Friday, February 22, 2013

A Drop in the Bucket...but It's a Start

Common cat-tails (Typha latifolia) in the winter marsh
I'm teaching as an adjunct at Temple University this term.  My course is undergraduate Landscape Restoration, and the class took a field trip to a wetland restoration site yesterday afternoon.

Bob Adams, Director Stewardship at the Wissahickon Valley Watershed Association, explaining the project to the students
The area where the wetland was restored had been a municipal softball field, but it was located in the floodplain of Sandy Run, an extraordinarily flood-prone tributary of the Wissahickon Creek.  Bob Adams, our guide and the Director of Stewardship at the Wissahickon Valley Watershed Association who designed and oversaw the construction of the wetland, explained that the softball field was hardly ever used because of wet soil or standing water.  So, the watershed association applied for state funding to restore the site.

Two years and $100,000 later, the 2-acre wetland was completed.  There are still problems with invasive species - especially purple loosestrife (Lythrum salicaria) - but the weevils that have been imported as biocontrols from the plant's native range in Europe seem to be reducing the vigor of the infestation.

Bob Adams showing the students a piezometer used to gauge the groundwater level
Planted trees protected from deer browsing by wire cages
We also walked to the banks of Sandy Run to look over the stream and review the challenges of trying to restore a riparian area near a stream that is so temperamental.

A tree cage damaged by flooding on the bank of Sandy Run
At the conclusion of the tour, the students left the site, but I stayed behind to capture a few more images.

The marsh in winter, partially ice-bound
Last summer's nest, probably built by an American robin (Turdus migratorius)
No one could identify this plant, but I liked its winter profile
Pussy willow (Salix discolor) wands
Silky pussy willow ovaries
Except for the electrical lines, this could be wilderness.  Actually, the site is embedded in the middle of the 'burbs.
This two-acre site represents an infinitesimally small part of Sandy Run's watershed, so the wetland can't possibly have much of an impact on the quality or quantity of water that roars through the valley after a heavy rain.  But, it broadens the riparian area, and it provides habitat for quite a few wetland-dependent species despite its proximity to a busy suburban thoroughfare. 

Tuesday, February 19, 2013

President's Day Cherry Tree Ramble

Climbing to the top of The Peak, a local topographic high point
It's become an annual tradition that I lead a President's Day Cherry Tree Ramble to entertain and educate folks who have President's Day off work (unlike me).  My goal in leading the walk is to enlighten the hikers about the myth of George Washington's chopping down a cherry tree and confessing his transgression to his father, and to show the participants how to distinguish between the native black cherry (Prunus serotina) in our woodlands vs. the introduced bird cherry (P. avium).

Washington's exploit was fabricated by an itinerant preacher and Washington groupie named Mason Locke Weems who published a book called The Life and Memorable Actions of George Washington in 1800.  In the fifth edition (published in 1806), Weems inserted the story about Washington's vandalism to demonstrate the future president's forthright and honest nature.  In reality, very little is known of Washington's early life, and historians are sure this story (among many of Weems' others) has no basis in reality.

Though the day was cold, the sky was bright blue and sunny.  The three hikers and I were accompanied on our walk by a forestry consultant named Joe who has been clearing invasive vegetation from one of our older woodlands in preparation for restocking the forest with new native trees this spring.  It was a convivial group, and the small size allowed us to interact frequently.
Hiker Judy examining the bark of a native black cherry
Native black cherry, when mature, develops a distinctive thick, scaly, dark bark.  The tree can live to be 200 years old, and produces lots of drupes that attract birds, which spread the seeds to new locations.
Forestry consultant Joe and hiker Karen atop The Peak with a bird cherry
In contrast, bird cherry (also called European, sweet, mazzard, or gean cherry), has a smooth bark with distinctive horizontal corky sections called lenticels.  Bird cherry is a short-lived tree (about 50 years) and has inferior value as lumber compared to the native species.  Like black cherry, bird cherry also produces numerous drupes that are consumed (and spread) by birds.  Bird cherry is the species that was cultivated to produce the edible cherries we use in pastries.  Though it was introduced by colonists from Europe, it is native to western Asia.
Consulting forest restoration expert Joe and the hikers looking at invasive vines in the forest canopy

Thursday, February 14, 2013

A Snowy Start

Overlooking the pond behind the house
We went to bed with rain and awoke with a bit snow.  Kali teaches at 8:00 a.m. on Tuesday and Thursday mornings, so we had to get up extra early because of anticipated traffic problems.  Arising before dawn gave me an opportunity to capture some of the snow just as the sun was coming up.  The forecasters are calling for temperatures in the mid-40s (about 7 Celsius) with bright sunshine all day, so this enchanted scene will be evanescent.


Sunday, February 10, 2013

A "Plague" of Robins

Late last week, I commented on a post by Grizz at his Riverdaze... blog that American Robins (Turdus migratorius) had, so far, failed to strip the tiny fruits from my crabapple tree as they usually do much earlier in the winter.  Well, the major winter storm that buried New England and New York only left three inches of snow here in the northern Piedmont, but it was enough to send the overwintering robins into a feeding frenzy.  As I shoveled the walks and drive on Saturday morning, hordes of robins descended on the crabapple tree and feasted.

