Five Reasons to Thin Your Forestland

Thinned Forest Whether you own 5 acres, 50 acres, or more than 500 acres of forestland, you have an obligation to be a good steward to the land... and one of the most important ways to be a good steward is thinning your forest stand, removing unhealthy, unmarketable, defective, and overcrowded trees growing too closely together -- thus allowing your remaining healthy trees greater access to the nutrients they need to grow stronger and healthier.

Thinning your forest does take planning, effort, and time, but the reasons outlined in this article will demonstrate the benefits you'll receive from thinning. The type of thinning we refer to in this article is called pre-commercial thinning.

State and national resources -- foresters and cost-share programs -- can often assist you in the process. Many of these programs partially pay the landowner to do the thinning -- either by managing the process him/herself or by hiring out the process to an approved contractor.

Why should you thin your forest?

5 Reasons to Thin Your Forestland

Forest Health: A Thinned Forest is a Healthy Forest

Overgrown forests may look pretty -- and even offer you privacy from your neighbors -- but tree overcrowding leads to unhealthy, stressed, and weak trees. Unhealthy trees tend to be defective; some grow weak and collapse against surrounding trees while others become much more susceptible to diseases and deadly bug infestations.

Too many trees competing for limited resources (soil nutrients, sun, water) lead to trees susceptible to every possible failure... and untreated, a healthy forest can quickly turn unhealthy. Thinning reallocates these key, limited resources to your remaining, best trees. (See a graphic depiction of this issue here.)

Thinning a forest leaves the remaining trees in greater health -- enhancing their vigor to deal with periods of drought and fight off invasive insect attacks.

Finally, having too many trees contributes to an overabundance of fuel for wildfires.

Defensible Space: A Thinned Forest Reduces Wildfire Effects

If your summers are dry like ours, you always have to worry about wildfires. Overcrowded forests typically not only have more debris on the forest floor, but when trees are so close that they are touching each other, fire can more easily spread. Keeping your forest thinned and pruned forces fire to stay on the ground, greatly slowing its progress.

Those of us who live on forestland love the idea of having our forest up close -- the idea of living among the trees. You can still have this ideal with thinning your trees, though you may want to think twice about how you treat the 100 or so feet that surrounds your house and outbuildings.

Thinning more heavily around your house -- creating what experts call defensible space -- does not guarantee that your house will not burn down if a wildfire burns through your land, but creating this defensible space greatly enhances the chances that the fire will not have the fuel needed to do so. (See a graphic depiction of this issue here.)

You can contact your local forester or fire department to learn more about this concept. If you are part of a community, you and your neighbors could consider taking additional steps to become a Firewise Community.

Timber Value: A Thinned Forest Aids Development of More Marketable Trees

If you plan on logging your forestland, thinning your overcrowded trees just makes economic sense. Removing defective and weaker trees allows the remaining healthy trees access to the key ingredients to foster their growth, including diameter growth. This diameter growth leads to an increase in tree volume... resulting in higher total payouts for your timber from the lumber mills.

How much more volume you get depends on when (and how often) you thin your trees, as well as the type of tree. One study of Douglas Firs saw an average increase in diameter growth of 16 percent when thinned; a study of loblolly-shortleaf pines found an average diameter increase of 25 percent in lightly thinned stands and 36 percent in heavily thinned stands. (See a graphic depiction of this issue here.)

In addition to thinning weaker trees, if you own a diverse forest, you can thin based on species value, eliminating trees of lesser value.

Undergrowth Diversity: A Thinned Forest Increases Diversity of Underbrush

When you thin your forest stand, two things happen. First, by the simple act of thinning, you disturb the soil, often causing new plants to grow. Second, the increased light from thinning often stimulates the growth of more grasses, wildflowers, and native shrubs. (See a graphic depiction of this issue here.)

Wildlife: A Thinned Forest Provides a Better Habitat for Forest Animals

Providing open spaces among your trees actually increases the likelihood of visits from additional wildlife.

Further, the increase in the number of native plants growing in the undergrowth as a result of thinning creates additional sources of food and shelter for wildlife.

Final Thoughts on Thinning

It's amazing how many neighbors will notice how much better your forest looks after it has been thinned, often inspiring others in your community to develop an interest in better managing their forestland... and the more people who manage and thin their forestland, the healthier -- and safer -- the entire community.

So... thin for yourself -- and inspire your neighbors to follow suit! We need all the healthy forests possible.

If you're not sure about how or when to thin, consult the resources below and then contact your local state forester for assistance in developing plan for your forest.

To Learn More About Thinning -- How, When, Why -- Use Some of These External Resources:

  • A Beginners Guide to Forest Thinning on Private Lands
  • Are My Pine Trees Ready to Thin?
  • Thinning Forest Stands
  • Guidelines for Thinning Ponderosa Pine for Improved Forest Health and Fire Prevention


    Questions about some of the terminology used in this article? Get more information on key silviculture and forestry terms by going to our A Forestry, Forest Practices, Silviculture Glossary for Beginning Foresters.


    Hansen Woodland Farm Founder Dr. Randall Hansen Authored by Hansen Woodland Farm owner, Dr. Randall Hansen. Besides a passion for forestry, Dr. Hansen is also founder of Quintessential Careers, the Web's most comprehensive career site, as well as CEO of, a network of sites with expert advice, tools, and resources to empower people to improve their lives. Visit his personal Website or check out Dr. Hansen on GooglePlus.

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