Responses of Carbon Sink of Ecosystem Vegetation to Land Use Changes in Kunming City

[Objectives] To analyze the relationship between the land use pattern and the carbon sequestration level of the ecosystem vegetation in Kunming City, and to provide a certain reference for optimizing the land ecological use pattern and scientific carbon reduction and sequestration. [Methods] Based on remote sensing data, meteorological data, vegetation data and soil data, the Carnegie-Ames-Stanford Approach (CASA) was adopted to estimate the vegetation net primary productivity (NPP) in Kunming during 2005-2020, and then the vegetation carbon sink was calculated through the plant mortality model. Besides, it established the land use transfer matrix of Kunming City, and analyzed the change characteristics of the carbon sink of ecosystem vegetation in Kunming City under the influence of land use changes. [Results] During 2005-2020, the water area, construction land and unused land area in Kunming increased by 43.52, 710.51 and 2.8 km2, respectively; farmland, woodland and grassland decreased by 269.72, 140.20 and 347.03 km2, respectively; farmland, woodland, grassland, water area, construction land and unused land caused a total of 58 212.72 t of vegetation net carbon sink loss in land conversion, accounting for 14.88%, 25.23%, 11.95%, 10.58%, 37.09%, and 0.26%, respectively.[Conclusions] This study is expected to help to improve the ecological carbon sequestration capacity of Kunming and promote the sustainable development of land resources.