ADS)

Dinu, Marina; Kremleva, Tatyana

2017-04-01

Organic substances of humic nature significantly change physicochemical properties at different pH of natural waters. As a consequence, a large number of consecutive and parallel reactions in the structure of organic polymers, and reacting with inorganic anions. The main indicators of changes in the properties of organic acids in natural systems are changes in their IR spectra, changes in the colloid stability (the zeta potential) as well as in the molecular weight and emission spectra (fluorescence emission spectra). The aim of our study was to evaluate of changing in physical and chemical properties of the fulvic acid from soil/water samples in the natural areas of European Russia and Western Siberia (the steppe and the northern taiga zones) at different pH (from 8 to 1.5). Changes in absorption bands of fulvic acid caused by both COOH groups and amino groups with varying degrees of protonation were found. Consequently, we can assume that in an electric field fulvic acid change the sign of their charge at depending on pH. During the lowering of the pH intensity of C-O bands generally decreases, while in the region 1590 cm-1 disappears. In turn, the band at 1700 cm-1 is the most intense; it could mean a complete protonation of the carboxyl groups. According to our data, the values of zeta potential changes depending on pH of the system. The zeta potential becomes more negative with increasing pH and it may be due to ionization of oxygen groups of fulvic acid. For the colloidal polymer systems the value of the zeta potential is strongly negative (less than -20 mV) and strongly positive (over 20 mV) characterize the system as the most stable. Our experimental data for the study of the zeta potential of fulvic acids extracted from the soils and waters of different climatic zones show zonal influence of the qualitative characteristics of organic substances on the surface charge of the high-molecular micelle of fulvic acids. It was found that fulvic acids extracted

Soil greenhouse gases fluxes in forest - fallow succession at the Central Forest Reserve in European Russia

NASA Astrophysics Data System (ADS)

Komarova, Tatiana; Vasenev, Ivan

2017-04-01

One of the principal factors influencing the current level of the greenhouse fluxes are land-use changes, including the forest restoration in fallow lands, which is widespread at the Central Region of Russia. The comprehensive environmental studies of soil greenhouse fluxes have been done in comparable sites with different stages of the forest-fallow successions in the southern part of the Central Forest Reserve with spruce domination in the mature forest - representative southern-taiga ecosystems. Seasonal and diurnal dynamics CO2 fluxes measurements were carried out in situ using a mobile gas analyzer Li-820 with soil exposure chambers and parallel observation of air temperature, soil temperature and moisture. Also, every ten days the soil air has been sampled in the vials for further CO2, CH4 and N2O flux measurements by the stationary gas chromatograph. Within forest-fallow successions there are shown the litter gradual development, humus-accumulative horizon differentiation, soil acidity and bulk density increasing. At the same time there is enough obvious in the down part of past-arable horizon gradual restoration of the podzolic horizon. The monitoring results have shown the essential decreasing of soil CO2 fluxes (in 2 times) in frame of successions. The maximum CO2 fluxes have been fixed in July with optimal soil temperature/moisture ratio. In the middle of July the maximum CO2 emission is observed in fallow grassland (34,1 g CO2 / m2day), that is almost in 2-times more than in spruce-forest after fallow stage of 120-150 years. It is important that soil CO2 fluxes essentially increase with soil temperature rise (with up to R = 0,75) and drop soil moisture (with up to R = - 0,66). During the day, the most intense soil CO2 fluxes have been observed from case of 12:00 to 18:00. The maximum CO2 flux has been recorded at 15:00 in the fallow grassland (23 g CO2 / m2 day). In the forest-fallow stage of 10-15 years the maximum soil CO2 flux observed at 12 hours

Microrelief and vegetation as the factors of spatial redistribution of nutrients in the soils of forest ecosystems

NASA Astrophysics Data System (ADS)

