The forestry development is a production process applying to a whole of Arbre S for their routing towards a site of valorization.
Forestry development and sylviculture
The management of the Forêt S is the base of the Sylviculture. A well managed forest will be exploited according to a plane management of the forest. This plan of management includes the system of sylviculture which will be used: system of installation équienne or inéquienne, provision of the road of exploitation, and in the case of a selective cut the marking of the trees with to cut down.
Methods of harvests
The operations of demolition can be carried out according to three methods:
In big length The trees are cut down then pruned and topped on the spot. The Grume is then transported in the delivery point where it is cut up and charged on a truck. This method leaves the Rémanent S on the zone of cut.
Out of whole tree The trees are cut down is transported directly in delivery point where only they will be pruned and cut up. This method leaves a great quantity of remanent on the delivery point.
Of wood runs The trees are cut down, pruned, cut up and sorted on the zone of cut, leaving the branches and the houppier in the forest.
Operations
A wood harvest includes/understands the following operations, but not necessarily in the order given:Pre-demolition
- Planning : Identification of the optimal timing, the access and the installation of harvest.
- Authorization : Notification with the public, environmental evaluation, payment of taxes.
- Marketing : Many landowners employ their clean loggers, while others rent or sell the right of exploitation with a forest company.
- Access : Cart track farm, camps forest, stations of weighing are built if necessary.
- Marking : The zones or trees with being collected are clearly identified.
Operation of demolition
- Demolition : The tree on foot is cut using a Tronçonneuse or of a Abatteuse.
- Treatment: The transformed tree is pruned and cut up.
- Unloading : Wood is moved stock with the deposit. Vehicles can draw, transport or flush out. A system of cable can draw the barks to the delivery point. It can also be transported by Hélicoptère (very rare).
- Transport: Wood is transported to a Scierie or a port, in general by truck but also by train, floatation towards the downstream of a river or is drawn by boat.
Post-demolition
- Burning : Burning remains of the demolition and another reduced wood of the future fire hazards.
- Release : Elimination of concurrent vegetation to increase the growth of the planted trees.
- Afforestation : Seed spreading or manual planting of seedlings of trees.
- Destruction of the roads : The erosion and the landslides due to old roads of exploitation can be considerably reduced by installing stoppings with water and by pushing back the material excavated such as it was in the beginning.
Unloading
The Débardage consists in dealing with the Arbres (whole or in the form of Billon S) since the place of cut to the surface of deposit. In certain situations, it is carried out in two times and one then distinguishes the débuscage and drains it.The first stage, the débuscage, consists in drawing the trunk to the track or the carrying cable. This stage always does not take place in Europe, but it is almost systematic in Africa. In the tropical forests, one uses to carry it out machines of the type bulldozer Caterpillar D7G. Then, draining, will consist in bringing the bark until a place accessible to the trucks.
The unloading is currently carried out by machines, the horse is still in service nowadays, in particular in the the Belgian Ardennes where one counts approximately 350 Chevaux. In Asia, the elephant is also used. Always among the techniques with the ground, one hopes to dévaloir it who is useful in mountain. The principle consists in setting up a kind of giant toboggan by which the balks can go down.
Draining can be done by the airs using cables, it acts of telepherage. This technique is used in the event of strong slope or of grounds with weak bearing pressure. In a more marginal way, the Hélicoptère can be used in the mountainous areas for the wood of high-quality but proves to be the most dangerous method and least profitable.
Operations on surfaces of deposit or edge of road
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Handling of the products (cutting, sorting…).
- Treatments of safeguarding.
Forest roads
The forest roads are built to provide an access to the forest for the forestry development and other operations of management. They are generally dirt tracks.These ways play of the multiple roles in the main forests. They are a means of valorization of the forest by offering an access to the machines of exploitation and the loggers, for wood-cuttings or the breaks then for the Reboisement. The forest agents also use them to supervise the evolution of the settlements, to carry out inventories… These ways are very useful for the fight against the forest fires. The public can also use them for walks and discover the richness of the ecosystem.
The construction of these ways, especially on the steep slopes, can increase the erosion and the landslides, which increases the Sédimentation downstream. The ways are generally the most important source of sediments of the operations of exploitations, which can continue a long time after the end of the operations in the zone. However, of the methods are often used to limit these effects such construction of ditches. The déconstruction of these roads implies to restore the natural habitat, and is generally more expensive than the cost of construction.
Forestry development and environment
; Effects negative The forestry development impacts the Environnement at the same time by removing trees and by the disturbances caused by the operations of demolition. The removal of trees deteriorates the specific composition, the structure of the Forêt, the ground, and can cause an exhaustion of the ground.It can also lead to a loss of a habitat, particularly in the ecologically significant zones. The machines used often disturb the ground, heaviest can cause a compaction of the ground. The exploitation on steep slope can cause a erosion ground, landslides, a Turbidité of water. On water-logged soils, it can create rut S and disturb the drainage. The tree felling close to river can cause the increase in the Sédimentation, the temperature of water and degrade the riparian habitat .
A forest managed mainly for the production of wood will consist typically of young, vigorous trees and with rapid growth. Such a forest can miss zones with characteristics of old forests, like old trees required by some species. A good management of forest requires that such zones are put aside to protect from the rare species or in danger.
; Positive effects The forestry development has also positive effects on the Environnement by the suppression of damaged trees or patient, by opening the Canopée to promote the growth of smaller and operational trees. The nonmarketable branches and other parts of the tree provide a shelter for part of the fauna. The undergrowth, which differently could not have grown for lack of light, thrives, and it is an important source of food for the herbivores. A selective cut can improve the forest and bring on the market of the wood which differently would have broken up. The new projections in stocks make it possible to reduce the formation of ruts and the disturbance of the ground. power-driven circular saws and carrying on legs with broad feet make it possible to reduce to the maximum the impoverishment of the soil.
See too
External bonds
- Unloading with horse in hot area
- Document ONF on the practices forest (pdf)
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