Abstract:

The carbon content and storage were studied in 19yearold Pinus elliottii plantation by sampling plots.The results showed that carbon content in different organs of P.elliottii ranged between (5092±046)% and (5438±026)%，and decreased in the order of leaf>branch>wood>root >bark.The carbon content in branch and leaf increased with the aging of organs.The leaf carbon content of midlayer was slightly higher than that of the mid and up layers.And the branch carbon content of the downlayer was much higher than that of the other two layers.The carbon content in shrub，herb and litter floor were（4516±04）%，(4228±041)%，and (4088±031)%，respectively.The average carbon content in the soil was (043±004)% and declined with the increase of soil depthThe total carbon storage in P.elliottii plantation ecosystem amounted to 12194 t〖DK〗·hm-2，of which the overstorey stored 8618 t〖DK〗·hm-2 accounting for 7067% of the total storage.The carbon storage in understorey，litter floor and soil within the depth from 0 to 60 cm were 06 t〖DK〗·hm-2，886 t〖DK〗·hm-2 and 263 t〖DK〗·hm-2，accounting for 049%，727% and 2157%，respectively.The annual net carbon storage of P.elliottii forest was 454 t〖DK〗·hm-2 and the annual net O2 production was 1212 t〖DK〗·hm-2.The annual net benefits from CO2 fixation and O2 production of P.elliottii plantation was estimated to be 9 034 yuan〖DK〗·hm-2 by reforestation cost method.The data would provide scientific guideline for the protection of ecosystem and reasonable utilization of present resource.

Key words: CO2 fixation and O2 production, ecoenvironment benefit, 〖WTBX〗Pinus elliottii〖WTBZ〗 plantation, subtropical red earth hilly area