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Branching Out

Identify some trees without leaves.

While there is something missing from many trees this time of year (namely their leaves!), you can still tell one tree from another by looking for other clues.

Trees have very distinctive silhouettes (with and without their leaves). Many guide books include tiny silhouettes to help you identify the trees, Trees come in all shapes and sizes, just like people! The bark also differs considerably from tree to tree, and from young to old. Again, like people the bark of younger trees is smooth and even; older trees have rough and wrinkly looking bark.

Buds offer many clues, too. Before trees even lose their leaves in autumn, they are preparing for the new leaves that will clothe them the following spring. Each bud is protected by a scaled covering, or fuzzy hairs. There is much variation from tree to tree.

Some trees are easy to identify any time of year. These are the evergreens that keep their leaves year-round (see below).

Take a look at some evergreens.

Do the evergreens really keep their foliage year-round? Well, yes and no. They do shed their leaves (as the needles are properly called), but it is an ongoing process, making the loss less noticeable.

Not all evergreen trees are conifers (cone-bearing trees such as pines, firs and hemlocks). Holly trees, live oaks, and palms are three exceptions, being broad-leafed examples of evergreens, On the other hand, some needle-leafed trees, such as larches, are deciduous and lose all their leaves each autumn.

You can tell the three major groups of conifers apart by their leaves. Here are some clues to took for.

Firs Short needles with blunt tips, leave round scar on branch		Spruces Four-sided needles that are very sharp		Pines Needles grow in bunches, wrapped together at the base

See how important trees are in nature.

You can probably think of dozens of uses for trees, but did you ever wonder what role trees play in nature? Take a walk outside and see if you can detect some of the ways trees serve the natural world.

You can't really see, but you might guess at one way that trees are important, and that is their ability to hold the soil together with their far-reaching roots. These "underground branches" prevent erosion, but they also provide safe havens for burrowing animals. Animals live in other parts of trees, too. Look for holes in trunks that squirrels and birds have made. On dead limbs, lift the back and look for the squiggly tunnels and pinholes made by various insects. Leaves also provide shelter (check this during the summer).

Of course, trees furnish food for many animals. Not only are nuts and fruits eaten, but also twigs, bark, and leaves. The leaves serve other functions, as well. They give off oxygen and transpire great amounts of water. And when the leaves fall from the trees, they decompose and enrich the soil, as does the tree itself when it dies and rots, but not before still other creatures find food and shelter in the tree. Little wonder trees are so valuable in the wild.

Name some of the ways people use trees.

Besides benefiting from trees in their natural settings, people use trees in many ways. Look around your house, or in your neighborhood stores, for examples of tree products. You can even make a game of guessing what objects in your house started out as part of a tree,

You'll probably find many examples. Your house may be made from wood (at least in part) as well as some of your furniture, tools, and toys. Paper, and such products as fabric, photographic film and cellophane are made from cellulose (the major component of the cell walls). Food is harvested from trees (from apples to almonds) including spices and flavorings (from cinnamon to maple syrup). Gums and resins (special saps that ooze from certain trees) are used to manufacture paint thinner, soaps, and rubber goods. Some bark is used for floats and bulletin boards.

So thank a tree the next time you make a paper airplane or crack open some pistachios! Come summer, you'll be glad for the shade that trees offer, too.

Make rubbings of tree bark.

You can record variations in bark patterns by making rubbings. All you, need is a sheet of lightweight paper and a wax crayon (dark colors show up best), Peel the paper-covering off the crayon and hold it horizontally. Smooth barks are easiest to rub, and steady one-directional strokes work best. If the paper keeps shifting, tie it to the tree.

You can bind your rubbings in a scrapbook, or frame them to hang on the wall. Include rubbings in the diary you are keeping of a single tree.

Note: Never strip bark from trees, as that may damage or even kill a tree. You can collect bark off of fallen branches and stumps.

Count the rings on a tree stump.

Trees grow not only in height each year, but also in girth, and you can actually count the years that have passed by counting the rings on the stump of a tree. The rings also offer clues to the conditions that affected the tree during its lifetime. Wide rings show years of strong growth; narrow rings suggest that the tree was subjected to adverse conditions, such as drought, a hard winter, insect damage, rite, and even competition for sunlight and nutrients from neighboring trees.

Unfortunately, to see the rings of a tree the tree must be felled. Search your area for stumps, or take a look at a fireplace log. This activity is suggested again on December 29, when it is possible to determine the age of your's or a neighbor's Christmas tree.

The oldest trees in the world are in the United States. Some of the bristlecone pines, found in the Southwest, are over 4,000 years old,

Guess the age of a living tree.

By measuring the girth of a tree (about five feet from the ground), you can guess the age of a living tree. Most trees will measure about one inch for every year of growth.

This method works only for mature trees and there are notable exceptions. Most poplars grow too fast, and some (such as the Scotch pine and horse chestnut) grow too slowly to make this method reliable all the time. A tree growing by itself might conform to this rule, too, whereas a tree the same size growing deep in the woods might be twice as old. Having competed for moisture and sunlight its whole life, its growth will have been stunted.

Count the number of rows of branches radiating from the central trunk of a pine (such as the white pine). Each row represents one year's growth.

Scout for trees to date, on your property or in a park or wooded area near you. Can you find any of the same types of trees growing in both open spaces and densely wooded spots? How do they compare in size, and how old do you suppose they might be? What important historical events were taking place when those trees were just seedlings?

From The Kids' Nature Book, by Susan Milord.
Available from Williamson Publishing Company
(800) 234-8791. Reprinted with permission.