On the Origin and Aftermath of Keystone Species

The term ‘keystone species’ plays a pivotal role in environmental policy by becoming a powerful agent to justify restoration and connect people with their surroundings. Yet, it became a popular buzzword used in international research up till numerous local level campaigns to foster stewardship and environmental awareness. It lacks a critical exploration of its (scientific) conceptual framing and ontological use, e.g., ecological keystone species versus cultural keystone species and biocultural keystone species. Through narrative synthesis of 2.746 studies, this scoping review examines the extent, range, and nature of keystone species research. By summarizing the findings from a body of knowledge that is heterogeneous in methods and discipline, we identify how the concept has proliferated into multiple fields of study and numerous inflections. From a critical point of view, we find that the keystone species theory opens a wide purview of the disequilibrium that has emerged from a paradigmatic distinction between ecosystem research and the social sciences. Moreover, we identify conflicting terminology on the basis of species entities, systems boundaries and scope of interaction. We argue that although the theory of keystone species has the potential to study human-wildlife coexistence in an era of mutualism, so far it largely manifests within, rather than across paradigms of scientific research. We conclude that a clear ontological frame of reference could be vital when applying the keystone species theory in research and praxis, as it has the potential to unravel the human dimensions of wildlife, within the dynamic balance of social-ecological systems.