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RMOW begins largest tree thinning project Sept. 13

Work on Blackcomb Benchlands will cover more than 15 hectares



Tree thinning will begin in the Blackcomb Benchlands area Sept. 13.

Thinning will be conducted by a contractor on behalf of the Resort Municipality of Whistler, as part of Whistler's wildfire management strategy, and will continue until snowfall this year and then recommence in the spring.

The prevalence of forest fires in British Columbia this past summer highlights the need to manage fire risks in forests surrounding communities such as Whistler, according to a RMOW press release. Tree thinning is a key strategy recommended in Whistler's Community Wildfire Protection Plan and is intended to reduce the volume of woody fuels in or close to populated areas, so Whistler's fire protection efforts can be more effective. The forests targeted are primarily the dense, second-growth forests, which occur throughout much of the valley bottom.

Funding for tree thinning is provided by the Union of B.C. Municipalities and the Province of B.C. as part of their efforts to protect life and property throughout the province.

The reasons for tree thinning are:

• To limit the ability of the forests to sustain a crown fire (A crown fire is a fire that moves unimpeded and with great speed along the tops of the trees. Thinning opens the forest canopy by removing smaller trees, so the forest is less likely to support a crown fire.)

• To help maintain access for fire protection crews

• To reduce surface and ladder fuels (i.e. branches and small trees that could otherwise allow a fire to move along the forest floor or act as a ladder up to the forest canopy).

Some large pieces of wood (over 30 centimetres) are left on-site to help provide habitat for a variety of animals. Thinning this way helps accelerate the forest back to old-growth conditions and increases light to the forest floor. By thinning forests, fire risks are reduced and wildlife habitat and biodiversity opportunities are increased.

The Benchlands thinning project includes the dense forest above developed areas in the Blackcomb Benchlands. This area includes a water reservoir, access roads to Blackcomb Mountain, and the Roam in the Loam bike and horse trail, and is bound on the south by the ski run adjacent to the Coast Blackcomb Suites and on the north by Horstman Creek. Thinning will occur between the property boundaries on the downhill side, and extend uphill approximately 200 metres. Much of the area was clearcut in the 1970s and other parts were cut in the late 1930s. Small remnants of old-growth forest and individual old growth trees are interspersed on the site.

The area will be thinned from below: that is, smaller trees will be cut while larger trees will be retained. One way to picture this approach is that the diameter of the resulting stumps will be smaller than the diameter of the remaining trees. Average spacing between trees will be four to six metres. Virtually no branches or other fire fuels will be left on the forest floor. Openings in the canopy will allow light to reach the forest floor, which will encourage the growth of understorey vegetation. Over the next few years, the moss, herb, and shrub layer will respond to this additional light.

Tree thinning operations will be limited to daytime hours, Monday through Friday. Trails and roads may be temporarily closed during these hours and detours will be provided.

Tree thinning in Whistler began with a small trial in Lost Lake Park in 2004. It expanded in subsequent years to include the main trail network through the park. In 2009, thinning occurred for the first time right at the interface between developed and forested areas in Kadenwood. Thinning of approximately five hectares on either side of Kadenwood Road was completed in May 2010. The Kadenwood thinning project removed approximately 140 large bins (750 tonnes) of wood from the site. The wood was trucked to the Whistler composting facility and contributed almost six weeks of wood supply for the composting process.

The Blackcomb Benchlands thinning project is the RMOW's largest thinning project to date and includes over 15 hectares of forest. Approximately the same volume of wood as in Kadenwood (150 tonnes per hectare) is expected to be removed from the site and trucked to Whistler's municipal composting facility. Approximately 10 loads (one load per hectare) of small logs destined for pulpwood will also likely result. Any net revenue from these logs will be reinvested for future tree thinning projects.