Northeast Siberia Research Articles

Soils of Steppe areas in the Cis-Tundra Open Woodland Subzone on the Right Bank of the Kolyma River in Its Lower Reaches

The small steppe plots (steppoids) occur at southern slopes among open larch forests of the Lower Kolyma area (northeast Siberia). Depending on a soil parent material they are divided into petrophytic (on a bedrock eluvo-diluvium) and thermophytic (on a silty loam of the Yedoma formation (Ice Complex)) steppoids. A xeromorphic deep thawing soils with diverse humus accumulative horizons, high roots content and considerable water stable powder-like structure develop under steppoids. Soils of steppoids are zooturbated, especially thermophytic ones. They differ from those of the surrounding taiga landscape in the following features: decreased actual and potential acidity; higher content of exchange bases, water-soluble salts, carbonates and organic nitrogen; smaller ratio between concentrations of oxalate- and dithionite-extractable iron. Dark mulle-like forms of humus on the surface of mineral grains are widely represented among the microaccumulations of organic matter in taiga-steppe soils. The cryoxerozem soil formation trait shows better in the event of petrophytic steppoids. Despite the similarity of the soils of thermophytic steppoids with steppe cryoarid ones, they differ in the absence of carbonate accumulative and criohumic horizons as well as the relatively high acidity. Flow-carbonaceous grey-humus lithozem and flow-carbonaceous grey-humus or duff dark-humus soils are distinguished within the petrophytic steppoids just as surface-turbated (zooturbated) grey-humus or duff dark-humus soils are distinguished within the thermophytic steppoids.

Habitation conditions of the cave lion in the middle Indigirka River basin, North-East Siberia, during the Middle and Late Pleniglacial: Reconstruction based on palynological data

Pollen analyses of the sediment from skulls cavities of two cave lions Panthera spelaea from the middle Indigirka River basin, North-East Siberia, were performed to reconstruct the habitat conditions of the animals and to estimate changes in vegetation and climatic conditions in the region. Composition of the pollen and non-pollen palynomorphs indicates that the predators most likely died on the river floodplain or near the shore of the thermokarst lake, where grass/sedge meadows and shrub thickets, providing rich grazing grounds for large herbivores, existed. Palynological data indicate that both in the early Middle Pleniglacial and in the LGM the regional vegetation included forest, shrub tundra, meadow, mire and steppe communities similar to modern cold steppes in central Yakutia. During early Marine Isotope Stage (MIS) 3, the participation of arboreal vegetation was greater than in the Last Glacial Maximum (LGM) due to higher summer temperatures. In MIS 2, the role of open herbaceous cryoxerotic communities was greater, which is associated with a higher continentality of climate and a decrease in winter temperatures. This reconstruction is consistent with the general sequence of landscape and climatic changes in the Arctic and Subarctic regions of Siberia in the Middle and Late Pleniglacial, based on paleobotanical studies of the locations of mammoth fauna and multidisciplinary studies of the Late Pleniglacial sediments from a broader area.

Precipitation-induced abrupt decrease of Siberian wildfire in summer 2022 under continued warming

Wildfires in Northeast (NE) Siberia have become more frequent owing to the warming climate, exerting a profound impact on the global carbon cycle. While an increase in global temperature is recognized as a primary driver of unprecedented wildfires, the role of precipitation during wildfire season is relatively unexplored. Here, we present evidence that an increase in summer precipitation led to a sudden decrease in NE Siberian wildfires, especially in 2022, notwithstanding the persistent warming trend in the northern high latitudes. The interannual variability of summer precipitation, linked to the large-scale atmospheric circulation, known as the Scandinavia (SCAND) pattern, significantly impacts the regulation of wildfires. Climate models project enhanced variability in summer precipitation, potentially amplifying year-to-year fluctuations in wildfire occurrences. The interplay between the temperature and precipitation patterns in NE Siberia under ongoing warming may increase the occurrence of extreme wildfires, leading to a substantial release of carbon and further contributing to climate warming.

