# Divergences in Leaf Economic Traits Among Five Congeneric Tree Species in a Subtropical Forest

## TL;DR

This study explores how five related tree species in a Chinese karst forest differ in leaf traits, which may help explain how they coexist.

## Contribution

The study reveals divergence in leaf economic traits and habitat-mediated shifts among congeneric tree species in a subtropical karst forest.

## Key findings

- Leaf economic traits varied significantly among the five congeneric species.
- Species showed divergent habitat-mediated trait shifts along environmental gradients.
- Resource-use strategy differences may facilitate coexistence in the karst forest.

## Abstract

Exploring the differences in leaf economic traits between co‐occurring congeneric angiosperm species will advance the understandings of coexistence mechanisms of closely related species in sympatry. Here, we investigated the divergence in eight leaf economic traits and the underlying ecological drivers among 293 individual plants of five congeneric tree species of Carpinus (Betulaceae) that commonly co‐occur in a karst forest in southwestern China. We found there was generally a large proportion of trait variation that resided at the interspecific level, and these congeneric species commonly differed in leaf economic traits. We also found these congeneric species frequently exhibited divergent topographic habitat‐mediated trait shifts and displayed trait ranking reversals along the environmental gradients. However, these congeners did not differ in plant size‐dependent shifts of leaf economic traits. These findings imply the separation in resource‐use strategies among the congeneric species of Carpinus, which might contribute to resource niche partitioning and hence facilitate their coexistence in the karst forests.

Knowledge of how congeneric species co‐occur in a community differ in leaf economic traits, will advance the understandings of factors that contribute to the coexistence of closely related species in sympatry, especially in the karst forests of southwestern China that are generally rich in biodiversities. Here, we addressed this question and found that separation in leaf economic traits, as well as divergence in habitat‐mediated shifts of leaf economic traits, commonly exist between five congeneric tree species belonging to a common genus Carpinus (Betulaceae) in the karst forest of Maolan Nature Reserve in southwestern China.