@Article{HilkerLTHMWBMS:2014:VeDyRa,
author = "Hilker, Thomas and Lyapustin, Alexei I. and Tucker, Compton J. and
Hall, Forrest G. and Myneni, Ranga B. and Wang, Yujie and Bi, Jian
and Moura, Yhasmin Mendes de and Sellers, Piers J.",
affiliation = "Oregon State Univ, Coll Forestry, Corvallis, OR 97331 USA. and
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. and NASA,
Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. and NASA,
Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.; Univ Maryland
Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228
USA. and Boston Univ, Dept Earth \& Environm, Boston, MA 02215
USA. and NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;
Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol,
Baltimore, MD 21228 USA. and Boston Univ, Dept Earth \& Environm,
Boston, MA 02215 USA. and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and NASA, Goddard Space Flight Ctr, Greenbelt,
MD 20771 USA.",
title = "Vegetation dynamics and rainfall sensitivity of the Amazon",
journal = "Proceedings of the National Academy of Sciences of the United
Sates of America",
year = "2014",
volume = "111",
number = "45",
pages = "16041--16046",
month = "Nov.",
keywords = "Amazon, climate change, precipitation, NDVI, MODIS, MAIAC.",
abstract = "We show that the vegetation canopy of the Amazon rainforest is
highly sensitive to changes in precipitation patterns and that
reduction in rainfall since 2000 has diminished vegetation
greenness across large parts of Amazonia. Large-scale directional
declines in vegetation greenness may indicate decreases in carbon
uptake and substantial changes in the energy balance of the
Amazon. We use improved estimates of surface reflectance from
satellite data to show a close link between reductions in annual
precipitation, El Nino southern oscillation events, and
photosynthetic activity across tropical and subtropical Amazonia.
We report that, since the year 2000, precipitation has declined
across 69\% of the tropical evergreen forest (5.4 million km(2))
and across 80\% of the subtropical grasslands (3.3 million
km(2)). These reductions, which coincided with a decline in
terrestrial water storage, account for about 55\% of a
satellite-observed widespread decline in the normalized difference
vegetation index (NDVI). During El Nino events, NDVI was reduced
about 16.6\% across an area of up to 1.6 million km(2) compared
with average conditions. Several global circulation models suggest
that a rise in equatorial sea surface temperature and related
displacement of the intertropical convergence zone could lead to
considerable drying of tropical forests in the 21st century. Our
results provide evidence that persistent drying could degrade
Amazonian forest canopies, which would have cascading effects on
global carbon and climate dynamics.",
doi = "10.1073/pnas.1404870111",
url = "http://dx.doi.org/10.1073/pnas.1404870111",
issn = "0027-8424",
label = "isi 2015-01 HilkerLTHMWBMS:2014:VeDyRa",
language = "en",
targetfile = "PNAS-2014-Hilker-16041-6hilker.pdf",
urlaccessdate = "11 maio 2024"
}