Wood is the hard substrate that compromises most trees, bushes and shrubs.
It consists of:
Cellulose is a natural fiber with the following structure
These cellulose fibers bond to gather to form sheets which are held together with lignin forming the substance we know as wood.
Wood Cellulose is formed by the vascular cambium in trees and grows from the centre outwards forming characteristic growth rings
How Wood Forms and How Trees Grow
A tree consists of the following 6 parts
- The bark: The bark is the protective outer layer round a tree. It protects the tree from damage from insects,microbes and the environment.
- The phloem: The phloem is the living part of a tree that moves the sugar rich sap of the tree from the leaves to the roots.
- The cambium: The cambium is the active growing part of the tree, these thin layer of cells produce phloem cells on there one side and sapwood on the other.
- Sapwood: Sapwood is living cells of wood that are responisble for movement of fluids and sap from the tree roots to the tree leaves
- The heartwood: The heartwood is composed of dead cells. The heartwoods function is one of structural strengh and support
- The pith: The pith is the inner central core of the tree. It has a acts as a storage area for the tree storing micro-nutrients.
The wood we use for construction and furniture is composed out of Sapwood, Heartwood and the Pith.
The Cambium produces more woody tissue in early summer than late summer causing growth rings this can be seen in the above picture.