Foreseeing the future of mutualistic communities beyond collapse.

J Jelle Lever,Rick Quax,Ingrid A Van De Leemput,Els Weinans,Jordi Bascompte,Vasilis Dakos,Marten Scheffer,Egbert H Van Nes,John Drake

doi:10.1111/ele.13401

Abstract

Changing conditions may lead to sudden shifts in the state of ecosystems when critical thresholds are passed. Some well‐studied drivers of such transitions lead to predictable outcomes such as a turbid lake or a degraded landscape. Many ecosystems are, however, complex systems of many interacting species. While detecting upcoming transitions in such systems is challenging, predicting what comes after a critical transition is terra incognita altogether. The problem is that complex ecosystems may shift to many different, alternative states. Whether an impending transition has minor, positive or catastrophic effects is thus unclear. Some systems may, however, behave more predictably than others. The dynamics of mutualistic communities can be expected to be relatively simple, because delayed negative feedbacks leading to oscillatory or other complex dynamics are weak. Here, we address the question of whether this relative simplicity allows us to foresee a community's future state. As a case study, we use a model of a bipartite mutualistic network and show that a network's post‐transition state is indicated by the way in which a system recovers from minor disturbances. Similar results obtained with a unipartite model of facilitation suggest that our results are of relevance to a wide range of mutualistic systems.

Highlights

Empirical studies of lakes, arid ecosystems, coral reefs and tropical forests suggest that remarkably sudden transitions to alternative stable states may occur when changing environmental conditions pass a critical value (Scheffer et al 1993; Rietkerk & Van de Koppel 1997; Scheffer et al 2001; Hirota et al 2011)
To explore whether the direction of critical slowing down might be indicative of the future state of mutualistic communities, we use a model of a bipartite mutualistic network in which critical transitions are known to occur (Lever et al 2014; Dakos & Bascompte 2014; Jiang et al 2018)
Changing environmental conditions and the direction in which resilience is lost To test whether the direction of critical slowing down is indicative of a system’s future state, we study our ability to predict a system’s future state when changing conditions lead to substantial changes in the strength of positive feedbacks and the direction in which they have destabilising effects

Summary

Introduction

Arid ecosystems, coral reefs and tropical forests suggest that remarkably sudden transitions to alternative stable states may occur when changing environmental conditions pass a critical value (Scheffer et al 1993; Rietkerk & Van de Koppel 1997; Scheffer et al 2001; Hirota et al 2011). The species and interactions involved in the positive feedback leading to a critical transition, the direction in which this feedback amplifies change and the nature of a system’s future state are determined by the specific way in which interactions are altered.

Results

Conclusion