Forested Wetland Mitigation: Developing Techniques to Restore Northern White-Cedar on Clay Settling Areas in Northern Michigan
Westley, S. R. 2022. Michigan Technological University
Abstract
When permitted activities degrade or destroy wetlands, mitigation is required by both
state and federal laws (Michigan Environment, Great Lakes & Energy (EGLE) and
Section 404 of the Clean Water Act). Forested wetlands are considered keystone
ecosystems, but restoration of these systems is often limited by the environmental
complexities and the slow growth of the long-lived tree species. Using a combination of
greenhouse and field experiments, my research goal was to develop techniques to create
northern white-cedar (Thuja occidentalis L.) forested wetlands in reclaimed/abandoned
mining quarries. There are numerous environmental stressors in the inorganic sediments
of reclaimed quarries including high moisture retention, low porosity, and lack of
nutrients. I tested using soil amendments in full factorial treatments using: fertilizer (F),
arbuscular mycorrhizae (AM), and organic matter. In addition to the soil amendment
experiments, I also tested how seedling survival was influenced by soil moisture. Our
results show that soil moisture had the greatest influence on survival in both the
greenhouse and field trials. The addition of organic matter and AM improved seedling
survival and growth while fertilizer decreased survival. My research indicates that the
addition of organic matter and planting at the right water table levels are the best
techniques to create forested wetlands in quarry sediments.
