Managing your forest land – Landowners Top-10 Frequently Asked Questions
US Forest Service, State and Private Forestry – Northeastern Area
Forest Stewardship Program

4.  What is stand improvement?  Can it make my best trees even better?

What can stand improvement do for my forest?
You may look at your property and wonder if you can take some action to help make the best of your forest.  You may want more timber in the future, greater mast crops for wildlife, healthier trees, more robust fall color, or all of these.  All “ forest products ” can be enhanced through stand improvement.  Traditionally, stand improvement was known as TSI or Timber Stand Improvement.  TSI focused on concentrating growth on those trees for timber crops.  Because most owners desire more than timber, TSI is now often referred to as forest stand improvement or just stand improvement.

What is stand improvement?
Simply put, stand improvement is a treatment, or action, that improves the growth of your best trees and removes any trees that are in their way.  Stand improvement can be completely adapted to the specific site conditions, ownership objectives, and resources at hand.  Stand improvement generally does not attempt to establish new seedlings, but rather to enhance the best existing trees.  Stand improvement is hard work because it usually involves cutting trees, but it might also involve herbicide applications, prescribed burning , or girdling .  To provide the values that humans want and need, trees need to increase in size each year.  Often, the faster and bigger they grow each year, the more abundant the products, such as wood, fruit, and sap.  Trees are unlike animals that stabilize in size at maturity. 

How does stand improvement work?
In our region, the factor that most limits tree growth is access to sunlight.  (In some cases, competition for soil water and nutrients may also limit growth.)  The simplest thing you can do to improve your forest is to make sure that your best trees have access to plenty of sunlight.  Stand improvement improves the growth of desired trees by reducing their competition with other trees for sunlight.  The trees that have the greatest potential to provide the values desired by the owner are the ones that should be retained and enhanced by stand improvement.  The trees that have less potential and that compete with the desired trees should be cut. 

Which trees should be cut?
The first time a forest is treated to improve growth, the trees cut should include undesired species, trees of poor form or health, trees of low vigor, or trees at risk for damage due to unstable branching patterns.  The intensity of the stand improvement treatment--the number of trees cut per acre--will depend on several factors, including tree species, soil productivity, ownership objectives , labor and equipment availability, and more.  To make sure you get the details right, contact your service forester.   Alternatively, you can work with a private sector forester to determine if the treatment can be done as part of a commercial operation .  Be certain that the forester (FAQ 1) understands your desire to emphasize cutting of the lower grade trees and thus ensure an improvement in the stand.  Once undesirable trees are removed from the forest, subsequent improvement treatments will require greater attention to the ownership objectives as the most desirable trees will have to be retained from among other semi-desirable trees.

Can I sell the trees that are cut?
Depending on the size and quality of trees being cut, the volume available, and local markets, you may be able to sell some or all of the cull trees.  Selling trees from an improvement cut has the advantage of generating some amount of revenue while having the work performed by someone else.  The revenue may be quite small; in fact, there may well be no net gain, but revenue may cover the cost of the treatment.  In many cases the ability to get the work completed is more than sufficient compensation. 

Is there anything I need to be careful about?
Although stand improvements can be an excellent idea in the right situation, there are a couple of things to be careful to avoid.  First, it’s critical that the forester and/or logger involved clearly understand your objectives for the treatment.  If your desired outcome depends on leaving the best trees in the woods, then it’s critical that your forester and logger understand that.  The opposite approach, removing the best trees and leaving behind the worst, can seriously degrade the quality of your stand for years to come.  This is called high-grading and is the opposite of stand improvement.  Second, a careless contractor may do excessive damage to the residual stand .  This could seriously undermine the future condition of the stand.  A forest management plan developed with a skilled professional will help avoid these problems.  All cutting should be supervised to ensure quality standards are met.

Do I have to remove all of the trees that are cut?
In situations where there are few cull trees, trees of small size or poor quality, or no local markets for low-grade trees, the improvement cut will be noncommercial .  In these cases, it’s common for the forest owner to personally cut the trees, or to pay someone to cut the trees.  Don’t feel that you need to remove all of the cut trees; in our region there are seldom ecological problems associated with just leaving them on the ground.  The cut stems form slash that benefits many wildlife species.  Also, as these stems decompose, they release stored nutrients back into the forest soil.  Your service forester can advise you of any risks specific to your area and situation.  Any utilization of the cut trees should be closely monitored to ensure the correct equipment is used and that harvest is done safely with minimal damage to the residual stand.

Where can I find more information?


Recommended Web link

Stand improvement

Selecting and marking trees

Avoiding stand degradation



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