Ecological non-equilibrium and biological conservation

How to establish efficient conservation actions and policies for the long-term persistence of ecological systems remains a challenge. Conservation biology was born as a discipline of crisis, targeting the recovery of altered ecosystems under the paradigms of equilibrium and ecological stability. However, we argue that the concepts of ecological equilibrium and balance still hinder wildlife managers from optimizing proper decision-making and correctly prioritizing conservation actions. This is still the case, despite the prevailing paradigm has recently shifted to a more realistic view of non-equilibrium dynamics in ecosystems, even in the absence of anthropogenic impacts. The challenge for managers and policymakers is now even greater. First, because non-equilibrium is the basis for the Darwinian adaptive response of ecosystems, and hence maintaining variance, rather than decreasing it, should be the target of conservation. Secondly, ecosystems show non-linear responses (e.g. transients and critical transitions), which hamper diagnosis and prediction. Even though we are unable to suggest solutions to this conundrum, we warn here about potential biases when conserving non-equilibrium ecosystems. We suggest that insights from island ecology and medical science may be helpful when dealing with non-equilibrium in applied conservation. Incorporating the advances of the discipline of complex systems into the conceptual framework of management and policymaking may also contribute to improving the prioritization of actions, especially regarding some agents of global change. Finally, we advocate for the strengthening of the feedback between ecologists (both theoretical and empirical) and conservation practitioners to improve our knowledge on how ecosystems respond to perturbations.