Multiscale coupling characteristics and driving mechanisms of the production-living-ecological spaces in mountainous urban agglomerations

Rapid urbanization has intensified the conflicts among the production-living-ecological spaces (PLES), especially in mountainous urban agglomerations where complex terrain and ecological fragility lead to pronounced multi-scale spatial heterogeneity. Clarifying the coupling-coordination relationships and their driving mechanisms is essential for achieving refined territorial spatial governance. Taking the Central Yunnan Urban Agglomeration (CYUA) as a case study, this paper developed an integrated analytical framework combining multi-functional evaluation, coupling coordination degree modeling, and Geographical Convergent Cross Mapping (GCCM) to systematically examine the coupling characteristics and drivers across grid, township, and county scales. The results showed that PLES coordination had significant scale dependence, with the lowest coordination at the township scale due to concentrated heterogeneity, and the highest at the county scale driven by macro-level resource integration. As spatial scale increased, dominant driving factors shifted progressively from natural to socio-economic elements. At the grid level, factors such as NDVI and the proximity to cultivated land played key roles in promoting ecological stability and local coupling. At the township scale, road density and nighttime light indicated spatial accessibility and human activity intensity. At the county scale, per capita GDP, industrial agglomeration, and infrastructure development shaped spatial coordination through structural planning and institutional integration. Additionally, complex mountainous terrain moderated the transmission of spatial effects across scales, amplifying spatial fragmentation and functional isolation. Based on these findings, this study proposed a multi-scale collaborative governance strategy of "grid monitoring-township regulation-county integration". These findings offer both theoretical insights and practical strategies for enhancing spatial coordination and promoting sustainable development in topographically constrained and ecologically sensitive mountainous regions.