“A lot happens once a fire starts burning," said Lucas Harris, a postdoctoral scholar in geography at Penn State. "Crews on the ground remove vegetation and construct fire lines, and planes and helicopters drop flame retardant to stop the spread of the fire. In this study, we measured the effectiveness of suppression operations and previous prescribed fires on fire severity, which is something that really hasn’t been done before.”
The researchers measured tree mortality in Lassen Volcanic National Park, California, one year after the 2012 Reading Fire burned more than 28,000 acres in the park and nearby communities. They combined this data with data on fuels, vegetation and previous prescribed fires, and they worked with fire managers to reconstruct the suppression operations that took place during the fire.
The researchers classified the fire suppression operations as being of low, moderate or high intensity and ran computer simulations to determine tree mortality rates in the forest with and without operations. They ran similar computer models to measure the impact of prescribed burns. They report their findings in the International Journal of Wildland Fire.
The scientists found that in areas with moderate to high operations intensity, suppression operations reduced tree mortality by 22%. Also, prescribed fires reduced tree mortality by 32%. The combination of prescribed fires and suppression operations, however, reduced tree mortality by 72%.
