From Metawebs to Realised Webs: A Framework for Ecological Network Representation under Global Change

Tanya Strydom, Alexander M Dunhill, Jennifer A Dunne, Timothée Poisot , Andrew P Beckerman

Ecological networks provide a critical framework for understanding the architecture of biodiversity and predicting ecosystem responses to environmental change. However, the application of network ecology is often hindered by a lack of clarity regarding the assumptions inherent in different network representations. Here, we present a hierarchical framework that distinguishes between ‘metawebs’ (representing the fundamental feasibility of interactions) and ‘realised webs’ (representing interactions expressed in specific spatiotemporal contexts). We contrast our conceptual approach with recent data-centric reviews, focusing instead on the theoretical gradients that govern network construction. We identify five core processes that drive the transition from potential to realised interactions: evolutionary compatibility and co-occurrence, which define the feasibility of links; and abundance, diet choice, and non-trophic interactions, which determine their realisation. Furthermore, we map these processes onto a methodological spectrum of network construction, distinguishing between inductive approaches (e.g., trait-matching and stochastic models) that infer structure from observation, and deductive approaches (e.g., neutral and optimal foraging models) that generate structure from mechanistic first principles. By making explicit the assumptions and scale-dependent processes underpinning these different representations, this framework clarifies the scope of inference possible with each approach, ultimately facilitating more robust predictions of biodiversity dynamics in the anthropocene.