Why are Trees Important?

checklist

Targets

At the end of this Unit you should be able to answer the following questions 

1. Why are  trees important?

1.1 Why do trees and forests have value?

1.2 In what ways do plants and animals live on, under, and among trees?

1.3 What role do trees have in nutrient cycles?

1.4 How do humans use trees as natural resources?

Forests cover 1/3 of the Earth's surface. There are an estimated 3 trillion trees on Earth. They exist in almost every climate on Earth: hot, wet, dry, or cold. However, there are three main types of forest zones. These are named after the distance of the forest from the equator. Forests are tropical (close to the equator), temperate (warm), or boreal (far away from the equator). Do you recall in what zone most Canadian forests are located?

For more information on the forest zones, visit this website.

  Video

Watch the Tropical Rainforest BrainPop video.

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Pixabay

The tropical rainforest is a diverse ecosystem that is home to most of the world's species.  Hundreds of tree species are the anchor of this forest, and millions of species wait to be discovered.

Many natural medicines have been discovered in rainforests.  That is reason enough to consider the tropical forests very important, but that is not all.  Hundreds of the tree species have fruits that can be eaten, and the vast stretches of rainforest in tropics have a large role in removing carbon dioxide from the air, which is important for keeping global temperatures stable.

Temperate forests grow in areas with four seasons within a range of -30°C to +30°C. Decaying fallen leaves and moderate temperatures combine to create fertile soil.

To learn more about Canada's temperate forest, watch the Canadian National Film Board video The Temperate Rainforest.
Or, watch the video
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A great resource, our boreal forest, covers a vast amount of our country, more than 60% of Canada's land mass in every province and territory and 58% of Northern Alberta. Boreal or taiga forests grow in cold areas. The areas are usually snowy and range in temperature between -40°C to +20°C. The ground is usually made of a very thin layer of nutrient-poor, acidic soil

To learn more about Canada's boreal forest, watch the video
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  Math Connection

The size of forests is often measured in hectares.  (If your family uses acres to measure land, you might need to think of a hectare as approximately 2.5 acres.)  A hectare is 10 000 square metres, which is about the size of 40 tennis courts.  Boreal forest covers about 574 million hectares, which is about one-quarter of all the forested area on Earth.


  Environmental Connection

There is so much to learn when studying trees.  Trees are of many kinds, trees are used for thousands of things, and many wonderful, interesting facts and figures concern trees.

For a small taste of the amazing world of trees, try a little "Tree Q&A"!

Tree Q & A

A: If you guessed trees, you are correct! In California, there is a bristlecone pine tree nicknamed "Methuselah" (muh-thoo-zuh-luh) that is more than 4760 years old.


A: Trees! Parts of trees are used in many common products. Mouthwash, paint, and bubble gum contain elements of trees.

A: Danger! Danger! Willow trees can "talk" to each other by letting out a chemical when they are attacked by webworms and caterpillars. Other willow trees close by detect this and then put more tannin into their leaves. The tannin protects the trees by making it difficult for the webworms and caterpillars to digest the willow leaves.

A: A white cedar tree that grows in Canada on a cliff in the Great Lakes area