Forest type modulates mammalian responses to megafires.

Although considered an evolutionary force responsible for shaping ecosystems and biodiversity, fires' natural cycle is being altered by human activities, increasing the odds of destructive megafire events. Here, we show that forest type modulates the responses of terrestrial mammals, from species to assemblage level, to a catastrophic megafire in the Brazilian Pantanal. We unraveled that mammalian richness was higher 1 year after fire passage compared to a pre-fire condition, which can be attributed to habitat modification caused by wildfires, attracting herbivores and open-area tolerant species. We observed changes in assemblage composition between burned/unburned sites, but no difference in mammalian richness or relative abundance. However, by partitioning the effects of burned area proportion per forest type (monospecific vs. polyspecific), we detected differential responses of mammals at several levels of organization, with pronounced declines in species richness and relative abundance in monospecific forests. Eighty-six percent of the species presented moderate to strong negative effects on their relative abundance, with an overall strong negative effect for the entire assemblage. Wildfires are predicted to be more frequent with climate and land use change, and if events analogous to Pantanal-2020 become recurrent, they might trigger regional beta diversity change, benefitting open-area tolerant species.

Distance sampling surveys reveal 17 million vertebrates directly killed by the 2020's wildfires in the Pantanal, Brazil.

Anthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite the fire role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires 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 affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires 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 fire 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 fire over biodiversity and ecosystem services.

Historical survey of research related to fire management and fauna conservation in the world and in Brazil / Levantamento de artigos científicos relacionados à gestão do fogo e a conservação da fauna no mundo e no Brasil

Abstract: Fire is a key ecological factor affecting biodiversity structure and composition. Fires' effects on biodiversity can be beneficial or harmful depending on how, where, when, and why they occur. The impacts of fire on fauna vary according to species ecology and the fire regime. To understand the research effort relating fire, fauna, and mammals, we surveyed papers published in World and in Brazil. Only 5% of the publications between 1970 and 2019 with fire subject dealt with fauna and 0.5% with mammal. For Brazil, we obtained 7% of papers for fauna and 3% for mammal. The Brazilian Biome with more papers was Cerrado, followed by Atlantic Forest, Amazon, Pampas, Caatinga and Pantanal. The United States of America and Australia stand out as protagonists in their continents with the largest papers number. The volume of research is related to investment in Research and Development and to occurrence of fires. The slope of temporal trend shows the terms related to wildfire have more papers than prescribed burn and there is less interest in fauna and mammal research. It is necessary to form research groups with these themes as research lines and intensify research relating fire ecology and mammals. There is yet no unified understanding of how fire may influence animal diversity and how it influences the vegetative structure and subsequently the resources which wildlife rely on. We consider this information is essential to establish efficient conservation policies.

Resumo: O fogo é um fator ecológico que pode determinar os padrões de diversidade, estrutura e composição da biodiversidade. Assim, o fogo pode ser favorável ou prejudicial, dependendo de como, onde, quando e porquê ocorre. Os impactos do fogo na fauna variam de acordo com a ecologia das espécies e o regime de fogo. Levantamos a quantidade de artigos publicados no mundo e no Brasil para entender o esforço de pesquisa que relaciona fogo, fauna e mamíferos. Apenas 5% das publicações entre 1970 e 2019 com o assunto fogo tratam de fauna e 0,5% de mamíferos. Para o Brasil, obtivemos 7% dos artigos para fauna e 3% para mamíferos. O bioma brasileiro com mais artigos foi o Cerrado, seguido por Mata Atlântica, Amazônia, Pampa, Caatinga e Pantanal. Os países que se destacam como protagonistas em seus continentes, com maior número de publicações, são Estados Unidos da América e Austrália. O volume de pesquisas está relacionado aos investimentos em pesquisa e desenvolvimento e à ocorrência de incêndios florestais. A regressão linear demonstra que os termos relacionados a incêndios florestais têm mais publicações do que os relacionados a queimas prescritas e há menos interesse em pesquisas relacionadas a fauna e a mamíferos. Diante disso, acreditamos ser necessário formar grupos de pesquisa nesses temas e intensificar os estudos relacionando ecologia do fogo e mamíferos. Ainda não existe um entendimento único sobre a influência do fogo na diversidade de animais e na estrutura da vegetação e, subsequentemente, nos recursos dos quais a vida selvagem depende. Consideramos que essas informações são essenciais para estabelecer políticas públicas de conservação mais eficientes.