万木林保护区柑橘和锥栗园土壤呼吸的比较

采用Li-8100开路式土壤碳通量系统,对福建省万木林保护区内柑橘和锥栗两果园土壤呼吸进行1年的定位观测,分析了土壤水热因子及人为管理措施对土壤呼吸的影响.结果表明:柑橘和锥栗园样地土壤的呼吸速率月变化均呈单峰型曲线,峰值分别出现在7月(3.76 μmol·m-2·s-1)和8月(2.69 μmol·m-2·s-1)；柑橘和锥栗园样地土壤呼吸速率的年均值分别为2.68和1.55 μmol·m-2·s-1,且柑橘园土壤呼吸速率极显著高于锥栗园；土壤温度是影响土壤呼吸的主要因素,可以解释土壤呼吸速率月动态变化的73％～86％；锥栗园土壤含水量与土壤呼吸速率呈显著正相关,但柑橘园两者关系不显著；指数方程计算的柑橘和锥栗园土壤呼吸的Q10值分别为1.58和1.75;柑橘和锥栗园土壤呼吸年通量值分别为10.01和5.77tC·hm-2 ·a-1.

Dynamic changes of soil respiration in Citrus reticulata and Castanea henryi orchards in Wanmulin Nature Reserve, Fujian Province of East China

From January 2009 to December 2009, the soil respiration in the Citrus reticulata and Castanea henryi orchards in Wanmulin Nature Reserve was measured with Li-8100, aimed to characterize the dynamic changes of the soil respiration and its relationships with soil temperature and moisture in the two orchards. The monthly variation of the soil respiration in the orchards was single-peaked, with the peak appeared in July (3.76 micromol x m(-2) x s(-1)) ) and August (2.69 micromol x m(-2) x s(-1)). Soil temperature was the main factor affecting the soil respiration, and explained 73%-86% of the monthly variation of soil respiration. The average annual soil respiration rate was significantly higher in Citrus reticulata orchard than in Castanea henryi orchard, with the mean value being 2.68 and 1.55 micromol x m(-2) x s(-1), respectively. There was a significant positive correlation between the soil respiration rate and soil moisture content in Castanea henryi orchard, but less correlation in Citrus reticulata orchard. The Q10 value of the soil respiration in Citrus reticulata and Castanea henryi orchards was 1.58 and 1.75, and the annual CO2 flux was 10.01 and 5.77 t C x hm(-2) x a(-1), respectively.