In our last column we climbed up to the top of Overlook Mountain on the Blue Trail — that’s the trail that takes you south from Plattekill Clove to Overlook Mountain. A century, or so, ago this site had been the victim of enormous environmental degradation. If you go up there and look carefully you may actually be appalled by how bad things must have become as the result of unbridled bluestone quarrying activities. There were few, if any, regulations back then. Nor were there many of the widespread environmental sensibilities that we know today. If all this destruction was going on today, many of you would likely be standing in the middle of Woodstock waving placards and screaming in protest.
But it is all over now, and there is nothing that any of us can do about it. Still, on a number of occasions when the two of us have wandered about up there, we have not been appalled; we have actually enjoyed exploring the site and seeing what is there. How come? Well, Nature has had about a century to recover from the damage. That is the subject of this week’s column.
If you know your way around the science of ecology, even a little bit, then you have heard of ecological succession. Clear a site, remove all of its plants and animals, expose the bare ground, and then wait. Over the course of years and then decades, an orderly and usually quite predictable sequence of plants and animals will return to that devastated site. Each step, along the way, is called a sere. Eventually a rich and diverse ecosystem will result. That’s the final sere; it’s called the mature climax community. Ecologists usually focus on the plants as they better define the sequence of succession. This is Ecology 101 stuff; it is basic, and it can be seen up there in the old Overlook quarries.
We begin by imagining what those Overlook quarries looked like on the day and the hour when the very last quarryman packed up and left the site, never to return. It must have been pretty bleak. Broken rocks lay strewn about in heaps all over. Quarried cliffs rose up above those heaps. Plants and animals were nearly absent. It could not have been a pretty sight.
Today there are the remains of that primitive sere. There is a rock strewn slope that expands out beneath the old quarries. It’s actually a picturesque place; it has an unimpeded view of the Hudson Valley in the near distance. Rising up through the rocks and boulders, are oaks and beaches. They seem to be adapted to this primitive state. Some of those oaks have diameter of 15 inches; they are getting old. All around the quarries are other, what are called, pioneer plants. Those are lichens, as thick and large as you will ever see. They are typical of the earliest sere.
This seems to speak of the slow re-establishment of a maturing forest ecology. Despite the devastation, a forest is attempting to re-establish itself right here. Throughout most of the quarries this process has been coming along more or less successfully. Today there is a “forest” of not terribly large trees throughout the site. They are not all that old, because they cannot be all that old; after all, their base environment began less than a century ago.
These trees contribute to the very process that they are part of. Each year they produce an annual crop of leaves that fall to the ground beneath them. These become major contributions to the soils that are slowly developing here. It might be hard to believe, but someday thick soils will return to these sites. All this is called forest succession. If people refrain from interfering, then this will eventually develop into a mature forest.
That segues us to yet another major component of the post-quarrying ecosystem: the marsh ecology. At the end of quarry work these were low lying sites, underlain by impermeable bedrock. Rains formed pools of water and those, in turn, saw their own sort of ecological succession. Remember those oak leaves? Well, if you visit these quarries you will see these very wet ecologies. The original pools of water eventually became filled with leaves and the work of decomposers formed a primitive sort of soil from them. When such soils were well enough developed, they allowed the growth of large water-tolerant marsh grasses. These small marsh ecologies can be seen here and there throughout the quarry complex. This is another strategy that Nature is using in her recovery.
In the end, what we are seeing here is a process that will require centuries to complete. We foresee, in the very distant future, a return of something approaching the original forest ecology that was here more than a century ago. The message is a clear one; given a chance, Nature recovers from the awful things that man does. We have known this for a very long time. We are temporary; Nature will be here for a very long time.
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