Wooden” and “Heartwood” redirect here. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, wood router basics pdf wood chips or fiber. 5 billion cubic meters of wood were harvested.
Dominant uses were for furniture and building construction. Buildings like the European Neolithic long house were made primarily of wood. Recent use of wood has been enhanced by the addition of steel and bronze into construction. Where the differences between the four seasons are distinct e. Where there is little seasonal difference growth rings are likely to be indistinct or absent.
If the bark of the tree has been removed in a particular area, the rings will likely be deformed as the plant overgrows the scar. If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or springwood. The outer portion formed later in the season is then known as the latewood or summerwood. As a tree grows, lower branches often die, and their bases may become overgrown and enclosed by subsequent layers of trunk wood, forming a type of imperfection known as a knot.
The dead branch may not be attached to the trunk wood except at its base, and can drop out after the tree has been sawn into boards. 90 degrees different from the grain direction of the regular wood. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow. Knots materially affect cracking and warping, ease in working, and cleavability of timber. They are defects which weaken timber and lower its value for structural purposes where strength is an important consideration.