Abstract:
Exploring the carbon sequestration capacity of tailings ponds under different vegetation configuration scenarios is crucial for enhancing carbon sink capacity of tailings ponds in China, optimizing reclamation methods, and informing ecological environment management decisions. Using the InVEST model, four scenarios of vegetation configuration were proposed: natural recovery, low human intervention, medium human intervention and strong human intervention. The carbon sequestration potentials and spatial distribution characteristics of Chinese tailings ponds (excluding Hong Kong, Macao, and Taiwan regions data) under these scenarios were predicted. Additionally, the economic value of carbon sequestration in ecological restoration of tailings ponds was calculated, and the sensitivity of carbon price fluctuations on the economic value of carbon sequestration potentials was analyzed across the different scenarios. The study shows that: (1) The carbon sink potential of tailings ponds in China under the natural restoration, low anthropogenic intervention, medium human intervention and strong human intervention scenarios are 1.45×10
8, 1.79×10
8, 2.38×10
8, 2.65×10
8 t, respectively in 2035. The strong human intervention scenario demonstrates the highest carbon sequestration potential, accounting for 39.49% of carbon emissions from the mining industry. (2) The spatial distribution characteristics of the four scenarios are similar, with high-value carbon sink areas located in Xinjiang Uygur Autonomous Region, Hebei Province, Gansu Province, and Liaoning Province, which together account for 69.05% of the national tailings pond carbon sink potential. (3) The economic value of carbon sequestration for the four scenarios, based on the domestic carbon price, was calculated as 246.5×10
8, 304.3×10
8, 404.6×10
8 and 450.5×10
8 RMB, respectively. The highest value represents approximately 3.75% of the mining industry's profits. (4) The economic value of carbon sequestration is highly sensitive to changes in the carbon market price, with the balance point between economic benefits and costs being 63.75 RMB/m
2. Therefore, future ecological reclamation of tailings ponds should adopt a multi-level vegetation configuration to enhance the carbon sequestration capacity. Government agencies should continue to promote the re-greening and re-cultivation of tailings ponds, and gradually increase the carbon price to incentivize companies to independently carry out reclamation efforts.