Biogeographic patterns of planktonic and meiobenthic fauna diversity in inland waters of the Russian Arctic

Broad-scale assessment of biodiversity is needed for detection of future changes across substantial regions of the Arctic. Presently, there are large data and information gaps in species composition and richness of the freshwater planktonic and meiobenthos communities of the Russian Arctic. Analysis of these data is very important for identifying the spatial distribution and temporal changes in species richness and diversity of rotifers, cladocerans, and copepods in the continental Russian Arctic. We investigated biogeographic patterns of freshwater plankton and meiobenthos fromc. 67 degrees to 73 degrees N by analysing data over the period 1960-2017. These data include information on the composition of rotifers, cladocerans, and copepods obtained from planktonic and meiobenthic samples, as well as from subfossil remains in bottom sediments of seven regions from the Kola Peninsula in the west, to the Indigirka River Basin (east Siberia) in the east. Total richness included 175 species comprised of 49 rotifer genera, 81 species from 40 cladoceran genera, and 101 species from 42 genera of calanoid, cyclopoid, and harpacticoid copepods. Longitudinal trends in rotifer and micro-crustacean diversity were revealed by change in species composition from Europe to eastern Siberia. The most common and widespread species were 19 ubiquitous taxa that includedKellicottia longispina(Rotifera),Chydorus sphaericuss. lat. (Cladocera),Heterocope borealis,Acanthocyclops vernalis, andMoraria duthiei(Copepoda). The highest number of rare species was recorded in the well-studied region of the Bolshezemelskaya tundra and in the Putorana Plateau. The total number of copepod and rotifer species in both Arctic lakes and ponds tended to increase with latitude. Relative species richness of copepods was positively associated with waterbody area, elevation, and precipitation, while relative species richness of cladocerans was positively related to temperature. This result is consistent with known thermophilic characteristics of cladocerans and the cold tolerance properties of copepods, with the former being dominant in shallow, warmer waterbodies of some western regions, and the latter being dominant in large cold lakes and waterbodies of eastern regions. Rotifers showed a negative association with these factors. Alpha- and beta-diversity of zooplankton in the Russian Arctic were strongly related to waterbody type. Lake zooplankton communities were more diverse than those in pond and pool systems. Moreover, the highest beta-diversity values were observed in regions that showed a greater breadth in latitude and highly heterogeneous environmental conditions and waterbody types (Bolshezemelskaya tundra and Putorana Plateau). Redistribution of freshwater micro-fauna caused by human activities occurred in the 1990s and 2000s. As a result of climate warming, a few cladoceran species appear to have extended their range northward. Nevertheless, the rotifer and micro-crustacean fauna composition and diversity of the majority of Arctic regions generally remain temporally conservative, and spatial differences in composition and species richness are chiefly associated with the differences between the warmer European and colder east Siberian climates.Peer reviewe

Spatial-temporal coherence of different scale hydrological processes in the Lena River delta

