A crucial forestry tool

Thinning is often the most important thing you can do to influence the growth and health of your forest. Proper spacing and thinning can reduce overcrowding and relieve tree stress. This helps maintain the health and vigor of your forest. Thinning can reduce fire hazards, generate revenue, and increase the value of remaining trees. From an aesthetic perspective, thinning helps create a more open forest stand, which can also improve habitat conditions for widlife species.

Learn the proper time and method for thinning your forest

The following resources will help you decide if thinning is right for you and your forest. Start with the presentation below titled Thinning Basics with Glenn Ahrens (under 'Presentations'). It gives you an overview and some guidelines for thinning based on how trees compete for sunlight, moisture and nutrients. If you decide that thinning makes sense for you, continue to explore these online resources to learn how to thin, or where to get more help to plan and implement a thinning operation. 

For more information, please conact:
Glenn Ahrens, Oregon State University Extension Agent



OSU Extension Service Publications
Oregon State University Extension has several practical publications on thinning. You can get these publications in hard copy from your local OSU Extension office, or online at Extension and Experiment Station Communications. Below is a selection of available publications.

- Competition and Density in Woodland Stands. Get the most out of your woodland with a thorough look at competition among trees and the density of your woodland stand. Learn to use guidelines specific to your tree species to determine the best time to thin your trees to achieve your desired results.

-Thinning: An Important Timber Management Tool. This publication discusses how thinning affects individual tree growth and stand growth, including growth responses, thinning shock, tolerance levels of common Pacific Northwest tree species, crown classification systems, and stand yields.

-Reducing Hazardous Fuels on Woodland Property: Thinning. This publication describes benefits of thinning a stand of forest trees. Benefits include increased potential economic value as well as better protection against wildfire. Outlines thinning rules and regulations and how thinning is done.

-Ecology and Management of Eastern Oregon Forests: A Comprehensive Manual for Forest Managers. An overview of Eastern Oregon forest types and various silvicultural systems for managing them. Discusses in depth the ecology and management of ponderosa pine, lodgepole pine, and mixed-conifer forests.

Extension CMS Topics: 


  • Timber salvage after wildfires Wildfires burn thousands of acres each year on lands protected by the Oregon Department of Forestry and the Forest Protective Associations, spurring many landowners to begin timber salvage operations. The following information should answer many of the questions you, as a landowner, may have about salvaging timber from burned areas.