Leaf Venation Architecture in Relation to Leaf Size Across Leaf Habits and Vein Types in Subtropical Woody Plants

Abstract

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.

Effect of leaf phenology and morphology on the coordination between stomatal and minor vein densities

“…For instance, a significant difference in stomatal density between evergreen and deciduous tree species was observed in a moist tropical forest in South Asia ( Rahman et al., 2022 ). In contrast, another study conducted within a subtropical forest community in China reported no discernible difference in minor vein density between evergreen and deciduous species ( Peng et al., 2022 ). Nevertheless, a limited number of studies have investigated the coordination between minor veins and stomatal densities in evergreen and deciduous tree species.…”

Quantitative MRI imaging of parenchyma and venation networks in Brassica napus leaves: effects of development and dehydration

“…The macroscopic traits of leaf architecture (e.g. vein topology, hierarchy) are usually studied using chemical clearing followed by leaf scanning [5][6][7], while mesophyll width and cell size are usually estimated from micrographs [1,7]. While both methods provide reliable information, they remain invasive and result in the loss of leaf material.…”

Leaf functional traits: Ecological and evolutionary implications

“…During the longterm evolution, plants have evolved a series of complicated mechanisms, including morphological, physiological, biochemical changes to combat against imbalance of water metabolism and oxidative damage induced by water stress. For instance, plants display remarkably diverse leaf shapes and sizes in nature , and there seems to be a tradeoff between the leaf support cost and photosynthetic returns (Ma et al, 2022;Peng et al, 2022). In addition, when exposed to water deficit, such as in arid and semiarid environment with poor resources, plants are usually with a lower leaf area because water losses and carbon gain processes are tightly coupled .…”