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Consumer-Resource Dynamics: Quantity, Quality, and Allocation
BACKGROUND: The dominant paradigm for modeling the complexities of interacting populations and food webs is a system of coupled ordinary differential equations in which the state of each species, population, or functional trophic group is represented by an aggregated numbers-density or biomass-densi...
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Formato: | Texto |
Lenguaje: | English |
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Public Library of Science
2011
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024398/ https://www.ncbi.nlm.nih.gov/pubmed/21283752 http://dx.doi.org/10.1371/journal.pone.0014539 |
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author | Getz, Wayne M. Owen-Smith, Norman |
author_facet | Getz, Wayne M. Owen-Smith, Norman |
author_sort | Getz, Wayne M. |
collection | PubMed |
description | BACKGROUND: The dominant paradigm for modeling the complexities of interacting populations and food webs is a system of coupled ordinary differential equations in which the state of each species, population, or functional trophic group is represented by an aggregated numbers-density or biomass-density variable. Here, using the metaphysiological approach to model consumer-resource interactions, we formulate a two-state paradigm that represents each population or group in a food web in terms of both its quantity and quality. METHODOLOGY AND PRINCIPAL FINDINGS: The formulation includes an allocation function controlling the relative proportion of extracted resources to increasing quantity versus elevating quality. Since lower quality individuals senesce more rapidly than higher quality individuals, an optimal allocation proportion exists and we derive an expression for how this proportion depends on population parameters that determine the senescence rate, the per-capita mortality rate, and the effects of these rates on the dynamics of the quality variable. We demonstrate that oscillations do not arise in our model from quantity-quality interactions alone, but require consumer-resource interactions across trophic levels that can be stabilized through judicious resource allocation strategies. Analysis and simulations provide compelling arguments for the necessity of populations to evolve quality-related dynamics in the form of maternal effects, storage or other appropriate structures. They also indicate that resource allocation switching between investments in abundance versus quality provide a powerful mechanism for promoting the stability of consumer-resource interactions in seasonally forcing environments. CONCLUSIONS/SIGNIFICANCE: Our simulations show that physiological inefficiencies associated with this switching can be favored by selection due to the diminished exposure of inefficient consumers to strong oscillations associated with the well-known paradox of enrichment. Also our results demonstrate how allocation switching can explain observed growth patterns in experimental microbial cultures and discuss how our formulation can address questions that cannot be answered using the quantity-only paradigms that currently predominate. |
format | Text |
id | pubmed-3024398 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-30243982011-01-31 Consumer-Resource Dynamics: Quantity, Quality, and Allocation Getz, Wayne M. Owen-Smith, Norman PLoS One Research Article BACKGROUND: The dominant paradigm for modeling the complexities of interacting populations and food webs is a system of coupled ordinary differential equations in which the state of each species, population, or functional trophic group is represented by an aggregated numbers-density or biomass-density variable. Here, using the metaphysiological approach to model consumer-resource interactions, we formulate a two-state paradigm that represents each population or group in a food web in terms of both its quantity and quality. METHODOLOGY AND PRINCIPAL FINDINGS: The formulation includes an allocation function controlling the relative proportion of extracted resources to increasing quantity versus elevating quality. Since lower quality individuals senesce more rapidly than higher quality individuals, an optimal allocation proportion exists and we derive an expression for how this proportion depends on population parameters that determine the senescence rate, the per-capita mortality rate, and the effects of these rates on the dynamics of the quality variable. We demonstrate that oscillations do not arise in our model from quantity-quality interactions alone, but require consumer-resource interactions across trophic levels that can be stabilized through judicious resource allocation strategies. Analysis and simulations provide compelling arguments for the necessity of populations to evolve quality-related dynamics in the form of maternal effects, storage or other appropriate structures. They also indicate that resource allocation switching between investments in abundance versus quality provide a powerful mechanism for promoting the stability of consumer-resource interactions in seasonally forcing environments. CONCLUSIONS/SIGNIFICANCE: Our simulations show that physiological inefficiencies associated with this switching can be favored by selection due to the diminished exposure of inefficient consumers to strong oscillations associated with the well-known paradox of enrichment. Also our results demonstrate how allocation switching can explain observed growth patterns in experimental microbial cultures and discuss how our formulation can address questions that cannot be answered using the quantity-only paradigms that currently predominate. Public Library of Science 2011-01-20 /pmc/articles/PMC3024398/ /pubmed/21283752 http://dx.doi.org/10.1371/journal.pone.0014539 Text en Getz, Owen-Smith. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Getz, Wayne M. Owen-Smith, Norman Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title | Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title_full | Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title_fullStr | Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title_full_unstemmed | Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title_short | Consumer-Resource Dynamics: Quantity, Quality, and Allocation |
title_sort | consumer-resource dynamics: quantity, quality, and allocation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024398/ https://www.ncbi.nlm.nih.gov/pubmed/21283752 http://dx.doi.org/10.1371/journal.pone.0014539 |
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