On this early spring day a gentle breeze blows barren branches to and fro. Each limb sways to the rhythm of the wind and from this vantage point they appear to be sweeping the sky. The movement of these branches is somehow dream-like, and puts me in a pensive mood. I am surrounded by forest and feel as if I am shrouded by wonder.
These trees. So many. So select. They hover over the moist humus forest floor casting thin shadows on ground that still is thawing. Within my eye shot these woods are diverse. To the north, down a slope, there is a wolf tree. It is an old sugar maple. Its branches start low on the trunk and spread horizontally. The outline of the tree has a dome-like form as sugar maples often do. The long lower branches indicate it once grew in an open pasture; free from competition and able to send branches out rather than up. There was no need to compete for light in this, long since gone, open field. This maple enjoyed open sunlight throughout the entire growing season for decades.
But things change. With the agricultural decline at the end of the 19th century humans stopped using this hillside for pasture. Sheep and cows were moved to greener areas or not raised at all. This land waited not for more human incursions. The fields changed from grasses to goldenrods, asters, and blackberries. This old field plant community then evolved to shrubs and saplings. Shade from the new overhanging branches weeded out many of the forbs and herbs. A forest began to grow. The trees were close together. They grew straight and tall during the short growing season competing for solar energy. Now most of these woods hold large trees; oak, sugar maple, yellow birch, white ash, red maple, and black birch. It is a diverse mix of trees that reflects the old forest found not too far away where steep rocky slopes were never logged because they were too difficult to navigate.
There is some sort of irony here. We humans tend to think of trees as being stationary. We think of them as growing in one spot, photosynthesizing, soaking up carbon, and providing habitat for the mobile vertebrates that inhabit these woods. A different form of life we think; these trees, these plants that are immobile and seek no adventure beyond their own shadows. And yet this very location, devoid of all topsoil, all plants, and all animals due to ice scouring after the last glacial period period is now lush with forest life! The trees and plants found here had to travel, on their own accord or perhaps with a little help, hundreds and hundreds of miles from landscapes that were not impacted by the thick sheets of ice that retreated to the north nearly twenty thousand years ago. The trees accomplished this movement by reproduction and casting seeds into the future; a seemingly reckless and random method of traveling.
We vertebrates can move great distances as individuals but live relatively short periods. Trees move by generations and live long lives. Wind blows pollen from one tree to the flowers on another tree, or bees and other insects carry the pollen and leave it behind on a flower in waiting. Each tree produces a different type of fruit or seed carrying vessel. Members of the maple family drop winged seeds that rotate unevenly as they fall toward the ground. The uneven rotation tends to make the seeds travel further and wind will make long distance travel much more likely. Oaks drop acorns. These nuts are utilized by dozens of vertebrates for food, but one in particular, the blue jay, carries the acorns long distances to hide it from competitors. Not all of these acorns are recovered by the jay. Some sprout and grow into seedlings far away from the parent tree. And other trees like the black cherry produce a true fruit that is consumed by turkeys, bear, deer, fox, and coyote. The seeds survive the vertebrate digestive track due to their hard covering and are moved about in droppings good distances from where they were consumed.
The new seeds must sprout, root into the soil and grow into a new tree. The odds are slim that an individual seed will survive but thousands are planted about in hopes that some will make it through predation, severe weather, and other disturbances. Even as seedlings there is a good chance that they will be trampled, stricken by drought, or consumed by an herbivore such as a white tailed deer. Only a few seedlings grow to saplings and only a few of those grow into trees. The tree must grow to maturity before it can produce its own seeds and start the forward movement once again; such a slow and precarious method of moving about. For some tree species it can take generations to move a mile. For others tens of miles can be accomplished in the same amount of time. By vertebrate standards this method of getting around makes molasses in January look like the space shuttle Endeavor.
To put this method of travel in perspective, it took the black spruce something like 18,000 years to travel from the northern Smoky Mountains (which was suitable for this species but remained free from glaciation) to the northern Canada where this conifer dominates the landscape today. This is a distance of about 2500 miles. Certainly this was a very, very slow pace that took place over hundreds of tree generations. Slow and steady wins the race?
Still, in geologic time, this is a rapid and recent development. The earth is something like four and a half billion years old. If the history of the earth were mapped on a 24 hour clock, the time it took the black spruce to travel from nonglaciated areas to their present location would take place in about a quarter of a second. The relativity of time is astounding to the casual observer. It is cause for long and careful thought.
The natural world we live in is intricately woven into fine cloth that has discernible patterns if we take the time to sort them out. At first glance the patterns appear to be wild beyond imagination, but with a sharp eye we soon can see that these patterns are a map of where we came from and where we may be going. Perhaps it is time to study these natural patterns to determine our best course for the future. Now is not the time to be lost.