Intraspecific Trait Variation Dilutes Deterministic Processes in Community Assembly of Arid Shrubs across Multiple Scales

Jinshi Xu,Han Dang,Yongfu Chai,Xiao Liu,Yaoxin Guo,Tingting Tian,Maolin Lei,Jiaxin Quan,Ming Yue

doi:10.3390/d12120447

Abstract

Trait-based approaches present a promising avenue for improving our understanding of species coexistence and community assembly, while intraspecific trait variation (ITV) across different spatial scales is important in trait-based community assembly mechanisms, especially in extreme environments. In this study, we focused on the functional diversity and community assembly patterns of a desert community across different spatial scales and investigated whether ITV plays a significant role in community assembly processes in arid habitats. A 50 m × 50 m plot with different small quadrats was established in a typical desert community at the transition zone between the Tengger Desert and Loess Plateau in China. A total of 14 traits were selected to assess the trait-based functional diversity and assembly processes in the community. We found that functional diversity showed different patterns when considering ITV and related to different types of traits (chemical traits or morphological traits) and some soil factors (pH and nitrate nitrogen). Plant communities in this study showed stochastic distribution patterns and similar functional diversity patterns based on functional trait approaches, regardless of spatial scales. Also, the effect of ITV on community assembly did not show more effect with increasing scales. These results indicated that ITV diluted deterministic processes in community assembly across scales in arid habitats.

Highlights

Community assembly is the process that shapes the structure and composition of plant communities, which describes the mechanism of diversity maintenance in a community [1,2].Approaches based on functional traits have been widely used to demonstrate these assembly processes and diversity patterns [3,4,5,6,7,8]
We found that considering intraspecific trait variation (ITV) would result in higher functional beta diversity both in multiple-trait and some single-trait analyses than that in the analysis without ITV (Figure 3)
Our results indicated that ITV significantly affects functional diversity at any spatial scale, and considering ITV for every single trait does not lead to consistent results within plant communities

Summary

Introduction

Community assembly is the process that shapes the structure and composition of plant communities, which describes the mechanism of diversity maintenance in a community [1,2].Approaches based on functional traits have been widely used to demonstrate these assembly processes and diversity patterns [3,4,5,6,7,8]. Community assembly is the process that shapes the structure and composition of plant communities, which describes the mechanism of diversity maintenance in a community [1,2]. The dominant trait-based community assembly or diversity studies have focused largely on trait differences among species [9], but there has recently been renewed interest in the role of intraspecific trait variation (ITV, [9,10,11]), which is extensive in nature and plays a significant role in trait-based community ecology [10,11,12]. Plants often show strong intraspecific variation in functional traits, and this variation influences plant response to environmental filters and biotic interactions [13,14,15]. The role of ITV in community assembly is not well understood as well [16,17,18], but ITV has been proved to increase community coexistence and shape local to regional scale biodiversity [1]

Methods

Results

Discussion

Conclusion