Fences and hydropower: Important but overlooked Human Footprint

Human activities have impacted 77% of the terrestrial ecosystems (excluding Antarctica), and the remaining areas are becoming increasingly endangered. Mapping spatiotemporal dynamics of Human Footprint has been used to evaluate the cumulative interference on terrestrial environments globally. However, fences and hydropower, two widespread and rapidly expanding infrastructures, have not been considered regarding Human Footprint, despite their complicated and extensive effects on ecosystem functioning and species survival. Previous work has proved that fences increase habitat fragmentation, disrupt migratory routes, inadvertently trap and kill wildlife, and hinder genetic exchange. Hydropower construction also caused habitat loss, fragmentation, and degradation. These impacts have received global concern, but fences around the world are difficult to be detected due to the limitations of current cartographic technologies. Furthermore, the effect of hydropower on the terrestrial environment has been underestimated, making the research on this topic at a global scale still in its infancy. Therefore, building an observation network of global fences and hydropower is a necessary step to move forward in the assessment of the impact of human activities on our planet, but also to better provide scientific support for policy-making regarding global biodiversity conservation, the identification of protected areas, and the prioritization of ecological restoration areas.