Role of the Dominant Species on the Distributions of Neighbor Species in a Subtropical Forest

Shiguang Wei,Xuejun Ouyang,Honglin Cao,Lin Li,Wanhui Ye,Scott E Nielsen,Lingfeng Mao,Zhigao Wang,Juyu Lian

doi:10.3390/f11030352

Abstract

Understanding the role of dominant species in structuring the distribution of neighbor species is an important part of understanding community assembly, a central goal of ecology. Phylogenetic information helps resolve the multitude of processes driving community assembly and the importance of evolution in the assembly process. In this study, we classified species in a 20-ha subtropical forest in southern China into groups with different degrees of phylogenetic relatedness to the dominant species Castanopsis chinensis. Species surrounding individuals of C. chinensis were sampled in an equal area annulus at six spatial scales, counting the percent of relatives and comparing this to permutation tests of a null model and variance among species groups. The results demonstrated that dominant species affected their relatives depending on community successional stage. Theory would predict that competitive exclusion and density-dependence mechanisms should lead to neighbors that are more distant in phylogeny from C. chinensis. However, in mature forests distant relatives were subjected to competitive repulsion by C. chinensis, while environment filtering led to fewer distant species, regardless of scale. A variety of biological and non-biological factors appear to result in a U-shaped quantitative distribution determined by the dominant species C. chinensis. Scale effects also influenced the dominant species. As a dominant species, C. chinensis played an important role in structuring the species distributions and coexistence of neighbor species in a subtropical forest.

Highlights

Community assembly has been one of the major over-arching topics in community ecology with species distributions being fundamental to understanding community assembly [1]
C. chinensis demonstrated a scale-invariant relationship between phylogenetic distance of neighboring chinensis demonstrated a scale-invariant relationship between phylogenetic distance of neighboring trees and C. chinensis (Figure S1; Figure S2)
Based on data from all subplots, the relationship of phylogenetic distance of C. chinensis and the percent of neighbors within different annuli suggested phylogenetic distance of C. chinensis and the percent of neighbors within different annuli suggested that neighbors of C. chinensis were either more likely to be closely related or more distantly related

Summary

Introduction

Community assembly has been one of the major over-arching topics in community ecology with species distributions being fundamental to understanding community assembly [1]. Forests 2020, 11, 352 two processes are thought to be fundamental in shaping the spatial distributions of species in plant communities: niche and neutral processes [2]. Much prior research has examined how the distribution of species is the outcome of niche processes such as interactions between biological and ecological processes [3]. In contrast to niche processes, neutral processes suggest that plant communities can be modeled without regard for species identity resulting in random species distributions [4]. Recent studies suggest that both niche and neutral processes affect species distributions [5]. There are many studies examining processes and phenomena of community assembly assume species to be independent from one another. A species, especially a dominant species, may have directional and endogenous relationships with neighboring species and their distribution

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Results

Conclusion