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 fe n, wooded moderate-rich fen, lacustrine sedge fen, and extreme-rich fe n) representing a bog to rich fen gradient in central Alberta was corr elated with water levels and several parameters of water chemistry mea sured during two growing seasons. Moss production generally showed gre ater variation between years than among sites, suggesting the influenc e of climatic factors such as temperature and precipitation. Moss grow th was greater in the year (1991) with higher mean water levels, surfa ce water NO3-, and air temperature. Vascular plant production showed g reater variation among sites than between years. Herb production corre lated with water level and pH-related parameters, while shrub producti on was negatively correlated with these parameters. Tree contribution to total production was minimal and seemed to be related to site dryne ss. Total aboveground production generally could not be correlated wit h any of the parameters that were measured, probably because individua l strata (e.g., herbs and shrubs) often correlated oppositely with env ironmental variables. Aboveground production tended to be greatest in sites with several well-developed vegetation strata (i.e., moderate-ri ch fen and poor fen).