Report: climate, not beetles, main cause of forest fires
A new report by four forest ecologists says climate rather than beetles is the main cause of forest fire risk, and that risk is best addressed by creating defensible spaces around homes instead of logging in the backcountry.
The report, available at http://nccsp.org, was prepared on behalf of the nonprofit National Center for Conservation Science and Policy and is based on a scientific literature review. It questions the worth of a proposed Colorado rule that would allow for limited logging in roadless portions of national forests for purposes that include protecting communities and municipal watersheds from fires and the spread of insects and disease in trees.
Report authors said Tuesday that forests being attacked by beetles in Colorado and other states are naturally dense, and large and severe fires in those forests are the norm. They said drought and warm temperatures are such major factors in creating high fire risk that beetle outbreaks do little to add to that risk.
Dominik Kulakowski, a professor of geography and biology at Clark University in Massachusetts, has studied the relationship between beetle outbreaks and forest fires in Colorado for more than a decade.
He said new research is showing that dry needles of beetle-killed trees don’t increase fire risk, because they fall from trees quickly enough to reduce the total volume of fire-carrying fuels in the forest canopy.
The report authors say that using fire-resistant building materials and clearing brush around homes are more cost-effective protections from wildfire than backcountry logging, which also can cause negative environmental impacts.
Logging potentially can increase fire danger by removing standing dead trees used by insect predators such as birds, and by compacting tree roots and adding to water stress, they say.
Joe Duda, forest management supervisor for the Colorado State Forest Service, said while doing fire mitigation work around homes is important, it also can be important to do nearby forest thinning, so firefighters can safely make a stand to defend those homes.
Protecting power lines and other things that matter to a community can be important as well, he said.
Also of concern is that when insect-killed trees fall but have yet to begin to rot, the downed timber could help fuel more intense, longer-burning fires, Duda said. That could damage soils and burn up seed cones rather than just causing them to open, as occurs with fires that move quickly through the crowns of standing trees, he said.