Pollen analysis
Vegetation profiles derived from historical pollen analysis are also seen as a key tool in assessing historical climate trends and disturbances. Pollen analysis offers a historical record of vegetation profiles that are sensitive to abrupt changes in climate conditions. Therefore, historical climate events, including human-induced climate change, can shift vegetation profiles relatively rapidly compared to natural transitions. For example, the quantity of poplar pollen increased dramatically at the beginning and end of the Younger Dryas period, serving as a biological marker for that time period. Comparing historical vegetation profiles also allows researchers to compare successive changes in vegetation between two specific regions and correlate these differences with the corresponding climates of each region. A recent study conducted at Shudu Lake in the Hengduan Mountains of Yunnan, , southwestern China, was able to correlate changes in temperature and humidity with the development of needleleaf forests, as well as model recent anthropogenic effects on vegetation distribution in the area.