[Spatial-temporal Evolution of Ecological Security Patterns and Assessment of Ecological Resilience in Chongqing...

Establishing an ecological security framework and assessing ecological resilience are of great significance for enhancing regional ecological security levels and optimizing the spatial layout of mountainous urban areas. Taking Chongqing as an example， the InVEST model was used to assess four ecosystem services： water production， carbon sequestration， soil conservation， and habitat quality. The MSPA method was employed to identify ecological source areas. A resistance surface was constructed by comprehensively considering natural and human factors. The Linkage Mapper tool was utilized to extract ecological corridors and identify ecological bottlenecks， thereby constructing the regional ecological security pattern. Additionally， the Fragstats and Conefor Sensinode software were used to assess its ecological resilience. The results indicate that from 2000 to 2022， the number of ecological source patches continued to increase， with a spatial distribution characterized by concentration in the east and dispersion in the west. The total length of ecological corridors first increased and then decreased， with a net increase of 2 717.37 km， and the overall connectivity of the region gradually strengthened. The total area of ecological nodes showed a "V"-shaped trend， forming two high-density core areas in the Qinba Mountains of northeastern Chongqing and the Wuling Mountains of southeastern Chongqing. The ecological source area resilience index in Chongqing ranged from 0.087 5 to 0.897 4 between 2000 and 2022， with a spatial distribution pattern of "high in the northeast and low in the southwest." The ecological corridor resilience index ranged from 0.206 7 to 0.769 4， with low-resilience corridors concentrated in the Wuling Mountains in southeastern Chongqing and the Three Gorges Reservoir Area in northeastern Chongqing， while high-resilience corridors were distributed in the Daba Mountains， parallel ridge and valley areas， and the outskirts of the main urban area in northeastern Chongqing. The ecological node resilience index ranged from 0.216 9 to 0.783 1， with an overall spatial pattern characterized by "low resilience dominance and localized high resilience clusters." The research findings provide a scientific basis for optimizing ecological space， enhancing ecosystem stability， and improving ecological service functions in Chongqing and also offer reference and guidance for constructing ecological safety patterns and assessing regional ecological resilience in other mountainous cities.