It is tempting to say that a battle rages in your forest. Authors often use this analogy to explain the competitive forces that are at work in the woods. While this may read well, it erroneously lends human terms and emotions to a process that is strictly a matter of physics and chemistry. In the science and art of growing trees, the smart owner recognizes this and tries to understand what is going on. Then, like a gardener on a large scale, he can manipulate the factors involved to produce what meets his objectives.
In forestry jargon, producing and tending the forest is called silviculture (tree-culture). This is the heart of forest management, a term with broader inclusions such as finance, personnel management and fire protection. In its most useful sense, silviculture requires a knowledge of what each species needs in order to reproduce and grow. This foundation of silviculture is termed silvics - the characteristics, life histories and ecology of trees.

Silvicultural Systems
A silvicultural system is simply the method selected to grow and reproduce the forest in a way that combines the biological needs of the species and the personal objectives of the owner. Unfortunately, one sometimes excludes the other. In fact, on public lands such as national forests, major conflicts often arise when foresters select a silvicultural system that is inconsistent with the public's idea of what the land should provide.There are many variations on the systems outlined in the following pages. Sometimes trying to consider all the natural and economical factors involved can be frustrating. Here is where the experience of a forester comes in handy, so it is a good idea to ask for a professional judgement before making you final decision.

Silvicultural systems range from the relative simplicity of clear-cutting and planting to the more complicated methods of selecting individual trees to cut in an attempt to maintain diversity and a steady supply of maturing timber. Silviculture usually relies on two kinds of cutting during the life of a stand. These are: intermediate cuttings to improve or maintain the desired composition and structure of the stand and vigor of the trees intended as the final crop; and reproduction or harvest cuttings that end the growing period for one stand of trees and provide for the establishment of the next crop.

The array of silvicultural options can be diagrammed like this:

Intermediate Cuttings
In most managed forests, there are advantages in making certain types of cuttings long before the trees mature or are ready for a final harvest. During this period between establishment of the stand and final harvest, most silvicultural work is called timber stand improvement (TSI). Intermediate cuttings are at the heart of TSI. They are intended to improve the existing stand, speed the growth of crop trees, and sometimes provide early income for the owner. They are not cuttings made for regeneration purposes.
Intermediate cuttings are not difficult to understand. The tricky part is knowing how much to remove and how much investment to make in TSI before it becomes uneconomical. This will be discussed in the following chapter when we address the mechanics of caring for your trees. Before considering inermediate cuttings, we First need to look at the range of treatments and how they differ in what they can do for your woodlands.

Cleaning
This treatment is appropriate very early in the life of some stands. It is necessary when the desired seedlings or saplings are mixed with undesirable species that might become dominant. This often happens in young pine stands. They may quickly become overtopped by hardwood species if cleaning is not done. Selective chemicals area sometimes recommended for cleaning, but with enough energy and help, machetes or brush cutters can also do the job. The result is a young stand that is "clean," or free of undesirable species, at least long enough for the favored species to get a head start toward precious sunlight and soil moisture.

Thinning
Thinning is the removal of surplus trees from an immature stand, usually beyond the sapling stage. The idea is to concentrate growth on properly spaced, most promising future crop trees. It may mean the removal of the same species as the crop trees, or undesirables, or both. When trees are thinned too early in the life of the stand to provide a source of income, it is called precommercial thinning. Sometimes, however, thinning is a very important source of products such as firewood, charcoal, posts and poles. Since thinning is so important to good forest management, so potentially lucrative to forest owners, and so universally needed in North American forests, it is covered in some depth in the next chapter.

Improvement Cutting

Improvement cuttings are made to improve the stand by removing undesirable species and trees with defects in shape or condition. Terminology muddies the water, since an improvement cut also provides many of the benefits of a thinning. For all practical purposes, the operation is often one and the same. Improvement cuttings are usually needed in stands that have been neglected, which is common in small, privately owned woodlots.

