The Cerrado and restinga pathways: two ancient biotic corridors in the Neotropics
Marie‐Pierre Ledru, Francisca Soares Araújo
Abstract
Previous scenarios of plant migration corridors between the two main rainforests of the Neotropics, the Amazon and Atlantic forests, are not satisfactory as they do not account for the modern distribution or the phylogeography of the taxa. Here, we enlarge the spatio-temporal scale of the different scenarios to better understand past connections between the Brazilian biomes. We used comprehensive published literature in phylogeography, ecology, paleoecology, paleoclimatology, paleoceanography, geomorphology in a multidisciplinary approach to reconstruct the migration of the plant taxa Podocarpus, Ilex, Hedyosmum, Myrsine. Two routes for cool taxa functioned during glacial periods, one ancient route that linked the Andes to the lowlands through the Cerrado and, another that used the coastal Restinga during the low sea level stands of the glacials. Marine pollen records provide evidence for the glacial expansion of a coastal vegetation, the Restinga, which included taxa of a cold type of grassland that today is sheltered at high elevations. The Cerrado is at the node of the migration of the taxa between the Amazon and Atlantic rainforests, from the Andes to the coast. The Brazilian mountain ranges are refugia of ancient taxa that colonized the continent up to the Andes and modified the floristic assemblages of the two rainforests during glacial periods. Today they need to be recognized and better protected.