We investigate spatially inhomogeneous versions of the stochasticLotka-Volterra model for predator-prey competition and coexistence by means ofMonte Carlo simulations on a two-dimensional lattice with periodic boundaryconditions. To study boundary effects for this paradigmatic population dynamicssystem, we employ a simulation domain split into two patches: Upon setting thepredation rates at two distinct values, one half of the system resides in anabsorbing state where only the prey survives, while the other half attains astable coexistence state wherein both species remain active. At the domainboundary, we observe a marked enhancement of the predator population density.The predator correlation length displays a minimum at the boundary, beforereaching its asymptotic constant value deep in the active region. The frequencyof the population oscillations appears only very weakly affected by theexistence of two distinct domains, in contrast to their attenuation rate, whichassumes its largest value there. We also observe that boundary effects becomeless prominent as the system is successively divided into subdomains in acheckerboard pattern, with two different reaction rates assigned to neighboringpatches. When the domain size becomes reduced to the scale of the correlationlength, the mean population densities attain values that are very similar tothose in a disordered system with randomly assigned reaction rates drawn from abimodal distribution.
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