Which Trees Change First?

September is really still summer, right up until the autumn equinox on September 22, when the day and the night will each be 12 hours long. But September begins to feel like fall as days get shorter and cooler.

Just like people, the trees in September begin to get ready for the coming winter. The trees which will spend the winter without their leaves, called deciduous trees, will soon begin turning color. It can be fun to do a study of which trees begin to change color first. Here are a few ideas to help you get started.

Some trees which are not healthy change color before their neighbors. Look at any tree which is already changing to red, yellow or brown before the other trees and try to see if it has some kind of problem. Does it have a large wound in its bark? Is it close to a street where car exhaust or winter road salt might be a problem? Is it a newly planted tree which no one watered this summer? Find out more about what causes health problems for trees.

Keep a notebook or chart on what kinds of trees change color when. Write down the date and the name of the tree whenever you see a tree which has a lot of leaves changing color. Decide how much of the tree's leaves have changed, a third, a half, etc. before you enter it in the notebook or chart.

Use books, pamphlets, grown-ups, Web sites etc. to identify the kinds of trees you are observing. Do trees which are originally from North America (like Sugar Maples and White Ashes) change color before or after trees which are originally from other parts of the world (like Norway Maples and Weeping Willows)? Why do you think there might be a difference?

Save colored tree leaves by pressing them between the pages of a big book or ironing them between two pieces of wax paper. Get help before trying to use an iron. Do leaf rubbings by putting a piece of paper on top of a leaf and then rubbing a crayon across the paper. You can even make photocopies of leaves.

Do trees near water (lakes, rivers, ponds) turn color sooner, later, or at the same time as trees not growing near water?

Find a school or student in another part of the state or country and compare leaf color notes this fall.

Look at leaves from some trees that keep their leaves all year such as pine trees. How are they different from the leaves of trees that lose their leaves in the fall? See if you can think of why some trees can keep their leaves all year and others cannot. Do some research and try to find out what scientists think about this. Betsey Maestro's Why Do Leaves Change Color? published by HarperCollins is a picture book written for 4 to 8 year olds on this topic.

Visit Yahoo's page of links on Fall Foliage.
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