Archivos de diario de octubre 2015

26 de octubre de 2015

On the cliffs of the Octoraro

For several years, I've been trying to get at a walking fern locality in the western part of the Goat Hill tract of William Penn State Forest. It's located above the steep southwest bank of Octoraro Creek, overlooking the bottomlands across the creek where Wood's Mine once tunneled 720 feet down along a chromite vein. These are the "cliffs of the Octoraro" once studied by Francis W. Pennell.

Pennell may have reached the western cliffs by what maps still show as Gray Horse Road, but this old county road has since been abandoned and turned to private driveways. While hunting Adiantum for my research, I tried to reach this area by bushwhacking down Pine Run from the Rose Trail and following the Octoraro downstream. That bushwhack was something of a nightmare in and of itself; below the mouth of Pine Run, an irregular fisherman's trail clings to the steep slope, invaded by stiltgrass but still sprouting Adiantum and Campanula rotundifolia for some distance, crosses an alluvial terrace with relatively open woods—and only then does one reach the truly steep slopes of the "cliffs". Even when the journey to the Octoraro was eased by cutting across a neighboring property, I've never been able to penetrate any great distance along the cliffs before turning around in enervated frustration. I did briefly visit the site, after asking permission from one of the neighbors to cut up the old Gray Horse Road, but I was busy sampling Adiantum and didn't have time to mount an extensive search for walking fern.

Frankly, I've always found this part of Goat Hill a bit unsettling. I'm not usually bothered by the prospect of bushwhacking or being "deep in the woods", but even when you can see the old Wood farm right across the creek, there's a feeling of remoteness and isolation here. I think it's mostly an effect of the terrain and the vegetation: there's a lot of up and down just getting here, often over narrow and treacherous trails, and the close embrace of the greenbriar, in many places, doesn't really leave you with an alternate route out. If you struggled in, you'll have to struggle back out again.

Anyway, it turns out that there's an alternate route down to the terrace along the Octoraro that branches from the Rose Trail and is being maintained, in part, by the Boy Scouts of Camp Horseshoe. I figured that if I could follow a trail most of the way to the cliffs, I'd be less worn out and ready to tackle the journey, and as a bonus, I might find some of the Goat Hill chickweed that grows at the tops of the gentler eastern bluffs. The trail runs, in part, south of the contact line between the serpentinite that underlies Goat Hill and the adjacent metagabbro. Off serpentine, the deciduous forest is open and largely greenbriar free, and at this time of year, full of delightful fall color. I noticed a southern red oak leaf (Quercus falcata); it's uncommon in Pennsylvania and doesn't come much further north. I've seen it growing in the oak groves around the Nottingham parking lots as well. There was indeed some of what I believe is the "very hairy chickweed" (Cerastium velutinum var. villosissimum) growing along the trail—this variety deserves a closer genetic examination, which I hope I can work on in the next year or two.

It wasn't very far from the trail to the edge of the high western cliffs, and I quickly found going just as difficult as ever. The slopes are high, steep, and for the most part, covered in greenbriar (Smilax rotundifolia). Drainages and game trails open narrow gaps, often full of stiltgrass (Microstegium vimineum), in the greenbriar, which the explorer perforce must follow. Much of the greenbriar is sparse enough, and no higher than knee height, that it can be forced with some annoyance, but the thickets atop the bluffs are denser and taller. In the open drainages, northern maidenhair fern (Adiantum pedatum) is common, and it seems as though every substantial rock has one or more ebony spleenworts (Asplenium platyneuron) growing on it. After 20 minutes or so spent struggling along the bluffs, I realized that at this rate of progress, I wasn't going to reach my objective, and might not make it out before dark, either. Struggling upwards, I made the questionable decision to try to strike south for the state forest boundary (close, here, where the creek swings close to the Maryland line) and a possible firebreak to follow. This involved forcing my way through the lush greenbriar at the bluff top by such openings as I could find (one of which held a nice clump of cranefly orchid). Amazingly, the gamble paid off without too much blood loss; there wasn't a firebreak, but I got south of the geologic boundary again and could travel west along the boundary blazes through a relatively open forest with spicebush and pawpaw in the understory.

With my time running out, I finally reached an insurmountable obstacle in the form of "Deep Hollow": a little stream draining the country behind the bluffs has cut a steep vertical-sided ravine through the cliffs to empty into the Octoraro, and I didn't have the time left to pick my way around or across it to reach my site. The eastern slopes of Deep Hollow where it breaks through the cliffs are covered in loose rock which, though presumably ultramafic, doesn't support greenbriar; I peeked around the cliff, and the steep slope down to the Octoraro was mostly bare with scattered Christmas ferns (Polystichum acrostichoides). On the southern and western sides of the slope, above the hollow, the rocks were usually mossy and the predominant herb was marginal wood fern (Dryopteris marginalis) with the occasional maidenhair; the ebony spleenworts didn't seem to have taken up residence.

I wound up cutting back more or less due east, following the state forest boundary through open, non-serpentine woods, until I got back to my original trail and I could follow the established trail network out. The colors on the barrens are beautiful this time of year; the russet of the little bluestem (Schizachyrium scoparium) nicely complements the fall foliage. I came back up the powerline cut with the sun setting at my back and reached my car in the twilight. What a trip!

Publicado el octubre 26, 2015 04:33 MAÑANA por choess choess | 7 observaciones | 3 comentarios | Deja un comentario