2. Trees stand development

3. The forest is born,matures and dies. It will take several decades before it reaches full maturity Foresters, whose work is multigenerational, are responsible for the entire production cycle. Let's take a look at their work.

4. Sexual reproduction It is important to plant trees, which were grown from seeds with the best genetic features. It is common to establish a plantation from which in the future the best seed material will be obtained. The seeds can also be collected from trees which grow naturally in the forest stand.

5. Seeds Mature trees produce seeds – some of them every year, and other at intervals of 5-10years. If the seeds are on a fertile soil, they germinate and in the right conditions they turn into seedlings, which in the future will have a chance to become a mature trees.

6. Forest nursery

7. Natural reforestation

8. Forest cultivation It is difficult to renew the forest naturally, so foresters use nurseries's help where seedlings are produced. Planting trees results in so called growth The trees are planted in large numbers which may reach up to 10 thousands pieces per hectare.

9. Sapling stand Sapling stand is a result of artificial or natural renewal. Its identifying attributes are: strong competition with other trees and strong crown cover. In this phase, trees grow up fast. Foresters help the trees to survive. They remove trees which obstruct trees with better features. During this stage number of trees per 1 ha is reduced about 50% This period may take up 10 to 30 years depending on the species. This is the time of the natural purification of branches.

10. Small pole This stand is about 20 to 35 years old. The diameter of trees does not exceed 10cm. At this stage, the trees intensively multiply their height and at the same time form a negative ratio of their thickness to their height.

11. High pole Trees which create so called high pole are 35 to 50 years old. At this stage, the thickness of the stand increases faster than its height. The next step is cutting the weakest trees down to maintain the health of the stand. This loosens the density around the best trees. At this time, the number of trees is about 500-600 pieces per hectare, depending on the species.

12. Maturing stand Trees are approximately 50-80 years old. At this time, they begin to produce seeds. Trees do not increase their height intensively, but they still increase their thickness.

13. Mature stand At this stage trees do not grow up as fast as before, but still maintain the increase of their thickness. The diameter of these trees is usually about 35-50cm. Such forest is regarded by foresters as mature for cutting down. Age of this forest mainly depends on the species and ranges from 100 to 160 years. The number of trees per hectare is about 300-400 pieces.

14. Overmature stand Such a stand is over a 100- year old with a trunk's diameter of more than 50cm. In this phase, it begins to die down. The wood gained from these trees is not worth much because destructive processes lower its value. Such stands are rare. Some of them are protected as ecologically valuable.

15. As you can see, life cycle of a tree is not short. Despite the growing acquisition, which in 2013 amounted to 36 286 thousand cubic meters of timber. The forest cover in Poland increases each year and by the year 2030 forest cover is expected to be 33% area of the country. If we want to obtain the raw wood in the future, we have to plant trees today.

16. Thank you for watching the presentation. The presentation has been prepared by : Kamil Koziński Jarosław Daglis Hubert Czelewicz Music – „XX Intro” Photos made by authors. Technikum Leśne w Warcinie im. prof. Stanislawa Sokołowskiego