Vulnerability of the terrestrial ecosystem to climate change in China

Climate change has significant impacts on the structure and stability of terrestrial ecosystems. China has implemented several restoration projects since the mid-20^th century and has experienced a substantial greening trend under climate change. However, the assessment and evaluation of the ecosystem vulnerability in China remains limited. Here, we evaluated the characteristics of ecosystem vulnerability from 1982 to 2020 in China in terms of its exposure, sensitivity, and resilience based on a multiple auto-regression approach. We analyzed the drivers and mechanisms of ecosystem vulnerability from multiple perspectives in different land cover types and climate zones. The results show that ecosystem vulnerability follows a similar spatial pattern to the exposure risk, especially in the eastern plains where the flat topography leads to the relatively higher climate risk. The agro-pastoral ecotone shows relatively high vulnerability due to higher exposure and sensitivity to climate change. The terrestrial ecosystem becomes more vulnerable to climate change when warming rates exceeding 0.04 ^oC/a and precipitation decrease for more than -5 mm/a. For different land cover types, croplands and forests show relatively high vulnerability and are attributed mostly to exposure and sensitivity respectively. Although grasslands show medium vulnerability on average, their sensitivity to climate change shows greater spatial variation. The transition zone between semi-arid and sub-humid climates is more vulnerable to climate change, but the humid region displays lower exposure and sensitivity because of sufficient water supply hence low sensitivity to precipitation change. Higher variability in temperature and precipitation in high-exposure and high-sensitivity areas compared to low-exposure and low-sensitivity areas, but higher variability in NDVI is mainly found in low-resilience areas. This study contributes to the understanding of terrestrial ecosystem vulnerability in China and highlights the urgency of climate mitigation actions.