Watching a single tree over time can yield insights about nature. REBECCA REID
By DAVID SPECTOR Gazette Contributing Writer
A couple of decades ago, my camera and I went to a corn field near my home on Jan. 1. The field served as a setting for a gem of a maple tree that had been allowed to grow in the middle of the corn. On or near the first of each month for the rest of that year, I went to the same tree and took photographs documenting the changes in the tree and its surroundings. In October I also went mid-month, in an attempt to get an image of the tree at its most colorful.
More recently another tree caught my attention: a black birch across the front lawn from my home. A year and a half ago, in the first week of May, I noticed several thousand catkins, each bearing pollen-producing flowers, hanging from the outer twigs of the entire tree in an image of a bursting yellow fireworks display.
For the following year, and to a lesser extent since then, I wrote frequent descriptive notes about this black birch. I enjoyed watching the leaves, flowers and seeds change.
I counted 194 seeds in a cone in September and combined that with several fall estimates I made that averaged about 5,000 cones on the tree, calculating that this tree produced close to a million seeds in 2011. I watched the wind-assisted dispersal of those seeds and saw them fall prey to seed-eating birds. While the tree slowed its processes in the winter, I thought about its conservation of water and energy. In the spring of 2012 I got a surprise when the tree reminded me of the year-to-year variability of annual cycles by producing almost no flowers (and hence, no seeds this winter).
My efforts to track the changes of each of these trees, in one case just recording images and in the other taking detailed notes, gave me fun with phenology, the study of annual timing of natural events. It’s something almost anyone can do, a valuable exercise in the art and science of careful observation. You might start with trees.
Trees are convenient for such a study; an individual stays put and can be easily found throughout the year. It would be a challenge to follow a plant that spends much of its year as a seed or as an underground structure with little or nothing showing above the surface.
Identifying and following a mobile individual animal for a year would be even more demanding, but many species can be observed throughout the year even if individuals usually cannot be tracked. The choice of an animal species affects the kind of observations that can be made over a year. Here in western Massachusetts most insects, amphibians and reptiles are inactive and difficult to find for much of the year.
Small mammals are usually difficult to observe, and following migratory birds south to the tropics or north to the Arctic would be fun but not practical for most of us. Some large mammals and resident bird species do allow year-round watching, and in a few cases distinctively marked individuals of such species even allow repeated observation of the same animal.
There is no need to follow any particular calendar. January 1 is one day to start a year of observation, but any other start date would do (e.g., Tet, Rosh Hashanah, your own birthday, the vernal equinox, Groundhog Day, etc.). I started watching the black birch when its floral display caught my attention. Similarly, the first of the month is a convenient reminder to look, but any monthly date can serve (e.g., the Ides of a month, the date of the full moon, the day the rent or mortgage is due, etc.).
I invite readers to try this exercise: Choose a tree or an animal species and follow it for a year. Take notes and/or photographs on a regular basis, think about the events and challenges in another species’ life, and become more familiar with a non-human organism’s annual experience. You might well find the effort rewarding enough to continue it with the same or another species.
David Spector is a former board president of the Hitchcock Center for the Environment and teaches biology at Central Connecticut State University.
Earth Matters, written by staff and associates of the Hitchcock Center for the Environment at 525 South Pleasant St., Amherst, appears every other week. For more information, call 413-256-6006, or write to us.