Cargando…

Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients

A core issue in microbial ecology is the need to elucidate the ecological processes and underlying mechanisms involved in microbial community assembly. However, the extent to which these mechanisms differ in importance based on traits of taxa with different niche breadth is poorly understood. Here,...

Descripción completa

Detalles Bibliográficos
Autores principales: Luo, Zhengming, Liu, Jinxian, Zhao, Pengyu, Jia, Tong, Li, Cui, Chai, Baofeng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6378303/
https://www.ncbi.nlm.nih.gov/pubmed/30804920
http://dx.doi.org/10.3389/fmicb.2019.00169
_version_ 1783395902016192512
author Luo, Zhengming
Liu, Jinxian
Zhao, Pengyu
Jia, Tong
Li, Cui
Chai, Baofeng
author_facet Luo, Zhengming
Liu, Jinxian
Zhao, Pengyu
Jia, Tong
Li, Cui
Chai, Baofeng
author_sort Luo, Zhengming
collection PubMed
description A core issue in microbial ecology is the need to elucidate the ecological processes and underlying mechanisms involved in microbial community assembly. However, the extent to which these mechanisms differ in importance based on traits of taxa with different niche breadth is poorly understood. Here, we used high-throughput sequencing to examine the relative importance of environmental selection and stochastic processes in shaping soil bacterial sub-communities with different niche breadth (including habitat generalists, specialists and other taxa) across elevational gradients on the subalpine slope of Mount Wutai, Northern China. Our findings suggested that the composition of soil bacterial communities differed significantly different among elevational gradients. According to the niche breadth index, 10.9% of OTUs were defined as habitat generalists (B-value >8.7) and 10.0% of OTUs were defined as habitat specialists (B-value <1.5). Generalists and specialists differed distinctly in diversity and biogeographic patterns across elevational gradients. Environmental selection (deterministic processes) and spatial factors (stochastic processes) seemed to determine the assembly and biogeography of habitat generalists. However, for specialists, deterministic processes strongly influenced the distribution, while stochastic processes were not at play. Environmental drivers for generalists and specialists differed, as did their importance. Elevation, total nitrogen and pH were the main factors determining habitat generalists, and soil water content, nitrate nitrogen and pH had the strongest impacts on specialists. Moreover, variation partitioning analysis revealed that environmental selection had a much greater impact on both generalists (17.7% of pure variance was explained) and specialists (3.6%) than spatial factors. However, generalists had a much stronger response to spatial factors (2.3%) than specialists (0.3%). More importantly, null models of β-diversity suggested that specialists deviated significantly from non-neutral assembly mechanisms (relative null deviation= 0.64–0.74) relative to generalists (0.16–0.65) (P < 0.05). These results indicate that generalists and specialists are governed by different assembly mechanisms and present distinct biogeographical patterns. The large proportion of unexplained variation in specialists (93.3%) implies that very complex assembly mechanisms exist in the assembly of specialists across elevational gradients on the subalpine slope of Mount Wutai. It is essential to understand the microbial community assembly at a more refined level, and to expand the current understanding of microbial ecological mechanisms.
format Online
Article
Text
id pubmed-6378303
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-63783032019-02-25 Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients Luo, Zhengming Liu, Jinxian Zhao, Pengyu Jia, Tong Li, Cui Chai, Baofeng Front Microbiol Microbiology A core issue in microbial ecology is the need to elucidate the ecological processes and underlying mechanisms involved in microbial community assembly. However, the extent to which these mechanisms differ in importance based on traits of taxa with different niche breadth is poorly understood. Here, we used high-throughput sequencing to examine the relative importance of environmental selection and stochastic processes in shaping soil bacterial sub-communities with different niche breadth (including habitat generalists, specialists and other taxa) across elevational gradients on the subalpine slope of Mount Wutai, Northern China. Our findings suggested that the composition of soil bacterial communities differed significantly different among elevational gradients. According to the niche breadth index, 10.9% of OTUs were defined as habitat generalists (B-value >8.7) and 10.0% of OTUs were defined as habitat specialists (B-value <1.5). Generalists and specialists differed distinctly in diversity and biogeographic patterns across elevational gradients. Environmental selection (deterministic processes) and spatial factors (stochastic processes) seemed to determine the assembly and biogeography of habitat generalists. However, for specialists, deterministic processes strongly influenced the distribution, while stochastic processes were not at play. Environmental drivers for generalists and specialists differed, as did their importance. Elevation, total nitrogen and pH were the main factors determining habitat generalists, and soil water content, nitrate nitrogen and pH had the strongest impacts on specialists. Moreover, variation partitioning analysis revealed that environmental selection had a much greater impact on both generalists (17.7% of pure variance was explained) and specialists (3.6%) than spatial factors. However, generalists had a much stronger response to spatial factors (2.3%) than specialists (0.3%). More importantly, null models of β-diversity suggested that specialists deviated significantly from non-neutral assembly mechanisms (relative null deviation= 0.64–0.74) relative to generalists (0.16–0.65) (P < 0.05). These results indicate that generalists and specialists are governed by different assembly mechanisms and present distinct biogeographical patterns. The large proportion of unexplained variation in specialists (93.3%) implies that very complex assembly mechanisms exist in the assembly of specialists across elevational gradients on the subalpine slope of Mount Wutai. It is essential to understand the microbial community assembly at a more refined level, and to expand the current understanding of microbial ecological mechanisms. Frontiers Media S.A. 2019-02-11 /pmc/articles/PMC6378303/ /pubmed/30804920 http://dx.doi.org/10.3389/fmicb.2019.00169 Text en Copyright © 2019 Luo, Liu, Zhao, Jia, Li and Chai. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Luo, Zhengming
Liu, Jinxian
Zhao, Pengyu
Jia, Tong
Li, Cui
Chai, Baofeng
Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title_full Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title_fullStr Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title_full_unstemmed Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title_short Biogeographic Patterns and Assembly Mechanisms of Bacterial Communities Differ Between Habitat Generalists and Specialists Across Elevational Gradients
title_sort biogeographic patterns and assembly mechanisms of bacterial communities differ between habitat generalists and specialists across elevational gradients
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6378303/
https://www.ncbi.nlm.nih.gov/pubmed/30804920
http://dx.doi.org/10.3389/fmicb.2019.00169
work_keys_str_mv AT luozhengming biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients
AT liujinxian biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients
AT zhaopengyu biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients
AT jiatong biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients
AT licui biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients
AT chaibaofeng biogeographicpatternsandassemblymechanismsofbacterialcommunitiesdifferbetweenhabitatgeneralistsandspecialistsacrosselevationalgradients