TY - JOUR A1 - Syrykh, Lydmila S. A1 - Nazarova, Larisa B. A1 - Herzschuh, Ulrike A1 - Subetto, D. A. A1 - Grekov, I. M. T1 - Reconstruction of palaeoecological and palaeoclimatic conditions of the Holocene in the south of the Taimyr according to an analysis of lake sediments JF - Contemporary Problems of Ecology N2 - A sediment core from Khatanga-12 Lake (Taimyr Peninsula, Krasnoyarsk krai) has been studied. The 131.5-cm-long core covers ca. 7100 years of sedimentation. Chironomid analysis, a qualitative reconstruction of the paleoenvironment in the region, and a quantitative reconstruction of variations of the mean July air temperature and in the water depth of the lake have been performed using Northern Russia chironomid-inferred mean July temperature models (Nazarova et al., 2008, 2011, 2015). Khatanga-12 Lake was formed during the Middle Holocene warming as a result of thermokarst processes. The development of the lake ecosystem at different stages of its development was influenced by climatic and cryolithogenic factors. The Middle Holocene warming, which occurred around 7100-6250 cal. years BP, activated thermokarst processes and resulted in the formation of the lake basin. Later, between 6250 and 4500 cal. years BP, a period of cooling took place, as is proved by chironomid analysis. The bottom sediments of the lake during this period were formed by erosion processes on the lake shores. The reconstructed conditions were close to the modern after 2500 cal. years BP. KW - Chironomidae KW - paleolimnology KW - Holocene KW - climate reconstructions KW - Russian Arctic region KW - Khatanga Y1 - 2017 U6 - https://doi.org/10.1134/S1995425517040114 SN - 1995-4255 SN - 1995-4263 VL - 10 SP - 363 EP - 369 PB - Pleiades Publ. CY - New York ER - TY - JOUR A1 - Subetto, D. A. A1 - Nazarova, Larisa B. A1 - Pestryakova, Luidmila Agafyevna A1 - Syrykh, Liudmila A1 - Andronikov, A. V. A1 - Biskaborn, Boris A1 - Diekmann, Bernhard A1 - Kuznetsov, D. D. A1 - Sapelko, T. V. A1 - Grekov, I. M. T1 - Paleolimnological studies in Russian northern Eurasia BT - a review JF - Contemporary Problems of Ecology N2 - This article presents a review of the current data on the level of paleolimnological knowledge about lakes in the Russian part of the northern Eurasia. The results of investigation of the northwestern European part of Russia as the best paleolimnologically studied sector of the Russian north is presented in detail. The conditions of lacustrine sedimentation at the boundary between the Late Pleistocene and Holocene and the role of different external factors in formation of their chemical composition, including active volcanic activity and possible large meteorite impacts, are also discussed. The results of major paleoclimatic and paleoecological reconstructions in northern Siberia are presented. Particular attention is given to the databases of abiotic and biotic parameters of lake ecosystems as an important basis for quantitative reconstructions of climatic and ecological changes in the Late Pleistocene and Holocene. Keywords: paleolimnology, lakes, bottom sediments, northern. KW - paleolimnology KW - lakes KW - bottom sediments KW - northern Eurasia KW - Russian Arctic KW - databases Y1 - 2017 U6 - https://doi.org/10.1134/S1995425517040102 SN - 1995-4255 SN - 1995-4263 VL - 10 SP - 327 EP - 335 PB - Pleiades Publ. CY - New York ER - TY - JOUR A1 - Frolova, Larissa A. A1 - Ibragimova, A. G. A1 - Subetto, D. A. A1 - Nazarova, Larisa B. A1 - Syrykh, Lydmila S. T1 - Paleoecological and paleoclimatic reconstructions for the Karelian Isthmus based on the study of subfossil cladocerans from Lake Medvedevskoe (Northwest Russia) JF - Učënye Zapiski Kazanskogo Universiteta. Seriâ Estestvennye Nauki JF - Proceedings of Kazan University. Natural Sciences Series N2 - The purpose of our study is to reconstruct the climatic and environmental changes that took place over the Holocene in Northwest Russia. The results of the palaeobiological analysis of cladoceran community of Lake Medvedevskoe (Karelian Isthmus, located between the Gulf of Finland of the Baltic Sea and Lake Ladoga, Northwest Russia) have been discussed. In