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Based on the palynological analysis of the bottom sediment column of the arctic lake with the code name K1 of the Yerkuta river basin from the southwestern part of the Yamal Peninsula, we received a preliminary information on climatic changes, as well as on changes in vegetation character in the area around the water body. Reconstruction of vegetation around the lake has identified the development of a brush-grass-moss tundra. Shrubs are represented by Betula sect. Nana, Alnaster, Salix sp., Ericaceae. Herbaceous ...

In this study, variations in the paleoecological conditions of Western Siberia were analyzed. For the paleoecological studies, a core of bottom sediments, 51 cm long, was taken from an unnamed lake located in the Yamalo-Nenets Autonomous Okrug. A total of 26 samples from the core were examined in detail. As a result, 30 cladoceran taxa were registered. Among them, Bosmina (Eubosmina) longispina was dominant throughout the core. The subdominant species were Alonella nana and Chydorus cf. sphaericus from the family ...

This investigation is aimed to determine the general development phases of the vegetation and climatic situations of the Pur-Taz interfluvial region, Western Siberia (Yamalo-Nenets Autonomous Okrug, Russia) based on the spore-pollen analysis of the bottom sediments of the Lake 17-Ya-01. The palynological analysis was carried out on the basis of 26 samples. In total, 26 palynomorphs have been identified. A spore-pollen diagram, which has been divided on the 4 biostratigraphic sequences (pollen zones PZ I-IV), refle...

For the Arctic region of Russia, an inventory of the biodiversity of aquatic ecosystems for the purpose of environmental monitoring is extremely urgent. Global warming for terrestrial ecosystems manifest as changes in the distribution of individual species and assemblages, in the timing of important life-cycle events, and in abundance and community structure. Zooplankton communities in the Northern lakes are highly diverse and thus perform a variety of ecosystem functions. The most important role of zooplankton is...

Russian Arctic regions are most sensitive to global climate change. Their unique and fragile ecosystems are very dependent on freshwater. Beyond temperature rise, climate change is accompanied by shifts in precipitation and wind conditions, thereby causing floods, droughts, and altered mixing regimes, all having a serious impact on the abiotic and biotic structure. This work is relevant for better understanding of the biota of the Russian Arctic. Cladocerans are very promising for studying climate change risks owi...

Diatoms are widely used for paleoindication, through which the main stages of life of lakes against the background of changing environmental conditions determined by both natural and anthropogenic factors can be reconstructed. The results of the diatom analysis of a 96 cm long continuous sediment core from the artic lake in the Pechora River delta (Nenets Autonomous Okrug, Russia) were presented. The arctic lake under study is characterized by low conductivity and nutrients content. In 33 samples taken from the la...

The Yamal Peninsula is one of the most important strategic oil and gas-bearing regions of Russia. Active development of the Far North territories threatens to have negative consequences for the delicate balance of Northern ecosystems, therefore their monitoring and comprehensive research are particularly relevant. In 2012-2013 during the expeditions on the Yamal, Yavay and Gyda peninsulas bottom sediments of the Unnamed lake (57.5 cm; 1300 cal yr BP), located in the catchment area of the Pyasedayakha river, were s...

The pollen record from a 96 cm long sediment core obtained in Lake Arcto-Pimberto (68°26.114' N, 053°32.311' E, Pechora river delta, Nenets Autonomous Okrug) reflect regional vegetation and climate changes in the north of the Eastern European plain over the last 6000 year. The taxonomic and stratigraphic structure of the column of bottom sediments is reflected in a spore-pollen diagram which was divided on the 4 biostratigraphic sequences - pollen zones (PZ I-IV). The results show that the bottom of the core (PZ I...

Zooplankton organisms are widely used as indicators of ecosystem changes (Adrian et al., 2009, Nigamatzyanova G., Frolova L., 2017). Both zooplankton and nutrients play an important role in monitoring and assessing water quality by greatly contributing to biological productivity (Vinberg,1960). In the current study, we examined water quality of different types of water bodies of Ob and Erkuta river basins, based on the analysis of zooplankton communities and the concentration of nutrients. 72 species of zooplankto...

