SOS Forests

Another Post-Fire Cost-Plus-Loss Case

In the previous post we pointed out (again) that forest fires cause losses (damages) far in excess of suppression costs. Moreover, some of those losses continue to accrue long after the fires are out.

One of our favorite SOSF operatives sent us yet another example. The Sawtooth National Forest has proposed spraying a bark beetle repellent to save trees on Bald Mountain (site of the Sun Valley ski area) because a bark beetle infestation is expected following the 2007 Castle Rock Fire (48,000 acres) [here, here, here, here].

It won’t be cheap, and it may not be successful in preventing yet more damage to the forest. The repercussions from that fire, like so many others, just keep on coming.

From the Sawtooth NF Projects and Plans website [here]

United States Department of Agriculture Forest Service
Sawtooth National Forest, Ketchum Ranger District

File Code: 5140/1900-1
Date: December 4, 2009

Scoping Notice for the Bald Mountain Douglas-fir Bark Beetle Project

Dear Interested Public:

The Sawtooth National Forest - Ketchum Ranger District is seeking your input on an important project proposal for the Bald Mountain ski area. (See Figure 1, Insect Survey Map)

The 2007 Castle Rock Fire burned approximately 48,000 acres of Sawtooth National Forest and Twin Falls District-BLM public lands including the southern and western edges of the Bald Mountain ski area. The wildfire didn’t completely kill all the trees within its perimeter, but left hundreds of thousands of fire-weakened trees, mostly Douglas-fir, struggling to survive on the landscape. Many of these stressed trees have now become the perfect host for a variety of insects including the Douglas-fir bark beetle (DFB), which will soon kill them.

Our entomologist’s Forest Health Protection Biological Evaluation can be found [here]

DFBs are found naturally in most Douglas-fir stands but at such low levels they typically kill only a few trees every year. However when the right environmental conditions exist, as are occurring now in the aftermath of the Castle Rock Fire, their population can explode. …

The greater danger though, is that the exploding population of DFBs emerging from these now-dying trees will infest and overwhelm the natural defenses of otherwise healthy, green Douglas-firs outside the perimeter of the Castle Rock Fire, including Bald Mountain.

Post-Castle Rock Fire insect surveys conducted in the summer and fall of 2009 show Douglas-fir beetle populations are robust west of the ski area as well as in the green tree stands between ski runs and burned areas along Guyer Ridge on the upper half of Warm Springs. The beetles have already infested a large portion of the trees over 20 inches diameter along Guyer Ridge. Many of these already-infested Douglas-fir will likely turn red during the summer of 2010. Healthy Douglas-firs nearby are in jeopardy of becoming infested by beetles next spring, simply because of their susceptibility and proximity to exploding populations of beetles.

We are now proposing to reduce additional DFB-induced post-fire mortality of large, surviving Douglas-firs by treating vulnerable tree stands with a two-pronged counterattack. The proposed action is to: 1) disperse anti-aggregant pheromones (via aerial and ground application) that signal beetles this area is already occupied, and; 2) bait beetles away from ski runs, thus avoiding a lethal build up of bark beetle populations within and adjacent to this portion of the Castle Rock burn area, including Bald Mountain.

Pheromones are naturally-occurring chemicals that insects produce. Insects use pheromones to communicate with one another. Methylcyclohexenone (MCH) is the anti-aggregant pheromone DFBs produce to tell other DFBs “this tree is full – find another tree to infest”, and has been manufactured for use as a bark beetle repellant for more than 20 years. According to the EPA fact sheet, [here], tests on MCH show it has very low toxicity. There have been no reports of adverse effects to humans, animals, or the environment from use of MCH as a beetle repellent. …

Other options for managing this DFB outbreak, such as salvage logging the thousands of already-infested Douglas-fir, and cutting then removing “trap trees”, would be impossible to complete within an operating ski area before the next generation of beetles emerge next spring and would likely meet much public opposition. DFBs natural predators such as certain wasps and other beetle species are able to help keep low, endemic levels of DFBs in check, but have never been shown to control an outbreak such as began occurring in the Castle Rock Fire area in 2009. Funnel traps alone will not trap every emerging DFB next spring. Exclusively using ground application of MCH pouches for the thousands of acres needing protection is slow, laborintensive, potentially hazardous for the applicators due to Bald Mountain’s steep topography, and prohibitively expensive.

We believe the best option for protecting Bald Mountain’s remaining uninfested Douglas-firs is helicopter dispersal of MCH flakes. A contract for this service needs to be awarded prior to DFBs emerging in late-April. Federal contracts typically take 65 days or more to advertise and award. Therefore, a decision on this proposal needs to be made by mid-February 2010.

Your questions and comments regarding this proposal are an integral part of the planning process. They will help determine what issues and concerns need to be considered as we plan for this project. Comments are most helpful if received by January 8, 2010. All comments received in response to this solicitation, including names and addresses of those who comment, will be considered part of the public record on this proposed action and will be available for public inspection. … [more here and here]