HOW TO CARE FOR YOUR SMALL FOREST

M. M. BRYAN.

To care for your small forest, know first your goal.

A good small forest has needles, leaves, twigs, and small branches on the ground, a mat that absorbs water and keeps the soil from washing away. Under the litter is a layer of humus, usually dark-colored and rich looking.

A good woodland has no damaged and diseased trees. Poorly formed and overripe trees have been cut out, so that good ones have room to grow. Remaining are well-formed trees that are suited to the locality, the soil, and the climate, and that will make high-quality products.

The forest floor has little sunlight: If all trees are the same age, grass and young trees cannot grow under them because there is no sunlight; in a mixed-age forest, there will be little trees just sprouting, seedlings of various sizes, and large, mature, or nearly mature, trees. If your forest is in the West or South, it may be more open, and may even have some grass or plants under the trees.

The good forest has enough good trees, neither too many nor too few. If your goal is to grow Christmas trees, the ground will be covered. If you are a turpentine farmer, a few hundred trees per acre are right.

No matter what forest product is being grown, the crowns of the trees will be full and healthy; about a third of the total height of each tree will have branches and leaves. If the trees are all about the same age, the canopy will be closed in the form of a ceiling. If the trees are of all ages, there will be no continuous ceiling of foliage.

Trees close together usually grow tall and straight. They are trying to get light. Lack of sunlight on the lower branches causes them to die and break off. Thus, a healthy tree prunes itself and produces clean and straight logs, without too much difference in size between the butt and the top of the last log.

Wildfire and grazing animals have no place in a good forest. In some western and southern forests, a little grazing is possible. Hogs are kept out.

Several rules of good management will help you grow good trees.

1. Make improvement cuttings; remove the undesirable trees so that the better ones can grow faster. Usually several improvement cuttings are made before the final product is harvested.

Often the products removed will pay: Fuel wood can be cut from the poorer trees, railroad ties from short, forked trees, and even some sawlogs for home use. The good trees that are left are called the crop trees.

If each acre is adequately covered or fully stocked with the better hardwood trees, the forest should grow from 1/2 to 1 cord of wood a year on each acre. In the small forest of good pine, growth will average from 1 to 2 cords an acre a year perhaps more in the South.

2. Thinnings should be made whenever the tops of the trees become crowded or when many dying branches appear an indication that the trees want more room to grow. Often young seedlings become crowded; when they are thinned, firewood, pulpwood, bean and tobacco poles, and fence posts can be removed. In a few years another thinning can be made to yield mine timbers, small poles, pulpwood, railroad ties, more fence posts, and a few sawlogs.

Weed trees should be cut. Blackgum, chokecherry, scrub oak, or other less valuable trees may crowd out better trees.

Thinning also removes the excess of young trees; often the unwanted small trees can be cut about halfway down and the tops bent over. They continue to live and, by shading the ground, make the better trees grow tall and straight.

When to thin is important. Usually thinning is needed:

(a) In young, fully stocked stands when about 15 to 20 years old;

(b) in the young stands that have stopped growing or become stagnated;

(c) when the crowns of young trees are crowded and many dead branches occur;

(d) when an interval of 5 to 10 years has passed between thinnings and the trees again crowd each other.

How to thin is sometimes more difficult than knowing when to thin.

A single thinning should not remove more than one-quarter of the volume in a stand.

Yellow-poplar, cottonwood, sweet-gum, loblolly pine, slash pine, and any fast-growing trees can be thinned more heavily than trees such as white oak, basswood, and ash.

For southern pines and hardwoods the rule of thumb called D+6 is often used. For example, the diameter at breast height of one healthy tree is 10 inches and the diameter of the other healthy tree is 6 inches. Added together and divided by 2, the average diameter of the two crop trees is 8 inches; 8 inches considered as 8 feet, plus 6, equals 14 feet, the proper spacing between crop trees of this size.

In the West, the rule D+4 can be used for spacing crop trees of ponderosa pine. Other species may require different spacing and local advice may be needed in such cases.

Good sense is needed in thinning the small forest. Following a rule may result in thinning a clump of 6 to 10 good trees to only 2 or 3, when actually it might be better to cut only 2 or 3 trees, which will give the clump plenty of room to grow.

When a fast-growing young tree is directly under a mature tree that is soon to be cut, the young tree should be left for a future cutting.

Consider each tree individually and determine its chances of growing into good timber.

3. Liberation and salvage cuttings are part of the care. Wolf trees large, branchy individuals with spreading crowns often keep down the more desirable little trees that should be growing for the future. Forked, knotty, crooked, and other poorly formed trees also take up space needed by better seedlings and saplings. Diseased, rotting, as well as insect-infested trees will probably die before they can be cut into fuel wood or fence posts; they should be removed by poisoning or by girdling with an ax.

The undesirable hardwood trees and sprouts can be poisoned successfully with Ammate (the trade name for ammonium sulfamate). This poison can be applied close to the base of the tree. Chip out small cups in the tree trunk with an ax at 6-inch intervals around the tree. Place 2 level tablespoonfuls of Ammate crystals in each cup for trees 4 inches in diameter and over. For trees under 4 inches in diameter, 1 tablespoonful a cut is enough. Leave the trees to die; they should not be girdled or cut down because sprouting might occur. After a year, it is generally safe to cut the tree down if you want to. Use the poison in late summer or early fall. A 32.5-percent water solution of Ammate sprayed on green leaves will kill small trees and sprouts of undesirable species, such as blackjack oak.

Other poisons, obtainable from seed houses, are used for killing undesirable trees and shrubs like the persimmon, blackgum, and sweetgum.

Vines growing on trees kill them by shading or bending. Protect the crop trees by cutting the vines off at the ground.

Usually it is best to make a liberation cutting in early summer; sprouts from fresh stumps are less likely to appear then; and, it is easier to see which trees to cut.

Salvage cutting means removing the overripe trees that are growing too slowly to be profitable. Overripe trees are usually recognized by their light-colored bark, flattened crowns, and thin foliage. They should be cut and made into useful products before they are attacked by insects, disease, or are otherwise damaged. The thrifty, fast-growing trees that are damaged by fire, insects, disease, winds, or lightning should be salvaged while the wood is still usable.

4. Pruning the trees frequently increases their value.

In considering whether to prune, you should determine whether or not better prices will be received for the product to be harvested.

Local advice may be helpful and certainly is needed if any question arises as to the best time for pruning and how to go about it.

Prune only the vigorous and healthy crop trees.

Select about 200 to 225 such trees on each acre.

Prune trees the first time when they are from 4 to 6 inches in diameter. Cuts heal rapidly on these young trees and the knots will be small.

Prune in early spring just before the growing season begins.

Make clean cuts close to the trunk of the tree. A long stub may rot and later cause the tree to decay or be attacked by insects.

At any one pruning, remove no more than the lower third of the branches that make up the live crown of the tree.

Removal of too many live limbs will slow down the growth of the tree for several years.

After the trees have grown larger, another pruning up to 16 feet in height or for two clear logs may be desirable.

The best tool to use is a pruning saw with a 12- to 18-inch blade, 3 1/2 to 5 1/2 points to the inch. A ladder and hand saw can be used for the high branches. Some prefer a pruning saw fastened to a long pole. Do not use an ax.

Work safely; a falling limb is dangerous; ladders should be firmly placed against the tree.