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以南京市郊北亚热带次生林为研究对象,于2010年设置挖沟断根和不断根处理小区,观测了土壤呼吸、异养呼吸的季节变异规律,并以此计算了自养呼吸速率,同时,观测了土壤温度、湿度等环境因子.结果表明,土壤呼吸、异养呼吸具有相似的季节变化规律,季节平均土壤呼吸、异养呼吸和自养呼吸速率分别为3.42、2.36和1.06μmol.(m2.s)-1.回归分析表明,异养呼吸随土壤呼吸增大而增加,异养呼吸(y)与土壤呼吸(x)之间的关系可用对数回归方程描述,该方程可解释异养呼吸90.5%(R2=0.905)的季节变异.进一步的分析表明,土壤呼吸不同组分与温度间均存在指数回归关系,描述土壤呼吸、异养呼吸、自养呼吸与温度间关系的指数回归方程可分别解释78.4%、76.4%和65.6%的变异,P值均达到极显著水平(P<0.01).根据回归方程估算的土壤呼吸、异养呼吸和自养呼吸温度系数Q10值分别为1.97、1.76和3.31.本研究表明,在树木生长的3～10月,土壤呼吸自养和异养组分的比例分别为69%和31%,且异养呼吸的温度敏感性显著小于自养呼吸的温度敏感性.
Taking the subtropical secondary forest in suburb of Nanjing as the research object, the trenching ditch and continuous rooting plot were set up in 2010 to study the seasonal variations of soil respiration and heterotrophic respiration. Based on this, the autotrophic respiration rate was calculated. At the same time, Soil temperature, humidity and other environmental factors.The results showed that the soil respiration and heterotrophic respiration had similar seasonal variation, and the seasonal average soil respiration, heterotrophic respiration and autotrophic respiration rate were 3.42, 2.36 and 1.06μmol. (M2.s ) -1. Regression analysis showed that heterotrophic respiration increased with soil respiration, and the relationship between heterotrophic respiration (y) and soil respiration (x) was described by a logarithmic regression equation that explained heterotrophic respiration 90.5 (R2 = 0.905) .Further analysis showed that there existed exponential regression relationship between different components of soil respiration and temperature, and the exponential regression equation describing the relationship between soil respiration, heterotrophic respiration and autotrophic respiration and temperature were respectively Interpretation of 78.4%, 76.4% and 65.6% of the variation, P value reached the significant level (P <0.01) .The soil respiration, heterotrophic respiration and autotrophic respiration temperature coefficient Q10 estimated by the regression equation were 1.97,1.76 and 3.31 The study showed that the soil respiration rate of autotrophic and heterotrophic components was 69% and 31%, respectively, from March to October, and the temperature sensitivity of heterotrophic respiration was significantly less than that of autotrophic respiration Sex.