Abstract:

Alpine wetlands serve as substantial carbon sinks and play a crucial role in providing habitats for wildlife and maintaining ecological security on the plateau. Current research predominantly focuses on areas below 4 000 meters in altitude, while studies on the surface soil organic carbon (SOC) of alpine wetlands above 4 000 meters require further enhancement. In this study, we analyzed the spatial distribution of surface SOC contents and their proportions in the total carbon of alpine wetlands. We utilized samples from 20 monitoring sites (with 3 replicates at each site) in the Chadan wetland, the highest-elevation wetland (average elevation over 4500 m) in the source region of the Yangtze River. Additionally, we explored the spatial differences among different tributaries. Results indicated that the surface SOC content in the Chadan wetland ranged from 0.54% to 18.47%, with an average of 4.78%. Moreover, its proportion in the total carbon exceeded 80%. The spatial correlations of total carbon and total organic carbon in tributaries on the north and south banks are opposite. This study advanced our understanding of the spatial distribution of surface SOC in alpine wetlands and provided preliminary exploration and validation data for more accurate estimations of carbon sink storage in high-altitude alpine wetlands.

Key words: headwaters of the Yangtze River, alpine wetland, Chadan wetland, total organic carbon, Carbon occurrence