Ecological Systems as Complex Systems: Challenges for an Emerging Science

TLDR

Complex systems science has advanced ecological understanding in areas such as food webs, patch dynamics, and population fluctuations through simple measures and local‑interaction models, yet its definitions of complexity often miss key ecological features—diversity, cross‑scale interactions, memory, and environmental variability—limiting its contribution. The study aims to highlight these features and call for further advances so that complex systems science can be widely applied to understand ecological dynamics. The authors identify and emphasize the key ecological complexity features—diversity, cross‑scale interactions, memory, and environmental variability—that challenge classical complex systems science.

Abstract

Complex systems science has contributed to our understanding of ecology in important areas such as food webs, patch dynamics and population fluctuations. This has been achieved through the use of simple measures that can capture the difference between order and disorder and simple models with local interactions that can generate surprising behaviour at larger scales. However, close examination reveals that commonly applied definitions of complexity fail to accommodate some key features of ecological systems, a fact that will limit the contribution of complex systems science to ecology. We highlight these features of ecological complexity—such as diversity, cross-scale interactions, memory and environmental variability—that continue to challenge classical complex systems science. Further advances in these areas will be necessary before complex systems science can be widely applied to understand the dynamics of ecological systems.