Pollen record of a tropical peatland (Pau de fruta) from the serra do espinhaÇo meridional, diamantina, state of Minas Gerais – angiosperms eudicotyledons

This study presents the qualitative pollen analysis of a record of Pau de Fruta peatland, from the Serra do Espinhaço Meridional, Diamantina, State of Minas Gerais, Brazil, in order to investigate past changes in vegetation and climate as well as to provide reference material for the palaeoenvironmental reconstruction inserted in the Cerrado biome, currently found in the studied region. The analysis involved 21 stratigraphic levels from a core sample of 428 cm in lenght, corresponding to the last 10,596 ± 102 years cal BP. The chemical preparation consisted of application of HCl, HF, acetolysis, ultrasound, and mounting the slides in glycerin gelatin. The analyses were carried out under an optical microscope. A total of 128 pollen types, related to 57 families of eudicotyledonous angiosperms were identified and illustrated. These pollen types were related to forest phytophysionomies, represented by the semideciduous forest and mountain forest, and the Cerrado (broad sense) phytophysionomies, including savanna formations (“Cerrado Típico”, “Cerrado Ralo” and “Cerrado Rupestre”), forest areas (“Cerradão”) and grassland formations (“Campo Limpo Seco”, “Campo Limpo Úmido” and “Campo Rupestre”). Ecological information on organisms of origin, as selectivity to light and humidity, were described to provide inferences of environments of occurrence. Wet and cold conditions (~10,000–7360 cal BP), followed by wet and warm (~7360–4200 years cal BP), dry and warm (~4200–2200 years cal BP), dry and punctuated cooling (~2200–1160 cal BP) until current sub-humid climatic conditions (~1160–400 years cal BP and < ~400 years cal BP) are suggested by the succession of vegetation.