Signs of Summer 13: Hiding Extreme Disturbances

Trees near overlook point in Harrison Hills Park. Photo by D. Sillman

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The first Europeans to see eastern North America were overwhelmed by the extreme “tree-ness” of the place. Gigantic white pines and hemlocks, immense oaks and chestnuts, and a staggering array of maples, beech, ash, cherry, birch, poplar and more filled almost all of the physical space of this vast wilderness. Trees covered the valleys, the hillsides, and the mountain slopes. Trees grew in the wet-muck soils of swamps and bogs and on the bare rocks that capped the ridge tops. Trees covered the rich, fertile soils of the bottom lands and the thin, acidic soils of the mountains. These trees had had uncounted millennia to find their interactive balances, their points of ecological equilibrium and sustainability, and they were growing and stable in their interactive spaces. These forests would have existed for many millennia more, in  fact,  if not for the appearance of those “more than just observing” Europeans who also brought with them axes, and saws and oxen and eventually logging railroads.

Not much of the untouched forest still exists. In Pennsylvania, for example, only 5% of the original forest, in the form of scattered, small parcels, still stands. Our European ancestors used the wood from the primal forest for fuel, for shelter, and for a myriad of other products. They cut down the forests and often left them to repair and re-grow on their own. The places where these primal forest stood filled up with types of trees that have only had a few decades to work toward their ecological homeostasis. These new forests are made up of mostly quick seeding, fast growing, short-lived tree species that have molded themselves to the less stable conditions of their modern existences.

We can see some features of this robust forest re-growth by looking at land that has been severely disturbed and left to recover on its own. Which gets us to some observations in Harrison Hills Park along the 5.2 mile park trail called the “Scouts’ Trail,” and, next week, to an interesting New York Times OpEd about New York City’s largest landfill!

Just outside the “dump trail.” Photo by D. Sillman

Deborah and I first hiked the Scouts’ Trail 8 or 9 years ago. Along its path you can see almost all of the possible habitats of Harrison Hills. You go from the highest sections of the park (the cell phone towers up on the hill on the north boundary) down into wet, muddy hollows. You walk across open, grassy meadows, past sunny ponds and wetlands, and through shady forests dominated by black cherry, maples and oaks. One section of the trial, though, caught our attention even on our first through-hike many years ago. In the southeast quadrant of the park the Scouts’ Trail  makes a sharp “V” around the edge of an apparent hill. At the point of the “V” there is a bench that looks over the steep cliffside down to the Allegheny River. All along this section of the trail, on both arms of the “V,” there are flickers and shards of broken glass dotting the trail, and all up the bordered hillside glass, metal and ceramic debris are eroding out the leaf-covered soil.

Emerging trash from the old Harrison Hills dump. Photo by D. Sillman

This hill is an old dump that was part of the donated farm that in the 1970’s became Harrison Hills Park.

The Pennsylvania Waste Industries Association indicates that prior to 1968 there were thousands of active, unregulated sites across the state into which municipal waste, industrial waste and toxic waste were indiscriminately dumped. The passage of the Solid Waste Management Act in 1968 and its subsequent amendment in 1980 and then comprehensive re-writing in 1988 (as “The Municipal Waste Planning, Recycling and Waste Reduction Act”) established the regulations and oversight for our current landfill and recycling systems.

Along the dump trail at Harrison Hills. Photo by D. Sillman

The dump at Harrison Hills Park long predates the 1968 regulations and was, undoubtedly, one of those thousands of unregulated dumps that received municipal waste from nearby communities. Few records would have been kept by the landowner of the dump and little monitoring of the nature or even the volume of the waste materials being disposed at the dump site would have been done. Rehabilitation or restoration of the dump might have consisted of simply covering the mounds of waste material with soil and then waiting for something to grow on top of it!

Photo by D. Sillman

The hike to the V-shaped loop around the old dump starts in a parking area near a large, heavily used playground and runs past a Japanese-style bridge that spans a narrow gully. It then follows a narrow trail over the gently rolling terrain. The trail is bordered (like most of the trails in Harrison Hills) by a dense growth of thigh-high stilt grass (an Asian invasive plant that is steady swallowing up almost all of the native vegetation in the park). Black cherry trees are abundant along the trail. Most of these cherries are about 50 years old and most are well pocketed with pileated woodpecker holes. The cherries were among the first trees that colonized the abandoned farmland (and the shallowly covered dump). Birds readily spread the cherry fruits and seeds, and the germinating cherry seedlings grow

Mile-a-minute vine along trail. Photo by D. Sillman

vigorously in the full sun. There are also some northern red oaks along the trail. Some of these may have arisen from bird-transported acorns while others (especially the double-trunked red oaks) may have sprouted from stumps left behind after land clearing. Spicebush also grows thickly along the trail along with scattered stands of multiflora rose (another Asian exotic invasive). Mile-a-minute-vine (a more recent but particularly insidious Asian invasive plant) is also growing over the tops of many of the shrubs and tall plants along the trail.

The packed soil of the trail surface is extensively punctured by clusters of pencil-sized, round holes. These are the emergence holes of the periodical cicadas that dominated the park for three weeks back in June. This section of the trail must have been a robust incubator for these seventeen-year cicadas!

Ravine along dump trail. Photo by D. Sillman

Mixed in with the black cherry and the red oaks are red and sugar maples and black locust trees, and then, as the trail begins to circle around the tip of its “V” there are some large white oaks and chestnut oaks growing on the trailside away from the mound of the dump. The trail is a boundary between the dump and a more “pristine,” surrounding forest: small diameter, evenly aged trees (mostly black cherry) are growing in the soil-covered spoil of the dump while larger (two or three

Silt grass growing over old dump. Photo by D. Sillman

foot diameter) oaks are growing in the undisturbed soil outside the margin of the spoil. It is impressive, though, how thickly the trees and shrubs (not to mention the stilt grass!) are growing on the glass and metal laden spoil! Most of the dump is covered by a dense mass of woody vegetation. The dump, except for the emerging debris, is very well hidden by its entangling vegetation! When I step off the trail out onto the spoil (I am wearing thick soled boots, of course) I feel the solid nature of packed spoil and covering soil. I can’t walk very far into the dump area, though, because of the density and tightly intertwined nature of its covering vegetation.

As I was walking about and paying attention to the trees and shrubs around me, I nearly stepped on a large, still green, big-toothed aspen leaf that was laying in the middle of the trail. I stopped and looked for the aspen tree but only saw black cherry, sugar maple, and various oaks. The leaf must have just recently blown down (it was nearly as green and as full of chlorophyll as it had been while it had been attached to its tree!), but it must have traveled a long way before it came to rest. Unexpected.

Photo by D. Sillman

Signs have been placed at the ends of the “V” around the dump warning hikers of unsafe trail conditions, and a cutoff trail has been opened to allow hikers to avoid most of the debris. There has been some discussion among the park authorities as to whether the eroded glass fragments represented a true hiking hazard or just a curiosity. At a meeting this summer it was decided to keep this trail section open but to establish a set of informational signs to explain the presence of the glass and other debris. The dump is observable only in the glimpses of these fragments. The dump, though, is an important part of the human history of this site! The covering trees and shrubs and herbaceous plants have done an incredible job in obscuring the nature and extent of this unfortunate place. We need, though, to see this “hillside” for what it really is!

(next week: the Fresh Kills Landfill on Staten Island!)

 

 

 

 

 

 

 

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One Response to Signs of Summer 13: Hiding Extreme Disturbances

  1. Donna L. Long says:

    Hi, I liked your essays. I tried to “like” it but something weird happens when I click “like” it won’t register. 🙂

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