Land-use-associated carbon storage variation in the Dashanbao Alpine wetland region: An InVEST-based assessment with soil profile interpretation

Carbon storage is an effective ecological indicator for assessing ecosystem changes associated with land-use dynamics, particularly in carbon-sensitive alpine wetlands. This study evaluated land-use-associated carbon storage changes in the Dashanbao alpine wetland region of southwestern China from 2000 to 2024 by integrating multi-temporal land-use data, the InVEST carbon storage model, land-use transition analysis, wetland-related ecological subzones, and soil profile observations. The results showed that land-use change was dominated by transitions among grassland, cropland, and forestland. Grassland area decreased from 130.60 km 2 to 92.48 km 2 , whereas cropland and forestland increased by 22.44 km 2 and 15.20 km 2 , respectively. Total carbon storage increased from 3.203 Tg in 2000 to 3.477 Tg in 2015, but subsequently declined to 3.116 Tg in 2024, indicating an overall net loss during the study period. Grassland remained the dominant carbon pool, but its substantial contraction was the main driver of regional carbon-storage decline. Transition-pathway analysis identified grassland-to-cropland conversion as the primary carbon-loss pathway, contributing −0.271 Tg, whereas grassland-to-forestland and cropland-to-forestland transitions generated carbon gains of 0.085 Tg and 0.050 Tg, respectively. Soil profile observations revealed significant vertical differentiation of soil organic carbon, with mean values decreasing from 49.01 g kg −1 at 0.5 m to 10.48 g kg −1 at 3.0 m, confirming a significant negative relationship with soil depth. These findings demonstrate that carbon storage can effectively reflect land-use-associated ecosystem changes in alpine wetlands. This study highlights the value of coupling InVEST-based carbon assessment with transition-pathway analysis and soil-profile evidence, and suggests that conservation should prioritize high‑carbon grasslands, wet meadows, peatland-related zones, and strict control of grassland-to-cropland conversion.