Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

doi:10.1016/j.quascirev.2012.03.004

	Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia
	Mackay, Anson W.1; Bezrukova, Elena V.2; Leng, Melanie J.3; Meaney, Miriam 1; Nunes, Ana 1; Piotrowska, Natalia 4; Self, Angela 5; Shchetnikov, Alexander 6; Shilland, Ewan 1; Tarasov, Pavel 7
刊名	QUATERNARY SCIENCE REVIEWS
	2012-05-18
卷号	41 页码:119-131
关键词	Eastern Sayan mountains Lake ontogeny Pollen Biome Chironomid Diatom Organic isotope Multiproxy Redundancy analysis
ISSN号	0277-3791
DOI	10.1016/j.quascirev.2012.03.004
文献子类	Article
英文摘要	Boreal ecosystems are highly vulnerable to climate change, and severe ecological impacts in the near future are virtually certain to occur. We undertook a multiproxy study on an alpine lake (ESM-1) at the modern tree-line in boreal, southern Siberia. Steppe and tundra biomes were extensive in eastern Sayan landscapes during the early Holocene. Boreal forest quickly expanded by 9.1 ka BP, and dominated the landscape until c 0.7 ka BP, when the greatest period of compositional turnover occurred. At this time, alpine meadow landscape expanded and Picea obovata colonised new habitats along river valleys and lake shorelines, because of prevailing cool, moist conditions. During the early Holocene, chironomid assemblages were dominated by cold stenotherms. Diatoms for much of the Holocene were dominated by alkaliphilous, fragilarioid taxa, up until 0.2 ka BP, when epiphytic species expanded, indicative of increased habitat availability. C/N mass ratios ranged between 9.5 and 13.5 (11.1-15.8 C/N atomic ratios), indicative of algal communities dominating organic matter contributions to bottom sediments with small, persistent contributions from vascular plants. However, delta C-13 values increased steadily from -34.9 parts per thousand during the early Holocene (9.3 ka BP) to -24.8 parts per thousand, by 0.6 ka BP. This large shift in magnitude may be due to a number of factors, including increasing within-lake productivity, increasing disequilibrium between the isotopic balance of the lake with the atmosphere as the lake became isotopically 'mature', and declining soil respiration linked to small, but distinct retreat in forest biomes. The influence of climatic variables on landscape vegetation was assessed using redundancy analysis (RDA), a linear, direct ordination technique. Changes in July insolation at 60 degrees N significantly explained over one-fifth of the variation in species composition, while changes in estimates of northern hemisphere temperature and ice-rafted debris events in the North Atlantic were also significant, but considerably less important. The potential importance of climate and biome development (tundra, steppe, cold deciduous forest and taiga) on different trophic levels (i.e. chironomid and diatom communities) in lake ESM-1 was also assessed using RDA. Climate predictors had a more significant influence on Holocene chironomid assemblages, especially July insolation at 60 degrees N, estimates of regional precipitation and estimates of northern hemisphere temperature, while only the development of the taiga biome had a significant impact on these primary consumers. Diatom communities also had a small, but significant influence on Holocene chironomid populations, perhaps linked to variation in faunal feeding strategies. In contrast, climatic and biome predictors explained similar amounts of variation in the Holocene diatom assemblage (approximately 20% each), while chironomids themselves as predictors explained just under 7% of diatom variation. Lake acidity was inferred using a diatom inference model. Results suggest that after deglaciation, the lake did not undergo a process of gradual acidification, most likely due to the presence of continuous permafrost and low levels of precipitation, preventing base cations and dissolved organic carbon entering the lake (except for the period between 1.7 and 0.7 ka BP). We conclude that lakes in continental, boreal regions undergo different models of lake ontogeny than oceanic boreal regions.
WOS关键词	SEDIMENTARY ORGANIC-MATTER ; LAKE BAIKAL ; ENVIRONMENTAL-CHANGE ; ICE-COVER ; POSTGLACIAL HISTORY ; SOUTHERN SWEDEN ; ALTAI-MOUNTAINS ; WESTERN NORWAY ; POLLEN RECORDS ; ALPINE LAKE
WOS研究方向	Physical Geography ; Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000304568400010
资助机构	Baikal Archaeology Project ; Baikal Archaeology Project ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Baikal Archaeology Project ; Baikal Archaeology Project ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Baikal Archaeology Project ; Baikal Archaeology Project ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Baikal Archaeology Project ; Baikal Archaeology Project ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada ; Major Collaborative Research Initiative (MCRI) of the Social Sciences and Humanities Research Council of Canada
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/84670]
专题	中国科学院地质与地球物理研究所
通讯作者	Mackay, Anson W.
作者单位	1.UCL, Dept Geog, Environm Change Res Ctr, London WC1E 6BT, England 2.Russian Acad Sci, Inst Geochem, Siberian Branch, Irkutsk 664003, Russia 3.British Geol Survey, NERC, Isotope Geosci Lab, Keyworth NG12 5GG, Notts, England 4.Silesian Tech Univ, Inst Phys, Dept Radioisotopes, GADAM Ctr Excellence, PL-44100 Gliwice, Poland 5.Nat Hist Museum, London DW7 5BD, England 6.Russian Acad Sci, Inst Earths Crust, Siberian Branch, Irkutsk 664003, Russia 7.Free Univ Berlin, Inst Geol Sci, Palaeontol Sect, D-12249 Berlin, Germany 8.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Cenozo Geol & Environm, Beijing 100029, Peoples R China 9.Univ Southampton, Southampton SO17 1BF, Hants, England
推荐引用方式 GB/T 7714	Mackay, Anson W.,Bezrukova, Elena V.,Leng, Melanie J.,et al. Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia[J]. QUATERNARY SCIENCE REVIEWS,2012,41:119-131.
APA	Mackay, Anson W..,Bezrukova, Elena V..,Leng, Melanie J..,Meaney, Miriam.,Nunes, Ana.,...&White, Dustin.(2012).Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia.QUATERNARY SCIENCE REVIEWS,41,119-131.
MLA	Mackay, Anson W.,et al."Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia".QUATERNARY SCIENCE REVIEWS 41(2012):119-131.