@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 = "23 abr. 2024"
}