2005年4月-2006年3月,选择福建武夷山不同海拔高度上的常绿阔叶林、针叶林、亚高山矮林和高山草甸4个不同的群落作为实验地,每月测量1次土壤呼吸,测定影响土壤呼吸变化的土壤生物与非生物因子(包括土壤温度,土壤湿度,土壤有机碳、氮、硫含量,凋落物量,微生物量以及细根生物量等),研究了土壤呼吸的空间异质性。结果表明:随着海拔的升高,年均土壤呼吸速率显著降低,而土壤碳、氮、硫含量,土壤微生物量以及细根生物量等却增大;常绿阔叶林土壤呼吸速率是高山草甸的1.82倍;土壤呼吸的空间变化只与土壤温度呈显著的相关性;证明在影响土壤呼吸的土壤因子中,土壤温度是调控其在海拔高度上变化的主导因子。
Soil respiration is an important component in carbon cycle ot terrestrial ecosystem. As an index of the metabolic activity of heterotrophie microbes and plant roots, soil respiration shows spatial heterogeneity. In this paper, the monthly soil respiration rate and its regulating abiotie and biotic factors (soil temperature, soil moisture, soil organic carbon, soil total nitrogen, soil total sulfur, soil microbial biomass, and fine root biomass) in four different plant communities ( evergreen broadleaf forest, coniferous forest, subalpine dwarf forest, and alpine meadow) along an elevation gradient in Wuyi Mountain was measured from April 2005 to March 2006. The resuits showed that with increasing elevation, soil respiration rate decreased, while the contents of soil organic carbon, soil total nitrogen, soil total sulfur, soil microbe biomass, and fine root bio- mass increased. Soil respiration rate in evergreen broadleaf forest was 1.82 times as large as that in alpine meadow. The spatial variation of soil respiration linearly correlated with soil tempera- ture. Our findings suggested that among the main soil factors affecting soil respiration, soil temperature was the controlling factor on the vertically spatial variation of soil respiration.