Pennsylvania State University

ScienceShot: Invasive Grass Behind Largest Wildfires

An invasive grass species has sparked the interest of researchers studying the ecology of wildfires in the western United States. Cheatgrass, a long-stemmed plant native to Europe and southwestern Asia that was introduced by settlers in the 1800s, is now common in Nevada, Utah, Colorado, California, and Oregon. By comparing satellite images of cheatgrass to fire activity in the same area, scientists have now shown that the grass is involved in a disproportionate number of fires in these regions, and those fires were among the largest. Although cheatgrass makes up only 6% of the area's vegetation, it has been involved in 39 of the 50 largest fires in the last decade, and has burned twice as much as any other plant species, the team reports this week in Global Change Biology. The grass's ability to spread rapidly and to thrive in a wider variety of climates than other native plant species may contribute to its fire activity, researchers say. By understanding the life cycle of cheatgrass and its relationship to fire activity, climate, and other vegetation, they hope to predict, control, and prevent future wildfires—and effectively cheat the invasive plant out of its evolutionary advantage.

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