放牧对荒漠草原土壤养分及微生物量的影响  

Effects of Grazing on Soil Nutrients and Microbial Biomass in Desert Steppe

作　　者：孙海燕[1] 万书波[2] 李林[1] 刘登望[1] 

机构地区：[1]湖南农业大学生物科学技术学院,湖南长沙410128 [2]山东省农业科学院,山东济南250100

出　　处：《水土保持通报》2015年第2期82-88,93,共8页Bulletin of Soil and Water Conservation

基　　金：湖南省研究生科研创新基金项目"基于循环经济的花生产业发展研究"(CX2012B310)

摘　　要：[目的]探讨不同放牧强度对荒漠草原植被多样性、土壤理化性状、土壤养分及土壤微生物量的影响。[方法]以围封禁牧草地为对照,采用野外调查和室内分析的方法,对不同放牧强度下的草地土壤及植被展开调查。[结果]随放牧强度的增加,荒漠草原植被盖度、物种多样性、地上生物量、土壤养分和微生物量显著降低,土壤容重和pH值呈增加趋势,土壤电导率呈先增加后降低趋势,地下生物量则没有明显变化趋势;在植被作用下土壤养分和微生物量垂直方向表现递减规律并且在表层富集,"表聚性"较为明显;在放牧干扰下土壤全磷变异系数最高;放牧并没有改变荒漠草原土壤养分和微生物量的垂直分布特征;相关分析表明,放牧干扰下土壤微生物量与土壤养分之间具有较强的相关性,二者与土壤含水量也有较强的相关性。[结论]放牧强度对土壤全磷的空间变异影响较大,并且土壤微生物量对于放牧干扰的敏感性高于土壤养分全量;土壤养分和微生物量等地下生态系统各指标之间具有统一性。[Objective]This study aimed to explore the effects of grazing disturbance on soil nutrients and microbial biomass in desert steppe.[Methods]The impacts of grazing disturbance（high disturbance,HD;middle disturbance,MD;lower disturbance,LD）on soil nutrients and microbial biomass was analyzed based on the field investigation and the laboratory analysis.[Results]The vegetation coverage,species diversity,ground biomass,soil nutrients and microbial biomass significantly reduced.The soil bulk density and pH value increased.The soil conductivity firstly increased and then decreased with the increase of grazing intensity,while the underground biomass had no obvious trend.The soil nutrient and microbial biomass decreased progressively with the increase of soil depth and showed enrichment in the surface soil layer,the＂surface accumulation＂was observed obvious.The variation coefficient of soil total phosphorus was the highest,which implied that the spatial variability of soil total phosphorus was mostly influenced by grazing intensity.The vertical distributions of soil nutrients and microbial biomass were not affected by razing or not,and were independent on the grazing intensity.Microbial biomass had significant correlation with soil nutrients though grazing disturbed.The two items also had obvious correlations with soil moisture.[Conclusion]Soil total phosphorus showed more spatial heterogeneous than other nutrients under grazing conditions.And soil microbial biomass was more sensitive than soil nutrients to grazing disturbance.The variation responses of soil nutrients,microbial biomass and other indicators to grazing showed a consistency trait.

关 键 词：荒漠草原 放牧干扰 土壤养分 土壤微生物量 

分 类 号：S158.3[农业科学—土壤学]