Abstract:

Carbon density,carbon stock and sequestration was made in <i>Alnus cremastogyne</i> plantation ecosystem.The result shows that the arithmetic average carbon density of different organs was 478.8 g·kg^-1 for the 5-year-old plantation,485.7 g·kg^-1 for the 8-year-old stand and 495.8 g·kg^-1 for the 14-year-old plantation,and the variation coefficient ranged form 0.25% to 9.58%.The carbon densities of different organs varied in the following order:stems＞branches＞leaves＞roots＞bark.No obvious trends were detected for the carbon densities in different groups of under-storey of plants or the duff layer as the forest aged.The soil carbon density increased along with the stands aged and declined with the soil depth in the different age classes <i>Alnus cremastogyne</i> plantation.The carbon storage in different oranges was positively related to the biomass of corresponding organs.Superiority of carbon storage in the trees gradually strengthens as the forest stands aged,carbon storage of the trees had gone up from 25.88 t·hm^-2 for the 5-year-old to 49.63 t·hm^-2 for the 14-year-old plantation.The carbon stock of <i>Alnus cremastogyne</i> plantation ecosystem was mainly consisted of three sections,that was the trees,the litter and the soil,<i>cremastogyne</i> plantation was 95.89 t·hm^-2 at the 5-year-old,122.12 t·hm^-2 at the 8-year-old and 130.75 t·hm^-2 at the and the order of whose carbon stock could be ranked as follow:the soil＞the trees＞the litter.Carbon stock of <i>Alnus</i> 14-year-old.Carbon storage in forestlands soil layer (0～60 cm) accounted for more than 59.42% of carbon storage in the whole ecosystem,the ratio of carbon storage of aboveground to that of underground deceased as the <i>Alnus cremastogyne</i> forest age growth.The annual carbon amount of the 5-year-old,the 8-year-old and the 14-year-old <i>Alnus cremastogyne</i> plantation was respectively 6.51,6.26 and 7.82 t·hm^-2 ·a^-1 .Extant carbon storage of <i>Alnus cremastogyne</i> plantation in Hunan province was up to 2.803 4×l0⁶ t,accounting for 47.51% of its potential carbon storage.

Key words: <, i>, Alnus cremastogyne<, /i>, plantation, carbon density, carbon stock, carbon sequestration