Chernitsova, Olga; Krechetov, Pavel

2017-04-01

The study is aimed at the identifying factors and mechanisms controlling the redistribution of nutrients in the profile of sod-podzolic soils (Umbric Albeluvisols Abruptic in WRB, 2006). The data of chemical analyzes of soil samples of soddy-pale-podzolic soils under mixed coniferous-deciduous forests, picked from the genetic horizons of 28 soil profiles up to the depth of 120-150 cm in the key area with a polygonal-block microrelief (58.39°N, 56.52°E) were used. Soil profiles were placed at the key area considering vegetation and microrelief. Samples were analyzed for humus content, available forms of N, P, K, Ca, Mg and soil texture. Published data on the capacity and the structure of biogeochemical cycling in forest phytocenoses of different ages in the southern taiga were summarized. Field sketches were used for the construction of the digital elevation model of the key area and for plotting the vegetation map showing the crowns' projections of trees and shrubs of different species. Using spatial interpolation in GIS, series of schematic maps were created that characterize the depth of the lower boundary of genetic horizons and their thickness, as well as the texture of the different soil horizons, humus content and distribution of nutrients at different depths. These schematic maps were analyzed for patterns of radial and lateral differentiation of all examined features. Pronounced textural differentiation of soils of micro-elevations and poor textural differentiation of soil of micro-depressions are revealed. It is shown that in the soils with the positions from micro-elevations through flat surfaces to micro-depressions the humus content in the upper layers (horizon A) increases 1.6-1.7 times, the content of nitrogen ‒ 1.4-1.5, phosphorus ‒ 2.6 8.4, calcium and magnesium cations ‒ 1.8-2.9 times. This differentiation in nutrients' content is coming along with the settlement of more demanding to soil fertility plants in micro-depressions. Also the

Reconstruction of Landscape Evolution Zones (LEZ) from laminated Eifel maar sediments of the last 60 000 years

NASA Astrophysics Data System (ADS)

Sirocko, Frank

2016-04-01

500 to 49 000 b2k was characterized by a boreal forest with high abundance of pine, birch, and also spruce during the interstadial events. Abundant charcoal fragments indicate that this taiga was under frequent drought stress. The most unexpected finding, but corroborated by all maar records studied, are the abundant thermophilous tree taxa characterizing the time interval 49 000 - 55 000 b2k, representing LEZ 8. The Greenland interstadials 13 and 14 were apparently the warmest part of MIS 3. The proceeding LEZ 9 from 55 000 - 60 000 b2k is also dominated by spruce, but thermophilous trees were only very rare. A continuously warm GI 13/14 appears plausible, because summer insolation was higher in the early MIS 3 than today, ice cover was low in Scandinavia and sea-surface temperatures of the North Atlantic were almost comparable to modern values during GI-14.

Global assessment of soil organic carbon stocks and spatial distribution of histosols: the Machine Learning approach

NASA Astrophysics Data System (ADS)

Hengl, Tomislav

2016-04-01

tools. Results of model fitting using the R packages nnet, randomForest and the h2o software (machine learning functions) show that significant models can be fitted for soil classes, bulk density (R-square 0.76), soil organic carbon (R-square 0.62) and coarse fragments (R-square 0.59). Consequently, we were able to estimate soil organic carbon stock for majority of the land mask (excluding permanent ice) and detect patches of landscape containing mainly organic soils (peat and similar). Our results confirm that hotspots of soil organic carbon in Tropics are peatlands in Indonesia, north of Peru, west Amazon and Congo river basin. Majority of world soil organic carbon stock is likely in the Northern latitudes (tundra and taiga of the north). Distribution of histosols seems to be mainly controlled by climatic conditions (especially temperature regime and water vapor) and hydrologic position in the landscape. Predicted distributions of organic soils (probability of occurrence) and total soil organic carbon stock at resolutions of 1 km and 250 m are available via the SoilGrids.org project homepage.

Environmental Studies in the Boreal Forest Zone: Summer IPY Institute at Central Boreal Forest Reserve, Fedorovskoe, Tver area, Russia (14-28 August, 2007)

NASA Astrophysics Data System (ADS)

Sparrow, E. B.; Kurbatova, Y.; Groisman, P.; Alexeev, V.

2007-12-01

Reserve were arranged to highlight various aspects of wetland studies and management in the European taiga environment. As part of the GLOBE (Global Learning and Observations to Benefit the Environment) IPY "Seasons and Biomes" project led by Dr. Elena Sparrow, the K-12 teachers were instructed in and practiced existing GLOBE protocols as well as new protocols created specifically for the Seasons and Biomes project to study interannual variability of seasons in their own biomes. These teachers will in turn engage their students in Earth System scientific research as a way of teaching and learning science as well as involving them in the IPY. Support for the Summer Institute was provided by many institutions and organizations from the United States (IARC, NASA, NSF, University of Maryland, GLOBE USA, and Hydrology Science and Services Corporation), Russia (Central Biosphere Forest Reserve, A.N. Severtsov Institute for Ecology and Evolution of the Russian Academy of Sciences, Southern Federal University, Russian Foundation for Basic Research, GLOBE Russia, and non-profit organization "Transparent World"), Japan (National Institute for Environmental Studies), China (Beijing Normal University), Germany (Friedrich-Schiller-University) and the Circumpolar North (University of the Arctic).

