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Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost, and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation, and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.5 to 1 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. [ABSTRACT FROM AUTHOR]

The organic carbon (OC) pool accumulated in Arctic permafrost (perennially frozen ground) equals the carbon stored in the recent atmosphere. To give an idea of how Yedoma region permafrost could respond under future climatic warming, we conducted a study to quantify the organic matter quality for future decomposition of late Pleistocene (Yedoma) and Holocene (thermokarst) deposits on the Buor Khaya Peninsula, northeast Siberia. The objective of this study was to develop a stratigraphic classified organic matter quality characterization. For this purpose the degree of organic matter decomposition was estimated by using a multiproxy approach. We applied sedimentological (grain-size analyses, bulk density, ice content) and geochemical parameters (total OC, stable carbon isotopes (δ13C), carbon : nitrogen (C/N) ratios) as well as lipid biomarkers (n-alkanes, n-fatty acids, hopanes, triterpenoids, and biomarker proxies/indices: average chain length, carbon preference index (CPI), and higher plant fatty acid index (HPFA)). Our results show that the Yedoma and thermokarst organic matter qualities exhibit no obvious degradation -- depth trend. The C/N, δ13C, and hop-17(21)-ene values and the HPFA index show a better quality of the organic matter stored in thermokarst deposits compared to Yedoma deposits, but the CPI points in the other direction. As the ranges of the proxies mostly overlap, we interpret this as to indicate similar quality for both kind of deposits with perhaps slightly better thermokarst organic matter quality. Supported by principal component analyses, the sediment parameters and quality proxies of Yedoma and thermokarst deposits could not be clearly separated from each other. This lack of clear quality differences revealed that the organic matter vulnerability is heterogeneous, independent from radiocarbon age and depends on different decomposition trajectories and the previous decomposition and preservation history. Elucidating this was one of the major novelties of our multiproxy study. With the addition of biomarker data, it was possible to show that permafrost organic matter degradation likely occurs via a combination of (uncompleted) degradation cycles or a cascade of degradation steps rather than as a linear function of age or sediment facies. We conclude that the amount of organic matter in the studied sediments is high for mineral soils and of good quality and therefore susceptible to future decomposition. The missing depth trends reveal that permafrost acts like a giant freezer, preserving the constant quality of ancient organic matter independently from its age. When unde-composed Yedoma organic matter is mobilized via thermokarst processes, the fate of this carbon depends largely on the environmental conditions; the carbon could be preserved in an undecomposed state till refreezing occurs. If recent input has occurred, thermokarst organic matter could be of a better quality than that found in Yedoma deposits. [ABSTRACT FROM AUTHOR]

Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N-69.5° N) representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe), arsenic (As), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co) and mercury (Hg) in di?erent soil types developed in di?erent geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex) in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island) showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA) revealed that soil oxides play a signi?cant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were similar to background levels reported for other pristine arctic areas and did not exceed mean global background concentrations examined for the continental crust as well as for the world's soils. [ABSTRACT FROM AUTHOR]

This paper evaluates the relative contribution of light and temperature on net ecosystem CO2 uptake during the 2006 growing season in a polygonal tundra ecosystem in the Lena River Delta in Northern Siberia (72º220 N, 126º300 E). We demonstrate that the timing of warm periods may be an important determinant of the magnitude of the ecosystem's carbon sink function, as they drive temperature-induced changes in respiration. Hot spells during the early portion of the growing season are shown to be more influential in creating mid-day surface-to-atmosphere net ecosystem CO2 exchange fluxes than those occurring later in the season. In this work we also develop and present a bulk flux partition model to better account for tundra plant physiology and the specific light conditions of the arctic region that preclude the successful use of traditional partition methods that derive a respiration-temperature relationship from all night-time data. Night-time, growing season measurements are rare during the arctic summer, however, so the new method allows for temporal variation in the parameters describing both ecosystem respiration and gross uptake by fitting both processes at the same time. Much of the apparent temperature sensitivity of respiration seen in the traditional partition method is revealed in the new method to reflect seasonal changes in basal respiration rates. Understanding and quantifying the flux partition is an essential precursor to describing links between assimilation and respiration at different time scales, as it allows a more confident evaluation of measured net exchange over a broader range of environmental conditions. The growing season CO2 sink estimated by this study is similar to those reported previously for this site, and is substantial enough to withstand the long, low-level respiratory CO2 release during the rest of the year to maintain the site's CO2 sink function on an annual basis. [ABSTRACT FROM AUTHOR]

Climate change is particularly strong in Northern Eurasia and substantial ecological changes are expected in this wide region. The reshaping and the migration northward of bioclimatic zones may offer opportunities for agriculture development in western and central Siberia. However, the bioclimatic vegetation models currently employed for projections still do not consider soil fertility whereas it is highly critical for plant growth. In the present study, we surveyed the phosphorus (P) status in the south-west of Siberia where soils are developed on loess parent material. We selected six sites differing by pedoclimate conditions and sampled the soil at different depths down to one meter in aspen (Populus tremula L.) forest as well as in grassland areas. The P status was assessed by conventional methods and by isotope dilution kinetics. We found that P concentrations and stocks, as well as their distribution through the soil profile, were rather homogeneous at the studied regional scale, although there were some differences among sites (particularly in organic P). The young age of the soils, together with slow kinetics of soil forming processes, have probably not yet conducted to a sufficiently wide range of soil physico-chemical conditions to observe more diverging P status. The comparison of our dataset to similar vegetation contexts on the global scale revealed that the soils of south-western Siberia, and more generally of Northern Eurasia, has often (very) high levels of total, organic and inorganic P. The amount of plant-available P in topsoils, estimated by the isotopically exchangeable phosphate ions, was not particularly high, but intermediate at the global scale. However, large stocks of plant-available P are stored in subsurface layers which have currently low fine root exploration intensities. These results suggest that the P resource is unlikely to constrain vegetation growth and agriculture development in the present and near future conditions. [ABSTRACT FROM AUTHOR]

This study introduces a methodology for land cover mapping across extensive areas, utilizing multitemporal Sentinel-1 Synthetic Aperture Radar (SAR) data. The objective is to effectively process SAR data to extract spatio-temporal features that encapsulate temporal patterns within various land cover classes. The paper outlines the approach for processing multitemporal SAR data and presents an innovative technique for the selection of training points from an existing Medium Resolution Land Cover (MRLC) map. The methodology was tested across four distinct regions of interest, each spanning 100 × 100 km2, located in Siberia, Italy, Brazil, and Africa. These regions were chosen to evaluate the methodology's applicability in diverse climate environments. The study reports both qualitative and quantitative results, showcasing the validity of the proposed procedure and the potential of SAR data for land cover mapping. The experimental outcomes demonstrate an average increase of 16% in overall accuracy compared to existing global products. The results suggest that the presented approach holds promise for enhancing land cover mapping accuracy, particularly when applied to extensive areas with varying land cover classes and environmental conditions. The ability to leverage multitemporal SAR data for this purpose opens new possibilities for improving global land cover maps and their applications. [ABSTRACT FROM AUTHOR]

Rapid Arctic warming is expected to result in widespread permafrost degradation. However, observations show that site-specific conditions (vegetation and soils) may offset the reaction of permafrost to climate change. This paper summarizes 43 years of interannual seasonal thaw observations from tundra landscapes surrounding the Marre-Sale on the west coast of the Yamal Peninsula, northwest Siberia. This robust dataset includes landscape-specific climate, active layer thickness, soil moisture, and vegetation observations at multiple scales. Long-term trends from these hierarchically scaled observations indicate that drained landscapes exhibit the most pronounced responses to changing climatic conditions, while moist and wet tundra landscapes exhibit decreasing active layer thickness, and river floodplain landscapes do not show changes in the active layer. The slow increase in seasonal thaw depth despite significant warming observed over the last four decades on the Yamal Peninsula can be explained by thickening moss covers and ground surface subsidence as the transient layer (ice-rich upper permafrost soil horizon) thaws and compacts. The uneven proliferation of specific vegetation communities, primarily mosses, is significantly contributing to spatial variability observed in active layer dynamics. Based on these findings, we recommend that regional permafrost assessments employ a mean landscape-scale active layer thickness that weights the proportions of different landscape types. [ABSTRACT FROM AUTHOR]

