Community Agriculture Alliance: Falling trees have far-reaching effects on the Routt National Forest
January 16, 2014
Now that a decade-plus has passed since the Routt National Forest began experiencing its heaviest bark beetle impacts, Routt County residents and visitors can expect to see increased numbers of falling trees.
According to Medicine Bow-Routt National Forests Timber Program Manager Mark Westfahl, the expectation has been that most beetle-killed trees would begin falling in large numbers within eight years of succumbing to beetles. This estimation, of course, has a number of variables, including soil type, slope and exposure to wind. On wind-swept slopes, even healthy stands of trees are inherently vulnerable to wind-throw. Conversely, we have seen dead trees stand beyond eight years where they are protected from strong winds.
The following explores what falling trees might mean to you or someone you know.
For those working in the forest products industry, the scale and timing of falling trees can influence the types of products generated by various markets. While opinions vary about the "lifespan" that beetle-killed trees will have for producing viable forest products, this ultimately depends on the type of product being processed.
As a general rule of thumb, depending on their size, standing dead trees will remain viable for producing saw-timber (boards) for several years before becoming excessively cracked from drying. Foresters on the Routt National Forest have observed saw-timber viability for five to eight-plus years. Once trees fall, as long as they are not in direct contact with decaying organisms on the ground, they can remain viable for biomass products for several more years.
Fortunately, there are a number of traditional saw-timber mills and biomass facilities, such as pellet mills and electrical cogeneration plants, available for the Routt National Forest to partner with in removing dead materials.
Falling trees also can impact the bottom line for livestock producers permitted to graze their animals on national forest land. Grazing allotment fences used to manage the distribution of permitted livestock are required to be routinely maintained by permittees as a condition of their permit. More than 100 fence miles are threatened to some degree by falling trees on the national forest, though the extent and severity of this threat varies by location. Forest managers and permittees currently are seeing impacts on about half of these miles, and collaborative efforts to address down trees are ongoing. Forest managers also are looking ahead for solutions on how to address potential longer-term range management challenges presented by falling trees.
If you recreate in the Routt National Forest, safety is your concern and you need to remain vigilant of falling trees before and during every outing. It's estimated that an average of about 100,000 dead trees will fall each day on the Medicine Bow-Routt National Forests for the next decade or so. Winter recreationists are encountering increased numbers of down trees on groomed trails, and blow-down is expected to increase with late winter/early spring winds. The average dead lodgepole pine tree weighs about 1,000 pounds and can fall without warning. It's critical that you look up and around and be continuously aware of your surroundings to reduce your exposure.
Don't park under dead trees, and stay out of the forest on windy days. You are ultimately responsible for your safety.
Although widespread tree mortality has occurred, as we move beyond the beetle epidemic, we are beginning to learn that the overall mortality level in individual stands may not be as high as initially anticipated. We expected about a 90 percent mortality in lodgepole pines greater than 5 inches in diameter, and while this level generally has occurred in trees larger than 9 inches diameter, smaller trees have fared better. Preliminary results from recent examination of some stands by Routt National Forest employees indicates that mortality may be as low as 40 percent for trees less than 5 inches and about 60 percent in trees between 5 and 9 inches. This could be our silver lining as we move forward with this newly reshaped forest.
Larry Sandoval is the public affairs officer for the Medicine Bow-Routt National Forests.