Evaporation from a sphagnum moss surface

Abstract

Peat cores, 45 cm in diameter, were collected from a sphagnum bog in northern Minnesota, and used to measure the effects of different temperatures and water levels on evaporation from a sphagnum moss surface in a growth chamber. Under all conditions, evaporation from the moss surface was greater than that from a free-water surface. Evaporation from the moss increased 92% as the temperature was raised from 9° to 25°C. The energy used in evaporation from the moss exceeded net radiation except at 9°C. Evaporation from the moss was less when the water level was at the surface of the peat than when it was lowered to 5, 10, or 15 cm below the surface. The presence of an overstory of grasses and sedges protected the moss from desiccation when the water level was 15 cm below the surface, but had no effect on total water vaporization at any water level. When the peat cores were maintained in the greenhouse for a year, changes in either the peat, the moss, or both occurred which resulted in significantly lower evaporation when measured in the growth chamber.

Citation

Nichols, D.S.; Brown, J.M. 1980. Evaporation from a sphagnum moss surface. Journal of Hydrology. 48: 289-302.