The Batagay permafrost mega thaw slump: an environmental archive of the Late Pleistocene continental climate

NASA Astrophysics Data System (ADS)

Ashastina, Kseniia; Kienast, Frank; Römermann, Christine; Kuzmina, Svetlana; Diekmann, Bernhard; Schirrmeister, Lutz

2017-04-01

Palaeoenvironmental data preserved in permafrost contribute in our understanding of climate changes and their influence on the biocenoses during the Late Quaternary. Here we present cryolithological and palaeoecological results of studies carried out on a newly described permafrost exposure near Batagay about 50 km from Verkhoyansk, Sakha Republic, Russia, the town with the most continental climate recorded in the northern hemisphere. According to Günther et al. (2015), this unique exposure is the biggest mega thaw slump measured so far with the dimensions 800 m wide and 73 m deep. Only sparse data on the exposure are so far published in few articles (Novgorodov et al., 2013; Kunitsky et al., 2013; Ashastina et al., in press; Murton et al., 2016). The site is situated inWest Beringia, the Late Quaternary landmasscovered by tundra steppe and inhabited by diverse mega herbivores. We analyzed sedimentological data, plant macro- and micro-fossils together with insect remains in order to reconstruct the changes in the biome. The temporal frame for the accumulation of the sequence is provided by radiocarbon and optical stimulated luminescence dating, according to which the formation of the sequence started in the late Middle Quaternary. The features of permafrost accumulation and sedimentation give us an opportunity to propose the landscape changes responding to the climatic pulses of Pleistocene at this particular place. The shifts in vegetation from taiga to steppe associations are in a line with stadial and intersadial events. We propose a scheme of permafrost state and vegetation changes and merge it with climate variation during Late Quaternary. Ashastina, K., Schirrmeister, L., Fuchs, M., Kienast, F.: Pleistocene climate characteristics in the most continental part of the northern hemisphere: insights from cryolithological features of the Batagay mega thaw slump in the Siberian Yana Highlands. Climate of the Past, in press. doi: 10.5194/cp-2016-84. Günther, F

Location of space debris by infrasound

NASA Astrophysics Data System (ADS)

Asming, Vladimir; Vinogradov, Yuri

2013-04-01

After an exhausted stage has separated from a rocket it comes back to the dense atmosphere. It burns and divides into many pieces moving separately. Ballisticians can calculate an approximate trace of a falling stage and outline a supposed area where the debris can fall (target ellipse). Such ellipses are usually rather big in sizes (something like 60 x 100 km). For safety reasons all local inhabitants should be evacuated from a target area during rocket's launch. One of problems is that the ballistician can not compute the traces and areas exactly. There were many cases when debris had fallen outside the areas. Rescue teams must check such cases to make changes in rockets. The largest pieces can contain remains of toxic rocket fuel and therefore must be found and deactivated. That is why the problem of debris location is of significant importance for overland fall areas. It is more or less solved in Kazakhstan where large fragments of 1st stages can be seen in the Steppe but it is very difficult to find fragments of 2nd stages in Altai, Tomsk region and Komi republic (taiga, mountains, swamps). The rocket debris produces strong infrasonic shock waves during their reentry. Since 2009 the Kola Branch of Geophysical Survey of RAS participates in joint project with Khrunichev Space Center concerning with infrasound debris location. We have developed mobile infrasound arrays consisting of 3 microphones, analog-to-digit converter, GPS and notebook. The aperture is about 200 m, deployment time is less than 1 hour. Currently we have 4 such arrays, one of them is wireless and consists of 3 units comprising a microphone, GPS and radio-transmitter. We have made several field measurements by 3 or 4 such arrays placed around target ellipses of falling rocket stages in Kazakhstan ("Soyuz" rocket 1st stage), Altai and Tomsk region ("Proton" rocket 2nd stages). If was found that a typical 2nd stage divides into hundreds of pieces and each one generates a shock wave. This is a

Phytoremediation of disturbed lands in Polar Regions of Russia

NASA Astrophysics Data System (ADS)

