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| Titel |
Pantropical Trends in Peatland Methane Fluxes |
| VerfasserIn |
Alison Hoyt, Laure Gandois, Alex Cobb, Sunitha Pangala, Vincent Gauci, Charles F. Harvey |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250147738
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| Publikation (Nr.) |
 EGU/EGU2017-11942.pdf |
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| Zusammenfassung |
| Wetlands are the largest source of methane (CH4) to the atmosphere and tropical peatlands in
particular offer ideal conditions for methanogenesis. However, prior work found
unexpectedly low CH4 emissions from tropical peat, based on measurements of surface
emissions using chambers (Jauhiainen et al., 2005). In contrast, our measurements
and modeling results show that CH4 production in these ecosystems may be an
order of magnitude higher than previously measured. We find that the relatively
rapid groundwater flow through tropical peatlands alters the relative importance of
transport pathways compared to northern peatlands. This is evident in CH4 and DIC
isotope and concentration data, which show strikingly similar trends across the
tropics, including in Panama and Brunei Darussalam (Holmes et al., 2015; Hoyt et al.,
2016).
This suggests strong pantropical trends in tropical peatland CH4 cycling. Here we
synthesize data on CH4 transport pathways in tropical peatlands. We find relatively little
ebullition and small surface fluxes relative to northern peatlands, which we can
replicate by modeling the high flow rates common in tropical peatlands. High rates
of oxidation also reduce surface fluxes. Tree transport plays an important role in
peatlands, but varies over orders of magnitude with tree species, leading to high
variability (Pangala et al., 2013; van Haren et al., 2016). We also assess the potential
for lateral subsurface transport of dissolved CH4, facilitated by high flow rates.
Finally, we address reasons methanogenesis may be inhibited in tropical peatlands. |
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