不同龄组杉木人工林土壤有机碳贮量及分布特征

Storage and distribution of soil organic carbon in different age-group Chinese fir plantations

对比分析了福寿林场3个龄组杉木人工林0～60 cm土层内土壤碳贮量及其土层分布特征,结果表明：1）3个龄组杉木人工林土壤有机碳含量都表现出随土壤深度增加而逐渐减小的趋势,土层0～20 cm有机碳含量最高,为29.07～35.27 g·kg-1,是土层20～30 cm和土层30～45 cm的1～2倍和3～4倍,而土层（45～60cm）的有机碳含量最少,为5.03～6.68 g·kg-1。2）3个龄组的人工林0～60 cm土层内平均碳含量和碳贮量都表现出了随着年龄的变化先减少而增加的趋势,其平均碳含量的次序依次为成熟林（16.65 g·kg-1）＞幼龄林（14.78g·kg-1）＞中龄林（13.36 g·kg-1）;碳贮量大小顺序依次为成熟林（79.59 t·hm-2）＞幼龄林（64.78 t·hm-2）＞中龄林（64.74 t·hm-2）,3）在0～45 cm范围的土层内,3个龄组的杉木人工林的土壤碳贮量占土壤总碳贮量的百分比在86%～91%之间,说明杉木人工林土壤碳贮量主要集中在这个土层深度内。

A comparative investigation was made to study storage and distribution of soil organic carbon in Chinese fir plantation ecosystems of three age-group in 0 ～ 60 cm soil layer in Fushou Forest Farm. The results show that：（1） the profile SOC declined along with the soil depths increased in three age-group fir plantation, the storage of SOC in 0 ～ 20 cm soil layer was highest from 29.07 g·kg-1 to 35.27 g·kg-1, being from 1 to 2 times as much as those in 20 ～ 30 cm and from 3 to 4 times as much as those in 30 ～ 45 cm, respectively. However, the storage of SOC in 45 ～ 60 cm soil layer was lowest from 5.03 g·kg-1 to 6.68 g·kg-1.（2） the average storage of SOC in 0 ～ 60 cm soil layer and carbon density decreased first and increased afterwards, the average storage of SOC varied in the order of mature（16.65 g·kg-1） 〉 young（14.78 g·kg-1） 〉 middle-aged（13.36 g·kg-1） and the carbon density varied in the order of mature（79.59 t·hm-2）〉 young（64.78 t·hm-2） 〉 middle-aged（64.74 t·hm-2）.（3） the storage of SOC were from 86% to 91% of the total storage of SOC in 0 ～ 45 cm, the soil organic carbon mainly concentrated from 0 to 45 cm soil layer.