Friends of the Black Butte Trail




How does the removal of 250 smaller trees for the Black Butte Trail fit within the context of managing our forests for fire and water conservation?

"When Lewis and Clark explored the Northwest, the forests were relatively open, with 20 to 25 mature trees per acre. Periodically, lightning would start fires that would clear out underbrush and small trees, renewing the forests. Today's forests are completely different, with as many as 400 trees crowded onto each acre, along with thick undergrowth. This density of growth makes forests susceptible to disease, drought and severe wildfires. Instead of restoring forests, these wildfires destroy them, and it can take decades to recover. This radical change in our forests is the result of nearly a century of well-intentioned but misguided management." (Gale Norton, U.S. Interior Secretary)

Before serious fire suppression started a century ago the ponderosa forests in the Sisters area could count on burning every 11 to 15 years. Fires were started by lightning and the areas burned were generally small in lateral extent, hugging the ground with flames not exceeding four feet.

Forest fires today are generally much larger, more intense and difficult to control than in the past because fire cycles have been missed. Many will remember when Black Butte Ranch was evacuated in 2007 by the GW Fire, and when the Crossroads and Tollgate developments had to be evacuated because of the Lake George Fire in 2006. Some fires today have become catastrophic, such as seen in many parts of the 2003 B&B Complex Fire and the 2014 Two Bulls Fire.

The 2009 Greater Sisters Country Community Wildfire Protection Plan lists the risk of forest fires in the Sisters area, based upon historical fire occurrences, ignition sources, weather, topography, fuel and community preparedness. The Oregon Forestland-Urban Interface Fire Protection Act (also known as Senate Bill 360), has applied fire risk classification for wildland/urban interface areas. The fire risk classification assessed to Black Butte Ranch is “Extreme”. For the communities of Sisters and Crossroads it is assessed as “High”.

To help control the threat of catastrophic wild fires, fuel breaks are being created, overgrown forests are being treated by pruning, mowing and eliminating smaller trees that can carry fires into the crown of trees, especially near areas of human developments. Once treated, prescribed ground fire burns can be initiated to help reestablish a healthy ecosystem. The goal is to reduce severe fire risk by creating stands with widely spaced trees, low surface fuels, higher crowns and large fire resistant trees.



Thinning of trees to reduce catastrophic wild fires. From U.S. Forest Service kiosk near Suttle Lake, Oregon


US Forest Service employee shows the core of a 60 year old ponderosa pine tree from the Sisters area forests. The tree was located in in a dense overgrowth of trees, packed too tightly next to other trees to obtain adequate light, nutrition or water. A compromised tree such as this is susceptible to disease and insect infestation, and in the case of a forest fire, will provide ladder fuel, allowing ground fires to reach upward into catastrophic crown fires.

When overgrown forests are thinned, fewer trees use moisture from precipitation. In a ponderosa pine forests in Arizona, a similar environment to our forests in the Sisters area, cumulative increases in runoff measured after thinning over a 15 year treatment period ranged between 20% and 26%.

Friends of the Black Butte Trail feel that the loss of trees for the construction of the paved trail are acceptable.The trees are generally small in size and similar to trees the US Forest Service removes when thinning forests. After removing trees along the trail alignment additional sunlight and moisture that will be made available to trees bordering the paved trail, resulting in more vigorous growth.

You Tube Video: Managing Forests and Forest Fires in the Sisters Area - U.S. Forest Service



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