Variation in leaf morphological, stomatal, and anatomical traits and their relationships in temperate and subtropical forests

Congcong Liu,Li Xu,Zhi Chen,Nianpeng He,Ying Li

doi:10.1038/s41598-019-42335-2

Abstract

Leaf functional traits have attracted the attention of ecologists for several decades, but few studies have systematically assessed leaf morphological traits (termed “economic traits”), stomatal (termed “hydraulic”), and anatomical traits of entire forest communities, thus it is unclear whether their relationships are consistent among trees, shrubs, and herbs, and which anatomical traits should be assigned to economical or hydraulic traits. In this study, we collected leaf samples of 106 plant species in temperate forests and 164 plant species in subtropical forests and determined nine key functional traits. We found that functional traits differed between temperate and subtropical forests. Leaf traits also differed between different plant functional groups, irrespective of forest type; dry matter content, stomatal density, and cell tense ratio followed the order trees > shrubs > herbs, whereas specific leaf area and sponginess ratio showed the opposite pattern. The correlations of leaf traits were not consistent among trees, shrubs, and herbs, which may reflect different adaptive strategies. Principal component analysis indicated that leaf economics and hydraulic traits were uncoupled in temperate and subtropical forests, and correlations of anatomical traits and economic and hydraulic traits were weak, indicating anatomical traits should be emphasized in future studies.

Highlights

Plant functional traits are commonly used as robust indicators of factors affecting the distribution of species, and they can be used to predict the responses of ecosystem structures and functions to global climate change[1]
Previous studies indicated that specific leaf area increased with decreasing light exposure[5,6], leaf thickness increased due to intense irradiance[7], the thickness of palisade tissue decreased and that of spongy tissue increased under weak lighting conditions[8], and higher maximum stomatal conductance may benefit species under low CO2 conditions and high irradiance or nutrient supply[9]
Et al.[10] and Cornwell and Ackerly[11] used leaf functional traits to predict how plant species co-exist within a community and to elucidate the drivers of community assembly. All of these studies were conducted on a small array of plant species or focused on only one or few leaf functional traits, and few studies combined leaf morphological, stomatal, and anatomical traits of an entire forest community

Summary

Introduction

Plant functional traits are commonly used as robust indicators of factors affecting the distribution of species, and they can be used to predict the responses of ecosystem structures and functions to global climate change[1]. Et al.[10] and Cornwell and Ackerly[11] used leaf functional traits to predict how plant species co-exist within a community and to elucidate the drivers of community assembly. All of these studies were conducted on a small array of plant species or focused on only one or few leaf functional traits, and few studies combined leaf morphological (referred to as “economical”), stomatal (referred to as “hydraulic”), and anatomical traits of an entire forest community. Relationships between leaf functional traits have been examined in different leaf types, phylogenetic groups, biomes, and even on a global scale. Shrubs, and herbs in different environments, under different lighting conditions, we hypothesized that relationships between leaf traits are not consistently stable in trees, shrubs, and herbs in forest communities

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Conclusion