资源环境科技发展态势分析平台

The use of pollen analysis to reconstruct regional vegetation changes, and subsequently climate, is a common approach in paleoclimatic reconstruction. However, it is unclear whether or not vegetation exhibits a lagged response to climate change during shifts from rapid cooling to rapid warming. The Younger Dryas (YD) cold event, spanning the last glacial/Holocene transition, was a prominent abrupt climatic event. To investigate the vegetation response to climate change during the YD, we compared profiles of independent climatic indicators from the sediments of alpine Lake Gonghai, on the margin of the modern Asian summer monsoon, with a pollen record from the same site. Our aim was to assess the phase lag of vegetation change relative to independent climate proxies that would have responded near instantaneously to climate change. The results show that the vegetation changed synchronously with the climate proxies, and consequently, we conclude that vegetation succession around Lake Gonghai exhibited a nonlagged response to climate change during the YD. This result confirms that a previous pollen-based quantitative regional precipitation record from Lake Gonghai reliably depicts variations in the East Asian summer monsoon (EASM), especially its decreasing trend during the YD. This conclusion differs from that of related research on the Baxie loess section and Hani peat deposits. Also, we suggest that our findings provide an improved understanding of the likely response of the EASM during cooling intervals and that the YD is a useful analog for studying the response of vegetation to possible abrupt cooling events under future global warming scenarios.