露天煤矿复垦生态系统碳库研究进展

Research Advances in Carbon Sequestration of Reclaimed Ecosystems in Opencast Coal Mining Area

露天煤矿开采作为世界范围内的主要采煤方式，在满足人类能源需求和促进社会经济发展的同时，也造成矿区生态环境破坏和生态系统固碳能力退化。研究露天煤矿土地复垦过程中生态系统碳库动态变化不仅对认识区域碳平衡具有重要意义，该变化过程还可以作为露天煤矿土地复垦效果的重要判断指标。综述了国内外露天煤矿复垦林地、复垦草地以及复垦耕地生态系统碳库动态变化的研究。已有的研究成果表明，（1）露天煤矿复垦林地、复垦草地和复垦耕地生态系统土壤碳库均较自然恢复地要高，有的矿区甚至比原地貌要高。干旱区煤矿土地复垦初期以草地固碳效果较好，而半干旱和湿润区煤矿复垦以林地效果较好。同一生态系统，碳储量随植物物种及植物配置方式而异。（2）矿区土壤碳库呈现“U”型动态恢复过程。林地土壤有机碳年均增长量为0.20-6.27 Mg·hm-2；草地为0.30-3.37 Mg·hm-2；林草混合复垦模式为0.31-2.80 Mg·hm-2。（3）复垦林地生态系统碳库主要存储在植被中，而复垦草地则主要存储在土壤中。（4）土壤碳库主要受土壤理化性质、地上植被、复垦年限、立地条件以及复垦工艺等因素影响。因此，矿区土地复垦中应注重排土场微地形优化，筛选适宜物种，优化植被配置模式和改进复垦措施，以加快矿区复垦生态系统碳库恢复。针对露天煤矿生态系统碳库研究现状，提出未来我国露天煤矿复垦生态系统碳库的研究重点，包括加强植被碳库、土壤无机碳库及总碳库全生命周期研究，加强荒漠区露天煤矿碳库研究，以期为全面认识我国露天煤矿复垦生态系统碳库研究提供科学依据。

As the main way of mining in the world, large scale opencast mining caused great damage of land, which deteriorates our environment and disturbs the carbon sequestration of the ecosystems in the mining area. The dynamic change of ecosystem carbon pool is important to balance the regional carbon recycle and it is also an important index for judging the effects of land reclamation in opencast coal mine. In this paper, the studies on carbon pool of reclamation ecosystems in opencast coal mines were summarized and discussed. To sum up, we can draw the conclusion that： （1） Compared with the natural restored ecosystems, soil carbon storage of the reclaimed ecosystems, including forest land, grassland and farmland, were much higher. Moreover, soil carbon of few sites was even higher than that of the original landform ecosystems. Grassland was proposed to be a priority reclamation pattern for mines in arid area in terms of carbon sequestration, while reforest was recommended for mines in semi arid and wet regions. In addition, ecosystem carbon storage efficiency varied with plant species and plant configuration. （2） The soil carbon pool showed a “U” type in the whole period. The average annual growth of soil organic carbon in reclaimed forest land is 0.20-6.27, 0.30-3.37 and 0.31-2.80 Mg·hm-2 in grassland and forest-grass mixture, respectively. （3） Most carbon was stored in vegetation in reclaimed forest, while most carbon was in soil in reclaimed grass land. （4） The soil carbon sequestration efficiency is affected mainly by the physical and chemical properties of soil, up-ground vegetation, reclamation time, site conditions and reclamation technology. Therefore, measures should be ameliorated to speed up the recovery of carbon pool in the mine area. In addition, the optimization of the micro terrain of spoils, selecting of appropriate species and amelioration of vegetation allocation model should also be applied in the process of reclamation. Finally, the emphases for in the carbon pool research in mining area in the future in China was proposed, including strengthening the study of vegetation and soil inorganic carbon pool, the whole life cycle of total carbon pool and the desert opencast coal-mine carbon etc, which may provide a scientific basis for a comprehensive understanding of the dynamic condition of ecosystems carbon in opencast coal-mine.