Hooked on Science: Pine cone hygrometer

Materials

• Pine cone

Instructions

• STEP 1: Attach a pine cone to a secure location outside.
• STEP 2: Record the humidity for your location from weather.gov and whether the pine cone is open or closed each day. Represent your data in a table.
• STEP 3: After two weeks, graph your data. What happens to the pine cone when the humidity is high? What happens to the pine cone when the humidity is low? Describe any weather patterns over the two weeks. Using the data, describe the typical weather conditions expected during this time of the year.

Explanation

Pine cones act as a natural hygrometer, which measures the amount of moisture in the atmosphere. Pine cones contain seeds, which are transported by the wind. Pine cones open their scales to disperse the seeds when the air is dry and close their scales when the air is moist, which keeps the seeds dry. Therefore, when a pine cone closes its scales, it's indicating a higher humidity, while a pine cone with open scales indicates a lower humidity.