Other Intermediate Cuttings
There are other intermediate cuttings that can become important depending on local conditions and the species involved.
Weeding is the removal of all woody or herbaceous growth that may be competing with desired seedlings. It is no different than agricultural or garden crop operations and is usually done in nurseries, Christmas tree plantations and similar intensively managed operations.
A liberation cutting is the removal of older, overtopping and inferior trees from a stand of younger trees. Sometimes the large, overtopping trees are called "wolf trees." In areas where wolf trees are scattered and of low value, they may be girdled and left to die in place as illustrated. This is a quick and inexpensive technique, and while the dead tree yields its light and soil moisture to the younger crop trees, it continues to provide and a perch for birds of prey.
Sanitation cuttings are sometimes necessary to remove diseased or insect-infested trees in order to prevent spread. If the infestation kills commercial-sized trees, a salvage cutting may be necessary. This is an unplanned harvest to make the most, economically, of an unfortunate situation. Forest fires, ice storms, hurricanes or other disasters may also make salvage cutting necessary.
Pruning can technically be considered an intermediate cutting even though only branches, rather than entire trees, are removed.

Harvest Cuttings
Harvest cuttings are one of the most controversial aspects of forest management. They are also the main difference between modern forest management and the days of rape-and-run timber barons. Ideally, the harvest cut can also be referred to as regeneration cutting, for the intent should be as much to provide for the new stand as it is to make a profit from harvesting the old.
A bewildering array of questions need to be answered before an intelligent choice of a cutting method can be made. Controversies on public lands continually result from ignoring some of these questions. On small, private lands, the problem is often that the forest is not large enough or in the right condition to permit one kind of cutting system rather than another, or that the owner is simply unaware of all the choices. On both public and private land, this results in more weight being given to immediate economic considerations than to the others, which fundamentally is no different from what happened when the timber barons roamed the land. When immediate, maximum income becomes the driving force, silviculture crumbles. The trees are cut and sold, and the land is sold or neglected. At best, the forest faces a long period of recovery, ugliness and unproductivity.
For the landowner who wants to balance cash income with other benefits, careful consideration should be given to the choice of a method for harvest cutting. There are four principal systems, all with variations or combinations. In their simplest form, they are described next.

Clearcutting
Used correctly, clearcutting is a legitimate and useful silvicultural method. European foresters have used it for centuries to provide a sustained flow of wood products, and it is popular with American and Canadian foresters in the great coniferous regions of this continent. As a cutting method, it is less popular with the general public, as witnessed by the explosion of public outcry when clearcutting was tried in the hardwoods on the Monongahela National Forest of West Virginia beginning in 1954.
With enough land and under ideal conditions, clearcutting small parcels one at a time can be considered a method of sustained yield forestry. That is, by the time the last trees in the property are cut, trees on the first harvested parcel have reached maturity. Usually, only the government and large forest industries have areas of land large enough to support this type of management.
Clearcutting, however, that is not intended as part of a continuously yielding forest is still an option. That is, all or part of your land might be clearcut with the realization that a long period of time will pass before a mature crop is again ready for harvest. In the southern pine region, this may be as short as 20 years for a yield of pulpwood (less in the case of hybrid poplars), but in most other regions it will take much longer.
One of the two biggest disadvantages of this method, especially in highly visible hilly areas, is the aesthetic impact. The second is the problem of getting seedlings established quickly so they are able to cope with the invasion of grass, brush and undesirable tree species that are typical on clearcuts. Both can be prevented. The first requires the careful design of cutting boundaries to reduce the unnatural appearance of straight lines, and the avoidance of highly visible prominences or hillsides facing living areas. As for successful regeneration, intensive management (site preparation, planting, weeding, cleaning or thinning) must be considered part of the responsible use of this method, even though it may be expensive and time-consuming in the years following the harvest cut.

Clearcutting Advantages.
1. Best for regeneration of shade intolerant species. (e.g.: Douglas fir, oaks)
2. Concentrates logging in time and location, making it more economical (high immediate income).
3. Damage to remaining trees from logging, windfall or other environmental factors are not a problem.
4. Best for converting an area to a different species (e.g.: from hardwood to pine).
5. Economical way to regenerate species needing fire as part of its management (to open cones, control disease, etc.(e.g.: jack pine, lodgepole pine).
6. Economical way to regenerate species with light, wind-blown seeds available from edges of clearcut. (e.g.: yellow-poplar, paper birch, loblolly pine).
7. Easy and economical to plant.
8. Simple and easy to plan and supervise; minimum of technical decisions.
9. Excellent for birding and for many forms of wildlife.
10. Provides forage for livestock.

