Spatiotemporal differentiation and geographic detection mechanism of ecological security in Chongqing, China

Ecological security is characterized by regional differentiation. Research on the spatiotemporal differentiation and mechanisms of ecological security across different regions plays an important role in ecological management and sustainable development. Taking Chongqing as our study area, and based on natural and socioeconomic data, we used spatial statistics and geographic detectors to explore the spatiotemporal differentiation characteristics and mechanisms of ecological security in Chongqing during the period 2000–2020. Our results show that ecological security in Chongqing was in a critically secure state. It exhibited an overall downward trend with the characteristics of an upward trend in 2000–2010 and a downward trend in 2010–2020. The improved area comprised 19,994.74 km² (24.27% of the land area) between 2000 and 2020, and this was mainly distributed in the northeast and southeast of the region, while areas of deterioration were mostly concentrated in urban residential zones, traffic arteries, and surrounding areas. Ecological security had clear spatial agglomeration characteristics. High value areas of ecological security were concentrated in the southeast and northeast, while low value areas were primarily found in the western cities and the core areas of socioeconomic development. The geographic detection mechanism suggests that among 17 key factors, the human disturbance index, land use degree, regional development index, biological abundance index, elasticity of the eco-environmental system, and the ecosystem service value contributed more than 50% of the spatial differentiation in ecological security. Thus, these six factors dominated the spatial differentiation. There were 40 main interactive combinations of four categories with q values > 0.7 in our interaction detection. The interactive synergy of terrain relief, human disturbance index, and land use degree enhanced the interpretation of the spatial differentiation of ecological security. Overall, this study refined the research scale to the grid unit, uncovered the leading factors and their interaction effects on ecological security, and provided a theoretical basis for the regulation of the ecological security of mountainous regions according to local conditions.