Deciduous shrubs are expected to rapidly expand in the Arctic during the coming decades due to climate warming. A transition towards more shrub-dominated tundra may have large implications for the regional surface energy balance, permafrost stability and carbon storage capacity, with consequences for the global climate system. However, little information is available on the natural long-term shrub growth response to climatic variability. Our aim was to determine the climate factor and time period that are most important to annual shrub growth in our research site in NE-Siberia. Therefore, we determined annual radial growth rates in Salix pulchra and Betula nana shrubs by measuring ring widths. We constructed shrub ring width chronologies and compared growth rates to regional climate and remotely sensed greenness data. Early summer temperature was the most important factor influencing ring width of S. pulchra (Pearson's r = 0.73, p < 0.001) and B. nana (Pearson's r = 0.46, p < 0.001). No effect of winter precipitation on shrub growth was observed. In contrast, summer precipitation of the previous year correlated positively with B. nana ring width (r = 0.42, p < 0.01), suggesting that wet summers facilitate shrub growth in the following growing season. S. pulchra ring width correlated positively with peak summer NDVI, despite the small coverage of S. pulchra shrubs (< 5% surface cover) in our research area. We provide the first climate-growth study on shrubs for Northeast Siberia, the largest tundra region in the world. We show that two deciduous shrub species with markedly different growth forms have a similar growth response to changes in climate. The obtained shrub growth response to climate variability in the past increases our understanding of the mechanisms underlying current shrub expansion, which is required to predict future climate-driven tundra vegetation shifts. [ABSTRACT FROM AUTHOR]

Climate change increases the frequency of forest fires throughout the entire boreal zone. This paper examines the long-term wildfire dynamics in pine forests of Central Siberia, relationships between environmental and climatic variables on the one hand and the occurrence frequency of fires and size of burnt forest areas on the other, and the postfire dynamics of vegetation cover productivity. A coupled analysis of ground survey data, remote sensing data (spectroradiometric and gravimetric information collected by the Terra/MODIS and GRACE satellites), and dendroecological data is performed. In the period from the 18th to the 20th century, fire return intervals decreased from 33 to 20–25 years. No statistically significant trends in fire occurrence frequency were identified in the current century; however, catastrophic (i.e., affecting more than 1 million ha) fires were observed in its second decade, and both the number of fires and size of burnt areas have significantly increased (by 3.5 and 3.0 times, respectively). The frequency of fires and size of burnt areas closely correlate with wetting and temperature conditions in the prefire period. Furthermore, fire statistics parameters correlate with wetting conditions (precipitation amount, moisture content in the ground cover and soil, and the Self-Calibrated Palmer Drought Severity Index (sc-PDSI)) stronger than with air temperature. It is shown that equivalent water thickness values obtained using gravimetric methods can be used in fire risk assessments. High correlation levels were identified between the growth index of pine trees and vegetation cover productivity indices (i.e., gross primary productivity (GPP) and net primary productivity (NPP)) generated based on remote sensing data. The results indicate that these indices can be used to estimate forest stand productivity dynamics. The vegetation cover productivity and the radial growth index of pine trees in burnt areas quickly (within a decade) restore to prefire values, which indicates that northern pine forests retain their carbon sequestration function despite climate change and the increasing frequency of fires. [ABSTRACT FROM AUTHOR]

This paper presents the results of 30 years of permafrost thermal monitoring in the Tiksi area in the eastern Russian Arctic. At a stone ridge site, the mean annual temperatures in the upper 30 m of the ground have increased by 1–2.4 °C compared to the first years of observations, with trends of °C/yr. At the same time, its change was uneven. In the last 20 years, the rate of increase has increased compared with the first decade of observations. At wet tundra sites in the foothill plain, the mean annual temperatures at the top of permafrost have increased by 2.4–2.6 °C between 2005 and 2022 at rates of 0.11–0.15 °C/yr, and the active layer thicknesses have increased at rates of 0.05–0.41 cm/yr. [ABSTRACT FROM AUTHOR]

The energy sector is one of the most important pollutants in the atmosphere and causes significant emissions of greenhouse gases. In Russia, coal is the main contributor to the fossil fuel consumption of thermal power plants and boilers, thus affecting atmospheric air pollution by releasing particulate matter and nitrogen oxides, which are strongly associated with a negative impact on human health. This problem is especially acute for the resource regions of Yenisei, Siberia, a 2.5+ mln sq km macro-region in the very heart of Russia. In this paper, we analyze the impact of the structure of electricity and heat generation on emissions of pollutants and climate-active gases in Yenisei, Siberia, and give an overview of their social, ecological, and economic effects. More than 75% of electricity in Yenisei, Siberia, is produced by hydroelectric power plants that do not pollute the atmosphere. The rest of the electricity is generated in the cogeneration mode by thermal power plants, which are cores of the heat supply designs of cities. The share of individual coal-powered heat sources is still high. A detailed analysis of existing equipment and technologies at existing thermal power plants is needed to select options for their modernization to reduce emissions while keeping coal in use. Our calculations for the biggest cities of Krasnoyarsk Krai show that investments in the transition to heating with pellets will require RUB 184.7 million for Nazarovo and RUB 313.9 million for Kansk. At the same time, switching to electric heating is more than twice as expensive: RUB 498.6 million for Nazarovo and RUB 847.5 million for Kansk. The additional costs will range from RUB 21 to RUB 45.4 thousand per household per year for the pellet variant and from RUB 56.8 to RUB 122.5 thousand per year for electric heating, which could triple the annual heating costs. Thus, these options are unlikely to be implemented without direct state support. We argue that creating an attractive living environment in Yenisei, Siberia, must begin with intensive public investment in mitigating the environmental externalities caused by coal emissions. [ABSTRACT FROM AUTHOR]

This paper presents the results of studies aimed at identifying statistical relationships between the landscape structure and variability in Siberian stone pine (Pinus sibirica) increments in the permafrost–hillocky northern-taiga landscapes of Western Siberia (Nadym River basin). Dendrochronologies of Siberian stone pine growing on frost mounds of different types are compiled. Principal component analysis is applied to obtain independent variables that describe the site and landscape structure of the territory. Cores from 512 trees growing on 23 frost mounds are analyzed. The following methods are used: crossdating, dendrochronological standardization, and the elimination of monotonic trends for each tree. Results of the classification of Sentinel satellite images were used to calculate the proportions of lakes, forests, sparse forests, floating bogs, and flat–hillocky peat bogs, with the radius of the vicinity of a frost mound of 100‒2000 m. Correlation, dispersion, and regression analyses are used in the analysis of the dependence of the median increment on the characteristic of the mound site and landscape neighborhoods. It has been established that on high mounds the variability in increments is higher on tops than on slopes, whereas the situation is often reversed on low mounds. It is also found that the tops and slopes of the frost mounds respond differently to climatic fluctuations depending on the landscape structure and the height of the mound: the close proximity of lakes reduces the variability of phytoproductive functioning on the summit surfaces. It is revealed that the sensitivity of Siberian stone pine growth to temperature fluctuations increases with an increase in the diversity of the facies structure caused by the development of thermokarst subsidence and cryogenic cracks. [ABSTRACT FROM AUTHOR]

Changes in climate, land-use and pollution are having disproportionate impacts on ecosystems and biodiversity of arctic and mountain ecosystems. While these impacts are well-documented for many areas of the Arctic and alpine regions, some isolated and inaccessible mountain areas are poorly studied. Furthermore, even in well-studied regions, assessments of biodiversity and species responses to environmental change are biased towards vascular plants and cryptogams, particularly bryophytes are far less represented. This paper aims to document the environments of the remote and inaccessible Altai-Sayan mountain mires and particularly their bryofloras where threatened species exist and species new to the regional flora are still being found. As these mountain mires are relatively inaccessible, changes in drivers of change and their ecosystem and biodiversity impacts have not been monitored. However, the remoteness of the mires has so far protected them and their species. In this study, we describe the mires, their bryophyte species and the expected impacts of environmental stressors to bring attention to the urgency of documenting change and conserving these pristine ecosystems. [ABSTRACT FROM AUTHOR]

