Strong Environmental Filtering Based on Hydraulic Traits Occurring in the Lower Water Availability of Temperate Forest Communities.

Jiale Zhao,Ying Cao,Yongfu Chai,Jiangang Zhu,Ming Yue,Yuhan Zhang,Jinshi Xu,Qiulong Yin,Peiliang Liu,Cunxia Li

doi:10.3389/fpls.2021.698878

Abstract

The trait-based approaches have made progress in understanding the community assembly process. Here, we explore the key traits that may shape community assembly patterns of the same community type but within different water availabilities. Natural Quercus wutaishanica forests were chosen as a suitable study system to test the difference between economic and hydraulic traits across water availability on the Loess Plateau (LP, drought region) and Qinling Mountains (QL, humid region) of China. A total of 75 plots were established separately in two sites, and 12 functional traits (seven hydraulic traits and five economic traits) of 167 species were studied. Community-weighted mean trait values and functional diversity indices were compared between the two sites. Canonical component analysis was performed to infer whether the changes of community traits and their relationships are driven by intraspecific variation or species turnover. Evidence for likely community assembly processes was tested using the null model to determine whether functional structure among seven hydraulic traits and five economic traits was dominated by different ecological processes between two sites. We found that forests in the Loess Plateau and Qinling Mountains showed different hydraulic and economic traits. Hydraulic and economic traits coupled at the community level were driven by species turnover. Hydraulic traits showed more significant convergent patterns on LP than that in QL. Our results suggest a strong environmental filtering process occurred in hydraulic-based community assembly in the temperate forest with low water availability. Reveal the relationship of hydraulic and economic traits at the community level. Emphasize the critical role of multi-dimensional traits selecting like hydraulic traits in community ecology.

Highlights

Community assembly is one of the essential topics in ecology, helping to explain researchers understanding species coexistence and distribution (Ellner et al, 2019)
(2) Economic and hydraulic traits are strongly coordinated at the community level
tissue density (TD) showed no significant differences between the Loess Plateau (LP) and Qinling Mountains (QL) (Figure 2D)

Summary

Introduction

Community assembly is one of the essential topics in ecology, helping to explain researchers understanding species coexistence and distribution (Ellner et al, 2019). Because of the direct link between traits and the plant organism’s function, trait strcucture patterns provide significant insights into how communities are assembled (HilleRisLambers et al, 2012; Kunstler et al, 2016; Loranger et al, 2016). As a link between species and the environment (Lamanna et al, 2014), functional traits are a new perspective to study complex ecological processes. Those related to water transport and CO2 exchange have received more attention, reflecting the crucial importance of processes in the biosphere’s functioning (Li S. et al, 2015). Certain other groups of traits, indicating a balance between the demand and supply of water, form the hydraulic traits (Zhang et al, 2012; Sack and Scoffoni, 2013; Li L. et al, 2015; Yin et al, 2018)

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Discussion

Conclusion