Abstract: We analyzed the spatiotemporal variation of vegetation NDVI and its response to climate change in the temperate grassland region of China based on GIMMS NDVI and monthly climate data from 1982 to 2015. The results showed that the growing season NDVI of temperate grasslands in China showed an increasing trend (0.008 (10 a^-1)) during 1982-2015. In different seasons of the growing season, the NDVI of temperate grasslands in China generally showed an increasing trend, but with an obvious spatial heterogeneity. During the growing season, precipitation was the most important factor affecting vegetation growth of temperate grasslands. The increase of precipitation in the growing season (especially in spring and summer) significantly promoted the growth of temperate grasslands. In terms of temperature effects, the increasing night-time minimum temperature in spring was beneficial to the growth of temperate grasslands, while the increase of daytime maximum temperature in spring and autumn obviously promoted the growth of temperate meadow steppe and typical steppe. The daytime maximum temperature and night-time minimum temperature had asymmetric effects on temperate grasslands in summer. Specifically, the increase of daytime maximum temperature in summer could inhibit vegetation growth, while the increase of night-time minimum temperature in summer could promote the growth of temperate grasslands in China.

Key words: temperate grassland, vegetation, NDVI, climate change, response.