湖南省杉木林植被C贮量动态特征

Dynamics of carbon storage of Chinese fir in Hunan Province

杉木林在我国森林系统中的碳汇贡献不可忽视。基于湖南省林业厅2003~2010年森林资源统计年报数据,根据生物量-蓄积量回归模型,估算了湖南省杉木林植被的碳贮量和碳密度。结果表明：2003~2010间,湖南省杉木林植被碳贮量从26.22×106t增至33.06×106t,后降至32.92×106t。幼龄林、中龄林的C贮量逐年下降,而近熟林、成熟林、过熟林的C贮量逐年上升。在此期间,用材林、防护林的碳贮量分别占总杉木林碳贮量的62.3%~80.5%,11.6%~31.9%。在14个地州市中,怀化市杉木林碳贮量最高,2010年达6.45×106t;湘潭市最小,仅0.34×106t。2010年,湖南省杉木林植被碳密度是12.05 t/hm2,较2003年增加了1.68 t/hm2,但远低于中国森林植被的碳密度平均值（41.32 t/hm2）。2005、2010年,湖南省杉木林植被碳密度均表现出南高北低;由西到东无明显规律。

Chinese fir ecosystem plays an important role in carbon storage of whole forest ecosystem in China because of its tremendously solid carbon potential.The carbon storage and density of Chinese fir forest vegetation in Hunan Province were estimated based on the data from the forest resource inventory（2003 ~ 2010） and the model of forest biomass and volume.The results show that the carbon storage of Chinese fir increased from 26.22×106t to 33.06×106t and then decreased to 32.92×106t between 2003 and 2010.The carbon storage of young growth,immature timber decreased from 2003 to 2010,while the carbon storage of near-mature plantation,mature forest and overmature forest showed a rising trend.During the study period,the carbon storage of timber forest and shelter-forest were 62.3%~80.5%,11.6%~31.9% of total Chinese fir forest carbon storage,respectively.The dynamic of carbon storage in timber forest and shelter-forest will greatly affect the function of whole Chinese fir plantations as carbon source and sink.Among 14 prefectures,Huaihua possessed the largest carbon storage of 6.45×106t in 2010,while the smallest carbon storage occured in Xiangtan city,only 0.34×106t.The carbon density of Chinese fir in Hunan province increased 1.68 t/hm2from 10.37 t/hm2in 2003 to 12.05 t/hm2in 2010,which was also much lower than the mean carbon density of China forest vegetation（41.32 t/hm2）.The carbon density of Chinese fir showed a generally increasing trend with increasing latitude,and there was no obvious rule occurred from east to west in Hunan province.