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(Referência obtida automaticamente do SciELO, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Late Quaternary landscape evolution of northeastern Amazonia from pollen and diatom records

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Autor(es):
Castro, Darcilea F. [1] ; De Oliveira, Paulo E. [2] ; Rossetti, Dilce F. [3] ; Pessenda, Luiz C. R. [4]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Geociencias, Dept Geol Sedimentar & Ambiental, BR-05508080 Sao Paulo - Brazil
[3] INPE, BR-12245970 Sao Jose Dos Campos, SP - Brazil
[4] CENA, Lab 14C, BR-13400000 Piracicaba, SP - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Anais da Academia Brasileira de Ciências; v. 85, n. 1, p. 35-55, Mar. 2013.
Citações Web of Science: 5
Resumo

The main goal of this study was to reconstruct the Late Pleistocene-Holocene floristic composition in an area of the northern Brazilian Amazonia, comparing the results with other Amazonian localities in order to discuss the factors that have influenced phytophysiognomic changes over this time period. The work in eastern Marajó Island at the mouth of the Amazonas River was approached based on analysis of 98 pollen and diatom samples from core data distributed along a proximal to distal transect of a paleoestuarine system. The results indicated high concentration of Rhizophora, associated with arboreal pollen grains typical of the modern Amazonian rainforest during the last 40,000 cal yrs BP. Pollen composition also included wetland herbs. Diatoms were dominated by marine and fresh water taxa. Wetland forest, mangrove and, subordinately herbs remained constant during most of the latest Pleistocene-early/middle Holocene. At 5,000 cal yrs BP, there was a distinguished change from forest and mangrove to wet grassland savanna due to sea level fluctuation. As marine influence decreased, the estuary gave rise to fresh water lacustrine and swamp environments, with establishment of herbaceous campos. A main conclusion from this study is that solely the occurrence of herbaceous savanna can not be used as a definitive indicator of past dry climates in Amazonian areas. (AU)

Processo FAPESP: 04/15518-6 - Integração de dados biológicos e geológicos no Baixo Tocantins-Ilha do Marajó: chave na análise da biodiversidade
Beneficiário:Dilce de Fátima Rossetti
Linha de fomento: Auxílio à Pesquisa - Regular