Unlocking the Secrets of the Pinecone
Depending on where you live, this time of year the ground might be covered in snow, ice, and most importantly – pinecones! We see pinecones everywhere during the winter, in wreaths, on trees, and in our yards, but did you know that pinecones have a vital job – they keep pine tree seeds safe, and protect them from the freezing temperatures during the winter!
To protect their precious seeds, pinecones can close their ‘scales’ tightly, keeping out cold temperatures, winds, ice, and even animals that might eat the seeds.
In this activity we will observe how pinecones respond to different temperatures, by mimicking changes in weather, all from the safety of our own kitchens! As an added bonus, after this activity your pinecones will be ready to be added to your house as a holiday decoration, or as a beautiful reminder of the plants of the season!
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Did you know that pinecones can stay on pine trees for over ten years before falling to the ground?! During that time, seeds for new pine trees grow under the scales of the pinecones. The scales protect the seeds from bad weather, and from animals that might eat them. However, eventually the seeds need to be released so that they can grow into new pine trees. To make sure that the seeds have the best chance of finding fertile soil and growing into trees, the pinecone scales stay tightly closed when the weather is inhospitable to new seed growth, i.e. when it’s very cold and damp outside. In contrast, when the weather is hot and dry, the seeds will have an easier time finding good soil and growing into trees. In these conditions, the pinecone scales will open, allowing seeds to escape and drift away, to find new ground to grow into new trees!
As you will observe today, after pinecones fall from the tree, they can still open and close. In this activity, we will test the conditions that cause pinecones to open and close, all from the warmth of our own home!
*For all measurements in this activity, use centimeters (cm)
Extra: After taking them out of the oven, try putting the pinecones back into the cold water. Remove them after several minutes and measure their length and circumference again. How does cold water affect the size and shape of the pinecones?
Extra: Try lowering the temperature of the oven to 150 degrees, and testing the effect on the size and shape of the pinecone. Do the pinecones get larger than they did in the 250 degree oven, or smaller? Why do you think this happens?
Extra: After taking the pinecones out of the oven and measuring, put them in the freezer overnight. When you take them out in the morning, measure the length and circumference again, and compare them to the final measurements. Did the pinecones get larger or smaller? What other changes do you observe?
Observations and Results
In the activity you observed and recorded the affect of different temperature and conditions on the size and appearance of pinecones. In the first part of the activity, you may have noticed that placing pinecone A in the cold water caused the circumference of the pinecone to decrease. This is the expected result. In response to cold and damp conditions, pinecone scales close tightly, making a natural shell to protect the precious seeds inside.
After taking pinecone A and B out of the oven, you measured all of the pinecones to get their final measurements. When you compared the final measurement of pinecone A to the cold water measurements, you should have observed that the circumference of pinecone A increased after being in the hot oven. In addition, when you compared the final measurements to the initial measurements for all the pinecones, you may have noticed that the circumference of pinecones A and B both increased. In each case, the increase in the circumference of the pinecones results from the scales of the pinecones opening up in response to the warmth of the oven. The pinecones think it’s a warm summer day, and are ready to release their seeds!
More to Explore
Megan Arnett, PhD, Science Buddies
Science Buddies |
Outdoor science, plant science, temperature, recording data, analyzing data
Explore Our Science Videos
Make a Homemade Fly Trap
Is the Egg Raw or Cooked? STEM activity
Make a Thermometer - STEM Activity