Small-scale hydrological patterns in a Siberian permafrost ecosystem affected by drainage

Abstract. Climate warming and associated accelerated permafrost thaw in the Arctic lead to a shift in landscape patterns, hydrologic conditions, and release of carbon. In this context, the lateral transport of carbon and shifts therein following thaw remain poorly understood. Crucial hydrologic factors affecting the lateral distribution of carbon include the depth of the saturated zone above the permafrost table with respect to changes in water table and thaw depth and the connectivity of water-saturated zones. Landscape conditions are expected to change in the future due to rising temperatures and polygonal or flat floodplain Arctic tundra areas in various states of degradation; hydrologic conditions will also change. This study is focused on an experimental site near Chersky, northeast Siberia, where a drainage ditch was constructed in 2004 to simulate landscape degradation features that result in drier soil conditions and channeled water flow. We compared water levels and thaw depths in the drained area (dry soil conditions) with those in an adjacent control area (wet soil conditions). We also identified the sources of water at the site via stable water isotope analysis. We found substantial spatiotemporal changes in the water conditions at the drained site: (i) lower water tables resulting in drier soil conditions, (ii) quicker water flow through drier areas, (iii) larger saturation zones in wetter areas, and (iv) a higher proportion of permafrost meltwater in the liquid phase towards the end of the growing season. These findings suggest decreased lateral connectivity throughout the drained area. Shifts in hydraulic connectivity in combination with a shift in vegetation abundance and water sources may impact carbon sources and sinks as well as transport pathways. Identifying lateral transport patterns in areas with degrading permafrost is therefore crucial.

GIS analysis of lake and basin orientation, Yana–Indigirka Lowland, northeast Siberia

The purpose of this study is to investigate the environmental factors that influence the orientation of lakes and basins in continuous permafrost of the Yana–Indigirka Lowland, NE Siberia. In this area, 24,782 lakes each with an area of >10,000 m2 were digitized from Google Earth satellite imagery, and four categories of lakes and drained lake basins were identified in two sub-study areas from Sentinel 2 imagery. Regionally, the lakes show a single modal orientation east–west to ESE–WNW, which is broadly parallel to the prevailing wind from 80 to 90° recorded at the nearest meteorological stations during June–October, when the lakes are likely to have been partially or completely ice-free and therefore exposed to wave-induced currents. Regression analysis suggests that lake orientation tends to be strongest in flatter terrain (<1°) that is not formed in silt- and ice-rich yedoma deposits. Locally, however, two sub-study areas show two modes of almost equal size, with lakes and basins aligned ESE–WNW or NNE–SSW, and thus approximately either parallel to or perpendicular to prevailing winds. Local deviation from the ESE–WNW lake alignment in the sub-study areas is attributed to a sandy substrate and topographic control. Sandy substrates appear to favour perpendicular orientations, whereas elongate depressions aligned broadly east–west, and supporting meandering rivers, favour parallel orientations. Overall, therefore, the impact of prevailing summer wind direction on lake and basin orientation is moderated by environmental factors of topography and substrate.

Unadapted Foreign Language Insertions in Spoken Language of Tundra Yukaghir

The foreign language insertions in the language of the tundra Yukagirs-polyglots of the Lower Kolyma in Yakutia are considered for the first time. The relevance of the study is primarily dictated by the lack of research on contact phenomena in the Yukagir language as a whole, the decreasing number of speakers, and the importance of documenting this ancient language of Northeast Siberia. The goal of the study is to identify the functioning features of insertions in the modern spoken language of the tundra Yukagirs. The material consists of recordings of oral speech by Yukagirs in the form of polylogue, dialogue, and monologue, fragments of transcripts of which are introduced into scientific circulation for the first time. The analysis shows that insertions in Yukagir speech are realized through Yakut and Russian insertions, originating from various parts of speech of the guest languages. The author concludes the relevance of the Yakut language as the second language after the ethnic one, due to the higher frequency of Yakut elements in Yakut speech compared to Russian ones. It has been established that insertions are marked by empty and filled pauses, vocal, lexical-semantic, and paralinguistic hesitations. It is noted that the creative function is realized through the manner of using insertions by individual Yukagir polyglots in their speech.

