Identification and optimization of ecological network in the plain area of the lower Yangtze River: A case study of Jintan District, Changzhou

Identification and optimization of ecological networks is an important research method to ensure the regional ecological security pattern and carry out the ecological protection and restoration of national land space. Based on theories of graph and landscape ecology, this paper took Jintan District in the lower reaches of the Yangtze River as an example, and used the remote sensing images, land use data, POI data, etc. Through the minimum area threshold and the optimal distance threshold analysis, the current ecological network of the region was identified, the ecological network under the guidance of the ecological blind zone was carried out, and the ecological network performance before and after optimization the importance of regional habitat patches was evaluated. This paper obtained the following results:(1) under the guidance of the ecological blind zone, ecological network optimization can significantly improve the connectivity of regional landscape and has strong applicability in ecological water network areas.(2) There are ecological landscape fractures in some areas of research area, and the ecological network layout needs to be optimized. The optimized Harary index increased by 10.92 times. The overall connectivity index increased by 43.45%, and the possibility connectivity index increased by 99.58%.(3) National land space ecological protection and restoration should focus on key areas, and adopt the strategies of important patches ecological protection, key nodes ecological restoration, and special regions ecological construction for ecological network restoration.