April 22 (Sunday), on the “Up and Over” (Earth Day 2007)
It was a perfect day: warm and sunny with a Colorado-blue sky. Deborah and I (and our dog, Kozmo) headed up the ridge trail from the Roaring Run parking lot just outside of Apollo. We were hoping to shake off the rust of winter and see if all of the treadmill and exercise bike work during the cold, snowy months had done enough to keep our hiking and climbing muscles in shape.
The first part of the hike was all uphill. A narrow, occasionally gravel (but mostly dirt) truck trail runs straight up the ridge and passes several gas wells and pipeline access points. Last year, the trail was almost completely closed over with encroaching knotweed (that bamboo-like plant that is engulfing old railroad right of ways and most of our river banks) and the trail up was more like a low-headroom tunnel through a mass of interconnecting stalks and leaves. Today, though, the knotweed had been extensively cut back and the trail felt more like a boulevard than a path through the woods. There were, however, thousands and thousands of reddish knotweed leaf clusters pushing up through the soil all along and all over the path. By July this trail could be a tunnel again or it maybe even be impassable.
We strode up the hill and felt better than we feared we would. It was novely strange to feel warm and sweaty after the long months of cold. The sun was hot and dry on our necks and arms and even caused a flush of sun burn and a line mark of my short-sleeved shirt (I have to remember sun screen from now on!).
Multiflora rose was the main shrub leafing out along the path. This rose is an exotic, invasive species that has ‘escaped” from gardens and hedges to which it was introduced back in the 19th century from Asia. It has become a very serious pest of our woodland and rangeland ecosystems. Looking out across the ridge from the top of the trail (where we paused to get a quick drink from our water bottles and to catch our breaths (we were not in perfect hiking shape yet!)) we could see the scattered and, in places, almost continuous masses of the light green leaves of this plant. If left undisturbed (which is a very good idea when you consider the number and sharpness of its thorns!) multiflora rose will form great dome-like masses of intertwined stems. Old, brown and dry, thorn-filled stems fill the inner volume of the dome, and green, flowering, but still thorn-covered stems cover its outer surfaces. Other plants are shaded out and destroyed under and within the growing mass of the rose. This plant represents a very serious threat to the less aggressive, more slowly growing, native plants of our forest and grassland ecosystems. Many small animals (birds, rodents, rabbits, etc), though, use the rose thickets for shelter and for their nesting and denning sites. This mutualistic symbiosis, though, does not off-set the potentially calamitous impact that this species is having on our native flora. In some states, it is actually illegal to have a multiflora rose plant growing on your property! Looking out across the ridge, we saw an incredibly large number of these plants and could only imagine that their abundance and distribution will steadily increase over the coming years.
Another exotic invasive plant that was also present in great abundance along the up-ridge trail was garlic mustard. Garlic mustard is a plant native to Europe and via vigorous seed production and some serendipitous seed dispersal mechanisms has spread itself to almost every temperate zone ecosystem. A single garlic mustard plant in its second (and final) year of life is capable of producing up to eight thousand tiny seeds that spread out though the soil of their ecosystems. These seeds, then, cling to the feet of passing animals and can be spread everywhere that animal walks. These seeds also gather on the boots and clothing or equipment of any human moving though the system, and wherever that person goes, so go the seeds! The rate of these dispersions and the distances that are covered are incredible. On our campus nature trail, for example, we had no detectable garlic mustard back in 1985 when we did our first flora survey. In 2007, though, the understory flora, especially in the upper part of the trail, is absolutely dominated by it. The garlic mustard (whose leaves smell fresh and garlicky when crushed) was also thick and flourishing all along this ridge trail. It made a rich green understory layer around the patches of the multiflora rose: a European herb under an Asian shrub filling up the trailside in Western Pennsylvania.
