Are trees made of wood

Wood as a raw material

What is wood

Wood is a renewable raw material, one of the most widely used plant products in the world - and one of the most stable substances in the plant kingdom. Because of its strength, trees can soar more than 50 meters into the sky. Wood consists of tubular cellulose cells that are glued together by a solid, colorless hydrocarbon compound - lignin.

The lignin is stored in the cell wall and serves there as a strengthening element. When plant cells lignify, one speaks of lignification.

Depending on the tree species, the cells are of different sizes and structures. This results in the different characteristics of the wood, such as weight, density or strength.

Botanically, a distinction is made between hardwoods (angiosperms) and conifers (gymnosperms). As a rule, hardwoods are heavier and harder than the conifers.

layer by layer

If you saw a tree trunk, several layers can be seen: From the inside out, they are heartwood, sapwood, cambium and bark (bark).

Each of these layers has a specific function. The heartwood inside the tree trunk consists of dead wood cells. Because resins and tannins are embedded, it is particularly strong and resistant.

Living tubular wood cells form the sapwood and surround the heartwood. They store nutrients and direct water into the treetop.

The cambium is responsible for new wood cells. It consists of a few layers of cells that can divide. On the inside they give off wood cells for the water transport, on the outside sieve cells for the juice transport, which takes place under the bark.

The bark itself is made up of dead cells and protects the tree from extreme temperatures and from animals.

In spring the cambium forms new cells and the tree becomes thicker. It then stops cell growth in late autumn.

The cells that have emerged since spring are larger than the previous ones, so that the typical annual rings come about. The age of a tree can be precisely counted on them.

Sustainable forest management

Wood is one of the most widely traded raw materials in the world. Trees are constantly growing back, but depending on the type of wood, growth takes a long time.

In many regions of the world, the renewable raw material is not handled carefully, which means that too much wood is felled too quickly.

The German forest, on the other hand, is managed sustainably. The concept of sustainability stipulates that a new tree should be planted for each felled tree. As a result, wood stocks cannot shrink so quickly because wood keeps growing back.

Things look worse in Brazil or Malaysia, for example, because the tropical forests in particular are threatened by overexploitation. The tropical rainforests as the "lungs of the earth" as large oxygen producers are vital for humans.

To counteract the overexploitation of the forests, the "Forest Stewardship Council", or FSC for short, was founded in 1993. The organization has set global standards for environmentally friendly and socially responsible forestry.

A seal of approval from the FSC signals to the consumer that the wood products come from sustainable forest use.

Positive ecological balance

Wood is an extremely environmentally friendly material. The use, burning or biodegradation of wood does not cause any further increase in carbon dioxide in the atmosphere and thus makes a valuable contribution to climate protection.

When burned, for example, only as much carbon dioxide is given off as the tree has stored in the course of its life. Young forest trees then take up this carbon dioxide again.

If wood from local areas is also used, the transport costs are quite low due to the short travel distances.

Another advantage for the environment is that wood hardly creates any waste: by-products such as sawdust, sawdust and wood chips can be used for the production of paper, chipboard and fiberboard or for modern heating systems.

If a wood product has had its day, it can be converted back into heat or electricity in an environmentally friendly way.

Versatile in use

Furniture is perhaps the best-known everyday object in this country that is made from wood.

But wood can be used a lot more: entire houses can be built from the material. Almost everyone knows Sweden's red and white wooden houses from Astrid Lindgren's stories.

This type of construction is characteristic of all of Scandinavia. And in the USA, too, a large number of houses are built from wood. In rural areas, the proportion of wooden houses is well over 90 percent. In Germany, on the other hand, only just over ten percent of houses are built from wood.

There are no limits to the use of wood as a building material. Even bridges and huge halls can be built from the raw material, which was proven in 2000 by the self-supporting EXPO roof of the German pavilion made of silver firs.

Heating with wood

Anyone who has ever sat by a tiled stove with a crackling fire knows how pleasant this warmth is.

In fact, heating with wood is an environmentally friendly alternative to fossil fuels. While natural gas and mineral oil release fossil carbon dioxide (CO2), wood burns in a CO2-neutral manner.

Modern heating systems that are fed with wood pellets or leftovers from sawmills reduce the greenhouse effect in the atmosphere.

Anyone who has dared the relatively high costs of installing such a heater not only saves a lot of money in view of the rising energy prices for oil or gas, but also makes an important contribution to climate protection.