滨海沙地不同林分类型土壤养分含量及其化学计量特征

Soil nutrient content and stoichiometric characteristics of different forest types in coastal sandy lands

测定长乐滨海沙地尾巨桉、木麻黄、纹荚相思、肯氏相思和湿地松等5种典型人工林0～10、10～20、20～40、40～60 cm土层土壤全碳、全氮、全磷含量,并分析其化学计量特征。结果表明,长乐滨海沙地5种林型0～10 cm土层土壤全碳、全氮含量分别为1.50～3.26、0.12～0.24 g·kg-1,均显著高于10～60 cm土层,基本随土层深度的增加而逐渐减小;土壤全磷含量在不同土层之间差异不大。0～60 cm土层土壤全碳含量以纹荚相思林最高,湿地松林最低;全氮含量则表现为固氮树种大于非固氮树种;全磷含量在不同林型之间差异不明显。5种林型土壤C∶N、C∶P、N∶P基本随土层深度的增加而逐渐减小; 0～10 cm土层土壤C∶P和N∶P均显著高于其他土层; 4个土层相关性分析表明,土壤C∶N、C∶P、N∶P与全碳、全氮含量呈正相关,与全磷含量呈负相关。

The contents of total carbon,total nitrogen and total phosphorus in0-10,10-20,20-40,40-60cm soil layers of Eucalyptus urophylla×E.grandis,Casuarina equisetifolia,Acacia culacocarpa,A.cunninghamii Steud,and Pinus elliottii Engelm five typical artificial forests on coastal sandy lands were determined,and their stoichiometric characteristics were analyzed.The results showed that the contents of total carbon and total nitrogen in the0-10cm soil layers of the five forest types on Changle coastal sandy lands were1.50-3.26g·kg^-1and0.12-0.24g·kg^-1,respectively,which were significantly higher than those of the10-60cm soil layer,indicating that the soil total carbon and total nitrogen contents decreased gradually with the increase of soil depth.The soil total phosphorus content was not much different between different soil layers.The total carbon content of the0-60cm soil layer was the highest in A.culacocarpa,and the lowest was in P.elliottii Engelm.The total nitrogen content of nitrogen fixing tree species was larger than that of non-nitrogen-fixing tree species.The total phosphorus content was not significant different between different forest types.Soil C∶N,C∶P and N∶P also showed a gradual decrease trend with the increase of soil depth.C∶P and N∶P in the0-10cm soil layers of the five forest types were significantly higher than other soil layers.The correlation analysis of five forest types and four soil layers showed that C∶N,C∶P,N∶P were positively correlated with total carbon and total nitrogen,but were negatively correlated with total phosphorus content.