Phytoliths
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Paleoenvironmental Characterization of a High-Mountain Environment in the Atlantic Forest in Southeastern Brazil
ABSTRACT: Records of changes in the phytosociological structure of vegetation can be observed more clearly in soils that have more significant accumulation of organic matter, like those occurring in high-mountain environments. The aim of this study was to characterize soils formed in high-mountain environments in the Itatiaia National Park (INP), state of Ri
Rev. Bras. Ciênc. Solo. Publicado em: 14/11/2018
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2. Collection of reference of silicophytoliths the flora of the Southwest ParanÃ: subsidies for studies paleoenvironmental / ColeÃÃo de referÃncia de silicofitÃlitos da flora do Sudoeste do ParanÃ: subsÃdios para estudos paleoambientais
Phytoliths bodies are of amorphous silica (SiO2.nH20) produced during the vegetative cycle and plant death after the production can be incorporated into the soil/sediment, and may remain there for extended periods of time. For an analysis consistent fitolÃtica is necessary to compare the sets of phytoliths found in soil and the collections of references phy
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/03/2012
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3. Estabilidade da sílica biogênica extraída de capim Jaraguá (Hyparrhenia rufa) em solução de NaOH
Biogenic silica is used to describe compounds of hydrated silica (SiO2.nH2O), with specific shapes and sizes, deposited in plants. The chemical composition of biogenic silica and its stability in Jaraguá grass was studied in increasing concentration of NaOH. The analytical results demonstrated high concentration of Si, Al, Fe, Mg, P and low of Cu, Cd and Zn
Química Nova. Publicado em: 2010
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4. Ocorrência e significado paleoambiental do Horizonte A húmico em Latossolos / Occurrence and palaeenvironmental significance of humic horizon in Latosols (oxisols)
A ocorrência de solos com horizonte A húmico (Ah) hiperdesenvolvido ainda é pouco entendida. Nos Latossolos com esse horizonte (Lh) ele freqüentemente é muito espesso, com baixa saturação por bases e cor escura advinda do relativamente grande acúmulo de matéria orgânica até profundidades superiores a 100 cm. Exceto para a região Sul, tais atribut
Publicado em: 2009
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5. Termodecomposição, estudos de carbonização e silicificação da matéria orgânica e corpos silicosos em ecossistemas terrestres no Brasil e na Antártica / Thermodecomposition, organic matter carbonization silicification studies and silica bodies in terrestrial ecosystems in Brazil and Antarctica
Soil organic matter (SOM) is highly heterogeneous in composition, which consists of components as different from each other as labile carbohydrates and recalcitrant aliphatic compounds. Mean residence time (MRT) of the various compounds comprising soil organic matter may range from a few minutes to thousands of years. This wide range is partly due to the soi
Publicado em: 2007
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6. Opal phytoliths found on the teeth of the extinct ape Gigantopithecus blacki: implications for paleodietary studies.
Identification of opal phytoliths bonded to the enamel surface of the teeth of Gigantopithecus blacki indicates that this extinct ape had a varied diet of grasses and fruits. By using the scanning electron microscope at magnifications of 2000-6000x specific opal phytoliths were observed and photographed on the fossilized teeth of an extinct species. Since op
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7. Evidence for the control of phytolith formation in Cucurbita fruits by the hard rind (Hr) genetic locus: Archaeological and ecological implications
Many angiosperms, both monocotyledons and dicotyledons, heavily impregnate their vegetative and reproductive organs with solid particles of silicon dioxide (SiO2) known as opaline phytoliths. The underlying mechanisms accounting for the formation of phytoliths in plants are poorly understood, however. Using wild and domesticated species in the genus Cucurbit
National Academy of Sciences.
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8. Phytoliths in woody plants from the Miombo woodlands of Mozambique
Oxford University Press.
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9. The earliest archaeological maize (Zea mays L.) from highland Mexico: New accelerator mass spectrometry dates and their implications
Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from
The National Academy of Sciences.