Structured Model Conserving Biomass for the Size-spectrum Evolution in Aquatic Ecosystems

Fuente: arXiv
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Main Authors: Kanzler, Laura, Perthame, Benoit, Sarels, Benoit
Format: Preprint
Published: 2022
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author Kanzler, Laura
Perthame, Benoit
Sarels, Benoit
author_facet Kanzler, Laura
Perthame, Benoit
Sarels, Benoit
contents Mathematical modelling of the evolution of the size-spectrum dynamics in aquatic ecosystems was discovered to be a powerful tool to have a deeper insight into impacts of human- and environmental driven changes on the marine ecosystem. In this article we propose to investigate such dynamics by formulating and investigating a suitable model. The underlying process for these dynamics is given by predation events, causing both growth and death of individuals, while keeping the total biomass within the ecosystem constant. The main governing equation investigated is deterministic and non-local of quadratic type, coming from binary interactions. Predation is assumed to strongly depend on the ratio between a predator and its prey, which is distributed around a preferred feeding preference value. Existence of solutions is shown in dependence of the choice of the feeding preference function as well as the choice of the search exponent, a constant influencing the average volume in water an individual has to search until it finds prey. The equation admits a trivial steady state representing a died out ecosystem, as well as - depending on the parameterregime - steady states with gaps in the size spectrum, giving evidence to the well known cascade effect. The question of stability of these equilibria is considered, showing convergence to the trivial steady state in a certain range of parameters. These analytical observations are underlined by numerical simulations, with additionally exhibiting convergence to the non-trivial equilibrium for specific ranges of parameters.
format Preprint
id arxiv_https___arxiv_org_abs_2212_06465
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Structured Model Conserving Biomass for the Size-spectrum Evolution in Aquatic Ecosystems
Kanzler, Laura
Perthame, Benoit
Sarels, Benoit
Analysis of PDEs
92D40, 45K05, 92C15
Mathematical modelling of the evolution of the size-spectrum dynamics in aquatic ecosystems was discovered to be a powerful tool to have a deeper insight into impacts of human- and environmental driven changes on the marine ecosystem. In this article we propose to investigate such dynamics by formulating and investigating a suitable model. The underlying process for these dynamics is given by predation events, causing both growth and death of individuals, while keeping the total biomass within the ecosystem constant. The main governing equation investigated is deterministic and non-local of quadratic type, coming from binary interactions. Predation is assumed to strongly depend on the ratio between a predator and its prey, which is distributed around a preferred feeding preference value. Existence of solutions is shown in dependence of the choice of the feeding preference function as well as the choice of the search exponent, a constant influencing the average volume in water an individual has to search until it finds prey. The equation admits a trivial steady state representing a died out ecosystem, as well as - depending on the parameterregime - steady states with gaps in the size spectrum, giving evidence to the well known cascade effect. The question of stability of these equilibria is considered, showing convergence to the trivial steady state in a certain range of parameters. These analytical observations are underlined by numerical simulations, with additionally exhibiting convergence to the non-trivial equilibrium for specific ranges of parameters.
title Structured Model Conserving Biomass for the Size-spectrum Evolution in Aquatic Ecosystems
topic Analysis of PDEs
92D40, 45K05, 92C15
url https://arxiv.org/abs/2212.06465