The Lena River delta is one of the hydrologically entertaining objects. Hundreds channels and thousands lakes as well as thawing ice complex and permafrost active layer dynamic allow to investigate spatial-temporal coherence of different scale hydrological processes. During 15 years Russian-German scientific collaboration on hydrological, hydrochemical and hydrobiological studies have been operated on different water objects for cause-effect relation of large and specific micro processes indication. Transient liquid-frozen water phase change is significant not only for active layer runoff forming but also for hydrochemical and biological specific. Thus, maximum of DOC is in the overlaying soil layer than permafrost border [Bobrova et al., 2013]. It could be used for modeling of runoff forming and biological activity estimation. Measured temperature of lacustrine bottom sediment of one thermokarst lake on Samoylov Island shows maximal volume 3,7 °C on 1,75 cm beneath water-sediment border [Skorospekhova, 2015]. It is also can be interpreted as biological processes activity, for example, organic material destruction with additional heating. It could be observed more detail and can be used for modeling of a lake thermic regime. Hydrobiological specificity shows similarity of species in the channels and lakes, poorness of biodiversity, especially in big channel; only stagnant in summer season Bulkurskaya channel has more zooplankton species in four times than the main river channel [Nigamatzyanova et al., 2015]. Decline of water turbidity from the delta top to channel edges is about 5-8 times [Charkin et al., 2009]. Considerable turbidity increase is formed according to permafrost thawing and can reach 500 g l-1 including high concentration of carbon and biogenic elements. Thermokarst lake degradation [Morgenstern et al., 2011] plays also an important role for permafrost hydrology in the delta. Outflow from an ice complex forms a high local suspended supply in adjacent river branches and influences on biological processes consequently [Dubinenkov et al., 2015]. Underestimated effect of water and sediment discharge increase in the middle part of river branches had been marked [Fedorova et al., 2015]. Head flux of the large Lena River forms taliks under channels with more sophisticated affect in the shoreline zone of the Laptev Sea due to aquifer dynamic and mixing of fresh and salt water. Talik effect on hydrology and sedimentation (and suspended material transformation) in the central part of the delta is currently carried out according to geophysical and hydrogeological methods. First field measurements are planned to be done in April 2016 and results will be presented in the ICOP 2016. The studies have been done with support of RFBR grant 14-05-00787 and 15-35-50949, in the framework of Russian-German projects “ CarboPerm” and “Scientific station “Samoylov Island”. The project for both SPBU and DFG funding had also applied for field and scientific investigation as well. References Bobrova, O.; Fedorova, I.; Chetverova, A.; Runkle, B. and Potapova, T. Input of Dissolved Organic Carbon for Typical Lakes in Tundra Based on Field Data of the Expedition Lena–2012. In Proceedings of the 19th International Northern Research Basins Symposium and Workshop, Southcentral Alaska, USA – August 11–17, 2013, 2013. Charkin, A.N.; Dudarev, O.V.; Semiletov, I.P.; Fedorova, I.; Chetverova, A.A.; J., Vonk; Sanchez- Garcia, L.; Gustafsson, ö. and Andersson, P. edimentation in the System of the Delta Lena River - the South Western Part of Buor-Haya Gulf (the Laptev Sea). In The 16th International Symposium on Polar Sciences. Incheon, Korea. 2009, 2009. Dubinenkov, I.; Flerus, R.; Schmitt-Kopplin, P.; Kattner, G. and Koch, B.P. [2015]: Origin-specific molecular signatures of dissolved organic matter in the Lena Delta. Biogeochemistry, 123(1):1–14, doi:10.1007/s10533-014-0049-0. Fedorova, I.; Chetverova, A.; Bolshiyanov, D.; Makarov, A.; Boike, J.; Heim, B.; Morgenstern, A.; Overduin, P. P.; Wegner, C.; Kashina, V.; Eulenburg, A.; Dobrotina, E. and Sidorina, I. [2015]: Lena delta hydrology and geochemistry: long-term hydrological data and recent field observations. Biogeosciences, 12(2):345–363, doi:10.5194/bg-12-345-2015. Morgenstern, A.; Grosse, G.; Günther, F.; Fedorova, I. and Schirrmeister, L. [2011]: Spatial analyses of thermokarst lakes and basins in Yedoma landscapes of the Lena Delta. The Cryosphere, 5(4):849–867, doi:10.5194/tc-5-849-2011. Nigamatzyanova, G.; Frolova, L.; Chetverova, A. and Fedorova, I. Hydrobiological investigation of branches of the Lena River edge zone. In Uchenye Zapiski Kazanskogo Universiteta, Seriya Estestvennye Nauki. 2015. in Russian. Skorospekhova, T. Report of a spring campaign of the expedition “Lena 2015”. AARI’s library stock, 2015

Pollen and spore record of lake sediments, the southern part of the Yamal peninsula, Russia

