Ecological Effects of Highway Construction Upon Michigan Woodlots and Wetlands: Soil Relationships

Ecological effects of recent highway construction on soils, hydrology, vegetation, and wildlife have been cooperatively evaluated for some common woodland and wetland types in central lower Michigan. A report on the soils portion of those Michigan Department of State Highways‐sponsored studies follows. Five woodland and five wetland areas representative of common situations encountered in highway location and planning studies were selected for analysis. A soil inventory was prepared for each area and the highway's impact on the soils was determined. The most significant effects of highway construction on the soil environment were the erosion of soil materials and the alteration of natural soil drainage conditions. Wetland areas are most sensitive to highway construction activities. Natural soil drainage conditions and circulation patterns are easily disrupted at these sites. Methods for predicting potential soil loss and potential changes in natural soil drainage conditions due to highway construction activities are suggested. The soil management group and unit designations used in Michigan are useful in making ecological impact predictions. A soil map of each proposed highway corridor or alternative right‐of‐way should be available early in planning of proposed highway construction. The soil map can be useful in predicting construction impact on the associated hydrology, plants, and animals in the area. These, in turn, are basic information in evaluating the economic and social impacts of the proposed route on the communities involved.