干热河谷梯级库区土壤微生物群落特征及其影响因素研究  

Characterization of Soil Microbial Communities and Their Influencing Factors in Hot-dry Valleys with Cascade Reservoirs

作　　者：孙干 孙然好[2] 徐火清 孙龙[2] 董一帆 孙涛[2] 陈利顶[2] SUN Gan;SUN Ran-hao;XU Huo-qing;SUN Long;DONG Yi-fan;SUN Tao;CHEN Li-ding(China Three Gorges Construction Engineering Corporation,Chengdu 610041,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Yunnan University,Kunming 650091,China)

机构地区：[1]中国三峡建工(集团)有限公司,四川成都610041 [2]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [3]云南大学,云南昆明650091

出　　处：《长江流域资源与环境》2023年第3期507-515,共9页Resources and Environment in the Yangtze Basin

基　　金：国家自然科学基金联合基金项目(U2102209);中国三峡建工(集团)有限公司技术服务项目(JG/18103B,JG/18104B,JG/18105B,JG/18106B)。

摘　　要：水电开发蓄水能够影响周边气候、植被甚至土壤养分循环,土壤微生物是环境变化的敏感土壤因子,其对梯级水电开发的响应并不明确。在4、9月采集金沙江下游向家坝、溪洛渡、白鹤滩、乌东德4个梯级库区土壤样品,通过磷脂脂肪酸(PLFA)法量化了干热河谷梯级库区4、9月土壤微生物PLFA总量及群落结构,分析了梯级库区土壤微生物变化的主导因素,明确了水电开发截流、蓄水对土壤微生物的影响。结果表明:(1)气象因子、土壤养分能够解释大部分土壤微生物的变异,干热特征更明显的白鹤滩、乌东德库区(84.1%、93.5%)解释度高于向家坝、溪洛渡库区(41.1%、77.0%);(2)土壤微生物在4月主要与全氮、有效氮、降水呈正相关,与温度、潜在蒸散发呈负相关。土壤微生物在9月主要与降水、有机质、有效氮呈正相关,与潜在蒸散发呈负相关;(3)在4、9月蓄水对土壤微生物变异的单独贡献度分别为2.2%、6.8%,与其它因子协同解释度不超过22.4%。而在白鹤滩、乌东德库区,在4、9月蓄水(截流)对土壤微生物变异的单独贡献度分别为5.5%、8.3%,与其它因子的协同贡献度均为13%。总体上,金沙江下游干热河谷梯级水电开发引起的河道截流、水库蓄水会影响土壤微生物PLFA及其群落结构,但其影响容易被气候变化和土壤养分所掩盖。梯级水电站蓄水可能在一定程度上缓和典型干热河谷气候对土壤微生物的不利影响、提高土壤微生物群落结构稳定性。本研究有助于深入认识土壤微生物对水电开发的响应,对于科学评估水电开发的陆生生态系统影响及土壤资源可持续性具有重要意义。Reservoir impoundment affects local climate.The soil microbes are a sensitive indicator for environmental changes and their response to dam development is rarely investigated.This study investigated the soil microbial in April and September in four reservoir zone:Xiluodu,Xiangjiaba,Baihetan,and Wudongde in the lower Jinsha River.The total PLFA content and soil microbial community in April and September in the reservoir areas of the dry-hot valleys were determined by the phospholipid fatty acid(PLFA)method.This study analyzed the dominant factors of soil microbial variations and quantified the effects of river interception and reservoir impoundment on the soil microbial community.The results showed that:(1)meteorological factors and soil nutrients could explain most of the variation of soil microbes,with the degree of explanation of Baihetan and Wudongde reservoirs(84.1%,93.5%)larger than Xiangjiaba and Xiluodu reservoirs(41.1%,77.0%).(2)soil microbes positively correlated with total nitrogen,available nitrogen,and precipitation in April,and negatively correlated with temperature and potential evapotranspiration.In September,soil microbes positively correlated with precipitation,organic matter,and available nitrogen,and negatively correlated with potential evapotranspiration.(3)the individual contribution of water impoundment to soil microbial variation in April and September was 2.2% and 6.8%,respectively,and the variation explained by both impoundment and other factors less than 22.4%.In contrast,in the Baihetan and Wudongde reservoirs,the individual contribution of the impoundment to soil microbial variation in April and September was 5.5% and 8.3%,respectively,and the joint contribution with other factors was 13% in both cases.Overall,impoundment caused by the hydropower development in the lower Jinsha River in hot-dry valleys affects soil microbial PLFA content and their community structure,but their effects are easily masked by climate change and soil properties.The impoundment in the cascade reservoirs,to s

关 键 词：土壤微生物 土壤养分 水电蓄水 磷脂脂肪酸 金沙江下游 

分 类 号：S154[农业科学—土壤学] X14[农业科学—农业基础科学]