Restoring Great Lakes Wetlands
The University of Chicago’s School of Environmental Sustainability is working on a project to restore biological diverse wetlands at the Northern tip of Michigan’s lower peninsula. The research group is focused on combatting invasive plants that disrupt wetland ecosystems and crowd out native species. The project goal is to develop scalable management strategy for restoring high-quality habitats for birds, fish, and other wildlife.
The group recently secured a $1.1 million federal grant for a large-scale project that could effect wetland management throughout the Great Lakes region. The project is funded through the Great Lakes Restoration Initiative (GLRI).
Typha x glauca (Typha) is a cross between a non-native cattail and a native species. The hybrid tolerates a wide range of conditions and can spread quickly. Large cattails, reaching more than 10 feet tall, can quickly take over a marsh ecosystem. The cattails also leave a large amount of leaf litter. The accumulating biomass changes the structure of the wetlands making it more difficult for native species to grow.
Over the years, the team discovered the removing the cattails produced dramatic results. The native species came back and thrived. They tried using a mechanical harvester to remove the cattails above the water, but this method was less effective than removing the entire cattail. But digging up the whole cattail, along with the rhizome is labor intensive. So eventually, they discovered that using a machine to cut the cattails below the surface was more effective in restoring plant diversity. Since this was a mechanical tool it could also be scaled for larger applications.
The team went on to research how to best use the enormous amounts of biomass they were collecting. They found they could create biochar from the biomass. Biochar is a charcoal-like substance produced from heating organic materials in an oxygen-free environment. Without oxygen, the material burns cleanly and forms a carbon-rich product. Using this process no carbon is released into the air. Biochar is known to chemically bind vital plant nutrients such as nitrates and phosphates.
Runoff from farm fields creates nutrients that feed the rapid growth of cattails. The group is exploring ways to apply biochar to wetlands that may reduce the nutrient-rich conditions upon which the cattails thrive.
The group is now proposing a large scale experiment at the Shiawassee National Wildlife Refuge that would harvest the cattails in large sections and convert them into biochar on-site. The biochar would then be applied to the wetlands.
Student working with team Typha are developing valuable research skills and gaining direct, hands-on experience working to restore the wetlands. The work may help prepare them to be independent researchers in the future.