Roadless areas in Brazil: land cover, land use, and conservation status

Roadless areas (RLAs) are places with little to no influence of roads, usually sustaining well-preserved habitats, whereas road-effects zones (REZs) are areas affected by roads. Here, we map and characterize RLAs and REZs in Brazil, using national and international road network, land use and land cover, and protected areas databases. Following a global scale study, RLAs were defined as areas within ≥ 1 km from roads. Considering only paved roads, 8.2 M km2 (95%) of Brazil’s territory is RLAs, a figure that reduces to 6.8 M km2 (81%) when all built roads are included. In Brazil, the furthest location from roads is in the Amazon, 321 km away from the nearest road. Although RLAs differs among the Brazilian ecosystems, some common patterns emerge: (i) There is a lower percentage of natural vegetation cover on REZs than in RLAs, except for the Pampa; (ii) RLAs are mostly composed by natural vegetation, except in the Atlantic Forest, where farming lands dominate; (iii) protected RLAs are mostly covered by natural vegetation. Only 36.9% of Brazil’s RLAs are inside protected areas or indigenous lands. Even so, given the ongoing expansion of the road network and agriculture frontier in Brazil, it is unequivocal the role of those protected areas in stopping those drivers, making it paramount to explicitly include RLAs when planning new protected areas. Lastly, we found a positive relationship between a RLA patch size and its native vegetation cover as well as a positive relationship between the percentage of a protected area covered by RLA and its native vegetation cover.