Predicting collapse of complex ecological systems: Quantifying the stability–complexity continuum
Journal article, 2020

Dynamical shifts between the extremes of stability and collapse are hallmarks of ecological systems. These shifts are limited by and change with biodiversity, complexity, and the topology and hierarchy of interactions. Most ecological research has focused on identifying conditions for a system to shift from stability to any degree of instability—species abundances do not return to exact same values after perturbation. Real ecosystems likely have a continuum of shifting between stability and collapse that depends on the specifics of how the interactions are structured, as well as the type and degree of disturbance due to environmental change. Here we map boundaries for the extremes of strict stability and collapse. In between these boundaries, we find an intermediate regime that consists of single-species extinctions, which we call the extinction continuum. We also develop a metric that locates the position of the system within the extinction continuum—thus quantifying proximity to stability or collapse—in terms of ecologically measurable quantities such as growth rates and interaction strengths. Furthermore, we provide analytical and numerical techniques for estimating our new metric. We show that our metric does an excellent job of capturing the system’s behaviour in comparison with other existing methods—such as May’s stability criteria or critical slowdown. Our metric should thus enable deeper insights about how to classify real systems in terms of their overall dynamics and their limits of stability and collapse.

Lotka–Volterra dynamics

Resilience

Structural stability

Population dynamics

Interaction network

Complexity

Author

Susanne Pettersson

Chalmers, Space, Earth and Environment, Physical Resource Theory

Van M. Savage

University of California

Martin Nilsson Jacobi

Chalmers, Space, Earth and Environment, Physical Resource Theory

Journal of the Royal Society Interface

1742-5689 (ISSN) 1742-5662 (eISSN)

Vol. 17 166 20190391

Subject Categories

Environmental Sciences related to Agriculture and Land-use

Ecology

Control Engineering

DOI

10.1098/rsif.2019.0391

PubMed

32396810

More information

Latest update

7/1/2020 7