Saturday, December 8, 2012

Invasive Grass Linked to Increase in Wildfires

            Scientists are alarmed by the global increase in the amounts of large, devastating wildfires. Few areas on the planet have suffered as much from wildfires as the western United States and it has not been spared by the current trend. The results of a recent study now indicates that an invasive species is likely responsible for the increased size, ferocity, and frequency of wildfires that have consumed this region.
            The invasive grass species, known as cheatgrass, was introduced to North America by soils inadvertently transported across the ocean by trading ships and then was spread west in the 1800s by pioneers and ranchers. It now covers much of a 600,000 sq km region of western America known as the Great Basin. Cheatgrass is named for its ability to "cheat" by grow incredibly fast in the very early part of the season, staking claim to the soil's nutrients before other grass species have a chance. Early growth results in quick maturation to seed dispersal and then death. Once the grass dies, it becomes extremely dry and vulnerable to igniting. This results in large wildfires that can ignite on cheatgrass and spread rapidly while native species are still green and wet, greatly expanding the length of the fire season. Additionally, by destroying native species before they have completed their maturation, the fires actually help the cheatgrass spread and outcompete other grasses.

            These facts have made cheatgrass a long suspected culprit in the increased frequency of wildfires. Scientists tested the connection by using, "satellite imagery from NASA to compare burnt areas with regions where cheatgrass dominates.". The study further solidified the link by determining that since 2000 nearly 80% of large fires, ones over 100 sq km,in the Great Basin have been fueled mostly by cheatgrass.

            Their suspicions confirmed, scientists are now focusing on how to remove or eradicate cheatgrass from the region. There are several current proposals, one simply calls for physically removing the invasive species while another proposes that a fungus be introduced that will attack and kill cheatgrass seeds. No matter which direction experts decide to go in, it is important that they stop the spread of cheatgrass and facilitate its demise. Otherwise, we very well could continue to see a rise in the range and frequency of destructive wildfires in the western United States.

Link to article:

McGrath, Matt. "Wildfires Fanned by Invasive Grass Species." BBC News. BBC, 12 June 2012. Web. 06 Dec. 2012.

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