Seastedt said his team will attempt to control Dalmation toadflax -- an ornamental plant introduced into North America from south-central Eurasia in the 1800s -- using several methods, including the use of insects as "biocontrols," he said. In the late 1990s Seastedt and his colleagues successfully controlled knapweed, a member of the daisy family that was taking over some Boulder County grasslands, by using a species of weevil to consume knapweed seeds and foliage, relegating it to a roadside weed.
A second invader targeted in the new study is cheatgrass, a winter annual that germinates in the fall and which is native to Eurasia. Seastedt said the researchers may use grazing animals and re-seeding with native grasses to combat cheatgrass parcels in the county during fall through late spring. This would allow native grasses to grow through late summer and early fall in an attempt to exclude resources like water and nitrogen from winter annuals like cheatgrass, he said.
The third invader targeted is Canada thistle, an exotic species introduced in North America from southeast Europe and Asia in the 1600s. "This species is of particular concern because it does not seem to have any major natural enemies," said Seastedt. "We need to find some competitive, desirable plants to reduce its abundance. But it will probably retain a presence in the county, specifically in parts of riparian habitats."
The middle school and high school students involved in the CU-Boulder project will be getting hands-on experience in working with different insect species that might be useful as control agents for invasive plant species, he said. "This effort will expose these students to real science, and hopefully kindle their interest in the many ecological changes occurring in the county, nation and world."
Seastedt said atmospheric pollution, climate change, exoti
|Contact: Timothy Seastedt|
University of Colorado at Boulder