@Article{RossettiBerZanCreHay:2012:ImOrSa,
author = "Rossetti, Dilce de F{\'a}tima and Bertani, T. C. and Zani, Hiran
and Cremon, {\'E}dipo Henrique and Hayakawa, E. H.",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Late Quaternary sedimentary dynamics in Western Amazonia:
implications for the origin of savanna/forest contrasts",
journal = "Geomorphology",
year = "2012",
volume = "177-17",
pages = "74--92",
month = "Dec.",
note = "{Setores de Atividade: Outras atividades de servi{\c{c}}os.}",
keywords = "• Amazonia, • Open vegetation–forest contrasts, •Paleomorphology,
Depositional system, Late Quaternarycontraste vegetacional,
savana, sedimentologia, Amaz{\^o}nia, sensoriamento remoto,
Quatern{\'a}rio.",
abstract = "This work investigated the evolution of sedimentary environments
during the latest Quaternary and their influence on the
paradoxical occurrence of open vegetation patches in sharp contact
with the Amazonian forest. The approach integrated pre-existing
geological and floristic data from lowlands in the Brazilian
Amazonia, with remote sensing imagery including multispectral
optical images (TM, ETM+, and ASTER), Phased Array L-band
Synthetic Aperture Radar (PALSAR), InSAR C-band SRTM-DEMs, and
high resolution images obtained from Google Earth. The detection
of an abundance of paleomorphologies provided evidence of a
scenario in which constant environmental shifts were linked to the
evolution of fluvial and megafan depositional systems. In all
studied areas, the open vegetation patches are not random, but
associated with sedimentary deposits representative of
environments either deactivated during the Holocene or presently
in the process of deactivation. Sedimentary evolution would have
determined the distribution of wetlands and terra firme in many
areas of the Amazonian lowlands, and would have a major impact on
the development of open vegetated patches within the modern
rainforest. Subsiding areas were filled up with megafan deposits,
and many fluvial tributaries were rearranged on the landscape. The
close relationship between vegetation and the physical environment
suggests that sedimentary history related to the evolution of
depositional settings during the latest Quaternary played a major
role in the distribution of flooded and non-flooded areas of the
Amazonian lowlands, with a direct impact on the distribution of
modern floristic patterns. As the depositional sites were
abandoned and their sedimentary deposits were exposed to the
surface, they became sites suitable for vegetation growth, first
of herbaceous species and then of forest. Although climate
fluctuations might have been involved, fault reactivation appears
to have been the main cause of changes in depositional dynamics
through time, a process that had an immediate effect on the
development of large open vegetation patches intermingled with the
Amazonian rainforest.",
doi = "10.1016/j.geomorph.2012.07.015",
url = "http://dx.doi.org/10.1016/j.geomorph.2012.07.015",
issn = "0169-555X",
label = "lattes: 0307721738107549 1 RossettiBerCreHay:2012:ImOrSa",
language = "en",
targetfile = "1-s2.0-S0169555X12003479-dilce.pdf",
urlaccessdate = "21 maio 2024"
}