Sensitivity of temperate vegetation to Holocene development of East Asian monsoon

Estimating vegetation sensitivity during the Holocene will improve the predictions of future vegetation dynamics. We compiled 52 pollen sequences from the monsoon-influenced northern China to reconstruct the Holocene dynamics of three forest types dominated respectively by Pinus, Quercus and Betula, as well as steppe and desert indicated respectively by Artemisia and Chenopodiaceae. The sensitivities of these vegetation types to changes in intensity of the East Asian monsoon were calculated according to the elevation, temperature and precipitation groupings of sites. Our results show that the Holocene vegetation dynamics differed across vegetation types, with Pinus and Quercus at lower elevations more sensitive to monsoon-induced precipitation changes and Betula at higher elevations more sensitive to temperature changes at the beginning of the Holocene. We also found an increasing sensitivity for forests and steppe within different groups following evident reduction in monsoon intensity since 5 ka BP, caused most probably by climate drying in this drought-determined forest-steppe in northern China. Besides regional scale forest retreat caused by climate drying, elevational movement as well as site expansion and decline are also suggested to explain low vegetation sensitivities in some site-groups. Our study provides insights into the mechanisms of individualistic responses of plant taxa as well as the asymmetrical response of ecotonal vegetation to the Holocene monsoon development in China. (C) 2014 Elsevier Ltd. All rights reserved.