Responses of vegetation activity to climate variation on the Qinghai-Tibetan Plateau (China) from 1982 to 2011

The response of vegetation activity to variations in cloud cover, temperature, and precipitation on the Qinghai-Tibetan Plateau from 1982-2011 was analysed using the third generation Normalized Difference Vegetation Index (NDVI-3g) and Climatic Research Unit (CRU) dataset. There was no significant correlation between growing season cloud cover and vegetation growth (p > 0.1) over the Plateau. However, both temperature and precipitation were positively and significantly correlated with vegetation growth (p < 0.1), although these correlations varied among the different sub-regions of the Plateau. For instance, in higher altitude and latitude regions (where temperatures are lower), there was a significant correlation between temperature and NDVI series during the growing season (p < 0.1), whereas the other climate factors were not significantly correlated with vegetation dynamics (p > 0.1). In sub-regions with lower altitude or latitude (where temperature is not the limiting climate factor), precipitation variations had an important influence on vegetation activity. The time lag between precipitation variations and changes in vegetation dynamics differed between those sub-regions of the Plateau with different plant species and soil properties. In the warm and humid region, vegetation activity was less sensitive to all of the climate factors compared with the other regions.