When is clearcutting the right choice?
A clearcut is an area of forestland where most of the standing trees are logged in a single operation, and few trees remain after harvest. Forested buffers are left around streams and lakes, and the area is then replanted within two years of harvest. However, clearcutting is a controversial method of tree harvesting because of its visual effect on the landscape.
In western Oregon, clearcutting can be the most appropriate harvest method for certain tree species. For example, clearcutting is often used in Douglas-fir forests because new seedlings need direct sunlight to grow quickly. In eastern Oregon, most common tree species are much more shade tolerant, and therefore clearcutting is rarely used.
There are some similarities between a clearcut harvest and a forest opening caused by natural disturbances such as wildfires, windstorms, flooding and volcanic eruptions. Just like these natural occurrences, clearcuts create open space that many plants and animals need to flourish. Since a clearcut receives more sunlight, growing conditions for sun-loving shrubs, herbs and grasses thrive and provide forage for animals such as deer and elk.
- They look bad. Until the newly planted trees “green up” a hillside, a clearcut is not considered
appealing to the general public.
- Habitat disturbance. Clearcutting alters the habitat where trees once stood, and forest inhabitants
are displaced into new areas.
- Increased stream flow. Clearcuts allow more water to enter a stream system through underground aquifers
because water is not being taken up and released by trees in a process called “evapotranspiration.” Increased stream flows can lead to increased riparian erosion during high-water occurrences.
- Full sun conditions. Wide-open spaces allow the most sun for tree species that require full-sun conditions to thrive.
- Economy of harvest. Clearcutting represents the most efficient and economical method of harvesting a
large group of trees.
- Fewer disturbances to the forest floor. By entering a forest stand once, instead of multiple times over a series of harvest events, the landowner minimizes disturbance to forest soil.
Oregon regulates how clearcuts can be performed.
- Clearcuts may not exceed 120 acres in size and are limited when adjacent to scenic highways.
- Adjacent units may not be clearcut until seedlings are well established and “free-to-grow.”
- Forested buffers are required to be left along streams, lakes and wetlands.
- Landowners must also leave two standing live trees and two dead trees (standing or downed) per acre as wildlife habitat. Foresters often refer to this as “two up and two down.”