Palynological data have been obtained from the lake sediments, the southern part of the Yamal peninsula. For the spore-pollen analysis we used a 30 cm core of bottom sediments from one of the water bodies of the Yerkuta river basin with the code name K1 (68°15.320' N, 69°07.675' E), collected during the expedition in 2014. The study object is a small lake with a surface area of 0.43 km2 and maximum depth of 6.5 m. The water temperature of the lake averaged 9.2°C. Based on the hydrogen index value (pH= 6.93), the lake water was characterized as close to neutral. Based on the palynological analysis of the lake sediments 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, Alnaster, Salix, Ericaceae. Herbaceous taxa are composed mainly by Cyperaceae, Poaceae with a small admixture of forbs. Mosses are represented by Sphagnum, Lycopodiaceae. It has been found that the lower part of the core from 29 cm to 18 cm formed in a cold and humid climate. The middle part of the column from 18 to 8 cm laid under more favorable conditions - an increase in the total concentration of pollen in the sediments was noticeable. The top of the column from 8 to 0 cm points to cold and humid climate. The vegetation, which produced the pollen at this period, was same to the modern type

Data on taxa composition of freshwater zooplankton and meiobenthos across Arctic regions of Russia

We present the presence/absence species list (Table 1) of rotifer, cladoceran, and copepod (Calanoida, Harpacticoida, and Cyclopoida) fauna from seven Arctic regions of Russia (the Kola Peninsula, the Pechora River Delta, the Bolshezemelskaya tundra, the Polar Ural, the Putorana Plateau, the Lena River Delta, and the Indigirka River Basin) based on our own and literature data. Our own records were obtained by analyzing samples of zooplankton, meiobenthos, and two cores of bottom sediments (from the Kola Peninsula and the Bolshezemelskaya tundra lakes) that we collected once in July or August in 1992, 1995–2017. To supplement the list, we used relevant literature with periods of research from the 1960s to the 2010s. The list is almost identical to “Dataset 2: Zooplankton and Meiofauna across Arctic Regions of Russia”, which was analyzed but not published in [1]. The detailed analysis of this list revealed the specific composition of the aquatic fauna associated with the climatic and geographical factors [1]. The data provide information on the current state of biodiversity and species richness in Arctic fresh waters and can serve as the basis for monitoring these environments and predicting how they are likely to change in the future

Cladoceran analysis of sediment core 17-Ya-01 from a anonymous lake in the Yamalo-Nenets Autonomous Okrug, Arctic Russia

Cladocerans are very promising for studying climate change risks owing to their inherently predictive nature. For paleoecological study, one sediment core (17-Ya-01) was sampled from lake in Yamalo-Nenets Autonomous Okrug (Russia). Cladoceran analysis of the sediment core with a length of 51 cm collected from the studied lake is performed. A total of 30 taxa were registered in the subfossil cladoceran community of the lake. Most of the identified taxa belong to the Chydoridae family. Bosmina (Eubosmina) longispina was the dominant species. Of special interest is the finding of Ophryoxus gracilis and Rhynchotalona latens - rare species

Diatoms from the bottom sediments of Lake Shira (Khakassia, Russia)

Diatoms are good indicators of a variety of lake water conditions including salinity, pH, light availability, temperature and nutrient levels, but diatoms as palaeoindicators are poorly studied in the Lake Shira. Our research on the species composition and ecological parameters of diatoms provide additional data for the regional databases and contributes to improving the accuracy of paleoecological reconstructions. In this study the diatom results of analysis a 528 cm long continuous sediments core from the Lake Shira (Khakassia, Russia) are presented. The core was collected in August 2020 from central part of the lake from a depth of 24 m. 39 samples were investigated by us for diatom analysis. Diatoms were found only in 13 samples. Diatom analysis of samples revealed 30 taxa, belonging to 19 genera. The analysis of the ecological structure of the diatom flora of the sediment core sample from the lake under study shows that it is dominated by the cosmopolitan representatives of benthic and planktonic-benthic, indifferent to salinity and halophiles organisms giving preference to the alkaline environmental conditions. The prevalence of Handmannia comta (Ehrenberg) Kociolek & Khursevich diatom in sediments have been established

Palynologycal record of a long sediment core from Lake Shira (Minusinsk Depression, South Siberia, Russia)

