Carbon Accumulation and Distribution Characteristics of the Evergreen Broad-leaved and Deciduous Broad-leaved mixed forests in East Guizhou

Abstract

1 贵州省林业科学研究院, 贵阳摇 550005 2 贵州省三都县林业局, 三都摇 558100 摘要:以雷公山自然保护区常绿落叶阔叶混交林为研究对象,对其碳素含量、碳密度及分配特征进行了研究。 结果表明:生态系 统碳素含量表现为乔木层(418.58 g / kg) >灌木层(387.26 g / kg) >草本层(382.80 g / kg) >枯落物层( 378.11 g / kg) >土壤层( 31.48 g / kg) ,差异极显著( P ﹤ 0.01) ,乔木不同器官表现为干>根>叶>枝,差异不显著( P >0.05) ,灌、草层均表现为地上>地下,土壤 碳素含量随土层深度的增加而减少;生态系统碳密度为 234.68 t / hm 2 ,表现为土壤层( 170.00 t / hm 2 ) >乔木层( 57.02 t / hm 2 ) >枯 枝落叶层(5.48 t / hm 2 ) >灌木层(1.81 t / hm 2 ) >草本层(0.37 t / hm 2 ) ,分别占生态系统碳密度的 72.44%、24.30%、2.34%、0.77%和 0.16%;植被层碳密度为 58.79 t / hm 2 ,占了生态系统碳密度的 25.09%;乔木层各器官以树干的碳密度最高,占了乔木层碳密度 52.43%;灌木层、草本层地上部分碳密度分别是地下部分的 2.85 倍 1.64 倍;土壤表层(0-20 cm) 碳密度为 70.40 t / hm 2 ,显著高 于其它各层( P ﹤ 0.001) ,占了土壤(0-80 cm) 碳密度的 41.41%,有很强的表聚性,因此,防止地表的水土流失,可有效保持土 Abstract: This study was conducted to determine forest carbon content, density, and the characteristics of carbon distribution in the Evergreen Broad鄄leaved and Deciduous Broad鄄leaved mixed forest in Lei Gongshan Nature Reserve, Guizhou, China. Results indicated carbon content in the ecosystem varied significantly ( P < 0.01) between trees, shrubs, herbs, litter and soil: 418.58 g / kg, 387.26 g / kg, 382.80 g / kg, 378.11 g / kg, and 31.48 g / kg, respectively. Among the various organs of a tree, the carbon content was distributed as follows: trunks > roots > leaves > branches. For shrubs, the carbon content was distributed as: stems > leaves > roots. For herbs, the above ground carbon content was higher than the below ground carbon content, while for all of them, the differences in carbon content among the different organs of a tree, shrub or herb was insignificant ( P > 0. 05) . The average carbon content of all vegetation was 40. 02%, when all types ( trees, shrubs, and herbs) and all plant organs were considered. The carbon content in the litter of the un鄄decomposed layer was higher than in the semi鄄decomposed layer, though the difference was not significant ( P > 0.05) . The soil carbon content was highest in the soil at a depth of 0 to 20 cm and soil carbon content generally decreased inversely and significantly with soil depth ( P < 0. 01) . The most of the carbon in the entire ecosystem ( 234. 68 t / hm 2 ) was divided 3.1.2摇 林下植被层及土壤层碳素含量 灌木层不同器官的碳素含量介于 370.92-408.17 g / kg 之间,平均为 387.26 g / kg,不同器官碳素含量表现 为枝干>叶>根,变异系数介于 6.08%-13.91%之间,草本层不同器官碳素含量表现为地上部分(416.27 g / kg) >地下部分(349.33 g / kg) ,平均为 382.80 g / kg,变异系数介于 12.23%-13.56%之间( 表 4) ,灌木层和草本层 不同器官的碳素含量差异均不显著( P>0.05) 。 不论灌木和草本,其地上部分碳素含量均高于地下部分。 灌 木层的碳素含量高于草本层,表现出随植物个体高度或组织木质化程度的降低,其碳素含量相应减少的趋 势 [6,13] 。 枯落物层碳素含量表现为未分解层(382.25 g / kg) >半分解层(373.98 g / kg) ,平均为 378.11 g / kg,变 异系数介于 2.24%-2.63%之间( 表 4) ,各层的碳素含量差异不显著( P>0.05) 。 土壤不同层次碳素含量在 17.08-58.23 g / kg 之间,平均值为 31.48 g / kg,变异系数介于 16.82%-43.03% 之间,0-20 cm 土层的碳素含量最高,为 58.23 g / kg,表现为随土层深度的增加而减少的趋势( 表 4) ,且差异 极显著( P< 0.01) ,说明森林土壤碳含量的分布有较强的表聚性。 这主要是由于地表凋落物的积累和分解使 得土壤表层有机质具有稳定而丰富的来源,同时植被根系对土壤表层有机碳的累积发挥了很强的作用 [20鄄 21] 。 多重比较结果表明:0-20 cm 和 20-40 cm、40-60 cm、60-80 cm 土层的有机碳含量差异极显著( P<0.01) ; 20-40 cm 和 40-60 cm、60-80 cm 土层有机碳含量差异显著( P<0.05) ;40-60 cm 和 60-80 cm 土壤有机 碳含量差异不显著( P>0.05) 。 4 6 7 1 摇 生摇 态摇 学摇 报...