Trees in winter
Published 9:08 am Tuesday, January 1, 2019
When the forest is laid bare each winter there is a tendency to think of it as a bleak and dreary place. But the basic structural skeleton of each tree can be seen at this time, with every branch, twig, and bud visible, thus revealing how it has grown in the past, and how it has prepared for the future. So put on a coat, go outside and go look at a tree.
Trees all have a trunk anchored to the ground. It has a skin of bark, which varies widely in appearance if you look closely. Beech is smooth, cedar is shreddy, and many have a series of ridges separated by furrows that form distinct patterns. There are many colors of bark as well, and with a good field guide you can identify trees by their bark alone.
Branching off the trunk are major limbs that eventually divide to form branches that in turn divide to form small branches and finally twigs. Standing back and looking at a winter tree silhouette reveals how the tree has grown in the past to maximize exposing its leaves to sunlight, which is the basic yet elegant purpose of growing in such a three-dimensional form. Sunlight is the name of the game. There are two main patterns you will want to notice. One is a single main trunk with limbs and branches radiating off it. The other has the trunk eventually splitting into smaller trunks that spread to form a wide canopy. The first form is conical and sort of pointed, like cedars, pines, and yellow poplar. The second form is more spreading and rounded, like oaks, elms, and sycamores. How large and spreading a tree canopy is depends on several things, but mostly on the amount of sunlight it receives. Open grown trees like in a field can spread in all directions and have large, wide canopies. Trees in a forest have to stretch themselves tall to stay even or above neighboring trees as they fight for position in the sun. They will have long, limb free trunks that finally form a much smaller canopy.
There’s one other thing to notice about a tree’s branching pattern. Some species have what is called opposite branching, meaning the smaller branches form on the larger branches in opposing pairs. This will be evident throughout the canopy, and even the buds. Maples, dogwood, buckeye, and ash all have opposite branching. The other pattern is called alternate branching, where the branches form randomly here and there, and this is found in oak, hickories, and many others.
Besides bark and branching patterns, one final feature to check out is the winter buds, the time capsules of next year’s growth. Inside each one is a miniaturized set of leaves that will provide next year’s food for life. Some are flower buds that will allow the formation of seeds to fulfill the great desire of all life forms… to have offspring and continue the species. Buy a small magnifying glass and look at the buds up close. They are amazingly complex and varied, each species having its own pattern of bud scales, shapes, and colors.
So take a winter walk in the woods and enlarge your world by looking closer at the trees.