Anthropogenic disturbance to vegetation during the Holocene: Evidence from pollen spectra in China

Pollen is a crucial proxy for reconstructing the history of vegetation evolution and anthropogenic disturbance, offering critical insights into human-environment interactions. However, the interpretation of early disturbance signals and pronounced impacts remains ambiguous across individual pollen records. Additionally, integrated studies often overlook the nuanced interpretations presented in original records. This study systematically reviews 104 pollen records associated with anthropogenic disturbance across China. Based on the timing of disturbance identified in the original studies and the associated responses of pollen assemblages, we distinguish a “signal phase” and an “impact phase” of anthropogenic disturbance and analyze their spatiotemporal distribution patterns. The first signal phase is identified at 11.3 cal kyr BP in central east China, but more typically at around 8 cal kyr BP. In northeast China, it generally appears after 2 cal kyr BP, whereas its onset in other regions shows no pronounced spatial trend. The impact phase began around 6 cal kyr BP, with an increase around 4 cal kyr BP. In forest regions, there is a significant increase in records showing signs of impact at 2–1 cal kyr BP. Since 1 cal kyr BP, the impact phase also increased in western China. Arboreal taxa exhibit regionally distinct responses during the impact phase. In northeast China, Pinus declines notably, while widespread reductions in arboreal taxa are observed for northern China and the forest-steppe ecotone. Southern China shows decreases in native broadleaved trees accompanied by increases in Pinus, while mountainous areas in southwest China are characterized by increases in Alnus. Based on representative case studies, this study summarizes approaches to identifying anthropogenic disturbance from pollen assemblages, highlights divergent interpretations across studies as well as inconsistencies between pollen records and other proxy evidence, and outlines key challenges in pollen-based research on human activity.