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Cutting Fuelwood and
Improving Your Woodland
As home heating costs rise, many woodland owners are turning to wood
as a low-cost energy alternative. This renewed use of wood for fuel is an excellent opportunity to remove undesirable
trees (crooked, decayed, or otherwise low quality) and give the more desirable, straight, healthy "crop trees"
room to grow into quality sawlogs and veneer.
How can cutting trees improve the forest?
Trees, like farm and garden crops, need room to grow at their maximum rate. When they are too close together, trees
will compete for water, sunlight, and nutrients, causing them to grow more slowly. An acre of woodland can only
grow a certain maximum cubic foot volume per year. The continuous removal of poor-formed and low value timber trees
will allow the well-formed, high quality timber trees to grow more rapidly in diameter throughout their lives.
Which trees should be removed?
For many woodland owners, cleaning up dead wood is an obvious source of fuelwood, but look closely before cutting.
Standing large, dead trees provide necessary homes for cavity nesting birds and wildlife. It is best to leave two
or three of these wildlife “homes” per acre. Dead, broken or blown down trees can be utilized for firewood or left
for small creatures such as salamanders. Hemlock seeds need rotting trees on the forest floor as a “nurse” tree
to begin their life.
When thinning a woodlot, remove those trees which have little or no potential to become 16-foot sawlogs. Crooked,
partly rotted, or badly damaged trees make good choices for home fuelwood, also forked trees or those sprouted
from old stumps. Clumps with many stems should be eliminated. Basswood can be thinned to the best two or three
stems. For forked trees where the fork is at or near ground level and the smallest fork is 3 inches or less in
diameter, you can cut the small fork or limb.
Valuable trees should be preserved for future log production. In Northern Michigan sugar maple, northern red oak,
white oak, black walnut, basswood, white ash, black cherry and red pine are some favored species. When other species
such as beech, ironwood, aspen or pin oak are crowding valuable trees, they should be removed. Some trees are valuable
for specific uses and should remain in the woodland for this reason. For example, black locust makes excellent
fence posts. Your forester can assist you with identifying the valuable trees for your locality and use.
There is a limit to the amount of thinning a woodlot should undergo at one time and care should be taken not to
cut too heavily. Cut only about 1/5 of the live trees at one time because heavy cutting can result in serious brush
invasion, excessive sprout growth, and side branching. One of the best ways to plan a cut is to base it on selecting
and releasing crop trees.
How are crop trees selected?
The best trees of the most valued species should be selected with thought given to proper spacing. Potential crop
trees should have a large crown and straight bole or trunk with few or no branches on the lower 16 feet. Ideally,
a crop tree should be selected every 20 feet (about 100 per acre), but nature does not space trees evenly. A compromise
is generally in order. If two high quality trees are side by side, the best decision may be to accept both as crop
trees and release each on two sides. In most cases, crop trees selected will be 15’ to 25’ apart. The field procedure
for selecting crop trees is this: start 10 to 20 feet into the stand from the property line. Select a crop tree
and identify it, either by tying a ribbon around it at breast height, or using a spot of paint. Then, pace about
20 feet (eight steps) on a line parallel to the edge of the stand or property line. Mark the closest crop tree
within a 5 to 7 foot radius. If there are no trees that meet the crop tree specifications within this circle, pick
the best of the lot and mark it. If there are no trees, pace out another 5 feet (two steps) and try again. If there
are not any trees within 7 feet of the second spot skip it and start over again at the next spot 20 feet away.
Follow this procedure until you reach the far edge of your stand or the distance you have previously decided to
go into the stand. When you reach the end of the first line, pace off 20 feet at a right angle to the first line.
Pick a tree, mark it, then go back along a line parallel to the first line. Use the paint spots or ribbons on the
crop trees of the first line to guide you as you proceed on the second line.
How much growth space do crop trees need?
One indicator is up in the crown. The crown of a crop tree needs three to five feet of open space on at least two
sides. Those tree crowns touching the crop tree crown are competitors and should be cut. Also, the amount of growth
space needed for each tree varies with the diameter of the trunk. Tree diameters are measured at 4 1/2’ from the
ground (diameter breast height or dbh) and the larger the diameter, the greater the spacing distance can be. For
hardwoods in Michigan a spacing distance (in feet) of 1.67 x dbh is recommended. For example: Distance between
trees (in feet) = DBH x 1.67.
What about harvesting sawlogs?
If the trees in your forest average 14” in diameter or larger, you should consult with your local forester before
cutting. In many cases, a thinning of these trees can be sold as sawlogs and the tops then utilized as fuelwood.
How much wood can a woodlot provide?
The growth in Michigan woodlands varies greatly with tree species composition and soil type. Once a woodland has
been thinned, it will be ready again for another thinning in about 8-10 years. For continuous fuelwood production,
divide the woodland into 10 equal blocks and work in one each year. If this does not yield enough wood, you will
have to look for an additional supply to avoid over-cutting in future years. On the other hand, any excess in that
block can be cut and sold without depleting future supplies.
NOTE: This document is designed to describe one system of thinning a woodlot. Refer to other documentation
on why a woodlot should be thinned and how to choose trees for cutting, or call our forester at (231) 882-4391
for more information.
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