500-Year Periodic Vegetation and Monsoonal Climate Oscillations During the Last Deglaciation in East Asia

Abstract

Fluctuations in monsoonal climate on orbital- to millennial-timescales have had a major impact on vegetation change in East Asia since the last deglaciation. However, the influence of centennial-scale oscillations on the spatio-temporal characteristics of vegetation and climate during the last deglaciation remains controversial. We present a well-dated, decadal-resolution pollen record from the sediments of annually laminated Lake Xiaolongwan in Northeast Asia, which reveals major orbital-/millennial-scale and minor quasi-periodic, that is, ∼500-year (yr) cyclic, vegetation changes from ∼19.96 to ∼10.79 Kyr ago (covering the last deglaciation). The ∼500-yr cycles are characterized by alternations in broadleaved forest/boreal coniferous forest with tundra steppe representing warm and humid/cold and dry phases of the monsoonal climate. This cyclicity may be related to El Niño-like/La Niña-like state and low-latitude atmosphere-ocean processes, against the background of the long-term trend of the deglacial climatic evolution. Our findings demonstrate a close relationship between ecosystem succession and climate change on centennial scale.