Livestock Can Help Rangelands Recover from Fires
By Ann Perry
September 30, 2009
A 14-year study by Agricultural Research Service (ARS) scientists in Oregon found that rangelands that have been grazed by cattle recover from fires more effectively than rangelands that have been protected from livestock. These surprising findings could impact management strategies for native plant communities where ecological dynamics are shifting because of climate change, invasive weeds and other challenges.
Much of the rangeland in the western United States is threatened by the spread of cheatgrass and medusahead, invasive non-native annual grasses that fuel wildfires and readily infest landscapes, especially after fires. These rangelands historically were burned by wildfires every 50 to 100 years, but over the past century these fires have been suppressed by humans. This suppression allowed some dead plant litter to accumulate, but when cattle were introduced to the region, their grazing helped keep litter accumulation in check.
The scientists conducted a controlled burn on all the sites in 1993, and then measured vegetation cover, vegetation density and biomass production in 2005, 2006 and 2007. They found cheatgrass had infested a large portion of the ungrazed sites, leaving these areas even more vulnerable to future fires.
However, cheatgrass did not become problematic on the sites that had been grazed. On these sites, native bunchgrass cover was almost twice as dense as bunchgrass cover on the ungrazed sites. The team concluded that the litter in the ungrazed sites fueled hotter fires that killed off much of the perennial vegetation, which allowed quick-growing invasive annuals to become established. Read More
A healthy grassland is a properly grazed grassland. Not only do livestock reduce the risk of catastrophic wildfires, but this study shows that it helps them recover when fire does occur. Not only does grazing keep our grasslands healthy, but it allows us to utilize this great natural resource by having livestock convert these grasses into a usable protein source for humans.