Ecosystem health assessment based on ecological integrity and ecosystem services demand in the Middle Reaches of the Yangtze River Economic Belt, China

Ecosystem health assessment is vital for regional ecological restoration and management. Although many studies have improved the framework of ecosystem health assessment at the regional scale, most of them primarily focus on the single measurements of the natural states of ecosystems or external disturbances. However, there is a lack of comprehensive evaluation methods based on the ecological integrity and human demand for ecosystem services from the perspective of coupled human and ecological systems. In this study, we proposed an improved method that considers the ecological integrity and ecosystem services demand, which comprises four aspects of indicators: vigor, organization, resilience and ecosystem services (ES) supply-demand ratio. We used the Middle Reaches of the Yangtze River Economic Belt in China as a case study to apply the evaluation method. Our results indicate that (1) the level of ecosystem health is low in the middle of the study area and high on the periphery from 2000 to 2015. The moderate and good health levels dominate throughout the study area in 2000 and 2015. (2) The ES supply-demand ratio can objectively measure the actual status of ES, and the strong ES deficit aggravated dramatically the deterioration of regional ecosystems. (3) Urbanization exhibited a significant negative correlation with the ecosystem health index, and the greatest impact was observed in the urban agglomeration regions. Our framework extend the ecosystem health assessment methodology, and the research results can provide significant references for regional ecological protection and management.