黄土高原矿区土壤细菌群落对地表塌陷和土地复垦的响应

Response of coal mining bacterial community to surface subsidence and land reclamation in the Loess Plateau

中国一半的煤炭生产能力集中于生态脆弱的黄土高原,采矿活动进一步加剧了当地生态环境恶化,尤其是土壤退化.微生物是土壤物质转化的动力,对外界干扰十分敏感,厘清其变化对生态恢复和治理尤为重要.为此,本研究以黄土高原大柳塔煤矿及黑岱沟煤矿为对象,利用高通量测序技术和分子生态网络分析方法,揭示土壤细菌群落多样性及不同活动影响下土壤细菌群落之间的联系与差异.结果表明,不同活动对土壤理化性状影响显著,塌陷区有机质、速效磷、速效钾呈显著性下降(P<0.05),复垦区土壤有机质、水分、pH和电导率则显著增加(P<0.05),塌陷对土壤理化性状产生了抑制作用,复垦呈现促进作用.不同活动对土壤细菌群落产生不同的影响,塌陷区多样性指数降低了约20%,复垦则多样性指数增加了63%,但塌陷区、复垦区优势菌门保持一致.不同活动对土壤细菌分子生态网络的影响迥异:塌陷后分子生态网络趋于复杂,网络连接数及互作关系明显增强;复垦后则生态网络模块增加,模块内部趋于简单.为应对地表塌陷和土地复垦,土壤细菌往往改变菌种间关系作适应性变化.塌陷更多地促进相互合作以适应养分的贫瘠,复垦则促进模块数增加并趋于合作以获取更多的资源.

A half of China′s coal production capacity is located in the Loess Plateau,which has a fragile ecological environment.Mining activities further seriously interfered the local ecosystem,especially soil degradation.Microorganism could work as the driver for soil material transformation,and they are very sensitive to external disturbance.It is significantly important to clarify their variations for ecological restoration.Therefore,in this study,under different coal mining disturbances,soil bacterial diversities,and the relationships among themselves were explored through the high-throughput sequencing technique and the molecular ecological network analysis,with Daliuta and Heidaigou coal mines as the research object.The results showed as follows:Coal mining disturbances had seriously affected the soil physicochemical properties.The organic matter,available phosphorus and available potassium in the subsidence area significantly decreased(P<0.05),while the soil moisture,pH,EC and organic matter in the land reclamation area significantly increased(P<0.05).Coal mining subsidence inhibited several soil properties,whereas land reclamation could stimulate some different soil properties.Coal mining disturbances showed different impacts on diversity index of soil bacterial communities.The index of subsided mining area decreased about 20%,while it increased 1.63 times in reclamation area.However,the dominant bacteria in both regions were consistent.The two disturbances significantly affected soil microbial molecular ecological networks.After subsidence,the molecular ecological network tended to be complex,and the number of network connections and interactions significantly enhanced.On the other side,the network module increased and the interior of the module tended to be simple after land reclamation.To cope with the disturbances of different ways,soil bacteria might change their interspecies relationships to make more adaptive changes.Subsided disturbance promoted greater cooperation to adapt to the nutrient depletion,while land reclamation increased the module numbers for cooperation to obtain more resources.