Teachers tackle Scotch thistle invasion

Educators from across Oregon and Washington worked together this summer to learn about invasive species and their impact on ecosystems and local economies. Sisters locals Bess Ballantine and Colleen Fox of Wolftree, and Rima Givot of Sisters High School participated in the five-day workshop. They learned how, by collaborative efforts, weeds such as Scotch Thistle (Onopurdum acanthium) can be controlled.

A total of 10 teachers participated in the Plants on the Move workshop July 30-August 3 at the Malheur Field Station, southeast of Burns.

During the five-day conference the teachers experienced the process of conducting a service learning project, beginning with learning about invasive weeds. They identified many of the local native and invasive plants and examined management methods. They found that weeds tend to grow in disturbed areas, and left unattended will aggressively populate these places.

While learning about the area, they visited the historic Round Barn built by Pete French in the 1870s. The land around the structure was covered by many different weed types, such as Canada thistle (Cirsium arvense), perennial pepperweed (Lepidium latifolium), bull thistle (Cirsium vulgare), Russian thistle (Salsola tragus), and Scotch thistle (Onopurdum acanthium). All of these plants are invasive and compete with the local ecosystem.

The teachers learned that plants have different life cycles, which determine the appropriate control methods. Some plants can be effectively pulled, while others respond better to chemical treatment. Invasive species can also be managed by biological means, fire, or livestock grazing.

The group observed Scotch thistle overtaking a one-tenth acre along an earthen dam in an area that is flooded annually by Dry Lake. The thistle was in full bloom with flowers practically bursting to spread their seeds. Later on their tour, the teachers told the landowner about the weed infestation. The landowner replied: "Why didn't you just pull them when you were up there?"

The educators explored opportunities for student-level field investigations through service learning. They were presented with the challenge to develop and implement their own three-hour service learning project. They recognized the urgency to remove the Scotch thistle near Round Barn. If left to go to seed, those plants would not only expand their range in the local area (eventually reaching the historic Round Barn), but also send seeds down the floodplain that occurs from the Steens Mountain snowmelt.

The teachers collaborated in the planning and operation of the project, practicing what they hope to do with their students in the future. Then they greased their elbows and, with the help of many natural resource experts, spent three hours clipping the flower heads and cutting down the 6-foot-tall plants.

With an average plant holding 215 flowers, the teachers estimated they took out at least 7 million seeds from the plot.

"I was struck by how just 20 plants from the previous year could expand so quickly and potentially spread over such a wide area," said Wolftree educator Colleen Fox.

While managing invasive species can be daunting, the teachers experienced the satisfaction of working together and tackling a small area. With deliberate action, they found that an area can be restored to a more natural state, and with no action, devastating invasions can occur.

The teachers plan to translate these learning experiences into service learning projects for their students. The educators will also incorporate curriculum from Project Learning Tree (K-8) and "Invasives: Plants on the Move" (K-12). Both programs are aligned with state and national education standards. This curriculum taught in conjunction with service learning projects, promotes critical thinking and creative problem-solving, while simultaneously helping students feel connected to their community and environment.