FOREST MANAGEMENT WORKSHOP MANUAL
It takes a lot of faith to look ahead sixty to eighty years
to grow sawtimber. But that is what growing trees is all about.
Every time a tree is planted, it's care is trusted to future
generations. This points out the need for the public to be
better informed regarding the necessity for managing our forest
lands and the techniques involved.
Fortunately, our forests have endured over the years because
trees are renewable. This basic fact means that we can continue
to enjoy the benefits from forests - and the growing forests
themselves - if we manage them properly.
The average forested tract in Kentucky consists of about 24
acres and is a community of small, intermediate and large-size
trees, trees of all ages, which under natural growing
conditions, grow too close together for maximum growth.
In some respects, this average tract is like a field of
tobacco - you can not grow good tobacco unless the plants are
properly spaced and some weeding is done. The same holds true
with trees. When working with trees, an individual should think
in terms of imporving the quality and growing conditions of the
crop trees if a good crop is expected. This is what management
attempts to do. With these considerations in mind, let's look
briefly at some management practices and what they are designed
Establishing a Timber Stand
- On abandoned fields or harvested sites, the landowner's
first consideration should be to establish a new stand of trees
for the next crop. This should be accomplished as economically
and quickly as possible with desirable species adapted to the
site. Several methods of reproducing a stand of trees are worth
- Natural Reproduction
- All trees produce seed. When a stand is harvested, a large
number of seeds will usually be available in the soil to
germinate if conditions are right. The proportions of different
species which make up a stand are dependent on the amount of
seed present, soil conditions, amount of sunlight, moisture, and
competition between plants. When properly done, this is the
most economical method of reproduction and usually results in
the most productive stands.
- Planting of tree seedlings is necessary when a seed source
of desirable species is unavailable, such as on abandoned fields
or when converting from one tree species to another. Trees need
to be properly spaced to minimize cultural practices and
expenses and selected on the basis of use and adaptation to
soils and climate of the area. (See Appendix, "Tree Planting").
- Direct seeding involves the sowing of seed on the ground
where it germinates and grows. Usually the practice is
accomplished with a plane, helicopter or hydroseeder. In
Kentucky, most direct seeding is done with a hydroseeder to
establish grasses and legumes on difficult sites as mine spoil
or road banks. Extensive direct seeding of tree species hasn't
proven to be a very successful practice.
- Coppice reproduction of a stand is by sprouts from either
stumps or roots of cut trees. The primary advantage of this
method is the rapid sprout growth from the already developed
root systems. Disadvantages include decay as the sprouts grow
and development of multiple stems. Coppice reproduction is
often a major component of any naturally occurring hardwood
- Site Preparation
- In reproducing a stand, best survival and growth is obtained
under optimum growing conditions. To achieve this degree of
success requires that undesirable competing growth be
controlled. Site preparation may consist of controlling brush
and herbaceous species by manual, chemical or mechanical means,
usually before and just after a stand is reproduced. Under
unfavorable conditions, site preparation can be a major cost of
Intermediate Cutting Practices
- A cutting made in a stand of trees in the age range of 1 to
20 years, to free the best trees from undesirable individuals of
the same age which are or may overtop them. The principal
purpose of this practice is to regulate species composition with
emphasis on the better species. Unwanted trees can be removed
chemically or by cutting. This practice is frequently
- Release Cutting
- A cutting made in a stand of trees between the ages of 1 to
20 years, to reduce competition of older overtopping trees.
Older trees may be good species but of poor form. The purpose
of this practice then is to release the new crop from the
unfavorable influence of older trees. Trees can be eliminated
by cutting, girdling, or chemical treatment. This practice is
- A cutting made in an immature stand of trees to reduce the
excessive number of trees per acre. This practice stimulates
tree growth while concentrating wood production on a limited
number of selected trees. The frequence of thinnings during the
life of a stand of trees depends on the tree species being grown
and site productivity. Yellow-poplar trees growing on a good
site may have a cutting cycle of 8-12 years. Upland oak species
growing on a good site might have a cutting cycle of 6-9 years.
There are several types of thinnings including selection
thinning, crown thinning, etc., which we will not discuss in
- Improvement Cutting
- A cutting in a stand of trees which are 20 years of age or
older. The purpose of the practice is to improve tree
composition and tree quality by removing trees of undesirable
species, form, or condition, from the main canopy. This
practices oftentimes includes grapevine removal. Trees may be
harvested if a market exists or merely cut or chemically treated
and left standing. One improvement cutting may be sufficient to
put the stand into condition or several cuttings over a period
of years may be required. Improvements cuttings should precede
a harvest cut by at least 10 years so the full benefit can be
obtained from the release of the better trees.
- Branches of trees are removed to increase the quality of the
wood. Trees usually pruned are pine species and black walnut.
Normally in pruning pine species, at least 30% of the total tree
height needs to be left in live crown to maintain maximum
growth. With walnut trees, at least 50% of the total height
should be left in live crown. Prune trees when they are young.
It is recommended that crop trees be selected and pruned when 5
or 6 inches in diameter. Remove limbs flush with the tree
trunk. Once the wound has healed over, new growth is clear and
of higher value.
Biological and Financial Maturity
The practices we have looked at so far are carried out
during the life of a stand. When a tree or stand of trees
reaches maturity, then harvesting practices must be considered.
But first let's look at maturity of a tree. Maturity varies
with tree species, site productivity, climate conditions, and
the product to be grown. Let's consider two types of maturity -
financial and biological. Financial maturity requires that the
landowner attaches a dollar value to growing trees. If the
expected value increase of a tree no longer equals or exceeds
the desired rate of return, then the tree should be removed and
replaced with a younger tree.
