Characterization of a glacial neotropical rainforest from pollen and spore assemblages (Colônia, São Paulo, Brazil)

Abstract

A total of 115 palynomorphs recovered from samples collected in the Colônia basin were described. The morphological descriptions were accompanied by illustrations and ecological information. The palynomorphs date back to the penultimate glacial with ages ranging from 135 to 180 ka. The palynomorphs were grouped according to their presence in three forest types represented in the Colônia basin, namely hillside forest, peat forest and swamp forest. The 115 identified taxa represent a total 58 families; one represents the algae, and 57 Embryophyta (ten pteridophytes, two gymnosperms and 45 angiosperms); 52% of the palynomorphs were observed in the three local forest types. 32.4% were observed in other types of vegetation distributed within a radius of 5 to 15 km from the basin. These palynomorphs represent mature forest, secondary forest, cloud forest, grassland, and disturbed environment whereas 15.6% of the palynomorphs were no longer observed in the region of Colônia. The species represented by these palynomorphs most likely disappeared from the region of Colônia during interglacial climate warming. In addition, our study provides reference material for future pollen studies in Colônia since some vulnerable species were identified.