The effect of peatland harvesting on snow accumulation, ablation and snow surface energy balance

Snow distribution, ablation and snowmelt energy balance components were characterized in a vacuum harvested and an adjacent undisturbed forested section of a peatland during the 2009 snowmelt period to determine snow distribution and melt dynamics on a previously harvested peatland, since abandoned and partly revegetated. The forested peatland had the deepest snowpack at 121cm, particularly along the edge of the forested section adjacent to the more windblown previously harvested peatland. The snowpack density was greatest in the harvested peatland, which was subject to greater wind compaction and mid-winter melt-refreeze episodes; however, snow water equivalence was higher in the forested peatland. Radiative fluxes dominated the snowmelt energy balance. Increased canopy cover within the forested peatland restricted incident radiation and delayed melt, whereas melt rates were rapid across the harvested peatland, driven by higher radiant and turbulent fluxes. Ablation calculated using a simple, one-dimensional model showed good temporal agreement with the observed ablation trends except when standing melt water pooled on the surface of the harvested section, causing more rapid modelled melt rates than observed. The shallower snowpack and more rapid melt across the harvested peatland limited the amount of melt water that was available for spring recharge.