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	Provedor de dados Anais da ABC (AABC) (3) Autor Toledo,Mauro B. de (3) Bush,Mark B. (2) Barros,Marcia A. (1) Barth,Ortrud M. (1) Silva,Cleverson G. (1) Palavra-chave Amazonia (2) Climate change (2) Pollen record (2) Hydrology change (1) Lagoa Salgada (1) Multivariate analysis (1) Palaeoecology (1) Palaeofires (1) Paleoenvironmental reconstruction (1) Quaternary palynology (1) Savannas (1) Vegetation change (1) Mais... Tipo do documento Info:eu-repo/semantics/article (3) Ano 2009 (1) 2008 (2) País Brazil (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última A Holocene pollen record of savanna establishment in coastal Amapá Anais da ABC (AABC) Toledo,Mauro B. de; Bush,Mark B.. The main goal of this study was to investigate how climate and human activities may have influenced ecotonal areas of disjoint savannas within Brazilian Amazonia. The fossil pollen and charcoal records of Lake Márcio (Amapá) were used to provide a Holocene palaeoecological history of this region. Detrended correspondence analysis (DCA) was used to enhance the patterns of sample distribution along the sediment core. A marked vegetation change from closed forests with swamp elements to open flooded savanna at c. 5000 yrs BP was evident from the pollen record. Charcoal analysis revealed a pattern of increased accumulation of particles coincident with the establishment of savannas, suggesting higher fire frequency and human impacts near the lake. A 550-year... Tipo: Info:eu-repo/semantics/article Palavras-chave: Pollen record; Palaeofires; Amazonia; Savannas; Climate change; Palaeoecology. Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000200013 Testing multivariate analysis in paleoenvironmental reconstructions using pollen records from Lagoa Salgada, NE Rio de Janeiro State, Brazil Anais da ABC (AABC) Toledo,Mauro B. de; Barth,Ortrud M.; Silva,Cleverson G.; Barros,Marcia A.. Despite the indisputable significance of identification of modern analogs for Paleoecology research, relatively few studies attempted to integrate modern and fossil samples on paleoenvironmental reconstructions. In Palynology, this general pattern is not different from other fields of Paleoecology. This study demonstrates the practical application of modern pollen deposition data on paleoenvironmental reconstructions based on fossil pollen by using multivariate analysis. The main goal of this study was to use Detrended Correspondence Analysis (DCA) to compare pollen samples from two sediment cores collected at Lagoa Salgada, a coastal lagoon located at northeastern Rio de Janeiro State. Furthermore, modern surface samples were also statistically compared... Tipo: Info:eu-repo/semantics/article Palavras-chave: Multivariate analysis; Paleoenvironmental reconstruction; Quaternary palynology; Lagoa Salgada. Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000400013 Vegetation and hydrology changes in Eastern Amazonia inferred from a pollen record Anais da ABC (AABC) Toledo,Mauro B. de; Bush,Mark B.. Pollen, charcoal, and C14 analyses were performed on a sediment core obtained from Lake Tapera (Amapá) to provide the palaeoenvironmental history of this part of Amazonia. A multivariate analysis technique, Detrended Correspondence Analysis, was applied to the pollen data to improve visualization of sample distribution and similarity. A sedimentary hiatus lasting 5,500 years was identified in the Lake Tapera. Because the timing of the hiatus overlapped with the highest Holocene sea-level, which would have increased the local water table preventing the lake from drying out, it is clear that sea-level was not important in maintaining the lake level. Lake Tapera probably depended on riverine flood waters, and the sedimentary gap was caused by reduced Amazon... Tipo: Info:eu-repo/semantics/article Palavras-chave: Vegetation change; Hydrology change; Amazonia; Pollen record; Climate change. Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000100014 Registros recuperados: 3 Primeira ... 1 ... Última

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