Rate of vegetation change in southeast China during the Holocene and its potential drivers

Understanding the factors behind past vegetation changes is instructive to anticipate how vegetation will react to future climate change and human activities. The factors that contribute to the changes in vegetation during the Holocene in the topographically diverse southeast China are still not well understood. This study presents a recently acquired subalpine pollen record and combines it with pollen records from low-lying areas and mountains in southeast China. We utilized a Rate of Change (RoC) analysis on the pollen sequences to detect shifts in vegetation composition. Our findings indicate a significant increase in vegetation rate of change in southeast China over the past 3000 years, comparable to or exceeding maximum levels seen during the early Holocene, a period characterized by greater climate variability. By analyzing available paleorecords of climate, fire, and human activity, it becomes clear that vegetation in southeast China was significantly affected by climate before c. 3 ka BP. However, after this time, human impacts began to play a prominent role, first in the lowlands and later in the mountains, in addition to the influence of climate variations. Our study emphasizes the significance of taking into account the rate of vegetation compositional change when examining the factors that influence long-term vegetation changes.