Abstract:

The frequency of various ecological problems and the disturbances caused by human activities have brought about significant changes in the structure and function of the ecosystems and affected the ecological security in western Jilin Province. The construction of ecological security patterns can effectively guarantee regional ecological security, which is especially important for the environmental improvement of ecologically fragile areas. Western Jilin Province is a typical ecologically fragile area in China and an important ecological barrier within Jilin Province. Taking western Jilin Province as the study area, four indicators (biodiversity service value, water security, soil conservation, and ecological demands) were selected to identify ecological sources through ecosystem importance evaluation and ecological demand analysis. We used circuit theory combined with the Linkage Mapper tool and Circuitscape software to identify ecological corridors, pinch point regions, and ecological improvement regions and to construct an ecological security pattern for western Jilin Province. On this basis, we then put forward a reasonable ecological security pattern protection strategy. The research results demonstrated the following: (1) There are 18 ecological source areas in the study area. These account for 8.57% of the study area, mainly in the wetlands around the existing protected areas. Ecological source areas within nature reserves should focus on further improving existing protection policies, and ecological source areas outside nature reserves should focus on strengthening protection. (2) There are 38 key corridors and seven potential corridors, mainly in the central and eastern regions. The corridors in the middle are distributed in a net-like pattern, and those in the east are scattered to provide room for animal migration. The pinch point region is relatively concentrated in the southwest and east to maintain landscape connectivity. The ecological improvement region has relatively high amounts of building land and saline land, and the southwestern and eastern areas have high improvement coefficients. The improvement areas can be divided into primary corridor ecological improvement regions and secondary corridor ecological improvement regions, with graded protection. (3) On the basis of constructing comprehensive ecological security patterns, such as ecological sources, corridors, pinch point regions, and ecological improvement regions, we put forward a targeted strategy regarding ecological security pattern called “one belt, two axis, five regions, and five groups”. In previous studies, only the construction of ecological sources has been considered, whereas the further construction of ecological corridors has been neglected. Still, the construction of ecological corridors based on circuit theory and the identification of pinch points and ecological improvement regions can improve the construction of ecological corridor systems. Circuit theory treats animal migration as a random change that is not predictive to the surrounding environment and is in line with the characteristics of animals themselves, and it identifies the structure of ecological corridors relative to reality. It can thus provide a new reference for the construction of ecological security patterns. Constructing a comprehensive ecological security pattern and proposing a reasonable conservation strategy will provide a reference for decision-making to ensure regional security and coordinated economic and ecological development in western Jilin Province.

Key words: ecological security pattern, circuit theory, ecological service functions, western Jilin Province