Paleoclimatic and vegetation reconstruction of the last 22,000 years of western Santa Catarina (Brazil) studied by pollen records

Abstract

This study reconstructs vegetation change in southern Brazil from a pollen record spanning the last 27,000 years. Five palynological phases were identified in a 154-cm core from the Floresta Nacional de Chapecó (Santa Catarina). Phase I (26,855–24,622 cal. BP) reflects colder-than-present conditions, with grasslands dominant and small patches of Araucaria Forest. Phase II (23,922–22,593 cal. BP) shows a further increase in grassland taxa, indicating a still-cold but more humid climate. Phase III (21,894–7,620 cal. BP) begins under cold conditions and then transitions to warmer conditions, particularly after 7,000 cal. BP. During Phase IV (6,595–2,355 cal BP), the Araucaria Forest expanded, followed by the spread of Seasonal Deciduous Forest; this interval corresponds to peak warmth and humidity in the sequence. Phase V (after 1500 BP) records forest retreat, especially toward the top of the core, likely associated with Euro-Brazilian colonization and the advance of the modern agricultural frontier.

Keywords: Palynology, Paleoenvironments, Quaternary, Brazil, South America.