Branching Out With Technology
by Bob Coulter
As the articles in this issue show, an in-depth study of trees can be the basis of many interesting investigations in your school-yard and in the surrounding community. Opportunities for hands-on, authentic learning are almost endless as students study trees, their leaves, and the animals that call the trees home. As a teacher, I found the many changes trees undergo throughout the year to be particularly interesting areas for discovery.
As you and your students engage in these investigations, be aware of the many possibilities you have to integrate technology resources into your study. No use of computers or other high-tech equipment should be allowed to substitute for your students? first hand experience, but carefully considered use of technology can extend both the depth and breadth of your students? study of trees. The three projects described here can get you started.
How are our leaves different?
A study of trees should start with field work in your local community before you venture online. When students have a strong grasp of basic concepts such as size, shape, texture, and coloration as they relate to local trees, they can look outward to other regions much more effectively. To do this, you and your students can use online resources such as those compiled by the Missouri Botanical Garden and the Evergreen Project to compare and contrast the tree leaves found in your community with the leaves in other parts of the world. The Biomes of the World website assembled for the "What?s it Like Where You Live?" curriculum units is designed to help students make these comparisons, drawing out key concepts such as how the temperature and rainfall in an area help to determine what plants and animals can live there. Look for this resource at: http://mbgnet.mobot.org/sets/index.htm
Through these investigations, students should become used to thinking about basic questions such as "How are our leaves similar? How are they different?" as well as more sophisticated questions such as "What adaptations do leaves from our community have which help them survive in our local climate?" By doing so, students improve their ability to see more deeply, an essential component of doing good science at any age.
Moreover, these comparisons help students extend their understanding of essential aspects of tree leaves beyond what was achieved in your local field work. Questions such as "How are desert plants different from plants in the rainforest?" or, "How do plants in the taiga or tundra compare to our plants?" help to place the observations made of local plants in a much broader context, enhancing students? analytic powers.
Finally, as your tree study moves forward, students can use these comparisons of the local and the distant to develop broader ecology concepts such as adaptations and biomes (ecologically distinct regions) much more effectively than would be possible if your study were limited to the local community. From the first study of a leaf on your school grounds to a global comparison enhanced by internet resources, a careful look at leaves can promote a great deal of learning.
What happens as seasons change?
If you are in a region where trees shed their leaves in the fall, try to photograph the changes in the leaves. By selecting a particular leaf or branch to observe and record closely, you can create an impressive record of seasonal change. For instance, as part of an autumn tree study, photographing the same maple leaf every day or two will capture its changing color as temperatures fall and days get shorter. One day, you will be in a position to photograph the leaf-less branch, a sure sign that winter is coming.
In the spring, you can work with your students to document exactly the opposite process as the buds emerge and a new leaf grows. Again, the regular photographs will help to document this seasonal change. When the new leaves emerge, record the date. If it has been an unusually warm (or cold) spring, how do your students think the weather may have affected the timing of the leaf?s emergence? Keeping an ongoing record of these phenomena from year to year will provide a database which will intrigue future students.
If your school is fortunate enough to have a digital camera (or if one can be borrowed for the project), your students can import the pictures into a Hyper Studio or Power Point presentation and create a "flip-book" of how leaves change in your community. Students can add text and other diagrams to document their understanding of how leaves reveal seasonal change. Background information on this can be found at the "What?s It Like Where You Live?" website described above. On a more basic level, even ordinary snapshots displayed sequentially on a bulletin board will make an impressive and eye-catching display.
If you have been observing tree leaves emerging in the spring, your students can extend their study by participating in "Leaf-Out," a project run by Journey North (http://www.learner.org/jnorth/) which spans North America (with a few European schools as well!) For this project, leaf-out is defined as when the leaves of one of four trees reach the size of a quarter. The four species (sugar maple, flowering dogwood, eastern redbud, and quaking aspen) are selected to ensure that nearly every community has at least one species to track. Range maps can be found in almost any tree field guide, or online at the Journey North web site. (Follow the links from the home page to the Leaf-Out project).
By tracking and reporting to Journey North when leaf-out happens in your community, your data will be joined with those from other participating schools across the continent. The map shows data from the spring 2000 reporting season. Notice that leaf-out typically occurred earlier at southern schools, with spring unfolding across North America as the season progresses. Students should be alert to anomalies, however. Notice that the school in West Virginia reported its leaf-out later than other schools at the same latitude. What factors unique to that area might cause this to happen? Is the climate different there? Why?
Your students can develop their geography skills in the process of studying trees as they retrieve the data from the Journey North database (by following links from the "Report Your Data" section of Journey North) and plot new locations each week on a map of North America.
While you're at it, explore the many other signs of season change tracked by schools participating in Journey North. Trees can be just the beginning of many fascinating investigations of the natural world!
- Bob Coulter is director of Mapping the Environment, a program at the Missouri Botanical Garden's Litzsinger Road Ecology Center that supports teachers' efforts to enhance their science curriculum through the use of the Internet and geographic information system (GIS) software. Previously, Bob taught elementary grades for 12 years.