CORVALLIS – The spread of noxious, exotic (non-native) weeds in Oregon costs the state millions of dollars annually in lost economic productivity and resources spent on weed control programs. Researchers at Oregon State University hope to enlist the help of landowners and land managers throughout the state in the war on weeds via an online-based weed information exchange called Weedmapper. See it online at www.weedmapper.org.

“The idea behind Weedmapper is to provide agency officials, land managers and Oregon landowners with quick and easy access to the latest information available on the location and extent of noxious weed infestations around the state,” said Doug Johnson, a rangeland ecologist in the OSU Department of Rangeland Resources.

“In addition, Weedmapper is designed to help more people get involved in the weed control effort,” Johnson added. “The site invites any Oregon landowner with Internet access to report sightings of exotic weeds.”

Weedy invaders such as Russian knapweed, scotch thistle, gorse and tansy ragwort cause harm by displacing native plants on forest and rangelands, damaging wildlife habitat and grazing areas for livestock. In addition, some weeds such as tansy are toxic to livestock.

The more widespread invasive noxious weeds become, the greater the damage they cause. For example, tansy ragwort, which is poisonous to livestock, is estimated to have caused economic losses of $5 million annually in Oregon for many years until weed control strategies began to reverse the spread of tansy in the late 1990s.

The database within the Weedmapper web site includes photographs and descriptions of weeds as well as maps.