the sediments of Lake Medvedevskoe, we have identified 38 cladoceran taxa that belong to 7 families: Bosminidae, Holopedidae, Chydoridae, Daphnidae, Polyphemidae, Macrotricidae, and Sididae. It has been revealed that Bosmina (Eubosmina) longispina and Alonella nana are the most common for subfossil Cladocera community of the lake. Palearctic and Holarctic species are dominant. Both pelagic and littoral taxa are well represented in the lake. The down-core changes in cladoceran community allowed to identify five statistically significant zones. It has been discovered that the taxonomic richness of biological communities is low at the bottom of the core with the dominance of typical northern species and increases towards the sediment surface alongside with the rise of organic content in sediments. Based on the shifts in the taxonomic composition of cladoceran community, we have concluded upon the trophic status of the lake and climate changes. The obtained data have been compared with the results of the chironomid analysis that was performed earlier. KW - paleoclimatic reconstructions KW - subfossil Cladocera KW - Lake Medvedevskoe KW - Karelian Isthmus Y1 - 2017 SN - 2542-064X SN - 2500-218X VL - 160 IS - 1 SP - 93 EP - 110 PB - Kazan Federal University CY - Kazan ER - TY - JOUR A1 - Nazarova, Larisa B. A1 - Subetto, D. A. A1 - Syrykh, Lydmila S. A1 - Grekov, I. M. A1 - Leontev, P. A. T1 - Reconstructions of Paleoecological and Paleoclimatic Conditions of the Late Pleistocene and Holocene according to the Results of Chironomid Analysis of Sediments from Medvedevskoe Lake (Karelian Isthmus) JF - Doklady Earth Sciences N2 - The use of chironomids (Diptera: Chironomidae) as indicators of changes in natural and climatic settings allows one to reconstruct paleoclimatic and paleoenvironmental conditions. Based on the results of lithological and chironomid analyses, the loss on ignition (LOI) values, as well as the results of radiocarbon dating (C-14 AMS), new data on the paleoclimate in the Karelian Isthmus, in particular the quantitative reconstruction of the mean July temperature (T (July), A degrees C) in the Late Pleistocene and Holocene and the evolution of the ecosystem of Medvedevskoe Lake have been obtained. Y1 - 2018 U6 - https://doi.org/10.1134/S1028334X18060144 SN - 1028-334X SN - 1531-8354 VL - 480 IS - 2 SP - 710 EP - 714 PB - Pleiades Publ. CY - New York ER - TY - JOUR A1 - Engels, Stefan A1 - Medeiros, Andrew S. A1 - Axford, Yarrow A1 - Brooks, Steve A1 - Heiri, Oliver A1 - Luoto, Tomi P. A1 - Nazarova, Larisa B. A1 - Porinchu, David F. A1 - Quinlan, Roberto A1 - Self, Angela E. T1 - Temperature change as a driver of spatial patterns and long-term trends in chironomid (Insecta: Diptera) diversity JF - Global change biology N2 - Anthropogenic activities have led to a global decline in biodiversity, and monitoring studies indicate that both insect communities and wetland ecosystems are particularly affected. However, there is a need for long-term data (over centennial or millennial timescales) to better understand natural community dynamics and the processes that govern the observed trends. Chironomids (Insecta: Diptera: Chironomidae) are often the most abundant insects in lake ecosystems, sensitive to environmental change, and, because their larval exoskeleton head capsules preserve well in lake sediments, they provide a unique record of insect community dynamics through time. Here, we provide the results of a metadata analysis of chironomid diversity across a range of spatial and temporal scales. First, we analyse spatial trends in chironomid diversity using Northern Hemispheric data sets overall consisting of 837 lakes. Our results indicate that in most of our data sets, summer temperature (T-jul) is strongly associated with spatial trends in modern-day chironomid diversity. We observe a strong increase in chironomid alpha diversity with increasing T-jul in regions with present-day T-jul between 2.5 and 14 degrees C. In some areas with T-jul > 14 degrees C, chironomid diversity stabilizes or declines. Second, we demonstrate that the direction and amplitude of change in alpha diversity