FOREST REGENERATION AND IMPROVEMENT

~Presented by Hampton Affiliates

Forest Regeneration

Today in forest land management, the forester must plan ahead for the next timber crop before the present crop is harvested. Thoughtful plans are made for the next crop to be regenerated by natural or artificial methods of reforestation.

The first action the forest manager must take after the harvesting operating has taken place is preparing the logged-over area for reforestation. This is called "Planting Site Preparation.' When the logged area is to be artificially regenerated the logging slash and debris will either be burned with a controlled slash fire or chipped and mulched. When natural regeneration methods are to be used, the logging slash is fire-trailed and left to decompose.

Natural regeneration of a forest can be achieved by leaving uncut patches of mature tree seedlings or aerial seeding with tree seed upon the clear cut area.

Tree seedlings raised in the nursery are grown in field beds and grow two to three years before they are large enough to transplant in the clear cut areas. These trees are called "bare root seedlings" because when they are lifted from the nursery beds the soil is washed from the roots to ease packaging and transportation to the planting sites in the forest.

In recent years a new method of growing tree seedlings has developed. These seedlings are called "container trees". Container trees are grown in greenhouses under controlled environments. The container trees are grown one year and are large enough to transplant in the clear cut areas. These trees are transported and planted with soil intact with the roots which reduces transplanting shock.

Planting of tree seedlings on low elevation areas takes place in the late fall and early spring. The higher elevation areas are planted in early fall and late spring.

When the regenerated plantations are established, the forest manager must manage and protect them for 60 to 70 years until the next harvesting operation. This will require protection from fire, insects, disease and animals as well as eliminating unwanted trees or vegetation that will compete with the planted trees for sunlight, soil moisture, and soil nutrients.

The young tree plantations will be precommercially thinned or weeded between the ages of 10 to 20 years and commercially thinned between the ages of 30 to 60 years. The plantations will be fertilized several times throughout their growing period.

Forest Improvement

It is possible to improve forests through the selection of the best seed for production of new crops of trees. Genetics involves qualities which may be inherited from one generation to another and it applies to plants as well as animals. In a general sense, the biggest, best formed and fastest growing trees may produce seed that will grow into trees which are similarly big, well-formed and fast-growing. Through the selection of the proper seed from parent trees it will be possible to, eventually, produce planted or seeded forests which should produce more wood of better quality than the natural forests we now have.

Parent trees are selected primarily on the basis of form, growth rate, disease resistance, and since seed is the goal they must also be selected for fruitfulness.

Seed may be collected from the parent tree by climbing the tree and collecting its cones, this however is sometimes very difficult and costly on a yearly basis due the trees large size or its location in the forest.

Another method of obtaining desired seed is through propagation of selected parent trees from vegetative shoots, thus reproducing their genotypes exactly. This is accomplished by collecting small branches (scion) from parent trees and grafting the scion onto a rooted tree (rootstock) in such a way that the cambial layers are in close contact and can grow together. Grafted trees can then be planted in desired locations and will have the same genetic characteristics as the parent in which the scion material was collected. This is known as a Clonal Seed Orchard. Grafted trees in a seed orchard may start producing seed within 2-3 years.

Further improvements of the seed can be accomplished within the seed orchard through pollination. Controlled pollination is the artificial transfer of pollen from one flower to another under such conditions that both parents are known.

The seed from controlled pollination can then be planted, and these improved seedlings tested to determine which selected parent trees produce the fastest growing, well formed trees. The inferior growing parent tree grafts can then be removed from the seed orchard leaving only the best grafts for seed production.

Other Forest Improvement practices that can improve forest yield and quality are list below:

1. Thinning
   Thinning involves the cutting of a part of the forest so that growth will increase on the remaining tree. This is accomplished by eliminating the tree's competition for limited amounts of lights, water and food.
2. Weed Control
   There are various trees and shrubs in a forest which have no commercial value and they also compete for the light, water and food within the forest that the trees need for growth. These undesirable trees and shrubs can be eliminated through the use of chemicals or by mechanical means. Sometimes, large areas of land may be covered with these undesirable plants and, in such cases, bulldozers may be moved in to clear than away and a new crop of trees started through planting. At other times, these plants may grow faster than a new crop of trees and they can then be eliminated with a chemical spray applied either by helicopter of by a small back-packed spraying machine.
3. Pruning
   Knots in lumber come from limbs that grow out from the center of the tree. If limbs are pruned, the stub ends grow over and clear wood is produced. This makes a high quality (and more valuable) lumber. In close grown forests this pruning occurs naturally but hand pruning can sped the process.
4. Fertilization
   When applied at the proper time, fertilization of the soil can improve the yield of a forest by increasing tree growth. Fertilization can also improve the quality and color of trees grown to produce Christmas trees.