Characterization of the Spectrum of Mitochondrial DNA Nucleotide Substitutions in Human Populations in High Altitude Environments

Using phylogenetic analysis of the nucleotide sequences of whole mitochondrial genomes (mtDNA), the spectra of germinal nucleotide substitutions (on the L-chain of mtDNA) were reconstructed in highland populations of the Pamirs and Tibet in comparison with regional indigenous groups of West Asia, Northeast Siberia, and South Siberia. No differences were found in the distribution of nucleotide substitution frequencies in the mtDNA spectra depending on the population distribution by altitude. Pyrimidine transitions dominate in all mtDNA spectra, and T → C substitutions are the most frequent among them. Next in frequency in most regional groups are A → G substitutions, but in the Pamir and northeast Asian groups G → A substitutions are prevalent. Of the transversions in all populations studied C → A replacements were found to be predominant, except for the Tibetan one, where A → C substitutions are more frequent. The lack of differences in the distribution of mtDNA mutations in high-altitude and non-highland populations indicates that the structure of mtDNA spectra in human populations is independent of the oxidative stress intensity in mitochondria.

Local Features of Ballads in Northeast Siberia: Plots of ‘The Mother-in-Law Held Captive by Her Son-in-Law’ and ‘Prince Volkonsky and the Gatekeeper’

This article aims to clarify the characteristics of the ballad genre among other works in Northeast Siberia (in Yakutia and a separate settlement in the Magadan region). It examines the local features of ballad song variants recorded from long-time residents of Northeast Yakutia. The source materials used are texts published in the collections “Folklore of Russian Ustye” (1986) and “Russian Epic Poetry of Siberia and the Far East” (1991). The article presents ballad songs of Russian settlers from the lower reaches of the Indigirka River and the Kolyma River basin. Recordings by D. I. Melikov and V. G. Bogoraz are also utilized. The study is conducted using descriptive and comparative methods, as well as some techniques of lexical-semantic analysis. The work continues the research related to specifying the repertoire, genre, and stylistic features that constitute the uniqueness of epic poetry in Northeast Yakutia recorded in the 19th-20th centuries. The specifics of their dissemination are characterized. The first recordings made in the 19th century are compared with ballad texts documented in the 20th century. Special attention is given to the ballad song “The Mother-in-Law Held Captive by Her Son-in-Law.” It is noted that this folklore specimen reflects certain historical realities related to the area where the song was circulated. It is reported that ballad texts were lost by the 1970s.

Bidimensional climatology and trends of Northern Hemisphere blocking utilizing a new detection method

AbstractIn this article, the meridional gradient of daily potential vorticity (PV) on the 330 K isentropic surface is used to identify atmospheric blocking events for the period 1979–2019. The associated two‐dimensional index considers not only Rossby wave breaking, but also energy dispersion and nonlinearity of blocking systems, and thus has a solid theoretical foundation. It also has the advantage of automatically excluding subtropical high‐pressure systems in summer and autumn. The index reveals that the Northern Hemisphere exhibits high blocking frequency over Euro‐Atlantic, North Pacific and Greenland in winter, spring and autumn, and over two wide‐extended bands at high latitudes in summer. Two prominent blocking episode (BE) intensity centres are found over the eastern Atlantic and eastern Pacific in all seasons, while the long‐lived BE is primarily situated in regions with high BE frequency. There is more frequent and longer‐lived BE in the Euro‐Atlantic sector than in the North Pacific, whereas the BE in the North Pacific is more intense. Notably, with the same poleward criterion for the four seasons, the BE frequency and duration are supposed to be overestimated in summer. Comparing our blocking detection method with previous blocking indices provides additional information about the long‐term trends for blocking frequency and intensity, which can be useful to our understanding of future extremes on climate time‐scales. It is found that both blocking frequency and intensity exhibit upward linear trends in the Ural region and Barents–Kara Sea in winter, Europe, northern North Pacific and East Siberia in spring, western Greenland in summer, as well as Norwegian Sea, Europe and North Atlantic in autumn, which point to increases in high‐impact weather events in these regions.