in a compilation of subfossil chironomid records spanning the last glacial-interglacial transition (similar to 15,000-11,000 years ago) are similar to those observed in our modern data. A compilation of Holocene records shows that during phases when the amplitude of temperature change was small, site-specific factors had a greater influence on the chironomid fauna obscuring the chironomid diversity-temperature relationship. Our results imply expected overall chironomid diversity increases in colder regions such as the Arctic under sustained global warming, but with complex and not necessarily predictable responses for individual sites. KW - Arctic KW - biodiversity KW - climate warming KW - freshwater ecosystems KW - insects KW - palaeoecology KW - Quaternary Y1 - 2019 U6 - https://doi.org/10.1111/gcb.14862 SN - 1354-1013 SN - 1365-2486 VL - 26 IS - 3 SP - 1155 EP - 1169 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Plikk, Anna A1 - Engels, Stefan A1 - Luoto, Tomi P. A1 - Nazarova, Larisa B. A1 - Salonen, J. Sakari A1 - Helmens, Karin F. T1 - Chironomid-based temperature reconstruction for the Eemian Interglacial (MIS 5e) at Sokli, northeast Finland JF - Journal of paleolimnology N2 - The Last Interglacial (Eemian, MIS 5e) can be considered a test-bed for climate dynamics under a warmer-than-present climate. In this study we present a chironomid record from the high latitude Sokli site (N Finland), where a long continuous sediment sequence from the last interglacial has been preserved from glacial erosion. The chironomid-analysis shows a diverse fauna, with dominance of warm-water indicators and shifts in assemblage composition that can be attributed to temperature, lake depth, productivity and habitat availability. Quantitative mean July paleotemperature estimates based on the chironomid data indicate overall mean July air temperatures up to 1 degrees C warmer than present. Two cooling events can be discerned, the Tunturi event, dated to about 127.5kaBP, in the lower part of the sequence, and the Varrio event, dated to about 119kaBP, associated with the beginning of a cooling trend in the upper part of the record. Warm conditions already at the onset of the interglacial contrast with a recent chironomid-based last interglacial temperature reconstruction from Denmark, which suggests a late onset of Eemian warming. The relatively small increase in inferred temperatures compared to present day temperatures at Sokli differs from other high latitude Eemian sites, and likely reflects the influence of the Atlantic Meridional Overturning Circulation in maintaining already elevated temperatures in Fennoscandia during interglacials. KW - Paleoclimate KW - Abrupt events KW - Last Interglacial KW - AMOC KW - Transfer functions KW - Validation Y1 - 2019 U6 - https://doi.org/10.1007/s10933-018-00064-y SN - 0921-2728 SN - 1573-0417 VL - 61 IS - 3 SP - 355 EP - 371 PB - Springer Science CY - Dordrecht ER - TY - JOUR A1 - Nazarova, Larisa B. A1 - Razjigaeva, N. G. A1 - Diekmann, Bernhard A1 - Grebennikova, T. A. A1 - Ganzey, L. A. A1 - Belyanina, N. I. A1 - Arslanov, K. A. A1 - Kaistrenko, V. M. A1 - Gorbunov, A. O. A1 - Kharlamov, A. A. A1 - Golovatyuk, L. V. A1 - Syrykh, Lydmila S. A1 - Subetto, D. A. A1 - Lisitsyn, A. P. T1 - Reconstruction of Holocene Environmental Changes in North-Western Pacific in Relation to Paleorecord from Shikotan Island JF - Doklady earth sciences N2 - Results of a paleolimnological investigation of a well-dated lake sediment section from Shikotan Island (Southern Kurils) showed that from ca 8.0 to 5.8 cal ka BP a warm and humid period corresponding to middle Holocene optimum took place. Cooling thereafter corresponds to Neoglacial. A reconstructed from ca 0.9 to ca 0.58 cal ka BP warm period can correspond to a Medieval Warm Period. Cooling after 0.58cal ka BP can be correlated with the LIA. Marine regression stages were identified at ca 6.2-5.9, 5.5-5.1 and 1.07-0.36 cal ka BP. The general chronology of major climatic events of Holocene in the island is in accordance with the climate records from the North Pacific region. Revealed spatial differences in timing and magnitude