An updated biomization scheme and vegetation reconstruction based on a synthesis of modern and mid-Holocene pollen data in China.

This paper presents an updated Taxa-PFTs-Biome scheme, based on 18 biomes, 30 Plant Functional Types (PFTs) and 590 pollen taxa from 1630 surface pollen sites in China. The biomization results reveal a total of 16 biome types comprising eight new biomes. By comparing the simulated biome types with modern potential vegetation, 80% of the sampling sites were correctly assigned, which is considerably more accurate than studies which have used previous Chinese biomization schemes. The biome reconstruction for the mid-Holocene (6 ± 0.5 14C kyr B.P.) shows that: (1) In eastern China, tropical, subtropical, warm-temperate and cool-temperate forests did not significantly expand northward, whilst cold-temperate forests were absent from northeastern China; and (2) in central China, the western boundary of steppe vegetation was shifted westwards due to a ~150–300 km extension of the forest and forest-steppe biomes, which is close to the present-day 200–300 mm isohyet. The northwestward shift of the forest and forest-steppe in central China during the mid-Holocene indicates that moisture levels were enhanced compared to the present day. The climatic mechanism responsible was likely a strengthened East Asian summer monsoon, which resulted in increased moisture transport from the ocean to the semiarid regions in northern China, promoting the development of forest and forest-steppe vegetation. • An updated taxa-PFTs-Biome scheme, based on 1630 surface pollen sites in China, was established. • The average accuracy of the updated scheme is more than 80%, which higher than previous Chinese schemes. • The boundary of the forest-steppe zone during mid-Holocene generally advanced northwestwards by about 200-300 km. [ABSTRACT FROM AUTHOR]