Construction of an ecological security network in the Fenhe River Basin and its temporal and spatial evolution characteristics

Based on morphological spatial pattern analysis and ecosystem service value accounting, in this study, we screened ecological sources, identified ecological corridors using circuit theory, and constructed an ecological security network (ESN) of the Fenhe River Basin from 2000 to 2019 as well as analyzed its spatial and temporal evolution characteristics. The results revealed that the percentage of the ecological sources area of the Fenhe River Basin decreased from 13.33 to 12.51% from 2000 to 2019, and the mountainous and basin areas of the Fenhe River Basin were densely and sparsely distributed, respectively. Ecological resistance value revealed high and low spatial patterns in the middle and surrounding areas, respectively. Mountain and basin ecological resistance was low and high, respectively, and the spatial range gradually expanded. The ecological corridors decreased in number from 26 to 13, and were mainly distributed in the mountains on both sides of the basin. The number of corridors in the basin was small, and the distribution was tortuous. The northern and southern ecological corridors were dense and sparse, respectively. The Fenhe River Basin ESN had a dense and sparse spatial pattern in the north and south, respectively. The key ecological pinch point and ecological barrier restoration areas were mainly distributed around the ecological protection corridors within the basin and changed frequently. The key ecological protection and key ecological improvement areas increased with gradual improvements in the ESN. The basin area is the key area of ESN connectivity in Fenhe River Basin, and the improvement and restoration of the ecological environment in the basin plays a key role in maintaining the overall ESN. Natural and human factors affect the ESN of the Fenhe River Basin, exhibiting the characteristics of the basin units in the mountainous areas and administrative region units in the basin regions, which is a distinctive spatial characteristic of this ESN compared to other regions.