Données palynologiques d'un milieu végétal dégradé dans la vallée moyenne du Rio Paraiba do Sul - Brésil Palynological data from a degraded landscape in the middle valley of the Paraiba do sul river in Brazil

摘要

Due to current and past environmental changes, i.e. the deforestation and coffee-implantation that occurred on an historical scale (the last 200 years) in the region of Vale do Rio Paraiba do Sul (Brazil), a colluvial layer of 20 to 50 cm thick, was formed. At Bananal (22°38'42"S ; 44°19'17"W, 650 m elev.) the sediments have been collected in four sections: Resgate, Sâo Joaquim, Bom Retiro and Bela Vista. This paper emphasizes the significance of the Palynology as a basis for environmental studies at Bananal. The high quantity of organic matter and the high level of preservation of the pollen content give, through pollen analysis, reliable evidence to clarify the possible changes that occurred during this time. The result shows a landscape and vegetation change such as the forest replaced by an open vegetation and coffee plantations.