Palynological analysis of a core from the Atlantic rain forest region in Brazil provides unprecedented insight into late Quaternary vegetational and climate dynamics within this southern tropical lowland. The 576-cm-long sediment core is from a former beach-ridge “valley,” located 3 km inland from the Atlantic Ocean. Radio-carbon dates suggest that sediment deposition began prior to 35,000 14C yr B.P. Between ca. 37,500 and ca. 27,500 14C yr B.P. and during the last glacial maximum (LGM; ca. 27,500 to ca. 14,500 14C yr B.P.), the coastal rain forest was replaced by grassland and patches of cold-adapted forest. Tropical trees, such as Alchornea, Moraceae/Urticaceae, and Arecaceae, were almost completely absent during the LGM. Furthermore, their distributions were shifted at least 750 km further north, suggesting a cooling between 3°C and 7°C and a strengthening of Antarctic cold fronts during full-glacial times. A depauperate tropical rain forest developed as part of a successional sequence after ca. 12,300 14C yr B.P. There is no evidence that Araucaria trees occurred in the Atlantic lowland during glacial times. The rain forest was disturbed by marine incursions during the early Holocene period until ca. 6100 14C yr B.P., as indicated by the presence of microforaminifera. A closed Atlantic rain forest then developed at the study site.

Ecological restoration of trees is often constrained by limited knowledge of the biology, propagation and management requirements of individual species. Consequently, restoration initiatives rarely incorporate less well-known species or those that are difficult to source and grow. We describe challenges associated with the restoration of threatened trees in the Araucaria Forest of southern Brazil, and analyse the effectiveness of methods used to define target species, identify seed sources and generate information on the phenology of rare or threatened tree species. A review of secondary data identified 71 rare or threatened taxa as targets for seed collection. We then surveyed 68.7 km of trails in 26 forest remnants, identifying and mapping 1,027 seed-producing trees of 38 species. Surveys confirmed the scarcity of several tree species (including seven species with an abundance of <0.04 individuals per km), and nine species showed no signs of fruiting during 3 years of phenological monitoring. These findings, together with limited knowledge and application of optimal seed collection methods, are significant factors impeding the recovery of these species within their natural habitat. Wider application of the results of this case study could support restoration of the Araucaria Forest with seedlings from a wider diversity of species.