CGRG Bibliography of Canadian Geomorphology
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Author : Halsey, L.; and Devito, K.
Date : 2003.
Title : Patterned fens of the western Boreal Plain: the role of landscape and geology.
Publication : Canadian Geophysical Union. Annual Meeting, May 10 -14, 2003. Banff Centre, Banff, Alberta.
Issue :
Page(s) :
Abstract
Patterned fens on the western Boreal Plain consistently exhibit groundwater discharge to the surface. Sites located at the base of regional uplands experience discharge from either deep in the peat column or from the underlying mineral substrate, while patterned fens located near the summit of regional uplands experience discharge only from within the upper part of the peat column. The stratigraphic location that discharge occurs from is dependent on hydraulic conductivity as well as elevational differences in the surface watershed. Surface well water chemistries reflect their water sources with patterned fens located near the summit of regional uplands having low pH, alkalinity, and associated cations and anions, while patterned fens located at the base of regional uplands have higher concentrations. Nutrient concentrations (TDN, SRP, and TDP) are generally lower in patterned fens than their nonpatterned counterparts reflecting the flushing/dilution of decomposition products by nutrient depleted groundwaters. Pore water chemistries mimic those of surface well waters for points of discharge and diverge for points of recharge. Geology and landscape position of the western Boreal Plain determines the location and type of patterned fens. Groundwater discharge is required to maintain high watertables in the fall and subsequently allows for the development of a frozen layer at or above the fen surface on which sheet flow can occur in the spring. Acidic, poor fens are generally found near the summit of regional uplands while basic, rich fens are located at the base of regional uplands. Lower nutrient concentrations are a manifestation of groundwater discharge and may result in overall lower production in patterned fens relative to their nonpatterned counterparts, although this hypothesis remains to be tested.
Bibliography of Canadian Geomorphology