Getting to the root of the matter
Floods and soil erosion, conditions that have been worsening in the Midwest over the last few years, can rob Iowa of its fertile soil. Although many solutions have been proposed, such as levees, terraces and wetlands, they are often short term. "To address the problem at its source, we have to look at the function of plants on the landscape," said Laura Jackson, University of Northern Iowa professor of biology.
Jackson and her students open a pot to reveal the roots and turface, which was used as a rooting medium.
Instead of looking at conventional solutions, Jackson is looking underground – at the roots of growing plants. Perennial prairie plants, with their massive root systems, help slow runoff, trap sediments and pollutants and rebuild the structure of damaged soil while storing atmospheric carbon, she explained. "Perhaps because these roots are invisible, many people lack a clear understanding of what native plants can do."
Following this logic, Jackson decided what was needed was to make the prairie roots visible. With funds she received from the Living Roadway Trust Funds (LRTF) in 2009, she began a project to do just that – to grow the plants in such a way as to reveal the intricate network of roots and then create a public display of the native prairie underground, with supporting interpretive materials for a wide audience.
Using and idea pioneered at the Land Institute in Kansas, Jackson and her students constructed a "big pots" facility at UNI in 2009-10. The 34 pots, made of PVC pipe 10 inches in diameter and 10 feet long, were "planted" vertically in a plot behind UNI's Biology Research Complex. Turface was used as a rooting medium for a variety of perennial species, and the plants were fed with an automated fertilizer-water system during the summer time.
The first growing season, in summer 2010, demonstrated that grasses were easier to establish than forbs, but there was also some winter kill. The first attempt at pulling pots and washing out roots was in fall 2010. Three pots were pulled out with a backhoe lift; roots were washed out and soaked in a glycerin solution for preservation. In one year, the roots had grown between three and four feet. When pots were pulled in 2011, the roots of the plants were six feet maximum in length, with a fuller, thicker root ball than in 2010.
With continued LRTF funding approved in July 2011, the project's goals through 2013 are focusing on developing and testing ways to transport, display and protect specimens; researching the interpretive material by collaborating with UNI faculty and end-users such as nature center directors and high school science teachers; and loaning out the 10 to 12 specimens as prototype exhibits.
This fall, Jackson and her students plan to to pull out and process one third of the 34 potted plants, while at the same time refine methods of preservation and storage. They also plan to begin developing the exhibit, first by assessing the needs of their intended audience, such as county nature centers and science classrooms. They will also consult with a variety of UNI faculty and staff with expertise in biology, chemistry, science education, communications and design arts. The group will investigate collaborations with various campus organizations to construct root exhibits.
"Our goal is to increase Iowa's resilience to heavy rainfall, soil erosion, water contamination and flooding," said Jackson. "Admittedly, this is a long-term and ambitious goal, but we hope that increased public understanding of how native perennial plants can contribute to a solution will be the first step to increasing the amount of perennial vegetation in the landscape."