Frigid Field Trip

I'm teaching two Landscape Restoration classes on Fridays this term, first for 10 graduate-level landscape architecture students, and then for 27 undergraduate landscape architecture and horticulture students.  I escorted the two classes on a field trip at my preserve last Friday (February 27).

The trails in the preserve were (and still are) very icy.  Three of the graduate students slipped; none of the undergrads did, perhaps because by the time the undergrads showed up the sun had warmed the snow and ice a bit.

It was in the mid-teens F when we started out in the morning, but it was sunny and not too windy.  I had considered postponing the trip, but then decided to proceed as planned.  If I had postponed, who knows what the weather would have been like on the next scheduled date.

The last two weeks of February were the two coldest weeks ever recorded in Philadelphia - not just for February, but for any two-week period since records have been kept (1841).  February 2015 was also the fifth coldest February on record.

My Stewardship Assistant, Chris, explaining how he manages our native prairie

Yours truly in the midst of our oldest reforestation project (25 years this year)

The undergrads examining a lesion caused by the chestnut blight fungus on one of our American chestnut trees

A Ray of Hope

On Friday morning, February 13, I joined my landscape restoration students for tours of an urban oasis featuring the latest stormwater management and native gardening concepts.  My graduate students gathered for their tour at 8:30 a.m., and then my undergraduates met at 11:00 a.m. for a second tour.  When we got to the site, the temperature was 8 degrees F, and the wind was blowing strongly.  To say it was cold was an understatement, and the temperature had only risen to about 18 when the undergraduates convened for the second tour.

The site was the Salvation Army's Ray and Joan Kroc Community Center in Philadelphia.  Ray Kroc, founder of McDonald's restaurants, and his wife, Joan, gave the Salvation Army over $1 billion to build community centers in severely disadvantaged urban neighborhoods across the country.  I'm not much of a fan of the Salvation Army (because of their discriminatory practices) and everyone has an opinion about McDonald's.  Our tour leader, Chris, shared my opinions about both organizations, but he conceded that the community center was a godsend for the impoverished neighborhood in which it was located and he commended the Salvation Army for its good deeds here.

The site had been a lightly-contaminated brownfield associated with the Budd Manufacturing Company, one of Philadelphia's largest employers when manufacturing was king.  Budd's thousands of workers built zeppelin gondolas, railroad cars, and airplane parts.  Today, the factory buildings are vacant, derelict and marred by graffiti.  The 13-acre Kroc site had been a parking lot for Budd's workers.

When the Salvation Army decided to locate the community center on the site, they hired the local but widely-renowned landscape architecture firm Andropogon (named for a genus of native grasses) to design the landscape.  With Philadelphia's extremely strict  stormwater management regulations, the Salvation Army insisted that the designed landscape capture, retain, and infiltrate as much water as possible.  Andropogon's designers also decided to make the project "zero waste" - no material would be removed from the site.

All of the existing parking lot pavement was either recycled to be reused for porous pavement on the new parking lot or was spread to level the site.  Slightly contaminated soil was buried deep under the site and encased in compacted soil.

Bioswale

The new porous pavement parking lot was divided into sections separated by bioswales.  Any stormwater which does not drain through the porous pavement runs into the bioswales planted exclusively with native species.  Stormwater which fails to infiltrate in the bioswales is gathered into one location and diverted to an extended detention and infiltration basin called Rain Garden B.

Roof stormwater management system

The community center building covers two acres.  The architects determined that installing a green roof would have been prohibitively expensive.  So, instead, they worked with Andropogon on an alternative.  Rain falling on the roof collects in three locations and spills into downspouts integrated into the building's design.  The spouts discharge into decorative runnels, which direct the water into one of two cisterns buried in the center of the site.  The cisterns were designed to supply water to the property's landscape irrigation system but, unfortunately, the irrigation system failed soon after it was completed and now the cisterns simply discharge into Rain Garden A when they are full.

