Roads and wetlands: the effect of Interstate 75 on a northern Michigan cedar swamp.

Abstract

A study of a northern Michigan cedar swamp that is bisected by Interstate 75. Vegetation transects reveal weedy species occupying the disturbed road edges and typical wetland vegetation in the swamp. Presence of invasive exotic plants is minimal. Water samples taken in the wetland and at the mouth of culverts by the highway reveal normal levels of ammonia and nitrate. Levels of chloride are high as a result of de-icing salts. This investigation showed that significant hydrological change is taking place, flooding a portion of the wetland, altering the composition of the plant community.