杉木人工林C库与C吸存的动态研究

对湖南会同10年生、14年生杉木人工林C库和C吸存的动态研究结果表明,杉木人工林生态系统的C库主要由植被层、死地被物层、土壤层组成的,按其C库大小顺序排列为土壤层>植被层>死地被物层。10年生、14年生杉木林生态系统的C库分别为120.52和171.40t.hm-2,具有一定的年龄阶段和地带性特点。随着杉木林年龄的增长,乔木层C贮量的优势逐渐加强,从10年生的30.38t.hm-2增加到14年生的61.24t.hm-2,分别占总C库的25.21%和38.50%,树干C贮量占林分C贮量的比例最大,可达47.17%以上,并随杉木林年龄的增长而明显增强,分布在枝、叶、皮和根中的C贮量占48.11%以上,地上部分的C贮量占总C贮量的84.73%以上。10年生和14年生林地土壤层(0~60cm)的C库分别为88.21和108.20t.hm-2,占生态系统总C库的63.13%以上,土壤表层(0~15cm)的C储量分别占土壤总C库的36.57%和34.26%,土壤0~30cm层中的C储量分别占土壤总C库的63.44%和61.05%。地上部分C贮量与地下部分C贮量之比为10年生时为1∶3.53,14年生时为1∶2.22。10年生和14年生杉木人工林生态系统的年净固定C量分别为5.488和9.285t.hm-2.a-1。湖南省现有杉木林植被C库为0.1916×108t,潜在C库为1.4710×108t,C吸存潜力为1.2794×108t,湖南省现有杉木林植被的C库仅为其潜在C库的13.03%,低于全国水平26.46%。

Dynamic of carbon stock and carbon sequestration in Chinese fir plantation

The dynamic of carbon stock and carbon sequestration in Chinese fir plantation at 10-year-old and 14-year-old were researched in Huitong,Hunan Province. The carbon stock of Chinese fir plantation ecosystem was mainly consisted of three sections,that was the trees,the litter and the soil,and the order of whose carbon stock could be ranked as follow:the soil>the trees>the litter. Carbon stock of Chinese fir plantation was 120.52 t·hm -2 at the 10-year-old and 171.40 t·hm -2 at the 14-year-old,with characteristics of age stage and zone. Superiority of carbon storage in the trees gradually strengthen with the forest stands age growth,carbon storage of the trees had gone up from 30.38 t·hm -2 at the 10-year-old to 61.24 t·hm -2 at the 14-year-old,occupied 25.21% and 38.50% of total carbon stock of the whole ecosystem respectively,carbon storage of different organs was basically direct proportion with its biomass,carbon storage of the trunk occupied the greatest proportion of that in the trees,up to 47.17%,and increased with the forest stands age growth,that in branches,leaves,bark and roots occupied more than 48.11%,and that of aboveground accounted for more than 84.73%. Carbon storage in forestlands soil layer(0～60 cm)at the 10-year-old and the 14-year-old Chinese fir forestlands soil was up to 88.21 and 108.20 t·hm -2 respectively,accounting for more than 63.13% of carbon storage in the whole ecosystem,carbon storage of the surface soil(0～15 cm)layer at the 10-year-old and the 14-year-old Chinese fir forestlands held 36.57% and 34.26% of that in the soil layer(0～60 cm)respectively,and that of the soil layer(0～30 cm)took up 63.44% and 61.05% of that in the soil layer(0～60 cm)respectively. The ratio of carbon storage of aboveground to that of underground at the 10-year-old and the 14-year-old Chinese fir plantation ecosystem was 1∶3.53 and 1∶2.22 respectively,and decreased as the Chinese fir forest age growth. The annual net carbon amount of the 10-year-old and the 14-year-old Chinese fir plantation was respectively up to 5.488 and 9.285 t·hm -2 ·a -1 . Extant carbon storage,potential carbon storage and potentiality of carbon sequestration of Chinese fir forest vegetation in Hunan Province was 0.191 6×108 t,1.471 0×108 t and 1.279 4×108 t respectively,extant carbon storage was only accounting for 13.03% of potential carbon storage,was less than the whole national level 26.46%.