[Carbon Stock Changes and Multi-scenario Prediction in the Sichuan-Chongqing Region Based on PLUS-InVEST Modeling]

Carbon stocks in terrestrial ecosystems are significantly affected by land use/cover change （LUCC）， and exploring the role of LUCC on carbon stocks of regional terrestrial ecosystems is of great importance for improving land use structure and achieving the goals of carbon peaking and carbon neutrality. Based on the land use data between 2000 and 2020， this study established four development scenarios， namely natural development （ND）， ecological protection （EP）， economic development （ED）， and comprehensive development （CD）， by integrating 13 key drivers. Combined with the PLUS and InVEST models， the dynamic adjustment of land use types and the spatial and temporal evolution of carbon stocks in the Sichuan-Chongqing Region were simulated. The study findings revealed that： ① From 2000 to 2020， the areas of grassland and cropland decreased by 83.65×10⁴ hm² and 46.41×10⁴ hm²， respectively， while the areas of forest land， construction land， and water increased by 65.37×10⁴， 50.55×10⁴， and 13.41×10⁴ hm²， respectively， and the area of unutilized land remained stable. ② In 2000， 2010， and 2020， the carbon stocks were 1 968.88×10⁷， 1 996.90×10⁷， and 1 998.59×10⁷ t， respectively， and the total carbon stock increased by 29.71×10⁷ t. The conversion of cropland and grassland to forest land was the primary driver for increased carbon stocks. ③ According to the study， compared to that in 2020， carbon stocks under the ND， ED， EP， and CD scenarios increased by 1.48×10⁷， 27.75×10⁷， 43.62×10⁷， and 50.32×10⁷ t， respectively. The CD scenario exhibited higher carbon stocks and a more excellent total value than the other scenarios， making it the optimal development model. The results of the study provide a reference for decision-makers on ecosystem carbon stock optimization from the perspective of land use， which will provide strong support for the formulation of future land use policies and the realization of the goal of carbon peaking and carbon neutrality.