模拟增温增雨对克氏针茅草原土壤呼吸的影响  

Effects of Simulated Warming and Precipitation Enhancement on Soil Respiration of Stipa krylovii Steppe

作　　者：张立欣[1,2] 杨劼[1] 高清竹[2] 苏力德[1] 干珠扎布[2] 侯虹[1] 

机构地区：[1]内蒙古大学生命科学学院,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/农业部农业环境重点试验室,北京100081

出　　处：《中国农业气象》2013年第6期629-635,共7页Chinese Journal of Agrometeorology

基　　金：国家科技支撑计划项目(2013BAC09B03;2011BAC07B00);农业部项目"国家牧草现代产业技术体系"(CARS-35)

摘　　要：利用开顶式生长室(OTC)于2011年7-9月和2012年5-9月两个植物生长季在以克氏针茅(Stipa krylovii)为主要建群种的典型草原进行模拟增温和增雨的控制试验,以探讨增温和增雨及其交互作用对内蒙古克氏针茅(S.krylovii)草原土壤呼吸的影响。结果表明:(1)土壤呼吸速率日内变化和逐日变化均呈单峰曲线趋势,全天15:00达到最高值(2.26μmol·m-2·s-1),生长季8月初达到最高值(5.51μmol·m-2·s-1)。9:00-11:00土壤呼吸速率能较好代表全天24h均值。(2)与对照相比,增温1.91℃使土壤呼吸速率降低19.0%,且白天降幅大于夜间。增雨20%使土壤呼吸速率较对照增加18.6%。而增温增雨(气温增加1.64℃,降雨量增加20%)处理下,土壤呼吸速率较对照增加13.0%。(3)土壤呼吸速率与土壤含水量、土壤温度均具有显著相关关系。约79%的土壤呼吸速率是由土壤温度和土壤含水量共同决定的,其中以土壤含水量为主(R2=0.797,P<0.001)。气温升高使土壤含水量降低,间接导致土壤呼吸速率下降。研究结果可为典型草原科学应对气候变化和草地畜牧业可持续发展提供依据。In this study, authors conducted experiments for two growing seasons （2011 and 2012）in Stipa krylovii Steppe, Inner Mongolia, China. Using open top chambers（OTCs） to simulate warming and precipitation enhancement. To study the effects of climate warming and increasing precipitation and the interaction on soil respiration of S. krylovii Steppe. The results showed that ： （ 1 ） both the diurnal change and daily variation pattern of soil respiration rate had a single peak,the highest respiration rate appeared in the 15：00pm in diurnal（2.26μmol · m-2 · s-1） and late August in the growing season （ 5.51 μmol · m-2 · s-1 ）. Soil respiration rate of 9：00 - 11：00 can better represent the mean of all day. （2）Compared with the control, soil respiration rate reduced 19. 0% when the air temperature increasing 1.91 ℃, but increased 18.6% under precipitation enhancement treatment （increase precipitation 20%）. Warming and precipitation enhancement treatment （ increase air temperature 1.64℃, and increase precipitation 20% ） increased 13.0% soil respiration rate compared with the control. （3）There were significant relationship among soil moisture ,soil temperature and soil respiration rate. About 79% of soil respiration change was determined by the soil temperature and soil moisture, but the mainly influencing factor was soil moisture content（ R2 = 0. 797, P 〈 0. 001 ）. Warming resulted in reduced soil moisture, indirectly led to the soil respiration rate decline. The results can provide the basis for the sustainable development of the science of climate change and the typical steppe grassland animal husbandry.

关 键 词：全球变化 土壤呼吸 典型草原 模拟增温与增雨 

分 类 号：S812.2[农业科学—草业科学]