To keep forests healthy and people safe, forests need to be thinned. The reasons are multiple, and the importance is great.
Forest thinning is the process of removing dead branches and dead trees, removing smaller trees to all those remaining to have a better chance at survival and clearing burnable debris from the forest floors. In areas containing houses, this includes removing branches that overhang the houses, and the brush that is very close to the houses.
There are two distinct camps of thought regarding forest thinning. Some groups, including many environmental groups, especially fundamentalist groups, feel that since it isn’t “natural”, it shouldn’t be done under any circumstances.
The other side, which includes the United States Forest Service and many forest management groups, say that forest thinning is essential to keeping the forests healthy while also keeping people safe.
Many people feel that there is a need to thin, and in areas where this hasn’t been done, it isn’t uncommon for the forest to become weak. This is quite similar to what happens when a gardener allows weeds to grow throughout the garden.
In a forest that hasn’t been thinned, dead trees, both standing and on the ground, grow in number. Branches, limbs, leaves, needles, and other sources of fuel for fires cover the ground. Brush overgrows the area, and many of these are also highly burnable and litter the forest floor. The result is that especially if an area becomes dry, as is experienced in many forests, this is a tinderbox, just waiting for a major fire to happen. When there is a great deal of fuel and it is dry, any spark or heat can set it off. This includes lightning strikes, carelessly disposed of and smoldering cigarettes or heat from an exhaust pipe.
In areas where brush grows to close to a home, or where tree branches overhang the home, even a small fire can result in the destruction of the home. Such fires are also exceptionally difficult to contain and put out, since it will burn as long as there is fuel to burn. Yearly experience tells indicates that this is a recipe for disaster. It is not at all uncommon for over 500,000 acres of forest to burn each year, and this is primarily in forests that haven’t been thinned.
Further, if standing trees are dead due to infection or insect infestation, leaving them there merely allows the infection and infestation to spread, which kills more trees, ultimately adding to the fire danger, as well as to the death of otherwise healthy trees. The problem can be made even worse if the trees are growing so close together that the trees are already weakened.
Fires also do more than putting people’s lives at risk. The intense heat from the forest fire can also cause considerable damage to living and growing trees. This can be devastating, particularly for younger trees.
The reverse is true, as well. In the 1990s, a fire swept through an area of Northern California. There were several nice home in the area. However, not all of the forest had been thinned. The destruction in the forest that hadn’t been thinned was extreme, and nearly every house there burned to the ground. In the thinned area, no houses were lost, and damage was minimal.
To keep forests healthy and strong, they need to be thinned. This not only helps the well-being of the forest and all of the creatures living in it. It also helps keep people safe from the dangers of a wildfire.
Winema-Fremont National Forest, Oregon
Modoc National Forest, California
Steve Trulove, Thermal Imaging Specialist, US Forest Service, ret.
Oregon State Forestry Department