title: Allee effects and population spread in patchy landscapes.
abstract: Invasion of alien species is one of the major threats for natural community structures, potentially leading to high economic and environmental costs. In this work, we study through a reaction-diffusion model the dynamics of an invasion in a heterogeneous environment and in the presence of a strong Allee effect. We model space as an infinite landscape consisting of periodically alternating favourable and unfavourable patches. In addition, we consider that at the interface between patch types individuals may show preference for more favourable regions. Using homogenization techniques and a classical result for spread with Allee effect in homogeneous landscapes, we derive approximate expressions for the spread speed. When compared with numerical simulations, these expressions prove to be very accurate even beyond the expected small-scale heterogeneity limit of homogenization. We demonstrate how rates of spatial spread depend on demographic and movement parameters as well as on the landscape properties.
authors.affiliation: a Instituto de Física Teórica, Universidade Estadual Paulista , São Paulo , SP 01140-070 , Brazil.
authors.forename: Gabriel Andreguetto
authors.initials: GA
authors.lastname: Maciel
authors.forename: Frithjof
authors.initials: F
authors.lastname: Lutscher
mesh_terms: D003198:Computer Simulation; D017753:Ecosystem; D004777:Environment; D005843:Geography; D058865:Introduced Species; D008954:Models, Biological; D011156:Population Density; D011157:Population Dynamics
keywords: 35K57; 92D25; Allee effects; habitat heterogeneity; homogenization; individual movement behaviour; invasions