不同年龄榧树碳氮磷生态化学计量特征

Ecological Stoichiometry of Carbon,Nitrogen and Phosphorus in Torreya Grandis at Different Ages

研究不同年龄雌雄榧树各器官的碳(C)氮(N)磷(P)含量及其化学计量特征,为榧树人工林的科学经营管理提供理论支持。以安徽休宁县人工栽培的榧树(80a、200a、500a)为研究对象,通过采集榧树根、枝、叶的植物样品,分析不同年龄雌雄榧树各器官C、N、P含量及其化学计量变化特征。结果表明:雌雄榧树C、N、P含量及其化学计量存在差异。随年龄增加,雌榧树根和叶C含量增大,N、P含量下降,雄株根P含量上升,其他无显著变化;同龄中,雄榧树与雌榧树器官的C、N、P含量及化学计量特征存在差异,其中各器官的C含量雌株均显著大于雄株,雌榧树根N含量显著小于雄榧树,雌榧树根和枝P含量显著大于雄株,而雌榧树叶P含量显著小于雄株。整体上雌榧树C∶N和C∶P高于雄榧树;榧树不同器官C、N、P含量变化趋势基本一致,C、N含量表现为叶>枝>根,其中叶N含量显著高于根和枝,P含量为枝>根>叶,其中枝P含量显著高于根和叶,整体表现为C:N比为根>枝>叶,C:P和N:P表现为叶>根>枝;榧树叶N:P均值为25.58,榧树生长受P元素限制,且随年龄增加,P限制增加。本研究表明不同年龄雌雄榧树各器官C、N、P化学计量存在差异性,且相互关系密切。在榧树人工林土壤管理中,适当考虑雌雄差异,雌榧树随年龄增加应加大磷肥量。

The contents of carbon(C),nitrogen(N),phosphorus(P)and their stoichiometric characteristics of male and female Torreya grandis at different ages were studied to provide theoretical support for the scientific management of Torreya grandis plantation.Taking the artificially cultivated Torreya grandis(80a,200a and 500a)in Xiuning County,Anhui Province as the research object,the contents of C,N and P in various organs of male and female Torreya grandis at different ages and their stoichiometric changes were analyzed by collecting plant samples of their roots,branches and leaves.The results show that the contents of C,N and P and their stoichiometry are different between male and female Torreya grandis.With the increase of age,the content of C in roots and leaves of Torreya grandis increases;the content of N and P decreases;the content of phosphorus and P in roots of male plants increases.But there is no significant change in other aspects.At the same age,there are differences in C,N and P contents and stoichiometric characteristics between male and female Torreya grandis.The C content of each organ of female plant is significantly higher than that of male plant;the N content of female Torreya grandis root is significantly lower than that of male Torreya grandis,and the P content of female Torreya grandis root and branch is significantly higher than that of male plant.The P content of leaves of female Torreya grandis is significantly lower than that of male plants.On the whole,the C:N and C:P ratios of female Torreya grandis are higher than those of male Torreya grandis;the change trend of C,N and P content in different organs of Torreya grandis is basically the same.The content of C and N is leaf>branch>root,in which the content of N in leaf is significantly higher than that in root and branch,and the content of P in branch is branch>root>leaf,in which the content of P in branch is significantly higher than that in root and leaf.The overall performance of C:N ratio is root>branch>leaf,and the ratio of C:P and N:P is leaf>root>branch;the average N:P ratio of Torreya grandis leaves is 25.58.The growth of Torreya grandis is limited by P element,and the P limit increases with age.This study shows that there are differences in the stoichiometry of C,N and P in different organs of male and female Torreya grandis at different ages,and they are closely related to each other.In the soil management of Torreya grandis plantation,the differences between the male and female should be properly considered,and the amount of phosphorus fertilizer should be increased with the increase of age.