荒漠区不同大小灌丛周围土壤微生物生物量及活性特征  

Soil microbial biomass and activity under desert shrub canopies

作　　者：陈鸿洋[1] 尚振艳[1] 傅华[1] 张宝林 张斯莲 牛得草[1] 

机构地区：[1]草地农业生态系统国家重点实验室、兰州大学草地农业科技学院,甘肃兰州730020 [2]内蒙古阿拉善盟草原总站,内蒙古巴彦浩特750306 [3]内蒙古阿拉善盟气象局,内蒙古巴彦浩特750306

出　　处：《草业学报》2015年第2期70-76,共7页Acta Prataculturae Sinica

基　　金：长江学者和创新团队发展计划(IRT13019);中国科学院战略性先导科技专项(XDA05050406-8);国家科技基础性工作专项(2012FY111900);国家自然科学基金(31070412);高等学校博士学科点专项科研基金(20120211110029)资助

摘　　要：为了解不同大小灌丛对荒漠区土壤生物学性状的影响与作用,本研究在东阿拉善荒漠区选择两组不同大小的红砂灌丛,研究其周围土壤资源的空间异质性和土壤微生物特性的变化规律。结果表明,红砂灌丛下沙堆土壤有机碳和全氮含量显著大于其内部和外部土壤,随灌丛增大,沙堆有机碳和全氮含量无显著变化,而土壤水分含量显著增加;另外,灌丛周围土壤微生物生物量碳氮含量较低,分别为55.23~113.81mg/kg和5.46~7.66mg/kg,其中,灌丛内部土壤微生物生物量碳含量和微生物熵（qMB）显著高于灌丛外部与沙堆,而土壤微生物呼吸熵（qCO2）变化与之相反;随灌丛增大,内部土壤微生物生物量与微生物活性保持稳定,变化较小。以上结果说明红砂灌丛对风蚀拦截形成的沙堆富含大量养分,但沙堆养分含量与灌丛大小无关,同时沙堆的形成对维持灌丛内部土壤微环境的稳定与健康具有重要作用。The effects of different size shrub （two groups of Reaurnuria soongorica shrubs） on the spatiotempo- ral heterogeneity of soil properties were studied in the eastern Alxa Plateau. The soil organic carbon （SOC） and total nitrogen （TN） were significantly higher in the nebkha （dune） beneath and at the perimeter of shrub cano- pies. No differences were observed for SOC and TN in nebkhas under shrubs of different size. However, soil water content of nebkhas increased markedly with increasing shrub size. Soil microbial biomass carbon （MBC） and microbial biomass nitrogen （MBN） were 55.23-113.81 mg/kg and 5.46-7.66 mg/kg, respectively. The soil MBC and microbial quotient （qMB） were significantly higher beneath the shrub canopies than at the perim- eter. The soil microbial biomass and activity beneath the shrub canopy remained relatively stable. The nebkha under the shrub canopies contained more nutrients but was not affected by shrub size. The formation of nebkhaplayed an important role in maintaining the stability and health of the soil microenvironment beneath shrub canopies.

关 键 词：土壤微生物量 土壤微生物活性 灌丛大小 荒漠 

分 类 号：S154.3[农业科学—土壤学]