神农架海拔梯度上4种典型森林的土壤呼吸组分及其对温度的敏感性  

Components of soil respiration and its temperature sensitivity in four types of forests along an elevational gradient in Shennongjia,China

作　　者：罗璐[1,2,3] 申国珍[1,3] 谢宗强[1,3] 周利光[4] 

机构地区：[1]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093 [2]中国科学院研究生院,北京100049 [3]湖北神农架森林生态系统国家野外科学观测研究站,湖北兴山443700 [4]内蒙古大学生命科学学院,呼和浩特010021

出　　处：《植物生态学报》2011年第7期722-730,共9页Chinese Journal of Plant Ecology

基　　金：植被与环境变化国家重点实验室项目"成熟林的重要功能过程对环境变化响应联网研究";国家自然科学基金(30870416);中国科学院战略性先导科技专项(XDA050203)共同资助

摘　　要：量化森林土壤呼吸及其组分对温度的响应对准确评估未来气候变化背景下陆地生态系统的碳平衡极其重要。该文通过对神农架海拔梯度上常绿阔叶林、常绿落叶阔叶混交林、落叶阔叶林以及亚高山针叶林4种典型森林土壤呼吸的研究发现:4种森林类型的年平均土壤呼吸速率和年平均异养呼吸速率分别为1.63、1.79、1.74、1.35μmolCO2·m-2·s-1和1.13、1.12、1.12、0.80μmolCO2·m-2·s-1。该地区的土壤呼吸及其组分呈现出明显的季节动态,夏季最高,冬季最低。4种森林类型中,阔叶林的土壤呼吸显著高于针叶林,但阔叶林之间的土壤呼吸差异不显著。土壤温度是影响土壤呼吸及其组分的主要因素,二者呈显著的指数关系;土壤含水量与土壤呼吸之间没有显著的相关关系。4种典型森林土壤呼吸的Q10值分别为2.38、2.68、2.99和4.24,随海拔的升高土壤呼吸对温度的敏感性增强,Q10值随海拔的升高而增加。Aims Quantifying forest soil respiration（Rs）,its components of heterotrophic respiration（RH） and autotrophic respiration（RA）,and their responses to temperature are vital to accurately evaluate response of the terrestrial car-bon balance to future climate change.Our specific objectives were to（1） compare patterns of soil respiration of four types of forests,（2） evaluate relationships among soil respiration and temperature and water content and（3） find the regulation of Q10 value in relation to elevation.Methods Four types of forests along an elevational gradient at Shennongjia were investigated.The trenching plot approach was used to partition soil respiration into autotrophic respiration and heterotrophic respiration.Rates of soil respiration were measured twice a month from July 2009 to June 2010.Soil temperature and soil water content were measured at the same time.Important findings Annual soil respiration of the four types of forests was 1.63,1.79,1.74 and 1.35 μmol CO2·m-2·s-1,and annual heterotrophic respiration was 1.13,1.12,1.12,0.80 μmol CO2·m-2·s-1.Soil respiration and its components displayed obvious seasonal dynamics,with maximum values in summer and minimum values in winter.The soil respiration flux of broad-leaved forest was significantly higher than that of coniferous forests,but there was no obvious differentiation between broad-leaved forests.Soil temperature was the main factor that affected soil respiration and its components,and there were significant exponential relationships between them.There was no significant relationship between soil water content and soil respiration flux,except in broad-leaved forest with a mild inhibition phenomenon.Q10 values of four types of forests were 2.38,2.68,2.99 and 4.24.Soil respiration was more sensitive to temperature along the elevation gradient,while Q10 value increased with eleva-tion increase.

关 键 词：自养呼吸 异养呼吸 Q10值 土壤含水量 土壤温度 

分 类 号：S714[农业科学—林学]