Construction of a Coupling Framework for Production-Living-Ecology Function Interactions: A Case Study of the Guizhou-Guangxi Karst Region, Southwest China

Karst regions face acute conflicts among production, living, and ecology (PLE) functions under the constraints of rugged terrain and rocky desertification. Existing studies have separately examined driving factors, interaction directions and intensities, and nonlinear thresholds, while how these dimensions co-evolve across space and time remains unclear. To address this gap, we used seven concentric buffers radiating from the built-up area as a spatial proxy for human activity intensity and constructed a framework within each buffer using Geodetector to identify core driving factors, Pearson correlation to quantify the direction and intensity of three pairwise interactions, and Pareto frontier analysis to capture nonlinear thresholds and tipping points. In the Guizhou-Guangxi karst region (2010–2019), the core drivers of production and ecology functions shifted from construction land through elevation to precipitation, while population consistently drove the living function. Along this gradient, the coupling relationships fluctuated in the core but improved in the periphery. Although trade-off intensities eased beyond 10 km, three Pareto frontier curves shifted from inverted-U patterns to monotonic trade-offs, indicating that this improvement was only quantitative while the interaction structure degraded. Tipping points disappeared in these curves, eroding the carrying-capacity buffers where win-win synergies remained attainable. Averaged correlation coefficients obscured this contrast between apparent improvement and structural degradation, and linear correlation analysis alone would not have detected it. These findings highlight the need for zone-specific management in karst regions, where monitoring based on Pareto-derived structural indicators can provide early warning of coupling degradation that averaged correlations mask.