EUGENE, Ore. -- After hiking in Oregon, a University of Oregon plant biologist suggests, people may want to brush off their shoes and comb through their dogs in an effort to curb the spread of an invasive grass that is expanding its range.
The grass is false brome (Brachypodium sylvaticum), a native of Europe and Asia, which likely landed in Oregon by way of USDA experimental plots in 1939 near Corvallis and Eugene. This grass likely was brought in, along with other grasses from around the world, to test as a range-improvement crop, but in the test plots the genotypes crossed to create "a little monster" hybrid, according to research published in 2008 by Mitchell Cruzan of Portland State University. The grass escaped and is found today across Oregon, north to south from Astoria to Grants Pass and from west to east from the coast to near Madras, but mostly it is concentrated in the Willamette Valley.
Bitty A. Roy, a scientist in the UO's Institute of Ecology and Evolution, studies the ecology of false brome. In two new studies, Roy and colleagues report that the grass is somewhat controlled in its native Europe by two pathogenic fungi (Claviceps purpurea and Epichoe sylvatica), which block reproduction, but its only known and less-lethal enemies in Oregon are insects.
The National Science Foundation-funded research is detailed in separate papers in the journals Ecology and Mycologia. The findings, Roy said, provide support for the "enemy release hypothesis," which says invading plants are free from the enemies of their native habitats. But, she added, they still fall prey to local generalists such as herbivores in the areas they invade.
Roy and colleagues studied 10 sites in Oregon and 10 in Switzerland to determine what damages are inflicted on the grass by fungi, insects, mollusk and deer. In Switzerland, they found more kinds of enemies, but the biggest ones were generalist mollusks and t
|Contact: Jim Barlow|
University of Oregon