Predicting variations in methane emissions from boreal peatlands through regression models

Frequently measured data from a boreal fen was used to test how regression models predict the spatial and temporal variations in methane emissions. In the spatial microscale, emissions were lowest from high hummocks with low water table and highest from the intermediately moist lawn with a high sedge cover. Seasonal variations were strong, but diurnal variations weak. The importance of episodic emissions increased from wet microsites to hummocks. The regression models explained the temporal pattern of methane emissions quite satisfactorily for flarks and low hummocks, but less satisfactorily for high hummocks. For independent data sets, the goodness of fit values were usually low. Episodic pulses and diurnal variations were not captured by the models and the models overestimated the spring emissions and underestimated midsummer high emissions.