Shamsutdinova, Evgeniya

2017-04-01

In the Northern regions the problem of restoration of disturbed lands as a result of anthropogenic activities is particularly acut. A large role for the success of native plants to take hold and re-establish themselves is to allow the natural process to work without human intervention. However observation shows that low reserves of available moisture, poor soil nutrients, exposure to wind and water erosion make impossible of a complete restoration of lands due to natural revegetation. One of the methods used to minimize the effect of these factors is the phytoremediation. Research on the Pelyatinskom gas condensate field in the Taimyr Dolgano-Nenets municipal district revealed the efficacy of biological remediation of awnless brome, wildrye siberian, red fescue and kentucky bluegrass. Geobotanical studies of the tailings fields in Yakutia showed that for the phytoremediation of tailings of alluvial deposits of diamonds slough grass can be successfully used, and on the dumps of coal deposits with a high degree of survival of the willow, poplar, larch, alder stand and pine. Development of technology for remediation of placer gold deposits of the Komsomol mine and Bilibino in Chukotka has shown the effectiveness of sowing common oat, wildrye and larch. The study of the experience of recultivation on objects of the "Transneft-Baltic" in the North-Western Federal district allowed us to select as the recommended mixtures of species: meadow fescue, cocksfoot, timothy grass, white and alsike clover and alfalfa. The multicomponent mixture of red fescue, awnless brome, meadow fescue, timothy grass, couch grass, kentucky bluegrass, beckman's grass were successfully used at the mine of the Bovanenkovo oil and gas condensate field. On the technological grounds of the complex pumping station in the Yamalo-Nenets Autonomous area willows were planted. Pine and willow trees were planted on quarry workings in the Northern taiga of Western Siberia land .Planting of pines has shown

Preliminary Analysis of the efficacy of Artificial neural Network (ANN) and Cellular Automaton (CA) based Land Use Models in Urban Land-Use Planning

NASA Astrophysics Data System (ADS)

Harun, R.

2013-05-01

relative effectiveness of the two models, ANN and CA, in urban planning. The questions that are addressed in this research are: a) What makes ANN models different from CA models?; b) Which model has higher accuracy in predicting future urban land use change?; and c) Are the models effective enough in guiding urban land use policies and strategies? The models that are used for this research are Multilayer Perceptron (MLP) and CA model, available in IDRISI Taiga. Since, the objective is to perform a comparative analysis and draw general inferences irrespective of specific urban policies, the availability of data was given more emphasis over the selection of particular location. Urban area in Massachusetts was chosen to conduct the study due to data availability. Extensive literature review was performed to understand the functionality of the two models. The models were applied to predict future changes and the accuracy assessment was performed using standard matrix. Inferences were drawn about the applicability of the models in urban planning context along with recommendations. This research will not only develop understanding of land use models among urban planners, but also will create an environment of coupled research between planners and modellers.

Environmental assessment of bioenergy technologies application in Russia, including their impact on the balance of greenhouse gases

NASA Astrophysics Data System (ADS)

Andreeva, Irina; Vasenev, Ivan

2017-04-01

into account conditions of the particular type of agricultural landscape, possible changes in the characteristics and structure of land use, direct and indirect effects on the ecosystem components and biodiversity. North-Western, Central and Southern regions of the European part of Russia have great potential to produce biofuels. While there is a clearly expressed zonal agroclimatic potential of growing bio-energy crops (1.5 times increase of PAR in the forest-steppe zone in comparison with the area of the southern taiga) and there is a steady trend of further growth with a parallel increase in the amount of rainfall and the amount of active temperatures for the XXI century forecast. Particular attention should be payed to areas with high population density and industrial production with the possibility of combining the cultivation of oilseed rape for the bio-energy purpose with phytoremediation and soil improving effect of the contaminated and unproductive soils. The increasing potential of atmospheric carbon's temporary binding in the biomass of the bio-energy crops and consequently in the biofuels produced from them can significantly reduce total emissions of greenhouse gases in the conditions of the European part of Russia, but there is the need for more detailed balance calculation for specific soil and climatic conditions and land-use systems.

Deployment of an Ecosystem Warming Prototype at the Fairbanks Permafrost Experiment Station

NASA Astrophysics Data System (ADS)

Wagner, A. M.; Zufelt, J. E.; Wullschleger, S. D.

2010-12-01

at depths below 1.4 m. Permafrost moisture contents range from 26 to 41 percent by mass for the frozen silts which makes this relatively low moisture content permafrost. Vegetation is typical of the Alaskan Interior-subarctic taiga forest with white spruce (Picea glauca [Moench] Voss), and black spruce (P. mariana [Mill] B.S.P) interspersed with lowbush cranberry (Vaccinium oxycoccos L.) and Labrador tea (Ledum groenlandicum Oeder). Feather moss and sphagnum moss are present in the understory. The experimental plot is a hexagonal shaped area (29 by 25 m) where vegetation had previously been removed but has regrown over the last 40-50 years. Soil warming is accomplished by 127 vertically-installed low-energy heating elements installed at spacing of 2.4 m and to a depth of 4 m. Only the lower 1-m is heated to a setpoint +4°C above ambient. The heated area includes a buffer zone resulting in a test area with a diameter of 20 m. This proof-of-concept study will result in improvements to experimental design and thermal modeling ground-truth data as the scientific community plans for possible next-generation climate change experiments in terrestrial permafrost ecosystems.