Biological maturity is the age a tree reaches before
beginning to deteriorate. Evidence of decline includes dead
tops, insect damage, rot, etc. The economic maturity of Yellow-
poplar on a good site may be 72 years, yet its biological
maturity may be 200-250 years. Most tree species in Kentucky
reach their economic maturity between 35-81 years. The higher
the interest rate desired, the shorter the rotation.
Now let's look briefly at harvesting practices.
- Selection Cutting
- Involves the harvesting of scattered mature trees in an all-
aged stand on a periodic basis. This practice affords a high
degree of protection to the site during and after logging and is
aesthetically pleasing. Disadvantages to the practice include
higher logging costs due to the scattered trees. Also it is
difficult to prevent injury to immature trees during logging
operations. The practice favors reproduction of shade tolerant
species such as maple, oak, and hickory rather than the
intolerant species. Reproduction comes from seed in the soil
and sprouts from stumps and roots.
- Clear Cutting
- Is a regeneration cutting and is used when a stand of trees
reaches maturity or when a stand consists of mostly poor quality
trees which need to be removed and replaced with quality trees.
After the merchantable trees are removed, all young growth 2" in
diameter or larger which remain must be cut or chemically
treated to allow for sunlight on the site.
Regeneration of the site may be by natural means or by
aritficial means. Natural regeneration results from seed in the
soil and sprouting from stumps and roots of cut trees (coppice).
Artificial regeneration would consist of planting the area with
seedlings raised in a nursery or direct seeding the area.
This practice has the advantages of reducing logging costs due
to concentrated logging on a small area, and is simple and easy
to apply. The new tree crop develops in full sunlight, favoring
intolerant species such as yellow-poplar, walnut, and ash. The
new stand is even-aged. Disadvantages of this practice include
temporary removal of forest cover resulting in increased runoff
and a change in the micro-climate of the area. However, soil
erosion is not increased beyond what would occur under other
cutting methods. Aesthetically, this practice is the least
desirable and it cannot be used effectively unless the wood
market will absorb all the material on the area.
- Involves the gradual removal of an entire stand in a series
of partial cuttings over a period of years of not less than 10
nor more than 20. Natural reproduction from seed and sprouts
starts under the protection of the older stand and is finally
released when able to endure exposure. Approximately 10-30% of
the tree volume is removed in each preparatory cutting. The
fundamental characteristics of the shelterwood method is the
establishment of a new crop of trees before completion of the
This practice is not normally used in Kentucky and results in an
even-aged stand or forest. The main disadvantages to the
practice is the damage to the young trees during the removal of
- Seed Tree
- The area is cut clear except for scattered trees called seed
trees left standing singly or in groups for the purpose of
furnishing seed to restock the area. Less than 10% of the
original volume is left standing in seed trees. After the new
crop is established, seed trees may be removed in a second
cutting or left indefinitely.
The number of seed trees left on an area range from 1 to 10 per
acre depending on the tree species, tree size, type of seed,
This practice creates an even-aged stand or forest. It
concentrates logging on a relatively small area, tending to keep
costs down. It is simple and easy to use.
The disadvantages of the practice include complete exposure of
the site following logging. The practice isn't aesthetically
pleasing and is restricted to windfirm species having wind
dispersed seed such as pine.
- Salvage Cutting
- A cutting made for the purpose of removing trees killed or
damaged by insects, disease, wind, etc. It may involve complete
or partial removal of a stand.
All trees have their enemies. In many private holdings,
fire and domestic animals lower the productivity of the woodland
more than insects and disease.
Fire causes damage to trees, some of which is not easily
recognized. Fire may kill young trees in a forest and damage
older trees, leaving fire scars where rot may enter. Fire
weakened trees may be attacked by insects and diseases or more
easily felled by wind. The composition of a forest may be
changed by fire, in time becoming a scrubby growth of inferior
species. A woodland owner may suffer losses in his cash-crop
trees even though the fire actually kills very few of them.
- Insects and Disease
- Insects and diseases may kill trees, retard growth, or mar
wood and tree form. The annual toll of timber killed or ruined
by diseases alone in the U.S. is 40 percent as much as timber
cut. Farm woodlots are especially susceptible to diseases,
especially if grazed or burned frequently. Much of this problem
may be eliminated by removing infected trees or those likely to
become defective in early life, such as scarlet oak.
- Most landowners are not aware of the problems created by
allowing livestock to graze hardwood forests. Hardwood forests
will tolerate only light grazing. Higher concentration of
cattle will damage surface feeder roots and compact the soil,
reducing its absorptive capacity. In general, the farmer who
uses the farm woodlot as a pasture is creating a loss for
himself and the livestock. Forage grown in a forest is poorer
in quantity and quality than open pasture. Research has shown
that an improved grass-legume pasture can produce 11 times the
yield by dry matter as compared to forage in a forest or
- The home of tree roots is the soil, and the growth of the
tree and the productivity of the forest are directly affected by
the quantity, quality and location of the soil. Man's
activities in the forest do cause an increase in soil
disturbance. A harvesting operation, access roads, grazing or
even a hiking trail may be a source of soil erosion if poor
judgement or a bad practice is applied. Soil loss from erosion
in turn affects soil productivity and tree growth. Through good
planning and application of preventative practices, erosion can
Because of what man has learned about growing trees, there
should be no problem in supplying our present and future needs
from the forests we have - except that man hasn't yet put all of
what he knows into practice.
Jump back to Table of Contents.
Last revised August 14, 1995.
Please send comments to: Duane Bristow (firstname.lastname@example.org)