 |
| Titel |
Trees are important conduits for emission of methane from temperate and tropical wetlands |
| VerfasserIn |
Vincent Gauci, Sunitha Pangala, David Gowing, Edward Hornibrook |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250084125
|
|
|
|
|
|
| Zusammenfassung |
| Methane produced in wetland soil generally is thought to be emitted to the atmosphere
primarily via diffusion through pore water, release of gas bubbles (i.e., ebullition), and gas
phase diffusion through the aerenchyma of herbaceous plants. The role of trees as a conduit
for methane export from soil to the atmosphere has received limited attention despite
evidence from mesocosm experiments showing that seedlings and saplings of wetland trees
have a significant capacity to transport soil-produced gases. Notably ~60% of global
wetlands are forested.
We present in situ measurements of methane flux from a temperate carr (swamp)
composed of alder (Alnus glutinosa) and birch (Betula pubescens) situated in the United
Kingdom and a tropical forested peat swamp located in Borneo. The in situ data are
complemented by a mesocosm experiment in which methane emissions were measured from
alder saplings subjected to two water-regime treatments. In both the in situ and mesocosm
studies, emissions from trees are compared to methane flux from the ground surface, the latter
occurring via pore water diffusion, ebullition or the aerenchyma of herbaceous plants. We
show that tree stem emissions are controlled by a number of factors including tree species,
soil pore-water concentration and stem lenticel density. Our results demonstrate that the
omission of tree-mediated methane fluxes from measurement campaigns conducted in
forested wetland can significantly underestimate total ecosystem flux of methane. |
|
|
|
|
|
|