Carbon balance of the typical grain crop rotation in Moscow region assessed by eddy covariance method

NASA Astrophysics Data System (ADS)

Meshalkina, Joulia; Yaroslavtsev, Alexis; Vassenev, Ivan

2017-04-01

Croplands could have equal or even greater net ecosystem production than several natural ecosystems (Hollinger et al., 2004), so agriculture plays a substantial role in mitigation strategies for the reduction of carbon dioxide emissions. In Central Russia, where agricultural soils carbon loses are 9 time higher than natural (forest's) soils ones (Stolbovoi, 2002), the reduction of carbon dioxide emissions in agroecosystems must be the central focus of the scientific efforts. Although the balance of the CO2 mostly attributed to management practices, limited information exists regarding the crop rotation overall as potential of C sequestration. In this study, we present data on carbon balance of the typical grain crop rotation in Moscow region followed for 4 years by measuring CO2 fluxes by paired eddy covariance stations (EC). The study was conducted at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Two fields of the four-course rotation were studied in 2013-2016. Crop rotation included winter wheat (Triticum sativum L.), barley (Hordeum vulgare L.), potato crop (Solanum tuberosum L.) and cereal-legume mixture (Vicia sativa L. and Avena sativa L.). Crops sowing occurred during the period from mid-April to mid-May depending on weather conditions. Winter wheat was sown in the very beginning of September and the next year it occurred from under the snow in the phase of tillering. White mustard (Sinapis alba) was sown for green manure after harvesting winter wheat in mid of July. Barley was harvested in mid of August, potato crop was harvested in September. Cereal-legume mixture on herbage was collected depending on the weather from early July to mid-August. Carbon uptake (NEE negative values) was registered only for the fields with winter wheat and white

Space Radar Image of Kliuchevskoi, Russia

NASA Technical Reports Server (NTRS)

1994-01-01

This is an X-band seasonal image of the Maly Semlyachik volcano, which is part of the Karymsky volcano group on Kamchatka peninsula, Russia. The image is centered at 54.2 degrees north latitude and 159.6 degrees east longitude. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on April 9, 1994, during the first flight of the radar system, and on September 30, 1994, during the second flight. The image channels have been assigned the following colors: red corresponds to data acquired on April 9; green corresponds to data acquired on September 30; and blue corresponds to the ratio between data from April 9 and September 30, 1994. Kamchatka is twice as large as England, Scotland and Wales combined and is home to approximately 470,000 residents. The region is characterized by a chain of volcanoes stretching 800 kilometers (500 miles) across the countryside. Many of the volcanoes, including the active Maly Semlyachik volcano in this image, have erupted during this century. But the most active period in creating the three characteristic craters of this volcano goes back 20,000, 12,000 and 2,000 years ago. The highest summit of the oldest crater reaches about 1,560 meters (1,650 feet). The radar images reveal the geological structures of craters and lava flows in order to improve scientists' knowledge of these sometimes vigorously active volcanoes. This seasonal composite also highlights the ecological differences that have occurred between April and October 1994. In April the whole area was snow-covered and, at the coast, an ice sheet extended approximately 5 kilometers (3 miles) into the sea. The area shown surrounding the volcano is covered by low vegetation much like scrub. Kamchatka also has extensive forests, which belong to the northern frontier of Taiga, the boreal forest ecosystem. This region plays an important role in the world's carbon cycle. Trees require 60 years to

Soil cover patterns and SOC dynamics impacts on the soil processes, land management and ecosystem services in Central Region of Russia

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Chernikov, Vladimir; Yashin, Ivan; Geraskin, Mikhail; Morev, Dmitriy

2014-05-01

In the Central Region of Russia (CRR) the soil cover patterns usually play the very important role in the soil forming and degradation processes (SFP & SDP) potential and current rates, soil organic carbon (SOC) dynamics and pools, greenhouse gases (GHG) emissions and soluble SOC fluxes that we need take into attention for better assessment of the natural and especially man-changed ecosystems' services and for best land-use practices development. Central Region of Russia is the biggest one in RF according to its population and role in the economy. CRR is characterized by high spatial variability of soil cover due to as original landscape heterogeneity as complicated history of land-use practices during last 700 years. Our long-term researches include the wide zonal-provincial set of representative ecosystems and soil cover patterns with different types and history of land-use (forest, meadow-steppe and agricultural ones) from middle-taiga to steppe zones with different level of continentality. The carried out more than 30-years region- and local-scale researches of representative natural and rural landscapes in Tver', Yaroslavl', Kaluga, Moscow, Vladimir, Saransk (Mordovia), Kursk, Orel, Tambov, Voronezh and Saratov oblasts give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different soil forming and degradation processes rates and soil organic carbon dynamics due to regionally specific soil-geomorphologic features, environmental and dominated microclimate conditions, land-use current practices and history. The validation and ranging of the limiting factors of SFP and SDP develop¬ment, soil carbon dynamics and sequestration potential, ecosystem (agroecosystem) principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of SOC structure analysis, regional and local GIS, soil spatial patterns detail

