Abstract: Scientific and accurate estimation of the forest carbon sequestration is the key to evaluate forest functions of mitigating CO₂ concentration in atmosphere and responding to climate change, however the special biological and ecological characters of bamboo greatly increased the difficulty in accounting the carbon sequestration. The biometric approach was used to estimate the carbon density, storage and spatial distribution pattern of the Pleioblastus amarus Forest Ecosystem in Southern Sichuan Province, as well as the annual carbon sink. The results showed: 1) There was not significant difference in carbon density between various ages and organs in stumpage bamboo, and the mean value was 450.792 g ·kg^-1. The mean soil carbon density was 19.410 g ·kg^-1, however there were extremely significant differences in the density between various soil layers. 2) The total carbon storage of the P. amarus forest ecosystem was 156.823 t ·hm^-2, and the carbon stored in soil, stumpage bamboo and litter accounted for 84.5% (132.568 t ·hm^-2), 12.4% (19.432 t ·hm^-2) and 3.1% (4.823 t ·hm^-2), respectively. 3) For the carbon storage in stand bamboo approximate 49.13% was stored in stem. The carbon stored in the over-ground parts and underground parts accounted for 68.68% and 32.32%, respectively. The carbon stock above ground was 2.19 times more than that underground. 4) Carbon sequestration capacity of the P. amarus stand was 8.262 t ·hm^-2a^-1, equivalents to 30.292 t ·hm^-2 of CO₂, greater than Phyllostachys edulis forest ecosystem.

Key words: Pleioblastus amarus, carbon storage, carbon density, carbon sink