四川人工林生态系统碳储量特征

利用森林资源清查资料和标准地实测数据估算了四川人工林生态系统的碳密度、碳储量及分配特征.结果表明:四川人工林生态系统平均碳密度为161.16 Mg C·hm^-2,各层碳密度从大到小排序为土壤层(141.64 Mg C·hm^-2)＞乔木层(17.95 Mg C·hm^-2)＞枯落物层(1.06 Mg C·hm^-2)＞灌草层(0.52 Mg C·hm^-2).四川人工林生态系统总碳储量为573.57 Tg C,其中乔木层、灌草层、枯落物层和土壤层分别为63.88、1.836、3.764和504.09 Tg C,分别占总碳量的11.14%、0.32%、0.66%和87.88%.不同人工林生态系统的碳储量和碳密度差异较大,分别介于1.21～99.44 Tg C和75.50～251.74 Mg C·hm^-2之间,其空间分配也表现为土壤层最大、灌草层最小.但四川省人工林生态系统乔木层碳密度较低,幼、中龄林分比重大,如果对现有人工林加以更好的管理,碳吸存潜力较大.从生态系统水平监测人工林生态系统的碳储量有助于提高森林碳吸存估算的精度.

Characteristics of carbon stock in artificial forest ecosystem in Sichuan Province of China.

By using forest inventory data in combination with plot measurement, the characteristics of carbon density, stock, and partitioning in artificial forest ecosystem in Sichuan Province of China were studied. The results showed that the carbon density in this forest ecosystem was averagely 161.16 Mg C·hm^-2, being ranked in the order of soil layer (141.64 Mg C·hm^-2)＞tree layer (17.95 Mg C·hm^-2)＞litter layer (1.06 Mg C·hm^-2)＞shrub layer (0.52 Mg C·hm^-2), and the total carbon stock was 573.57 Tg C, with 63.88 Tg C, 1.836 Tg C, 3.764 Tg C, and 504.09 Tg C, accounting for 11.14%, 0.32%, 0.66%, and 87.88% of the total in tree layer, shrub layer, litter layer, and soil layer, respectively. The carbon density and stock in different artificial forest ecosystems varied from 75.50 Mg C·hm^-2 to 251.74 Mg C·hm^-2 and from 1.21 Tg C to 99.44 Tg C, with the highest and lowest values observed in soil layer and shrub layer, respectively. Comparing with other regions in China, Sichuan Province had a lower carbon density in the tree layer of artificial forest ecosystem, due to the higher proportion of young and middle age forest stands, which implied that a proper management of artificial forest could increase the carbon sequestration in forest ecosystem of Sichuan. To monitor the carbon stock in artificial forest ecosystem at ecosystem level could be helpful to the improvement of the precision of forest carbon sequestration evaluation.