Mires boreal

Granberg et al. (2001) modeled CH4 emission from an oligotrophic lawn community in a boreal mire. Their representation of winter conditions (frost and snow) is the main difference between their model and that of Walter and Heimann (2000). The model was forced with daily mean air temperatures and daily accumulated precipitation. Methane was simulated with a model which separated CH4 emission by ebullition, diffusion, and plant transport. Oxidation was estimated by oxidation potential, which was centered at the water table. This model indicated that the mean level of the water table was the most important predictor of simulated CH4 emission, and that the presence of vascular plants is the most important factor in determining CH4 emission. These authors point out that their model contains tuning parameters that cannot be replaced by measurable parameters in the field. They called for focusing... 

Granberg G., Ottoson-Ldfvenius M., and Grip H. (2001) Effect of climatic variability from 1980 to 1997 on simulated methane emission from a boreal mixed mire in northern Sweden. Global Biogeochem. Cycles 15, 977-991. 

Granberg G., Sundh L, Svensson B. H., and Nilsson M. (2(X)1) Effects of temperature, and nitrogen and sulfur deposition, on methane emission from a boreal mire. Ecology 82, 1982-1998. 

Kettunen A., Kaitala V., Lehtinen A., Lohila A., Aim J., Silvola J., and Martikainen P. J. (1999) Methane production and oxidation potentials in relation to water table fluctuations in two boreal mires. Soil Biol. Biochem. 31, 1741-1749. 

Saarnio S., Saarinen T., Vasander H., and Silvola J. (2000) A moderate increase in the annual CH4 efflux by raised CO2 or NH4NO3 supply in a boreal oligotrophic mire. Global Change Biol. 6, 137-144. 

The major areas of peat formation today are raised mires, which are found in the tropics (e.g. Malaysia and Indonesia) and the temperate zone of the northern hemisphere. The boreal raised mires are dominated by moss (Sphagnum), whereas their tropical counterparts bear trees. As the raised mires develop, plant diversity decreases for example, the dipterocarp Shorea alhida is often the only tree on raised mires in north-west Borneo. 

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