Trunk (botany)

The 15-meter circumference is the lower part of the thuja folded trunk ( Thuja plicata ). Vancouver Island Canada

The trunk is the main, axial, radially symmetric, vegetative organ of the plant, the stem of woody or tree-like (eg palm trees ) plants.

The tree trunk is characterized by a shape close to cylindrical, having some runaway - a gradual decrease in diameter to the top. A trunk with a strong run across the entire height is called runaway , only in the lower, butt part - stumpy . Also, the trunk has other drawbacks of shape and structure ^[1] .

The part of the tree trunk that remains after its cutting and includes its roots is called stump .

Content

Trunk Structure

The trunk consists of 5 layers: core, wood, cambium, bast and peel.

Core

Slice of a 27-year-old yew berry with a pronounced core

The central layer of the trunk, in which nutrients and, sometimes, moisture are often deposited.

Wood

Layers of cells through which an upward flow of water and minerals passes from root to crown. In species of trees growing in polar or temperate latitudes in the warm season , it grows faster, forming a lighter and thicker layer than in the cold. Such layers are called annual rings , thanks to them you can determine the age of the tree by its stump. In plants growing in the tropical zone , tree rings often do not form.

Cambius

A section of the trunk of the Tien Shan spruce that fell during a hurricane .

The layer of educational tissue of the tree trunk, in which the formation of bast and wood occurs.

Bast

A layer in which a downward flow of photosynthesis products (sugars) from the crown to the root occurs.

Crust

The outer dead layer of the cells of a tree trunk. often contains tarry substances . Over time, during the growth of the tree, the crust breaks and becomes coarser. Peel protects the barrel from getting wet and temperature changes .

Barrel Value

For a plant

The trunk serves to move the plant sap from the roots to the crown and vice versa. At the same time, it helps the plant to maintain an upright position. In tropical forests, the trunk holds the crown of the plant at a height that sunlight penetrates, making photosynthesis possible in its green parts.

In some plants, such as a bottle tree and baobab, the trunk is a "reservoir" for storing moisture and, therefore, indispensable for survival in dry places: deserts and semi-deserts .

For animals

In tree trunks, cavities are often formed that are convenient for arranging animal dwellings, such as squirrels and owls . Also, some insects, such as bark beetles live under the tree bark, feeding on wood .

For man

Wood is the main material for the manufacture of furniture, it is also used for the manufacture of other things, in particular homes and souvenirs . For this reason, the problem of deforestation is relevant ^[2] .

Under certain conditions, wood eventually becomes peat , coal, and finally anthracite , which are used as fuel . The wood itself was also used as fuel.

Petrified wood is used as an ornamental stone .

Notes

↑ Vakin A.T., Poluboyarinov O.I., Solovyov V.A. Vice of wood. - Second edition, revised and supplemented. - M .: Forest industry, 1980 .-- 197 p.
↑ RIA Novosti: Deforestation in the tropics accelerated rather than slowed, scientists say , RIA Novosti (15:51 02/26/2018).

Links

Tree (plant) - an article from the Great Soviet Encyclopedia .

[1] Vakin A.T., Poluboyarinov O.I., Solovyov V.A. Vice of wood. - Second edition, revised and supplemented. - M .: Forest industry, 1980 .-- 197 p.

[2] RIA Novosti: Deforestation in the tropics accelerated rather than slowed, scientists say , RIA Novosti (15:51 02/26/2018).