Understanding the spatio-temporal characteristics of ecological degradation and its mechanism is the key to implementing national land space ecological restoration. Currently, there is a lack of knowledge about identifying ecologically degraded areas from a structure–function angle. This paper used the Dongting Lake Basin (DLB) as the research area, with the landscape pattern index and InVest model utilized to analyze the landscape distribution characteristics and ecosystem service functions in 2000 and 2018. Based on this, a fuzzy inference a...