BLACK HILLS PIONEER PINE BEETLE SERIES
October - November 2011
Fire hazards presented by a beetle-killed tree B" M$%& V$(G*%+*( Black Hills *ioneer
Fire has always been a reality in the Black Hills, like the Grizzly Gulch Fire of 2002, shown here in its early stages. While not connected to the Grizzly Gulch Fire, officials said the pine beetle infestation increases the risk of severe, widespread fire in serious ways. Pioneer file photo
PINE BEETLES Continued from -age 10 few beetle-hit trees in the forest before they multiply. He added that in cases of fire in gray, bare “snag” “We've taken a lot of steps to mitigate the amount stands, the conditions become so extreme that fireof fire haFards to Lead,” Stahl said. “The key to fighters won't even enter the area, even if it's threatthose bug trees is to get them out of the forest. \ou ening a home. can't Rust leave them lay there.” In that case, officials said it's the responsibility of Of course, on the other end of all forest fires is the every Black Hills resident to protect themselves from capability of a forest to regenerate. In a lot of ways, potential fire. fire benefits the environment and gives the forest a “I'm advocating that we get prepared for the worst chance to reset. Areas in the \ellowstone !ational — protect our citiFens by doing everything we can to Forest that were scorched by fire several decades ago prepare for the big fire that will certainly come,” are now growing vibrant, healthy trees. Stiger said. “It's a big RobX it's something that's going Though pine beetles did not infest to be with us a long time. We're Rust \ellowstone, studies show that beetle infesgoing to have to face it, accept it and tations don't affect a forest's regenerative prepare for it.” capabilities down the road. Carroll said that while the Forest But that's only part of the issue. The other Service's policy is to immediately and side of the coin, Stiger said, is that people aggressively establish perimeter control live in the forest now. Homes and communiaround wildfires, the resources to do not ties are located right in the midst of these exist to put a fire truck at every home in fire haFards. the Black Hills, so everybody has a perAlthough the forest may eventually benesonal responsibility to look after themfit from a large-scale fire after a few selves, particularly in the first Y00 feet decades of regrowth, then, we also need to around their homes. Mike consider our own safety. Locally, some citiFens are already Stahl Said Stiger, “There isn't a wildland fire preparing for a potential fire. Programs anywhere in the country that's worth a perlike Firewise in Lead are creating fireson's life, even if you throw in a few homes.” breaks around our communities in preparation for a wildfire. This is the fourth article in an eight5week series Lead City Administrator Mike Stahl, a member of that discusses the effects of the mountain pine beetle Lead's volunteer fire department, said the program on the Black Hills. <e=t week's article will discuss has “absolutely” been a success, though most of the the timber industry and its capabilities in regard to work has been in green areas that were heavily overthe pine beetles. stocked. Send us your comments to newsAbhpioneer.com !ot many pine beetle trees have threatened Lead, or log on to www.bhpioneer.com to post comments Stahl said. About Y0 trees total had to be professionon the stories. ally removed from the South Lead Cemetery, but that has been the largest extent of an attack near the city. [eeping it that way, is a matter of removing the
!ORTHER! HILLS — According to the 7.S Forest Service and researchers at the 7niversity of Montana, the following are the decaying stages of a beetle-killed tree and the fire haFards they present. A healthy tree functions in the fashion of a hydraulic pump, moving moisture and nutrients from the soil to its needles. That tree can be burned, though it is more difficult to ignite than a dead tree. After years of drought, foliar moisture in the tree drops, and various chemicals, oils and resins, which are highly volatile, concentrate in the needles and present a higher risk of fire. When a tree is first killed by pine beetles, the beetles chew through the cambian layer of the tree, effectively cutting off its ability to circulate moisture. A study by the 7niversity of Montana indicated that when the moisture drops to about K0 percent moisture, trees will exhibit “extreme fire behavior.” In this and following stages, fire embers burn longer due to the moisture changes. As time goes by, the green needles dry out and turn red. Those needles burn quickly, explosively, and for short durations. Frank Carroll, of the 7.S. Forest Service, said needles like that can be maRor contributors to sweeping, expansive crown fires. Red, burning needles are also easily lofted into the air, and the increased heat from such a fire allows them to be lofted higher and over greater distances, potentially starting spot fires in other locations. Without fire, though, red needles fall to the forest floor within a few years and leave the trees bare, or in the “gray ghost” state. Sray ghosts, both standing and on the ground, contain about T to U percent moisture, which will increase a fire's intensity when they burn. When a crown fire reaches stands of bare trees, called snags, it usually drops to the ground. Fire can then burn along the forest floor, through the dead needles and down trees, and gray ghosts catch fire like firewood. Large, plate-siFed embers will be lofted from gray ghosts and carried for long distances. Additionally, standing gray ghosts aren't very sturdy, and are prone to snap unexpectedly and crash to the ground as they burn. For that reason, firefighters will not enter a fire in a snag full of gray ghosts, even if it's near a home — which is why the Forest Service strongly encourages homeowners to tend the area around their homes for potential fire risks.
Whether standing, bare, or on the ground, beetle-infested trees present unique fire hazards at all stages. Pioneer photo by Mark VanGerpen
Pine Beetle Series