The rupestrian marks identified over the Côa Valley are the evidence that the link between ungulates and Humans is a long tradition that dates back to the Palaeolithic period. By harnessing animal traction, humans have shaped Mediterranean landscapes for centuries, causing the degradation of ecosystem services and the extirpation of biodiversity, including wild ungulates. Today, the Côa Valley is characterized by an unparalleled level of land abandonment, which creates new opportunities for the comeback of wildlife through trophic rewilding, i.e. an environmental management option that can foster the restoration of biodiversity and ecosystem functioning by reintroducing medium and/or large ungulates in areas from where they were extirpated. As an emerging concept, trophic rewilding is controversial and there is no strong empirical knowledge to support its local implementation, social acceptance and ecological sustainability. The Côa Valley represents an outstanding outdoor laboratory to test and quantify the potential role of wild ungulates as ‘engineers’ of Mediterranean ecosystems. rWILD-COA will produce a wealth of knowledge to assist the implementation of self-sustainable ecosystems and to increase the predictability of rewilding outcomes. By integrating a variety of specialized teams and disciplines (e.g. ecology, microbiology, veterinary), rWILD-COA is aimed to i) predict how ungulates impact soil ecological processes and functioning (e.g. soil microbial activity, biogeochemical cycling) by grazing, grubbing, trampling and dunging, and study how these activities influence vegetation structure and invertebrate communities through soil nutrient mediation, ii) explore the direct and indirect pathways by which ungulates buffer or strengthen changes in species richness and diversity in the face of other environmental perturbations, such as climate warming, iii) evaluate the effects of extensive and intensive grazing and/or browsing on fire risk mitigation, and iv) analyse plant-soil feedback effects and the role of inter and intraspecific competition on foraging efficiency, diet quality and animal health of reintroduced individuals. rWILD-COA represents an approach of worldwide interest, where scientific evidences support the maintenance and/or restore of Mediterranean-type ecosystems.