The paper presents the dynamics of the hydrothermal coefficients characterizing agroclimatic resources on the territory of Siberia within the coordinates of 50°–65° N, 60°–120° E during modern climate change. The intensity, frequency, and duration of adverse weather phenomena for agriculture (the atmospheric droughts and moisture excess conditions) are analyzed. The Ped' drought index () and the standardized precipitation evapotranspiration index (SPEI) calculated from the data of 134 weather stations and the ERA5 reanalysis are used as an indicator. In Eastern Siberia and in the west of the analyzed territory, there is an increase in aridity (a trend is 0.2–0.5 per decade). Northern regions of Kazakhstan, the Sayan Mountains, and the West Siberian Plain were characterized by a relative stability of hydrothermal conditions in 1950–2020 (statistically significant changes are not revealed). A direct linear dependence of hydrothermal conditions on large-scale circulation processes have been not detected for most cases. The greatest number of statistically significant correlation coefficients has been obtained for the drought index and the SCAND (Scandinavia teleconnection pattern) index. [ABSTRACT FROM AUTHOR]

The upper part of the subsurface component of the Earth's cryosphere—polygonal peatlands—are considered in this paper. The polygonal peatlands are widespread in the cryolithozone in northwestern Siberia. When the upper permafrost layer thaws under the influence of climatic fluctuations, the ice-bearing transition and intermediate layers in the polygonal peatlands serve as a buffer zone. Therefore, the identification of these layers is a crucial task. The specific features of the layers, their relationship with ice of various origins, and the properties of peat have been determined. The differences in the structure of the intermediate layer, associated with polygonal microrelief of the surface, have been revealed. Thawing of the transitional layer against the background of modern warming has been recorded on the basis of monitoring of a seasonally thawed layer. To identify the transitional and intermediate layers, the indicators—the cryogenic structure, degree of preservation, color, water content, and density of peat—have been determined. [ABSTRACT FROM AUTHOR]

The paper presents the results of an analysis of the spatial distribution of forest fires and their causes in the forest areas of Central Siberia in 1987–2020. An increase in the share of fires from lightning discharges has been recorded ( , ). A spatiotemporal extrapolation of long-term meteorological data series has been performed. An increase in thunderstorm activity by at least 30% relative to the average annual norm for the end of the 20th century has been revealed for the entire territory of Central Siberia. It is shown that if current trends are maintained until 2100, the number of lightning discharges during the fire season (March–September) will determine up to 10–40% increase in the number of fires caused by lightning. Thunderstorm activity can be one of the significant factors in the toughening of fire regimes in Central Siberia. [ABSTRACT FROM AUTHOR]

This paper presents the results of a trend and correlation analysis of the air temperature and the normalized difference vegetation index (NDVI) performed for the warm season in the taiga and tundra zones of West Siberia over the period of 1982–2015. Both in the taiga and tundra zones, a significant increase in NDVI values is observed in certain months of the spring–summer period amid significant (α = 0.05) positive air temperature trends. The air temperature and NDVI trends have been computed for the taiga and tundra zones from April to October over the period of 1982–2015; the irregularity of their spatial distribution in the study area is demonstrated. It is established that the vegetation development during the warm season is significantly determined by its development in the first month of the warm season (May for taiga and June for tundra). In the taiga zone, the NDVI value in May is formed under the influence of April and May temperatures; in the tundra zone, it is formed in June under the influence of June temperatures. However, the input of May temperatures into the formation of the tundra vegetation cover has increased in recent years due to climate warming. Significant correlation coefficients between the NDVI and averaged temperatures in April–May and May–June are typical for most of the study area, except for coastal northern regions in the first case and southwestern regions in the second case. [ABSTRACT FROM AUTHOR]

Arctic terrestrial ecosystems near the treeline in river lowlands are vulnerable to the changing climate and seasonal extreme events, including flooding. We set up a simple camera monitoring system to record the timings and durations of the leafy period and the spring flush of river water at three observation sites (Boydom [B]: 70.64°N, 148.15°E; Kodac [K]:70.56°N, 148.26°E; Verkhny‐Khatistakh [VK]:70.25°N,147.47°E) in the Indigirka lowland, in Northeastern Siberia. Time‐lapse digital cameras were located at seven points across the three sites. The time intervals were 1–4 or 24 hours. The minimum and maximum monitoring periods were 2 years (July 2016 to August 2018) at B and 5 years (August 2013 to July 2018) at K. One camera documented the timings of river ice melt and open water periods from the riverbank of the Kryvaya River, one of the small tributaries of the Indigirka River. The other six cameras recorded several types of ground cover typical of the area, including larch trees (Larix cajanderi), shrubs (including Salix spp. and Betula nana), forbs, mosses and graminoids in an ecosystem of sparsely forested shrublands, wetlands and riversides. The data consists of 45,617 JPEG‐format images. This dataset can be used to detect the onset and offset of the growing season and to capture the ice melt timing and water cover periods in wetlands and riversides. It may be useful in validating satellite data such as the vegetation remote sensing index for remote and little‐known areas. These data may contribute to the study of the role of high‐latitude ecosystems in global climate changes. The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-02.1/jalter-en. [Correction added on 7 September 2020, after first online publication: JaLTER URL has been updated.] [ABSTRACT FROM AUTHOR]

An understanding of how boreal forest composition responds to global environmental changes is an important challenge to predicting the future global carbon balance. Boreal forests are the most significant sink for atmospheric carbon dioxide; however, their sequestration capacity is highly sensitive to ongoing climate changes. The combination of the hydrothermal conditions of a territory strongly regulates its biogeochemical processes. The carbon fluxes in boreal forests are strongly mediated by the ground vegetation cover, composed of mosses (mesic) and lichens (xeric). Despite the concurrence of xeric and mesic vegetation types, their responses to climate variations varies significantly. Soil emission is an informative indicator of ecosystem functioning. In this study, we focused on the soil CO2 dynamics during frost-free seasons with different precipitation regimes in the xeric and mesic boreal ecosystems of Central Siberia. Seasonal measurements of soil CO2 emissions were conducted during frost-free seasons using the dynamic chamber method. Our findings reveal that the precipitation regimes of each year may control the seasonal soil emission dynamics. The soil moisture is the most important driver of emissions growth in the water-limited lichen pine forest (R2adj. = 18%). The soil temperature plays the largest role in the feather moss pine forest during the dry (R2adj. = 31%) seasons, and in the lichen pine forest during the wet (R2adj. = 41%) seasons. The cumulative efflux for the xeric and mesic sites is mostly related to the hydrothermal conditions, and not to the differences in ground vegetation cover. During the dry seasons, on average, the soil CO2 emissions are 45% lower than during the wet seasons for both sites. These findings emphasize the need for estimating and including the hydrothermal characteristics of the growing season for detailed emission assessments. [ABSTRACT FROM AUTHOR]

The Arctic air mass is the cold, dry body of air slowly moving eastwards around the North Pole in the northern hemisphere. Its southern boundary consists of four planetary waves known as the Rossby waves that mark the interface with subtropical air bringing heat polewards. The Arctic air mass is constantly being modified by the addition of heat and moisture over the oceans, as well as by winter cooling over the land masses due to limited incoming solar radiation and constant reradiation of heat into the atmosphere. The coldest air in winter is located over northeastern Siberia and moves east, cooling Canada. Warm ocean currents add large quantities of heat to the air mass moving over them, but without this addition of heat, the Arctic air mass becomes significantly colder. Research in Tibet and Northeast Asia on depression of sea level shows that during the Late Wisconsin cold event (65–10 ka B.P.), vast quantities of sea water were sequestered on land primarily as ice sheets, exposing the sea bed in the Bering Strait from 50–10 ka B.P. together with the bottom of the South China Sea between 30–20 ka B.P.. The East China Monsoon failed to reach Tibet and much of Northeast China, resulting in severe cooling of northeast Siberia and northern Tibet. This, in turn, caused severe cooling in eastern Canada together with the development of a vast, predominantly cold-based ice sheet. As the sea levels started to rise (about 19 ka B.P.), the East China Monsoon slowly redeveloped and a gradual warming took place on both continents. However, along the west side of the North American Cordillera, the Late Wisconsin glaciation only began in 29 ka B.P. but continued along the west coast until about 10 ka B.P. This paper explores the relationship of the Late Wisconsin history on the two continents, together with the mechanisms causing the landforms and climatic differences. Finally, the probable effects of these climatic changes on the early peopling of North America are discussed. [ABSTRACT FROM AUTHOR]

