Wood is one of those building materials that have been known to mankind since ancient times. The volume of its consumption is growing every year, and therefore many species are on the verge of extinction.
The latter also includes the cork tree, which has been used by man for thousands of years.
It belongs to the genus of oaks. The difference from relatives is that by about five years of age, its branches and trunk are covered with thick bark with unique properties. But you can only take it off by the age of 20. Note that you can do this up to the age (tree, of course) of 200 years!
After the first collection, at least 8-9 years are required, during which the bark is restored. A tree aged 170-200 years produces approximately 200 kg of high quality raw materials.
The peculiarity of this oak is also that it belongs to the evergreen species. The leaves resemble those of Russian oaks, but are covered with a significant layer of down below. The cork tree itself is quite large: the height can reach 20 meters, and the diameter of the trunk is a meter.
Latin name - Quercus suber. It grows at an altitude of no higher than 500 meters above sea level. Moreof all oaks of this species is found in Portugal, which is why the country's budget receives considerable cash injections from the export of cork, which annually increases its value.
Man has known since ancient times that the cork tree provides this most valuable raw material, and therefore it has long been cultivated culturally. Note that there is a false representative of this genus, Q. crenata, which is quite widespread in southern Europe. Its cork layer is so small that the tree is bred exclusively for decorative purposes.
Only in Portugal more than 2 million hectares are occupied by Quercus suber oak plantations! In addition, approximately the same number of territories are used for this in all of Southern Europe.
For a year, all plantations produce more than 350 thousand tons of bark, but this amount has long been insufficient to meet demand. That is why the wild cork tree was almost completely destroyed.
By the way, what is the uniqueness of cork as a material? The fact is that it is a natural polymer, the structure of which resembles a honeycomb in a bee hive.
Each cubic centimeter of this material can contain up to 40 million of these honeycombs, which are separated from each other by cellulose component partitions.
Simply put, each capsule is filled with air, so even a small piece of cork is very elastic. This property gives the material complete waterproofness and the ability to restore its original state even after strong pressure.
That is why the cork tree (whose photo is in the article) has received such wide appreciation from furniture makers.
In addition, the bark contains suberin (a mixture of fatty acids, waxes and alcohols). It is unique in that it gives the tree refractory and anti-rotten qualities. There are cases when, during forest fires, cork oaks remained completely intact, except for the scorched bark and leaves dried from the heat.
Thus, cork tree bark is a unique material bestowed on man by nature.