洞庭湖滩地土壤微生物与土壤呼吸特征分析

摘要

The analyses of the relationship between the dynamics of soil respiration and the number of soil microorganisms were based on three utilization types in beach of Dongting Lake and different time scale, which contributed to the deep understanding of the mechanism of soil respiration dynamics and the factors.The soil respiration of different land utilization types of reeds, farmland, poplar forest in the Dongting Lake beach were tested in field by LI8100 gas analyzer, the diurnal and seasonal changes of soil respiration rate of three different types of land, and the relationship between the soil respiration rate and the number of soil microorganisms were analyzed.The results show that: the obvious differences in three kinds of different land utilization types of soil respiration in seasonal and diurnal changes, and their dynamic performance were all the single-peak type, the occurrence time of peak value were different and the lowest value occurred roughly in 5:00 am.The rank of soil respiration from strong to weak was reeds＞ poplars＞ farmland.There was obvious correlation between the seasonal changes of soil respiration rate and the number of soil bacterium(p＜0.05).There was extremely obvious correlation between the seasonal changes of soil respiration rate and the number of soil ray fungus(p＜0.01).There was no obvious correlation between the seasonal changes of soil respiration rate and the number of soil fungus.Ii is found that the soil respiration was effected by soil microbial communities greatly.%基于洞庭湖滩地3种典型土地利用类型不同时间尺度土壤呼吸速率及土壤微生物数量变化,分析土壤呼吸动态特征与土壤微生物数量之间的关系,深入了解土壤呼吸动态变化特征及影响因子.采用LI-8100气体分析仪对杨树林地、芦苇地、农田地土壤呼吸动态进行野外测定,分析不同土地利用类型土壤呼吸速率的日变化和季节变化,并对土壤呼吸速率与土壤微生物数量之间的关系进行相关分析.结果表明:3种土地利用类型土壤呼吸速率的季节和日变化比较明显,其动态均表现为单峰型,高峰值出现时间存在差异,而最低值大致出现在凌晨5:00;土壤呼吸作用强弱表现为芦苇地>杨树林地>农田地;土壤呼吸速率季节变化与土壤细菌数量变化呈显著相关性(P<0.05),与放线菌数量变化呈极显著相关性(P<0.01),与真菌数量变化相关性不明显,表明土壤呼吸受土壤微生物群落影响较大.