Remnant wetlands under palm swamps in the Araripe Plateau, Brazilian semiarid

Palm swamps are typical of the plateaus in the Brazilian savanna, but they are present in remnant in the Brazilian semiarid region, exceptionally in selective concave sectors of the edge and steep slopes at the Araripe Plateau. This study aimed to investigate the genesis and evolution of remnant wet soils under buriti palms/palm swamps in the Brazilian semiarid. Three pedons were selected, described, and classified according to the World Reference Base for soil resources. Soil samples were collected from the surface down to the lithic contact at each pedon. Morphology, chemical, and physical attributes were analyzed. Optically stimulated luminescence (OSL) dating was applied to buried horizons at soil profile soil profile number 1. Our results show that remnant wetlands are associated with dynamics of the hydrogeological conditions and the regional relief, strongly influenced by the morphostructure and the current morphogenesis of the Araripe Plateau. In clear contrast with typical semiarid soils, the hydrolysis and ferrolysis have produced acid, hyperdystrophic, and C-rich horizons. Evidence of col-luvium and alluvium show that the soils are polycyclic. The ages between <200 to 850 yr reveal evidence of a parent material of colluvium/alluvial origin from a current sedimentation phase, attributed to erosion scarp, mass movements, and fluvial flow with low capacity.