@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 \−66.2±6.4 per
mil, consistent with a soil biogenic origin. We estimate that
floodplain trees emit 15.1±1.8 to 21.2±2.5 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 42.7±5.6 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 = "27 abr. 2024"
}