SEASONAL-VARIATION IN WATER CHEMISTRY OVER A BOG-RICH FEN GRADIENT INCONTINENTAL WESTERN CANADA

Surface and subsurface (0.5, 1.0, and 1.5 m depths) water was sampled weekly in 1989 and biweekly in 1990 during the ice-free season along a bog-rich fen gradient in central Alberta. Acidity-alkalinity were mos t closely related to peatland type and were the most useful parameters for characterizing peatlands. Potassium, nitrogen, and phosphorus con centrations were more related to season, year, or peatland-year intera ctions and cannot be used to categorize the bog-fen gradient. Hydrogen ion, ammonium, alkalinity, and corrected conductivity were relatively constant throughout the ice-free season, while total metal ions (Al, Fe, Mn, and Zn), base cations (Ca2+ Mg2+, Na+, K+), nitrate, and compo nents of phosphorus fluctuated seasonally. Nitrate remained constant w ith depth in all peatland types, whereas ammonium increased with depth . Relationships of surface water chemistry to pH for all sites showed three patterns: a positive and highly significant correlation with lit tle seasonal variation within peatland types (base cations, alkalinity , and corrected conductivity); less significant correlation with stron g seasonal variation within peatland types (N and P); and a general ne gative and highly significant correlation with some seasonal variation in peatland types (metals and S). Water temperatures increased along the bog-rich fen gradient.