Emergence of diversity in a model ecosystem

TL;DR

This paper models an ecosystem with competing species and demonstrates how diversity emerges through phase transitions influenced by interaction networks and isolated meta-populations.

Contribution

It introduces a model ecosystem with fixed interaction networks and shows how diversity arises via phase transitions and meta-population patches.

Findings

Low introduction rates lead to bistability.

High diversity state emerges through phase transition.

Isolated meta-populations are crucial for high diversity.

Abstract

The biological requirements for an ecosystem to develop and maintain species diversity are in general unknown. Here we consider a model ecosystem of sessile and mutually excluding organisms competing for space [Mathiesen et al. Phys. Rev. Lett. 107, 188101 (2011)]. The competition is controlled by an interaction network with fixed links chosen by a Bernoulli process. New species are introduced in the system at a predefined rate. In the limit of small introduction rates, the system becomes bistable and can undergo a phase transition from a state of low diversity to high diversity. We suggest that patches of isolated meta-populations formed by the collapse of cyclic relations are essential for the transition to the state of high diversity.