Program turns invasive plants into energy
Plants might not be the most notorious invasive species in the Midwest. (Just try an internet search for “jumping Asian carp.”)
They are, however, invading regions and overtaking native species, entirely upsetting ecosystems. For these invasive plants, the common types of eradication aren’t necessarily the best solution—and the School of Environmental Sustainability (SES) is hoping to lead the change.
“Invasive plants are a huge and growing problem,” said Shane Lishawa, who leads Loyola’s on-the-ground efforts in the Great Lakes region. “There are new species constantly coming in.”
Getting those species under control is no easy task, especially in wetlands, where Lishawa works. Controlled burns are expensive and can only address small patches of land at a time. Herbicides can kill the non-native plants—right along with the native ones. And mowing them still leaves behind seeds and roots that resprout and material that decomposes to provide nutrients for a new generation.
So in 2010, Lishawa—along with Nancy Tuchman, PhD, the founding director of SES, and Dennis Albert, an assistant professor at Oregon State University—wrote a grant to try something different. They wanted to start harvesting the plants, removing them from the wetland, and using the “crop” to help the environment.
Today, that idea is still going strong. In 2015, SES's Invasives-to-Energy program marked its first year of large-scale harvesting. The program has spread to seven different wetlands around the Great Lakes, going as far as Ohio, and addresses three types of invasive plants.
The Invasives-to-Energy program aims to repurpose the harvested plants into different types of green energy. This is done either by grinding and compressing the material into biofuel pellets or by using anaerobic digestion to create bio-gas, which can then be used similarly to natural gas. The program’s efforts include small projects like a northern Michigan dairy farmer composting harvested invasive cattails (called Typha) and large ones like a partnership with the University of Wisconsin-Oshkosh to use those cattail plants to make bio-gas.
“The invasive cattail is this really big, productive plant that overwhelms the native plants in the wetlands, so the areas become these sort of biological deserts, with low diversity of plants and animals,” Lishawa said. “It’s so productive. It changes the soil—and that has implications for greenhouse gas emissions, nitrogen cycling, and all of these parts of the ecosystems.”
In another part of the program, Loyola is turning this cattail species and reed canary grass (Phalaris) into biofuel pellets—as part of a partnership with Oregon State University, DePaul University, Lake Superior State University, and the University of Michigan Biological Station. Those biofuel pellets can be used to heat a stove or boiler.
And the final plant being harvested is a common reed, native to Europe and the Middle East (Phragmites) for another bio-gas project.
“It’s been on the East Coast for a while, and then it moved across the country over the last 50 years with the recent low water levels in the Great Lakes,” Lishawa said. “It spread like crazy off the shoreline of Lake Huron, Green Bay, and Lake Michigan. It’s a relatively recent invasive plant to the Great Lakes and it’s huge. It can be 15 feet tall.”
Currently, the program is on its second three-year grant from the EPA’s Great Lakes Restoration Initiative, and Lishawa believes the collaboration will continue to have a long life going forward.
“We are at an inflection point,” Lishawa said. “We’ve made enough partners and we’ve done enough of this work that all of sudden a whole bunch of doors are opening. We have a lot of different organizations all over the region reaching out to us to try our technique on some of their property.”