Beetle Kill 2009: Commonly asked questions answered by the Forest Service |

Beetle Kill 2009: Commonly asked questions answered by the Forest Service

Q. What is the Mountain Pine Beetle?

A. Mountain Pine Beetles are an insect about the size of a grain of rice. These beetles bore into mature trees usually over five inches in diameter. They lay their eggs and introduce spores of blue stain fungi that grow in the tissues of the tree. Beetles in the larval stage feed on the tissue with transports nutrients to the tree. The fungus and the feeding interrupt the flow of water, decrease sap flow and ultimately kill the trees. When the larvae matures into beetles, they fly to the next tree and start over. In Grand County, MPB infests predominately mature lodgepole pine in epidemic proportions.

Q. I was surprised at how many trees were removed in the Arapaho National Recreation Area (ANRA). Was this really necessary?

A. We have been spraying high-valued trees since 2002. Despite these efforts, successful beetle attacks have occurred each year. As trees have been attacked by the beetle, we have removed them. This has resulted in low-density stands of lodgepole pine in many areas. Typically, lodgepole pine grows in high densities, which protects this shallow-rooted species from high winds. When more than 50 percent of the trees have been removed, those that remain are more susceptible to being blown over by the wind. Because of our concern for visitor safety, it was necessary to remove almost all the trees in the Stillwater Campground, Green Ridge Campgrounds, Arapaho Bay’s Moraine Loop Campground, Cutthroat Group Campground and Point Park Picnic Area. Select hazard trees were also removed in Arapaho Bay’s Roaring Fork and Big Rock Campgrounds, Hill Top Boat Launch, Pine Beach Picnic Area and Meadow Creek Reservoir. Trees will continue to be removed to protect public safety as necessary.

We know this is a big change for these areas and have begun replanting trees. Last fall, volunteers participating in National Public Lands Day (NPLD) planted 3,000 seedlings in Green Ridge Campground. Tree planting is planned this spring for Point Park in cooperation with neighbors to the Park and the Town of Grand Lake. We also have plans for more planting this fall on NPLD in the Green Ridge and Stillwater campgrounds. We will continue to seek funding for more replanting in our campgrounds

Q. How will recreation opportunities be affected by all this logging and hazardous fuels reduction?

A. Whether it be through logging, hazardous fuels removal, prescribed fire, or preventative spraying, completing our mitigation work is very important to help us reach our goal of reducing the impacts of wildfire to communities and watersheds. Safety is one of our key components in this effort. As we complete our work temporary closures of campgrounds, trails, roads and other areas may occur. We are committed to keep these closures as small and short in duration as possible. Frequent updates can be found at

You can help us by:

– Driving slowly on roads used by logging trucks. Make sure intersections and roads are clear before you enter them.

– Stay informed about closures and stay out of closed areas. Closures will be marked on our maps in red and on the ground. Our closures will be enforced.

– If you find yourself near logging activity, you are in the wrong place. Please exit the area immediately.

– You can also help by staying on the trail and giving new trees time to get established.

Q. Will the spraying of insecticide on trees pose a threat to people or wildlife?

A. When used in a safe manner by a licensed contractor, preventive spraying for MPB does not pose a danger to wildlife or people. Preventive spraying of high value trees, with a non-restricted use insecticide like Carbaryl, is effective for about one to two years. The treatment should be repeated annually until the outbreak subsides. When trees are successfully attacked by beetles after spraying it is often because some portion of the tree was not effectively sprayed. Evidence over the past 20 plus years suggests that the materials approved for this purpose have negligible impact on birds and mammals when applied safely. However, the insecticide is toxic to fish and aquatic creatures and care should be taken to prevent spray drift or contact with any water or wet areas. As an extra precaution the Forest Service uses a buffer, or no spray zone, adjacent to all open water. For more information, please contact the Colorado State Forest Service at

Q. Mountain Pine Beetle is a natural part of the forest. Shouldn’t we just let nature take its course?

A. While MPB is endemic to lodgepole pine forests, the current outbreak is at epidemic proportions due to warmer winters and an abundance of drought-weakened, older trees. Active forest management is needed to reduce the fire hazard that red, beetle-killed trees pose to communities in the wildland urban interface. In addition, a high intensity wildfire would severely damage critical watersheds that provide drinking water for local communities, as well as to the Front Range.

Q. How does the mountain pine beetle outbreak change fire behavior and fire hazard?

A. The fire hazard caused by mountain pine beetle-killed trees changes over time. About three to four years after an outbreak, the majority of affected trees will be in the “red and dead” stage. At this time, fire hazard increases because the red needles are very flammable. However, fire hazard decreases substantially once these needles fall off of the trees and leave dead standing trees or “snags.” When the majority of trees fall down, creating a jackstraw effect in the forest, the amount of surface or ground fuels increases fire hazard. If a wildfire occurs after this point, it will be a high-intensity, high-severity ground fire.

Q. If you are logging beetle-killed trees, why is it necessary to burn piles? Won’t this pose a fire hazard?

A. One method of slash removal would be to chip and scatter the chips on site. However, this is more costly. By burning, we can eliminate the woody material that could fuel wildfires in the future. Burning also returns nutrients to the soil. Another method would be to chip and haul the material away on a truck, but currently there is not enough demand for chip material. Hauling is also not economically feasible in most cases. Burning allows us to eliminate the piles in a safe and efficient manner while keeping it economically feasible to continue this kind of work.

Q. Why are you using prescribed fire?

A. Prescribed fire is used remove woody debris from the forest floor under specific conditions. These types of burns can be designed to improve wildlife habitat, and encourage regeneration. Aspen is a species that is particularly responsive to fire and other disturbances and will send up new shoots in response. Prescribed fire helps the forest become more diverse, not just in species but in age.

Q. How long will it take for the National Forest to regenerate and for small trees to begin growing in clear-cut and untreated areas?

A. Natural regeneration generally becomes established three to five years following logging. Because treatments are often concentrated in lodgepole pine areas, this species will dominate the new stands. Pockets of aspen are expected to sprout and expand where aspen was mixed with lodgepole pine prior to treatment. The disturbance from logging will stimulate aspen sprouting at high densities.

Untreated lodgepole pine stands will slowly deteriorate, sometimes taking 15 to 20 years for dead trees to blow down. Natural regeneration will take longer to restock these areas ” at least five to seven years. Due to the slow deterioration process, the forest floor will have more shade and protection than the treated areas. As a result, subalpine fir and to a lesser extent Engelmann spruce will regenerate at higher levels along with lodgepole pine. Aspen is expected to expand where it is mixed with beetle susceptible lodgepole pine as these areas become more open and competition for light, water, and nutrients declines.

Q. How soon after the epidemic can people replant? What species should be planted on private property?

A. Reforestation can begin as soon as logging activities cease to avoid damage to newly planted trees. Trees should be planted in the spring or fall depending upon the type of stock, access and snowmelt. Only native species should be planted when the objective is to initiate a new stand of trees. Favor trees that will grow well in open conditions like lodgepole pine or aspen. Planting more shade tolerant species such as spruce and fir should be more site specific. These trees, and aspen, will have higher moisture requirements than lodgepole pine. Other species such as Ponderosa pine, Douglas-fir, and limber pine occur in Grand County at low densities and should be considered for planting at low numbers only. The best species mix is generally best indicated by the species (including grasses and shrubs in addition to trees) that existed prior to the beetle epidemic. Young lodgepole pine will be a low risk for bark beetle infestation for several decades.