Forest and Human Succession

My morning stroll around the nature trail behind my house revealed a pleasing present and hints of the history that lead to what I could see in the woods today. Walking the trail just after sunrise, the woods were alive with the sound of bird calls: friendly chickadees, social gold finches, and the coy red-eyed vireo. The chickadee paid me no attention at all – it flitted from branch to branch on an alder bush near the trail, intent only on breakfast. The gold finches were chattering to each other high in the treetops, discussing perhaps the merits of choosing this old field as a source of seeds. The red eyed vireo sang in its clear, strong whistle, “here I am… where are you? Here I am… where are you?” I didn’t answer, as I suspect it is a rhetorical question. Blue jays called in their raucus voices from south of the field, intent on keeping the world safe from hawks and owls.
Every species of bird, plant, and animal seeks a niche in the environment best suited to its habits. The red eyed vireo needs reasonably deep woods to shade its understory nest, hanging under a slender branch between the forest floor and canopy. The chickadees need the old aspen trees with their numerous woodpecker holes for a place to nest. The gold finches need the open field and its profusion of plants to provide seeds to fuel their incessant conversations.
Each species singing in the early morning sunlight shares this place because it meets its needs for food and shelter. Why here? Why now?
It is the recent human history that has most shaped the landscape that sustains the particular birds this August morning. After the logging era, many of the loggers bought the recently cleared land for farming. An old fence line running along the bank of the creek attests to the use of the field for grazing cattle. The Baldwin apple trees out near the big road suggest a small orchard. The fence kept the cattle from the creek, and its banks are now embraced by large oak, maple, and white pine trees. I wrap my arms around the trunk of an oak, and my arms are each a foot or so too short for my hands to meet on the other side. This is an old oak.
Like many of the first farms, the sandy soil could not support a family. The farmer and his cattle abandoned the field, and nature has begun to return it to forest. But a forest is only the last stage of a continuing cycle of plant communities. The fence line that protected the trees became the leading edge of the forest community. Sun loving trees, the elms, cherry, and poplar, began spreading south into the pasture. Bracken fern, now a chest high swath of deep green, race into the opening for the sunlight. Under the shade of these pioneer species, more shade tolerant species sprout and grow – the white pine and maples in particular. The aspen continue to colonize the sunny edge of the field, always 20 years ahead of the maples. But a generation behind them, the first aspen and elm trees are in decline. These tall, massive big tooth aspen trees, 50 to 60 years old, have lost thier vigor, and their rotting core is home to fungi and insects – hence the woodpecker holes and resident chickadees. As the aspen die and fall, the white pine and maple saplings stand ready to recieve the sunlight that built the first generation of forest trees. It is under these 20 foot maples the red eyed vireo weaves it’s nest. The middle of the field, still the realm of mullein, goldenrod, grasses and thislte, provide the banquet for the finches.
I never greeted the neighboring farmer. But by his toil nearly a hundred years ago, and the natural succession of plants into his field, his successors greeted me in the early morning sunlight, content in a present shaped over the course of a century.

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