Climatic linkage between eastern Brazilian biomes and the Pantanal wetland during the Late Pleistocene.
De Oliveira, Paulo1, Assine, Mário Luis 2, Pessenda, Luiz Carlos Ruiz*,3, Bezerra, Maria Angélica de Oliveira4, Mofatto, Milene3, 1 University of Guarulhos, Gurulhos, Sao Paulo, Brazil2 Department of Geology, Rio Claro, Sao Paulo, Brazil3 C-14 Laboratory, Piracicaba, Sao Paulo, Brazil4 University of Mato Grosso do Sul, Campo Grande, Sao Paulo, Brazil
ABSTRACT- Recent geochemical studies conducted in the present-day caatinga region of northeastern Brazil suggest very humid conditions during the Last Glacial Maximum.A Podocarpus forest covered the Central Brazilian Plateau from 24,000 to 13,000 yrs BP extending into the early Holocene suggests a synchronous humid and cool climates existed in the cerrado region. Pollen histories from the Atlantic Rainforest in the Curucutu Reserve in São Paulo, southeastern Brazil, indicate similar climatic signals during the Late Pleistocene, especially during the time of the Last Glacial Maximum at ca. 18,000 years BP. Therefore, it is possible that a north-south humid and cold climate belt that extended from northeastern Brazil (7°S), extending accross the Central Brazilian Plateau and reaching the Atlantic Rainforest belt in the State of São Paulo (23 ° S). The westward extension of this climatic belt to the Pantanal wetland (17-20 ° S) is still to be determined. The Nhecolandia landscape (Taquari megafan) has been interpreted as relict of eolian activity (salt pans) suggesting cold but drier conditions prevailing during the Pleistocene. Otherwise, pollen recovered from sediments of lakes associated with the Paraguay River system is suggesting a more complex paleogeographic scenario, with possible local variations of humidity and vegetation on the Pantanal wetland. The research is in progress. It will provide new insights into data to establish the precise initiation of the modern Pantanal wetland ecosystem.
Key words: Pantanal wetlands, climate linkage, eastern Brazil, Late Pleistocene
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