One
hundred forty years ago, an intense corporate rivalry inadvertently
produced the largest wetland in Montgomery County, located just a quarter-mile
south of the Pennypack Preserve. In the mid-1870s, the Pennsylvania Railroad and
Reading Railroad each were desperate to build a railroad linking
Philadelphia to New York City. The Pennsylvania Railroad chose a route
that was slightly longer but which incorporated a straightaway that ran
level and flat for dozens of miles along the Huntingdon Valley geological fault. The
Reading Railroad selected a shorter, more direct route that used the
water gap eroded by Pennypack Creek to penetrate the high, steep northern face
of the geologic fault at Welsh Road. Each railroad company had to place tremendous
quantities of fill in the wide floodplain of the creek in order to raise
its tracks out of the floodplain, and this fill, in turn, impeded
drainage toward the creek, thereby impounding the 40-acre Bethayres Swamp with
which we are blessed today.
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| Field trip participants on the former Reading Railroad bridge over the swamp drainage channel |
Because
the wetland includes habitat that is unusual in southeastern
Pennsylvania, the Philadelphia Botanic Club scheduled a field trip to
visit the site on Saturday morning, June 6, and they asked me to come
along for the walk. Though I have walked in the wetland proper a few
times, I usually stick to the railroad tracks when I explore. The
Reading Railroad tracks have been removed and are now part of the county's Pennypack Trail; the Pennsylvania Railroad
tracks are still in use for commuter rail service on the West Trenton line.
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| Making our way down from the railroad bed to the marsh |
The
water in the wetland is deepest near the rail lines, then the land
gradually slopes upward and becomes drier as the distance from the
tracks increases. Nearest the tracks, the wetland is a marsh with dense
emergent herbaceous vegetation. Further uphill, the vegetation grades
to shrub-swamp. And, in the driest areas, the wetland becomes a red
maple-pin oak (Acer rubrum-Quercus palustris) swamp forest. Our
group of seven walkers at first scoped-out the wetland from the elevated
railroad tracks, and then skidded down the embankment and "took the
plunge" into the jungle led by yours truly, who got tired of just poking
around the edge. Fortunately (for the hike), we hadn't had much rain
lately, so the wetland had little standing water and just a few inches
of organic ooze.
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| Let the botanizing begin! |
Almost immediately, we came across a pair of Eastern Box Turtles (Terrapene carolina carolina) in flagrante delicto; alas, they disengaged immediately.
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| The female half of an Easter Box Turtle pair |
Further into the marsh, we found a nest likely built by Red-winged Blackbirds (Agelaius phoeniceus) last summer suspended between a few twigs .
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| Last year's nest, probably from a Red-winged Blackbird |
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| An abundance of sedges (very challenging to identify) |
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| Field trip leader Joe serving as a backdrop for pictures of a blooming sedge |
One of the plants we were especially interested in finding was lizard's-tail (Saururus cernuus).
It's not that rare, but it's an interesting wetland obligate that's not
extraordinarily common. I was the first to come across the plant, but as we continued across the
marsh we found huge expanses of the plant.
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| Our quarry: Lizard's-tail (Saururus cernuus) |
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| One of my favorite plants: parasitic dodder (Cuscuta spp.) (the orange "silly string") How cool is that? |
We
finally emerged from the marsh and shrub-swamp into the drier swamp
forest. Here, there's no understory to impede walking because the large
deer herd that finds refuge in this isolated pocket of wilderness eats
most regenerating trees and shrubs.
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| Pin oak-red maple swamp forest in the driest parts of the swamp |
Honestly, I wasn't looking forward to participating in this walk. It was on a Saturday
morning after I had just worked a full week, and it involved a trudge
through mud and extremely dense vegetation (think African Queen here). But, you know what? I had a great
time! I got wet and muddy and the participants were enthusiastic. When I got
back home and told my wife about my morning, she said, "Despite your
belly-aching, I knew you'd have a great time!" She knows me better than
I know myself.
Submitted by David Robertson
Executive Director
