2种更新方式4年生尾巨桉人工林碳储量及其分布特征

Carbon Storage and Distribution of 4-year-old Eucalyptus urophylla ×E. grandis Plantation in Two Regeneration Modes

为了解2种更新方式(植苗更新和萌芽更新)尾巨桉(Eucalyptus urophylla×E.grandis)人工林的碳汇功能,对广西宁明县4年生(中龄林)尾巨桉植苗林和萌芽林碳储量及其分布格局进行研究。结果表明,尾巨桉植苗林和萌芽林各器官中碳含量为456.5~485.3 g/kg,以树叶碳含量最高,其次为树干、树枝、树根,最低为树皮。植苗林和萌芽林生态系统碳储量分别为130.35和138.81 t/hm2,其中乔木层分别占37.46%和42.30%,灌草层分别占0.93%和0.83%,现存凋落物层分别占2.05%和2.23%,土壤层分别占59.56%和54.64%。植苗林和萌芽林乔木层地上部分年净生产力分别为22.21和25.16 t·hm^-2·a^-1,年净固碳量分别为10.58和11.91 t·hm^-2·a^-1,年净吸收CO2量分别为38.79和43.67 t·hm^-2·a^-1。

In order to understand carbon sequestration function of Eucalyptus urophylla×E.grandis plantation in two regeneration modes(planting regeneration and sprouting regeneration),carbon storage and distribution pattern of 4-year-old(middle age)E.urophylla×E.grandis plantations in two regeneration modes were studied in Ningming county of Guangxi.Results showed that carbon contents in different organs of planting forest and sprouting forest ranged from 456.5 to 485.3 g/kg,and the order was leaf>stem>branch>root>bark.Carbon storages of planting forest and sprouting forest ecosystems were 130.35 and 138.81 t/hm2,respectively,of which arbor layer accounted for 37.46%and 42.30%,shrub-grass layer accounted for 0.93%and 0.83%,existing litter layer accounted for 2.05%and 2.23%,soil layer accounted for 59.56%and 54.64%,respectively.Annual net productivities of above-ground parts of arbor layer in planting forest and sprouting forest were 22.21 and 25.16 t·hm^-2·a^-1,respectively.Annual net carbon fixation were 10.58 and 11.91 t·hm^-2·a^-1,and annual net CO2 absorption were 38.79 and 43.67 t·hm^-2·a^-1,respectively.