Invasive Grass Species Linked to Biggest US Wildfires
December 11, 2012; 1:06 AM
Researchers found that a non-native species of grass in the Great Basin fueled some of the largest U.S. wildfires in the West.
A research team that included members from the Pennsylvania State University, University of Massachusetts-Amherst, University of California-Santa Barbara and University College London studied satellite imagery over a period of 10 years to learn how cheatgrass has changed the fire activity across the Great Basin, according to live.psu.edu.
The team found that the grass influenced 39 of the 50 largest wildfires during the last decade. Cheatgrass can spread rapidly and fill in the ground between other plant species. As a result, areas where cheatgrass fires have occurred have a shorter fire-return interval (the time between fires in a region) than other native plant species.
Cheatgrass was accidentally introduced to the area by settlers to the West during the 1800s. The grass grows during the wet seasons and is very dense. Currently, the grass is covering an area larger than 40,000 square kilometers (more than 24,000 square miles), an area more than 100 times the size of Salt Lake City, Utah.
The average size of fires involving cheatgrass grasslands in the Great Basin area was significantly larger than fires in areas that were dominated with other plants such as pinyon-juniper, montane shrubland or agricultural land.
Cheatgrass fires over the last decade have affected parts of Nevada, Utah, Colorado, Idaho, California and Oregon.
The researchers are looking at possible solutions to the cheatgrass problem, including using a fungus to attack the grass seed, the BBC reports.