 |
| Titel |
Atmospheric exchange of carbon dioxide and methane of a small water body and a floating mat in the Luther Marsh peatland, Ontario, Canada |
| VerfasserIn |
Magdalena Burger, Sina Berger, Christian Blodau |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113796
|
| Publikation (Nr.) |
 EGU/EGU2015-14022.pdf |
|
|
|
|
|
| Zusammenfassung |
| Recent investigations have suggested that small water bodies cover larger areas in northern
peatlands than previously assumed. Their role in the carbon cycle and gas exchange rates are
poorly constrained so far. To address this issue we measured CO2 and CH4 fluxes on a small
water body (ca. 700 m2) and the surrounding floating mat in the Luther Marsh peatland in
Ontario, Canada from July to September 2014. To this end we used closed chambers
combined with a portable Los Gatos high-resolution trace gas analyzer at different water
depths and distances from the shore on the pond and with different dominating plant
types on the floating mat surrounding the pond. In addition, CO2 concentrations
were recorded in high temporal resolution using an infrared sensor system during
selected periods. Air and water temperature, humidity and temperature of the floating
mat, wind speed and direction, photosynthetically active radiation, air pressure
and relative humidity were also recorded as auxiliary data at the study site. The
results show that pond and floating mat were sources of methane throughout the
whole measuring period. Methane emissions via the ebullition pathway occurred
predominantly near the shore and on the floating mat. During the daytime measurements the
floating mat acted as a net sink and the pond as a net source of CO2. The dynamics
of CO2 exchange was also strongly time dependent, as CO2 emissions from the
pond strongly increased after mid-August. This suggests that photosynthesis was
more affected by seasonal decline than respiration process in the pond and that the
allochthonous component of the CO2 flux increased in relative importance towards fall. |
|
|
|
|
|
|