Distance sampling surveys reveal 17 million vertebrates directly killed by the 2020’s wildfres in the Pantanal, Brazil

Abstract

Anthropogenic factors have signifcantly infuenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfres is among the most visible consequences of human-induced climate change. Despite the fre role in determining biodiversity outcomes in diferent ecosystems, wildfres can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the frst-order impact of the 2020 wildfres on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers afected by fre. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fres in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fre recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fre over biodiversity and ecosystem services.