This paper recommends a potentially ambitious, reformative view of engagement with the Indigenous societies of the Eurasian North in the context of biodiversity loss and climate change. The Eurasian North enters this new era still in a social and economic context that sees few guarantees for the rights of Indigenous peoples. Yet the Eurasian North contains the last nomads of the Arctic – Nenets, Chukchi and Even peoples who have been able to maintain their cultures and civilisations under many economic and climate pressures. This paper argues that we need a revised understanding of biological and climate assessments in the Arctic – a comprehensive one that positions Indigenous communities as a part of their homelands. Using oral histories from the Sámi of Finland and Murmansk, Russia, as well as two nomadic communities in the Republic of Sakha-Yakutia, Siberia, Russia, this paper discusses the notion of ‘rebirth of Indigenous nations on the land’. By juxtaposing the theoretical framework of Even indigenous scholar Vasilii Robbek (2007) with these case studies a potentially new view emerges. This challenges the disappearance and loss of Indigenous cultures of the Arctic, and instead develops pathways that centre on hope and healing. It indicates the link between preservation of traditional human systems and climate and biodiversity assessment. People of the land are returning to their land with knowledge and histories intact. A key engine for this is the establishment of Indigenous nomadic schools across the region to preserve Indigenous knowledge. [ABSTRACT FROM AUTHOR]

Wildfires emit atmospheric aerosols, affecting climate and air quality. Siberia is a known source region of wildfires. However, comprehensive knowledge regarding the impact associated with particulate matter pollution due to Siberian wildfires on climate and air quality and their effects on mortality and the economy under present and near‐future warmer atmospheric conditions remains poor. Thus, we performed model sensitivity experiments (atmospheric model and coupled atmosphere‐ocean model settings) simulating the effects of changing Siberian wildfire emissions under the present and near‐future climate conditions, using the Model for Interdisciplinary Research on Climate version 5 (MIROC5). Increased Siberian wildfire smoke likely caused a cooling effect in broad areas of the Northern Hemisphere and worsened the air quality near the source and in the downwind region (i.e., East Asia). The more Siberian wildfires occur, the more air pollution is present in those regions, which likely increases mortality and welfare losses there. However, the total impact of changing temperature on the gross domestic product under present and near‐future climate conditions is ambiguous. Our comprehensive results on the air quality changes due to Siberian wildfires under present and near‐future climate conditions suggest that increased efforts to limit the aerosol impact of Siberian wildfires are crucial to prevent possible excess mortality and economic losses. Plain Language Summary: Comprehensive knowledge of worsening air quality due to increased Siberian wildfires and its impact on climate and economy is needed to assess the impact of such fires both near their source and in the surrounding regions. Therefore, we performed global climate model simulations and analyzed the changing atmospheric aerosol emissions, including a precursor gas, from Siberian wildfires under the present and near‐future climate conditions using the Japanese global climate model called MIROC5. The increased aerosol emissions from Siberian wildfires generated a cooling effect in broad areas of the Northern Hemisphere and worsened the air quality near the source and in the downwind areas of East Asia. The effects we observed are associated with excess mortality and economic welfare losses. Future studies are needed to fully understand and prevent those negative impacts. Key Points: Comprehensive impacts of increasing Siberian wildfires on air quality, climate, and economy were estimated using the MIROC5 climate modelWe observed a cooling effect broadly across the Northern Hemisphere and worsened air quality near wildfire source and downwind regionsThe effects are closely related to lowering achievement rates of PM2.5 environmental standards, excess mortality, and economic losses [ABSTRACT FROM AUTHOR]

The bottom sediments of lakes with different mineralization located in the basins of inland areas are high-resolution archives of climate and environmental changes. We present results of study of the Late Pleistocene-Holocene sediments of freshwater Lake Baunt, one of the lakes of the Baunt (Tsipa) depression in the permafrost zone in northern Buryatia. The sediments were studied by XRD, IR spectroscopy, laser granulometry, elemental analysis, AMS dating, etc. Mineral analysis of the bottom sediments with an age of ~18 ka has revealed predominant phyllosilicates, quartz, and feldspars. Mathematical modeling of complex XRD spectra made it possible to identify chlorite, muscovite, illite, mixed-layer illite-smectite and chlorite-smectite, and kaolinite among the phyllosilicates. We have determined their structural and crystal-chemical features and quantitative proportions in the section (800 cm long core), which vary in accordance with the climate cycles and lake level fluctuations. The results obtained helped to reconstruct the evolution of the Lake Baunt basin controlled by the regional climate throughout the Late Pleistocene-Holocene. This paper continues a series of our publications concerned with the reconstruction of the Late Pleistocene-Holocene climate in East Siberia by comprehensive studies of the mineral composition of sedimentary sections of small lakes. [ABSTRACT FROM AUTHOR]

Flood risk in Siberia increased in recent years. This is most often associated with two main reasons: global climate change, and the increase in economic development in territories at risk of flooding and resulting human impacts on river basins. We tried to bring new data and results on this topic. The objective of this paper is to assess the change in the hydrological regime under climatic changes and the dynamics of flood recurrence on the river basins of southern East Siberia in the latter half of the 20th and the beginning of the 21st century. We used information on run-off and water levels obtained from hydrological stations of the Irkutsk and Ulan-Ude Administration for Hydrometeorology and Environmental Monitoring. The annual and monthly mean run-off data series were subjected to statistical analysis. Linear trends and their significance were evaluated in general for the identical period from 1961 to 2006 at 37 gauging stations. Flood recurrence in the Angara and Lena river basins was calculated for two periods - before the expressed climatic changes (1960-1979) and for the expressed climatic changes (1980-2005). In general, the value of the annual run-off was unchanged. The intra-annual redistribution of run-off occurs, showing a reduction in the run-off from spring snowmelt and an increase in run-off for the autumn - winter low water period. Intra-annual run-off redistribution under climatic changes does not provoke an increase in extreme conditions. The analysis of flood recurrences showed no significant changes in the mean recurrence in basins. However, there was either a significant increase or decrease in the number of floods for some gauging stations. Remote sensing data were used to analyse the dynamics of human impact on such river basins. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Climate changes influence seasonal tree-ring formation. The result is a specific cell structure dependent on internal processes and external environmental factors. One way to investigate and analyze these relationships is to apply diverse simulation models of tree-ring growth. Here, we have proposed a new version of the VS-Cambium-Developer model (VS-CD model), which simulates the cambial activity process in conifers. The VS-CD model does not require the manual year-to-year calibration of parameters over a long-term cell production reconstruction or forecast. Instead, it estimates cell production and simulates the dynamics of radial cell development within the growing seasons. Thus, a new software based on R programming technology, able to efficiently adapt to the VS model online platform, has been developed. The model was tested on indirect observations of the cambium functioning in Larix sibirica trees from southern Siberia, namely on the measured annual cell production from 1963 to 2011. The VS-CD model proves to simulate cell production accurately. The results highlighted the efficiency of the presented model and contributed to filling the gap in the simulations of cambial activity, which is critical to predicting the potential impacts of changing environmental conditions on tree growth. [ABSTRACT FROM AUTHOR]

Boreal forest ecosystems are regions vulnerable to climate change. Such areas act as the main atmospheric carbon sinks in the world. Wildfires are among the drivers of ecosystem modification and functioning. Boreal wildfires emit an annual average of about 10% of global fire emissions. Taking into account recent climate warming and increases in the frequency of wildfires, boreal forests might switch their functional role from carbon sink to an additional source of atmospheric carbon. Soil respiration is the second largest component of the global carbon cycle and is highly sensitive to disturbance factors, including wildfires. To study the effect of wildfires on soil CO2 emission rates, the fire chronosequence was investigated. During the first few years following the fire, the soil CO2 emission rates were lower compared with the usual levels. It was found that 23 years after a fire, the site demonstrated transition behavior in soil emission rates between disturbed and completely recovered areas. The emission rates at the earliest successional stages are mainly controlled by soil moisture during the summer period. For the other successional stages, soil temperature had a huge impact on soil emission. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change threatens northern permafrost environments. This compromises the existence of permafrost landforms, such as palsas and peat plateaus, which have been assessed to be critically endangered habitats. In this study, we integrated geospatial datasets and statistical methods to model the suitable environments for palsas and peat plateaus across the Northern Hemisphere permafrost region. The models were calibrated using data from years 1950–2000. The effects of climate change on the suitable environments for the landforms were assessed by using low-, moderate-, and high-emissions scenarios (Representative Concentration Pathway climate scenarios: RCP2.6, RCP4.5, and RCP8.5, respectively) for two periods (2041–2060 and 2061–2080). Hotspots for palsa and peat plateau environments occurred in northern Europe, western Siberia, and subarctic Canada. Climate change was predicted to cause an almost complete loss (decrease of 98.2 %) of suitable environmental spaces under the high-emissions scenario by 2061–2080, while under low- and moderate-emissions scenarios the predicted loss was 76.3 % and 89.3 % respectively. Our modeling results are in line with previously published thermokarst data pointing out areas of recent degradation of palsa and peat plateau environments. Our results provide new insights into the distribution of the permafrost landforms in less studied areas such as central and eastern Siberia. In addition, the predictions provide new understanding of the changing geoecological conditions of the circumpolar region with important implications for greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Climate change and climate-sensitive disasters caused by climatic hazards have a significant and increasing direct and indirect impact on human health. Due to its vast area, complex geographical environment and various climatic conditions, Russia is one of the countries that suffers significantly from frequent climate hazards. This paper provides information about temperature extremes in Russia in the beginning of the 21st century, and their impact on human health. A literature search was conducted using the electronic databases Web of Science, Science Direct, Scopus, and e-Library, focusing on peer-reviewed journal articles published in English and in Russian from 2000 to 2021. The results are summarized in 16 studies, which are divided into location-based groups, including Moscow, Saint Petersburg and other large cities located in various climatic zones: in the Arctic, in Siberia and in the southern regions, in ultra-continental and monsoon climate. Heat waves in cities with a temperate continental climate lead to a significant increase in all-cause mortality than cold waves, compared with cities in other climatic zones. At the same time, in northern cities, in contrast to the southern regions and central Siberia, the influence of cold waves is more pronounced on mortality than heat waves. To adequately protect the population from the effects of temperature waves and to carry out preventive measures, it is necessary to know specific threshold values of air temperature in each city. [ABSTRACT FROM AUTHOR]

