COLUMBIA — When a dozen or so MU researchers and students stepped onto a bare Hinkson Field on Thursday morning, their feet sank into the soft, rain-soaked ground as they planted 777 willow trees.
In the middle of the field, a murky pond was a remnant of the recent rain. One year from now, the trees they planted will be about 10 feet tall, and the researchers hope their thirsty roots will have absorbed any stagnant stormwater.
The field, near the intersection of Providence Road and Mick Deaver Memorial Drive and next to the Hinkson Creek, is being used as a part of a research project to study flood plain management and stormwater mitigation.
"It is an authentic flood plain experience," Kirsten Stephan, an urban forester at Lincoln University, said about the pond.
Stephan is collaborating on the study with two MU researchers. Jason Hubbart, an assistant professor of forest hydrology and water quality in the MU College of Agriculture, Food and Natural Resources, and Enos Inniss, an assistant professor of civil and environmental engineering in the College of Engineering, planted the trees as a part of a two-year study. They hope it will become a national model for areas that experience large amounts of stormwater runoff, which often carries pollutants into waterways.
Along with reducing the volume of stormwater retained in a flood plain, planting willow trees will create a potential cash crop for landowners that can be used for bioenergy, Hubbart said. Biofuels are derived from biological sources and provide renewable energy for heat, electricity and vehicle fuel.
"Given that the demand for biofuels is increasing, it makes willows an attractive cash crop because they are perennial trees," Stephan said.
Hubbart created a planting grid that divided the 108-by-60-meter field, owned by MU, into 3-by-3-meter squares.
Elliott Kellner, a graduate research assistant with Hubbart, was one of the people who helped plant the 5o eastern cottonwood willows, and the 727 black willows. He said there is a willow tree planted on each corner of every square.
Hubbart said he hopes that using this method of planting trees will not only mitigate the amount of stormwater, but also give landowners an incentive to grow forest trees in flood plain areas.
"The model creates an attractive payoff for doing something good," Hubbart said.
Flood plain soils such as the field along the Hinkson Creek get waterlogged easily, which makes them a risk for farmers. Even though the soil is fertile, the farmers can't predict when they will lose their crops due to flooding, Stephan said.
However, using species that are native to flood plain habitats and adapt easily to water logging could be a solution for restoring the plains to a more natural state, she said.
Hubbart and Inniss have partnered with the Campus Facilities Landscape Services for the project, which is being funded in part by the Environmental Protection Agency and MU Extension. Inniss has also been shortlisted for a grant from the Missouri Department of Natural Resources, which would provide $10,000 to purchase monitoring equipment. He expects to find out the status of the grant in early April.
Along with studying best managements practices of flood water and finding a long-term sustainable income base for landowners, the researches also hope to study how much carbon dioxide can be sequestered in the soil — although this component belongs to a larger project Hubbart is working on.
"Seventy percent of green house gas production happens in urban areas, so the greatest potential to mitigate climate change is also in urban areas," Stephan said.
Through urban flood plain forest restoration, carbon dioxide is being pulled out of the atmosphere through trees, she said.
"Urban trees may sequester greater quantities of carbon dioxide than their 'wildland' counterparts," Hubbart said. "The reduced flood volume is created by preferential flow paths for water created by tree roots, thus increasing infiltration rates and volumes."
At the same time, the tree roots increase the porosity of the soil, therefore increasing water holding capacity of the soil, he said.
Hinkson Creek has been designated an impaired water system by the state Department of Natural Resources since 1998. The Environmental Protection Agency identified numerous pollutants entering Hinkson Creek via stormwater runoff, according to a previous Missourian report.