Peng Guoquan, Xiong Yingjie, Yin Mengqi, Wang Xiaolin, Zhou Wei, Cheng Zhenfeng, Zhang Yong-Jiang, Yang Dongmei
College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China.
School of Biology and Ecology, University of Maine, Orono, ME, United States.
Front Plant Sci. 2022 May 6;13:873036. doi: 10.3389/fpls.2022.873036. eCollection 2022.
Leaves are enormously diverse in their size and venation architecture, both of which are core determinants of plant adaptation to environments. Leaf size is an important determinant of leaf function and ecological strategy, while leaf venation, the main structure for support and transport, determines the growth, development, and performance of a leaf. The scaling relationship between venation architecture and leaf size has been explored, but the relationship within a community and its potential variations among species with different vein types and leaf habits have not been investigated. Here, we measured vein traits and leaf size across 39 broad-leaved woody species within a subtropical forest community in China and analyzed the scaling relationship using ordinary least squares and standard major axis method. Then, we compared our results with the global dataset. The major vein density, and the ratio of major (1° and 2°) to minor (3° and higher) vein density both geometrically declined with leaf size across different vein types and leaf habits. Further, palmate-veined species have higher major vein density and a higher ratio of major to minor vein density at the given leaf size than pinnate-veined species, while evergreen and deciduous species showed no difference. These robust trends were confirmed by reanalyzing the global dataset using the same major vein classification as ours. We also found a tradeoff between the cell wall mass per vein length of the major vein and the major vein density. These vein scaling relationships have important implications on the optimization of leaf size, niche differentiation of coexisting species, plant drought tolerance, and species distribution.
叶片在大小和叶脉结构方面具有极大的多样性，这两个因素都是植物适应环境的核心决定因素。叶片大小是叶片功能和生态策略的重要决定因素，而叶脉作为支撑和运输的主要结构，决定了叶片的生长、发育和性能。叶脉结构与叶片大小之间的缩放关系已得到探索，但群落内部的关系以及不同叶脉类型和叶习性的物种之间的潜在差异尚未得到研究。在这里，我们测量了中国一个亚热带森林群落中39种阔叶木本植物的叶脉特征和叶片大小，并使用普通最小二乘法和标准主轴法分析了缩放关系。然后，我们将我们的结果与全球数据集进行了比较。在不同的叶脉类型和叶习性中，主脉密度以及主脉（一级和二级）与细脉（三级及以上）密度之比均随叶片大小呈几何下降。此外，在给定叶片大小下，掌状叶脉物种比羽状叶脉物种具有更高的主脉密度和更高的主脉与细脉密度比，而常绿和落叶物种则没有差异。通过使用与我们相同的主脉分类重新分析全球数据集，证实了这些稳健的趋势。我们还发现主脉每单位长度的细胞壁质量与主脉密度之间存在权衡。这些叶脉缩放关系对叶片大小的优化、共存物种的生态位分化、植物耐旱性和物种分布具有重要意义。