Cleverly disguised downspouts and decorative runnels

Tour leader Chris demonstrating the capacity of the runnels

Small rain events fill just the central sculpted channel in the runnels, while larger events fill the broader channel.

Sculpted runnel designed to look like flowing water

Students standing at he edge of Rain Garden A that receives the discharge from the roof cisterns

All three of the rain gardens on the site were dry when we visited..  If Rain Garden A fails to infiltrate all of the stormwater it receives from the roofs, the excess water can flow into Rain Garden B, which collects water from the parking lots.  And, if Rain Garden B cannot infiltrate all of the water, the excess flows to Rain Garden C, which also includes a structural outlet to the city's stormwater sewers - a "fail safe" in the event of a major flood.  Chris emphasized that Rain Garden C had never spilled any water into the city's sewers since it had been built (though he admitted that we hadn't had a hurricane yet, either).

Rain Garden B on right of path

Last stop.  Rain Garden C, which can handle the overflow from A and B, if necessary.

The plantings in Rain Garden C included some bald cypress trees in the bottom of the basin.  Bald cypresses will survive this far north, but they are not part of the native flora.  I didn't challenge Chris on the issue, so I can't explain the reasoning behind planting cypress (versus a more northern species that could also tolerate wet feet like swamp white oak, pin oak, or sycamore).  With global warming, the cypresses may be very happy in the near future, but there was no evidence of global warming on the morning we visited!

Pretty Perfect Weekend Field Trip

I'm teaching ecological restoration at the University of Pennsylvania this term as an Adjunct Professor.  It's a class for graduate students, and I have taught it every other fall term since 1992 - that's 22 years now, about as long as some of my youngest students have been alive.

I'd like to take the students on a lot of field trips.  The more that they can get out in the field to see actual restoration work, the better.  But UPenn is very near the heart of Philadelphia and it's hard to get to a site, take a tour, and get back to campus in the allotted 3-hour class period.  So, I always offer a weekend field trip to my preserve.  We did the trip this last weekend.

Many of the students are foreign nationals, and most don't own cars, so they use the regional rail network to get near my preserve, and then Kali and I pick them up at the train station.  Yesterday's trip started off badly - a 60-year-old man walking on the railroad tracks was struck and killed by a train (it happens more often than you might imagine; most victims are suicides), which delayed the start of the trip by one hour.  But the students all finally arrived and we enjoyed two hours of nearly perfect early autumn weather.

Return to High School Park

High School Park Stewardship Manager Kevin preparing a dogwood live stake

A year ago, I brought my undergraduate Landscape Restoration students to High School Park, a 10-acre municipal park in a Philadelphia suburb that a non-profit "friends" organization adopted in order to re-establish native ecosystems on the site of the community's old high school.  At the end of our field trip in 2013, as I was preparing to leave, a young man came by walking his dog and we struck up a conversation.  It turned out that this fellow, Kevin, was enrolled in the graduate landscape architecture program at the university where I serve as an adjunct instructor, and that he had just applied for the part-time Stewardship Manager position at High School Park.

I needed some part-time help in my preserve, so I asked Kevin to call me if he found that he had some time.  Kevin got the job at High School Park, and he did some restoration work for me, too, all while trying to finish his Master's degree (which he will do next month).  So, when it came time for a field trip this year, I asked Kevin to escort my students - graduate students this year - around the park, which we did on a drizzly, cold April 3 morning.

An introduction to the restoration work

We spent a lot of time in the floodplain of Tookany Creek, which forms the northern border of the park.  Like all the streams in the Philadelphia suburbs, Tookany is a "flashy" stream that roars after rains and then dries up to nearly a trickle between storms.  Water quality is "impaired," a polite term for terrible.  The streambanks are constantly eroding, and much of the work in the park is dedicated to trying to stabilize them as best as possible. 

