黄土丘陵区人工林土壤有机碳的垂直分布特征

Vertical Distribution Characteristic of Soil Organic Carbon of Plantation in Hilly Loess Region

对黄土丘陵区刺槐和油松人工林的根系生物量、土壤有机碳含量及其土壤全氮进行了测定，分析了土壤有机碳和根系的垂直分布特征。结果表明，刺槐和油松人工林之间以及同一林分的不同林龄之间，根系生物量有明显差异。2种人工林表层土中有机碳含量不同，差值为0．4709，6，10-20cm土层有稍微差异，差值为0．075％，其他各层差别不明显，差值均小于0．023％。在不同林龄之间，除20cm以上土层，幼林和成林之间的土壤有机碳含量有差异外，其他各层几乎没有差异。说明土壤有机碳的积累受诸多因素的影响，根系对土壤碳的积累有一定影响，但影响程度不大。人工林土壤全氮与土壤有机碳含量之间呈显著的线性正相关。

In hilly loess region, we had determined the soil organic carbon and root biomass and soil total nitrogen of the plantation, analyzed the vertical distribution characteristics of soil organic carbon and root. The results indicated that the root biomass were distinct different between Robinia plantation and Pinus plantation, however, except 0-10 cm soil layer, the soil organic carbon contents were different, the value of difference was 0. 470% slightly different in 10-20 cm layer, the value of difference was only 0. 075%, hardly different in other soil layers, the difference value was less than 0. 023%. The root biomass were distinct different between old forest and young forest too, but the soil organic carbon contents were only different in 0-20 cm soil layer. Almost the same in other layers. The contents of total nitrogen had a significant positive relationship with the soil organic carbon.