Groundhog's Day had hardly passed last year when the wave of spring reached Texas. "I just saw my first redbud leaves here in Houston,"reported Jo Leland on February 7. "We are on the Gulf Coast so spring comes earlier for us!" And the green wave moved on. The season's first leaves were reported from Virginia on February 13, North Carolina on March 2, Pennsylvania on April 24 and Ontario on the 16th of May. By the time the leaves emerged in Alaska it was the end of May.
Again this spring, students will choose a local tree and learn its name. They'll send news to Journey North when its leaves are the size of a quarter, our definition of "leaf-out." To expand the study, students can investigate the relationship between leaf-out and temperature as explained in the "Spring Fever" lesson on page 111. They can measure this locally and can link with other classrooms to compare results. Students will be introduced to the wealth of information about climate on the Internet and investigate how it relates to leaf-out across the continent. A host of activities are planned in hopes that students will ask questions about such things as: How do trees know it's spring? What happens if the leaves come out too early? How do the leaves in my backyard fit into the food chain? Is it true that some songbirds arrive from the Tropics just as the leaves emerge on my trees? Perhaps there's a student who will take the lead and track North America's leaves full course, until they fall back to the Earth next autumn.
© Journey North 1996