【摘要】 为探明杨柴人工林土壤呼吸各组分动态变化及其与水热因子的关系,在毛乌素沙地选取30 a的杨柴人工林样地,采用壕沟法对土壤呼吸组分进行分离,利用Li-8100土壤碳通量测量系统进行土壤呼吸定位观测研究。结果表明:（1）在生长季5—10月,杨柴人工林土壤总呼吸、异养呼吸和自养呼吸速率均呈显著季节变化规律,表现为6—8月高、5月和10月低的单峰型曲线变化,各组分平均值分别为2.16μmolC·m^-2·s^-1、1.65μmolC·m^-2·s^-1和0.39μmolC·m^-2·s^-1。（2）杨柴人工林土壤总呼吸、异养呼吸和自养呼吸碳通量分别为354.80 gC·m^-2、270.79 gC·m^-2和84.01gC·m^-2,其中异养呼吸和自养呼吸分别占土壤总呼吸碳通量的76.32%和23.68%,异养呼吸贡献显著高于自养呼吸。（3）土壤呼吸各组分速率均与土壤温度呈极显著指数相关关系,与土壤含水量无显著相关性,温度和水分的交互作用对土壤呼吸作用具有极显著的驱动作用。（4）用土壤温度拟合土壤总呼吸、异养呼吸和自养呼吸速率得出相应的温度敏感性指数(Q₁₀)值分别为1.57、1.51和1.97。更多还原

【Abstract】 In Mu Us Sandy Land, 30-year Hedysarum laeve forest land was selected for field monitoring, components of soil respiration were divided by use of trench method, and the location observation of soil respiration was carried out with Li-8100 soil carbon flux measurement system. The results showed:（1） During the growing season from May to October, the rate of total soil respiration, heterotrophic respiration and autotrophic respiration in Hedysarum laeve plantation changed in obvious seasonal variation patterns, presenting a single peak pattern of being high from June to August and being low in May and October, with the average value of 2.16 μmolC·m^-2·s^-1, 1.65 μmolC·m^-2·s^-1 and 0.39 μmolC·m^-2·s^-1 respectively.（2） The carbon fluxes of soil respiration, heterotrophic respiration and autotrophic respiration of Hedysarum laeve plantation were 354.80 gC·m^-2, 270.79 gC·m^-2and 84.01 gC·m^-2 respectively, of which heterotrophic respiration and autotrophic respiration took up for 76.32% and 23.68% of the carbon fluxes of soil respiration respectively, and heterotrophic respiration was significantly higher than autotrophic respiration.（3） There was an extremely significant exponential correlation between each component of soil respiration in Hedysarum laeve plantation and soil temperature, and there was no correlation between them and soil water content. The interaction of temperature and water was of great significance in promoting soil respiration.（4） Different Q₁₀ values were obtained by fitting soil respiration, heterotrophic respiration and autotrophic respiration with soil temperature, which are 1.57, 1.51 and 1.97 respectively.更多还原