Western Siberia contains extensive wetlands and aquatic ecosystems, contributing a significant amount of methane (CH4) emissions to the atmosphere. However, estimates of CH4 fluxes over the region are poorly constrained partly due to the uncertainties from the inundated area data. This study applied two process‐based biogeochemistry models to quantify the emissions from land and aquatic ecosystems over the region within the period 2000–2021 using different inundation datasets. To drive land methane modeling, we use one static wetland map and one dynamic wetland area data set called Wetland Area and Dynamics for Methane Modeling (WAD2M) (2000–2020). To drive lake methane modeling, we use the surface area of aquatic ecosystems from three datasets: (a) HydroLAKES; (b) Global Surface Water (GSW); and (c) surface water inundation from Soil Moisture Active Passive (SMAP) (2016–2021). Using these datasets, we conduct four simulations to compare emissions over the region. We find that the net methane emissions from land using the static wetland map are larger than those using WAD2M. SMAP and GSW estimate larger emissions than HydroLAKES does from aquatic ecosystems. Total emissions over the region range from 4.80 ± 0.43 to 8.29 ± 0.81 Tg CH4/year from 2016 to 2020, which is the intersection period of four simulations. This study is among the first to investigate methane emissions from the whole landscape in the region. Our study highlights the importance of dynamic wetland and aquatic area data in quantifying regional methane emissions. Plain Language Summary: Methane (CH4) is a vital greenhouse gas that can make large differences in global climate change. In this study, we quantified total methane emissions over Western Siberia, which is a methane‐emitting hotpot. We used two process‐based models to quantify methane emissions from both land and aquatic ecosystems over the region. We used different combinations of wetlands and aquatic areal datasets to run four model simulations for comparison. We found that the total emissions over the region range from 4.80 ± 0.43 to 8.29 ± 0.81 Tg CH4/year from 2016 to 2020 depending on the land and aquatic areal dynamics. We conclude that it is important to develop dynamic wetland and aquatic area data in quantifying regional methane emissions. Key Points: Methane emissions from both land and aquatic ecosystems over Western Siberia are quantifiedTotal methane emissions over Western Siberia range from 4.80 ± 0.43 to 8.29 ± 0.81 Tg CH4/year from 2016 to 2020It is important to develop both dynamic wetland and aquatic area data in quantifying regional methane emissions [ABSTRACT FROM AUTHOR]

Correct simulation of land surface energy balance is critically important in reliably projecting future climate change. In this study, simulated surface energy fluxes including net radiation, latent heat, and sensible heat from 22 CMIP6 models are evaluated against ERA5 reanalysis data during 1950–2014 over global land surface to assess the performance of CMIP6 models in simulating surface energy balance. Results reveal significant differences in seasonal and regional characteristics of CMIP6 model simulations in the surface energy flux predictions. Net radiation is slightly overestimated in JJA (June, July, August) but underestimated in DJF (December, January, and February). Most models overestimate net radiation in both seasons over Africa, Australia, and Latin America. The inter-model variability of biases is substantial in DJF net radiation simulations over Asia, Europe and Siberia, and North America, although there is a good agreement between simulations of selected models and the ERA5 reanalysis data in JJA except for Greenland. Moreover, models overestimate latent heat and underestimate sensible heat in DJF, although latent heat and sensible heat simulations match well with the reference values in JJA. Latent heat is overestimated in DJF over Australia, Europe and Siberia, and Latin America. Sensible heat is underestimated during DJF over Europe and Siberia and Latin America. The performance of CMIP6 in Rn simulation is better than LH simulation and SH simulation for both JJA and DJF. Findings from this study will provide useful references for surface energy data users and future model development. [ABSTRACT FROM AUTHOR]

In the context of global climate change, the extent of snow cover in Siberia has significantly decreased since the 1970s, especially in spring. The changes of snow cover at middle and high latitudes have significant impacts on the meteorological and hydrological processes because the snow cover can affect the surface energy, water balance, and the development of the atmospheric boundary layer. In this paper, the temporal and spatial changes in snow cover were firstly estimated based on a long time series of remote sensing snow cover data, both showing a decreased trend. Based on this, we estimated the radiative forcing caused by the snow cover changes from the 1970s to the 2010s and compared it with the radiative forcing caused by the vegetation cover changes over the same time period in Siberia, indicating that the snow cover changes in Siberia can accelerate climate warming and the vegetation cover changes here have the opposite effect. Furthermore, the snow cover changes may play a more important role than the vegetation cover changes in regulating the surface radiation balance in Siberia on the regional scale. [ABSTRACT FROM AUTHOR]

The availability of clean drinking water impacts the quality of life of Arctic populations and is affected by climate change. We provide perceptions based on: (1) a study of the accessibility of the natural surface water to the nomadic and settled Indigenous inhabitants living in rural areas (in settlements and remote camps) in the Arctic zone of Western Siberia during climate change and industrial development; (2) an assessment of the impact of consuming different surface water resources on human health. We include primary data sources from medical examinations and surveys collected in the regions between the rivers of Ob, Nadym, Taz, and Yenisey in 2012, 2014–2019, and 2022 whereas the chemical analysis of the surface waters in the region was based on previous research. A total of 552 local residents from the Arctic zone of Western Siberia participated in the study. We discuss how the availability of high-quality drinking water is limited for them due to climatic and anthropogenic risks, despite the abundant water resources. The consumption of river water is associated with high health risks since it contains heavy metals (Pb, Cd, Mn, Fe), whereas the consumption of lake ice melt water likely affects health because of the low concentrations of beneficial ions. [ABSTRACT FROM AUTHOR]

Current climatic trends raise concerns about the fate of boreal forests and associated communities. To understand forest vegetation dynamics in the face of future changes, it is necessary to know how trees have responded to past climatic fluctuations. We investigated genetic data and a past distribution based on paleorecords and species distribution modeling data to determine refugia and migration routes of Siberian stone pine (Pinus sibirica) from the late Pleistocene to the present. Thus, we gained a deep insight into the past of Siberian stone pine. We revealed four genetic clusters of Siberian stone pine located in the following mountain systems of Siberia: the West Sayan and the Altai (WSA), the East Sayan (ES), the Kuznetsk Alatau (KA), and the Urals (U). Paleorecords and species distribution modeling indicated preservation of Siberian stone pine in these mountains and near big lakes (Lake Baikal and Lake Teletskoe) during the Last Glacial Maximum (LGM). Nonetheless, processes of migration from these refugia were heterogeneous: WSA has never expanded after the LGM beyond its current range; ES occupied the eastern geographic range of the species; KA and U had common history before the LGM and got isolated during LGM. Moreover, refugia and migration routes of Siberian forest species (Larix sibirica and Abies sibirica) were different from those of P. sibirica despite similar ecological preferences. Pinus sibirica occupied the West Siberian Plain from the Urals and Kuznetsk Alatau, whereas A. sibirica and L. sibirica expanded from Lake Baikal and the Sayan Mountains, respectively. Thus, our results substantially complement existing notions of South Siberia Mountains, Lake Baikal area, and Urals as glacial refugia for Siberian stone pine. [ABSTRACT FROM AUTHOR]

