The unique and endangered Campo Rupestre vegetation and protected areas in the Iron Quadrangle, Minas Gerais, Brazil

Abstract

The Iron Quadrangle (IQ) in Brazil is one of the world's largest reserves of iron ore, and besides its economic importance, the region also plays a key role in nature conservation with the endemic Campo Rupestre vegetation. Despite a large number of protected areas (PAs) offering refuge for the remaining Campo Rupestre vegetation in the IQ, studies on the current situation of these natural remnants, and the real functionality of these PAs are scarce. This study aimed to map the remaining natural phytophysiognomies of the IQ, evaluating the proportion of Campo Rupestre on ferruginous and non-ferruginous substrates in PAs. We applied the object-oriented classification using Sentinel 2A and 2B satellite images, vegetation indexes, iron oxide index and terrain attributes, with field-collected validation points. We identified thirteen types of land use and cover, of which five represented natural phytophysiognomies. The most common phytophysiognomies in the IQ are Seasonal Forests and Cerrado (all types included), accounting for more than 60% of the total area. Campo Rupestre on ferruginous and non-ferruginous substrates accounts for 5.4% of the total mapped area only. On the other hand, about 42.5% of the Campo Rupestre (ferruginous or not) are protected and correspond to 17.7% of the PAs. We show that an appropriate mapping of the phytophysiognomies in the IQ region is key for improving landscape ecology knowledge and future conservation planning, especially of the endangered Campo Rupestre vegetation.