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Mon May 13, 2013
Study: Grazing Helps Invasive Cheatgrass To Flourish
A new study out of Oregon State University suggests that overgrazing could be helping an invasive grass to flourish. That differs from previous studies that have found grazing can better manage that plant — cheatgrass — which threatens rangeland habitat.
The invasive plant cheatgrass can increase the frequency and severity of rangeland fires.
The study found when livestock and wildlife overgraze rangeland, they can trample soil and thin out native bunchgrasses. The authors say that creates bare spots, or gaps, between the sagebrush and bunchgrass. Those bare spots are where cheatgrass thrives.
Paul Doescher is one of the study’s authors.
“In our study, we looked at these multiple factors, and they all kind of pointed toward this one recognition: that the gaps between the native grasses, when those increase past a certain point, those factors lend themselves to the invasion of this weed,” he said.
Doescher said the study does not suggest cattle should be removed from rangelands.
Instead, he said, ranchers can pay “really careful attention to the timing, and the frequency, and the intensity of the grazing on the site. And there’s a lot of ranchers that do this already.”
Other studies have suggested that grazing can help reduce cheatgrass growth. But Doescher says the Oregon State University study found more cheatgrass in heavily grazed areas.
Doescher says more study is needed to determine how big the bare spots in native grasses have to be for cheatgrass to flourish.