Net aboveground primary production along a peatland gradient in central Alberta in relation to environmental factors

The aboveground net primary production of five peatlands (bog, poor fen, wooded moderate-rich fen, lacustrine sedge fen, and extreme-rich fen) representing a bog to rich fen gradient in central Alberta was correlated with water levels and several parameters of water chemistry measured during two growing seasons. Moss production generally showed greater variation between years than among sites, suggesting the influence of climatic factors such as temperature and precipitation. Moss growth was greater in the year (1991) with higher mean water levels, surface water NO3-, and air temperature. Vascular plant production showed greater variation among sites than between years. Herb production correlated with water level and pH-related parameters, while shrub production was negatively correlated with these parameters. Tree contribution to total production was minimal and seemed to be related to site dryness. Total aboveground production generally could not be correlated with any of the parameters that were measured, probably because individual strata (e.g., herbs and shrubs) often correlated oppositely with environmental variables. Aboveground production tended to be greatest in sites with several well-developed vegetation strata (i.e., moderate-rich fen and poor fen).