Last glacial maximum (LGM) vegetation changes in the Atlantic Forest, southeastern Brazil

Abstract This study was carried out in a continental Atlantic Forest located in the southern region of Sao Paulo State, southeastern Brazil. The aim of the study was to evaluate the vegetation dynamics in ∼70 km forest ecosystem transect that occurred during the late Pleistocene and Holocene in this region, using the stable carbon isotopes (δ 13 C) analysis on soil organic matter (SOM) and the 14 C dating of buried charcoal fragments and the humin fraction of SOM. The isotope data (δ 13 C) of SOM in the deeper horizons, indicating the presence of more open vegetation than the present, with a probable mixture of C 3 and C 4 plants, suggesting the presence of a drier climate in the period of ∼20 ka to ∼16–14 ka BP. From ∼16 to 14 ka BP to the present, a significant predominance of C 3 plants was observed, indicating an expansion of the forest, probably associated with the presence of a more humid climate than the previous period. The results indicated the presence of open vegetation during the late glacial, probably associated with a drier period, also observed in other regions of Brazil. The Atlantic Forest ecosystem seems to have developed at least since the early Holocene in southeastern Brazil.