Wang Yong-Qiang, Zhu Shi-Dan, Wang Han, Cao Kun-Fang, Wang Hong-Xiang
Guangxi Key Laboratory of Forest Ecology and Conservation, Key Laboratory of National Forestry and Grassland Administration on Cultivation of Fast-Growing Timber in Central South China, College of Forestry Guangxi University Nanning China.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangxi University Nanning China.
Ecol Evol. 2025 Sep 15;15(9):e72169. doi: 10.1002/ece3.72169. eCollection 2025 Sep.
Trait-based approaches offer an essential tool for exploring tree growth and adaptation strategies. However, the generality of trait-growth relationships and the role of tree size in influencing their relationships remain uncertain. This study aims to explore size-dependent trait variation and its effects on individual growth models using a trait-based approach. We measured the leaf anatomical characteristics and nutrient content of 322 trees from 18 coexisting species and monitored their growth rates in a subtropical montane cloud forest. Our results showed that between 26% and 62% of trait variance was attributed to intraspecific variation of different sized trees. Larger trees tend to have smaller specific leaf area (SLA) and thicker palisade tissue (PT), while they also exhibit smaller and denser stomata to optimize water utilization and photosynthetic efficiency. As trees increased in size, their basal area growth advantage was attributed to both vertical competitive advantage and functional trait adaptations for light capture. Canopy species enhanced individual tree growth by adjusting the morphological structures of their leaves, such as thicker PT, higher stomatal density, and lower SLA, while understory species increased leaf phosphorus content, reflecting their specialized adaptation strategies to distinct vertical niches in phosphorus-limited environments. In addition, traits measured at the individual level revealed broader trait-growth relationships compared to species average traits. The study highlights that the pronounced effects of size-dependent trait variation are crucial for elucidating trait-growth relationships and understanding tree adaptive strategies under heterogeneous vertical light conditions.
基于性状的方法为探索树木生长和适应策略提供了一个重要工具。然而，性状与生长关系的普遍性以及树木大小在影响这些关系中的作用仍不明确。本研究旨在使用基于性状的方法探索与大小相关的性状变异及其对个体生长模型的影响。我们测量了来自18个共存物种的322棵树的叶片解剖特征和养分含量，并监测了它们在亚热带山地云雾林中的生长速率。我们的结果表明，26%至62%的性状变异归因于不同大小树木的种内变异。较大的树木往往具有较小的比叶面积（SLA）和较厚的栅栏组织（PT），同时它们还表现出更小、更密集的气孔，以优化水分利用和光合效率。随着树木大小的增加，它们的断面积生长优势归因于垂直竞争优势和对光捕获的功能性状适应。冠层物种通过调整叶片的形态结构来促进个体树木生长，如更厚的PT、更高的气孔密度和更低的SLA，而林下物种则增加叶片磷含量，这反映了它们在磷限制环境中对不同垂直生态位的特殊适应策略。此外，与物种平均性状相比，在个体水平上测量的性状揭示了更广泛的性状与生长关系。该研究强调，与大小相关的性状变异的显著影响对于阐明性状与生长关系以及理解异质垂直光照条件下树木的适应策略至关重要。
