An Announced Extinction: The Impacts of Mining on the Persistence of Arthrocereus glaziovii, a Microendemic Species of Campos Rupestres

The ironstone outcrops in the rupestrian grasslands, known as cangas, are rich in species of endemic plants. This high endemism and the constant threat because of the area loss and fragmentation make the conservation of the rupestrian grasslands necessary. The rupestrian grasslands that host one of Brazil's largest iron-ore mining areas are Iron Quadrangle. About 89 rare and endangered species of the Iron Quadrangle are exclusive to cangas, including a threatened species Arthrocereus glaziovii. According to the International Union Conservation of Nature (IUCN), this species is considered micro-endemic and endangered and a priority for recovering the Iron Quadrangle's ferruginous rupestrian fields. This work aims to evaluate the potential distribution of A. glaziovii based on abiotic variables and soil elements and characterize the distribution of mining titles that may restrict the areas of occurrence of this species. We used five types of ecological niche model (ENM) algorithms (Bioclim, Domain, MaxEnt, GLM and RandomForest) in two sets of environmental variables for the modeling: 20 climatic variables and 18 edaphic variables. Our results showed that the area of the potential occurrence of A. glaziovii is more extensive and covers areas outside the Iron Quadrangle. However, mining titles currently licensed and in exploration correspond the entire identified area, threatening the species' survival.