of the Late Holocene climatic episodes (LIA, MWP) in the region needs further investigations. Y1 - 2019 U6 - https://doi.org/10.1134/S1028334X19050143 SN - 1028-334X SN - 1531-8354 VL - 486 IS - 1 SP - 494 EP - 497 PB - Pleiades Publ. CY - New York ER - TY - JOUR A1 - Biskaborn, Boris A1 - Nazarova, Larisa B. A1 - Pestryakova, Luidmila Agafyevna A1 - Syrykh, Liudmila A1 - Funck, Kim A1 - Meyer, Hanno A1 - Chapligin, Bernhard A1 - Vyse, Stuart Andrew A1 - Gorodnichev, Ruslan A1 - Zakharov, Evgenii A1 - Wang, Rong A1 - Schwamborn, Georg A1 - Bailey, Hannah L. A1 - Diekmann, Bernhard T1 - Spatial distribution of environmental indicators in surface sediments of Lake Bolshoe Toko, Yakutia, Russia JF - Biogeosciences N2 - Rapidly changing climate in the Northern Hemisphere and associated socio-economic impacts require reliable understanding of lake systems as important freshwater resources and sensitive sentinels of environmental change. To better understand time-series data in lake sediment cores, it is necessary to gain information on within-lake spatial variabilities of environmental indicator data. Therefore, we retrieved a set of 38 samples from the sediment surface along spatial habitat gradients in the boreal, deep, and yet pristine Lake Bolshoe Toko in southern Yakutia, Russia. Our methods comprise laboratory analyses of the sediments for multiple proxy parameters, including diatom and chironomid taxonomy, oxygen isotopes from diatom silica, grain-size distributions, elemental compositions (XRF), organic carbon content, and mineralogy (XRD). We analysed the lake water for cations, anions, and isotopes. Our results show that the diatom assemblages are strongly influenced by water depth and dominated by planktonic species, i.e. Pliocaenicus bolshetokoensis. Species richness and diversity are higher in the northern part of the lake basin, associated with the availability of benthic, i.e. periphytic, niches in shallower waters. delta O-18(diatom) values are higher in the deeper south-western part of the lake, probably related to water temperature differences. The highest amount of the chironomid taxa underrepresented in the training set used for palaeoclimate inference was found close to the Utuk River and at southern littoral and profundal sites. Abiotic sediment components are not symmetrically distributed in the lake basin, but vary along restricted areas of differential environmental forcing. Grain size and organic matter are mainly controlled by both river input and water depth. Mineral (XRD) data distributions are influenced by the methamorphic lithology of the Stanovoy mountain range, while elements (XRF) are intermingled due to catchment and diagenetic differences. We conclude that the lake represents a valuable archive for multiproxy environmental reconstruction based on diatoms (including oxygen isotopes), chironomids, and sediment-geochemical parameters. Our analyses suggest multiple coring locations preferably at intermediate depth in the northern basin and the deep part in the central basin, to account for representative bioindicator distributions and higher temporal resolution, respectively. Y1 - 2019 U6 - https://doi.org/10.5194/bg-16-4023-2019 SN - 1726-4170 SN - 1726-4189 VL - 16 IS - 20 SP - 4023 EP - 4049 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Zhilich, Snezhana A1 - Rudaya, Natalia A1 - Krivonogov, Sergei A1 - Nazarova, Larisa B. A1 - Pozdnyakov, Dmitry T1 - Environmental dynamics of the Baraba forest-steppe (Siberia) over the last 8000 years and their impact on the types of economic life of the population JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - This article offers a reconstruction of the vegetation and climate of the south-western Siberian Baraba forest-steppe area during the last ca. 8000 years. The analysis of palynological data from the sediment core of Lake Bolshie Toroki using quantitative methods has made it possible to reconstruct changes of the dominant types of vegetation and mean July air temperatures. Coniferous forests grew in the vicinity of the lake, and mean July air temperatures were similar to present-day ones between 7.9 and 7.0 