|
 |
|
|
|
 |
 |
Home l Community l Education |
|
|
|
|
|
| |
|
|
|
|
Timber is wood cut
from trees and used for building and to make products
such as furniture and paper. People all over the world
use timber products every day.
Timber is an amazing natural products. It can be used
in many different ways to produce a variety of products.
One timber product can be re-used to make another. Most
timber products are biodegradable and when trees are
harvested for timber, new trees can be planted to take
their place.
|
 |
Trees
Timber is produced from the wood of trees
grown in forests. A forest is much more than
a group of trees used for producing wood and
a habitat for animals and plants. It also
is an ecosystem where the soil, water, temperature,
plants, animals and micro-organisms interact
(work together) to maintain balanced life
cycles.
Trees play an important part in the forest
habitat and ecosystem and are homes for forest
animals and plants. The leaves of trees help
to clean the air by absorbing carbon dioxide
from the atmosphere and releasing oxygen back
into the air.
Tree roots grow into the soil to make trees
stable and to collect water and nutrients.
The network of tree roots holds the soil together
and protects the soil from being washed or
blown away by rain and wind.
If soil and plant litter are not washed into
rivers and streams, our waterways stay clean
and unpolluted. Even though there are lots
of different types of trees, all trees have
roots, a trunk, branches and leaves. |
|
 |
Roots
A tree¡¯s roots usually grow below the surface
of the soil and act as an anchor to hold the
tree in place. Without deep roots a tall tree
would fall over. Roots absorb water and nutrients
from the soil through tiny root hairs. The
water and nutrients flow through the roots
into the trunk, branches and leaves to feed
the tree. |
|
|
Trunk
The trunk is the main stem of the tree.
Most of timber comes from the trunk
of trees. The outside of a tree trunk
is covered in protective bark. The outer
layer of bark is made up of dead cells.
The inside layer of bark contains living
cells called phloem (flow-em) that transport
carbohydrates from the leaves to other
parts of the tree. As new phloem cells
are produced, the old cells die and
move out to become part of the outer
layer of bark. Under both layers of
bark is the wood which botanists call
xylem (zie-lem). Xylem is made up mostly
of dead cells with an outer ring of
living xylem cells. Water and dissolved
nutrients flow through the living cells
from the roots to the branches and leaves.
In between the phloem and the xylem
is a thin layer of cambium (cam-bee-um)
cells where new xylem and phloem cells
are made. |
|
|
|
Growth rings
Inside the trunk of many trees, each year¡¯s
production of xylem cells forms a visible
ring, called a growth ring. Because a growth
ring represents one year¡¯s growth, it is possible
to discover a tree¡¯s age by counting the rings.
The colour and thickness of the rings are
affected by the season. Spring growth by a
tree produces a lighter coloured ring than
growth in summer. |
|
|
Branches and
leaves
Branches are smaller woody stems which grow
from the trunk and produce the leaves. Many
important processes take place in the leaves
of trees: photosynthesis (foto-sin-the-sis),
which makes food for the tree: respiration,
which converts the food into energy for the
tree; and transpiration, which keeps the tree
cool. |
|
|
|
|
|
| |
|
|
