Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system

1. Ecologists have identified two types of processes promoting species coexistence: stabilizing mechanisms (niche differentiation and related processes) that increase negative intraspecific interactions relative to negative interspecific interactions, and equalizing mechanisms (neutrality) that mini...

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Main Authors: Zhang, Q, Buckling, A, Godfray, C
Format: Journal article
Language:English
Published: 2009
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author Zhang, Q
Buckling, A
Godfray, C
author_facet Zhang, Q
Buckling, A
Godfray, C
author_sort Zhang, Q
collection OXFORD
description 1. Ecologists have identified two types of processes promoting species coexistence: stabilizing mechanisms (niche differentiation and related processes) that increase negative intraspecific interactions relative to negative interspecific interactions, and equalizing mechanisms (neutrality) that minimize the differences in species' demographic parameters. It has been theoretically and empirically shown that the two types of mechanisms can operate simultaneously; however, their relative importance remains unstudied although this is a key question in the synthesis of niche and neutral theories. 2. We experimentally quantified the relative importance of niche and neutral mechanisms in promoting phenotypic diversity in a model microbial system involving different phenotypes of the bacterium Pseudomonas fluorescens. Initially isogenic populations of the bacterium can diversify into a series of major and minor classes of phenotypes that can be treated as analogues of species. We estimated the relative population growth rate when rare of 32 phenotypes from six replicate microcosms. Each phenotype was assessed in a re-assembled microcosm in which the relative densities of all phenotypes remained the same except for the focal one which was reduced in frequency. A growth rate advantage when rare was considered evidence of non-neutral processes. 3. Approximately one-third of the phenotypes had a growth rate advantage when rare while the remaining two-thirds showed neutral or near-neutral dynamics. Furthermore, there was overall little evidence that productivity increased with phenotypic diversity. 4. Our results suggest that niche and neutral processes may simultaneously contribute to the maintenance of biodiversity, with the latter playing a more important role in our system, and that the operation of niche mechanisms does not necessarily lead to a positive biodiversity effect on ecosystem properties. © 2009 British Ecological Society.
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spelling oxford-uuid:eadca3a2-3e83-4f9f-b6d5-6960519378d82022-03-27T11:05:18ZQuantifying the relative importance of niches and neutrality for coexistence in a model microbial systemJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:eadca3a2-3e83-4f9f-b6d5-6960519378d8EnglishSymplectic Elements at Oxford2009Zhang, QBuckling, AGodfray, C1. Ecologists have identified two types of processes promoting species coexistence: stabilizing mechanisms (niche differentiation and related processes) that increase negative intraspecific interactions relative to negative interspecific interactions, and equalizing mechanisms (neutrality) that minimize the differences in species' demographic parameters. It has been theoretically and empirically shown that the two types of mechanisms can operate simultaneously; however, their relative importance remains unstudied although this is a key question in the synthesis of niche and neutral theories. 2. We experimentally quantified the relative importance of niche and neutral mechanisms in promoting phenotypic diversity in a model microbial system involving different phenotypes of the bacterium Pseudomonas fluorescens. Initially isogenic populations of the bacterium can diversify into a series of major and minor classes of phenotypes that can be treated as analogues of species. We estimated the relative population growth rate when rare of 32 phenotypes from six replicate microcosms. Each phenotype was assessed in a re-assembled microcosm in which the relative densities of all phenotypes remained the same except for the focal one which was reduced in frequency. A growth rate advantage when rare was considered evidence of non-neutral processes. 3. Approximately one-third of the phenotypes had a growth rate advantage when rare while the remaining two-thirds showed neutral or near-neutral dynamics. Furthermore, there was overall little evidence that productivity increased with phenotypic diversity. 4. Our results suggest that niche and neutral processes may simultaneously contribute to the maintenance of biodiversity, with the latter playing a more important role in our system, and that the operation of niche mechanisms does not necessarily lead to a positive biodiversity effect on ecosystem properties. © 2009 British Ecological Society.
spellingShingle Zhang, Q
Buckling, A
Godfray, C
Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title_full Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title_fullStr Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title_full_unstemmed Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title_short Quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
title_sort quantifying the relative importance of niches and neutrality for coexistence in a model microbial system
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