TY - GEN A1 - Dallmeyer, Anne A1 - Claussen, Martin A1 - Ni, Jian A1 - Cao, Xianyong A1 - Wang, Yongbo A1 - Fischer, Nils A1 - Pfeiffer, Madlene A1 - Jin, Liya A1 - Khon, Vyacheslav A1 - Wagner, Sebastian A1 - Haberkorn, Kerstin A1 - Herzschuh, Ulrike T1 - Biome changes in Asia since the mid-Holocene BT - An analysis of different transient Earth system model simulations T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - The large variety of atmospheric circulation systems affecting the eastern Asian climate is reflected by the complex Asian vegetation distribution. Particularly in the transition zones of these circulation systems, vegetation is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate-vegetation relationship is lacking. To assess the Holocene vegetation change and to obtain an ensemble of potential mid-Holocene biome distributions for eastern Asia, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient Holocene climate simulations performed in coupled atmosphere-ocean(-vegetation) models. The simulated biome changes are compared with pollen-based biome records for different key regions. In all simulations, substantial biome shifts during the last 6000 years are confined to the high northern latitudes and the monsoon-westerly wind transition zone, but the temporal evolution and amplitude of change strongly depend on the climate forcing. Large parts of the southern tundra are replaced by taiga during the mid-Holocene due to a warmer growing season and the boreal treeline in northern Asia is shifted northward by approx. 4 degrees in the ensemble mean, ranging from 1.5 to 6 degrees in the individual simulations, respectively. This simulated treeline shift is in agreement with pollen-based reconstructions from northern Siberia. The desert fraction in the transition zone is reduced by 21% during the mid-Holocene compared to pre-industrial due to enhanced precipitation. The desert-steppe margin is shifted westward by 5 degrees (1-9 degrees in the individual simulations). The forest biomes are expanded north-westward by 2 degrees, ranging from 0 to 4 degrees in the single simulations. These results corroborate pollen-based reconstructions indicating an extended forest area in north-central China during the mid-Holocene. According to the model, the forest-to-non-forest and steppe-to-desert changes in the climate transition zones are spatially not uniform and not linear since the mid-Holocene. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 643 KW - Last Glacial Maximum KW - Eastern Continental Asia KW - summer monsoon precipitation KW - PMIP2 coupled simulations KW - Global Vegetation Model KW - northern high‐latitudes KW - Holocene climate change KW - Tibetan Plateau KW - environmental changes KW - Inner Mongolia Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418755 SN - 1866-8372 IS - 643 SP - 107 EP - 134 ER - TY - GEN A1 - Cao, Xianyong A1 - Herzschuh, Ulrike A1 - Ni, Jian A1 - Zhao, Yan A1 - Böhmer, Thomas T1 - Spatial and temporal distributions of major tree taxa in eastern continental Asia during the last 22,000 years T2 - The Holocene N2 - This study investigates the spatial and temporal distributions of 14 key arboreal taxa and their driving forces during the last 22,000 calendar years before ad 1950 (kyr BP) using a taxonomically harmonized and temporally standardized fossil pollen dataset with a 500-year resolution from the eastern part of continental Asia. Logistic regression was used to estimate pollen abundance thresholds for vegetation occurrence (presence or dominance), based on modern pollen data and present ranges of 14 taxa in China. Our investigation reveals marked changes in spatial and temporal distributions of the major arboreal taxa. The thermophilous (Castanea, Castanopsis, Cyclobalanopsis, Fagus, Pterocarya) and eurythermal (Juglans, Quercus, Tilia, Ulmus) broadleaved tree taxa were restricted to the current tropical or subtropical areas of China during the Last Glacial Maximum (LGM) and spread northward since c. 14.5 kyr BP. Betula and conifer taxa (Abies, Picea, Pinus), in contrast, retained a wider distribution during the LGM and showed no distinct expansion direction during the Late Glacial. Since the late mid-Holocene, the abundance but not the spatial extent of most trees decreased. The changes in spatial and temporal distributions for the 14 taxa are a reflection of climate changes, in particular monsoonal moisture, and, in the late Holocene, human impact. The post-LGM expansion patterns in eastern continental China seem to be different from those reported for Europe and North America, for example, the westward spread for eurythermal broadleaved taxa. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 417 KW - China KW - Holocene KW - Last Glacial Maximum KW - pollen mapping KW - vegetation expansion Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-404176 VL - 25 IS - 1 ER - TY - JOUR A1 - Cao, Xianyong A1 - Herzschuh, Ulrike A1 - Ni, Jian A1 - Zhao, Yan A1 - Böhmer, Thomas T1 - Spatial and temporal distributions of major tree taxa in eastern continental Asia during the last 22,000 years JF - The Holocene : an interdisciplinary journal focusing on recent environmental change N2 - This study investigates the spatial and temporal distributions of 14 key arboreal taxa and their driving forces during the last 22,000 calendar years before ad 1950 (kyr BP) using a taxonomically harmonized and temporally standardized fossil pollen dataset with a 500-year resolution from the eastern part of continental Asia. Logistic regression was used to estimate pollen abundance thresholds for vegetation occurrence (presence or dominance), based on modern pollen data and present ranges of 14 taxa in China. Our investigation reveals marked changes in spatial and temporal distributions of the major arboreal taxa. The thermophilous (Castanea, Castanopsis, Cyclobalanopsis, Fagus, Pterocarya) and eurythermal (Juglans, Quercus, Tilia, Ulmus) broadleaved tree taxa were restricted to the current tropical or subtropical areas of China during the Last Glacial Maximum (LGM) and spread northward since c. 14.5kyr BP. Betula and conifer taxa (Abies, Picea, Pinus), in contrast, retained a wider distribution during the LGM and showed no distinct expansion direction during the Late Glacial. Since the late mid-Holocene, the abundance but not the spatial extent of most trees decreased. The changes in spatial and temporal distributions for the 14 taxa are a reflection of climate changes, in particular monsoonal moisture, and, in the late Holocene, human impact. The post-LGM expansion patterns in eastern continental China seem to be different from those reported for Europe and North America, for example, the westward spread for eurythermal broadleaved taxa. KW - China KW - Holocene KW - Last Glacial Maximum KW - pollen mapping KW - vegetation expansion Y1 - 2015 U6 - https://doi.org/10.1177/0959683614556385 SN - 0959-6836 SN - 1477-0911 VL - 25 IS - 1 SP - 79 EP - 91 PB - Sage Publ. CY - London ER -