Vegetation carbon sequestration at tourist sites: an improved CASA model and XGBoost-SHAP approach

Tourism carbon sinks are a crucial component in achieving low-carbon transition and maintaining ecological balance. This study applies an improved CASA model to estimate the vegetation carbon sequestration capacity of 656 tourist sites across three provinces in Southwest China for the years 2000, 2010, and 2020. By integrating the XGBoost-SHAP method, the driving effects of changes in carbon sequestration were further analyzed. The results show that regional vegetation carbon sequestration capacity exhibited an overall increasing trend, with the average sequestration per site in 2020 approximately 51.25 g/m2·a higher than in 2000. Carbon sequestration was jointly influenced by natural and tourism-related factors, with the impact of tourism factors becoming increasingly significant and showing clear threshold effects. Theoretically, this study advances the empirical application of the human–environment interaction framework in tourism research. Practically, it provides a scientific basis and actionable insights for achieving the dual-carbon goals of China’s tourism industry.