Neotropical peatland methane emissions along a vegetation and biogeochemical gradient.
Abstract
Tropical wetlands are thought to be the most important source of interannual variability
in atmospheric methane (CH4) concentrations, yet sparse data prevents them from being
incorporated into Earth system models. This problem is particularly pronounced in
the neotropics where bottom-up models based on water table depth are incongruent with
top-down inversion models suggesting unaccounted sinks or sources of CH4. The newly
documented vast areas of peatlands in the Amazon basin may account for an important
unrecognized CH4 source, but the hydrologic and biogeochemical controls of CH4 dynamics
from these systems remain poorly understood. We studied three zones of a peatland
in Madre de Dios, Peru, to test whether CH4 emissions and pore water concentrations
varied with vegetation community, soil chemistry and proximity to groundwater sources.
We found that the open-canopy herbaceous zone emitted roughly one-third as much CH4
as the Mauritia flexuosa palm-dominated areas (4.7 ± 0.9 and 14.0 ± 2.4 mg CH4 m-2
h-1, respectively). Emissions decreased with distance from groundwater discharge across
the three sampling sites, and tracked changes in soil carbon chemistry, especially
increased soil phenolics. Based on all available data, we calculate that neotropical
peatlands contribute emissions of 43 ± 11.9 Tg CH4 y-1, however this estimate is subject
to geographic bias and will need revision once additional studies are published.
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https://hdl.handle.net/10161/15696Published Version (Please cite this version)
10.1371/journal.pone.0187019Publication Info
Winton, R Scott; Flanagan, Neal; & Richardson, Curtis J (2017). Neotropical peatland methane emissions along a vegetation and biogeochemical gradient.
PLoS One, 12(10). pp. e0187019. 10.1371/journal.pone.0187019. Retrieved from https://hdl.handle.net/10161/15696.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Neal Flanagan
Visiting Assistant Professor
Curtis J. Richardson
Research Professor of Resource Ecology in the Division of Environmental Science and
Policy
Curtis J. Richardson is Professor of Resource Ecology and founding Director of the
Duke University Wetland Center in the Nicholas School of the Environment. Dr. Richardson
earned his degrees from the State University of New York and the University of Tennessee.
His research interests in applied ecology focus on long-term ecosystem response to
large-scale perturbations such as climate change, toxic materials, trace metals, flooding,
or nutrient additions. He has specific interests in phosphor
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