温度和水分对干热河谷耕地和草地土壤微生物的影响  

Effects of temperature and moisture treatments on microbial characteristics of arable and grassland soil in dry-hot valley

作　　者：彭思利 武仁杰 张鑫 葛之葳 杨楠 PENG Sili;WU Renjie;ZHANG Xin;GE Zhiwei;YANG Nan(Co-Innovation Center for Sustainable Forestry in Southern China/College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037,Jiangsu,China)

机构地区：[1]南京林业大学南方现代林业协同创新中心/南京林业大学生物与环境学院,江苏南京210037

出　　处：《草业科学》2021年第12期2350-2362,共13页Pratacultural Science

基　　金：十三五重点研发计划(2016YFC0502605);国家自然科学基金项目(41601254);江苏省高校优势学科建设工程项目(PAPD)。

摘　　要：为了探究温度和水分对干热河谷区不同土地利用类型土壤微生物特征的影响,本研究以元谋干热河谷耕地和草地土壤的微生物为对象,设置3种温度(15、25和35℃)和3种水分[80%、60%和40%最大田间持水量(WHC),即80%WHC、60%WHC和40%WHC]处理的室内土壤培养试验,分别测定了培养7、14和28 d的土壤微生物呼吸速率、累积呼吸量和微生物代谢熵(qCO_(2))和培养28 d后细菌群落结构特征。结果表明:在各个培养时期,草地土壤微生物呼吸速率、累积呼吸量和细菌群落多样性(Shannon指数)均显著高于耕地土壤(P<0.05),而草地土壤qCO_(2)显著低于耕地土壤(P<0.05)。随着培养温度升高,微生物呼吸速率和累积呼吸量均显著增加,培养14 d后的Q_(10)值明显高于7 d和28 d(P<0.05);但水分处理对不同土壤类型微生物呼吸影响方式不同,60%WHC水分条件下两种土壤微生物累积呼吸量均有增加的趋势。ANOSIM相似性检验结果显示,土壤类型显著影响土壤细菌群落结构组成(r=0.715,P<0.01);相对于耕地土壤,温度和水分处理对草地土壤细菌群落结构组成的影响更大,且两种土壤中优势类群相对丰度随温度和水分变化方式具有明显差异。In order to investigate the influences of temperature and moisture on soil microbial characteristics under different land use types,a laboratory incubation experiment using arable and grassland soils collected from Yuanmou dry-hot valley with a full factorial combination of three temperature levels(15℃,25℃and 35℃)and three moisture levels(40%,60%and 80%water holding capacity-WHC)was conducted.Soil microbial respiration rate,cumulative respiration and microbial metabolic quotient(qCO_(2))after 7 d,14 d and 28 d’s incubations,and soil bacterial community composition after 28 d’s incubation were measured.At each stage of the incubation,microbial respiration rate,cumulative respiration and soil bacterial community diversity(Shannon index)in grassland soil were significantly higher than those in arable soil,while microbial metabolic quotient in grassland soil was significantly lower than that in arable soil(P<0.05).Soil respiration rate and cumulative respiration in both soils increased significantly with the temperature.The Q_(10) value at the middle stage of the incubation(14 d)was significantly higher than that at the early(7 d)and late(28 d)stages(P<0.05).The water treatment had different effects on microbial respirations for different soils,and the cumulative respiration under 60%WHC was larger than those under the other two water treatments.ANOSIM similarity tests suggested that land-use type had a great effect on soil bacterial community composition(r=0.715,P<0.01).Compared to arable soil,the bacterial community structure in grassland soil was more sensitive to the temperature and moisture treatments.The relative abundances of dominant groups in grassland and arable soils varied differently with the temperature and water levels.

关 键 词：培养试验 培养时期 微生物呼吸 累积呼吸量 微生物代谢熵 细菌群落结构 细菌群落多样性 

分 类 号：S812.2[农业科学—草业科学] S154.3[农业科学—畜牧学]