Areal differentiation of snow accumulation and melt between peatland types in the James Bay Lowland

Authors


Peter Whittington, Geography and Environmental Management, University of Waterloo, Waterloo, Canada.

E-mail: whittington.pete@gmail.com

Abstract

Snow accumulation and melt between various peatland types in the James Bay Lowlands is poorly understood despite being a significant source of fresh water to the saline James Bay. Many topographical factors that control snow accumulation and melt (e.g. slope, aspect) are not relevant in the James Bay Lowlands because of the extremely low relief. Thus, vegetation characteristics (e.g. winter leaf area index, tree density), which are strongly linked to peatland type, may dictate spatial patterns of snow accumulation and melt across the landscape. A 1.5-km long transect that bisected five peatland types representative of the local area was used to determine average snow depth, density and water equivalence for each of the landscape units. The peatland types were classified, in part, because of the density of treed vegetation and were named open bog, open shrub fen, low-density treed fen, medium density treed bog and high-density treed fen. Those with medium or high-density treed vegetation accumulated significantly more snow than those with low or open densities. Snow density, however, showed no correlation with landscape unit, and snowmelt proceeded at similar rates between all landscape units because of the relatively open canopy typical of this environment. A randomization test showed that the areally weighted basin average snow depth estimates varied by less than 10 cm as a result of the small but statistically significant differences in snow accumulation among landscape units. These differences are therefore relatively unimportant for accurately quantifying basin-wide snow depth in this landscape. Copyright © 2012 John Wiley & Sons, Ltd.

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