川中丘陵区人工桤柏混交林根呼吸对土壤总呼吸的贡献  

Contribution of Root Respiration to Soil Respiration in a Alder and Cypress Mixed Plantation in Hilly Areas of Sichuan Basin

作　　者：王小国[1] 朱波[1] 高美荣[1] 郑循华[2] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院大气物理研究所,北京100029

出　　处：《山地学报》2009年第3期270-277,共8页Mountain Research

基　　金：国家自然科学基金重点项目(40331014);国家重点基础研究发展计划项目(2005CB121108);中国科学院成都山地所人才基金项目~~

摘　　要：采用挖壕沟法和根系生物量外推法对桤柏混交林地根呼吸在土壤总呼吸的贡献进行了为期1 a的对比研究。研究表明,两种方法测得的根呼吸平均速率分别为0.64μmol CO2/(m2.s)和0.54μmol CO2/(m2.s),挖壕沟法高于根系生物量外推法的测定结果。两种方法计算的根呼吸占土壤呼吸的比例具有明显的季节变化,均表现为夏季(5～6月)较高而冬季(1～2月)较低,变化范围分别为13%～51%、11%～56%,平均分别为34%和31%;林木生长季节根呼吸比例均高于非生长季,两种方法测定的林木生长季根呼吸比例分别为41%和38%。方差分析表明两种方法测定根呼吸比例之间差异不显著(p>0.05)。The contribution of root respiration to total soil respiration is one of the most interesting, important, and methodologically complicated problems in the study of the carbon budget in soils and the subdivision of the CO2 emission from soils into separate fluxes. Many researches showed that the methods themselves may be an important source of great differences between the contributions of root respiration to total soil respiration. But the comparison of methods under similar or same experimental conditions is relatively rare. A trenching method and root biomass regression method were used to determine the contribution of root respiration to total soil respiration in a subtropical forest ecosystem. The contributions of root respiration to total soil respiration estimated by trenching metho.d and root biomass regression method in the growing season were 41% and 38%., and the average of root respiration contributions were 34% with the range of 13% -51%, and 31% with the range of 11% -56% over the observation period, respectively. There was no significant difference between the monthly attributions of root respiration to total soil respiration estimated by two methods （p 〉0.05 ）.

关 键 词：土壤呼吸 根呼吸 挖壕沟法 根系生物量外推法 

分 类 号：S152.4[农业科学—土壤学]