Global climate change might result in permafrost thaw and the formation of thermokarst landscapes that release long-term carbon stocks as greenhouse into the atmosphere, thereby initiating a positive climate feedback. These processes are mediated by biological activity, including by microbes, vascular plants and animals, whereas the role of invertebrates in thermokarst ecosystems remains poorly understood. We investigated the diversity and assemblage structures of zooplankton (mainly Copepoda, Cladocera), microbenthos (testate amoebae) and meio- (Copepoda and Cladocera) and macrozoobenthos (mollusks, crustaceans, insects and annelids) from a range of water bodies representing different stages of thermokarst lake formation in the southern part of the Lena River Delta (Central Siberia). Altogether, 206 species of testate amoeba, mollusk, crustacean, insect and annelid taxa were identified. A total of 60 species of macrozoobenthos (mainly insects) and 62 species of testate amoebae were detected in the water bodies of the Lena River Delta for the first time. The species richness of zooplankton and meio- and macrozoobenthos was greater in the large thermokarst lakes than in the polygonal ponds due to the freezing of the latter in the winter. In contrast, the species richness of protists was higher in the polygonal ponds, which was related to the habitat preferences of testate amoebae. Fish grazing strongly affected the macrobenthos assemblages but not the smaller-sized organisms. Water acidity and temperature were the main environmental drivers of the assemblage structure of testate amoeba and microcrustacean. The species structure of the macroinvertebrate assemblages was significantly explained by water acidity, permafrost depth and size of the water area. It means that small size organisms with their short generation times are sensitive to more dynamic factors such as temperature and may serve as indicators of ecosystem changes due to global climate warming. In contrast, large size organisms are affected by driven factors that appear during thermokarst lakes formation and permafrost degradation. [ABSTRACT FROM AUTHOR]

Detailed studies of processes of sediment-record formation are necessary for accurate sediment-derived paleo environmental reconstructions. In order to understand the deposition of sediments in meromictic Lake Shira (southern Siberia, Russia), we conducted a multi-year seasonal sediment trap study of sediment fluxes of chemical elements, organic and inorganic carbon, total nitrogen and photosynthetic pigments for a period from 2012 to 2017. In 2015 and 2016, a rare event of transition from meromixis (i.e. long-term hypolimnetic anoxia) to holomixis was observed, which was accompanied by the temporary disappearance of hydrogen sulfide from the water column in spring and a decrease in hydrogen sulfide in other seasons compared to the meromictic state. In general, we did not reveal any noticeable differences between the meromictic and holomictic states in the composition of sediments, except for okenone. The content of okenone, a specific carotenoid of purple sulfur bacteria, decreased in traps during the holomictic state and did not considerably increase two years after the meromixis restoration. Using a freeze-corer, we observed that the content of okenone in the uppermost 3-mm layer of sediments also decreased markedly from 2013 to 2017, as well as in traps. The sedimentation flux of molybdenum reflected the seasonality of hydrogen sulfide content in the water column, and it was maximal in winter, in contrast to all other sediment components. Other components reflected the seasonality of organic production and terrigenous inputs, with the maximum in late summer and autumn. An increase in the sedimentation rate of terrigenous elements in the autumn of 2012 was supposedly caused by the anomalous amount of precipitation in August 2012. Since detailed inter-annual observations of sedimentation processes are not often found in limnology, we hope that our results will be useful for reconstructing regional climate and, further, the understanding of sediment dynamics of stratified temperate water bodies. [ABSTRACT FROM AUTHOR]

Fritillaria Tourn. ex L. is a genus of Liliaceae including a little more than 150 species occurring in the temperate Holarctic. Fritillaria sonnikovae Shaulo & Erst is the most recently described Siberian species in the genus. In the affinity section of the F. sonnikovae diagnosis, only F. dagana Turcz. and F. roylei Hook. are mentioned. Our study is an original attempt to shed light on the F. sonnikovae origin and its evolutionary relationships with other Fritillaria using nuclear (ITS) and plastid (matK + rps16 + trnH-psbA) DNA markers. Our results showed that F. sonnikovae together with F. dagana and F. maximowiczii Freyn belongs to the North Asian lineage of the Liliorhiza subgenus and produced no evidence supporting relationship between F. sonnikovae and F. roylei. Monophyly of Fritillaria sonnikovae was not reliably confirmed in our study since its close affinity with F. maximowiczii was demonstrated by phylogenetic analysis and morphology. Fritillaria dagana was shown to be a sister to the F. maximowiczii + F. sonnikovae group. Most authors of the present study suggest considering F. sonnikovae as a synonym for F. maximowiczii. In this view, F. sonnikovae may be considered a narrow endemic and one of the light-perianth morphs of F. maximowiczii, which has emerged in the Western Sayan and remained there as a tertiary relict. [ABSTRACT FROM AUTHOR]

Aim: To determine the ecological processes and drivers of range collapse, population decline and eventual extinction of the steppe bison in Eurasia. Location: Siberia. Time period: Pleistocene and Holocene. Major taxa studied: Steppe bison (Bison priscus). Methods: We configured 110,000 spatially explicit population models (SEPMs) of climate–human–steppe bison interactions in Siberia, which we ran at generational time steps from 50,000 years before present. We used pattern‐oriented modelling (POM) and fossil‐based inferences of distribution and demographic change of steppe bison to identify which SEPMs adequately simulated important interactions between ecological processes and biological threats. These "best models" were then used to disentangle the mechanisms that were integral in the population decline and later extinction of the steppe bison in its last stronghold in Eurasia. Results: Our continuous reconstructions of the range and extinction dynamics of steppe bison were able to reconcile inferences of spatio‐temporal occurrence and the timing and location of extinction in Siberia based on hundreds of radiocarbon‐dated steppe bison fossils. We showed that simulating the ecological pathway to extinction for steppe bison in Siberia in the early Holocene required very specific ecological niche constraints, demographic processes and a constrained synergy of climate and human hunting dynamics during the Pleistocene–Holocene transition. Main conclusions: Ecological processes and drivers that caused ancient population declines of species can be reconstructed at high spatio‐temporal resolutions using SEPMs and POM. Using this approach, we found that climatic change and hunting by humans are likely to have interacted with key ecological processes to cause the extinction of the steppe bison in its last refuge in Eurasia. [ABSTRACT FROM AUTHOR]

Climate change has become an important cause of the loss of bird habitat and changes in bird migration and reproduction. The lesser white-fronted goose (Anser erythropus) has a wide range of migratory habits and is listed as vulnerable on the IUCN (International Union for Conservation of Nature) Red List. In this study, the distribution of suitable breeding grounds for the lesser white-fronted goose was assessed in Siberia, Russia, using a combination of satellite tracking and climate change data. The characteristics of the distribution of suitable breeding sites under different climate scenarios in the future were predicted using the Maxent model, and protection gaps were assessed. The analysis showed that under the background of future climate change, temperature and precipitation will be the main climatic factors affecting the distribution of breeding grounds, and the area associated with suitable breeding habitats will present a decreasing trend. Areas listed as an optimal habitat only accounted for 3.22% of the protected distribution; however, 1,029,386.341 km2 of optimal habitat was observed outside the protected area. Obtaining species distribution data is important for developing habitat protection in remote areas. The results presented here can provide a basis for developing species-specific habitat management strategies and indicate that additional attention should be focused on protecting open spaces. [ABSTRACT FROM AUTHOR]

