The wetlands of Elk Island National Park: Vegetation classification, water chemistry, and hydrotopographic relationships

Abstract

The wetlands of Elk Island National Park, located in central Alberta, are characterized by their vegetation and relationships between vegetation, surface water chemistry, and hydrotopographic parameters. Thirteen marsh, swamp, fen, and bog communities are described on the basis of TWINSPAN and the Canadian Wetland Classification System. Species distribution in Elk Island is related to surface water cation gradients of corrected conductivity, pH, calcium, magnesium, and sodium. Hydrotopographic features such as water level, hummock height, elevation of the site, and the number of inlet and outlet streams are of secondary importance. Nutrient levels (nitrogen and phosphorus) in surface waters are less significant. Significant correlations were not obtained between vegetation and surface water nitrate levels or peat depth. Marshes, swamps, and moderate-rich fens at Elk Island are circumneutral in pH and rich in calcium, magnesium, and sodium. Poor fens and bogs are acidic, with lower amounts of mineral cations. The ionic gradient at Elk Island is related to fluctuating water tables and water source (ombrogenous vs. minerogenous). Hydrotopography influences the water chemistry. At Elk Island, marshes and swamps are low elevational wetlands and have the highest number of inlet and outlet streams; fens are found at intermediate elevations with fewer inlet and outlet streams; and bogs are found at the highest elevations with the fewest number of inlet and outlet streams.