kyr BP. The warmest and driest climate occurred at 7.0-5.0 kyr BP. At that time, the region had open steppe landscapes; birch groves began to spread. A cooling trend is seen after 5.5 kyr BP, when forest-steppe began to emerge. Steppe communities started to dominate again after 1.5 kyr BP. Mean July air temperatures lower than now are reconstructed for the period of 1.9-1 kyr BP, and then the temperatures became similar to present-day ones. Comparing the archaeological data on the types of economy of the population which inhabited the Baraba forest-steppe with the data on changes in the natural environment revealed a connection between the gradual transition from hunting and fishing to livestock breeding and the development of forest-steppe landscapes with a decrease in the area covered by forests. The development of the forest-steppe as an ecotonic landscape starting around 5 kyr BP might have contributed to the coexistence of several archaeological cultures with different types of economy on the same territory. (C) 2017 Elsevier Ltd. All rights reserved. KW - Holocene KW - Climate dynamics KW - Russia KW - Vegetation dynamics KW - Baraba forest-steppe KW - Archaeology KW - Transfer function Y1 - 2017 U6 - https://doi.org/10.1016/j.quascirev.2017.03.022 SN - 0277-3791 VL - 163 SP - 152 EP - 161 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Palagushkina, Olga A1 - Wetterich, Sebastian A1 - Biskaborn, Boris A1 - Nazarova, Larisa B. A1 - Schirrmeister, Lutz A1 - Lenz, Josefine A1 - Schwamborn, Georg A1 - Grosse, Guido T1 - Diatom records and tephra mineralogy in pingo deposits of Seward Peninsula, Alaska JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - Vast areas of the terrestrial Subarctic and Arctic are underlain by permafrost. Landscape evolution is therefore largely controlled by climate-driven periglacial processes. The response of the frozen ground to late Quaternary warm and cold stages is preserved in permafrost sequences, and deducible by multi-proxy palaeoenvironmental approaches. Here, we analyse radiocarbon-dated mid-Wisconsin Interstadial and Holocene lacustrine deposits preserved in the Kit-1 pingo permafrost sequence combined with water and surface sediment samples from nine modern water bodies on Seward Peninsula (NW Alaska) to reconstruct thermokarst dynamics and determine major abiotic factors that controlled the aquatic ecosystem variability. Our methods comprise taxonomical diatom analyses as well as Detrended Correspondence Analysis (DCA) and Redundancy Analysis (RDA). Our results show, that the fossil diatom record reflects thermokarst lake succession since about 42 C-14 kyr BP. Different thermolcarst lake stages during the mid-Wisconsin Interstadial, the late Wisconsin and the early Holocene are mirrored by changes in diatom abundance, diversity, and ecology. We interpret the taxonomical changes in the fossil diatom assemblages in combination with both modern diatom data from surrounding ponds and existing micropalaeontological, sedimentological and mineralogical data from the pingo sequence. A diatom based quantitative reconstruction of lake water pH indicates changing lake environments during mid-Wisconsin to early Holocene stages. Mineralogical analyses indicate presence of tephra fallout and its impact on fossil diatom communities. Our comparison of modern and fossil diatom communities shows the highest floristic similarity of modern polygon ponds to the corresponding initial (shallow water) development stages of thermolcarst lakes. We conclude, that mid-Wisconsin thermokarst processes in the study area could establish during relatively warm interstadial climate conditions accompanied by increased precipitation due to approaching coasts, while still high continentality and hence high seasonal temperature gradients led to warm summers in the central part of Beringia. (C) 2017 Elsevier B.V. All rights reserved. KW - Microalgae assemblages KW - Palaeoenvironments KW - Thermokarst KW - Late Quaternary KW - Permafrost Y1 - 2017 U6 - https://doi.org/10.1016/j.palaeo.2017.04.006 SN - 0031-0182 SN - 1872-616X VL - 479 SP - 1 EP - 15 PB - Elsevier CY - Amsterdam ER -