Absence of Large‐Scale Ice Masses in Central Northeast Siberia During the Late Pleistocene

AbstractOngoing speculation regarding the existence of large Late Pleistocene ice masses in Northeast Eurasia reflects the dearth of age constraints on glaciations across this vast region. Here, we report the first dates from the central part of Northeast Siberia, consisting of 22 cosmogenic 10Be exposure ages from boulders deriving from a sequence of three moraines in the Chersky Range. The dated moraine sequence indicates progressive contraction of maximum glacier extent from Marine Isotope Stage 6 to the Last Glacial Maximum, while the remotely‐sensed mapping indicates an older, more expansive glaciation in the region yet undated. Our results show that Late Pleistocene glaciations were limited to the highlands, and Northeast Siberia did not host a large, coalescent ice sheet during the Last Glacial Maximum or Marine Isotope Stage 6.

Subfossil Insect Collections From the Arctic of Northeast Asia and Northwest North America

Subfossil insects (mostly beetles) are common in the Late Cenozoic terrestrial loose deposits of the Arctic. The best-studied areas are those regions that remained ice-free during the Pleistocene — in Alaska and Yukon, northeast Siberia, and west Chukotka. Tertiary subfossil insects have been found in Alaska, Yukon, Canadian Northwest Territories, and Greenland. The northernmost sites (above 75°N) are Ellesmere and Meighen Islands in Canada, Kap Kobenhavn in Greenland, and Faddeyevsky and Navaya Sibir’ Islands in Siberia. Collections from North America and Russia are housed in research institutions such as The Geological Survey of Canada (GSC) in Ottawa, University of Alberta (UofA) in Edmonton, Paleontological Institute (PIN) in Moscow, and Institute of Plant and Animal Ecology in Yekaterinburg; collections from Greenland are housed in the Zoological Museum, University of Copenhagen. The collections are mainly used for research purposes, including reconstruction of past climate and environment, stratigraphy, origin of local faunas, and ecosystems of the past. A few extinct species have been described from the late Neogene and early Quaternary.

Transient Freeze‐Thaw Deformation Responses to the 2018 and 2019 Fires Near Batagaika Megaslump, Northeast Siberia

AbstractWildfires in Arctic regions impact landforms via permafrost degradation and subsequent deformation that can last for many years. However, it remains uncertain on if and how much deformations occur, and what controls their magnitude, particularly during the first couple of years. Here, we examine the transient post‐fire deformation responses near the Batagaika megaslump, which is the world's largest retrogressive thaw slump at Batagay, Sakha Republic. There were wildfires in the summers of 2018 and 2019 on the same slope, which could trigger the formation of another megaslump; many fires occurred nearby in 2019. We use interferometric synthetic aperture radar (InSAR) to measure surface displacements, including both post‐fire and span‐fire images. We also perform onsite measurements of temperature and thaw depth around the two scars near Batagaika megaslump in 2019, 2020, and 2021 and around the 2014 scar in 2019. At the three fire scars formed in 2018 and 2019, we demonstrate year‐to‐year and location‐specific changes in the amplitude of subsidence, heave, and duration. The 2018 scar shows cumulative subsidences of up to 10 cm by March 2021, more clearly than the nearby 2019 scar. On the other hand, another 2019 scar adjacent to the 2014 scar shows up to 13 cm net subsidence during the first span‐fire year, although the subsiding area is limited. These diverse transient post‐fire responses demonstrate that under the yedoma area the spatial heterogeneities of the active layer depth and the timing of fires will control subsequent thermokarst processes.

