Right now as I drive around the Vineyard, I suddenly feel disoriented and for a moment not sure where I am. I experience this unexpected disorientation despite my having belonged to Dukes County Search and Rescue, the U.S. Army, and still a Boy Scout. Sure, I am aging. However, all appears okay with me. Much of what was a familiar landscape appears to be different from what I am accustomed to. After some reflection, I realize that it is the environment around me that has changed. Some leaves have dropped and, in some cases, leaves changed color. Fall approaches and the changing and shrinking foliage reveals what had been hidden from me all summer. Suddenly I see houses, barns, stone walls, and other landmarks that had been hidden by summer shrubbery. To research what has caused my observable environment to change, I turned on my computer and Googled “When leaves fall.”

The firs phenomenon I come across is that leaves do not really fall. Therefore, it seems to me that saying that fall is coming is really a misnomer. According to Dr. Peter H. Raven, emeritus president of the Missouri Botanical Garden, leaves do not fall from tree branches, the leaves are thrown or cut off. Since we live in the northern hemisphere and the temporal zone, as the days grow colder and shorter a hormone is triggered in deciduous trees. The leaves begin to change color and appear to get crunchy and dry. As part of the process, where the branch and leaf stem meet, little cells, called abscission cells, appear. Since these abscission cells have the same root as the word scissors, like scissors, they are programmed to cut.

Therefore, slowly, daily and weekly, all the leaves develop more cells that start and continue a process of pushing the leaf away from the stem. Naturally, the connection between a leaf’s stem and the branch becomes more and more tenuous with time. Because of this continual weakening of the connection between the leaf stem and its branch as well as the added weight of the leaf, a strong breeze or rain can complete the process of the leaf’s being pushed off and slowly gliding to the ground. Gravity must help the process, too. Of course, Irene’s rain and wind a few weeks ago hastened the process of pushing leaves off. Interestingly, though, as we Vineyarders can observe, oak leaves are an exception and hang on.

After reading about what is going on with the shrubs and trees all around me as fall arrives, I feel more comfortable about the cause of my present disorientation while driving around the Vineyard. Now, if you are a student attending one of our Martha’s Vineyard Schools or an off-Island school and want to learn more about what is going on within the shrubs, the trees, and why leaves change color, you may want to speak with either your teacher, your school science teacher, your school librarian or librarian in any of our town libraries. For those of you who have a computer at home, you can do the research at home by going to Google or any number of platforms similar to Google. Indeed, I would love to hear what you find out, so please e-mail me at the Edgartown Library (hfoster@edgartownlibrary.org) with your research results. As an incentive for completing your research, we will post some of the responses on our Edgartown Library Web page.

Herbert Foster is an Edgartown library trustee and a member of the Statewide Advisory Committee on Libraries.