喀斯特地区3种林型土壤呼吸及其影响因子  

Soil Respiration and Impact Factors of 3 Forest Types in Karst Regions

作　　者：丁访军 高艳平 吴鹏 崔迎春 胡蕖 

机构地区：[1]贵州省林业科学研究院,贵州贵阳550005

出　　处：《水土保持学报》2010年第3期217-221,237,共6页Journal of Soil and Water Conservation

基　　金：贵州省林业厅重点项目(2006-21);国家林业局公益专项子项目(200704005/WB03);贵州省科技厅项目(黔科合院所创能[2009]4002)

摘　　要：以黔中喀斯特地区的灌木林、阔叶混交林和针阔混交林3种林型为对象,采用LI-6400-09便携式土壤呼吸室对其土壤呼吸速率进行了连续定位观测。结果表明,3种林型土壤呼吸速率均呈现明显的季节性变化,表现出夏季>秋季>春季>冬季,土壤呼吸速率全年平均值分别为2.51,2.23,2.06μmol/(m2.s),变异幅度达5.99～7.32,但3种林型土壤呼吸速率差异不明显;3种林型的土壤呼吸速率均与5 cm,10 cm,15 cm处土温和林内气温具具很强的正相关关系,且均与5 cm,10 cm和15 cm处土温呈较高的指数正相关,从土壤呼吸速率与10cm处土温的回归方程的拟合度来看,模型的拟合表现为针阔混交林最好,阔叶混交林次之,灌木林相对较差;3种林型的土壤呼吸速率均与地表0-10 cm的土壤体积含水率呈负相关关系,且表现为灌木林(-0.686)>阔叶混交林(-0.646)>针阔混交林(-0.599),与10-20 cm和20-30 cm两层的关系表现各异;3种林型的土壤呼吸对温度的敏感系数(Q10值)存在差异,表现为阔叶混交林(3.19)>针阔混交林(2.69)>灌木林(2.02),且与其它森林生态系统Q10值相符。LI-6400-09 portable soil respiration fitting equipment is employed in this study to carry on continuous observation on the soil respiration rates with the 3 forest types,shrubs,mixed broadleaf and mixed conifer and broadleaf in karst areas in the middle parts of Guizhou being the study objects.The results indicate that there are distinct seasonal changes in soil respiration rates of the three forest types,and they are summer,autumn,spring and winter in decreasing order.The average annual soil respiration rate of the three forest types is 2.51,2.23,2.06 μmol/（m2·s） respectively,with amplitude of variation being from 5.99 to 7.32,while the difference between the forest types in soil respiration rates is little.There are significant positive correlations between soil respiration rates and soil temperature in 5 cm,10 cm and 15 cm soil depth,with considerably high exponential positive correlations between them,and the air temperature inside the forests.As to the degree of fitting on the regression equations between the soil respiration rate and soil temperature at 10 cm depth,they are mixed conifer and broadleaf,mixed broadleaf and shrubs in decreasing order.Soil respiration rates show negative correlations with the bulk moisture of soil at 0 to 10 cm depth,with shrubs（-0.686）,mixed broadleaf（-0.646） and mixed conifer and broadleaf（-0.599） in decreasing order.And there are various relations between them in soil from 10 cm to 20 cm and from 20 cm to 30 cm.The different sensitivity coefficients to temperature,Q10,are mixed broadleaf（3.19）,mixed conifer（2.69）and broadleaf and shrubs（2.02）,which is in line with Q10 of other forest ecosystems.

关 键 词：土壤呼吸 土壤温度 土壤水分 喀斯特 林型 

分 类 号：S718.51[农业科学—林学]