Changes in the gradient percolation transition caused by an Allee effect
Autor: | Gastner, Michael T., Oborny, Beata, Ryabov, Alexey B., Blasius, Bernd |
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Rok vydání: | 2010 |
Předmět: | |
Zdroj: | Phys. Rev. Lett. 106, 128103 (2011) |
Druh dokumentu: | Working Paper |
DOI: | 10.1103/PhysRevLett.106.128103 |
Popis: | The establishment and spreading of biological populations depends crucially on population growth at low densities. The Allee effect is a problem in those populations where the per-capita growth rate at low densities is reduced. We examine stochastic spatial models in which the reproduction rate changes across a gradient g so that the population undergoes a 2D-percolation transition. Without the Allee effect, the transition is continuous and the width w of the hull scales as in conventional (i.e., uncorrelated) gradient percolation, proportional to g^(-0.57). However, with a strong Allee effect the transition is first order and w is proportional to g^(-0.26). Comment: 4 pages, 4 figures, Phys. Rev. Lett., in print, supplementary material available at http://www2.imperial.ac.uk/~mgastner/publications/suppl_PRL_Jan11.pdf |
Databáze: | arXiv |
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