The Multilayer Nature of Ecological Networks

TL;DR

This paper introduces multilayer network theory as a comprehensive framework to model and analyze complex ecological systems with multiple interaction types, spatial and temporal variations, and interconnected networks.

Contribution

It formally defines ecological multilayer networks, illustrates their application with data analyses, and discusses future challenges and opportunities in ecological research.

Findings

Multilayer networks effectively model ecological complexity.

Application to existing data demonstrates practical utility.

Framework reveals new insights into ecological system architecture.

Abstract

Although networks provide a powerful approach to study a large variety of ecological systems, their formulation does not typically account for multiple interaction types, interactions that vary in space and time, and interconnected systems such as networks of networks. The emergent field of `multilayer networks' provides a natural framework for extending analyses of ecological systems to include such multiple layers of complexity, as it specifically allows one to differentiate and model `intralayer' and `interlayer' connectivity. The framework provides a set of concepts and tools that can be adapted and applied to ecology, facilitating research on high-dimensional, heterogeneous systems in nature. Here, we formally define ecological multilayer networks based on a review of previous and related approaches, illustrate their application and potential with analyses of existing data, and discuss limitations, challenges, and future applications. The integration of multilayer network theory into ecology offers largely untapped potential to further address ecological complexity, to ultimately provide new theoretical and empirical insights into the architecture and dynamics of ecological systems.