Creating Defensible Space to Protect Structures from Fire

Aerial photo shows home where surrounding tree cover and vegetation has been cleared and/or thinned of combustible fuels. This provides “defensible space” where fire personnel can defend the house from the onslaught of wildfire.

Photo on right side shows before ladder fuel thinning. On the left after thinning where “ladder fuels,” such as the pictured manzanita is mechanically reduced to slash and left on the forest floor. The resulting viewscape is called a “shaded fuel break.”

Slash remains on forest floor after ladder fuels have been mechanically harvested. This thinning reduces the ladder fuels that allow fire to climb surrounding trees and produce a deadly tree-top fire spread. The result of such thinning produces a see-through viewscape that greatly reduces a fire from spreading.

A forest worker surveys an area that is ready for mechanical harvesting. The brush, manzanita, is a high combustible low growing shrub that accelerates the spread of wildfire.

Forest floor after mechanical harvesting of low growing ladder fuels. This slash do not support rapid fire spread.

After thinning out low growing ladder fuels, the result is called a “shaded fuel break.” This opens up the view and reduces the threat of a wildfire from rapidly spreading.

Proper brush thinning helps protect this home from being lost to wildfire. The result of the brush clearing/thinning is a open view pictured here called a “shaded fuel break.”

The Way Mother Nature Protects the Forest

This mature forest shows the open “viewscape” where ladder fuels that promote the rapid spread of wildfire through the tops of trees is greatly reduced. This particular forest has been thinned naturally by lightning produced fires that occurred about every five to ten years. These fires control the underbrush and result in keeping the forest healthy. The burn marks seen on the bark of these ponderosa pines does not harm the trees.