Reconstruction of Holocene palaeoclimate and environment in the Khatanga region, Russian Arctic

NASA Astrophysics Data System (ADS)

Syrykh, Ludmila; Nazarova, Larisa

2016-04-01

Arctic regions are highly sensitive to changes in temperature and precipitation, and their Late Quaternary environmental history is very important for understanding of present and past climate trends. Though the timing of Holocene climate change is well established for wide parts of the Northern Hemisphere, suitable palaeoenvironmental records are still scarce in the Russian Siberian Arctic. Taimyr Peninsula (74oN, 100oE) is the northernmost part of Russia. Thus, this area is probably one of the most promising regions for the reconstruction of the Late Quaternary environment in dependence on changes in global and regional climate and the atmospheric circulation. (Andreev et al., 2004).The area is characterized by a continental climate with long, severe winters, and short summers. The modern temperatures are about 10-14oC in July, and - 32 to 34oC in January. Annual precipitation ranges from about 300-400 mm at low elevations to about 600-800 mm on the western slopes of the Putorana Plateau (Atlas Arktiki, 1985). The frost-free period is ca. 35 days. Almost all the territory is underlain by continues permafrost. Periglacial landscape is dominated by tundra and taiga vegetation. Aquatic organisms such as chironomids (Insecta: Diptera) are recognized as the best biological indicators for quantifying past changes in air temperature or lake chemistry (Letter et al., 1997; Brooks and Birks, 2000; Battarbee, 2000; Massaferro and Brooks, 2002; Solovieva et al., 2005). Chironomids belong to the most abundant group of fresh-water bottom-dwelling macroinvertebrates. Because of their short life cycle, chironomids quickly adapt to environmental changes and in global scale the distribution and abundance of chironomids are mostly limited by temperature (Walker and Mathewes, 1987; Warwick, 1989; Hann et al., 1992; Walker et al., 1992). Larval head capsules of chironomids preserved in lake sediment as subfossils are abundant, identifiable and serve as indicators of the

The ELSA-Vegetation-Stack: Reconstruction of Landscape Evolution Zones (LEZ) from laminated Eifel maar sediments of the last 60,000 years

NASA Astrophysics Data System (ADS)

Sirocko, F.; Knapp, H.; Dreher, F.; Förster, M. W.; Albert, J.; Brunck, H.; Veres, D.; Dietrich, S.; Zech, M.; Hambach, U.; Röhner, M.; Rudert, S.; Schwibus, K.; Adams, C.; Sigl, P.

2016-07-01

from the Auel dry maar. The main paleobotanical indicators of MIS3 are, however, grass pollen and heliophytes, which indicate a steppe environment with scattered/patchy trees during the interstadials. The stadial phases inferred during LEZ 6 reveal initiation of eolian dust deflation. The change of the early MIS 3 forested landscape to a steppe occurred with the LEZ 7-LEZ 6 transition. This is when modern man spread in central Europe. The principle vegetation change to a steppe at 36,500 b2k must have favoured the spread of horses, an important hunting prey of modern humans. We propose accordingly that the migration of the modern humans into central Europe might have been at least partly driven by climate and associated vegetation change. The LEZ 7 encompassed the time interval 36,500 to 49,000 b2k and was characterized by a boreal forest with high abundance of pine, birch, as well as spruce during the interstadial events. Abundant charcoal fragments indicate that this taiga was under frequent drought stress with regular burning. The most unexpected finding, but corroborated by all our maar records is the dominance of thermophilous tree taxa from 49,000 to 55,000 b2k (LEZ 8). Greenland interstadials 13 and 14 were apparently the warmest of MIS 3 according to the Eifel pollen records. The preceeding LEZ 9 from 55,000 to 60,000 b2k is also dominated by spruce, but thermophilous trees were sparse. A warm early MIS3 appears plausible, because summer insolation (at 60° N) was higher in the early MIS 3 than today, ice cover was low in Scandinavia and sea-surface temperatures of the North Atlantic were almost comparable to modern values during GI-14.

Effects of forest cover changes in European Russia on regional weather conditions: results of numerical experiments with the COSMO-CLM model

NASA Astrophysics Data System (ADS)

Olchev, Alexander; Kuzmina, Ekaterina; Rozinkina, Inna; Nikitin, Mikhail; Rivin, Gdaly S.

