A Matter of Degrees: Understanding Microclimates

Testing Whether Temperatures in Your Garden Accurately Reflect the Temperatures of Your Region.

As we prepare to use the blooming of tulips to track spring's progress, certain expectations probably come to mind. Most likely, we expect to watch a gradual wave move northward as gardens report blooming flowers, one by one. What factors might get in the way of our expectations? What assumptions have we made in designing this experiment?

In this lesson students will learn to recognize the variables that can create a microclimate. Then they will measure one of the variables, temperature.

Activity
1. As an introduction to this activity, have students review the planting instructions. Make a list of all the variables we are attempting to control.

2. Define and discuss the word, "microclimate".
A microclimate is the climate of a small, localized area in which the climate differs from the general climate due to the unique amounts of sunlight, wind and moisture this localized area receives.

Microclimates can occur in localized areas due to nearby:

• Man-made features (buildings, parking lots, roads),
• Geographical features (mountains, oceans, lakes) and
• Biological features (forests, prairies, croplands).

3. What is the microclimate of your garden?
Take students outdoors to look for conditions that create a microclimate. For example, measure the temperature, note the length of time your garden receives sunlight & shade, note the proximity to a building, investigate the moisture conditions, the exposure to wind, the porosity of the soil, etc. Can you find more than one microclimate on your school grounds?

4. Measure temperatures in your garden.
As discussed in the "Growing Degree Day" lesson , temperature is believed to influence the rate at which tulips grow. Therefore, in order for the Journey North study to be valid, temperatures in each garden need to accurately reflect temperatures of the region.

When we pick up the newspaper we're told the temperature of our city. However, people in the same city will notice very different temperatures depending on their location. (For example, it can be 20 degrees warmer beside a sunny parking lot than under a shade tree on a north-facing slope.)

Do temperatures in your garden accurately reflect the temperatures in your region?

Print out the temperature chart .

Record daily the daily high and low temperatures that are published in your newspaper on the chart. Periodically, go outside and measure the high and low temperatures in your garden. Compare these temperatures to those reported in your local paper.

• Are temperatures in your garden generally warmer or cooler than the temperatures reported in the newspaper?
• If different, by how many degrees do they vary? Why do you think this is true?

6. As a class, discuss whether you think your tulips in your garden will bloom "at the right time" for your region.

Note: If you don't conduct this lesson now, keep it on hand. In the event that northern gardens bloom before their neighbors to the south, student interest may lead naturally to this investigation.