Vegetation - habitat changes caused by damming a peatland drainageway in northern Ontario

Abstract

A striking example of road damming in wetlands is found 3 miles (5km) south of Kenogami, Ontario, where Highway 11 crosses a narrow, slowly drained, peatland valley. Below the road dam is forested peatland, with a central treed bog zone and swamps at the margins. Above the road dam is an open, floating-to-spongy, mostly Sphagnum-dominated mat which is bog in the poorest central areas and fen in the less poor marginal areas near small collecting pools and beaver channels. Measures of vegetation and habitat from quadrats along transects above and below the road dam suggest that there is continuous variation between fen and bog, and between swamp and treed bog. The open and treed bogs are interpreted as minertrophic transitional bogs. Implications of the changes caused by the road dam for other road-building and damming activities in northern Canada are discussed.