Getting out into the woods, yard or even nearby vacant lot is one of the best means of gaining an understanding of natural processes-a key discipline in the sciences. Charlotte Mason, a British educational reformer, saw the study of nature as the means of training the senses to absorb the all-important details and then to draw conclusions.
A fascinating area of nature to study is the microclimate. A microclimate refers to the climate of a small unit of nature (e.g. a bit of land, a plant, or a habitat) which is different from the total climate around it. For example, often the band of land on the south side of a building provides a warmer climate to grow certain kinds of plants when compared to the north.
Example of a microclimate
Insects that have a three-stage life, such as a butterfly, make their own microclimate. A good subject for study is the goldenrod gall wasp. In spring the mother wasp plants an egg in the stem of the goldenrod plant. She also injects a chemical which stimulates the growth of thousands of extra cells that surround the newly-laid insect egg--forming a gall, a large, round, hard swelling in the plant. When the insect egg hatches inside the gall, a small white grub called a larva emerges.
The gall does not harm the plant. Children can think of it as a home which provides food and shelter for the growing grub. The grub will remain in his house all summer and through the following winter. The next spring the grub will change (metamorphose) into an adult wasp. The newly-winged insect chews a small round tunnel in the side of the gall to exit and fly off to mate and start the process over again.
Five microclimates to study
Here are five microclimates to look for on your next nature walk as recommended in Ten-Minute Field Trips, (National Science Teacher's Association, 2001):
Look for galls on stems of goldenrod or other wildflower, also oak trees, willows, roses and blackberries. Note: If you want to open a gall, use double-edged hand-pruners. These cut into galls safely without cutting the animal inside, or small fingers.
Find an anthill in a crack in the pavement. The hill is made of sand and soil. Why do the ants prefer the side walk? Asking why should produce a good discussion.
Watch for spittle bugs which excrete a liquid and beat it into froth. The froth is found on the stems of most wildflowers (meadow spittle bugs in spring, summer and fall or on pine trees. How is the "spittle" creating a microclimate? What purpose does the spittle serve?
A stump or dead logs are small ecosystems which create their own microclimate. Many insects feed on the decaying wood. The moist interior can be home to slugs, while the moss and lichen grow on the cooler north and west sides (usually).
Microclimates occur in rocky outcroppings. Are plants growing in the crevices? If you lift a rock does the temperature change on the underside. Are there different plants and insects there?
Resources to study microclimates
Field guides are excellent to bring along for identification. For greater training of the sense use a nature journal to list or draw all the elements of the microclimate and for further study back home. To get in-depth information on individual species of the microclimate use Handbook of Nature Study by Anna Botsford Comstock, an outstanding compendium of information on all aspects of nature in North America and available from Living Books Curriculum.
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