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Positive density dependence acting on mortality can help maintain species-rich communities

Conspecific negative density dependence is ubiquitous and has long been recognized as an important factor favoring the coexistence of competing species at local scale. By contrast, a positive density-dependent growth rate is thought to favor species exclusion by inhibiting the growth of less competi...

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Autor principal: Aubier, Thomas G
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7302881/
https://www.ncbi.nlm.nih.gov/pubmed/32553104
http://dx.doi.org/10.7554/eLife.57788
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author Aubier, Thomas G
author_facet Aubier, Thomas G
author_sort Aubier, Thomas G
collection PubMed
description Conspecific negative density dependence is ubiquitous and has long been recognized as an important factor favoring the coexistence of competing species at local scale. By contrast, a positive density-dependent growth rate is thought to favor species exclusion by inhibiting the growth of less competitive species. Yet, such conspecific positive density dependence often reduces extrinsic mortality (e.g. reduced predation), which favors species exclusion in the first place. Here, using a combination of analytical derivations and numerical simulations, I show that this form of positive density dependence can favor the existence of equilibrium points characterized by species coexistence. Those equilibria are not globally stable, but allow the maintenance of species-rich communities in multispecies simulations. Therefore, conspecific positive density dependence does not necessarily favor species exclusion. On the contrary, some forms of conspecific positive density dependence may even help maintain species richness in natural communities. These results should stimulate further investigations into the precise mechanisms underlying density dependence.
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spelling pubmed-73028812020-06-22 Positive density dependence acting on mortality can help maintain species-rich communities Aubier, Thomas G eLife Ecology Conspecific negative density dependence is ubiquitous and has long been recognized as an important factor favoring the coexistence of competing species at local scale. By contrast, a positive density-dependent growth rate is thought to favor species exclusion by inhibiting the growth of less competitive species. Yet, such conspecific positive density dependence often reduces extrinsic mortality (e.g. reduced predation), which favors species exclusion in the first place. Here, using a combination of analytical derivations and numerical simulations, I show that this form of positive density dependence can favor the existence of equilibrium points characterized by species coexistence. Those equilibria are not globally stable, but allow the maintenance of species-rich communities in multispecies simulations. Therefore, conspecific positive density dependence does not necessarily favor species exclusion. On the contrary, some forms of conspecific positive density dependence may even help maintain species richness in natural communities. These results should stimulate further investigations into the precise mechanisms underlying density dependence. eLife Sciences Publications, Ltd 2020-06-18 /pmc/articles/PMC7302881/ /pubmed/32553104 http://dx.doi.org/10.7554/eLife.57788 Text en © 2020, Aubier http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited.
spellingShingle Ecology
Aubier, Thomas G
Positive density dependence acting on mortality can help maintain species-rich communities
title Positive density dependence acting on mortality can help maintain species-rich communities
title_full Positive density dependence acting on mortality can help maintain species-rich communities
title_fullStr Positive density dependence acting on mortality can help maintain species-rich communities
title_full_unstemmed Positive density dependence acting on mortality can help maintain species-rich communities
title_short Positive density dependence acting on mortality can help maintain species-rich communities
title_sort positive density dependence acting on mortality can help maintain species-rich communities
topic Ecology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7302881/
https://www.ncbi.nlm.nih.gov/pubmed/32553104
http://dx.doi.org/10.7554/eLife.57788
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