It doesn’t seem possible, but a few tree buds are beginning to swell, and some tree-watchers are eagerly anticipating the first unfurling green leaf.
After the last leaf drops at the end of autumn, the freshly naked trees may seem rather forlorn — cold, bare sticks in the rain. A closer look reveals much, however: identity, history, and community.
Although it might take a bit of study, most deciduous trees can be identified by their characteristic bark, twigs, buds, and limbs. Depending on the species, bark can be smooth, scaly, furrowed, peeling, or shredded, all in a wide spectrum of color. (Cherry trees, for example, have thin, striped-around bark.)
Trees also differ in the color, shape, texture, robustness, pointy-ness, and armed/unarmed structure of the twigs. (In case you’ve wondered, red alders are called “red” because of the color of the twig bark.)
Buds of the coming year’s leaves and flowers differ as well; in addition to varying by size, shape, and color according to species, buds of some trees are covered by one or several protective scales (such as willow or alder), others are naked (such as cascara). Even the scars left on the twigs by last year’s leaves vary in size and shape among species.
Limbs, too, can help identify a tree species, with forms ranging from a relatively few, heavy limbs that sag, to many slender whips that shoot straight up. As with leaves, the branches and twigs of some species are arranged in opposite pairs (maple, for example), though the parts of more tree species are arranged alternatively. The angles at which the branches arise from limbs, and the twigs arise from branches, are characteristic, too.
The dramatic architecture of branches and twigs are forms of fractals, patterns that repeat on a descending scale. The trees’ genetic information directs where and how to branch, of course, with variations on how often to branch, how many branches to make at each opportunity, what angle to branch, and such. (To see how very small changes in directions can lead to big differences in resulting patterns, play on the interactive website, http://mwskirpan.com/FractalTree/ .)
Bark and limbs also journal the life of a tree, history that can be read with a little observation and deciphering. Major events, such as fire, parasites or disease, storm damage or sawn removal, may be evident only in leafless winter.
The nests of birds, squirrels, and wood rats may be revealed this time of year, too, as may holes drilled or excavated by woodpeckers. And herbs, small shrubs, or infant trees that have sprouted in crotches and moss beds of the larger trees come into ready view.
The complex communities that are usually veiled by the trees’ leaves can also be more observable in winter. Now’s the best time of year to enjoy our astonishing variety of lichens flocking the bared branches and limbs and twigs. A lichen is the result of a relationship between one or two species of fungi and a photosynthetic organism, usually one-celled green algae or cyanobacteria (“blue-green algae”). The extraordinary relationship between fungi and partner makes them self-sufficient: they do not harm the tree.
The hazy mats of lichens and the bright, thick cushions of moss provide cover, insulation, and food for insects and other small animals. Birds — some of which may have nested in the same trees when they were in leaf — now can more easily be seen feeding in these 3-D communities.
While I certainly enjoy the brightening green of spring, I know that season will come in due time. Meanwhile, I’m happily enjoying the leafless trees!
Become a friend of Wavecrest Discoveries on Facebook! For information on how you can arrange an exploration of our fascinating natural history, contact Marty at 541-267-4027, or e-mail email@example.com. Questions and comments about local natural history are welcome.