Fræðaþing landbúnaðarins - 08.02.2008, Blaðsíða 543

VEGGSPJÖLD | 541
The results of this study indicate an increased emission with increased temperature
(18°C) for CO2 and CH4 (tables 2 and 3). The behaviour of the N20 emission does not
seem to be linear or exponential considering temperature. However, the emission effects
due to different land use managements are seen for all the three gases (see Figure 1, 2 and
3). The results indicate that, the land use management group seems to have a greater
impact on the overall average emission than temperature.
Many areas of the Icelandic peatlands have been drained. Some areas have been
converted to hay fields, others are used for grazing and some are abandoned. The results
in this study indicate that drained areas emit N20 in much greater quantities than the
originally undisturbed peatland. Wetlands are recognized as a source of CH4 production
in a natural state and draining reduces the CH4 emission. However, the effect of draining
as indicated in this study increase the N20 emission in addition to the increased C02
emission following the aerobic process of organic matter decay. Considering that N20 is
310 times as powerful greenhouse gas as C02, the final result of the draining can be an
increase of total GHG emission. A land use management plan must have a large scale
overview before changes are performed and all the participating GHG’s must be included
in the calculation to find the best solution to reduce the emission. Results from this study
indicate that anaerobic conditions decrease the N20 emission. By filling up ditches of
drained areas that are no longer in agricultural use we are able to decrease the emission of
C02 and N20 almost immediately due to anaerobic conditions.
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