水保所知识产出(1956---)知识库

为阐明不同人工林生态系统间生态化学计量特征的差异，采用野外采样与室内分析相结合的方式分析了陕北黄土丘陵区
落叶阔叶树种刺槐和常绿针叶树种油松人工林乔木、灌草、枯落物和土壤(土层深度 0—100cm)C、N、P 化学计量特征。结果表
明:1)刺槐乔木各器官(叶、枝、干、皮、根)C 含量显著低于油松，但 N 和 P 含量显著高于油松。因此，油松的 C ∶N 和 C ∶P 显著
大于刺槐，而 N ∶P 小于刺槐。2)刺槐林下枯落物 N 和 P 含量显著高于油松，但 C 含量显著小于油松。此外，油松林下枯落物
C ∶N(70．21)大于刺槐林下枯落物 C ∶N(19．71)，说明油松林下枯落物分解较慢，有利于养分的存储。3)刺槐和油松人工林土壤
C、N 含量均随土壤深度增加而减少，P 含量则基本保持不变。刺槐人工林土壤中 C 含量低于油松，N、P 含量在两者之间无显著
差异。4)刺槐人工林内乔灌草叶、枯落物与土壤 C、N、P 及其计量比的相关性多集中在 10—20、20—30cm 土层，而油松林中各
组分与土壤营养元素的相关性相对较小，其中 20—30cm 土层中无显著相关性，说明相比刺槐人工林而言，油松人工林内土壤层
N、P 供应量对植物叶片 N、P 含量影响不显著。本研究为深入了解黄土丘陵区生态系统养分耦合循环机制奠定了基础，同时也
为黄土丘陵区的植被恢复工作提供了一定的指导意义。

 To comprehensively understand the stoichiometric characteristics of different plantation ecosystems，field
investigations and laboratory analyses were performed to study the carbon (C)，nitrogen (N)，and phosphorus (P)
stoichiometries in the arbor，shrub，herb，litter，and soil (soil depth 0—100cm) of the deciduous broad-leaved tree
species Ｒobinia pseudoacacia and evergreen coniferous tree species Pinus tabuliformis plantations in the Loess hilly-gully
region，northern Shaanxi，China． The results showed that 1) the C concentrations of arbor organs were significantly lower in
Ｒobinia than in the Pinus plantations，while the N and P concentrations were significantly higher in Ｒobinia than in the
Pinus plantations． Thus，the C ∶N and C ∶P ratios were significantly higher in Pinus than in the Ｒobinia plantations，but theN ∶P ratio in Pinus was less than that in the Ｒobinia plantation． 2) The litter N and P concentrations were significantly
higher in Ｒobinia than in the Pinus plantations，but the C concentration was significantly lower in Ｒobinia than in the Pinus
plantations． In addition，the litter C ∶N ratio was higher in Pinus (70．21) than in the Ｒobinia (19．71) plantations． This
indicated that the lower decomposition rate of litter was advantageous to nutrient storage in the Pinus plantation． 3) The soil
C and N concentrations decreased with increasing soil depth，but the P concentrations remained constant in both plantations．
The soil C concentration in Ｒobinia was less than that in the Pinus plantation，but no difference was observed in N and P
concentrations． 4) The correlations between the C，N，P，and nutrient ratios of the arbor leaf，shrub leaf，herb leaf，litter，
and soil in the Ｒobinia plantation were more focused in the 10—20，and 20—30cm soil layers，and these correlations in the
Pinus plantation were relatively lower，with no significant correlation even in 20—30cm soil layer． This indicated that
compared with the Ｒobinia plantation，the supply of N and P had no significant impact on the N and P content of leaf in the
Pinus plantation． This study establishes the foundation for illuminating the ecosystem nutrient coupling mechanism in Loess
hilly-gully region，as well as provides a guiding significance for the vegetation restoration in the Loess hilly-gully region．