Nico Blüthgen & Michael Staab: A Critical Evaluation of Network Approaches for Studying Species Interactions

Two students in the project MultiTroph in the field in China

Authors: Nico Blüthgen, Michael Staab

Annual Review of Ecology, Evolution, and Systematics, Volume 55, 2024, https://doi.org/10.1146/annurev-ecolsys-102722-021904

Summary: Ecological networks of species interactions are popular and provide powerful analytical tools for understanding variation in community structure and ecosystem functioning. However, network analyses and commonly used metrics such as nestedness and connectance have also attracted criticism. One major concern is that observed patterns are misinterpreted as niche properties such as specialization, whereas they may instead merely reflect variation in sampling, abundance, and/or diversity. As a result, studies potentially draw flawed conclusions about ecological function, stability, or coextinction risks. This article highlights potential biases in analyzing and interpreting species-interaction networks and reviews the solutions available to overcome them.

Conclusion: The authors recommend the use of null models in network analysis that account for species abundances. They show why considering variation across species and networks is important for understanding species interactions and their consequences. Network analyses can advance knowledge on the principles of species interactions but only when judiciously applied.