Wilderness areas—nature with no or minimal human disturbance—are rapidly decreasing in global extent. How important this last stronghold of intact ecosystems is in mitigating the biodiversity crisis, however, is unknown.
Seeking to quantify the value of wilderness areas, this study applied models of compositional turnover—or β-diversity—based on more than 65 million GBIF-mediated occurrences of vascular plants and invertebrates to predict differences in composition between wilderness and non-wilderness.
By identifying the areas on every continent that make the highest relative contribution to persistence of biodiversity, the study finds that wilderness buffers extinction risks in all biogeographical realms. The effect is more pronounced, however, in areas with larger remaining extent of wilderness, such as the Palearctic.
Overall, the probability of species extinction in non-wilderness areas is more than twice as high as in wilderness areas, and for some communities the loss of a single square km grid cell of wilderness signifies a reduction in species persistence of up to 14 per cent.