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Noxious weeds a problem in all regions of the state
5/15/2013
Several invasive weeds are being highlighted during Invasive Weed Awareness Week

They are often called a biological wildfire. Invasive noxious weeds are plants that have been introduced into an environment outside their native range. In this case, they have come to Oregon, causing environmental and economic harm to some degree in all regions of the state. Governor Kitzhaber has declared May 19-25 as Oregon Invasive Weed Awareness Week with hopes that the public can help fight the battle against these unwanted invaders.

"We need to be diligent in the war against weeds and go after them aggressively," says Tim Butler, manager of the Oregon Department of Agriculture's Noxious Weed Control Program. "Part of the process is educating people about the problems invasive weeds cause and what role they can play. The public can help us look for these weeds and avoid unwittingly spreading them to uninfested areas."

This year’s theme for Oregon Invasive Weed Awareness Week is HELP– which stands for habitat, environment, and land protection. The key message is that the public can help protect the state’s wildlife, natural environment, and agricultural lands by controlling invasive weeds.

“We are working at multiple levels throughout the state to prevent and control invasive weeds,” says Butler. “The week and the governor’s proclamation are good ways to get information in front of the public so that everyone understands they have a vested interest in protecting our natural resources.”

Invasive weeds reduce biodiversity and displace native plant and wildlife species. They invade agricultural land, forests, and other natural areas causing severe production losses, increased control costs, and negative impacts to watersheds and ecosystems. One weed alone– Scotch broom– causes $47 million in losses annually.

"All the regions of Oregon– from the coast to the Idaho border and all points in between– have invasive noxious weed issues they are trying to deal with through many partnerships," says Butler.

As part of Invasive Weed Awareness Week, ODA is highlighting cooperative efforts to address noxious weeds in each of the state’s geographic regions. In all cases, it has taken teamwork and the help of numerous cooperators to identify and attack these unwanted plants.

Northwest Oregon: Goatsrue, Galega officinalis, was discovered in 2011 in three different locations around the Portland metro area. A major problem in Utah and a federally listed noxious weed, this was a new invasive species for Oregon. The first infestation was discovered by a Portland Water Bureau employee, who noted that the plant's unusual tenacity to spread prompted her to inform ODA. Plant samples were submitted to Oregon State University for verification. That led to a discovery of an older sample stored at OSU originating from an infestation in the Tualatin area. Further networking identified goatsrue on Portland Parks and Recreation Department property. Within two weeks, three infestations had been discovered thanks to strong communication between managing agencies. ODA and various cooperators have developed a statewide management plan to stop the spread of the noxious weed and achieve eradication. Cooperators and ODA plans are to survey the location during the 2013 field season.

Southwest Oregon: The eradication campaign against yellowtuft alyssum, Alyssum murale and Alyssum corsicum, aims to protect unique habitat in Josephine County. The Illinois Valley contains the largest concentration of serpentine soils in Oregon that support a diverse and unique flora. In the 1990s, a private company attempted to use yellowtuft alyssum to extract nickel from the soil. Before long, Alyssum escaped from planted fields onto adjacent lands and even onto river bars of the Illinois River. Since being listed as a noxious weed five years ago, more than 90 percent of plants from the original fields, as well as escaped sites, have been eliminated. What used to look like a sea of solid yellow at the Illinois Valley Airport is now only scattered alyssum plants with many native species returning. Partners, including the US Forest Service (USFS), Bureau of Land Management (BLM), The Nature Conservancy, and private landowners are considering native reseeding at the airport later this fall.  Targeted-efforts to protect this valued habitat appear to be paying off.

Central Oregon: Efforts are underway in Sherman and Wasco counties on the lower Deschutes River to restore and protect wild sheep habitat. With grant funding from ODA, the Oregon Foundation of North American Wild Sheep, BLM, Oregon Department of Fish and Wildlife, Oregon State Parks and Recreation, Wasco Soil and Water Conservation District, Sherman County, landowners, non-profits, and volunteers are treating and removing weeds to restore the native vegetation. Once the competitive invasive weeds are removed, native vegetation can reestablish. Not only do the sheep benefit, so do salmon, steelhead, and other endangered species. Purple and Iberian starthistle (Centaurea calcitrapa and Centaurea iberica) have limited distribution in Oregon but can potentially invade 1.5 million acres with impacts exceeding $12 million per year. Only five sites have been documented. In 2009, a nine-acre pasture just south of Spray in Wheeler County was found. Several plants were discovered in the flood plain of the John Day River. The area was treated within a day of being found. An additional 4,500 acre survey over the past three years confirms no new sites have been found.

Eastern Oregon: Dalmatian toadflax, an invasive rangeland weed of the western US, has infested millions of acres since its introduction in the early 1900s. It appears success is on the horizon. The toadflax stem weevil, Mecinus janthinus, is a biocontrol introduced in Oregon in 2001. The good bug has been recovered at many locations in central and eastern Oregon and provides excellent control of the weed. Redistribution of these biocontrol agents has been an effort of BLM, USFS, and county weed control programs. ODA is monitoring the distribution and impact of the stem weevil and moving them to other infested areas.

There have been successes in the fight against invasive noxious weeds in Oregon. But there will never be an end to the war. The upcoming special week may bring some attention to the cause, but it may take 52 weeks a year to truly make a difference.

For more information, contact Tim Butler at (503) 986-4625.


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