Just a few of the dozens of American Robins gorging themselves on crabapples
Winter has been pretty mild so far this year, so the birds have found alternate sources of food in the thickets where they hide.  I suspect that crabapples don't have much fat content, so the overwintering berry eaters prefer other fattier fruits.  But winter's winding down now, and the birds have harvested much of the other available fruit; they must be becoming desperate.

My dependents eat even before I do (but I have admit I brewed coffee first)
A Red-breasted Nuthatch (Sitta candensis).  These northern visitors were more numerous at the beginning of winter, but a few have hung around all season.
A few more snowy images.  This was our first substantial snowfall of the season.

View down to the pond behind my residence
The old-field just beyond my front lawn
My Prius is all flocked up
The east end of my residence, added in 1833 to an existing 1791 house

British contemporary dance/movement company Motionhouse performed Scattered in Philadelphia on Saturday night. For 70 uninterrupted minutes Kali and I were mesmerized by seven young dancers interacting very, very vigorously with a "half-pipe" curved wall onto which was projected a video exploring water in all its forms. The piece worked so magically well that I honestly expected the performers to be soaking wet after an extended set in which they played on a virtual waterfall. Bravo, Motionhouse!

Monday, February 4, 2013

Misery and Joy on Groundhog Day

Classic view of Valley Forge - reconstructed soldiers' cabins and open fields
Kali's putting on pounds - she's the first to admit it - in part because she's very sedentary at work.  So, when I proposed a hike on Groundhog Day, she was up for the challenge despite overcast skies and temperatures hovering around 30 degrees.  I looked through my regional hiking guide and suggested that we walk at Valley Forge National Historical Park, a 40-minute drive from home.  We walk at Valley Forge fairly frequently, but we were afraid that our usual walk along the banks of the Schuylkill River might be muddy.  So, instead, I found a 5-mile loop hike that traversed two wooded hills in the western end of the large park,  I assumed that the elevated trails would be drier than the riparian path.  (I was right.)

The paired hills are named Mt. Misery and Mt. Joy.  They are separated by a sizable stream called Valley Creek that provided power for colonial mills.  Valley Forge had already become an important industrial community at the time of the American Revolution.  (Today, it's a sleepy suburban crossroads.)

Kali lunching on an energy bar along the Mt. Joy Trail
We first ascended Mt. Misery.  At the foot of the hill were ruins of a colonial mill with a small spring-fed stream flowing right through the building.  There were no interpretive signs indicating the type of milling conducted here, though milling operations changed frequently in response to local needs, so the mill easily could have processed a dozen different products during its useful life.

Ruins of a colonial mill at the foot of Mt. Misery
We continued our ascent through open woodlands with an understory of mountain laurel (Kalmia latifolia), Pennsylvania's state flower.  The woods support mostly drought-tolerant chestnut oaks (Quercus montana), with smaller numbers of black oaks (Q. velutina) and Northern red oaks (Q. rubra).

Mossy log in the leaf litter
The Appalachian Piedmont is a geologist's dream (or nightmare).  The Piedmont features rocks that have been repeatedly tortured by the tectonic collisions of North America and Africa over the aeons.  As such, metamorphic, igneous, and sedimentary outcrops often occur in close proximity.  Mt. Misery, Mt. Joy, and Valley Creek are good examples.  Mt. Misery and Mt. Joy are composed of quartzite, a metamorphic rock derived from melted and compressed sandstone.  The erosion resistant quartzite hills stand several hundred feet above the surrounding landscape of sedimentary rock.

A quartzite boulder in the woods
A whimsical cairn along the trail
Like nearly all national parks, hunting is prohibited in Valley Forge.  As a result, the population of white-tailed deer has exploded.  Vehicular collisions are common on the roads through the park, the forest understory is completely decimated, and the deer have created a browse line on the vegetation as high as they can reach.  No young trees whatsoever are present to replace the mature canopy trees.  Fortunately, after a decade of documenting the damage, the National Park Service allowed U.S. Department of Agriculture sharpshooters to begin to cull the deer last year.  It's too soon to determine how effective the population reduction will be, but it couldn't get much worse.  Throughout the park's woodlands are dozens of fenced exclosures that were used to demonstrate the effect of deer browsing on the forest understory.

The depauperate woods at Valley Forge, here along the Mt. Misery Trail
After Kali and I descended the far side of Mt. Misery, we walked across meadows of native grasses and down to the banks of Valley Creek.  Valley Creek flows through a limestone valley fed by numerous springs.  As a result, it is the only steam with water consistently cold enough for trout in southeastern Pennsylvania.  There were probably native brook trout in the creek at one time, but fishers have stocked aggressive European brown trout in the stream for angling.  Regardless of the species in the stream, though, none of the trout can be kept - serious PCB pollution in the upper watershed from railroad yards has contaminated the creek, so all fishing is catch-and-release.

Kali on a footbridge spanning Valley Creek
We then ascended Mt. Joy and followed the trail high above the deep, steep valley separating the two hills, ending our walk where we started near the mouth of Valley Creek.  We both enjoyed the hike very much for its invigorating climbs and its novelty.

View westward from Mt. Joy across the Valley Creek gorge to Mt. Misery