Abstract: Soil respiration is an important component in carbon cycle of terrestrial ecosystem. As an index of the metabolic activity of heterotrophic microbes and plant roots, soil respiration shows spatial heterogeneity. In this paper, the monthly soil respiration rate and its regulating abiotic 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 results 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 biomass 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 temperature. 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.

Key words: Tropical wet seasonal rainforest, Secondary forest, Biomass, Biomass partition, Fruit yield, Amomum villosum cultivation