Climatic variations have impacted societies since the very beginning of human history. In order to keep track of climatic changes over time, humans have thus often closely monitored the weather and natural phenomena influencing everyday life. Resulting documentary evidence from archives of societies enables invaluable insights into the past climate beyond the timescale of instrumental and early instrumental measurements. This information complements other proxies from archives of nature, such as tree rings in climate reconstructions, as documentary evidence often covers seasons (e.g., winter) and regions (e.g., Africa, eastern Russia, Siberia, China) that are not well covered with natural proxies. While a mature body of research on detecting climate signals from historical documents exists, the large majority of studies is confined to a local or regional scale and thus lacks a global perspective. Moreover, many studies from before the 1980s have not made the transition into the digital age and hence are essentially forgotten. Here, I attempt to compile the first-ever systematic global inventory of quantitative documentary evidence related to climate extending back to the Late Medieval Period. It combines information on past climate from all around the world, retrieved from many studies of documentary (i.e., written) sources. Historical evidence ranges from personal diaries, chronicles, and administrative and clerical documents to ship logbooks and newspaper articles. They include records of many sorts, e.g., tithe records, rogation ceremonies, extreme events like droughts and floods, and weather and phenological observations. The inventory, published as an electronic Supplement, is comprised of detailed event chronologies, time series, proxy indices, and calibrated reconstructions, with the majority of the documentary records providing indications on past temperature and precipitation anomalies. The overall focus is on document-based time series with significant potential for climate reconstruction. For each of the almost 700 records, extensive meta-information and directions to the data (if available) are given. To highlight the potential of documentary data for climate science, three case studies are presented and evaluated with different global reanalysis products. This comprehensive inventory promotes the first ever global perspective on quantitative documentary climate records and thus lays the foundation for incorporating documentary evidence into climate reconstruction on a global scale, complementing (early) instrumental measurements and natural climate proxies. [ABSTRACT FROM AUTHOR]

High resolution palaeoenvironmental records in Far-Eastern Russia are rare, and the Kamchatka Peninsula is among the least studied areas of the region. This paper describes a record spanning the last ca. 11,000 yr, obtained from a bog in the southern part of Kamchatka. The radiocarbon dated core was analysed for pollen, testate amoebae, charcoal and loss-on-ignition (LOI). The vegetation during the early Holocene was dominated by grasses (Poaceae), birch ( Betula ) and heath (Ericaceae p. p.). Around 10,300 cal yr BP there was a substantial change in the vegetation cover to shrub alder ( Alnus viridis s.l.) stands with sedges and ferns (Polypodiophyta) as well as herbs such as meadow rue ( Thalictrum ) in the understory. In the surroundings of Utka peatlands started to form. The variations in the vegetation cover were most probably caused by climatic changes. At the beginning of sediment accumulation, before 10,300 cal yr BP, the composition of the vegetation points to cooler summers and/or decreased annual precipitation. Around 10,300 cal yr BP, changes in vegetation occurred due to rising temperatures and/or changed water regimes. Increased abundancies of dry indicating testate amoebae after 9100 cal yr BP point to intermediate to dry soil conditions. Between 8600 and 7700 cal yr BP tree alder ( Alnus incana ) was widely spread at the site which probably indicates optimal environmental conditions. The tephra layer at 381–384.5 cm (ca. 8500 cal yr BP) produces a strong impact on the testate amoebae assemblages. At 7700 cal yr BP there was a sudden drop of A. incana in the local vegetation. From this time on, A. incana and also A. viridis decrease continuously whereas Betula gradually increases. The upper part of the sequence (after 6300 cal yr BP) shows higher abundancies of meadowsweet ( Filipendula ) and sweet gale ( Myrica ) pollen. After 6300 cal yr BP, changes in testate amoebae demonstrate variable soil moisture conditions at the site. Between 3700 and 1800 cal yr BP, wet conditions dominate as dry indicating testate amoebae decrease. After 1800 cal yr BP soil conditions become more variable again but this time with dry dominating testate amoebae. In contrast to surrounding regions, there is no evidence of trees such as spruce or larch growing in the surroundings of the site even though those trees are characteristic of many eastern Siberian sites. This difference might be because of the maritime influence of the Okhotsk Sea. Even dwarf pine ( Pinus pumila ), which is currently widely dispersed in northern Kamchatka, became part of the local vegetation only during the last 700 yr. [ABSTRACT FROM AUTHOR]

Eranthis Salisb. (Ranunculaceae) is a herbaceous plant genus, including few species disjunctively distributed throughout the temperate zone from Southeastern Europe to Eastern Asia. Until recently, only Eranthis sibirica DC. was known in South Siberia, being considered endemic and tertiary relict. Not long ago, Eranthis tanhoensis Erst was also described in Siberia. We report here a reconstruction of the phylogenetic relationships between the Siberian Eranthis species based on nuclear (ITS) and plastid (trnL + trnL-trnF + trnH-psbA) DNA. The phylogeographic structure of Siberian Eranthis is distinguished by the presence of the two "eastern" and "western" supergroups, which most likely formed as a result of disjunction caused by active mountain uplifts during the late Neogene–early Quaternary and subsequent progressive Pleistocene cooling. The eastern supergroup combines lineage I, containing populations from the eastern Khamar-Daban Ridge, the Eastern Sayan Mountains, and the Tannu-Ola Ridge, and lineage II containing western Khamar-Daban populations. The western supergroup includes only lineage III, containing Western Sayan populations. Our data clearly show that E. tanhoensis is nested in the E. sibirica clade, thereby indicating that its description as a separate species is unjustified, as it compromises the monophyletic status of E. sibirica. Therefore, we suggest here to consider E. tanhoensis as a synonym of E. sibirica. [ABSTRACT FROM AUTHOR]

The sections of the boundary Jurassic–Cretaceous black shale sediments (Bazhenov Formation) of the West Siberian sedimentary basin in conditional Central, Southeastern, and Northern regions are compared on the basis of a complex lithological-geochemical study, as well as geophysical and paleontological data. The studies are conducted using a common classification scheme of rocks and common principles of recognition of members in the structure of the formation. The elaborated sedimentation models reflect the spatiotemporal principles of the origination of the Bazhenov Formation depending on the features of paleotopography, proximity to the provenances, climatic fluctuations, and changes in sea level. The Central region was mostly characterized by biogenic siliceous sedimentation (radiolarian or similar sediments) during the entire Volgian Stage (locally, to the beginning of the Ryazanian Stage) and by carbonate-siliceous sedimentation (coccolith-rich sediments) from the end of the Volgian Stage to the beginning of the early Valanginian, which was favorable for the accumulation of a significant amount of organic matter. The accumulation of carbonate-siliceous sediments finished by the middle of the Ryazanian Stage within the Khantei Hemianteclise and the southeastern part of the South Nadym Megamonoclise of the Central region. In the Southeastern region, the formation of organic-rich sediments terminated at the stage of accumulation of biogenic-siliceous silts and, from the beginning of the Ryazanian Stage, was followed by sedimentation of organic-poor clays of the Megion and Kulomzino formations. The Northern region was characterized by the accumulation of relatively organic-poor siliceous-argillaceous sediments with a dominant terrigenous (over biogenic) component by means of more intense gain of clay material to this zone of the paleobasin. The sedimentation of the Bazhenov Formation here was probably terminated in the first half of the Ryazanian Stage. [ABSTRACT FROM AUTHOR]

Boreal fires considerably influence carbon release and air quality, but its occurrence mechanisms need to be explored. This study investigated the influence of winter North Atlantic sea surface temperature (SST) on spring Eurasian wildfire using single value decomposition method. Two possible pathways link such time‐lag phenomena. The anomalous SST pattern in winter can persist to spring, resulting in a significant high air‐pressure anomaly over southeastern Siberia, which corresponds to less‐than‐normal precipitation and enhanced aridity conditions and the increasing wildfire risk. Meanwhile, there are simultaneously negative snow cover anomalies over southeastern Siberia during winter which is closely related to the winter SSTs. Such snow anomalies persist from winter to spring, leading to negatively anomalous soil moisture. Both pathways provide a favorable environment for wildfire activities. This study implies that the winter North Atlantic SST could be a robust driver and potential precursor for spring wildfire prediction over southeastern Siberia. Plain Language Summary: The Atlantic Ocean is one of the most sensitive regions for global climate change, and its sea surface temperature (SST) can affect the planetary‐scale circulation in the Northern Hemisphere, subsequently influence the Eurasian climate. The tripole structure is an important mode of the North Atlantic SST interannual variability, characterized by positive (negative) SST anomalies in the midlatitude and tropical North Atlantic and negative (positive) SST anomalies in the subtropical North Atlantic. However, the relationship between the anomalous North Atlantic SST and Eurasian wildfire changes is not well understood. Here we found spring wildfire in southeastern Siberia significantly increased associated with the negative‐positive‐negative meridional pattern of the winter North Atlantic SST. The winter North Atlantic tripole pattern could persist to the following spring, leading to warmer temperature and less precipitation over the southeastern Siberia, thus more serious aridity condition. In addition, such anomalous winter SST causes snowfall decreasing in the southeastern Siberia, which reduces spring soil moisture and increases the aridity risk. The two pathways associated with the anomalous North Atlantic SST enhance wildfire in the southeastern Siberia. Key Points: There is a significant covarying mode between the tripole pattern of the winter North Atlantic sea surface temperature (SST) and spring wildfire over the EurasiaPrecipitation and soil moisture are the main intermediate factors linking SST and large‐scale wildfireThe winter SST modulates spring precipitation and soil moisture by persistence of the SST tripole pattern and snow cover anomaly [ABSTRACT FROM AUTHOR]

