不同林龄刺槐人工林碳储量及分配规律

为研究林龄对刺槐林生态系统碳储量的影响,在样地调查与实测生物量的基础上,对河南省洛宁县灌木林人工改造的8、15和22年生刺槐人工林进行了研究,测定了刺槐林及同区域灌木林不同层次的的碳含量(乔木层、灌草层、枯落物层和土壤层(0~50 cm)),结合生物量及土壤数据分析其生态系统的碳储量和层次分布特征。结果表明,刺槐各器官碳含量在42.60%~50.92%之间,大小顺序为:树干树皮树枝根桩树叶粗根小根大根中根细根;各林分的灌草层、枯落物层碳含量无显著差异;土壤层碳含量均表现为随土壤深度增加而降低,而随着种植年限的增加而增加;灌木林及8、15和22年生刺槐人工林生态系统碳储量分别为78.96、99.78、110.85和132.75 t·hm-2,对比灌木林,8、15和22年生刺槐林碳储量年均增长量分别为2.60、2.13和2.44 t·hm-2·a-1;乔木层及土壤层是刺槐人工林生态系统碳储量的主要来源,两者占生态系统碳储量85.14%~96.63%。随种植年限增加刺槐林土壤层碳储量所占比重下降而乔木层碳储量比重逐渐上升,灌草层、枯落物层碳储量无明显变化规律。

Characteristics of carbon storage and sequestration in different age Robiniapsedudoacia plantations

In order to identify the age-sequence of Robiniapsedudoacia plantations on ecosystem carbon storage, a survey was conducted in 8-, 15- and 22-year-old Robiniapsedudoacia plantations and shrubwood in Luoning County, Henan Province. The carbon content in the arborous layer (different organs), shrub-grass layer, litter layer and soil layer (0-50 cm) was determined. The ecosystem carbon storage along with characteristics was analyzed based on the biomass and the data analysisi of the soils. The result showed that the carbon content in Robiniapsedudoacia organs ranged from 42.60% to 50.92%, with an ascending order of trunk, bark, branch, rootstock, leaf, thick root, rootlet, big root, medium root, and fine root. There was no significant difference in carbon content in the shrub layer, herb layer and litter layer among the four stands. The carbon storage in these four ecosystems was 78.96, 99.78, 110.85 and 132.75 t.hm^-2, respectively. Compared with the shrub wood, the annual mean increments of carbon pool in the 8-, 15- and 22-year-old Robiniapsedudoacia plantations were 2.60, 2.13 and 2.44 t·hm^-2·a^-1, respectively.The arbor and soil layers were the main carbon pools, which contributed 85.14%-96.63% of the total. The carbon content in the arbor layer increased with an increase of the stand age, while it decreased in the soil layer. In other layers, however, no significant changes were observed in this study.