Spatiotemporal Variations in the Carbon Sequestration Capacity of Plateau Lake Wetlands Regulated by Land Use Control under Policy Guidance

Lake wetlands play a crucial role in mitigating climate change. Human activities and climate change impact the carbon sequestration capacity of lake wetlands. However, this process is intricate. Clarifying the decisive factors that affect carbon sequestration is crucial for preserving, utilizing, and enhancing the carbon sequestration capacity of plateau lake wetlands. Here we analyzed the regulatory role of land use under policy guidance on the carbon sequestration capacity of the plateau lake wetland of Caohai (CHLW), SW China. The results show that: (1) The cumulative carbon sequestration varied significantly from 1990 to 2020, with the highest carbon sequestration of 15.80 × 10⁵ t C in 1995 and the lowest of 3.18 × 10⁵ t C in 2020, mainly originating from endogenous carbon sequestration within the plateau lake wetlands. (2) As of 2020, the carbon stock of CHLW was approximately 2.54 × 10⁸ t C. (3) The carbon sequestration in CHLW experienced a dynamic change process of decrease-increase-decrease over 30 years, mainly influenced by land use changes under policy regulation, with human and natural factors accounting for 91% and 9%, respectively. (4) Under three simulated scenarios (Q1, Q2, and Q3), the ecological priority scenario exhibited positive regulation on the carbon sequestration of CHLW and the entire protected area in 2030 and 2060, with the highest increase in carbon sequestration. This scenario is consistent with the current conservation policy, indicating that the current protection policy for CHLW is scientifically reasonable. This research demonstrates how land use and climate changes impact carbon storage in wetlands, with consideration of policy guidance. It provides references for utilizing and conserving lake wetlands worldwide, ultimately achieving the dual goals of wetland conservation and carbon neutrality.