Mass livestock mortality events during severe winters, a phenomenon that Mongolians call dzud, cause the country significant socioeconomic problems. Dzud is an example of a compound event, meaning that multiple climatic and social drivers contribute to the risk of occurrence. Existing studies argue that the frequency and intensity of dzud events are rising due to the combined effects of climate change and variability, most notably summer drought and severe winter conditions, on top of socioeconomic dynamics such as overgrazing. Summer droughts are a precondition for dzud because scarce grasses cause malnutrition, making livestock more vulnerable to harsh winter conditions. However, studies investigating the association between climate and dzud typically look at a short time frame (i.e., after 1940), and few have investigated the risk or the recurrence of dzud over a century-scale climate record. This study aims to fill the gaps in technical knowledge about the recurrence probability of dzud by estimating the return periods of relevant climatic variables: summer drought conditions and winter minimum temperature. We divide the country into three regions (northwest, southwest, and east Mongolia) based on the mortality index at the soum (county) level. For droughts, our study uses as a proxy the tree-ring-reconstructed Palmer drought severity index (PDSI) for three regions between 1700–2013. For winter severity, our study uses observational data of winter minimum temperature after 1901 while inferring winter minimum temperature in Mongolia from instrumental data in Siberia that extend to the early 19th century. Using a generalized extreme value distribution with time-varying parameters, we find that the return periods of drought conditions vary over time, with variability increasing for all the regions. Winter temperature severity, however, does not change with time. The median temperature of the 100-year return period for winter minimum temperature in Mongolia over the past 300 years is estimated as -26.08 ∘ C for the southwest, -27.99 ∘ C for the northwest, and -25.31 ∘ C for the east. The co-occurrence of summer drought and winter severity increases in all the regions in the early 21st century. The analysis suggests that a continued trend in summer drought would lead to increased vulnerability and malnutrition. Prospects for climate index insurance for livestock are also discussed. [ABSTRACT FROM AUTHOR]

This paper presents a new palynological record from a 146 cm long finely laminated sediment core obtained in 2009 from the deep-water meromictic Lake Shira (54°30′38″N, 90°12″09′E; ca. 353 m a.s.l.) situated in the Khakassian steppe region of southern Siberia between the rivers Ob' and Yenisei. The area is rich in lakes and represents an exceptionally well preserved sequence of Bronze and Iron Age archeological cultures. Little is known about the changes in vegetation and climate of the region during the Holocene. The palynological analysis of the core allows us to partly fill up this gap in current knowledge. The record of pollen and non-pollen palynomorphs presented here covers the past 2450 year interval with an average resolution of 22 years. The results obtained support the interpretation that the late Holocene vegetation changes around Lake Shira are mainly associated with large-scale atmospheric circulation processes controlling the regional water balance rather than with human activities. An attempt to trace human impact in the pollen assemblages provides no clear evidence for anthropogenic activity, except for the last few decades since ca. 1955, though the region has a long history of mobile pastoralists. For explanation of decadal-scale changes in the regional vegetation cover, the Artemisia /Chenopodiaceae (A/C) pollen ratio proved to be a reliable indicator of effective moisture availability. Using available fossil and published instrumental data our study suggests a link between the North Atlantic warmer/colder temperatures and higher/lower atmospheric precipitation (or moisture availability) in southern Siberia at multi-decadal to centennial scales. [ABSTRACT FROM AUTHOR]

A detailed, well‐dated record of pollen and sedimentary ancient DNA (sedaDNA) for the period 15 000–9500 cal a bp describes changes at Lake Bolshoye Shchuchye in the Polar Ural Mountains, located far east of the classical Lateglacial sites in western Europe. Arctic tundra rapidly changed to lusher vegetation, possibly including both dwarf (Betula nana) and tree birch (B. pubescens), dated in our record to take place 14 565 cal a bp, coincident with the onset of the Bølling in western Europe; this was paralleled by increased summer temperatures. A striking feature is an early decline in Betula pollen and sedaDNA reads 300 years before the onset of the Younger Dryas (YD) in western Europe. Given the solid site chronology, this could indicate that the YD cooling started in Siberia and propagated westwards, or that the vegetation reacted to the inter‐Allerød cooling at 13 100 cal a bp and did not recover during the late Allerød. During the YD, increases in steppe taxa such as Artemisia and Chenopodiaceae suggest drier conditions. At the onset of the Holocene, the vegetation around the lake reacted fast to the warmer conditions, as seen in the increase of arboreal taxa, especially Betula, and a decrease in herbs such as Artemisia and Cyperaceae. [ABSTRACT FROM AUTHOR]

Publications on changes in river water regime in Russia under the conditions of current climate changes are reviewed. Most recent generalizations of such publications are presented in Roshydromet evaluation reports. The publication of these basic studies followed by many studies improving the conclusions of national reports. The objective of this review is to generalize the current concepts regarding the effect of climate changes in Russian Federation territory on the mean annual and maximal river runoff, primarily, based on most recent publications and the authors' own studies. New maps, developed by the authors, are given to characterize variations of the annual and maximal runoff, including the dates of the disturbance of the stationary character of the series based on data up to 2019. Considerable attention is paid to statistical analysis of the revealed changes. The annual runoff on the average for the Russian territory is shown to tend to increase in the recent decades because of an increase in the moistening of the territory. However, the changes in the majority of the analyzed basins are statistically insignificant. The average annual runoff of rivers into the Arctic seas from the territory of Siberia and Far East has also slightly increased. Changes in the maximal runoff are more pronounced and differently directed. [ABSTRACT FROM AUTHOR]

Summary: In this article, I explore the relationship of Sakha, horse and cattle pastoralists of northeastern Siberia, and alaas, permafrost ecosystems that Sakha depend on for their subsistence. I show that this relationship is both physical and spiritual. In a time of climate change, alaas are changing due to the thawing permafrost, making them unusable for Sakha people. I argue that we must consider and accommodate the reverberations of such change for a people who are gradually losing a recognizable landscape central to their cultural identity. These questions are highly relevant for anthropologists working with the diversity of cultures challenged by similar "dislocations" from their known places, relevant environments, and core sources of their cultural identities. Such investigations are essential to effective global change research, revealing how engaging all relevant knowledge systems counters the hegemony of scientific knowledge and moves toward more equitable and just adaptation responses and policy prescriptions. [ABSTRACT FROM AUTHOR]

Understanding the variations of the westerly jets (WJs) during the Last Interglacial (~ 127 ka; LIG) aids in deciphering the reconstructed hydrological conditions and dust activities at that time. Here, we investigated variations of the WJs over the Northern Hemisphere during the LIG based on the Paleoclimate Modelling Intercomparison Project 4. We demonstrated that WJs exhibited divergent responses across regions and seasons during the LIG. In summer, WJs over the African–Asian–Pacific regions moved poleward by ~ 5° and weakened by 19% during the LIG, whereas there was only a slight change (+ 1°/− 2%) over the North American–Atlantic regions. In contrast, the winter WJs over the North American–Atlantic regions shifted poleward by ~ 2° and weakened by 7%, but with no obvious responses (− 0.2°/− 0.8%) over the African–Asian–Pacific regions. The WJs variations were linked to changes in meridional temperature gradients and maximum eddy growth rates. Furthermore, the poleward shift and weakening of the WJs over the East Asian–Pacific regions in summer resulted from the anomalous anticyclone triggered by the deep warm center over East Siberia and the anomalous cyclone linked with diabatic cooling over the western tropical Pacific. For the poleward-displaced and depressed WJs over the North American–Atlantic regions in winter, the propagation of Rossby waves from the eastern Pacific played a more important role, compared with the effect of tropical heating. Our work highlights divergent responses of the WJs to orbital forcing during the LIG, which helps to decipher the reconstructed westerlies-related processes and hence to obtain a better understanding of the climate change during this orbitally induced warm period. [ABSTRACT FROM AUTHOR]