WOOD MATERIALS TECHNOLOGY

4th Edition

Chapter 7Wood: What is it?

Trees release lots of oxygen into the atmosphere and they take in (absorb) Carbon dioxide.

In effect they clean the air for us.

Tropical rainforests are known as carbon sinks

They release:– oxygen

They absorb: – carbon dioxide

Some benefits of trees

− A renewable source of fuel− Woodland walks− A habitat for wildlife− Fruit, nuts, oils and other products− Raw material for paper and cardboard− Wood/timber from which many things are made

Are there different types of forest?

− Natural forest, such as tropical rainforest or natural woodland

− Planted forests− Coniferous forests

− Wood pellets− Bark mulch

− Oriented strand board (OSB)

− Fencing

What are new ways of using wood and waste timber effectively?

− Forest management (afforestation)

− Log harvesting− Tree care− Nurseries− Christmas tree farms

− Carpentry− Transportation− Fuel production− Arts and crafts

List jobs in forest and timber based industries

The story of a Tree:

Planting•Firstly, land is drained to allow the rain to drain away freely. Trees are then planted here and fences are put up to keep out animals that could cause damage.

Thinning:

Trees are thinned when about fifteen years old to allow more space and light for the growing trees. The thinnings are recycled.

Harvesting:

Harvesting happens when the tree is about fifteen to thirty years old.This is where all the tree’s in an area are cut down, this is known as clear felling:

Transport and Processing:

•Tree is transported to a sawmill to be processed.•Logs are then cut into planks where they are then left to dry for use in furniture making, construction or making manufactured boards.

DeforestationDeforestation is the destruction of large

forests areas without replanting trees cut down

Timber is a renewable resource only when it is managed properly and trees replanted when cut down

In tropical regions forests are been cut down and not replanted.

It is estimated areas the size of Ireland are being lost each year.

Reasons for Deforestation (x4)Large areas cleared for farming and

ranching (slash and burn technique)High demand for tropical hardwoodNatives of some regions use timber as an

economical source of fuel for heating and cooking.

Commercial interests of large multi-national and local logging companies

Cattle raising and commercial farming.

Effects of DeforestationSlash and burning methods kill all animals, birds

and insects causing many to become extinctBurning of trees contributes to air pollutionNumber of trees available to consume CO2 and

produce O2 is reduced, causing the greenhouse effect

Effects the weather and global climateIncreases soil erosion in deforested areasNative tribes are removed from their homesFlooding – as trees consume large amounts of

water their removal can cause the water table to rise

How to Prevent DeforestationOnly use tropical woods that are

grown in managed forests (for each tree cut down one is replanted)

Where possible use manufactured boards rather than solid tropical hardwoods

Try to recycle wood and wood products – paper

Use veneer instead of real wood.

Forestry in IrelandCenturies ago much of ireland was

covered in forestry but much of it was cut down to make things such as houses, barrels and boats.

The largest areas of natural forest cover are in Wicklow and Kerry with others all around the country.

Now many plantations exist around the country, these mostly being softwood, such as sitka sruce and lodgepole pine.

Irish forestryIreland is one of the least forested countries

in the EU however Irish forest no’s are rising all the time due to government incentive to plant.

Early in the 21rst century ireland had a 1% forest cover, this is now at 10%.

Coillte are the company that manage the countries forestry.

The Government have also invested huge sums into the development of forestry.

The Greenhouse effect.

Air pollutants like carbon dioxide build up.

They form a blanket effect around the earth.

Heat from the sea prevented from leaving.

Temperature slowly rises.