The Canadian Wetland Classification System

Abstract

Until the mid-1970s, efforts to classify and map Canadian wetlands were mostly uncoordinated with a diversity of approaches, goals, and priorities. In 1976, a Canadian Wetland Classification System (CWCS) was initiated which evolved into the Federal Policy on Wetland Conservation in 1991. The CWCS has developed in close association with wetland policy in Canada since then and is based on a three-level classification: five wetland classes (bog, fen, swamp, marsh, and shallow waters); wetland forms based on surface morphology, surface pattern, water type, and underlying soil morphology; and an open-ended number of wetland types based on physiognomic characteristics of vegetation communities. The “wetland type” level recognizes that field-level wetland classification and mapping requires practical local experience and input. The currently 49 wetland types used in the CWCS reflect vegetation communities, such as shrub, treed, graminoid, moss, lichen, and aquatics. This level allows regional approaches to site-level wetland classification to be part of the system.