Intense human pressure is widespread across terrestrial vertebrate ranges

Abstract

The United Nation’s Strategic Plan for Biodiversity 2011-2020 calls for reducing species extinctions, as it is increasingly clear that human activities threaten to drive species to decline. Yet despite considerable scientific evidence pointing to the detrimental effects of interacting threats on biodiversity, many species lack information on their exposure to cumulative human pressures. Using the most comprehensive global dataset on cumulative human footprint, we assess the extent of intense human pressures across 20,529 terrestrial vertebrate species’ geographic ranges. We consider intense human pressure as areas where landscapes start to be significantly modified (a summed Human Footprint value at or above three on the index), which is where land uses such as pastureland appear. This threshold has been correlated with extinction risk for many species. We show that 85% (17,517) of the terrestrial vertebrate species assessed have >half of their range exposed to intense human pressure, with 16% (3328) of the species assessed being entirely exposed to this degree of pressure. Threatened terrestrial vertebrates and species with small ranges are disproportionately exposed to intense human pressure. Our analysis also suggests that there are at least 2478 species considered ‘least concern’ that have considerable portions of their range overlapping with these pressures, which may indicate their risk of decline. These results point to the utility of assessing cumulative human pressure data across species ranges, which may be a useful first step for measuring species vulnerability. Keywords: Human footprint, Extinction risk, Biodiversity conservation, Species threats, Overexploitation, Land use change, Urbanization, Land clearing