[Spatiotemporal Dynamics of Land Use and Carbon Stocks Under Multiple Scenarios in the Yangtze River Basin]

China's Yangtze River Basin holds significant ecological and economic importance. Understanding land use dynamics and carbon stock changes in this region is critical for promoting sustainable development. This study examines the spatiotemporal evolution of land use and carbon stocks from 1985 to 2022 by integrating the FLUS and InVEST models. It further projects changes through 2050 under three scenarios：inertial development，ecological protection，and economic development. The results reveal that：① Land use changes demonstrated a dynamic interplay of cultivated land decline（-26.5%），ecological restoration（forest 11.2%，wetland 14 681 km²），and rapid urban expansion（impervious surfaces ×4.08）. ② Net carbon stock increased by 1.83×10⁹ t during 1985-2022，with marked temporal variability. Significant declines occurred in cropland（-16.8%）and forest（-11.6%）carbon stocks between 1995 and 2000，while recent gains were observed in woodland（30.7%）and grassland（6.3%）from 2020 to 2022. ③ Land use transitions played a pivotal role in carbon dynamics：Conversion from cropland to forest contributed 1.26×10⁹ t of carbon gain（42.7% of total），whereas urbanization-driven cropland loss led to a 3.98 × 10⁸ t decrease. Wetland restoration and woodland expansion contributed an additional 2.01×10⁸ t and 5.29×10⁹ t，respectively. ④ Scenario analysis indicated that ecological protection yielded the highest carbon accumulation（72.47×10⁸ t）through wetland（118.9%）and forest（8.3%）expansion. In contrast，inertial and economic development scenarios resulted in 9.1% and 5.8% reductions due to increased impervious surface area. Spatial analysis identified the Yangtze River Delta and the Chengdu-Chongqing urban clusters as major carbon loss hotspots. The findings underscore the importance of implementing ecological protection strategies，including stricter controls on agricultural land conversion and enhanced wetland and forest restoration，to bolster regional carbon sinks and support China's dual carbon goals.