Disadvantages.
1. May be aesthetically unpleasant.
2. Usually no merchantable products for a long period of time.
3. Invites the invasion of grass, weeds, shrubs and aggressive tree species that may be unwanted.
4. Changes microclimate, increasing impact of wind and extremes of temperatures.
5. May create short-term (3 to 5 years) erosion problems, especially in fine textured soils such as clays. The risk of landslides and snowslides may also be increased.
6. Under some conditions, large amounts of logging wastes may create risk of fire, insect or disease problems before slash disposal can be carried out.
7. If relying on natural regeneration, there is a high risk that seeds will be inadequate to start the new stand, or be unevenly distributed.

Seed Tree Method
The seed tree method is essentially a clearcut in which a scattering of selected trees is left to assure a seed crop of regeneration. A few years later, these parent trees are harvested. Depending on the species and characteristics of the site, from 1 to 10 trees per acre are usually left, representing something less that 10 percent of the merchantable volume. Since they will be the source of the future stand, proven seed producers with the best genetic attributes (height, form, vigor) are selected.
One variation of this method is to allow small groups to remain instead of scattered, individual trees. This helps with the problem of wind blowing over isolated trees and may help guarantee cross-pollination and seed production.
A second variation is to leave trees with defects, then skip the future harvest of seed trees. This reduces damage to the new stand but requires extremely careful selection to be sure none of the seed trees have genetically-linked defects. That is a difficult distinction to make. Another advantage of this method is that it provides trees for woodpeckers, songbirds and birds of prey.


Seed Tree Advantages...
1. Same as clearcutting except a seed source of the preferred species is assured.
2. The supply of seed is more uniformly distributed than in clearcutting.
3. Genetically superior parent trees can be selected.
4. Income can be spread over two periods; there will also be some volume increase on the trees left temporarily for seed production.
5. Slightly more aesthetic than clearcutting, and beneficial to a wider range of wildlife.

Disadvantages..
1. Mostly the same as clearcutting except for improved seeding and less risk of needing to plant.
2. Because of shock and windfall, there can be a loss of merchantable lumber before the follow-up harvest.
3. Cannot be used in shallow soils, with shallow-rooted species (Ex.: spruces), or with species having wood of low strength (Ex.: eastern white pine).
4. Restricted to species that produce large numbers of light seeds, and that are able to germinate and grow in open conditions (Ex.: longleaf and most other southern pines, yellow-poplar).

Shelterwood Method
The shelterwood system combines some of the advantages of clearcutting with those of the seed tree method, and adds some of its own. Consequently, it is a rather popular method with considerable flexibility to meet the needs of many species and sites, as well as the landowner's objectives.
The best application of shelterwood cutting is with species that need partial shade in the early stages of their growth. By adjusting the number of seed trees that are left in the canopy, the amount of shade can be regulated to meet the needs for successful regeneration of the desired species. The older trees are not only a source of seed, they provide shade and shelter for seedlings and protection for the site. Also, when viewed from a distance, a more natural appearance is retained until a new stand is well on its way toward replacing the old.
This system has at least three steps, all of which yield saleable products and spread income over a period of 10 to 20 years.
The first step is a preparatory cut. Similar to a late thinning, the intent in this cut is to remove weaker trees and provide more growing space for future seed trees. About 25 to 30 percent of the trees are removed. This allows the remaining trees to spread their crowns and increase their root systems, thereby becoming more windfirm and generally more vigorous. A side benefit, of course, is that they will also put on more wood volume and increase in value. Usually, 3 to 10 years are needed for the desired results.
If continuous thinning has been part of the history of the stand, the preparatory cut in the shelterwood system may be omitted. On the other hand, in thick, neglected stands, two or more preparatory cuts may be necessary before nicely spaced; vigorous seed trees cover the land.
The second step is the seed cut. This removes all but the very best seed trees and simultaneously opens up the canopy enough to allow seedlings to get established. The seed cut should be made in a year when the desired species produce an abundant seed crop. The best time for the cutting within that year comes after the seed has matured and before it is dispersed. Spacing of the parent trees might vary from 30 to 40 feet or more, depending on the species and site. Closer spacing will be needed in frost pockets or on south slopes; wider spacing is best on more favorable sites. The shade tolerance of undesirable, competitive species should also be considered. Previous local experience provides the best clues for fine-tuning this method of regeneration cutting.
The third and final step is the removal cut, or overstory removal. This is made after regeneration is assured, usually when the new trees are about waist high. If some final shading is needed, the removal cut can be made in two or more stages. However, this is uneconomical and increases the chances of damaging the new saplings when taking out the old trees.

