The improved LPJ model was used to investigate plant functional type (PFT) changes in 1957–2009 and their responses to changes in root zone soil temperature, soil moisture, air temperature, precipitation, and CO2
concentrations. The results show spatially heterogeneous changes in PFTs in the northern Tibetan Plateau in 1957–2009. Dominant driver for PFT change is precipitation. The implications of the study are on the regional fresh water resources, onset, and intensity of monsoon circulations.