亚热带日本落叶松中、幼龄林土壤有机碳密度和分配特征

本文基于32块样地土壤数据,对亚热带日本落叶松中、幼龄林的土壤有机碳密度及其分配特征进行了分析,结果发现:(1)中龄林的有机碳含量、有机碳密度明显高于幼龄林;(2)混交林的有机碳含量、有机碳密度明显高于纯林;(3)0~80 cm的土壤有机碳密度为172.25 t/hm2。有机碳主要集中在表土层0~20 cm处,此表土层有机碳密度分别是土层20~40 cm、40~80 cm的175.21%、129.52%。在土层相同的情况下,随着土壤深度的增加,其土壤有机碳密度呈下降趋势;(4)与适宜亚热带地区生长的造林树种——杉木相比,日本落叶松林的土壤有机碳含量、土壤有机碳密度均明显高于20年生杉木人工林,说明日本落叶松林土壤的固碳能力大于杉木人工林,从侧面也反映了同样作为亚热带地区的造林树种,日本落叶松林要优于杉木人工林。

Density and distribution of soil organic carbon of young and middle-aged Larix kaempferi forest in subtropics

In this paper,the characters of density and distribution of soil organic carbon in young and middle-aged Larix kaempferi forest in subtropics were analyzed based on the soil data of 32 sample plots.The results showed as follows,（1） The concentration and density of soil organic carbon in middle-aged forest were obviously higher than those in young forest.（2） The concentration and density of soil organic carbon in mixed forest were obviously higher than those in pure forest.（3） The density of soil organic carbon（SOC） in 0~80 cm layer was 172.25t/hm2,and SOC mainly concentrated in top layer within 0~20cm.The densities of SOC within 0~20cm layer were 175.21%,129.52% of that within 20~40cm,40~80cm layer respectively.In the same soil profile,the soil organic carbon density was decreasing with the increase of depth of soil.（4） The concentration and density of soil organic carbon of Larix kaempferi forest were obviously higher than those of 20-year-old Cunninghamia lanceolata plantation,which not only indicated that the carbon fixation ability of Larix kaempferi forest was greater than that of Cunninghamia lanceolata plantation,but also implied that,from a distinctive aspect,Larix kaempferi was superior to Cunninghamia lanceolata as an afforestation species in subtropical areas.