煤矿废弃地生态修复的土壤有机碳效应

采煤使得植被和土壤遭到损毁破坏,导致原生态系统碳汇功能的急剧退化甚至完全丧失。采煤堆积的煤矸石可发生氧化自燃,是巨大的CO_2排放源。生态修复对减少矿区碳排放及减缓大气温室效应具有重要意义。分析了国内外煤矿废弃地生态修复后的土壤有机碳动态特征,修复模式、修复时间和修复措施对土壤有机碳及其活性组分的影响,总结了土壤固碳的主要影响因子。研究结果表明,土壤有机碳在人工植被修复和有机物添加后增加显著,且与修复时间成正比。煤矿废弃地通过采取适宜的生态修复措施,有很大的土壤固碳潜力。未来应加强团聚体固碳等土壤固碳机理和土壤活性有机碳等科学问题的研究,以期为退化区生态修复进程中土壤固碳功能提升提供参考。

Effects of ecological restoration on soil organic carbon in post-mining lands

Coal mining has caused severe damage to vegetation and soil, leading to a sharp degradation or entire loss of the carbon sequestration function of the original ecosystems. Furthermore, accumulated coal-gangues are easily oxidized or combusted, which has resulted in huge emissions of CO₂. Ecological restoration in post-mining areas is of great significance to curb regional carbon emission, and to mitigate greenhouse effects. In this study, the effects of ecological restoration on changes in soil organic carbon were reviewed, including the effects of restoration type and time; restoration measures for soil organic carbon and its active fractions, and the main factors influencing carbon sequestration were also summarized. The results showed that soil organic carbon increased significantly through vegetation restoration and organic matter addition and was positively correlated with restoration time. The results suggested that degraded lands in post-mining areas have great potential for carbon sequestration by adopting suitable restoration measures. In the future, research on the mechanism of carbon sequestration in soil aggregates and the active fractions of soil carbon should be prioritized because such studies could provide references for the enhancement of carbon sequestration function in degraded areas during restoration processes.