Palynological differentiation of savanna types in Carajás, Brazil (southeastern Amazonia)

Abstract

Pollen rain studies in Amazonia are scarce but of utmost importance to support interpretations of pollen records. We have investigated modern surface pollen spectra and vegetation in an Amazon location, Carajás, Brazil, where open and woody types of vegetation, swamps and lakes develop under rock outcrops. Both plant inventories of different savanna types along with bryophytic surface samples were analysed with ecological ordination. The results point to taxa that can be used in the differentiation of dry and flooded systems within the savannas studied. Dry savannas, either open or wooded, are indicated by the herbs Cuphea, Asteraceae, Borreria, Caryophyllaceae and Polygonaceae, and by woody taxa such as Myrtaceae, Byrsonima, Sapotaceae, Neea and Rubiaceae. Flooded savannas (swamps) and lakes are indicated by herbs like Sagittaria, Montrichardia, Nymphaea, Cyperaceae and Mimosa and palms. Poaceae was found to have a bipolar signature, and using it as an indicator should be done with caution.