Non-neutral theory of biodiversityG. 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
received 19 May 2009; accepted in final form 25 June 2009; published July 2009
published online 28 July 2009
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.
87.23.-n - Ecology and evolution.
89.75.-k - Complex systems.
89.75.Da - Systems obeying scaling laws.
© EPLA 2009