TY - JOUR A1 - Tian, Fang A1 - Cao, Xianyong A1 - Dallmeyer, Anne A1 - Lohmann, Gerrit A1 - Zhang, Xu A1 - Ni, Jian A1 - Andreev, Andrei A1 - Anderson, Patricia M. A1 - Lozhkin, Anatoly V. A1 - Bezrukova, Elena A1 - Rudaya, Natalia A1 - Xu, Qinghai A1 - Herzschuh, Ulrike T1 - Biome changes and their inferred climatic drivers in northern and eastern continental Asia at selected times since 40 cal ka BP JF - Vegetation History and Archaeobotany N2 - Recent global warming is pronounced in high-latitude regions (e.g. northern Asia), and will cause the vegetation to change. Future vegetation trends (e.g. the "arctic greening") will feed back into atmospheric circulation and the global climate system. Understanding the nature and causes of past vegetation changes is important for predicting the composition and distribution of future vegetation communities. Fossil pollen records from 468 sites in northern and eastern Asia were biomised at selected times between 40 cal ka bp and today. Biomes were also simulated using a climate-driven biome model and results from the two approaches compared in order to help understand the mechanisms behind the observed vegetation changes. The consistent biome results inferred by both approaches reveal that long-term and broad-scale vegetation patterns reflect global- to hemispheric-scale climate changes. Forest biomes increase around the beginning of the late deglaciation, become more widespread during the early and middle Holocene, and decrease in the late Holocene in fringe areas of the Asian Summer Monsoon. At the southern and southwestern margins of the taiga, forest increases in the early Holocene and shows notable species succession, which may have been caused by winter warming at ca. 7 cal ka bp. At the northeastern taiga margin (central Yakutia and northeastern Siberia), shrub expansion during the last deglaciation appears to prevent the permafrost from thawing and hinders the northward expansion of evergreen needle-leaved species until ca. 7 cal ka bp. The vegetation-climate disequilibrium during the early Holocene in the taiga-tundra transition zone suggests that projected climate warming will not cause a northward expansion of evergreen needle-leaved species. KW - Siberia KW - China KW - Northern Asia KW - Model-data comparison KW - Pollen KW - Permafrost KW - Vegetation-climate disequilibrium Y1 - 2018 U6 - https://doi.org/10.1007/s00334-017-0653-8 SN - 0939-6314 SN - 1617-6278 VL - 27 IS - 2 SP - 365 EP - 379 PB - Springer CY - New York ER - TY - JOUR A1 - Huang, Xiaozhong A1 - Peng, Wei A1 - Rudaya, Natalia A1 - Grimm, Eric C. A1 - Chen, Xuemei A1 - Cao, Xianyong A1 - Zhang, Jun A1 - Pan, Xiaoduo A1 - Liu, Sisi A1 - Chen, Chunzhu A1 - Chen, Fahu T1 - Holocene vegetation and climate dynamics in the Altai Mountains and Surrounding Areas JF - Geophysical research letters N2 - A comprehensive understanding of the regional vegetation responses to long-term climate change will help to forecast Earth system dynamics. Based on a new well-dated pollen data set from Kanas Lake and a review on the published pollen records in and around the Altai Mountains, the regional vegetation dynamics and forcing mechanisms are discussed. In the Altai Mountains, the forest optimum occurred during 10-7ka for the upper forest zone and the tree line decline and/or ecological shifts were caused by climatic cooling from around 7ka. In the lower forest zone, the forest reached an optimum in the middle Holocene, and then increased openness of the forest, possibly caused by both climate cooling and human activities, took place in the late Holocene. In the lower basins or plains around the Altai Mountains, the development of protograssland or forest benefited from increasing humidity in the middle to late Holocene. Plain Language Summary In the Altai Mountains and surrounding area of central Asia, the previous studies of the Holocene paleovegetation and paleoclimate studies did not discuss the different ecological limiting factors for the vegetation in high mountains and low-elevation areas due to limited data. With accumulating fossil pollen data and surface pollen data, it is possible to understand better the geomorphological effect on the vegetation and discrepancies of vegetation/forest responses to large-scale climate forcing, and it is also possible to get reliable quantitative reconstructions of climate. Here our new pollen data and review on the published fossil pollen data will help us to look into the past climate change and vertical evolution of vegetation in this important area of the Northern Hemisphere. Based on our study, it can be concluded that the growth of taiga forest in the wetter areas may be promoted under a future warmer climate, while the forest in the relatively dry areas is liable to decline, and the different vegetation dynamics will contribute to future high-resolution coupled vegetation-climate model for Earth system modelling. KW - climate change KW - Kanas Lake KW - Altai Mountains KW - vegetation dynamics KW - taiga forest Y1 - 2018 U6 - https://doi.org/10.1029/2018GL078028 SN - 0094-8276 SN - 1944-8007 VL - 45 IS - 13 SP - 6628 EP - 6636 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Li, Huashu A1 - Liu, Xingqi A1 - Herzschuh, Ulrike A1 - Cao, Xianyong A1 - Yu, Zhitong A1 - Wang, Yong T1 - Vegetation and climate changes since the middle MIS 3 inferred from a Wulagai Lake pollen record, Inner Mongolia, Northeastern China JF - Review of palaeobotany and palynology : an international journal N2 - The climate conditions during Marine Isotope Stage (MIS) 3 were similar to present-day conditions, but whether humidity then exceeded present levels is debated, and the driving mechanisms of palaeoclimate evolution since MIS 3 remain unclear. Here, we use pollen data from Wulagai Lake, Inner Mongolia, to reconstruct vegetation and climate changes since the middle MIS 3. The steppe biome is reconstructed as the first dominant biome and the desert biome as the second, and the results show that the vegetation was steppe over the last 43,800 years. Poaceae, Artemisia, Caryophyllaceae and Humulus were abundant from middle to late MIS 3, indicating humid climate conditions. As drought-tolerant species such as Hippophae, Nitraria and Chenopodiaceae spread during MIS 2, the climate became arid. The Holocene is characterized by the dominance of steppe with mixed coniferous-broadleaved forests in the Greater Hinggan Range, and the desert biome retains high affinity scores, indicating that the climate was semi-arid. The climate from middle to late MIS 3 was wetter than in the Holocene; this shift was related to changes in the Northern Hemisphere's solar insolation and ice volume. The humid conditions during MIS 3 were attributed to strong ice–albedo feedback, which led to evaporation that was less than the precipitation. The enhanced evaporation caused by increased solar insolation and decreased ice volume might have exceeded the precipitation during the Holocene and resulted in low effective humidity in the Wulagai Lake basin. KW - Pollen KW - Biome KW - Ice volume KW - Solar insolation Y1 - 2018 U6 - https://doi.org/10.1016/j.revpalbo.2018.12.006 SN - 0034-6667 SN - 1879-0615 VL - 262 SP - 44 EP - 51 PB - Elsevier CY - Amsterdam ER -