【作者】 周利光；

【导师】 魏江生；

【作者基本信息】 内蒙古农业大学 ， 土壤学， 2010， 硕士

【摘要】 成熟林土壤呼吸作为成熟林土壤碳积累中重要的输出部分,是估测成熟林生态系统碳积累非常重要的研究内容。本研究采用红外气体分析法和挖壕法对不同海拔梯度成熟林土壤呼吸(RS)及根系自养呼吸(RA)和异养呼吸(RH)的土壤表面CO2通量及其影响因子进行了测定及分析研究。初步揭示了沿海拔梯度变化土壤呼吸的变化规律,对于正确评估我国成熟林在全球气候变化背景下的碳汇、碳源功能的研究提供了基础科学数据。研究结果表明:1研究区土壤呼吸日变化特征为:常绿阔叶林(780m)、常绿落叶阔叶混交林(1670m)日变化基本呈单峰型曲线,最高值大约12:00～16:00,最低值大约5:00～6:00)。落叶阔叶林(1970m)、高山针叶林(2570m)日变化基本呈双峰型曲线,10:00左右和19:00左右,最低值出现在2:00左右。研究区土壤呼吸季节变化特征为:土壤呼吸速率变化表现为7月前落叶阔叶林>常绿阔叶林>常绿落叶阔叶混交林>高山针叶林。7月土壤呼吸速率表现为高山针叶林>常绿阔叶林>常绿落叶阔叶混交林>落叶阔叶林。7月后土壤呼吸速率表现为常绿阔叶林>落叶阔叶林>常绿落叶阔叶混交林>高山针叶林。2生长季土壤CO2释放通量常绿阔叶林(780m)436.87gC m-2、常绿落叶阔叶混交林(1670m)394.90 gC m-2、落叶阔叶林(1970m)438.77 gC m-2、高山针叶林(2570m)316.68 gC m-2。各森林生态系统(除常绿落叶阔叶混交林)土壤呼吸中根系呼吸贡献率(RC)为23.05%～28.23%;常绿落叶阔叶混交林RC贡献率仅为10%左右。研究区异养呼吸贡献率为76.34%～91.35%,显著高于根系呼吸贡献率。3研究区成熟林的RS与土壤10cm处的温度均呈显著正相关关系(R2=0.564～0.629;p<0.01),土壤含水量对RS影响均不显著(p>0.05)。在自然条件下,研究区内不同海拔梯度的RS主要受土壤温度的影响,而水分不是限制该地区土壤呼吸的主要因子。更多还原

【Abstract】 As a important part of the output of soil carbon of the mature forest, the soil respiration is the estimation confined the mature forest ecosystem carbon accumulates the very important research content. We used trenching-plot and infrared gas exchange analyzer approaches to determine heterotrophic(RH) and autotrophic respiration(RA)in soil surface CO2flux for mature forest of different elevation gradient which is also preliminary show the rule and provide the basic science data for the correct estimation of carbon assembling and the function of the carbon source of Chinese mature forest in the global climate.The research shows that the evergreen broad-leaf wood(780m) and the evergreen and fallen broad-leaf mix wood(1670m) diurnalvariation assumes the unimodal curve basically. The maximum value appears at 12:00~16:00,and the minimum value appears at 5:00~6:00. The fallen and broad-leaf wood (1970m), the mountain coniferous wood (2570m) diurnalvariation assumes the split-blip curve basically, which of the maximum value appears at about 10:00 and 19:00, the minimum value appears at 2:00. The research area soil breath seasonal variation characteristic is: Before July, the soil respiration speed change performance shows as: the fallen broad-leaf wood > the evergreen broad-leaf wood > the evergreen and fallen broad-leaf mix wood > the mountain coniferous wood. In July, the mountain coniferous wood > the evergreen broad-leaf wood > the evergreen and fallen broad-leaf mix wood > the fallen broad-leaf wood. After july, the evergreen broad-leaf wood>the fallen broad-leaf wood>the evergreen and fallen broad-leaf mix wood>the mountain coniferous wood.2 The CO2 flux of vegetation season of every type wood is:: the evergreen broad-leaf wood(780m)436.87gC m-2,the evergreen and fallen broad-leaf mix wood(1670m)394.90 gC m-2,the fallen broad-leaf wood(1970m)438.77gCm-2,the mountain coniferous wood(2570m) 316.68 gC m-2. The contribution rate of the root respiration in the soil respiration of every forest ecosystem is 23.05%~28.23%. The RC of the evergreen and fallen broad-leaf mix wood is only about 10%. The contribution rate(RC) of the heterotrophic respiration in the research area is 76.34%～91.35% which is obviously higher than the contribution rate of root respiration.3 The RS of research area mature forest and temperature of the soil 10cm below assumes the remarkable correlational dependence(R2=0.564～0.629;p<0.01). The soil moisture content is not remarkable to the RS influence(p>0.05). Under natural condition, in research area, the different elevation gradient RS mainly influenced by soil temperature, but the moisture content is not the main factor to local soil respiration.更多还原