Rewilding: A Call for Boosting Ecological Complexity in Conservation

Rewilding has emerged as an audacious conservation approach aiming at restoring wild species interactions and their regulation of ecosystem processes by focusing on the key role of species that have been extensively extirpated by humans. Rewilding has gained increasing attention from scientists, conservationists and the mass-media. Yet, it has raised highly divergent perspectives as to which ecological processes and species assemblages should be restored. Here we argue that a pragmatic and immediate approach to rewilding unequivocally focused on preserving and restoring the structural and functional complexity of ecosystems must become a primary component of biodiversity conservation. We propose a process-oriented formulation of the rewilding hypothesis as a general guide to assess the conservation benefits of reverting defaunation. Finally, we identify the need for a framework where the benefits, risks, and costs of rewilding can be evaluated in relation to restoration baselines and the intensity of interventions required to achieve conservation goals.