@Article{NepstadLSTSSRB:2004:BaAn,
               author = "Nepstad, Daniel and Lefebvre, Paul and Silva, Urbano Lopes da and 
                         Tomasella, Javier and Schlesinger, Peter and Solorzano, Luiz and 
                         Ray, Paulo Moutinho David and Benito, Jos{\'e} Guerreira",
          affiliation = "{CPTEC-INPE-Cachoeira Paulista-12630-000-SP-Brasil}",
                title = "Amazon drought and its implications for forest flammability and 
                         tree growth: a basin-wide analysis",
              journal = "Global Change Biology",
                 year = "2004",
               volume = "10",
               number = "5",
                pages = "704--717",
                month = "may.",
             keywords = "evapotranspiration, fire, hydrology, NPP, rainforest, soil 
                         moisture, tropical, water balance.",
             abstract = "Severe drought in moist tropical forests provokes large carbon 
                         emissions by increasing forest flammability and tree mortality, 
                         and by suppressing tree growth. The frequency and severity of 
                         drought in the tropics may increase through stronger El Nino 
                         Southern Oscillation (ENSO) episodes, global warming, and rainfall 
                         inhibition by land use change. However, little is known about the 
                         spatial and temporal patterns of drought in moist tropical 
                         forests, and the complex relationships between patterns of drought 
                         and forest fire regimes, tree mortality, and productivity. We 
                         present a simple geographic information system soil water balance 
                         model, called RisQue (Risco de Queimada - Fire Risk) for the 
                         Amazon basin that we use to conduct an analysis of these patterns 
                         for 1996-2001. RisQue features a map of maximum plant-available 
                         soil water (PAW(max)) developed using 1565 soil texture profiles 
                         and empirical relationships between soil texture and critical soil 
                         water parameters. PAW is depleted by monthly evapotranspiration 
                         (ET) fields estimated using the Penman-Monteith equation and 
                         satellite-derived radiation inputs and recharged by monthly rain 
                         fields estimated from 266 meteorological stations. Modeled PAW to 
                         10 m depth (PAW(10 m)) was similar to field measurements made in 
                         two Amazon forests. During the severe drought of 2001, PAW(10 m) 
                         fell to below 25% of PAW(max) in 31% of the region's forests and 
                         fell below 50% PAW(max) in half of the forests. Field measurements 
                         and experimental forest fires indicate that soil moisture 
                         depletion below 25% PAW(max) corresponds to a reduction in leaf 
                         area index of approximately 25%, increasing forest flammability. 
                         Hence, approximately one-third of Amazon forests became 
                         susceptible to fire during the 2001 ENSO period. Field 
                         measurements also suggest that the ENSO drought of 2001 reduced 
                         carbon storage by approximately 0.2 Pg relative to years without 
                         severe soil moisture deficits. RisQue is sensitive to spin-up 
                         time, rooting depth, and errors in ET estimates. Improvements in 
                         our ability to accurately model soil moisture content of Amazon 
                         forests will depend upon better understanding of forest rooting 
                         depths, which can extend to beyond 15 m. RisQue provides a tool 
                         for early detection of forest fire risk.",
           copyholder = "SID/SCD",
                  doi = "10.1111/j.1529-8817.2003.00772.x",
                  url = "http://dx.doi.org/10.1111/j.1529-8817.2003.00772.x",
            isbn/issn = "1354-1013",
                 issn = "1354-1013",
             language = "en",
           targetfile = "Nepstad_Amazon drought and its implications.pdf",
        urlaccessdate = "27 abr. 2024"
}