豫西黄土丘陵区不同林龄栎类和侧柏人工林碳、氮储量

Storage of carbon and nitrogen in Quercus and Platycladus orientalis plantations at different ages in the hilly area of western Henan Province,China

利用空间代替时间样地调查法,分析了豫西黄土丘陵区栎类和侧柏人工林生态系统碳、氮储量的分布格局,以及不同土层碳储量和氮储量随林龄的动态变化.结果表明:随着树龄的增加,两类人工林乔木层和枯落物层碳储量均增加,土壤碳储量和氮储量主要在表层(0~20 cm)汇聚,且各土层碳储量和氮储量随着林龄增加表现为减少-增加-减少的趋势.各林龄栎类人工林土壤表层碳、氮储量分别为20.31~50.07和1.68~2.12 t·hm^(-2);不同林龄侧柏人工林土壤表层碳、氮储量分别为23.99~48.76和1.59~2.34 t·hm^(-2);各林龄栎类和侧柏人工林生态系统的碳储量分别为52.04~275.82和62.18~279.81 t·hm^(-2);侧柏人工林碳汇能力略高于栎类人工林.土壤C/N随着造林年限的增加呈增加趋势.

In the study, the method of space substituting time was used to investigate the distribution pattern of carbon and nitrogen storages in Quercus and Platycladus orientalis plantation ecosystems at different ages in hilly area of western Henan Province, China. We also analyzed the dynamic changes of soil carbon and nitrogen storages in different soil layers in the two plantation ecosystems. The results showed that the carbon storage in the arbor and litter layers increased with the increasing tree age. The storage of carbon and nitrogen in soil aggregated mainly in the surface layer and showed a trend of decrease-increase-decrease with the increasing tree age in all soil layers. The ranges of carbon and nitrogen storage in the surface soil were 20.31-50.07 and 1.68-2.12 t·hm-2 in Quercus plantation, and 23.99-48.76 and 1.59-2.34 t·hm-2 in P. orientalis plantation, respectively. Carbon storage ranges in Quercus and P. orientalis plantation ecosystems at different ages were 52.04-275.82 and 62.18-279.81 t·hm-2, respectively. The carbon sequestration capacity in P. orientalis plantation was a little higher than that in Quercus plantation. Soil C/N increased with the increase of afforestation age.