November 2002 - Logging and Sawmilling Journal -

A new tree girdling tool—appropriately called the Barkblaster—is getting positive feedback from the industry.

The mother-son team of Margret and Erol Toyata developed the Barkblaster, which reduces the fast growth of deciduous trees by girdling them in a consistent one-inch wide path.

The small hand-guided tool snugly follows the aspen’s contours. With a quick, easy movement, it efficiently removes a uniform strip of bark. It’s the same story with a larger diameter tree—the bark is unzipped in a flash. This new generation of girdling tool is called, appropriately, the Barkblaster. It’s the end result of nine years of practical silvicultural work by the mother and son team of Margret and Erol Toyata, partners in Twin Rivers Forestry Inc, based in Prince George, British Columbia. And it appears to have paid dividends.

The Barkblaster has received positive reviews from regional forest and silvicultural companies. The re-designed Barkblaster is faster than anything out there right now, meaning it delivers high productivity and a consistent girdle width to curtail the tree’s growth, says Erol.

Girdling is a tool from the silvicultural arsenal used to help young coniferous crop trees compete for light, oxygen and nutrients with faster growing deciduous species deemed unwanted on a growing site. The spraying of target chemicals to achieve the same objective is probably the cheapest method but comes with drawbacks, says Erol.

He notes that removing deciduous species in young plantations with saws produces a high slash load, can damage the leaders on residuals and the resulting excessive exposure to sunlight can scald tree seedlings, especially spruce. Erol says the improved productivity possible with the Barkblaster will help reduce per hectare costs to manageable levels and improve the girdling option. A problem in the past has been the girdling band width has been too narrow, he says. The potential problems there are twofold.

A second and time-consuming band sometimes had to be cut to meet the width specifications called for in the girdling contract. A narrow, uneven band width can leave cambium bridges within the band, keeping the tree alive. Erol says the Barkblaster always cuts a one-inch-wide path, sharply reducing the bridging possibility. The tool severs the cambium layer and thus the nutrient flows without cutting into the sapwood.

The girdling ring is placed below the lowest live limb, otherwise the tree will continue to sprout, he adds. The principal productivity gains with the Barkblaster accrue because the girdling tool requires no adjustment between tackling trees from 3/4 inch in diameter to 10 inches in diameter, says Erol. The Barkblaster has evolved through experience into a user-friendly device, says Margret. It’s surprisingly compact. At about eight inches tall, with a duck shaped head that helps it ride alongside the outer diameter of the tree, it weighs under a pound—a consideration during a 10-hour day in the bush.

The Barkblaster is made of injected moulded durable plastic by Pacific Engineered Plastics of Edmonton. With its patent pending, the device is being handled by Canadian Forestry Equipment. As a reforestation services company, Twin Rivers has built good working relationships with local forest companies. The Barkblaster prototype was used on a 300-hectare brushing and spacing project for The Pas Lumber Co in 2000.

The project was co-ordinated by Integrated Silviculture Systems, and spokesman Dan Upward confirmed the girdling tool’s worth. “I believed it worked out very well and was successful in girdling the targeted species. It’s a little bit more versatile (than other girdling tools) and is definitely an interesting development.” Since then, the girdler has been re-designed and extensively field tested on Dunkley Lumber forest lands.

The Toyatas are appreciative of the help proffered by Dunkley during the development. “They’ve been very good to help us out,” says Erol. “It takes thousands of dollars to develop the Barkblaster and companies like Dunkley make it possible for small companies like us to be innovative.” It works both ways. “The main advantage is it’s very suitable for tackling a large range of diameter sizes and the other nice thing is the depth of girdle is exactly what we want,” reports Doug Perdue, operations forester for Dunkley. “It doesn’t penetrate the sapwood and reduces suckering.”

Dunkley has used girdling techniques for more than 10 years. “We tend to use girdling on small patches, on clones or clumps in cut blocks. The tool helps us with our ability to reach free-to-grow stage.” Perdue adds that the Barkblaster gives Dunkley the treatment it requires and is more effective for crews in the bush. “It’s the next generation.”

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