<p>We analyze a discrete-time predator–prey model with density-dependent prey harvesting. Through analytical and numerical methods, we establish biologically feasible solution domains, characterize equilibria stability in the <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="62" /> </InlineMediaObject> <EquationSource Format="TEX">\((\mathcal {G}, \mathcal {E}, \alpha )\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mi mathvariant="script">G</mi> <mo>,</mo> <mi mathvariant="script">E</mi> <mo>,</mo> <mi>α</mi> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation>-space, and identify codimension-1 and codimension-2 bifurcations. Key findings reveal critical <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="30" /> </InlineMediaObject> <EquationSource Format="TEX">\(1\!:\!k\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>1</mn> <mspace width="-0.166667em" /> <mo>:</mo> <mspace width="-0.166667em" /> <mi>k</mi> </mrow> </math></EquationSource> </InlineEquation> resonances (<InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq3.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="72" /> </InlineMediaObject> <EquationSource Format="TEX">\(k = 2, 3, 4\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>k</mi> <mo>=</mo> <mn>2</mn> <mo>,</mo> <mn>3</mn> <mo>,</mo> <mn>4</mn> </mrow> </math></EquationSource> </InlineEquation>) where period-doubling and Neimark–Sacker manifolds intersect, acting as organizing centers for chaotic and multistable regimes. A paradoxical stabilization effect is observed: moderate harvesting suppresses chaos via inverse period-doubling cascades. We determine precise thresholds <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq4.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="33" /> </InlineMediaObject> <EquationSource Format="TEX">\(\mathcal {E}^{PD}\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi mathvariant="script">E</mi> </mrow> <mrow> <mi mathvariant="italic">PD</mi> </mrow> </msup> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq5.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">\(\mathcal {E}^{NS}\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi mathvariant="script">E</mi> </mrow> <mrow> <mi mathvariant="italic">NS</mi> </mrow> </msup> </math></EquationSource> </InlineEquation> that define sustainable harvesting boundaries. Increasing the harvesting effort <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11071_2025_11701_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\mathcal {E}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">E</mi> </math></EquationSource> </InlineEquation> induces stability-loss bifurcations that lead to chaotic dynamics; however, appropriately managed harvesting can stabilize oscillatory behavior. Population collapse occurs through three distinct pathways: abrupt collapse at 1:2 resonance, patchy extinction near 1:3 resonance, and delayed “echo collapse” associated with 1:4 resonance-each offering quantitative insight into conservation strategy and management.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Influence of Prey Harvesting on the Dynamics of a Prey–Predator System: Multi-Parameter Bifurcation Analysis

  • Mohamed Ahmidi,
  • Karima Mokni,
  • Mohamed Ch-Chaoui

摘要

We analyze a discrete-time predator–prey model with density-dependent prey harvesting. Through analytical and numerical methods, we establish biologically feasible solution domains, characterize equilibria stability in the \((\mathcal {G}, \mathcal {E}, \alpha )\) ( G , E , α ) -space, and identify codimension-1 and codimension-2 bifurcations. Key findings reveal critical \(1\!:\!k\) 1 : k resonances ( \(k = 2, 3, 4\) k = 2 , 3 , 4 ) where period-doubling and Neimark–Sacker manifolds intersect, acting as organizing centers for chaotic and multistable regimes. A paradoxical stabilization effect is observed: moderate harvesting suppresses chaos via inverse period-doubling cascades. We determine precise thresholds \(\mathcal {E}^{PD}\) E PD and \(\mathcal {E}^{NS}\) E NS that define sustainable harvesting boundaries. Increasing the harvesting effort \(\mathcal {E}\) E induces stability-loss bifurcations that lead to chaotic dynamics; however, appropriately managed harvesting can stabilize oscillatory behavior. Population collapse occurs through three distinct pathways: abrupt collapse at 1:2 resonance, patchy extinction near 1:3 resonance, and delayed “echo collapse” associated with 1:4 resonance-each offering quantitative insight into conservation strategy and management.