Identification of priority areas for ecological restoration based on evaluation of ecosystem service bundles：taking Changsha City as an example

In order to quickly and effectively divide the priority of ecological restoration in Changsha City, a research framework for identifying the priority areas of territory space ecological restoration in the system of "ecosystem service bundle-urbanization intensity" was constructed. By using the calculation model of ecosystem service value, cluster analysis, linear regression model and spatial statistics, the ecosystem service bundles in the study area were indentified, as well as the evolution of the comprehensive service capacity of ecosystem service bundles and the change of urbanization intensity were analyzed by spatial statistics. The priority areas of ecological restoration in the study area were identified in turn, and ecological restoration and protection strategies were put forward. The results showed that urban expansion heavily encroached on the surrounding land, resulting in 1821 grids (accounting for 20.15%) of the four ecosystem service bundles in the main urban area of Changsha City changing their service bundle types from 2000 to 2020. Urban expansion destroyed the original ecological environment and landscape pattern, which made urbanization always have a negative impact on the development of ecosystem service bundles, and the negative impact became more and more obvious with the acceleration of urbanization. Ecological restoration priority areas were divided into five grades, and 2609 grids (accounting for 28.87%) needed ecological restoration, of which 13.53% were classified as Grade Ⅰ ecological restoration priority areas, with Grade Ⅱ accounting for 0.58%, Grade Ⅲ accounting for 12.53%, and Grade Ⅳ accounting for 2.23%. Priority areas of Grade Ⅰ and Ⅲ ecological restoration paid attention to the promotion of key ecosystem services, while those of Grade Ⅱ and Ⅳ ecological restoration and ecological protection areas paid attention to the maintenance of existing ecosystem services. This method could quickly locate the areas where high-speed urbanization and ecosystem damage occurred at the same time, and provide reference for the formulation of different zoning restoration strategies, which can improve the ecosystem service capacity and reduce the negative impact of urbanization on the ecosystem.