Modern pollen assemblages in lake surface sediments and their relationships with vegetation, climate, and human activities in Yunnan, SW China

Modern pollen assemblages from moss polsters, topsoils, and lake surface sediments are crucial for interpreting palaeovegetational and palaeoclimatic conditions from fossil pollen records. While a large number of modern pollen assemblages exist from Yunnan Province, SW China, few are derived from lake surface sediments with depositional environments similar to those of fossil pollen records. In this study, we present modern pollen assemblages from lake surface sediments across 36 lakes in Yunnan, spanning spatially from the southeast to the northwest of the region. These lakes encompass a range of vegetation types, varying from alpine meadow grasslands to tropical seasonal and montane rainforests. Our findings demonstrate that modern pollen assemblages from lake surface sediments can effectively identify various vegetation zones. Redundancy analysis (RDA) reveals a strong correlation of pollen assemblages with climate factors (e.g., temperature and precipitation) but a weak correlation with human activities. This study suggests that modern pollen assemblages from lake surface sediments in Yunnan can be used not only to reflect changes in vegetation and climate, but also as reliable indicators for reconstructing the history of human activities to some extent.