You've already been examining how trees are intricately tied to human life, but there's so much more to know. Take plenty of time to appreciate trees, but make sure you study different types so you aren't missing the forest for the trees!

The Secrets of the Rainforest

What makes a forest a rainforest? Tropical rainforests receive between 160 and 400 inches of rain each year. How much rain does your locale get each year? All of that rain makes rainforests chock-full of life and nutrients. Rainforests are so full of plants and trees that they play a very large part in controlling the climate of the Earth. People also rely on the rainforests for certain foods and medicines. Unfortunately, rainforests are being cut down at an alarming rate to make room for farms or to get at oil underneath them.

Unlike other types of forests, rainforests cannot be replanted or replaced. This is because the relationship between the plants, animals, and insects that rely on one another is diverse and complicated. It is an interconnected system that has been evolving for almost 100 million years. Once it has been cut down, it is gone forever.

Almost every minute of every day another acre of rainforest is cut down. Help protect the rainforests by joining the Kids for Saving Earth Forest Protection Plan. This plan is protecting and adding to an existing national park in Costa Rica. Visit www.kidsforsavingearth.org/programs/rainforest.htm to start learning about this amazing forest and how you can help protect it.

Kirigami Tree

Trees come in all sorts of beautiful shapes and sizes. Look through books with pictures of trees and discuss the basic shapes of trees. Some are triangular, like evergreens, and some are more like lollipops, with trunks and circular tops. What other shapes are there?

Kirigami is like origami, but you can cut the paper instead of only folding it. Give each student two pieces of construction paper and have them lay one on top of the other. They should sketch a basic shape — just the outline, no details — onto the paper. Then, they fold them down the middle the long way (still, one on top of the other). Cut along the outline on one side of the fold. Like cutting snowflakes, it will cut through all four layers of paper. Open the pieces and use tape or glue to connect the two pieces of paper along the folds. When they are connected, you should be able to open them up and square them so that the four halves are perpendicular and each tree is able to stand on its own. From here, have the students cut more detailed branches into the basic shape to make the trees really come to life.

Adopt a Tree

Have you ever really watched a tree? In many climates it's obvious when buds form in the spring or when leaves change color and drop from the limbs in the fall, but what about all of the other subtle changes? In this activity, your class will adopt a tree to study and report on for the whole school year. They'll see how trees grow and change, just like people. Here are the basic steps:

• Have the class select a tree, preferably a nice specimen in your schoolyard so it's easy to watch.

• Keep a camera handy to take a photograph each week and make a poster that has the name of the species and any other pertinent information (location, approximate age, size, etc.). You can even have the class vote on a pet name for the tree if you'd like to personalize it.

• Attach a few sheets of paper to the poster where students can write down weekly observations about how the tree changes.

What happens to the tree? Can you see signs of growth? Do the leaves change? Does it grow any flowers, fruits, berries, seed pods, or nuts? What kinds of animals or birds frequent it? Does it ever look affected by climate (like when it's very dry or very cold)?

After many months, your students should have a much better understanding of and respect for trees. As an end-of-the-year celebration, have a picnic in the shade of your tree and say goodbye to it for the summer.