Meitan kexue jishu (Jan 2023)
Mechanism, potential and regulation of carbon sequestration and sink enhancement in ecological restoration of mining areas in the Loess Plateau
Abstract
The ecological environment of mining areas in the Loess Plateau is extraordinary fragile, so it is crucial to achieve the carbon neutral vision to scientifically understand the mechanism and potential of carbon sequestration and sink enhancement in ecological restoration of mining areas in the Loess Plateau. Therefore, it is necessary to explore the key processes of carbon sink formation, the adaptability and resilience of restoration, and the potential of increasing carbon sink in the ecological restoration of the mining area in the Loess Plateau, as well as reveal the stability mechanism of the carbon pool in the reclaimed soil of the mining area. Finally, the key technologies of carbon fixation and sink enhancement in the ecological restoration of the mining area are clarified and elucidated. The results showed that: ① The critical processes of carbon sink formation in ecological restoration of mining areas in the Loess Plateau included plant photosynthetic carbon allocation, soil carbon sequestration, microbial carbon sequestration, soil respiration and so on; ② The ecological restoration adaptability of the mining areas in the Loess Plateau generally presented a trend of high in the southeast and low in the northwest, while the areas with poor adaptability were mainly distributed at the border between northern Shanxi and Inner Mongolia, as well as between central Ningxia and Inner Mongolia. The order of ecological resilience of typical mining areas was shown as follows: Mixed forest (43.2%-100.0%) > Broad-leaved forest (49.2%-83.2%) > Coniferous forest (47.9%-76.5%) > Grassland (39.1%-70.7%) > Shrub grassland (43.0%-69.0%). There was a positive correlation between the remediation years and soil carbon sink potential. The highest carbon sink potential generally occurred at 10-15 years of restoration. The mixed forests spent the longest ecological restoration time, but possessed the largest carbon sequestration potential; ③ The stability mechanism of reclaimed soil carbon pool was related to litter decomposition, clay mineral interaction, aggregate physical protection and microbial regulation; ④ The coupling repair technology including landform reconstruction, soil reconstruction, pioneer plant/microorganism and exogenous material is the optimal path for ecological restoration of coal mining areas in the Loess Plateau to fix carbon and increase carbon sink, and it is also conducive to the long-term stability and improvement of carbon sink.
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