Method for tracing source of grassland historical vegetation community

The invention discloses a method for tracing a grassland historical vegetation community, which comprises the following steps: determining the current vegetation community composition and spatial distribution in a grassland vegetation ecosystem, and the species composition in each community; determining historical vegetation community composition and spatial distribution in the grassland vegetation ecosystem, and species composition and regional spatial distribution in each community; determining a corresponding relationship between grassland history and current vegetation communities; preliminarily determining possible distribution of species in historical vegetation communities; establishing a historical vegetation community and species habitat feature database and a to-be-studied area natural geographic database; and finally determining the species composition of the historical vegetation community. The method is clear in principle and clear in action mechanism, has universality for grassland historical ve