Summary: Students observe changes in a selected tree bud/leaf near their home during the spring. Twice each week students record changes in the bud/leaf using words, pictures, and numbers. Observations continue for a period of three or more weeks. Activities in the classroom will emphasize the connection between plants and various cycles (carbon, water, nitrogen). The Family Page extends this learning to the community by inviting parents to facilitate home observations and discussion related to seasonal plant adaptations. Note: This inquiry will require a minimal classroom time commitment and will therefore be implemented in the midst of other classroom science activities.

• Chlorophyll. Chlorophyll absorbs sunlight using the sun's energy to make food for the plant. In preparation for freezing weather, nutrients move slowly out of the leaves and into the tree's branches, trunk and roots where they are safely stored against the cold. When spring comes, the tree draws on these nutrients to grow new leaves.
• Water.  Deciduous trees (those with broad, flat leaves) lose their leaves in the fall to save water in order to survive the upcoming winter. Trees as well as all other plants take in moisture through their roots and lose moisture through their leaves. This process, called transpiration, contributes a significant amount of moisture to the air. This moisture then evaporates upward and continues its journey through the water cycle.  During the warmer months transpiration is what keeps leaves moist and healthy so they can produce sap (food) for the tree using the sun's energy. 
• Sunlight.  Trees as well as other plants use the energy of the sun to make a kind of sugar in their leaves that is the tree's food.  This process is called photosynthesis.  Since the first day of winter, daylight hours have been growing longer.  Daylight hours will continue to lengthen until the first day of spring.  More hours of daylight means more hours for plants to make food.
• Temperature.  As spring approaches, weather conditions begin to fluctuate.  Warmer temperatures combined with increases in sunlight and available moisture signal trees and other plants to begin a new season of growth.
• Adaptation. 
  • An adaptation is a body structure or behavior that allows a species to survive over time. A hummingbird beak is an example of a body structure adaptation because it is long and thin and adapted for retrieving nectar from flowers. Bird migration to find food, on the other hand, would be an example of a behavioral adaptation.
  • In the spring deciduous trees adapt to seasonal changes in water, sunlight, and temperature by sprouting leaves. During the late spring and summer months, deciduous trees make all of the food they will need for the entire year.  Changes in sunlight, and temperature in the late summer and fall lessen a tree's ability to make food.  Trees adapt to these seasonal changes by shedding their leaves.  While this prevents a tree from continuing to make food for growth, it also greatly reduces the amount of water lost through transpiration.   Trees in effect go through a period of hibernation in the late fall and winter by transferring the sap made during the warmer months down into the roots of the tree and using it sparingly during the winter months. The structural adaptation of sprouting and shedding leaves throughout the year allows a tree to perform the behavioral adaptation of migration.
• Observation vs Inference. Observations are what you learn by seeing, smelling, touching, tasting, and hearing. Inferences are conclusions that are drawn based on observations. In this activity students will observe the sprouting of a bud to a leaf using the senses of sight and touch. Their observations combined with classroom discussion should allow them to infer that changes in sunlight, temperature, and moisture in the spring signal deciduous trees to sprout their leaves.
• Misconception(s).  The entire leaf is packed into the bud. Fact: The tree manufactures new leaves in the spring using the sap (stored energy) from the previous year's growth.
• Caution(s). Students should choose a tree leaf that can be observed while standing on the ground. The use of chairs or ladders to observe leaves is not recommended.
• Expected Results.  Deciduous trees in Ohio will sprout most of their leaves between the middle of April and the middle of May.