12. July 2007
Vital nutrients are fed to the young plant through the core. Once other layers assume this role, it dries out and the pith forms.
Cell division occurs in the cambium. Wood cells form on the inside of the trunk and bast cells form outwardly.
During springtime, at the beginning of the growing season, wood cells with large cavities and thin walls are formed that are ideal for transporting water. This layer is called early wood and forms the light-coloured part.
In summer and autumn, cells become more thick-walled with smaller cavities, since they serve mainly for strengthening.
These cells are thicker and absorb more light than thin-walled cells, therefore, they appear darker. They are called late wood and form the annual ring. The structure of the wood is evident from a multitude of annual rings. The type of wood and the location define to what level they are pronounced. In native trees, they form annually with incremental growth. Woods from different growth seasons (e.g. tropical woods) show uniform cell patterns due to climate conditions.
The youngest and outer wood in the cross-section of a tree is called sapwood; its thin capillary transport water and nutrients from the roots to the crown. It is the water conduit of the tree, so to speak. In the bast, nutrients from the leaves are fed from the crown into the roots. It lives for a relatively short period and eventually converts to bark that protects the vital bast layer. The bark continually replenishes itself and forms the outer layer of a tree. Pit or wood rays are storage cells running across the direction of growth. They transport the sugar via the bast from the crown into the sapwood.
The heartwood is formed from inner wood layers after about 20 to 40 years, once the trunk has sufficient cell layers (annual rings) for nutrient and water supply. The tree stores tannins, resins, fats and often different pigments in the cells and closes the connection between them, so that they can no longer exchange substances between themselves. This kills the cells. The heartwood is the supporting layer of the tree. It is drier, more resistant, partially harder and heavier, and also usually darker than the rest of the wood.
The tree - a masterpiece, even in terms of its construction
Trees adapt their shape to evenly distribute loads along the entire surface. The tree continues to evenly distribute tension throughout its entire existence; it adapts its growth to outside conditions and forms thicker annual rings at the point of maximum impact. Thus, the tree is protected against storms and snow.
The construction of its inside is equally astonishing. Just think about the heavy loads of wind that are absorbed through the leaves and branches to be transported to the trunk, where thin roots feed it into terra firma at a safe distance. A wonder that is currently explored by biophysics researchers. Consequently, a number of design principles for modern building technology were developed.
Nicole Schemerl-Streben
The wonder of wood – the structure of wood
Despite the gamut of shapes and hues, wood is always made of the same substance. Biological processes are mostly identical too – yet: each tree is unique. Like every human being, each tree is an individual and an original.Wood is made up of cellulose and lignin. Furthermore, it contains resins, wax, fats, oils, starch, sugar, various minerals, tannins, pigments and alkaloids.
The diversity of wood is a product of its diverse structures, formed by nature. Wood has a very complex anatomy. It consists of specialised cells and cell structures that are responsible for storage, absorption of nutrients, growth and strength, respectively.
Vital nutrients are fed to the young plant through the core. Once other layers assume this role, it dries out and the pith forms.
Cell division occurs in the cambium. Wood cells form on the inside of the trunk and bast cells form outwardly.
During springtime, at the beginning of the growing season, wood cells with large cavities and thin walls are formed that are ideal for transporting water. This layer is called early wood and forms the light-coloured part.
In summer and autumn, cells become more thick-walled with smaller cavities, since they serve mainly for strengthening.
These cells are thicker and absorb more light than thin-walled cells, therefore, they appear darker. They are called late wood and form the annual ring. The structure of the wood is evident from a multitude of annual rings. The type of wood and the location define to what level they are pronounced. In native trees, they form annually with incremental growth. Woods from different growth seasons (e.g. tropical woods) show uniform cell patterns due to climate conditions.
The youngest and outer wood in the cross-section of a tree is called sapwood; its thin capillary transport water and nutrients from the roots to the crown. It is the water conduit of the tree, so to speak. In the bast, nutrients from the leaves are fed from the crown into the roots. It lives for a relatively short period and eventually converts to bark that protects the vital bast layer. The bark continually replenishes itself and forms the outer layer of a tree. Pit or wood rays are storage cells running across the direction of growth. They transport the sugar via the bast from the crown into the sapwood.
The heartwood is formed from inner wood layers after about 20 to 40 years, once the trunk has sufficient cell layers (annual rings) for nutrient and water supply. The tree stores tannins, resins, fats and often different pigments in the cells and closes the connection between them, so that they can no longer exchange substances between themselves. This kills the cells. The heartwood is the supporting layer of the tree. It is drier, more resistant, partially harder and heavier, and also usually darker than the rest of the wood.
The tree - a masterpiece, even in terms of its construction
Trees adapt their shape to evenly distribute loads along the entire surface. The tree continues to evenly distribute tension throughout its entire existence; it adapts its growth to outside conditions and forms thicker annual rings at the point of maximum impact. Thus, the tree is protected against storms and snow.
The construction of its inside is equally astonishing. Just think about the heavy loads of wind that are absorbed through the leaves and branches to be transported to the trunk, where thin roots feed it into terra firma at a safe distance. A wonder that is currently explored by biophysics researchers. Consequently, a number of design principles for modern building technology were developed.
Nicole Schemerl-Streben
