A GMOP-PLUS-InVEST-GWR Coupled Model for Simulating “Production–Living–Ecological” Functions and Carbon Stock Dynamics in the Chengdu Metropolitan Area

Terrestrial carbon stocks have a substantial effect on the global carbon balance and promoting regional sustainable development. In the midst of growing urbanisation, the Chengdu metropolitan area—a key development pole in western China—has seen a radical reworking of its Production–Living–Ecology (PLE) functional framework. This transition has had a significant impact on the spatiotemporal dynamics of carbon stocks, but the fundamental mechanisms have yet to be comprehensively understood. To address this, this study constructed a GMOP-PLUS-InVEST-GWR coupled model to simulate and analyze the spatiotemporal evolution relationship between PLE functions and carbon stocks under multiple scenarios from 2000 to 2035. Results indicate that the evolution of the PLE functions reveals a trend of enhanced living functions, diminished production functions, and a slight increase in ecological functions. This has resulted in an overall decrease in carbon storage of 1199.63 × 104 t. Simulations indicate that the Ecological Protection Scenario (EPS) represents the optimal pathway for achieving stable carbon sinks and sustainable system development. It maximizes ecological quality improvement (total increase of +454.74 km2 across Zone 5) while minimizing carbon loss (−418.38 × 104 t). Conversely, the Economic Development Scenario (EDS) would result in the greatest carbon loss (−613.18 × 104 t). The impact of PLE functions on carbon stocks exhibits spatial heterogeneity: residential functions show negative effects (coefficients: −1.16 to −2.30), ecological functions yield positive effects (coefficients: 0.87 to 1.65), while the influence of production functions gradually shifts toward enhancing carbon sinks, with positively correlated areas increasing to 81.15%. This study provides scientific basis and spatial decision support for coordinating land development and conservation in rapidly urbanizing regions and enhancing regional carbon sink functions.