Abstract: A large number of ecological restoration projects have been implemented in the semi-arid coal mining subsidence areas in China. Revealing the carbon sequestration capacity and influencing factors of vegetation in ecological restoration areas is of great significance for vegetation management and carbon sequestration assessment. Using ground surveys and unmanned aerial vehicle remote sensing methods, we established a model for measuring vegetation carbon sequestration in Daliuta Coal Mine in Shendong mining area and identified the main influencing factors at the scale of ecological restoration engineering. The results showed that: (1) The average carbon sequestration of restored vegetation reached 13.70 t·hm^-2, which was 4.14 times that of the original landform plant community. (2) Canopy water content, leaf nitrogen/phosphorus ratio, and plant configuration were the main influencing factors of vegetation carbon sequestration. There was a strong interaction between canopy water content and leaf nitrogen/phosphorus ratio and other factors, which significantly enhanced the influence of other factors on vegetation carbon sequestration. (3) There were threshold effects in the relationships between ground curvature, plant density, and plant diversity and the carbon sequestration capacity of vegetation. Concave terrain with negative curvature was conducive to vegetation carbon sequestration, while lower or higher plant density and moderate levels of plant diversity were unfavorable to vegetation carbon sequestration. (4) The simple structure of plant configuration, low nutrient availability, and plant density constraints were the main ecological risks faced by vegetation carbon sequestration in this area. Overall, semi-arid coal mining subsidence areas have great potential for carbon sequestration. In the future, long-term monitoring and adaptive management of vegetation after ecological restoration should be strengthened. The results can provide scientific basis for the rational implementation and effectiveness evaluation of ecological restoration in coal mining areas.

Key words: ecological restoration, unmanned aerial vehicle, carbon sink, vegetation, coal mining area