Sustainable Silviculture and Selective Forest Management

Selection Cutting by Diameter

This method produces an irregular forest mass. It is often referred to as "diameter selection" rather than a standard harvest.

The process involves cutting individual trees or small groves of mature trees within each stand where it intervenes. At the same time, the intervention is used to relieve, improve, clarify, and restore denser clumps, representing more precise silvicultural work.

While the method is involved in each stand at a time, only one type of silvicultural work is performed within each specific clump:

• Selection regeneration
• Selection intermediate
• Selection release and improvement

This approach serves the dual purpose of regeneration and improvement.

When the headquarters or management area is large enough, it is divided into several "sections of high grading" based on annual or periodic rotations of the selection cut. Usually, a rotation of thinning or frequency of intervention is established on the same stretch every 10 to 15 years.

Ideally, the thinning rotation should be sufficient for the dominant trees in each grove to grow approximately 5 cm, effectively skipping to the next Diameter Class (CD). If the number of thinning sections is equal to the rotation period, interventions are conducted annually.

By dividing the cutting diameter by 5, you determine the number of diameter classes. Ideally, within each mountain, reach, and stand, all diameter classes should be equally represented. This means each CD will cover a surface area calculated as: Surface Area / Number of Diameter Classes.

Selective Logging and Protection Forests

Selective logging is a primitive form of forestry. Currently, it is considered appropriate for protection forests, though it is also applied to tropical forests. In each intervention, only commercial trees are cut.

This method is secured to the ground in front of fire hazards, following the principle: "It takes what it's worth before it is lost."

Single-Tree Selection and Thinning

This technique, also known as "thinning foot to foot," sets a strong sense of maturity that goes beyond purely commercial interests. It limits the amount of wood extracted and allows for various silvicultural treatments to be performed simultaneously.

Mature trees are cut and spread, opening small gaps of no more than 100-125 m². This ensures the cut is minimized and maintains a maximum natural feel.

• Interventions are not based on surface area but on a careful diametric inventory.
• This requires complex management.

Ideally, the goal is to cut a number of trees each time equal to those incorporated into each diameter class since the previous rotation.

Group Selection in Irregular Forests

In selective woods management, trees are harvested in small groups or clumps ranging from 0.5 to 5 hectares. The forest, its sections, and all stands will eventually be composed of small clumps, creating an irregular mass from regular groups.

Each thinning rotation regenerates a total number of clumps of a certain average size. The regenerated surface (the sum of all woods in installments) should be equal to the upper section divided by the number of diameter classes. Annually, cutting the same area would correspond to a clearcut, but in this system, it is scattered throughout the stands and individual trees.