Undergrowth
With undergrowth is called the growth of forests below the treetops . It mostly consists of shrubs or small trees. These can be planted, but they can also have developed from root runners , stick rashes or seeds from older trees. In some commercial forests , undergrowth is undesirable because it competes with large trees for food and hinders work on the area (e.g. thinning , wood harvesting or caring for large trees).
Today, however, more and more people are consciously planting rejuvenation as undergrowth, so that the sprouts can grow under the protection of the old trees and there is no clear-cutting when the old trees are harvested. For ecological reasons, too, such a multi-layered forest of undergrowth and upper wood is welcomed.
In the course of near-natural silviculture , natural rejuvenation of the old stand is increasingly being sought in Germany . This saves the effort of planting or sowing. In order to achieve this, the top wood is thinned towards the end of the rotation period at the latest , i. H. some of the old trees are harvested. This way, more light reaches the forest floor and the seeds of the old trees can germinate and grow into undergrowth.
However, natural regeneration only works if game browsing can be kept low through increased hunting, especially for roe deer , and the old stock is cleared as the undergrowth continues to grow. Natural regeneration also only makes sense if the old stand contains the desired trees for the future stand. If, on the other hand, a forest stand is to be converted, e.g. B. a pure coniferous forest into a deciduous forest or mixed forest , the regeneration, i.e. the undergrowth, must be artificially introduced.
Another form of undergrowth is the "serving tree". For this purpose, a secondary tree species in the shelter is added to the main tree species in the upper part. This should then not take over from the upper tier, but rather keep the trunk of the main tree species as dark as possible with its treetops so that no side branches form.
Classic cases are stocks of veneer oak .
