RESUMO
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.
RESUMO
Abstract: Information on distribution, number of populations, and biotic interactions are essential for assessing the threat status of species and to establish more effective conservation initiatives. Ecological niche modeling have been successfully applied to identify the potential distribution, even for rare species that have few recorded occurrence points. In this study, we evaluated the potential distribution and additionally generated the first data on the reproductive biology of Discocactus ferricola, due to its degree of threat and the absence of ecological data for that species. The potential distribution map highlighted areas with higher probability of occurrence of D. ferricola on the Residual Plateau of Maciço do Urucum located in Mato Grosso do Sul, Brazil. The occurrence of D. ferricola populations was limited to outcrops of flat ironstone (cangas) distributed in patches across the landscape, increasing the chances of serious threats, such as habitat loss due to mining and species extraction. We also found that D. ferricola is xenogamous. Therefore, in situ conservation actions must prioritize the maintenance of interactions with pollinators by preserving the flora and fauna of rocky outcrops and adjacent forests in areas of greater environmental suitability for D. ferricola. Our study highlights the use of ecological niche modeling and data on biotic interactions to evaluate species potential distribution, to guide new sampling efforts, and to assist conservation and management initiatives.
Resumo: Informações sobre distribuição, número de populações e interações bióticas são essenciais para avaliar o status de ameaça das espécies e estabelecer iniciativas de conservação mais eficazes. A modelagem de nicho ecológico tem sido aplicada com sucesso para identificar a distribuição potencial, mesmo para espécies raras que possuem poucos pontos de ocorrência registrados. Neste estudo, avaliamos a distribuição potencial e adicionalmente geramos os primeiros dados sobre a biologia reprodutiva de Discocactus ferricola, devido ao seu grau de ameaça e à ausência de dados ecológicos para essa espécie. O mapa de distribuição potencial destacou áreas com maior probabilidade de ocorrência de D. ferricola no Planalto Residual do Maciço do Urucum localizado em Mato Grosso do Sul, Brasil. A ocorrência de populações de D. ferricola foi limitada aos afloramentos ferruginosos planos (cangas) que são distribuídos em manchas pela paisagem, aumentando as chances de ameaças graves, como perda de habitat devido à mineração e extração da espécie. Também descobrimos que D. ferricola é xenogâmica. Portanto, ações de conservação in situ devem priorizar a manutenção das interações com os polinizadores através da preservação da flora e da fauna nos afloramentos rochosos e florestas adjacentes nas áreas de maior adequabilidade ambiental para D. ferricola. Nesse estudo, nós destacamos o uso da modelagem de nicho ecológico e de dados sobre interações bióticas para avaliar a distribuição potencial de espécies, orientar novos esforços de amostragem e auxiliar iniciativas de conservação e manejo.
