Large ecosystems in transition: bifurcations and mass extinction

TL;DR

This paper introduces a novel multispecies population model with climate feedback mechanisms, revealing how abiotic factors can lead to ecosystem bifurcations and mass extinctions, including chaotic regimes.

Contribution

It is the first model to incorporate feedback between climate and population dynamics, accounting for self-limitation effects in multispecies ecosystems.

Findings

Ecosystems can coexist with many species under stable conditions.

Abiotic changes can cause catastrophic bifurcations leading to extinction.

Strong abiotic influences may induce chaotic ecosystem behavior.

Abstract

We propose a model of multispecies populations surviving on distributed resources. System dynamics are investigated under changes in abiotic factors such as the climate, as parameterized through environmental temperature. In particular, we introduce a feedback between species abundances and resources via abiotic factors. This model is apparently the first of its kind to include a feedback mechanism coupling climate and population dynamics. Moreover, we take into account self-limitation effects. The model explains the coexistence of many species, yet also displays the possibility of catastrophic bifurcations, where all species become extinct under the influence of abiotic factors. We show that as these factors change there are different regimes of ecosystem behavior, including a possibly chaotic regime when abiotic influences are sufficiently strong.