The role of a temperate constructed wetland in nutrient mitigation.

Abstract

This study assessed the effectiveness of a newly constructed 4.2 hectare wetland in Eastern Ontario as a sink for nutrients within an urban fringe watershed. During the initial two years after construction, the wetland was a sink for total phosphorus (TP) during the spring, summer and early fall. However, it was a large source of TP during late fall. During the spring, summer and early fall the wetland was a minor sink for total nitrogen (TN), but it was an effective mechanism for reduction of TN in late fall. An analysis of the nutrient retention capabilities of plant litter indicated that sediments of lower organic content may be more effective at P retention. The very different reactions of P and N to late fall anoxia in 1997 imply the need to focus design and management of constructed wetlands on the nutrient of major concern within the watershed. (Abstract shortened by UMI.)