In 2022, a 530 cm long sediment core (Shira core 3, 54°31̍18,2̎ N, 90°10̍43,7̎ E) was recovered from 24 m depth in the central part of Lake Shira. Lake Shira is located in Minusinsk Depression of the mountains of Southern Siberia (Khakassia, Russia). It is a meromictic lake with an area of 35.9 km2 and an average depth about 11 m (the maximum depth of 24 m). The lake's salinity varies considerably and can reach up to 27 g/l. The surrounding vegetation consist of steppe associations (Artemisia and Poaceae species predominate), birches and small forest patches

Freshwater communities and environmental data of a polygonal tundra landscape at the Berelekh River in the Indigirka lowland (NE Siberia)

Patterned ground of the polygonal tundra yields sensitive indicators of environmental and climate change. Polygon ponds, mires and cryosoils are typical components of Arctic Siberian wetlands underlain by permafrost.Field studies of recent environmental dynamics were carried out in the Indigirka lowland in summer 2011 and 2012. Using a multidisciplinary approach, several stages of polygonal systems were studied as modern tundra habitats in the surrounding of the WWF station Kytalyk at the Berelekh River, a tributary of the Indigirka River. The floral and faunal associations of the polygonal tundra landscape were described. Ecological, hydrological, meteorological, limnological and cryological features were analyzed in order to evaluate modern environmental conditions and their essential controlling parameters. A monitoring program was carried out to measure changes of air, water and ground temperatures as well as water conductivity, water level and soil moisture and to collect water, diatom, zooplankton, zoobenthos, tecamoebae, phytoplankton and ostracod samples. These data sets contain environmental field data, logger data, various ecological data, and analyses of sediments and water

Ground temperature data of a tundra polygonal lake near the WWF station Kytalyk at the Berelekh River in the Indigirka lowland (NE Siberia) from 2011-2012

Patterned ground of the polygonal tundra yields sensitive indicators of environmental and climate change. Polygon ponds, mires and cryosoils are typical components of Arctic Siberian wetlands underlain by permafrost. Field studies of recent environmental dynamics were carried out in the Indigirka lowland in summer 2011 and 2012. Using a multidisciplinary approach, several stages of polygonal systems were studied as modern tundra habitats in the surrounding of the WWF station Kytalyk at the Berelekh River, a tributary of the Indigirka River. The floral and faunal associations of the polygonal tundra landscape were described. Ecological, hydrological, meteorological, limnological and cryological features were analyzed in order to evaluate modern environmental conditions and their essential controlling parameters. A monitoring program was carried out to measure changes of air, water and ground temperatures as well as water conductivity, water level and soil moisture and to collect water, diatom, zooplankton, zoobenthos, tecamoebae, phytoplankton and ostracod samples. These data sets contain environmental field data, logger data, various ecological data, and analyses of sediments and water. This dataset comprises ground temperature measurements at different depth at the center and wall of a polygonal lake from 2011-2012

Hydrochemistry data of a polygonal lakes near the WWF station Kytalyk at the Berelekh River in the Indigirka lowland (NE Siberia) during summer 2011

Patterned ground of the polygonal tundra yields sensitive indicators of environmental and climate change. Polygon ponds, mires and cryosoils are typical components of Arctic Siberian wetlands underlain by permafrost. Field studies of recent environmental dynamics were carried out in the Indigirka lowland in summer 2011 and 2012. Using a multidisciplinary approach, several stages of polygonal systems were studied as modern tundra habitats in the surrounding of the WWF station Kytalyk at the Berelekh River, a tributary of the Indigirka River. The floral and faunal associations of the polygonal tundra landscape were described. Ecological, hydrological, meteorological, limnological and cryological features were analyzed in order to evaluate modern environmental conditions and their essential controlling parameters. A monitoring program was carried out to measure changes of air, water and ground temperatures as well as water conductivity, water level and soil moisture and to collect water, diatom, zooplankton, zoobenthos, tecamoebae, phytoplankton and ostracod samples. These data sets contain environmental field data, logger data, various ecological data, and analyses of sediments and water. This dataset comprises hydrochemical measurements of polygonal lakes, near the WWF station Kytalyk at the Berelekh River