Abstract: Guizhou Province is an important ecological barrier in the upper reaches of the Yangtze River and the Pearl River. Karst landform in Guizhou is developed, with fragile ecological background. The ecological risk assessment and control of Karst landform are of great significance to ecological security and sustainable development of southwest China and the upper reaches of those two rivers. Based on the InVEST model and vigor-organization-resi-lience model, we quantitatively evaluated the ecosystem services and ecosystem health and constructed the ecological risk assessment model of Guizhou Province. With the help of GIS technology, spatial autocorrelation analysis method and gravity center migration model, we analyzed the spatial and temporal variations of ecological risk in Guizhou Province from 2000 to 2020. The results showed that ecosystem services in Guizhou Province increased from 2000 to 2020, with an annual average growth rate of 0.3%. The ecosystem health status was generally well and showed a good trend, and the annual average growth rate of ecosystem health was 12.6%. The ecological risk was dominated by medium ecological risk. The proportion of extremely low ecological risk area and low ecological risk area increased, the proportion of medium and above ecological risk area decreased, and the overall ecological risk showed a downward trend. The low ecological risk areas were mainly located in the south and southeast of Guizhou Province, while the high ecological risk areas were distributed in the central, western and northern parts of Guizhou Province. The global Moran's I of ecological risk in 2000, 2005, 2010, 2015, and 2020 were 0.856, 0.836, 0.844, 0.804, and 0.768, respectively, indicating that the positive correlation of ecological risk in spatial distribution, but the spatial correlation and spatial agglomeration characteristics were weakened. During the study period, the centroid and trajectory of ecological risk in Guizhou Province were consistent with the distribution area of its corresponding ecological risk. From 2000 to 2020, the spatial distribution pattern of ecological risk in Guizhou Pro-vince was relatively stable. With the evolution of time, the dispersion of spatial distribution of extremely high ecological risk and low ecological risk increased. Ecological risk assessment based on ecosystem services and ecosystem health would provide scientific basis for regional ecological risk management and control.

Key words: ecosystem service, ecosystem health, ecological risk, InVEST model, vigor-organization-resilience model, Guizhou Province