Shelterwood Advantages.
1. Many the same as the seed tree method, but with even greater assurance of natural regeneration.
2. Protects site, seedlings and visual qualities of area. Can be used to meet specific needs, including controlling competition.
3. The first harvest cut also acts a thinning in that the seed trees have less competition for several years and can add significant wood volume.
4. Genetically superior trees can be selected to regenerate the new stand.
5. If markets are available, cash income is more frequent.

Disadvantages.
1. Unless regeneration is much too dense, logging, slash disposal and site preparation must be done with care to spare desirable trees.
2. Logging and management costs are higher.
3. Markets must exist for small-size logs as well as for lumber.
4. More complex than clearcutting or seed tree methods.
5. Only slightly better than clearcutting or seed tree methods for regenerating shallow-rooted species or stands on thin soil.
6. Requires roads to be efficient.

Selection Cutting
Selection cutting is what many people consider "ideal" forestry. In this method, individual trees or small groups are cut at continuous intervals as frequent as five years. This yields the closest thing to a regular income from trees, especially if they are of lumber or veneer quality. At the same time it can leave the woods looking whole and beautiful. Unfortunately, it is one of the most difficult methods to execute properly, and many people who think they are practicing selection cutting are actually "high-grading" their forest and reducing its future value.
In true selection cutting, the stand will contain all ages of trees. Perpetuating this condition is called uneven-aged forest management. German foresters think of it as the Dauerwald, or "continuous forest." Its advantages are obvious, but it is not without drawbacks. Being aware of these problems can help you practice this method correctly, or may help underscore some to the reasons why the even-aged methods are also "ideal" forestry under the right conditions.

There are two principal kinds of selection methods - single-tree selection and group selection.
In the single-tree method, each tree is examined and harvested as it matures or passes the "point of diminishing returns." This is when its growth slows to the point where more money would be earned by selling it at its current volume than waiting for more wood to be added. Usually this age is determined using the average of many trees in the stand. A specific diameter is then used as a guideline after this age has been determined. This guideline, however, must be considered flexible, as it is often beneficial to remove some additional trees below the diameter limit.
Essentially, the single-tree method combines harvest cut with improvement cuts and thinnings. The removed trees provide growing space for younger ones. Selection cutting is especially beneficial when trying to regenerate shade- tolerant species such as sugarmaple or beech in the East or redcedar in the West.
In group-selection, saleable trees of all sizes are taken from small areas of about ¼ to ½ acre. From the standpoint of logging, this is more economical than selecting individual trees. Man-hours and equipment can be concentrated in fewer places rather than being spread out over the entire forest. If small enough, the openings still protect the aesthetics and ecological diversity of the forest. However, when they exceed ¼ acre or their width is more than the height of the surrounding trees, they begin to resemble small clearcuts. When this happens, the greatest advantages of selection cutting may be lost.

There are two big problems with selection cutting. The first is the difficulty of balancing the volume of wood removed with the volume being added by the smaller, younger trees that are left. The second involves the kind of trees that will and will not be favored by such a harvesting method. Simply taking out large trees and making improvements cuts is not enough. As one forester said "affairs may drift aimlessly into chaos as a result of lack of attention to regeneration and distribution of age classes." This has happened in forests of every type in America. Owners have yielded to the temptation of taking the biggest and the best. They think it is selection cutting, but it is really high-grading. To do otherwise requires careful inventories, a sound knowledge of the site and the silvical characteristics of the trees, and accurate estimates of annual growth and yield. This is a tall order. In fact, some professional foresters do not have the skill needed for successful selection cutting. Also, many have a bias against selection cutting because of its complexity and problems.
Through study, high quality professional advice, and long-term ownership, selection cutting can work in many woodlots. For owners devoted to the Dauerwald concept of the forest as a single, continuous organism, further study of this method could result in a satisfying experience.
Selection Cutting Advantages.
1. Maximum protection of site and least alteration of ecological conditions.
2. Most aesthetically pleasing.
3. Excellent wind protection.
4. Reduces likelihood of devastating insect of disease outbreaks and wildfire.
5. Excellent conditions for many types of wildlife.
6. Allows shade tolerant species to be favored over intolerant ones, where desired.
7. Yields regular income and the simultaneous reduction of a variety of products ranging from firewood to lumber or veneer-quality logs.
8. By including high-value trees, may attract loggers who would not otherwise do improvement cuttings.

