Issue
EPL
Volume 87, Number 2, July 2009
Article Number 28001
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/87/28001
Published online 28 July 2009
EPL, 87 (2009) 28001
DOI: 10.1209/0295-5075/87/28001

Non-neutral theory of biodiversity

G. Bianconi1, L. Ferretti2 and S. Franz3

1   The Abdus Salam International Center for Theoretical Physics - Strada Costiera 11,34014 Trieste, Italy, EU
2   Facultat de Veterinaria and IFAE, Universitat Autonoma de Barcelona - 08193 Bellaterra, Spain, EU
3   LPTMS, UMR 8626 CNRS et Université Paris-Sud, Bâtiment 100 - 91405 Orsay Cedex, France, EU

gbiancon@ictp.it

received 19 May 2009; accepted in final form 25 June 2009; published July 2009
published online 28 July 2009

Abstract
We present a non-neutral stochastic model for the dynamics taking place in a meta-community ecosystems in the presence of migration. The model provides a framework for describing the emergence of multiple ecological scenarios and behaves in two extreme limits either as the unified neutral theory of biodiversity or as the Bak-Sneppen model. Interestingly, the model shows a condensation phase transition where one species becomes the dominant one, the diversity in the ecosystems is strongly reduced and the ecosystem is non-stationary. This phase transition extends the principle of competitive exclusion to open ecosystems and might be relevant for the study of the impact of invasive species in native ecologies.

PACS
87.23.-n - Ecology and evolution.
89.75.-k - Complex systems.
89.75.Da - Systems obeying scaling laws.

© EPLA 2009