Non-neutral theory of biodiversity

TL;DR

This paper introduces a non-neutral stochastic model for meta-community ecosystems that captures diverse ecological scenarios, including a phase transition leading to dominance by a single species, relevant for understanding invasive species impacts.

Contribution

It develops a novel non-neutral model bridging neutral theory and Bak-Sneppen dynamics, revealing a phase transition affecting biodiversity and ecosystem stability.

Findings

Model exhibits a condensation phase transition with species dominance.

Ecosystem diversity decreases significantly during the transition.

The model extends competitive exclusion principles to open ecosystems.

Abstract

We present a non-neutral stochastic model for the dynamics taking place in a meta-community ecosystems in 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 extend the principle of competitive exclusion to open ecosystems and might be relevant for the study of the impact of invasive species in native ecologies.