采煤沉陷区裂缝边缘带土壤、作物、微生物响应

[目的]研究采煤沉陷区裂缝边缘带土壤、作物、微生物变化特征,为开展沉陷区生态减损与自修复提供理论依据。[方法]以神东矿采煤沉陷区作为研究对象,采用野外监测结合室内分析从裂缝产生初始阶段(LFC)至裂缝发育相对稳定阶段(LFW)15 d内,裂缝边缘带土壤、作物、微生物响应特征。[结果]裂缝边缘带表层10 cm深度范围内土壤含水率在裂缝产生3 d后损失殆尽且后期无法恢复,20 cm以下深度的土壤含水率虽受影响,但并不显著。沉陷区裂缝对土壤理化指标及酶活性产生了扰动影响,但并不显著。沉陷区裂缝发育对边缘带土壤微生物造成了扰动影响,使得土壤微生物群落均匀度、相对丰度降低,细菌相对丰度大于1%的优势菌门少了装甲菌门(Armatimonadetes)、和厚壁菌门(Firmicutes); 真菌相对丰度大于1%的优势菌门少了芽枝霉门(Blastocladiomycota)。RDA分析表明,土壤T,OM,AK,AP,pH,AN是驱动土壤微生物群落结构变化的核心因子。Pearson相关性分析表明裂缝边缘带作物遭受土壤水分和温度胁迫显著,体内可溶性糖SS、超氧化物歧化酶SOD、可溶性蛋白SP、丙二醛MAD含量上升,且受胁迫程度为:玉米>卷心菜>土豆。[结论]沉陷区裂缝发育是推动裂缝边缘带土壤环境因子、微生物群落及作物产生联动响应的源动力。

Response Characteristics of Soil,Crops and Microorganisms at the Fracture Edge of the Coal mining Subsidence Area

[Objective]The response characteristics of soil, crops and microorganisms at the fracture zone of the subsidence area was studied in order to provide a theoretical basis for ecological damage reduction and self-repair in the subsidence area. [Methods] The coal mining subsidence area of Shendong was taken as the research site, the response characteristics of soil, crops and microorganisms at the fracture edge of the subsidence area within 15 days from LFC to LFW were studied by using field monitoring and indoor analysis.[Results] The surface soil moisture content within the depth of 10 cm was completely lost and could not be recovered after 3 days of subsidence and fracture generation, soil moisture was also affected within the depth of 20 cm, but not significantly. The development of fracture in the subsidence area had a disturbing effect on soil physicochemial indexes and enzyme activities, but it was not significant. The development of fracture in the subsidence area caused disturbance to soil microorganisms, which reduced the uniformity and relative abundance of soil microbial communities,the dominant phyla of bacteria with a relative abundance greater than 1% were lacked of Armatimonadetes and Firmicutes,the dominant phyla of fungi with a relative abundance greater than 1% was lacked of Blastocladiomycota. RDA analysis showed that soil T, OM, AK, AP, pH, and AN were the critical factors driving the changes of soil microbial community structure. Pearson correlation analysis showed that the crops at the fracture edge of the subsidence area were significantly stressed by soil water and temperature, and the contents of SS, SOD, SP and MAD in the crops increased significantly, and the stress degree was corn>cabbage>potato. [Conclusion] Fracture development in the area of the subsidence is the source driver of the linkage response of soil environmental factors, microbial communities and crops in the fracture margin zone.