【专题：红豆属植物多样性保育研究】红豆树不同等级苗木生长与叶片功能性状关系研究

Relationship between growth of different grade seedlings and leaf functional traits of Ormosia hosiei

关键词:  红豆树，野外回归，苗木生长，叶片功能性状，内在水分利用效率

Key words:  Ormosia hosiei, reintroduction in the wild, seedling growth, leaf functional traits, intrinsic water use efficiency

摘要:

红豆树（Ormosia hosiei）野生资源逐渐枯竭且苗期生长缓慢，制约其野外迁地保护。该研究以迁地保护红豆树苗木为对象，基于地径和苗高分级，通过单因素方差分析不同等级苗木的生长及叶片功能性状，旨在丰富其研究资料，为进一步开展研究提供基础。结果表明：(1)红豆树苗木的生长为异速生长模式(P1.0 < 0.01)且优先纵向生长。(2)不同等级苗木之间的叶片功能性状指标叶面积、叶片厚度、碳含量、磷含量、稳定碳13同位素、内在水分利用效率、叶绿素相对含量值无明显差异，仅叶片N含量呈显著差异(P < 0.05)。叶片N:P < 14，表明红豆树生长初期易受N限制。(3)相关性分析结果表明，地径和内在水分利用效率之间呈极显著正相关关系(P < 0.01)，苗高和SPAD值之间显著正相关(P < 0.01)。叶片N含量和δ13C显著负相关关系(P < 0.01)。综上认为，在野外回归造林过程中，红豆树苗木表现出优先进行纵向生长的资源分配策略，同时伴随水分利用效率低的特点，鉴于其生长初期存在氮素限制问题，迁地保护管理中应加强氮肥管理。

Abstract:

The wild resources of Ormosia hosiei are increasingly being depleted, and its slow seedling-stage growth poses significant constraints on ex-situ conservation efforts in wild habitats. This study focused on ex-situ conserved seedlings of O. hosiei and established a grading system based on diameter at ground level (DGL) and seedling height (SH). Through one-way ANOVA, we systematically analyzed the growth performance and leaf functional traits of seedlings across different grades. The research aims to enrich the scientific dataset of O. hosiei and establish a fundamental basis for subsequent studies for its population restoration and ex-situ conservation technology optimization. The results were as follows: (1) Seedlings of O. hosiei exhibited allometric growth patterns (P?.? < 0.01), with preferential vertical growth. (2) Among different grade seedlings, leaf functional traits including leaf area, leaf thickness, carbon content, phosphorus content, stable carbon-13 isotope (δ13C), intrinsic water use efficiency (iWUE), and relative chlorophyll content (SPAD) showed no significant differences, except for leaf nitrogen (N) content (P < 0.05). The leaf N:P ratio < 14 suggested that O. hosiei is susceptible to N limitation during the early growth stage. (3) Correlation analysis revealed a highly significant positive correlation between DGL and iWUE (P < 0.01), as well as a significant positive correlation between SH and SPAD value (P < 0.01). However, there was significant negative correlation between leaf N content and δ13C (P < 0.01). Conclusively, during wild reintroduction planting, O. hosiei seedlings demonstrate a resource allocation strategy prioritizing vertical growth, coupled with suboptimal water use efficiency. Ex-situ conservation management should therefore emphasize enhanced nitrogen fertilization practices to address the nitrogen limitation identified in early growth stages.