The young layer of wood, located directly under the bark, is sapwood (also called sapwood, underbark, blon). It is considered less resistant to attack by insects or fungi, and also has low strength and contains a lot of water, compared to the ripe inner part of the tree and the core. In nature, there are such tree species, the wood of which consists entirely of sapwood, for example, aspen. A thick resinous mass is deposited in it - resin, which is obtained by making cuts in the bark on coniferous trees.
Structure of wood
Wood has the following structure:
- Nucleus - is formed as a result of the death of living cells. It is dark in color.
- Sapwood is the layer that carries nutrients and water from the roots to the leaves.
- Cambium is a thin layer made up of living cells. From it comes the annual increase in thickness of the tree.
- Bast layer - conducts organic substances produced in the leaves to the rootstree.
- Bark is the rough outer layer. It serves as protection against various mechanical damage and weather conditions.
What is sapwood?
Sapwood is the layer of wood that lies just below the bark of a tree. It carries water from the root system to the leaves. The sapwood is lighter in color than the inner part of the tree, called the core. It has less strength and resistance to fungal diseases and insects. It is known that:
- Some tree species, namely birch and aspen, are composed entirely of sapwood.
- In oak, the underbark is not used due to increased softness.
- The use of cherry sapling is determined visually.
Pine trees just below the bark contain a very valuable resin called resin, which, when extracted, exposes the surface of the sapwood. In addition, since ancient times, people have used this layer of some young trees for food.
Heartwood and sapwood
Young trees of any species do not contain a kernel, they consist entirely of sapwood. Only over time, this wood passes into the core as a result of blockage of the pathways through which water entered, resins, calcium carbonate and tannins. Therefore, the color of the core becomes darker. In different trees, the time interval for the formation of the nucleus depends on the growing conditions and the species. The transition from the subcortex to the core can be both smooth and abrupt.
Fancy food
Sapwood or sapwood is a young layer of wood. Its quite possibleuse for food. In the famine years, the inhabitants of Leningrad during the blockade ate the so-called "birch porridge", that is, birch sapwood, and the northern peoples - spruce. Various cooking methods:
- Pine, spruce are finely cut and boiled, while changing the water several times. This procedure is necessary to get rid of the resin. Then dried and added to milk, flour or eaten immediately.
- The birch is crushed, poured with water and wait until it swells. Then boil.
In addition, the sapwood of larch, linden, and aspen is eaten. It is known that Kamchatka hunters, leaving for fishing, took only salmon caviar from food. On the way, they cut birch sapwood and ate it instead of bread.
Underbark function for lumber
In a sawn tree, sapwood performs an insulating function, and in a live one, it is a conductor of water from the root system to the foliage, and also contributes to the laying of spare substances in the wood. Sapwood is removed during the manufacture of rounded logs, and for chopped lumber it is preserved, so they are more reliable and durable. They are not afraid:
- wind and frost;
- dampness and moisture;
- insects;
- temperature fluctuations;
- ultraviolet rays.
Due to the fact that sapwood is a woody layer with good absorbency, logs treated with an antiseptic are reliably protected. Such lumber is used to build houses in the traditional Russian style.
