水热因子对克氏针茅草原土壤呼吸及其土壤温度敏感性的影响  

The influence of hydrothermal factors on soil respiration and soil temperature sensitivity of Stipa krylovii steppe,Inner Mongolia,China

作　　者：谷蕊[1,2] 潮洛濛[1] 张立欣[1,2] 苏力德[1,2] 万志强[1,2] 闫玉龙[1,2] 陈雅丽[1,2] 高清竹[2] 

机构地区：[1]内蒙古大学生命科学学院,内蒙古呼和浩特010021 [2]中国农业科学院农业环境与可持续发展研究所农业部农业环境与气候变化重点试验室,北京100081

出　　处：《草业学报》2015年第4期21-29,共9页Acta Prataculturae Sinica

基　　金：国家科技支撑计划项目(2013BAC09B03);农业部项目"国家牧草现代产业技术体系"(CARS-35)资助

摘　　要：作为内蒙古重要的草地资源,克氏针茅草原在我国畜牧业生产中占有重要的地位。土壤呼吸是大气与陆地生态系统碳循环的主要通量,是土壤碳输出的主要途径。试验区设置在内蒙古锡林浩特市东部毛登牧场内以克氏针茅建群的典型草原;在2011-2013年采用开顶式生长室(OTC)对试验样地进行模拟增温增雨处理,在生长季(5-9月份)使用开路式土壤碳通量测量系统(LI-8100,LI-COR,NE)对试验样地土壤呼吸强度进行测定;同时监测试验样地气温、土壤温湿度等环境因子,采集土壤样品并室内分析土壤养分特征和微生物生物量,并对土壤呼吸与环境因子间进行相关性分析。克氏针茅草原土壤呼吸受空气温度和土壤含水量影响显著(P<0.05),分别呈现出二项函数和线性相关关系;不同处理下土壤呼吸在相同时间存在显著差异(P<0.05),2012年增温增雨与增温处理下土壤呼吸速率分别为2.60和1.96μmol/(m2·s),2013年增温增雨与增温处理下土壤呼吸速率分别为3.38和2.09μmol/(m2·s);增温增雨处理下,克氏针茅草原空气温度的升高和土壤含水量的降低均对土壤呼吸产生了抑制。土壤呼吸温度敏感度(Q10)在2011-2012年中增温增雨处理明显高于对照处理和控温处理;2011-2013年控温处理都低于对照处理。本研究表明,土壤呼吸主要受水热条件影响,并且空气温度升高和土壤含水量的降低均对土壤呼吸有抑制作用,增温增雨处理下土壤呼吸速率要高于增温处理;土壤呼吸温度敏感系数与土壤温度、土壤含水量、土壤有机碳、全氮和微生物等环境因子之间的关系较为复杂,还有待深入研究。The grasslands of the Inner Mongolian Stipa krylovii steppe make an important contribution to ani-mal production in China.Soil respiration is an important component of the carbon cycle on the steppe and the main source of soil carbon losses.In this study,typical grassland dominated by S .krylovii,located in Mao-deng Ranch,Xilinhaote,Inner Mongolia was selected as the study area.An open top type growth chamber was used to simulate the response of soil respiration to temperature and precipitation from 2011 to 2013.The Auto-mated Soil CO2 Flux System （LI-8100,LI-COR,NE）was used to observe the soil respiration in the study area during the growing season （May to September）.Air temperature,soil temperature and soil moisture were measured using the EM50 Data Collection System （Decagon Devices,Inc.,NE,USA）.Soil samples were col-lected,soil nutrients and microbial numbers were determined and correlation analysis used to explore associa-tions between soil respiration rate and environmental factors.Soil respiration was significantly affected by air temperature and soil water content （P 〈0.01）.Under warm and warm-moist conditions respectively soil respi-ration rates were 2.60 μmol/（m2 ·s）and 1.96 μmol/（m2 ·s）（2012）and 3.38 μmol/（m2 ·s）and 2.09 μmol/（m2 ·s）（2013 ）;differences between years were significant （P 〈0.05 ）.Increased air temperature and de-creased soil water content both inhibited soil respiration.During the 2013 growing season additional environ-mental factors including soil organic carbon,total nitrogen and soil microbial mass may also have affected soil respiration.The Q10 temperature coefficient was significantly increased by warm-moist conditions.It was con-cluded that soil respiration is mainly influenced by hydrothermal conditions;increased air temperature and re-duced soil moisture content inhibit soil respiration.The relationship between environment factors and soil res-piration on the Inner Mongolian steppe is complex and requires further research.

关 键 词：克氏针茅草原 土壤呼吸 温度 土壤理化性质 土壤微生物 

分 类 号：S812.2[农业科学—草业科学]