Local community assembly mechanisms shape soil bacterial \u03b2 diversity patterns along a latitudinal gradient

Xiao Zhang,Jingxin Wang,Zachary Freedman,Jamie Schuler,Kuan Liu,Hui Wang,Shirong Liu,Xiangzhen Li,Shenglei Fu,Minjie Yao,Xiaojing Liu,Yongtao Huang

doi:10.1038/s41467-020-19228-4

Abstract

Biodiversity patterns across geographical gradients could result from regional species pool and local community assembly mechanisms. However, little has been done to separate the effects of local ecological mechanisms from variation in the regional species pools on bacterial diversity patterns. In this study, we compare assembly mechanisms of soil bacterial communities in 660 plots from 11 regions along a latitudinal gradient in eastern China with highly divergent species pools. Our results show that β diversity does not co-vary with γ diversity, and local community assembly mechanisms appear to explain variation in β diversity patterns after correcting for variation in regional species pools. The variation in environmental conditions along the latitudinal gradient accounts for the variation in β diversity through mediating the strength of heterogeneous selection. In conclusion, our study clearly illustrates the importance of local community assembly processes in shaping geographical patterns of soil bacterial β diversity.

Highlights

Biodiversity patterns across geographical gradients could result from regional species pool and local community assembly mechanisms
Most previous studies focused on the influences of large scale assembly processes on biogeographical gradients in β diversity[1,4,13], yet few studies explored βdiversity patterns underpinned by local community assembly processes and regional species pools along latitudinal gradients
There is a clear need to distinguish the influence of local community assembly processes from regional species pool, and this will help to ascertain the mechanism underlying the geographical pattern of soil bacterial community

Summary

Introduction

Biodiversity patterns across geographical gradients could result from regional species pool and local community assembly mechanisms. Patterns of site-to-site variation in species composition, known as β diversity, describes the scaling relationship between local (α) and regional (γ) diversity, and provides fundamental insights into the processes that create and maintain biodiversity[14,15] This commonly studied pattern has been used to illuminate biogeographic distributions of both microorganisms and macroorganisms along environmental gradients[10,13]. A heterogeneous environment can influence community composition by selectively filtering species from the regional species pool in different ways across local communities, resulting in high β diversity[17]. There is a clear need to distinguish the influence of local community assembly processes from regional species pool, and this will help to ascertain the mechanism underlying the geographical pattern of soil bacterial community

Methods

Results

Conclusion