CORVALLIS - Although the last of western Oregon's native prairies are still threatened or being lost to housing, industry, agriculture and invading weeds, scientists at Oregon State University who are fighting to preserve these rich grasslands say there's now more cause for hope than in many years.
This ecosystem, which dates back to the last Ice Age and was nurtured by frequent fire set by Kalapuya Indians, has dwindled to less than 1 percent of its former range. There are now only 12 high-quality upland prairie sites left in the entire Willamette Valley.
Their continued existence is far more at risk than the region's old growth forests, researchers say.
But after years of study, recently increased funding and efforts to focus public attention on the demise of these ancient prairies, significant progress is being made.
"I'm actually pretty optimistic," said Mark Wilson, an associate professor of botany at OSU. "Our research programs are learning new things about how to promote native prairie plants. Volunteers are helping, educational programs are under way and we're really communicating to people the scope of the problem."
And a few, but very important, programs are now in place to fight back the invading weeds and non-native grasses, nurture the plants, insects and animals that historically belonged there, and bring badly-needed fire back to an ecosystem that evolved around it.
This summer and fall, for instance, OSU scientists will be collaborating with the Army Corps of Engineers, U.S. Fish and Wildlife Service, The Nature Conservancy and other groups on several important "controlled burns" of Willamette Valley grasslands.
And there are other signs of progress, Wilson said. High school students in Halsey are propagating native grasses for restoration efforts. Middle school students in Eugene are studying the preservation of native prairies as part of their science curriculum. OSU research has identified various regimes of burning, mowing, herbicide use or hand-removal that can help control invading plants.
"Consider Fender's blue butterfly, an insect which depends on a native plant called Kincaid's lupine for its survival," Wilson said. "It appears this butterfly may soon be listed as a threatened species. But partly through our recovery programs, in recent years its population at one site has doubled."
As much as anything, Wilson said, the mere fact that people are noticing, caring and taking action to preserve these historic grasslands is a sign of progress.
Prior to European settlement, both wetland prairie and native upland prairies dominated the Willamette Valley. Plants such as tufted hairgrass and Bradshaw's lomatium would flourish in the lower areas, while red fescue and wooly sunflower prospered elsewhere. Several plants grew here that were rare or nonexistent elsewhere in the world, and fires were frequently set by local Indians to improve wild game and plant habitat.
With settlement, the fires stopped, farms and cities grew and roads covered the land. Almost without notice until recent years, the ecology of native prairies was being destroyed. Bradshaw's lomatium is now officially an endangered plant, Nelson's checkermallow and peacock larkspur are threatened, and other plant and animal species may follow.
But in the 1990s the tide may have turned.
At the Baskett Slough National Wildlife Refuge near Salem, OSU scientists just in the past year have seen a dramatic resurgence of native fescue grasses after years of seemingly-ineffective efforts. They are learning how the Willamette daisy regenerates through studies on seed production, viability and germination. And studies at the Finley National Wildlife Refuge near Corvallis have used the volunteer work of high school and middle school teachers to learn much about the wetland prairie plant ecology.
Using controlled studies of fire ecology, research is determining how fire affects different plant species, what fire frequency and intensity works best, and places where it might actually be counterproductive. Using the new concepts of "adaptive management," scientists and public agencies are taking action to preserve and manage native prairies even as the science continues to evolve.
"There are a lot of plants that we still know so little about and are working to regenerate," said Deborah Clark, an OSU research associate. "They include slough grass, marsh speedwell, sedges and others. They're not easy to grow and it's a real challenge."
Various grants from The Nature Conservancy, Bureau of Land Management, and other federal agencies now give OSU scientists an annual budget of about $70,000 for basic ecological research and real-world application of the evolving knowledge.
"On one level, there's no doubt the problems are even worse in the past few years," Wilson said. "We've seen a housing subdivision and Christmas tree farm built on some of the last native prairie sites we had left. But the science is making progress, people are learning about the problem and they're listening. That's a big improvement."
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Mark Wilson, 541-737-5244