Winter provides a special opportunity to experience trees.

Bark is the outer part of the tree that we see best on the tree’s trunk. Farther inside the tree, Sapwood is that part of the tree where rings form as the tree grows each year. Heartwood is the interior part of the tree, and is made of cells which allow water to move up and down.

Bark is the protective lining of the living tree. This ‘skin’ bears scars and wrinkles that testify to the trials of its life. Wounds scab over, leaving a lump, slash, or sometimes a knob. If disease gets into the wound, or insects move in, the tree could eventually die.

The bark of each tree is like a unique fingerprint, exclusive to that tree species only.
 
Today’s activity is tree fingerprints!

You’ll need: -paper (any kind will do, even grocery sacks!)
                  -crayons or colored markers
                  -a field guide to the trees of your area (for older children or adults)
                     or a guide to trees that includes details about their bark

Pre-activity: Scout the trees in your yard or a neighborhood park, looking for different tree species (which means different types of bark). As you find the trees, flag them so that you can find them again. 

Step 1: Point out the trees you have flagged.
Step 2: Give each person one or more crayons and a piece of paper.
Step 3: Ask them to make a rubbing of the tree bark by putting the paper aganst the bark then moving the crayon back and forth over an area of bark at least as big as their hand. Press hard so that a good impression of the grooves and bark scales is made.
Step 4: Send each person to a separate tree to make their bark rubbing. Remind them to press hard against the paper with the crayon.
Note: Be sure that the bark is not injured during the rubbing process, and above all, don’t peel the bark away! This injury could cause the tree to become diseased, or allow an insect entry into the more sensitive sapwood.

Step 5: In a group, have each person show their bark rubbing. Ask questions about the rubbings. Suggestions are:

How is the tree’s bark like our skin?
Do you see any scars or injuries in your bark rubbings?
How might this tree have been injured?
Does tree bark look different as a tree gets bigger/older?

Step 6: Can you identify the tree using the tree field guide?

Step 7: Finally, does the pattern of the bark remind you of any animal? Could it be the skin of a giraffe, a leopard, a zebra, a frog? Have fun creating pictures of animals using the bark pattern from your rubbing for their skin!

This activity was not taken from any particular activity book, although many books have great suggestions for activities about trees. Here’s one of my favorites:

The Tree Almanac, A Year-Round Activity Guide by Monica Russo. Sterling Publishing: New York, New York. 1993.