Bidirectional dispersals during the peopling of the North American Arctic

It is thought that Paleo-Inuit were the first people that settled the American Arctic about 5000 BP (before the present) from a migration that crossed Beringia from Northeast Asia. It is theorized that this group initially migrated to the North Slopes of Alaska and subsequently expanded eastward, eventually reaching Greenland. A second circumpolar dispersal of Neo-Inuit from the North Slopes associated with the Thule-Inuk culture has been postulated to have extended eastward around 800 BP, totally replacing the original Paleo-Inuit without admixing. Although generally accepted, this migration scenario is incompatible with previously reported indications of east to west gene flow across the American Arctic. Here we report on the Y-chromosome haplogroup and Y-STR diversity of the four circumpolar populations of the Tuva Republic (N = 24), Northeast Siberia (N = 9), Bethel, Alaska (N = 40), and Barrow, Alaska (N = 31). Four haplogroup lineages (Q-NWT01, Q-M3, Q-M346, and Q-M120) were detected, Q-NWT01 and Q-M3 being the most abundant at 11.11 and 66.67% in Northeast Siberia, 32.50 and 65.00% in Bethel, and 67.74 and 32.26% in Barrow, respectively. The same samples genotyped for Y-chromosome SNPs were typed for 17 Y-STYR loci using the AmpFlSTR Yfiler system. Age estimates and diversity values for the Q-NWT01 and Q-M3 mutations suggest extensive movement of male individuals along the entire longitudinal stretch of the American circumpolar region. Throughout the entire region, Q-M3 exhibits a west to east decreasing gradient in age and diversity while Q-NWT01 indicates the opposite with older TMRCA and higher diversity values running from east to west with the most recent estimates in Canada and Alaska. The high age and diversity values in Greenland are congruent with an origin of the Q-NWT01 mutation in the east of the circumpolar range about 2000–3000 ya. This scenario is incompatible with a complete biological replacement starting about 700 BP of Paleo-Inuit like the Dorset by the Thule-Inuit (Neo-Inuit), as is currently thought, and more parsimonious with gene flow carrying the NWT01 mutation from a pre-Thule population to the ancestors of the present-day Inuit.

Geochemical Characteristics of Soils to the Impact of Diamond Mining in Siberia (Russia)

This article presents the results of long-term research and monitoring of the soil cover exposed to the impact of the mining and processing plant developing diamond deposits in the northeast of Siberia. The soil collection includes 436 samples of different types of Cryosols. Soil pH; soil organic carbon (SOC); granulometric composition; and mobile forms of Pb, Ni, Mn, Cd, Co, Cr, Zn, Cu, and As were identified in the samples. Multivariate statistics of the correlation matrix, clustering analysis (CA), and principal component analysis (PCA) were used to determine the sources of heavy metals. The intensity of the accumulation of chemical elements in the soil was assessed using calculated concentration coefficients (Kc) and the index of total contamination of the soil cover (Zc). In the study area, Cryosols are characterized by biogenic accumulation of Ni, Mn, and Cd in the upper soil layer and Cr, Ni, Co, Mn, and Cu in the suprapermafrost horizon. Correlation matrix, CA, and PCA revealed three distinct sources that could be considered for the investigated potentially toxic elements (PTEs): anthropogenic, lithogenic, and the source which comes from a mixed contribution of anthropogenic and lithogenic factors. The most anthropogenic contribution in the heavy metals in the study area appears in Zn, Cd, As, and Pb. The assessment interpreted that origin of Mn in the area is most likely to be a natural source. The content of Co, Cr, and Ni are controlled by both lithogenic control and anthropogenic sources. Active accumulation of mobile forms of Mn, Zn, and Ni with anomalously high concentration coefficients can be traced in the soils in the impact zone of mining operations. Anthropogenic soil contamination is spread over an area of 260 km2.

Allometric equations and wood density parameters for estimating aboveground and woody debris biomass in Cajander larch (Larix cajanderi) forests of northeast Siberia