2017-04-01

The forests have a significant effect on the climatic system. They capture CO2 from the atmosphere, regulate the surface evaporation and runoff, and influence the radiation and thermal conditions of the land surface. It is obvious, that their influence depends on many different factors including regional climate conditions, land use and vegetation structure, surface topography, etc. The main goal of the study is to assess the possible influence of forest cover changes (under deforestation and/or afforestation) on regional weather conditions in the central part of European Russia using the results of modeling experiments provided by the meso-scale COSMO-CLM model. The need of the study lies in a lack of the experimental and modeling data characterizing the influence of the forest and land-use changes on regional weather conditions in European part of Russia. The forest ecosystems in the study region play a very important biosphere role that is significantly increased in the last decades due to considerable strengthening of anthropogenic activity in the area of European Russia. The area selected for the study is located in the central part of European Russia between 55 and 59N and 28 and 37E. It comprises several geographical zones including dark-coniferous forests of the South-European taiga in the north, the mixed forests in the central part and the broad-leaved forests in the south. The forests within the study area are very heterogeneous. The total area covered by forests according to recent remote sensing data is about 50%. The numerical experiments were provided using the COSMO-CLM model with the spatial resolution 13.2 km. As initial and boundary conditions for the numerical experiments the global reanalysis ERA Interim (with the 6-hour resolution in time and 0.75° × 0.75° in space) were used. The weather conditions were simulated in a continuous cycle for several months for the entire area of European Russia using the results of global reanalysis on

Soil cover patterns influence on the land environmental functions, agroecological quality, land-use and monitoring efficiency in the Central Russia

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Yashin, Ivan; Lukin, Sergey; Valentini, Riccardo

2015-04-01

current practice versions. Well-elaborated monitoring collaboration with the principal natural reserves in south-taiga and forest-steppe zones provides process-based interaction with long-term data on zonal climatic, landscape and soil features necessary to test the process, functional and evaluation models in the specific conditions of each bioclimatic zone. The dominated erosion and dehumification trends have been essentially activated for last 3-4 decades due to hu¬mus negative balance around 0.6-0.7 t ha-1year-1 and connected disaggregation with annual rate between 1 and 25 g/kg for aggregates 10-0.25 mm. "Standard" monitoring objects and regionally generalized data showed characteristic for Chernozems 2-2.5 % humus drop during this period and active processes of CO2 emission and humus eluvial-illuvial profile redistribution too. Forest-steppe Chernozems are usually characterized by higher stability than steppe ones. The ratio between erosive and biological losses in humus stock can be ten¬tatively estimated as fifty-fifty with essential variability within slope landscape. Both these processes have essential impacts on different sets of soil environmental and agroecological functions (including atmospheric air, surface and ground water quality, biodiversity and profitability) that we need to understand and predict. A drop of humus content below threshold values (for different soils between 1.5 and 6%) considerably reduces not only soil environmental regulation functions but also effectiveness of used fertilizers, crop yield quality and possibility of sustainable agricultural land-use. The carried out long-term researches of representative natural, rural and urban landscapes in Tver, Yaroslavl, Vladimir, Moscow, Kaluga, Kursk, Belgorod, Tambov, Voronezh and Saratov regions give us validation and ranging of the limiting factors of the elementary soil cover patterns current features and transformation processes, environmental functions and agroecological quality

Developing a Science-based River Basin Management Plan for the Kharaa River Basin, Mongolia

NASA Astrophysics Data System (ADS)

Karthe, Daniel

2013-04-01

The Kharaa River Basin (KRB), which is located north of Mongolia's capital Ulaanbaatar and south of Lake Baikal, was chosen as a model region for the development and implementation of an integrated water resources management consisting of a monitoring concept, technical measures and a capacity development program (Karthe et al. 2012a). The basin of the Kharaa River covers an area of 14534 km² that is partly mountaineous and largely covered by taiga and steppe. At its outlet, the 362 km Kharaa River has a mean long-term annual discharge of 12.1 m³/s (MoMo Consortium 2009). A highly continental climate results in limited water resources, and rising water consumption coupled with the effects of climate and land use change may in the future exacerbate this water scarcity (Malsy et al. 2012; Karthe et al. 2013). Whereas the environment in the upper part of the catchment is in a relatively pristine state, the mid- and downstream sections of the river are characterized by nearby industry, mining activities and intensive agriculture (Menzel et al. 2011), resulting in declining water quality and ultimately a degradation of aquatic ecosystems (Hofmann et al. 2010; Hartwig et al. 2012). Moreover, it is a problem for the supply of major cities like Darkhan which largely rely on alluvial aquifers containing shallow-depth groundwater (Mun et al. 2008). Currently, there are alarming signs of water quality deterioration. With regard to water provision, a major problem is the poor state of distribution infrastructures which were often built in the 1960s and 70s (Scharaw & Westerhoff 2011). Rather little is currently known about the water quality supplied to end users; the latter is even more dubious in the city's informal ger districts (Karthe et al. 2012b). One important goal of the research and development project "Integrated Water Resources Management in Central Asia: Model Region Mongolia" lies in the implementation of a holistic concept for water resources monitoring and

New views on changing Arctic vegetation

NASA Astrophysics Data System (ADS)

Kennedy, Robert E.

