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@Article{PangalaEBPBHGMCSBMGG:2017:LaEmFl,
               author = "Pangala, Sunitha R. and Enrich-Prast, Alex and Basso, Luana S. and 
                         Peixoto, Roberta Bittencourt and Bastviken, David and Hornibrook, 
                         Edward R. C. and {} and Gatti, Luciana Vanni and Marotta, Humberto 
                         and Calazans, Luana Silva Braucks and Sakuragui, Cassia 
                         M{\^o}nica and Bastos, Wanderley Rodrigues and Malm, Olaf and 
                         Gloor, Emanuel and Gauci, John Bharat Miller13 \& Vincent",
          affiliation = "{} and {} and {} and {} and {} and {} and {} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Large emissions from floodplain trees close the Amazon methane 
                         budget",
              journal = "Nature",
                 year = "2017",
               volume = "552",
                pages = "230--234",
                month = "Dec. 14",
             abstract = "Wetlands are the largest global source of atmospheric methane 
                         (CH4) 1 , a potent greenhouse gas. However, methane emission 
                         inventories from the Amazon floodplain2,3 , the largest natural 
                         geographic source of CH4 in the tropics, consistently 
                         underestimate the atmospheric burden of CH4 determined via remote 
                         sensing and inversion modelling4,5 , pointing to a major gap in 
                         our understanding of the contribution of these ecosystems to CH4 
                         emissions. Here we report CH4 fluxes from the stems of 2,357 
                         individual Amazonian floodplain trees from 13 locations across the 
                         central Amazon basin. We find that escape of soil gas through 
                         wetland trees is the dominant source of regional CH4 emissions. 
                         Methane fluxes from Amazon tree stems were up to 200 times larger 
                         than emissions reported for temperate wet forests6 and tropical 
                         peat swamp forests7 , representing the largest non-ebullitive 
                         wetland fluxes observed. Emissions from trees had an average 
                         stable carbon isotope value (\δ13C) of \−66.26.4 per 
                         mil, consistent with a soil biogenic origin. We estimate that 
                         floodplain trees emit 15.11.8 to 21.22.5 teragrams of CH4 a 
                         year, in addition to the 20.5  5.3 teragrams a year emitted 
                         regionally from other sources. Furthermore, we provide a topdown 
                         regional estimate of CH4 emissions of 42.75.6 teragrams of CH4 a 
                         year for the Amazon basin, based on regular vertical 
                         lowertroposphere CH4 profiles covering the period 20102013. We 
                         find close agreement between our top-down and combined bottom-up 
                         estimates, indicating that large CH4 emissions from trees adapted 
                         to permanent or seasonal inundation can account for the emission 
                         source that is required to close the Amazon CH4 budget. Our 
                         findings demonstrate the importance of tree stem surfaces in 
                         mediating approximately half of all wetland CH4 emissions in the 
                         Amazon floodplain, a region that represents up to one-third of the 
                         global wetland CH4 source when trees are combined with other 
                         emission sources.",
                  doi = "10.1038/nature24639",
                  url = "http://dx.doi.org/10.1038/nature24639",
                 issn = "0028-0836",
             language = "en",
           targetfile = "pangala_large.pdf",
        urlaccessdate = "04 dez. 2020"
}


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