Title of article :
Spatiotemporal complexity of patchy invasion in a predator-prey system with the Allee effect.
Author/Authors :
Morozov، نويسنده , , Andrew and Petrovskii، نويسنده , , SERGEI and LI، نويسنده , , Bai-Lian، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
18
From page :
18
To page :
35
Abstract :
Invasion of an exotic species initiated by its local introduction is considered subject to predator–prey interactions and the Allee effect when the prey growth becomes negative for small values of the prey density. Mathematically, the system dynamics is described by two nonlinear diffusion–reaction equations in two spatial dimensions. Regimes of invasion are studied by means of extensive numerical simulations. We show that, in this system, along with well-known scenarios of species spread via propagation of continuous population fronts, there exists an essentially different invasion regime which we call a patchy invasion. In this regime, the species spreads over space via irregular motion and interaction of separate population patches without formation of any continuous front, the population density between the patches being nearly zero. We show that this type of the system dynamics corresponds to spatiotemporal chaos and calculate the dominant Lyapunov exponent. We then show that, surprisingly, in the regime of patchy invasion the spatially average prey density appears to be below the survival threshold. We also show that a variation of parameters can destroy this regime and either restore the usual invasion scenario via propagation of continuous fronts or brings the species to extinction; thus, the patchy spread can be qualified as the invasion at the edge of extinction. Finally, we discuss the implications of this phenomenon for invasive species management and control.
Keywords :
spatiotemporal chaos , Biological invasion , Predator–prey system , Patchy spread , Allee effect
Journal title :
Journal of Theoretical Biology
Serial Year :
2006
Journal title :
Journal of Theoretical Biology
Record number :
1537323
Link To Document :
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