Abstract: Based on the biomass investigation，  this paper evaluated the carbon storage and its allocation in a 27-year-old Tsoongiodendron odorum plantation ecosystem in southern subtropical region of China. In the ecosystem, the total biomass of vegetation layer was 101.26 t·hm^-2, and the biomass of tree layer occupied 86.90%. The carbon storage in various organs of the trees ranged from 426.5 to 496.9 g·kg^-1, with the order of trunk > branch > dead branch > root tip > coarse root > leaf > middle root > bark > fine root. The total carbon storage of the ecosystem was 180.49 t·hm^-2, and the carbon storage in 0-80 cm soil layer was 2.67 times of that in vegetation layer. The annual net carbon sequestration of the tree layer was 3.07 t·hm^-2·a^-1, mostly in aboveground part.

Key words: Agriculture-animal husbandry ecotone, Land use, Resources