黄土旱塬裸地土壤呼吸特征及其影响因子  

Characteristics of soil respiration in fallow and its influencing factors at arid-highland of Loess Plateau

作　　者：高会议[1] 郭胜利[2,3] 刘文兆[2,3] 

机构地区：[1]中国科学院合肥物质科学研究院合肥智能机械研究所,合肥230031 [2]西北农林科技大学水土保持研究所,杨凌712100 [3]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100

出　　处：《生态学报》2011年第18期5217-5224,共8页Acta Ecologica Sinica

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-YW-424-2);国家自然科学基金(40771125,30871451);黄土高原土壤侵蚀与旱地农业国家重点实验室专项经费(10502-Z11)

摘　　要：于中国科学院长武生态试验站(始于1984年),采用动态密闭气室法(Li-8100,USA)于2008年3月至2009年3月监测了裸地土壤呼吸日变化、季节变化以及0—60cm土层的温度和含水量,研究了裸地土壤呼吸的日变化、季节变化特征及其与土壤温度和含水量之间的关系。结果表明:裸地土壤呼吸四季的日变化和季节变化均呈单峰型曲线,与气温变化趋势一致;日变化峰值出现在14:00左右或16:00左右,最低值出现在0:00左右或者6:00左右;季节变化表现为夏季最高,冬季最低,春秋季无明显差异,年平均呼吸速率为0.94"molCO.2m-.2s-1。土壤呼吸与温度具有极显著(P<0.01)的正相关关系,且可以用Rs=aebx形式的指数函数很好地拟合,其中与5cm深度的土壤温度相关性最好。水分对土壤呼吸的影响复杂。裸地土壤呼吸的双变量模型关系显著(P<0.01),比相应的单变量模型更好地解释了土壤呼吸变异。Soil is an important source of atmospheric carbon dioxide （ CO2 ）. It is an important process for soil respiration to release CO2 from biosphere to air, because understanding the rate of soil respiration and temporal and spatial fluctuation under various terrestrial ecosystem can provide the basic data to budget of global carbon balance and to estimate potential effect of global change. Soil respiration was not only influenced by environmental conditions such as temperature, humidity, and pH values, but also was controlled by biotic factors such as vegetation form, leaf area index, living weight and human reactivity. It is noted that soil temperature and moisture content are assumed to two significant environmental factors. Loess plateau located in semiarid districts of northwest of China, where soil exhibited dry and humid change alternately. Studies of CO2 emission from bare soil may help analyze annual changes in carbon （C） in soil organic matter （SOM）. Therefore, CO2 emission associated with the decomposition of SOM from bare soil are important factors for assessing the C budget in agricultural fields. Studies on relationship of soil respiration change and environmental factors （soil temperature and moisture content） presented the important significance to determine the temporal and spatial change of soil respiration in thisbare area. We conducted a study to monitor soil CO2 emission diurnal change, CO2 emission seasonal change, soil moisture, soil temperature, and assess the controlling factors of CO2 emission from an unplanted soil of long-term experiment at Changwu ecological station of Chinese Academy of Science, China. In situ soil CO2 emissions from March 2008 to March 2009were measured with an IRGA CO2 analyzer （Li-COR 8100, Li-COR Corp. , Lincoln, NE） following the dynamic closed chamber method. The CO2 diurnal and seasonal change in the bare soil followed single peak trend, same as the change of soil temperature. The highest value of diurnal change appeared at 14：00 or 16：00,

关 键 词：裸地 土壤呼吸 温度 土壤含水量 

分 类 号：S154[农业科学—土壤学]