模拟氮沉降和降水增加对弃耕草地土壤微生物学特性的影响  

Effects of N Addition and Increased Precipitation on Soil Microbial Characteristics in Abandoned Grasslands

作　　者：张玉革[1] 刘月秀 杨山 马锐骜[2] 吴辉 孟亚妮 李慧 ZHANG Yuge;LIU Yuexiu;YANG Shan;MA Ruiao;WU Hui;MENG Yani;LI Hui(College of Environment, Shenyang University, Shenyang 110044, China;Erguna Forest-Steepe Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China)

机构地区：[1]沈阳大学环境学院,辽宁沈阳110044 [2]中国科学院沈阳应用生态研究所额尔古纳森林草原过渡带生态系统研究站,辽宁沈阳110016

出　　处：《沈阳大学学报（自然科学版）》2021年第1期10-19,共10页Journal of Shenyang University：Natural Science

基　　金：国家重点研发项目(2016YFC0500601,2016YFC0500707).

摘　　要：研究了模拟氮沉降和降水增加对弃耕恢复草地土壤理化性质、微生物生物量、酶活性和酶化学计量学参数的影响.结果表明,氮添加显著降低了土壤pH值,对土壤全碳、全氮、铵态氮、硝态氮和地上植被净初级生产力无显著影响.氮添加显著降低了土壤微生物生物量,增加了土壤微生物生物量碳氮比,表现出微生物适应外界环境变化的一种自身调控机制.氮添加降低了氮获取酶活性,增加了碳获取酶活性,符合资源分配假说.降水增加显著增加了土壤微生物生物量,缓解了土壤酸化对土壤微生物生长的负效应.此外,大分子底物(例如纤维素和蛋白质)水解酶活性及其计量比更能反映微生物养分需求.The effects of simulated nitrogen subsidon and precipitation increase on the physical and chemical properties,microbial biomass,enzyme activity and enzyme chemistry metrological parameters of abandoned grasslands were studied.The results showed that nitrogen addition significantly reduced soil pH and had no significant effect on soil total carbon,total nitrogen,ammonium nitrogen,nitrous nitrogen and net primary productivity of above-ground vegetation.Nitrogen addition significantly reduced soil microbial biomass,increased soil microbial biomass carbon-nitrogen ratio,showing that microorganisms adapt to changes in the external environment of a self-regulation mechanism.Nitrogen addition reduces nitrogen acquisition enzyme activity,increases carbon acquisition enzyme activity,and conforms to the resource allocation hypothesis.The increase of precipitation significantly increases the biomass of soil microorganisms and alleviates the negative effect of soil acidification on soil microbial growth.In addition,the hydrolyzed enzyme activity of large molecular substrates(e.g.cellulose and protein)and its measurement ratio are more reflective of microbial nutrient needs.

关 键 词：弃耕草地 氮添加 降水增加 微生物生物量 土壤酶活性 

分 类 号：S154.1[农业科学—土壤学]