tcj_materials

include component="page" page="toolbar_TCJ" editable="1" include component="page" page="toolbar_tcj2O" editable="1" MATERIALS

A tree has 3 major parts: a. roots - (the roots are the parts that grow in the ground) b. trunk - (the trunk grows above the ground) c. crown - (the crown grows out of the trunk, upwards and outwards) = The Roots = The growth of the tree depends on the minerals, nitrogen and the water it gathers from the ground. The layer the crown grows on top so must the roots. The roots help anchor the tree to the ground. The roots also store food over the winter to help start tree growth in the spring. = The Trunk = The trunk is the body of the tree that supports the crown and provides channels, which carries sap and food between the roots and the crown. There are three main layers to tree: a) Outside thin layer called bark b) Solid wooden parts in the center called wood c) Between the wood and the bark is a living layer called cambium = Bark = The bark of most are made up of two layers. The inner layer is soft is and moist, this part transports food from the leaves to the roots and other parts of the tree. That is why, when the bark of a tree is cut all the way around the trunk down to the wood, the tree will die ‑ the roots will starve to death. The outside layer of the bark is dead and it protects the trunk from weather, disease and decay. = Wood = The wood makes the trunk of the tree strong so it can support the crown, it also has the job of carrying water and nutrients from the soil up to the leaves to be made into food. The wood is divided into a light‑colored layer called sapwood, which carries sap from the roots up through the trunk of the leaves and a dark‑colored layer called heartwood, which is a dead core that simply gives strength to the tree. = Cambium = Cambium is a thin (one cell) layer between the wood and the bark, which has the job of building a new layer of bark each year. It is difficult to see the bark layers, but the wood layers are usually very clear. Wood formed in the spring is light colored, while summer‑wood is much darker. If a tree is cut down you can count the dark rings (called annual rings) and learn how old the tree is. = The Crown = The crown of a tree is made up of the limbs, twigs, leaves, buds, flowers and fruits. Limbs or boughs of a large tree was once a branch, and before that a twig that grew from a bud. On hardwood trees the buds are formed during the summer at the base of the leaves. The buds remain when the leaves fall in the autumn, and the following spring they burst and send out new shoots at an angle from the branches. this process goes on year after year. On conifers trees the formation of buds is different. Pine buds form only at the tip of the twigs. In spruce and fir they form at the tip of the twigs and also back on the new shoots. Branches carry the leaves outward and upward into the sunlight where they can manufacture food. Branches also bring sap (water and dissolved minerals) to the leaves from the trunk of the tree and carry food back to the different parts of the tree.
 * TREES**
 * Parts of a Tree**

= TREE IDENTIFICATION = There are two main groups ‑ the conifers, commonly softwood; and the deciduous trees, commonly referred to as hardwood or broad ‑ leaved trees.

1. Have needles which usually remain on the tree all year except tamarack 2. Have cones. 3. Wood is generally soft. 4. Wood is generally not strong 5. Often grow in cold climates. 6. Usually grows rapidly
 * CONIFERS** (softwood)

1. Have broad leaves which they lose in the fall. 2. Have no cones but may have fruit. 3. Wood is generally hard. 4. Wood is generally strong. 5. Often grow in warm climates 6. Usually grows slower.
 * DECIDUOUS** (hardwood)

Because wood is a natural material taken from plants, it has some very definite limitations.

1. It is subject to decay and destruction by insects. 2. It is flammable. 3. It shrinks and swells with the changes in moisture content of the air surrounding it, often warping as a result. 4. Wood is not equally strong in all directions.


 * Softwood** types: cedar, fir, hemlock, pine, redwood, spruce, tamarack.


 * Hardwood** types: alder, balsa, basswood, birch, cherry, elm, hickory, mahogany, maple, oak, popular, rosewood, teak, walnut, willow, zebrawood.