Human land-use modifies the structure and composition of native ecosystems at varying scales and intensities, ranging from mild degradation (e.g., logged and secondary forests) to a virtual complete destruction (e.g., cattle pastures and tree plantations). Our understanding of the trade-off between hydroelectricity generation and biodiversity will be vital as many developing nations continue to expand hydropower infrastructure at the potential risk to natural capital. Despite known risks to freshwater biodiversity 5, dam construction is often assumed to not meaningfully affect terrestrial biota 6. Currently, 3700 hydroelectric dams (>1 MW of installed capacity) are under development 3, many in tropical developing countries which sustain high levels of biodiversity 4.
Hydropower development, aimed to accommodate rising global energy demands with minimal environmental costs, has become one of the major drivers of habitat loss, fragmentation, and degradation worldwide 1, 2. We recommend a more cautious pursuit of hydropower in topographically flat regions, to avoid extensive habitat flooding which has occurred in the Neotropics, and avoiding dam construction in priority conservation landscapes for tigers. Despite the relatively few dams (41) planned across the range of tigers, most will intersect priority conservation areas for this species. As hydropower infrastructure is projected to expand in the decades ahead, these values are expected to increase greatly, particularly within the distribution of jaguars where the number of dams will nearly quadruple (429 planned dams). For tigers, we identified 421 dams, amounting to 13,750 km 2. We found 164 dams intersecting the jaguar range, in total flooding 25,397 km 2.
To do so, we compiled existing and planned dams intersecting the distribution of these apex predators. To help fill this knowledge gap, we quantified the habitat loss following inundation of hydropower reservoirs across the range of two iconic species, jaguars and tigers. Despite known risks to freshwater biodiversity, the flooding of terrestrial habitats caused by dam construction, and associated impacts on terrestrial biota, have been rarely considered. The rapid expansion of hydropower across tropical landscapes has caused extensive habitat loss and degradation, triggering biodiversity loss.