Higher-order interactions in ecology can be hidden in plain sight

TL;DR

This paper demonstrates that higher-order ecological interactions can often be mistaken for pairwise interactions when analyzing abundance time series, highlighting challenges in accurately inferring ecological mechanisms.

Contribution

It reveals that higher-order Lotka-Volterra dynamics can be mimicked by pairwise models, emphasizing the need for additional data to correctly identify ecological interactions.

Findings

Higher-order interactions can be reproduced by pairwise models.

Time-series data alone may be insufficient to infer true interaction structures.

Identifiability issues can lead to misleading ecological interpretations.

Abstract

Higher-order interactions are increasingly recognized as a key component of ecological dynamics. However, we show that higher-order Lotka-Volterra dynamics can, in some scenarios, be accurately reproduced by effective pairwise models fitted to the same abundance time series. Consequently, higher-order interactions cannot, in general, be inferred from time-series data alone. We further identify a fundamental problem of mechanistic identifiability, whereby distinct interaction mechanisms generate nearly indistinguishable dynamics, potentially leading to accurate yet misleading ecological interpretations. Our results highlight the need to complement time-series data with additional ecological information to infer interaction structure reliably.