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Global dynamics in a stage-structured discrete-time population model with harvesting

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Detalhes bibliográficos
Resumo:The purpose of this paper is to analyze the effect of constant effort harvesting upon global dynamics of a discrete-time population model with juvenile and adult stages. We consider different scenarios, including adult-only mortality, juvenile-only mortality, and equal mortality of juveniles and adults. In addition to analytical study of equilibria of the system, we analyze global dynamics by means of an automated set-oriented rigorous numerical method. We obtain a comprehensive overview of the dynamics as the harvest rate and survival probability change. In particular, we determine the range of parameters for which the population abundance gets larger in spite of an increase in the harvest rate (so-called hydra effect), and for which subsequent increases in harvesting effort can magnify fluctuations in population abundance (destabilize it) and then stabilize it again (so-called bubble effect).
Autores principais:Liz, Eduardo
Outros Autores:Pilarczyk, Pawel
Assunto:Nonlinear difference equations Age structure Ricker map Constant effort harvesting Population abundance Hydra effect Bubble effect Equilibrium Stability Periodic orbit Synchronous orbit Oscillations Saddle-node configuration Global dynamics Morse decomposition Attractor Isolating neighborhood Rigorous numerics Set-oriented computations Interval arithmetic
Ano:2012
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso restrito
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:The purpose of this paper is to analyze the effect of constant effort harvesting upon global dynamics of a discrete-time population model with juvenile and adult stages. We consider different scenarios, including adult-only mortality, juvenile-only mortality, and equal mortality of juveniles and adults. In addition to analytical study of equilibria of the system, we analyze global dynamics by means of an automated set-oriented rigorous numerical method. We obtain a comprehensive overview of the dynamics as the harvest rate and survival probability change. In particular, we determine the range of parameters for which the population abundance gets larger in spite of an increase in the harvest rate (so-called hydra effect), and for which subsequent increases in harvesting effort can magnify fluctuations in population abundance (destabilize it) and then stabilize it again (so-called bubble effect).