煤矿复垦区重构土壤溶解性有机碳空间分布特征

为探究煤矿复垦区重构土壤中溶解性有机碳(DOC)含量的空间分布特征,以淮南潘一矿区煤矸石山和周边复垦区林地土壤为研究对象,从空间分布和颗粒组成上,分析了煤矸石山山顶、山腰和山脚的煤矸石风化物及周边林地土壤中DOC的含量。结果表明:自上而下山顶、山腰、山脚的煤矸石风化物中DOC含量呈递减趋势,并随采样深度的增加而增大;但林地土壤中DOC含量随采样深度的增加而减少。不同粒径颗粒物中DOC含量分布不同,煤矸石风化物和林地土壤均以细砂(0.2~0.05 mm)DOC含量最高,石砾(10~2 mm)DOC含量最低。在雨水淋溶作用下,煤矸石风化物对周边土壤DOC含量贡献较大,距离山脚1~100 m范围,随着距离的增加,土壤中DOC含量由325.46 mg/kg减少至177.89 mg/kg,煤矸石风化物对周边土壤DOC含量的贡献率由85.78%降低到1.54%,在距离山脚100 m处土壤中DOC含量已接近正常对照土壤含量。

Spatial Distribution Characteristics of Dissolved Organic Carbon in Reconstructed Soil in Coal Mine Reclamation Area

In order to analyze the spatial distribution characteristics of dissolved organic carbon(DOC) in reconstructed soil in coal mine reclamation area, this study selected a coal gangue pile and peripheral reclaimed forestry soil in Panyi Coal Mine in Huainan as the study object, the contents of DOC in gangue weathering matters located at the peak, slope and foot of the gangue pile and in reclaimed forestry soil and in their different size particles were measured. The results showed that DOC contents in gangue weathering matters decreased from the peak to foot of gangue pile but increased with the increase of profile depth at the same site, while DOC content in forestry soil reduced with the increase of profile depth. DOC contents were different in different size particles, fine sand part (0.2-0.05mm) had the highest DOC content while gravel part (10-2mm) had the smallest DOC content. Under the leaching of rainwater, gangue weathering matter contributed significantly to DOC content in peripheral soil, within the range of 1-100m, with the increase of the distance from the foot of gangue pile, DOC content in soil decreased from 325.46 mg/kg to 177.89 mg/kg, the contribution rate of gangue weathering matter to soil DOC content decreased from 85.78% to 1.54%, and DOC content in soil at 100 m far was near the normal level of CK soil.