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Fungus May Halt Advance of Invasive Weed

August 23, 2007

SPOKANE, Wash. (AP) – A fungus scientists have dubbed “Black Fingers of Death” may turn out to be the first long-range weapon in efforts to halt the advance of cheatgrass, a destructive invasive weed, scientists say.

Gonzaga University biology professors Julie Beckstead and David L. Boose were recently awarded $247,000 in federal grants for a three-year study on pyrenophora semeniperda, a tiny, naturally occurring soil fungus that attacks the seeds of cheatgrass.

Working with colleagues at Brigham Young University and the U.S. Forest Service’s Rocky Mountain Research Station in Provo, Utah, Boose and Beckstead hope to gain a better understanding the fungus, including its effect on native plants.

“We’re really excited about the potential of this organism,” Beckstead said.

“The need to replant burns and replace cheatgrass is huge,” she said. “If we don’t do something, there will be more and more cheatgrass and more and more fires.”

Cheatgrass, native to the steppes of Russia, infests about 100 million acres of the American West. Its prickly seeds get stuck in socks and animal fur, but the invasive weed does much greater damage by crowding out native grasses, shrubs and flowers and providing explosively dry fuel for massive wildfires.

The sagebrush grasslands of the Columbia River plateau were swept by fire every 40 to 120 years, but the advent of cheatgrass, which begins growing early in the spring and is the first to dry out in the summer, has increased the wildfire frequency to about every five years, said Pamela Camp, a Bureau of Land Management botanist in Wenatchee.

The fires, in turn, clear more space for cheatgrass to spread in following years. Camp said 2 percent to 12 percent of the state’s native Columbia shrub-steppe grassland remains intact, and restoring cheatgrass-infested areas costs $500 to $1,000 an acre.

“It has a serious impact on grazing and forage production for wildlife,” said Robert Troiano, a BLM natural resource specialist in Spokane.

Herbicides attack only the plant, not the dormant cheatgrass seeds in the soil, and can drift and cause damage to nearby crops and range land, Troiano noted.

In 1992 Beckstead noticed a dark, fingerlike fungus poking out of cheatgrass seeds. She discovered that it kills the seeds, then sends out black, stubby tendrils loaded with spores, hence the nickname.

“We had to call it something,” she said.

The fungus is found on cheatgrass seeds across the West but is more common in some areas than others. Within 10 years it may be possible to grow large quantities of the fungus to spread across infested sites, Beckstead said.

Information from: The Spokesman-Review, http://www.spokesmanreview.com




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