Abstract:

Carbon accumulation and spatial distribution as well as their variations in three different age (8-year-old, 14-year-old and 28-year-old) stands of Taiwania flousiana plantation ecosystem were investigated in Nandan Shankou Forestry Station of Guangxi, China. The results showed that carbon content in different organs of T.flousiana ranged form 418.4 g·kg^-1 to 516.4 g·kg^-1, which was in order as follows: bark＞branch＞stem＞root＞leaf. The vertical distribution of carbon content within the stand was in the following order：tree layer＞shrub layer＞herb layer.Carbon content in the soil obviously declined with increased soil depth from 0 to 80 cm. Total carbon storage in the ecosystems was 159.37, 194.21 and 278.22 t·hm^-2, respectively for 8-year-old, 14-yea-old and 28-yea-old stands. The tree layer in the three-age stands respectively accounted for 18.30%、28.37% and 43.59%; the shrub and herb layers for 0.14%、1.17% and 1.44%; the litter layer for 0.33%、0.89% and 1.11%; the soil for 81.23%、69.58% and 54.78% of the total storage of carbon. Carbon storage in different organs was roughly in proportion to the biomass of corresponding organ. For example, stem occupied the greatest proportion of carbon storage in the trees, up to 46.37%, and increased with the stand age while branches, leaves, bark and roots occupied more than 37.32%. The annual net productivity of the 8-year-old,14-year-old and 28-year-old T.flousiana plantation was respectively 8.93, 10.82 and 12.53 t·hm^-2a^-1, and annual net carbon storage was respectively 4.19, 5.07 and 5.93 t·hm^-2a^-1.

Key words: Taiwania flousiana plantation, stands age, carbon content, carbon storage, carbon distribution