| Abstract: |
| We study the effects of advection along environmental gradients on a diffusive competition model of the Lotka-Volterra type in a spatially heterogeneous environment. It is assumed that while the two species are ecologically equivalent, they adopt different dispersal strategies. One species disperses randomly, and the other species follows a directed path along the environmental gradient in addition to the random diffusion. It is known that the species with advection survives against the competing species with random dispersal when the boundary of the habitat is assumed to be a reflecting barrier to the population. In particular, sufficiently rapid movement in the direction of a source is always beneficial. In this study, a lethal environment is assumed at the boundary of a habitat. We show that under the lethal boundary condition, movement up the gradient of a resource may be either beneficial or harmful to a given species depending on the properties of the resource function. Competitive exclusion and coexistence can occur depending on the situation of the environmental gradient and strength of advection. Simulations are presented based on our results in the 1-dimension case. |
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