杉木人工林伐后2种恢复模式碳储量的比较

A Comparative Study on Carbon Storage in Chinese Fir Plantations with Two Restoration Approaches

[目的]为了探讨恢复模式对森林生态系统碳库的影响,[方法]利用定位研究方法,对比分析了湖南会同杉木人工林皆伐后2种恢复模式(自然恢复和人工恢复)20年时森林生态系统碳储量及其空间分布。[结果]表明:(1)自然恢复植被层碳储量明显大于人工恢复,自然恢复的乔木层碳储量比人工恢复的高22.56%。自然恢复的乔木层各器官碳储量的分配比为干﹥枝﹥根﹥叶﹥皮,而人工恢复为干﹥根﹥枝﹥皮﹥叶。林下植被层和凋落物层碳储量所占比例非常小,自然恢复的灌木层、草本层和凋落物层碳储量分别为人工恢复的3.99、5.94、1.14倍。(2)自然恢复的土壤层碳储量比人工恢复的小;自然恢复表层(0 10 cm)土壤碳含量和碳储量均比人工恢复的大,但其它土层则相反;2种恢复模式的土壤碳含量、碳储量均随土层深度的增加而减少,不同恢复土壤各层碳储量所占分配比差异明显。(3)自然恢复各组分碳储量为乔木层﹥土壤层﹥凋落物层﹥灌木层﹥草本层,而人工恢复为土壤层﹥乔木层﹥凋落物层﹥灌木层﹥草本层。[结论]自然恢复模式更有利于伐后林地植被层碳储量的恢复,而人工恢复模式更有利于伐后林地土壤层碳储量的恢复。从整个森林生态系统看,杉木人工林皆伐后林地自然恢复模式固碳能力高于人工恢复模式,恢复模式对碳储量在生态系统各组分的分配也产生了一些影响。

To explore the effect of restoration approach on carbon pool of forest ecosystem.[Method]By positioning research, the differences in carbon storage and its spatial distribution of Chinese fir plantations restored 20 years ago with two restoration approaches （natural restoration and artificial restoration） were compared in Huitong Experimental Station of Forest Ecology, Hu＇nan Province.[Result]（1） Compared with those treated by artificial restoration, the carbon storage treated by natural restoration was significantly higher in vegetation layer, specifically, 22.56% higher in tree layer. Treated by natural restoration, the distribution ratio of carbon storage in each organ showed in an order of stem 〉 branch 〉 root 〉 leaf 〉 bark, while that treated by artificial restoration showed in an order of stem 〉 root 〉 branch 〉 leaf 〉 bark. The proportion of carbon storage of vegetation layer under canopy and litter layer were very small. Still, the carbon storages of shrub layer, herb layer and litter layer by natural restoration were 3.99, 5.94 and 1.14 times that by artificial restoration, respectively. （2） The soil carbon storage in a Chinese fir plantation ecosystem restored 20 years ago treated by natural restoration was lower than that by artificial restoration. The soil carbon content and carbon storage in the surface layer （0-10 cm） by the natural restoration was higher than that by artificial restoration, while the other layers were opposite. By both restoration, the soil carbon content and soil carbon storage in the same unit （10 cm per layer） were all decreased with the increase of soil depth, and the distribution ratio of each layer was significantly different in terms of soil carbon content and soil carbon storage. （3） The carbon storage of the plantation ecosystem by natural restoration was in the order of tree layer 〉 soil layer 〉 litter layer 〉 shrub layer 〉 herb layer, and that under artificial restoration was in the order of soil layer 〉 tree layer 〉 litter layer 〉 shrub layer 〉 herb layer. [Conclusion]The natural restoration approach is more conducive to the restoration of carbon storage in the vegetation layer, while the artificial restoration approach is more conducive to the restoration of soil carbon storage.From the whole forest ecosystem,the carbon sequestration capacity of Chinese fir plantation ecosystem restored 20 years ago by natural restoration was higher than that by artificial restoration, restoration approach also have some impact on the distribution of carbon storage in ecosystem components.