Abstract: This paper chose climax evergreen broadleaf forests (EBLF) as a reference, then selected sub-climax forests, secondary coniferous forests, shrubs and grassland to represent different stages of forest degradation, and 4 logging stands to denote forests damage intensity, in the Tiantong region, Zhejiang province. To understand the impacts of EBLF degradation and damage on soil respiration, soil respiration rate and associated influencing factors were measured among above forests. The results showed that: (1) there was a pronounced seasonal pattern of soil respiration among forests; (2) soil respiration rate was the highest in climax EBLF and the grassland, intermediate in coniferous forests and shrub lands, and the lowest in sub-climax EBLF; (3) the logging did not affect soil respiration rate along the forest damage intensity; and (4) soil respiration was determined by soil C/N ratio and soil pH through forest degradation series; specifically, the main factor in the early stage was soil C/N ratio, and in the later stage of degradation was soil temperature. It was concluded that the controlling factor of soil respiration was shifted from biological-based to abiotic-based orientations, through forest degradation.

Key words: forest degradation, soil properties, carbon sink, carbon source, carbon cycling