关键词: 青藏高原, 返青期, 气温, 降水, Tibetan Plateau, vegetation regreening, air temperature, precipitation

Abstract: Detecting the growing season variability of terrestrial vegetation is crucial for identifying responses of ecosystems to recent climate change. Based on the normalized difference vegetation index (NDVI) and the air temperature and precipitation data, we have extracted the commencement of growing season (CGS) and the commencement of dekadly average temperature (CDAT) of 0 and 5℃ at typical weather stations on Tibetan Plateau from 1982-2009, and analyzed their spatiotemporal changes and the relationships between the CGS of vegetation and the air temperature and precipitation of winter and spring. The results show: the CDAT of 0 and 5℃ on the whole showed an advanced tendency, and the tendency of 5℃was more significant than that of 0℃; the multiple years average of CGS near typical weather stations gradually delayed from south to north and from east to west, and from 1982 to 2009, the CGS displayed an advanced tendency at all typical weather stations; and the CGS had a negative relation with the air temperature and precipitation of winter and spring, furthermore, the correlation of CGS with temperature was stronger than with precipitation. Different seasonal temperatures had different effects on CGS and the winter temperature affected CGS more than spring temperature.