There are several isolated pools of water along this “up and over” trail. One of the reasons we wanted to make this hike today was to check on the amphibians that both inhabit and visit these pools. As I wrote last year, these “vernal” pools exist on the razor’s edge between success (persistence) and failure (drying up). Last spring I was concerned that the lower than average spring rain totals would cause an increased failure rate in the pools and would, therefore, lead to a high reproductive failure rate in our local amphibians. Fortunately, last year, the May and June rains kept the pools full and the salamanders, frogs, and toads did quite well up on these ridges. This year, the abundant rain and snow have resulted in very full pools but the continuing cool temperatures have both delayed reproduction and also slowed down the rate of egg and tadpole maturation. The pools are full of great masses of amphibian eggs but there had only been a hatching of one type tadpole. These relatively small, dark tadpoles were concentrated down in the sunnier (i.e. warmer) end of the long pool. The larger eggs looked healthy (and like last year, many were bright green with symbiotic algae which have been shown to be of benefit to the developing embryos) but they were at least two weeks behind their development stage of last year.
After we passed through the area of the long pool, we dropped down to one of the most beautiful sections of the trail. A forest of hemlocks and big toothed aspen trees all of which were about 40 years old (representing a re-planting of a strip-mined area perhaps?) generated an extremely quiet, shady, and picturesque trail environment. The hemlocks are a tree species that is native to this area, the aspens, though, are not. They are trees of more northern and more mountainous locales and were probably selected for this reforestation project because of their ability to grow very rapidly and tolerate very sunny conditions. They don’t live very long, though, but are an important component of a “pioneer” forest that can quickly establish itself on barren or disturbed land. So, we could look upon the aspens almost with the same distain as we look upon the multiflora rose and garlic mustard. But, the aspens are so elegant and regal looking. It is hard to consider them as exotic invaders.
Much of this area of the Roaring Run and its adjacent Rock Furnace Trails was, back in the 1830’s, part of a large multi-thousand acre forest site that was repeatedly harvested to feed the charcoal piles that were then used to fuel the crude, iron furnaces. During the era of these furnaces, forest ecosystems were cut and charcoaled and then left to re-grow only to be re-cut and re-charcoaled years later. Crews of wood cutters circled through the thousands of acres around each furnace to generate sufficient fuel for the iron generating process. The remains of one of these stone furnaces can be seen opposite the very large “Camel Rock” on the Iron Furnace Trail. There are isolated stands of young hemlocks along this Iron Furnace Trail that appear to be clustered around older specimens that may have survived the furnace harvest. The locations of these tree clusters and their growth dynamics would make a very interesting study. The hemlock forest of this upper trail, though, is definitely human generated, fairly recent, and obviously homogenously aged.
Around the long pool we saw a pair of veeries (a small thrush) flitting in and out of cover. Their movements appeared to be centered around a space in some low tree branches in which, we speculated, they were building a nest. We watched them but didn’t go too close for fear of frightening them away from a very ideal nesting site. Entering the hemlocks we then saw an eastern towhee and a pair of warblers which we tentatively identified as cerulean warblers. The relatively plainly marked female (which of course was the bird that spent its time on the outer edge of it thicket) was difficult to precisely identify. We did see blue flashes of the male deeper in the branches and could tell that he lacked black markings on his throat, and, so, we came to the “cerulean warbler” conclusion. Also, just before we entered the hemlock stand, we saw a black cherry tree with two large, freshly chipped out, vertically arranged, rectangular holes which we assumed, by their shape and size, were made by a pileated woodpecker. Looking into the literature, I found an almost identical set of holes in a U.S.Forest Service publication. These holes were identified as pileated woodpecker feeding holes (the bird was after ants that were living in the tree). Looking more closely at the picture, I realized that this forest service picture, too, was of a black cherry tree.
Hiking down from the ridge and crossing over Roaring Run stream (there is a wobbly plank bridge there now which Kozmo wanted nothing to do with! Why walk when you can swim? (It wasn’t quite THAT warm!)) we came across great areas of wildflowers. The trillium is abundant and starting to open, Dutchman’s britches are still in flower, and blood root, trout lilies, and even some spring beauty still are all making the hillsides up and around the streams stunning in the beauty and color. These flowers alone are worth the hike, but when you add warblers and towhees, and salamander eggs, sore feet and tired legs are a small price to pay.