Analysis on Ecological Vulnerability to Climate Change of Grasslands in Sichuan Northwestern Plateau

Grasslands in Sichuan Northwestern Plateau (GSNP), located in the south-eastern Tibetan plateau, is fragile and sensitive to climate change. GSNP, situated in the upper reaches of the Yangtze River and the Yellow River, is one of China’s five major pastoral areas. It plays a vital role in social and ecological fields. Therefore, it is pretty important to explore the ecological vulnerability to climate change in GSNP. In this study, based on long-term remote sensing data and meteorological data, we assessed ecological vulnerability of GSNP to climate change using indicators in the exposure-sensitivity-resilience framework. Our analysis indicated that (1) The vulnerability index was highest in the northwestern area, followed by that in the southeastern area, and was lowest in the middle area in GSNP. The spatial pattern of the exposure index determined that of vulnerability index in GSNP. (2) For various vegetation types in GSNP, the vulnerability index was highest in typical steppes and lowest in meadows and wetlands. The vulnerability index in alpine meadows was between the two. Differences of the vulnerability index among various vegetation types were determined by differences of the exposure index. (3) The spatial patterns of the vulnerability index in the subtropical climate zone were various from them in the alpine climate zone. In the subtropical climate zone, the vulnerability index was lowest in the middle subtropical climate region-dianbei. The vulnerability index in the middle subtropical climate region-sichuan and that in the northern subtropical climate region-qinba were at a comparable level. Differences of the vulnerability index among various climate zones were determined by differences of the resilience index in the subtropical climate region. In the alpine climate zone, the vulnerability index was highest in the alpine climate region-changdu, followed by the alpine climate region-bomi and chuanxi, and was lowest in the alpine climate region – qingnan. The spatial patterns of the vulnerability index were determined by the exposure index in the alpine climate zone. This study will be significant for ecological and environmental protection and the livestock husbandry development.