2012-03-01

. Environ. 114 183-98 IPCC 2007 Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change ed Core Writing Team, R K Pachauri and A Reisinger (Geneva: IPCC) Kennedy R E, Yang Z and Cohen W B 2010 Detecting trends in forest disturbance and recovery using yearly Landsat time series: 1. LandTrendr—Temporal segmentation algorithms Remote Sens. Environ. 114 2897-910 Klady R A, Henry G H R and Lemay V 2011 Changes in high Arctic tundra plant reproduction in response to long-term experimental warming Glob. Change Biol. 17 1611-24 Lenihan J M, Bachelet D, Neilson R P and Drapek R 2008 Simulated response of conterminous United States ecosystems to climate change at different levels of fire suppression, CO2 emission rate, and growth response to CO2 Glob. Planet. Change 64 16-25 Masek J G 2001 Stability of boreal forest stands during recent climate change: evidence from Landsat satellite imagery J. Biogeogr. 28 967-76 Myneni R B, Tucker C J, Asrar G and Keeling C D 1998 Interannual variations in satellite-sensed vegetation index data from 1981 to 1991 J. Geophys. Res.—Atmos. 103 6145-60 Pieper S J, Loewen V, Gill M and Johnstone J F 2011 Plant responses to natural and experimental variations in temperature in Alpine Tundra, Southern Yukon, Canada, Arct. Antarct. Alp. Res. 43 442-56 Potapov P V, Turubanova S and Hansen M C 2011 Regionals-scale boreal forest cover and change mapping using Landsat data composites for European Russia Remote Sens. Environ. 115 548-61 Ranson K J, Sun G, Kharuk V I and Kovacs K 2004 Assessing tundra-taiga boundary with multi-sensor satellite data Remote Sens. Environ. 93 283-95 Scheller R M and Mladenoff D J 2005 A spatially interactive simulation of climate change, harvesting, wind, and tree species migration and projected changes to forest composition and biomass in northern Wisconsin, USA Glob. Change Biol. 11 307-21 Seastedt T R, Bowman W D

Disappearance of the last lions and hyenas of Europe in the Late Quaternary - a chain reaction of large mammal prey migration, extinction and human antagonism

NASA Astrophysics Data System (ADS)

Diedrich, Cajus G.

2010-05-01

In the Eemian to Early/Middle Weichselian (Late Pleistocene), when the Scandinavian and Alpine Glaciers were still small, and northern Germany under mammoth steppe to taiga palaoenvironment conditions, Late Quaternary steppe lions were well distributed in northern to central Germany, whereas generally all over Central Europe bones and rarely articulated skeletons were found less at open air but mainly at cave sites (Diedrich 2007a, 2008a-b, 2009a-b, 2010a-c, k, in review a-b; Diedrich and Rathgeber in review). A similar distribution, but more dense, is reported for the Late Quaternary Ice Age spotted hyenas (Diedrich 2005, 2006, 2007b-c, 2008a, c, 2010f-j, in review c-d, Diedrich and Žák 2006). The last lions of northern Europe were thought to have reached into the final Magdalénan (cf. Musil 1980). This can be not concluded with a restudy of the bone material from the Late Magdalenian (V-VI) Teufelsbrücke stone arch site near Saalfeld (Thuringia, Central Germany) and many other Magdalenian stations (open air and caves) in northern to central Germany (Münsterland Bay, Sauerland Karst, Harz Mountain Karst, Thuringian Karst). None of those sites yield remains of final Upper Pleistocene spotted hyenas or steppe lion bones anymore, nor in the few preserved Late Magdalenian mobile art can those be recognized in those regions. The last lion remains seem to reach into the Aurignacian or possibly into the Early Gravettian (early Late Weichselian) documented especially at the cave bear den, hyena den and overlapping Neandertalian to Modern human camp site Balve Cave (Sauerland Karst, cf. archaeology in Günther 1964) where still a mammoth fauna is documented for that time (Diedrich 2010a). The last and by archaeological layers dated hyena remains were also found in the Balve Cave and are from the Late Middle Palaeolithic cave site reaching a maximum Aurignacian age documenting an overlapping of hyena den and human camp site use (Diedrich 2010a, b). In northern Germany