Looking through the magnifying glass we can see wood's macrostructure and through the microscope we see its microstructure. Timber structure is seen differently in transversal, tangential and radial sample section. The cross-section is perpendicular to the axis of the trunk, tangential is a ling trunk axis and radiate - along through the center of the trunk.
The most important parts of timber macrostructure are core, kernel, lath and bark. They are seeing the best in transverse cross-section of maturing. The core is in the center of the trunk, but sometimes it can be shifted to one or another side and is 2-5 centimeters diameter, so it takes only a very small part of the trunk. A lot of trees have an oval core but some of them has a special form. Alder has a triangular, ash quadrangular, poplar has pentagonal and the oak's is a star shape. Core with a little wood layer which has formed in the first growing year is called a core tube. Its timber is fluffy, with weak material and less adult with other timber layers.
A lot of different types of wood are light and in the cross-section have the same colour. Other tree species cross-section has different colour - central part is darker and the outer side is lighter. In this case darker central part of the trunk is called the kernel and the lighter one lath. The splinter is younger than a part of the trunk, its wood is not so adult, not enough dence because of this is less valuable. There are always growing new lath layers under the bark. Some part of dying inter layers increases the weight of the wood. Some trees lath colour does not separate from the kernel. In this case wood closer to the center is less wet so because of this it is called mature. Those tree species which have a clearly visible kernel are called nuclear and those with the same colour and wet in all plot of wood section are called alburnum. This kind of wood is birch, alder, linden and maple.
Most wood matures spruce, beech and aspen. Some of the trees have apparent (unreal) kernel, its central part of the trunk is just a little bit darker. Oftenly, it is the first sign of wood deterioration, obvious timber defect.
Bark protects the tree from all the harmful external effects and mechanical damage. The outer cork layer of bark these functions performs the best. The internal bark layer is called a blast. The juice is flowing in it when the tree is growing. Looking into transversal of a just cut tree through the magnifying glass it is seen that between peel and alburnum have a live cell ring, called the cambium. In tree's growing time there are new cells producing in the cambium, because of this a tree plumps. The cambium is not seen in a cut tree, it disappears.
In normally grew tree cross-section is bright concentric timber layers. Each such a ring shows an annual timber increment and it is called an annual ring. Conifers annual rings are seen very well. In a radial cross-section it looks like longitudinal stripes and in a tangential like conical lines. The weight of annual rings and every year growing wood content determines tree age, space and growing condition. Younger tree rings are wider. Wood with narrower tree rings is more resistant.
To grow a good quality tree takes a lot of time. There are many more features which describe different tree species. Wishing to build something from wood for example a wooden garage, firstly it is recommended to inquire advantages and disadvantages of different trees and then to choose a right one. You have not to forget that the middle age tree would suit the best for constructions, they will be strong and durable.
