首页 > 分享 > 不同林龄榧树根、枝、叶的C、N、P化学计量及内稳性特征

不同林龄榧树根、枝、叶的C、N、P化学计量及内稳性特征

花匠小妙招
2025-02-08 21:08

摘要： 目的了解不同林龄榧树根、枝、叶的生态化学计量特征和内稳性特征的变化情况,为榧树的科学管理和保护提供基础数据。方法以浙江省诸暨市香榧国家森林公园0~100、≥100~300、≥300~500和≥500 a共4个林龄段的实生榧树为研究对象,通过野外采集榧树植株样品(根、枝、叶)和0~20 cm层土壤样品,分析不同林龄榧树根、枝、叶的碳(C)、氮(N)、磷(P)含量及其化学计量特征变化和榧树内稳性特征。结果不同林龄榧树C、N、P含量及化学计量特征均无显著差异,根、枝、叶的C、N、P含量均以≥300~500 a的榧树表现最高,枝和叶的C、N含量以≥500 a的榧树最低,而根P含量以≥100~300 a的最低;不同林龄榧树叶的N/P(N、P质量比)均小于N限制的阈值(14);榧树根、枝、叶的C、N、P含量存在一定的变化趋势,整体上表现为叶>枝>根,叶和枝的C、P含量显著高于根的,叶N含量显著高于根和枝的,各器官N和P含量均为正相关关系,且枝中N、P相关性达到极显著水平(P <0.01);榧树根、枝、叶的化学计量特征存在差异,根和枝的C/N(C、N质量比)显著高于叶的,根的C/P(C、P质量比)显著高于枝、叶的; 内稳性指数HN/P(20.00)>HP(11.76),即内稳性以N/P大于P。结论榧树C、N、P化学计量特征随林龄增长未表现出差异,而榧树根、枝、叶的C、N、P含量及化学计量特征存在差异,并且榧树整个生长过程中均受到N素的限制,需要合理施N肥来促进榧树的生长。

关键词: 榧树, 林龄, 根, 枝, 叶, 化学计量, 化学计量内稳性

Abstract:

【Objective】 The objective of this study is to investigate C, N and P stoichiometric characteristics and stoichiometric homoeostasis of Torreya grandis.【Method】 The T. grandis of different ages (0-100, ≥100-300, ≥300-500 and ≥500 a) were selected from Zhuji National Forest Park of Zhejiang Province. The plant samples (roots, branches and leaves) and 0-20 cm soil samples of T. grandis of different ages were collected from the field to analyze the C, N and P stoichiometric characteristics and stoichiometric homoeostasis.【Result】 There were no significant differences in C, N and P concentrations and stoichiometric characteristics of T. grandis of different ages. The concentrations of C, N and P were the highest in ≥300-500 a, and the concentrations of C and N in branches and leaves were the lowest in ≥500 a, while the concentrations of P in roots were the lowest in ≥100-300 a, and the N/P of leaves of different ages was lower than the threshold of N limitation of 14. The concentrations of C, N and P in different organs showed the same trend: leaf > branch > root. The concentrations of C and P in leaves and branches were significantly higher than those in roots, and the concentrations of N in leaves were significantly higher than those in roots and branches. Overall, the concentrations of N and P in all organs showed a positive relationship, and were significantly correlated in branches (P<0.01). Further, there were significant differences in the stoichiometric characteristics of different organs of T. grandis. The C/N ratios of roots and branches were significantly higher than those of leaves, the C/P ratio of roots was significantly higher than those of branches and leaves, and stoichiometric homoeostasis of P (HP) and (HN/P) was found in T. grandis. In addition, The N/P ratio (HN/P =20.00) had a higher degree of stoichiometric homoeostasis than P concentration (HP =11.76). 【Conclusion】 The C, N, P ratios of T. grandis did not differ with age, but those of organs did. The growth of T. grandis was mostly limited by soil N, therefore, fertilization may thus promote the growth of T. grandis at all growing stages.

Key words: Torreya grandis forest, age, root, branch, leaf, stoichiometry, stoichiometric homoeostasis

中图分类号:

S718