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Motivating Beetlemania
Seeing the forests through the trees big change in forests has grown in last decade
By Juley Harvey
Friday, April 24, 2009
Caption: Eric Jones and Zach Becker of Rocky Mountain National Park ignite a test tree for wildfire researchers in Little Horseshoe Park on Wednesday. Researchers studied how trees of different stages of death from beetle kill burned. Photo by Walt Hester
ESTES PARK, Colo. The mountain pine beetle, while not necessarily our friend, is just another part of the ecosystem, Boyd Lebeda, a member of the Colorado State Forestry Service, told the Estes Land Stewardship Association at the library recently.
Lebeda said the forest service has had a lot of interaction with the pine beetle and the big changes in our forests over the last decade. These changes are challenging peoples perspectives on forests, but there are meaningful steps citizens may take to help preserve the trees, he said.
There have been changes in every single forest type during the last decade, he said, because of the severity of the drought and increase in wildfires, which created conditions that allowed insects to take advantage and thrive. Not only mountain pine beetles are chewing their way through forests. Pinon and spruce beetles are active, also. Aspen have problems with different pathogens that are affecting them because of the drought and their location. The ash borer (not detected here yet) and the gypsy moth (largely in urban areas) are also among native and non-native heinous insects, Lebeda said.
In aerial surveys done by the forest service, the mountain pine beetles destructive progress has been mapped.
In 2008, we saw a distinct advance through lodgepole pines and ponderosas, he said. A lot of areas have been affected.
Although 2 million acres in Colorado have suffered so far from pine beetle destruction, its worse in Canada. In British Columbia, almost 35 millions acres have been affected. Its a big advance on the continental issue, he said.
The trees that are hit fade over time, as they are affected by the beetle. Its one of the insects signatures. Aerial patterns show the fading well.
The beetle is one of many issues that require Estes Park to have a plan.
We have a plan for mountain lions, bears, mountain driving, snowstorms, neighbors, wind, weeds, wildfire, he said.
The mountain pine beetle is not a new forest thing, Lebeda said. Its part of the ecosystem. Its happening now at a bigger scale. We have to form a plan to respond.
In the attacking adult stage, female pine beetles use pheromones to attract the males and to signal, Im in and The tree is full, he said. As the larvae grow, the tree doesnt change. In the springtime, however, the needles turn yellow and then red. A number of trees dont turn colors until after the beetles have flown. Anti-pheromone packages have been tested to deter the beetles, but they dont do as well at higher elevations, Lebeda said. They could be used in conjunction with a larger deterrent, he added.
One way to know if a tree has been affected is by observing the trunk for pitch tubes, popcorn-shaped masses of resin that form on the trunk after the beetles tunneling begins. Also, they will leave boring dust in bark crevices and on the ground immediately adjacent to the tree base. Lebeda said you can chop back the bark to observe the eggs and larvae, to determine the scale of the attack, and to kill the beetles.
For short-term control, the forest service recommends spraying, covering, burning or peeling infected trees to kill the beetles. Preventive sprays can protect green trees that have not been attacked. For a long-term remedy, the forest service advises thinning the stands of trees, to leave well-spaced, healthy trees in the area. During the early stages of an outbreak, the most susceptible trees are those under stress from injury, poor site conditions, fire damage, overcrowding, root disease or old age. As beetle populations increase, most large trees in the outbreak area may become endangered.
Lebeda said the massive outbreak has occurred now because of drought and the conditions of the forest.
Many old lodgepole pines here date back to the 1800s, he said. They grew up together, at the same age and rate. A beetle attack among them affects a whole other generation of trees. An example of regeneration after such a catastrophe is Yellowstone, where there is now a sea of new lodgepoles, after the fires of the 1980s, he said.
The ponderosa pine and lodgepole forests at lower elevations are denser than they were 100 years ago, Lebeda said.
There were a lot fewer trees in 1901, he said. The forest was more open. There were not a lot of fires or disturbances.
Although mountain pine beetle epidemics in the 1960s killed many trees here, there was more diversity and age structure in the forests then, he said.
I believe that makes the forest more resilient, he said. Ecologically, its time for a big change, whether we like it or not.
In Grand County, the old trees are dying and a new forest is being born.
The aspen will do really well, Lebeda said.
Think of the forest mix like a stock portfolio, he suggested. Where theres diversity, theres a better chance for survival.
Thats why the ponderosa and mixed conifer are doing better, he said.
Since lodgepole pines may live from 100 to 200 years, if there were no fires or beetles, the trees would die of old age and fall down, creating a real heavy fuel loading, he said. Within time, the forest would regenerate and eventually burn, because of the fuel available. If not by fire, the trees would be attacked and the beetles would come and take them. Thats what they do.
Fuel-reduction treatments have a positive effect on forestry health, making the trees more resilient, he said.
So, how can we grow and preserve healthy trees? Practice defensible space, Lebeda said.
It works, when its done, he said. The forest is thinned, it protects from wildfires and its safer.
Defensible space involves creating an area where fuels and vegetation are treated, cleared or reduced to slow the spread of disease or wildfire. It provides room for firefighters to do their jobs.
Remove stressed, dead or dying trees and shrubs. Thin and prune remaining trees and shrubs. Extend thinning along your driveway to the main access road.
Maintain trees and shrubs so there is at least 10 feet between crowns.
Mow grasses to keep them low, a maximum of 6 to 8 inches tall.
Dispose of slash (limbs, branches and other woody debris) through chipping or by piling and burning. Contact the forest service for information about burning slash piles.
The forest service says that the healthiest forest includes trees of multiple ages, sizes and species, with adequate growing area over time.
If you find a beetle-hit tree on your property, have the tree cut down and the wood removed and taken to an air curtain burner, Lebeda said. They are designed to burn the wood and kill the larvae. Also, a debarker on a chainsaw may be used, but its labor-intensive.
Finding infected trees in the fall provides time to treat the trees.
Timing is everything, he said.
If you find an infected tree in September, Lebeda recommends cutting it into lengths, letting it dry out thoroughly at the same elevation and then using it as firewood and the beetles will die. If property owners consider covering the cut trees with plastic, they should use several layers, as the beetles can chew through one layer.
Preventive spraying of insecticide on the tree bark is useful when the females are flying, he said. The insecticide tastes bad and deflects the females from landing on the tree trunks. Its effective, but not used on a forest-wide level, although the forest service has been spraying in campground areas.
Its necessary to spray every year during an epidemic. Make sure birds are not nesting during the treatment. Property owners may spray as late as June, he said.
This epidemic might be more aggressive than previous ones, he noted.
Its not an epidemic we could control, because of the native insects involved and the massive nature.
Its wise to protect places and ensure we go through it and come out better, he said. Thinned stands will fare better. Its a resilient system over 30 years. If we have the perspective of 30 days, well think its bad. If you look at it with a longer perspective, the forest is going to be here.
Beetles are always around. Theyre an endemic population. They force us to work with our neighbors to reduce the local population of beetles and remove infected trees. Landowners are the best hope. Theres a wildfire hazard when the trees turn red. Our epidemic has taken longer (to develop) over a smaller area than Canada. The Canadian event was very abrupt compared to ours. There was a cloud of mountain pine beetles. Thats probably how we got them in town. The wind disbursed them, he said.
Red needles may stay on the infected trees for three years before dropping and adding to the fuel load. In areas where new forests try to grow up through heavy fuel loading, a lot of hot, fast fires may be expected.
They are hard to control. Firefighters are working among falling trees, he said.
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