Douglas Fir Bark Beetle update
June 24 2020
The VCF staff continue to monitor the Fir Bark Beetle and new attacks on the surrounding forests at Swift Creek, 5 Mile Mountain (which include the bike park trail systems) and Pack Saddle. Earlier this Spring the VCF set up four pheromone traps and felled Douglas Fir trees at those sites. The objective is to lure the flying insects into these smaller trap areas rather than dispersing their flight over a larger area. At this date the Fir Bark Beetles have doubled in the traps and the surrounding felled and adjacent trees have thousands of ‘hits’ or entry holes. These are indicated by lots of ‘frass’ (fine sawdust) and immediate stress to the tree by loss of needles noted on the forest floor. As the season continues for these insects observations will be made to determine the best time to remove and process these trees to reduce further infestations to the adjacent forests.
The initial observations by VCF staff were that main clusters of trees which were hit occurred along the bike trails systems. The recent bark beetle attacks were generally located around trail development slash piles and felled trees that were left in the forest after being cut down. It is the felled tree debris that attract the flying beetles.
D-Fir Bark Beetle host preference is windfall, old (over mature), stressed, or damaged trees. The beetles fly in the spring from April to July (when the ambient air temperature is greater than 16°C). Females fly first to find a suitable host, and emit pheromones to initiate mass attacks.
The VCF staff continue to work with VARDA to develop better trail development strategies.
Logging has taken place over the 2019 2020 winter season to remove newly attacked dead and dying Fir trees.
Bait (pheromone) has been purchased and will be attached to the funnel traps for the first flight of the Beetles in the Bike Park. The intent is to keep the beetles from dispersing over larger areas.
Current VCF forest health issues include bark beetles, defoliators, pathogens, animal damage, invasive species and abiotic factors such as wildfire damage and drought.
The community forest staff are constantly monitoring the health of the forest in conjunction with the annual ministry forest health flights over our area of the province.
Lodgepole Pine Dwarf Mistletoe
Is a pathogen found in most of our low elevation pine forests. It has caused severe damage to the pine trees and has contributed to the flammability of the dead and dying stands that we see around Valemount.
Infections by these parasitic mistletoe plants retards and deforms growth, reducing seed production and wood quality. Heavy, long-term infections can kill trees prematurely. Dwarf mistletoe induces abnormal tree growth at the point of infection, and produces a structure known as a witches’ broom, which contorts the typical branching structure. Dwarf mistletoes are small, leafless, parasitic flowering plants that kill by slowly robbing the tree of food and water.
In the springtime sometimes you can hear the snapping of the flower as it propels seed into the air. This is how mistletoe spreads seeds to infect new pine seedlings underneath the infected stems and other seedlings nearby.
The first symptom of dwarf mistletoe infection is a slight swelling of the bark at the infection site. The parasite is identifiable when the yellow to green or brownish-green segmented shoots protrude from the infected part of the tree. They form about 2-3 years after the infection.
Partial cutting that leaves mature, infected pine trees standing exacerbates the spread of infection to create a perpetually infected stand. The only way known to break the cycle, is to sanitize the area by clearcutting all pine stems.
Western Gall Rust also infects pine trees and is most often found in young stands and plantations. The stem rust kills the tree when the rust mycelium girdles the stem. The gall rust does not require an alternate host and is one of the most prolific of the rusts. The rust spreads by releasing spores that can travel hundreds of kilometres.
The VCF revisits all cut blocks and manages the new forests by pruning and felling infected trees and by planting alternate species where appropriate.
The Village of Valemount Community Wildfire Protection Plan (VCWPP) was commissioned in 2012. VCF initiated the process of updating this plan in March 2018 and continues to treat high risk areas around Valemount and along the corridor towards Tete Jaune. VCF is committed to help with fire preparedness for the community through planning and consultation.
Meetings were held with local agencies, the public and people who live adjacent to the most high-risk forests. The results of consultation were that some people were opposed to any harvest of the adjacent forest while others were frightened by the flammable forests in their backyards. Through this process, amendments were made to fuel management plans to accommodate concerns.
Some fuel management areas are not profitable to harvest as the trees are often non-commercial, dead and/or rotting. In spite of this, VCF continues to discuss and plan work with the Village and the Valemount Wildfire Base staff to minimize risk by creating fuel breaks that will be defensible in the event of wildfire.
Other fuel management areas around Tete Jaune Cache also require planning but are beyond the boundaries of the Valemount Community Forest.