## 5 Conclusions  
This study introduces a coupled model and a multi-driver framework to dynamically simulate the spatio-temporal patterns of CS across different scenarios. It also integrates the spatial response mechanisms underlying heterogeneity, aiming to enhance the effective management of CS in regions experiencing rapid slope deformation.  
1. Over the past two decades, CS in the BRB has risen by 558 tons, primarily driven by the conversion of arable land to woodland. Spatially, CS is higher in the western and northwestern parts of the area, whereas the eastern and northeastern areas exhibit lower CS levels. This distribution is highly consistent with the topographic characteristics and landscape pattern.
2. The variation trend for CS in different scenarios is significantly different. In the ND scenario, the disorderly expansion of economic land at the cost of ecological environment leads to excessive reduction of cultivated land and ecological land, and finally aggravates the loss of CS. At the same time, although the cultivated land protection policy has a certain positive effect, its long-term effect is uncertain, which may eventually lead to the decline in regional CS. On the contrary, strengthening ecological protection can effectively expand the area of forest and grassland, and reduce the encroachment of construction land on ecological land, thus significantly improving the regional carbon sink capacity and bringing significant environmental benefits.
3. Along the elevation gradient, CS has an inverted U-shaped relationship with the topographic gradient, showing a synergistic effect, and forming an obvious stepped spatial distribution. CS peaks between 2500 and 3300 m above sea level, with superior natural resources in areas with slopes of 27\({}^{\circ}\) to 40\({}^{\circ}\) and topographic relief of 700 to 1000, resulting in carbon accumulation. However, these steep slopes still require soil and water conservation, and EP projects to further enhance carbon sequestration capacity. Therefore, it is very important to conduct topographic gradient zoning management for steep-slope areas, and a long-term ecological monitoring system should be established to evaluate the effect of ecological protection measures and timely adjust management strategies.  
Through the spatial heterogeneity of CS driven by topographic gradients and the customization of ecological corresponding strategies combined with future scenarios, this study provides important insights for fine ecological management in similar areas with rapid slope deformation. Future work could further consider the interaction of soil type, latitude, and localization drivers, and explore optimal LU management options constrained by CS targets under the dual scenarios of economic growth and ecological conservation.  
Conceptualization, Z.Z.; methodology, W.W. and Z.Z.; software, W.W., G.L. and H.S.; formal analysis, W.W.; funding acquisition, Z.Z.; investigation, G.L., H.S. and C.D.; project administration, J.D. and Y.W.; supervision, Z.Z., J.D. and Y.W.; validation, Z.Z.; visualization, W.W. and Z.Z.; writing--original draft, W.W. and Z.Z.; writing--original review and editing, W.W. and Z.Z. All authors have read and agreed to the published version of the manuscript.  
Natural Science Research Project of Anhui Educational Committee (grant no. 2022 AH040111), National Natural Science Foundation of China (grant no. 42071085, 41701087), and the Strategic Research and Consulting Project of Anhui Research Institute of Engineering and Technological Development Strategy, Chinese Academy of Engineering (2023-02).  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.