Effects of Climate Factors on Ecosystem Health of Sandy Grassland in Hulunbuir

A healthy ecosystem is crucial for providing the services that humans need and has significant social and economic value. Evaluating the health of ecosystems is of great importance. In this study, ecosystem health index CVOR and its four component indexes (condition, vitality, organization and resilience) of Hulunbuir sandy grassland were calculated based on community characteristics and soil physical and chemical properties, and CVOR index was classified by Fisher ordered sample clustering method. The results show that the ecosystem health level of Hulunbuir sandy grassland was divided into four levels: level 1-healthy, level 2-sub-healthy, level 3-alert and level 4-collapse. There are significant differences in CVOR index and the four component indexes of the criterion layer and climate factors among different health level sites. Annual average temperature and growing season average temperature are negatively correlated with all health indices, while annual precipitation and growing season precipitation are positively correlated with all indices as well. This indicates that increased precipitation benefits the improvement of ecosystem health in Hulunbuir sandy grassland, while higher temperatures will hinder the maintenance of ecosystem health. Under the trend of global climate warming in the future, there is a risk of decreasing ecosystem health year by year in Hulunbuir sandy grassland. Grassland managers can maintain sustainable development of grassland ecosystem health by reducing grazing intensity and implementing other management methods.