黄土高原毛白杨人工老龄林生态系统碳密度研究

Carbon Density in Forest Ecosystem of Old Populus tomentosa Plantation in Loess Plateau

为评价黄土高原毛白杨人工林的碳汇能力,以45a生的老龄毛白杨林地为研究对象,通过对3块林地和2块临近荒地生态系统不同层次有机碳密度的调查得出,45a的毛白杨人工林生态系统有机碳密度为16.775kg.m-2,与荒地对比总有机碳密度增加了113.75%,平均每年增长2.53%,林地各层次有机碳密度大小依次为土壤层>乔木层>枯落物层>草本层>灌木层,分别占总有机碳密度的70.63%、27.11%、2.07%、0.14%和0.05%,表明土壤层与乔木层为林地生态系统有机碳的主要来源。说明在毛白杨人工林造林后期有显著的碳增汇效应。

For the purpose of evaluating the carbon storage ability of Populus tomentosa in loess plat- eau, forty-five years old populus tomentosa plantations were taken as the research object and the or ganic carbon density （OCD） of different layer in three plots of plantations and two plots of nearby bar- ren land were determined. The results showed that the value of OCD in the ecosystem of forty-five years old artificial populus tomentosa was 16. 775 kg · m-2, indicating an annual increase of 2.53% and 113.75% increase over the control. Besides, the results indicated that the OCD in the layer of the soil was the highest, followed by the tree layer and the litter layer, shrub layer and herbaceous layer successively. The percentages that OCD of different layers account for total OCD of ecosystem were 70.63% .27.11%.2.07%.0.14% and O. 05% respectively, indicating the soil layer and tree layer are the two main sources of organic carbon storage in forest ecosystem and that there is a remarkable car- bon sink effects in the later period of Populus tomentosa plantations establishment.