Abstract. Boreal forests are particularly vulnerable to climate warming, which increases the occurrence of natural disturbances, such as fires and insect outbreaks. It is therefore essential to better understand climate-induced changes in boreal vegetation dynamics. This requires accurate estimates of variations in biomass across regions and time. This remains challenging in the extensive larch forests of northeast Siberia because of the paucity of allometric equations and physical properties of woody debris needed for quantifying aboveground biomass pools from field surveys. Our study is the first to present values of mean squared diameter (MSD) and specific gravity that can be used to calculate fine dead and downed woody debris loads in Cajander larch (Larix cajanderi) forests using the line-intersect sampling approach. These values were derived from field measurements collected in 25 forest stands in the Republic of Sakha, Russia, and compared with values reported for other prevalent boreal tree species. We developed allometric equations relating diameter at breast height (DBH, at 1.3 m) to stem wood, stem bark, branches, foliage, and aboveground biomass based on measurements of 63 trees retrieved from previous studies. Differences between our allometric models and existing equations were assessed in predicting larch aboveground biomass in 53 forest stands sampled in the Republic of Sakha. We found that using fine woody debris (FWD) parameters from other boreal tree species and allometric equations developed in other regions may result in significantly lower biomass estimates in larch-dominated forests of northeast Siberia. The FWD parameters and allometric equations presented in our paper can be used to refine estimates of aboveground biomass in Cajander larch forests in northeast Siberia.

Distribution and Structure Analysis of Mountain Permafrost Landscape in Orulgan Ridge (Northeast Siberia) Using Google Earth Engine

An analysis of the landscape spatial structure and diversity in the mountain ranges of Northeast Siberia is essential to assess how tundra and boreal landscapes may respond to climate change and anthropogenic impacts in the vast mountainous permafrost of the Arctic regions. In addition, a precise landscape map is required for knowledge-based territorial planning and management. In this article, we aimed to explore and enhanced methods to analyse and map the permafrost landscape in Orulgan Ridge. The Google Earth Engine cloud platform was used to generate vegetation cover maps based on multi-fusion classification of Sentinel 2 MSI and Landsat 8 OLI time series data. Phenological features based on the monthly median values of time series Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), and Normalized Difference Moisture Index (NDMI) were used to recognize geobotanical units according to the hierarchical concept of permafrost landscapes by the Support Vector Machine (SVM) classifier. In addition, geomorphological variables of megarelief (mountains and river valleys) were identified using the GIS-based terrain analysis and landform classification of the ASTER GDEM scenes mosaic. The resulting environmental variables made it possible to categorize nine classes of mountain permafrost landscapes. The result obtained was compared with previous permafrost landscape maps, which revealed a significant difference in distribution and spatial structure of intrazonal valleys and mountain tundra landscapes. Analysis of the landscape structure revealed a significant distribution of classes of mountain Larix-sparse forests and tundra. Landscape diversity was described by six longitudinal and latitudinal landscape hypsometric profiles. River valleys allow boreal–taiga landscapes to move up to high-mountainous regions. The features of the landscape structure and diversity of the ridge are noted, which, along with the specific spatial organization of vegetation and relief, can be of key importance for environmental monitoring and the study of regional variability of climatic changes.

Eskimo Problem in the Light of New Data

Purpose. The problem of the origin of the Eskimos has received considerable attention, at the same time also providing insights about human presence in far Northeast Siberia and America. I review earlier studies and discuss some of the more exciting recent results emerging from ancient DNA data sets. I also highlight important features of genetic and archeological data and discuss key questions and future research directions. Results. The Paleo-Eskimos and Neo-Eskimos ancestors along the Q-NWT01 Y-DNA line lived in the Kolyma River basin at the turn of the Late Pleistocene and Early Holocene. The migration of the East Asian ancestors of the Paleo-Eskimos was associated with the representatives of the Neolithic cultures of Northeast Asia, which brought the ancestral haplotype for mtDNA haplogroup D2a to Alaska. The emergence of the Neo-Eskimo cultures took place in the Bering strait area on the basis of the local Paleo-Eskimo tradition and under the influence of the cultural traditions of Southwestern Alaska and Chukotka. The Ust'-Belaya culture of Chukotka could act as a genetic source for the development of the Neo-Eskimo cultures.Conclusion. Analysis of ancient DNA from human remains over the past decade has had a transformative effect on the study of the origin of the Eskimos. Data sets of ancient DNA have revealed an increasingly complex picture of human demographic history in North-East of Asia and America and development of Paleo-Eskimo and Neo-Eskimo traditions, suggesting multiple waves of migration over the Bering Strait and episodes of admixture of different groups of population, including Ancient Paleosiberian, East Asian, Paleo-Indian, Paleo-Eskimos, Neo-Eskimos and others.

