Construction and optimization strategy of ecological security pattern based on ecosystem services and landscape connectivity: a case study of Guizhou Province, China.

Rapid urbanization and irrational human activities have induced in numerous environmental problems, seriously threatening regional ecological security. The establishment and optimization of ecological security patterns (ESPs) were considered as a nature-based solution and an effective way for sustainable development. In this study, the Guizhou Province, a representative karst mountainous region in the southwest of China, was used as the study region. The ecological sources were identified and optimized through integrating ecosystem services and landscape connectivity, and the ecological resistance surface was corrected by representative features of karst areas. The circuit theory was adopted to extract the ecological corridors and barriers. We found that the three ecosystem services (i.e., water conservation, biodiversity maintenance, and soil conservation) had remarkable spatial heterogeneity. The area of optimized ecological sources was enlarged 4752.14 km. The number of corridors was reduced from 73 to 47 after optimization, with a total length decreased by 1251.97 km. The optimized ecological network structure considerably enhanced ecological connectivity, among the γ index increased by 0.0014, the β index reduced by 0.0833, while the α index did not change significantly. We concluded that quantitatively exploring the impacts of ecological source optimization are significant for enhancing ecological connectivity. The approach of our study proposes a novel idea into the ESP construction that can provide a meaningful reference for ecological protection and restoration.