Abstract:Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.