The Heart of the Matter

The Heart of the Matter

Environmental science students write plan to fight invasive species

From a distance, the yellow floating heart might seem like the perfect ornamental plant for your pond. But just below the water’s surface, the lily grows thick roots, develops mattes dense enough to stop a boat’s propeller, and outcompetes native plants.

The yellow floating heart plant originated in Eastern Asia and the Mediterranean, according to the U.S. Geological Survey. This lily is characterized by floating, heart-shaped leaves and bright yellow flowers.

Oklahoma State University became concerned with the yellow floating heart when it started growing in Lake Carl Blackwell, said Karen Hickman, OSU Environmental Science Program director.

“Lake Carl Blackwell is owned and managed by OSU,” Hickman said. “It provides the drinking water for the university campus and recreation, so it’s a vitally important body of water for OSU.”

OSU students in the environmental science graduate program were the first to conduct research on the plant.

“It was assessed about three to five years ago,” Hickman said. “They mapped the plant and found it was increasing at a rate close to two acres a year.”

The plant, which had covered up to 53 acres of the lake’s 3,350 acre surface area, was resistant to treatments of aquatic glyphosate, commonly known as aquatic Roundup, Hickman said.

“There were concerns about treating the aquatic plant with a chemical because it had the potential to contaminate a body of water that could be drinking water,” Hickman said. “When the glyphosate wasn’t very effective, OSU had to find something else.”

Hickman decided to make the yellow floating heart issue a project option in her environmental science capstone course. In the year-long course, studentsspend the fall semester researching their topics. During the spring semester, students develop potential plans of action.

Four students were assigned to the yellow floating heart project: Heath McDonald, Dallas Ladd, Shannon Wilson and Luis Martinez.

out to industry professionals and get their ideas of what they’d do in this situation,” McDonald said. “We did a lot of reading on the OSU library databases.”

“There’s not a lot of detailed information on how to control the yellow floating heart plants, so we had to reach

Lack of information was the team’s biggest challenge, McDonald said. They based their idea on research of similar lily species.

Collaboration with departments across campus, such as the environmental science graduate program, gave the student team the opportunity to improve their communications skills, Wilson said.

“We had to learn how to communicate with not only our peers, but also with professors and important people who had a lot of influence on the project,” Wilson said. “They were people who had a lot of knowledge about the yellow floating heart. So, learning how to communicate was a big thing.”

The undergraduate student team worked with the graduate students to gather data, Wilson said.

“They were the ones going out and collecting samples, taking pictures and gathering data,” Wilson said. “So, we had to communicate with them to get the research from them.”

The plant in Lake Carl Blackwell was tracked through satellite and drone images to determine surface area coverage, said Andrew Dzialowski, associate professor of integrated biology and an aquatic ecologist involved in the project.

The yellow floating heart plant is characterized by its yellow flower made of five petals and heart-shaped leaves.

Photo by Chelsea Dinterman.

Eventually, the students’ research led them to organizations in Wisconsin and Washington that had successfully dealt with the yellow floating heart plant, Hickman said.

“They were able to connect with a company that had a chemical approved for use — ProcellaCor,” Hickman said. ProcellaCor, a selective herbicide, “specifically targets a hormone mechanism that is unique to the plant,” which allows the user to kill nuisance plants while protecting wanted plants, according to SePro, producers of the chemical.

According to SePro, the product has less risk than other products and requires less product to control nuisance plants.

By the end of the capstone course, the students had written a comprehensive plan for dealing with the plant.

“The students identified the treatment,” Hickman said. “They came up with a proposal on how and when to treat it, how much it would cost and compared it to other treatment options. Then, OSU treated the yellow floating heart infestation this summer, incorporating some of the students’ recommendations.”

Before application of the herbicide, the university staff took precautions to ensure the safety of the water and natural ecosystems throughout Stillwater, Dzialowski said.

“The management at Lake Carl Blackwell worked with a certified applicator in the state,” Dzialowski said. “The planning brought in people of different expertise, including the Oklahoma Department of Environmental Quality and the Oklahoma Department of Wildlife Conservation.”

The yellow floating heart plant forms dense mattes that have hindered recreation at Lake Carl Blackwell. The plant roots in the soil and can spread in water up to 12 feet deep.

Photo by Harrison Hill.

The biggest precaution taken was temporarily changing the campus’ source of water while treatments were applied to Lake Carl Blackwell, Dzialowski said.

“That wasn’t required by law, but OSU thought it was appropriate,” Dzialowski said. “We did some water-quality testing. We collected samples at the water intake structure and point of entry for the water distribution system, and all samples were below detection limits for ProcellaCor in the water during treatment.”

After the ProcellaCor application, a significant reduction occurred in yellow floating heart coverage, Dzialowski said.

“The last time I checked, yellow floating heart covered between 2 and 3 acres of surface area,” Dzialowski said. “So, the treatment worked really well.”

Despite the treatment’s success, OSU will continue to monitor plant regrowth to determine next steps, Dzialowski said.

“The treatments were really successful, but it’s going to grow back in some places,” Dzialowski said. “There will probably be some need for additional applications, but I think we’re all really surprised at the success.”

By Chelsea Dinterman | Woodsboro, Maryland