采动地裂缝作为黄河流域中游煤矿区重要的采动损害类型，影响土壤特性的规律和机理成为当前的研究热点。为了探究采动地裂缝对土壤微生物特性的影响，本试验以陕北煤矿区宽度为20~40 cm的采动地裂缝为研究对象，采集裂缝周围(水平距离60 cm以内、垂直深度60 cm以浅)土壤样品，分别采用绝对定量PCR方法和酶标仪法测定土壤细菌、放线菌、真菌的数量和蔗糖酶、过氧化氢酶、脲酶、磷酸酶的活性，剖析土壤微生物和酶的空间变化特征，在此基础上结合土壤主要理化特性指标，解译采动地裂缝在小空间尺度上对土壤微生物和酶的影响规律。结果表明:① 采动地裂缝对土壤微生物和酶活性的负效应主要表现为水平差异特征，且随着水平距离的增加而明显减弱，当水平距离分别超过75，79，91，72，82，89，96 cm时，采动地裂缝对土壤细菌、放线菌、真菌、磷酸酶、蔗糖酶、过氧化氢酶、脲酶的负影响基本消失，土壤微生物特性的损害主要集中在水平距离1 m以内，可作为陕北煤炭开采损害区土壤微生物精准修复的靶向区域;土壤微生物特性的损害主要集中在水平距离1 m以内，可作为陕北煤炭开采损害区土壤微生物精准修复的靶向区域;② 采动地裂缝周围土壤中有机质、铵态氮、有效磷、有效钾、黏粒、含水率、pH的平均降幅依次为9.51%~28.46%，24.31%~29.31%，12.61%~19.86%，4.11%~6.51%，4.93%~6.46%，2.36%~4.26%，1.98%~3.14%，而土壤有机质、黏粒、铵态氮、有效磷等指标与土壤微生物数量、酶活性在小空间尺度上都存在高度的一致性，相关系数分别超过0.8和0.6，均达到极显著正相关水平(P<0.01)，土壤有机质质量分数也应作为陕北煤矿区采动地裂缝影响土壤微生物和酶活性的重要指示性因素。越靠近采动地裂缝，土壤微生物和养分特性的自我恢复潜力越小，修复时应着重考虑人工方式，反之应着重考虑自然方式。

As an important type of mining damage in the middle reaches of the Yellow River Basin,the law and mechanism of affecting soil characteristics have become a current hot research subject.In order to investigate the effect of mining cracks on soil microbial characteristics,the soil samples around the cracks (within 60 cm of horizontal distance and 60 cm of vertical depth to shallow) were collected from the mining cracks with a width of 20-40 cm in Northern Shaanxi Coal Mine Area in this experiment,and the number of soil bacteria,actinomycetes,and fungi and the activities of sucrase,catalase,urease,and phosphatase were determined by absolute quantitative PCR and microplate reader,respectively,to analyze the spatial change characteristics of soil microorganisms and enzymes.On this basis,the effects of mining cracks on soil microorganisms and enzymes on a small spatial scale were interpreted in combination with the main physicochemical characteristics of the soil.The results showed that:① the negative effect of mining ground cracks on soil microbial and enzyme activities was mainly characterized by horizontal differences,and significantly weakened with the increase of horizontal distance.When the horizontal distance was more than 75,79,91,72,82,89,and 96 cm,the negative effects of mining ground cracks on soil bacteria,actinomycetes,fungi,phosphatases,sucrase,catalase,and urease basically disappeared,and the damage of soil microbial characteristics was mainly concentrated within 1 m of horizontal distance,which could be used as a targeted area for accurate remediation of soil microorganisms in the damaged area of coal mining in northern Shaanxi;② The average decreases of organic matter,ammonium nitrogen,available phosphorus,available potassium,clay,moisture content,pH and the average increase in porosity in the soil around mining ground cracks were 9.51%-28.46%,24.31%-29.31%,12.61%-19.86%,4.11%-6.51%,4.93%-6.46%,2.36%-4.26%,and 1.98%-3.14%,respectively.The correlation coefficients exceeded 0.8 and 0.6,respectively,and reached a highly significant positive correlation level (P

1 研究区概况

2 材料与方法

   2.1 样品采集

   2.2 测定方法

   2.3 数据处理

3 结果与讨论

   3.1 测定结果

   3.2 结果分析

4 讨论

5 结论