Friday, November 11, 2016

Scientists try bacteria to halt invading cheatgrass in West

It sounds like science fiction: An unstoppable invader is taking over the West and the best hope to stop its relentless advance is a small team of anonymous scientists. But that's what is happening in southwest Idaho, where experiments are underway to determine if soil bacteria can halt the century-long assault of non-native cheatgrass, which sends out roots that cheat other plants of water in the spring. "We hope that we can identify the effectiveness of the bacteria on annual grasses and to identify non-target risk effects," said Matt Germino, a research ecologist with the U.S. Geological Survey running the experiments at three scattered sites of about an acre each. Cheatgrass dries out in the summer, transforming into extraordinarily effective tinder for wildfires. The fires then kill competing native plants and destroy habitat needed by cattle ranchers and more than 300 species of wildlife, including the imperiled sage grouse bird. The results are huge, cheatgrass-filled landscapes that serve as fuel for frequent wildfires, some reaching hundreds of square miles. Ann Kennedy, a soil microbiologist with the U.S. Department of Agriculture's Agricultural Research Service in Washington state, has sorted through 25,000 strains of naturally occurring soil bacteria to find a handful that can stop cheatgrass root growth. "In the spring they come up great guns, which then doesn't let that plant grow very well in the spring, or even over winter very well," she said. "You can draw down the seed bank of these annual weeds to where basically they're gone." The strategy is to use the bacteria, possibly with some combination of herbicide, to eliminate cheatgrass long enough so that native plants can get established and fend off cheatgrass themselves...more

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