The article describes a long-term and seasonal dynamics of zooplankton species diversity and its relationships with hydrologic factors were investigated on Lake Fish located in Samoylov Island on the northeast of the Republic of Sakha (Yakutia), Russia. This lake was chosen as a research object due to its mixed type of origin: thermokarst-polygonal. Zooplankton was sampled at three locations: on the pelagic and littoral zones of the thermokarst part and polygonal part of the lake. In total, 90 taxa (80 species) of...

Phreatalona protzi (Hartwig, 1900) is a rare species of Cladocera (Crustacea) known from Western Europe. However, hardly any ecological information about this species is available and it has not been included in lists of species found in North-East European Russia. Here we present first findings of Ph. protzi in lake sediments of a small tundra lake from the Pechora River delta, Nenets State Nature Reser, Russian Arctic. The bottom sediment samples from 11 tundra lakes were used for analysis of subfossil Cladocera...

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. Polar region of the Russia not only play the leading role in world climatic system, but also quickly, with high sensitivity react to climatic changes. Investigation of lake from arctic region has an extreme importance for understanding of the modern environmental processes and their influence on northern ecosystems and biological diversity of these regions. Limnological chara...

Zooplankton plays a significant role in organic and mineral components accumulation and vertical organic matter fluxes in lake ecosystems of the Pechora delta. The composition and structure of zooplankton in four small remote tundra lakes of the Pechora delta (Russia) during the summer of 2017 were analyzed. All tundra lakes under study are characterized by low conductivity and nutrients content. A total of 82 zooplankton taxa were identified, of which the most frequently occurring ones were rotifers (Conochilus u...

Cladocera (Crustacea: Branchiopoda) constitute a major component of the planktonic and benthic fauna of the high-latitude lakes. They are tolerant to extreme environmental conditions and are one of very few groups of aquatic animal that are not only able to persist in cold thermokarst lakes but to build up viable populations. Subfossil Cladocera were sampled from surface sediments of 20 thermokarst lakes along a transect crossing the tree line in the Khatanga-river basin, south of Taymyr Peninsula, north-central S...

The aim of the study was the analysis of subfossil Cladocera community of the Kotovo lake (Kharbey lakes' system, Bolshezemelskaya tundra) and the qualitative rating of the changes in it and in the region of study. The relevance of the work is associated with the increasing interest to the study of the climate change on the example of the North intact territories, along with the insufficient knowledge of the biota of the area being studied. The predominance of some species, zoogeography and biotopic attachments of...

The aim of our investigation is to reconstruct the local and regional palaeoenvironmental conditions and to highlight the rapid evolution of the thermokarst lake during the Holocene climate optimum. The investigated lake was located in Central Yakutia, Siberia, Russia. The investigated core was collected in a small pingo within a large Central Yakutian thermokarst Khara Bulgunnyakh basin (alas). According to ephippium analysis the formation of the lake coincided with the Holocene climatic optimum. Using cluster an...

Lake Suturuokha (69'06 "N, 145'23" E) is a unique lake within the Indigirka River basin, which is located on the border of the forest-tundra and taiga in the north of the Republic of Sakha (Yakutia). Formed due to the influence of glaciers of several glaciations in the late Pleistocene, the lake has a large area (69 km2) and comparatively shallow depths (2 - 2.5 m). Because of its unusual genesis and low study, the lake is of great interest to scientists. In August 2015, in the framework of the research expedition...

This study is devoted to the investigation of zooplankton biodiversity and their adaptation to the short growing season of polygonal pond, located in the largest Arctic delta - the delta of the Lena River (Republic of Sakha (Yakutia), Russia). Samples were obtained within the Russian-German project "Expedition Lena" (August 2013, June-August 2014). Investigated polygonal pond with thickets of macrophytes shallow, well-oxygenated, weakly mineralized with low conductivity, slightly alkaline pH. The pond freezes in w...

This investigation is aimed to determine general development patterns of the natural and climatic situations and lakes of the boreal zone in the later and postglacial time in the southeastern periphery of the Fennoscandian crystalline shield since the time of the last deglaciation. The analysis of the subfossil Cladoceran community was carried out on the basis of the 23 samples of Lake GahkozeroпїЅ bottom sediments in the Republic of Karelia. In the subfossil Cladoceran community of the lake 42 taxa have been iden...