Grazing enhances carbon cycling but reduces methane emission during peak growing season in the Siberian Pleistocene Park tundra site

Abstract. Large-herbivore grazing has been shown to substantially alter tundra soil and vegetation properties as well as carbon fluxes, yet observational evidence to quantify the impact of herbivore introduction into Arctic permafrost ecosystems remains sparse. In this study we investigated growing-season CO2 and CH4 fluxes with flux chambers on a former wet tussock tundra inside Pleistocene Park, a landscape experiment in northeast Siberia with a 22-year history of grazing. Reference data for an undisturbed system were collected on a nearby ungrazed tussock tundra. Linked to a reduction in soil moisture, topsoil temperatures at the grazed site reacted 1 order of magnitude faster to changes in air temperatures compared to the ungrazed site and were significantly higher, and the difference strongly decreased with depth. Overall, both GPP (gross primary productivity, i.e., CO2 uptake by photosynthesis) and Reco (ecosystem respiration, i.e., CO2 release from the ecosystem) were significantly higher at the grazed site with notable variations across plots at each site. The increases in CO2 component fluxes largely compensated for each other, leaving NEE (net ecosystem exchange) similar across grazed and ungrazed sites for the observation period. Soil moisture and CH4 fluxes at the grazed site decreased over the observation period, while in contrast the constantly waterlogged soils at the ungrazed site kept CH4 fluxes at significantly higher levels. Our results indicate that grazing of large herbivores may promote topsoil warming and drying, in this way effectively accelerating CO2 turnover while decreasing methane emissions in the summer months of peak ecosystem activity. Since we lack quantitative information on the pre-treatment status of the grazed ecosystem, however, these findings need to be considered qualitative trends for the peak growing season, and absolute differences between treatments are subject to elevated uncertainty. Moreover, our experiment did not include autumn and winter fluxes, and thus no inferences can be made for the annual NEE and CH4 budgets in tundra ecosystems.

Where Is the Nomadic Family? Rigid Laws and Flexible Tundra Life in North-East Siberia

Abstract We start from a puzzle: in remote Arctic regions of the Sakha Republic (Yakutia), why are many reindeer-herding families excluded from official 'nomadic family' benefits? The Republic's Nomadic Family Law is supposed to support indigenous minorities leading a 'traditional' lifestyle, but it often fails. We identify three models of family structure at work, each matching the fluidity of the physical environment and productive process more or less realistically. While our fieldwork reveals a highly flexible and all-embracing indigenous understanding of relatedness, analysis of the urban officials' laws show them to be based on unexamined concepts of 'family' rooted in Russian terminology and based on narrow ideas of the nuclear family rather than on the complementary distribution of labour across a shared space. We suggest that legal initiatives should include a wider ethnographic basis to provide a better understanding of emic concepts, while also consulting the local people most directly affected.

The middle–late Tournaisian crisis in conodont diversity: a comparison between Northeast Laurussia and Northeast Siberia

The middle–late Tournaisian (Hastarian–Ivorian) transition is marked by isotopic and sedimentological evidence of climatic cooling and glaciations accompanied by a sea level fall and changes in global ocean circulation. At this time, the extinction among conodonts was followed by its gradual recovery in the late Tournaisian–early Viséan. Siphonodellids, representing an important part of conodont assemblages in the early–middle Tournaisian, became extinct. This study aims to compare conodont diversity dynamics in Northeast Laurussia and Northeast Siberia. The materials used range in paleolatitudinal gradients from 20°N (the north of the Urals and Pechora Craton) up to 45°N (Northeast Siberia), and in paleoclimatic gradient from an equatorial to a warm subtropical climate. The middle and late Tournaisian conodont associations of these regions demonstrate a high similarity in taxonomic composition and diversity dynamics, which may suggest that the glaciation and the following decrease in temperature probably was not the direct cause of conodont extinction; instead, the changes in the food web implied by the carbon isotope compositions of conodont elements and host carbonates could have been the main driver of the crisis in conodont diversity