Disadvantages...
1. Logging costs are high because the operation is spread out and extra care must be taken to prevent damage. More skill needed.
2. Technically complex. Extreme care needed to keep volume of harvest in balance with annual growth and yield; restraint needed to prevent removal of trees too early or only those of best quality (leading to high-grading and genetic degradation of stand).
3. Income at any one time may be low to moderate.
4. Trees may have too much room, developing too much taper and too many limbs (knotty lumber).
5. Not well suited for shade intolerant species.
6. The risk of damage from logging to remaining trees is high.
7. A well-planned, permanent road system is necessary.

Coppicing
There are many other variations on the major harvesting systems, but coppice cutting deserves a special mention here. It is a technique that has been used for centuries in Japan, Europe, and other countries where small-wood products have been important. Early settlers in North America used coppicing in the hardwood forests for producing fuel wood and charcoal. Later this method fell from favor as coal and oil displaced wood as fuel. With today's return to the forests as a source of fuel, coppice cutting is a method worth thinking about.
Many species - especially northern hardwoods - have dormant buds hidden in the lowest parts of their trunks. This is survival insurance that allows trees to develop "vegetatively" rather than through seeds. When wind snaps off a tree or fire sweeps through a stand, the dormant buds close to the ground are triggered to life. Sprouts result from the stumps of the old trees, which in turn grow into new trees.
In coppice cutting, the stand is clearcut and sprouts are relied upon to provide the new forest. In some species, such as aspens, root suckers provide the same effect. For best results, the harvest cut should be made during the late fall or winter when the whole tree is dormant. Food stored in the roots is then at its maximum and can be concentrated in the sprouts when spring arrives. The resulting rate of growth can be quite spectacular, and the new sprouts are well established prior to the fall frosts.
This vigorous growth, combined with multiple stems developing from a single stump, can produce large quantities of trees of firewood or pulpwood proportions in 10 to 20 years. In fact, the main characteristic of this method is its short rotation period. Usually, trees grown from seedlings have much slower initial growth. For rotations over approximately 40 years, the advantages of sprouts give way to those of seedlings. Not only does sprout growth slow at an age when seedling growth gains, rot more easily enters coppice sprouts, resulting in spotty or inadequate distribution of mature trees. Also, the straighter trunks of seedlings may add to the quality of trees destined for lumber or veneer. In fact, when planting is intended as the source of the future forest, stump sprouting becomes a curse. Herbicides, summer logging, or mechanical methods must be used to control the sprouts that would otherwise quickly overtop the seedlings.
Coppicing is best suited for the production of firewood, charcoal, pulp, or small products such as mine props, posts, garden stakes and willow rods. It works particularly well with poplars, oaks, black locust, red maple and redwoods. Most hardwoods will sprout, although some, like beech, cannot be depended upon to reach tree-size. In some cases, such as in red maple or willow swamps, coppicing may be the only logical way to regenerate the stand.
The ability of a tree to produce vigorous sprouts after being cut diminishes with age and diameter. Stands being considered for coppice cutting should be relatively young and growing rapidly.
The biggest argument against the use of coppicing is that there are usually more economic advantages in allowing rapidly growing trees to grow than in cutting them. Usually enough firewood, posts and other small products can be obtained from thinnings or improvement cuttings to justify leaving the best and most rapidly growing trees for later harvest at higher prices. Still, under some conditions, coppice cutting is a harvest method to consider.

Disadvantages...
1. Same as clearcutting except for faster regeneration.
2. Must have good market for large quantity of small-diameter products.
3. Thinning is often required.
4. Not recommended in frost pockets, at high altitudes, or in very cold climates. (Sprouts continue growth over the whole summer and the entire season's growth can be lost due to early frosts.)
5. Not suitable for growing quality timber trees because of rot potential, crooked butt logs, and other problems.