The response of vegetation to chemical and hydrological gradients at a patterned rich fen in northern Alberta, Canada

Study region: Across northern Alberta Canada, patterned rich fens, with high concentrations of base cations, high pH, and high species richness, are important landscape features. McClelland Wetland is one of the largest representatives of this peatland type. Study focus: We explored the surficial water chemistry and plant community patterns through a grid of 64 plots placed within a patterned rich fen of 420 ha. New hydrological insights for the region: Plant communities and individual species abundances are tightly associated with surface water chemistry and water levels influenced by inflowing waters from surrounding mineral soils. Based on location and string/flark size and orientation, five spatial areas are recognized to occur in the fen. Spatial Areas located in the northern portion of the fen have different water chemistry and plant communities than Spatial Areas of the center and southern portions of the fen. The water chemistry of the northern spatial areas contains about one-half of the cation concentrations than those from the southern spatial areas and the stoichiometry of the water is different between these regions of the fen. Distributions of dominant plant species are associated with differing water chemistries, and separated by a narrow transition zone. Water sourced from different areas of the surrounding watershed largely control the water chemistry and plant distributions within the patterned area.