Considering options for streambank restoration in an urban watershed

The municipality has spent a lot of money installing "cribs," telephone poles anchored into the streambank and filled with soil, then planted with trees and shrubs.  The cribs hold for a while, but inevitably the stream begins to erode behind the structures, which usually results in a catastrophic failure during a major flood.  In the lower right of the image below, the upstream end of one of the cribs is visible.  If it doesn't receive some attention soon, that crib is doomed.

Downstream view of Tookany Creek with crib 

Though spring is finally getting underway here in the northern Piedmont, only a few flowers have dared to blossom yet.  One that is not so shy is lesser celandine, an invasive buttercup that carpets our urban and suburban floodplains excluding native spring ephemerals.  Though the plant flowers profusely, ecologists believe that tiny bulbettes attached to the tops of the roots are actually more responsible for its spread than are its seeds.  Because he plant favor floodplains, the bulbettes detach from the mother plant and wash downstream during floods, establishing new colonies.  

Lesser celandine (Ranunculus divaricata)

The site of the demolished high school on a plateau above the creek has been converted to a meadow.  Though the "friends" have tried twice to create a meadow dominated by native species, the meadow consists mostly of non-native, invasive weeds.  The repeated failure can be attributed to the fact that the building was bulldozed into its basement, leaving a calcium-rich, high pH substrate for plants that prefer low pH soils.  In addition, the layer of topsoil spread over the site was far too shallow to support most native species.  Scheduling difficulties with the planting contributed to the failure.  And, finally, becaue the park is public property, the private "friends" group cannot apply herbicides that might help keep the weeds in check.   

At the edge of the "native" meadow

Kevin also has to beg for help from the municipality's parks department, which has mowing equipment that the "friends" group cannot afford.  While the park employees try to be helpful, sometimes they act more like "cowboys" more adept at mowing large expanses of turf.  Two weeks ago, the park guys mowed down shrubs planted at the edge of the meadow - another setback.

Colorful stakes failed to prevent the parks "cowboys" from mowing shrubs

At the end of our tour, Kevin showed the group some "planting logs" he invented to try to speed-up the development of a riparian shrub layer.  Kevin creates a "burrito" of mulch and soil wrapped up tightly in burlap, and then he inserts dogwood cuttings into the logs.  He keeps the burritos moist, which encourages the dogwood cuttings to develop roots.  Then, he takes the rooted logs down to the streambank and secures them with more dogwood cuttings in an effort to jumpstart a stabilizing shrub cover.

A burlap planting log

How Kevin will secure the rooted logs onto the streambank

Back to High School...Park

Amy, a board member of Friends of High School Park showing off a new informational sign

I took my undergraduate Landscape Restoration class on a field trip to High School Park on Thursday (April 11).  I've profiled High School Park several times before in this blog; it was the site of a stone and brick high school that was abandoned when the community built a new high school.  The building was vandalized and burned, then finally demolished by bulldozing all of the debris into the basement.   The municipality purchased the 9-acre parcel from the school district and turned it into a municipal park.  The Friends of High School Park were formed soon thereafter to look after the parkland, and to try to restore native plant communities on the site: native grass meadows on the plateau where the school had stood, mesic woodlands on the steep slopes below the meadows, and riparian forest along a "flashy," flood-prone suburban stream called Tookany Creek.

We began our tour in the meadows, escorted by one of the Friends' board members, Amy, a good friend of mine.

This actually was the second meadow installed on the site.  The rubble from the building was covered with only a few inches of soil, so the calcareous debris sweetened the soil so much that the acid-loving native grasses and perennials that were planted on the site languished and were quickly overwhelmed by weeds and invasive plants.  This time around, the Friends got a grant from the state to restore the meadow, and planned to do it "right," with soil amendments to make the soil more acidic, followed by a planting of native grasses, and then a planting, one year later, of native wildflowers.  However, time constraints imposed by the state grant required the group to plant all of the plants together, which will not allow the grasses to get established before the wildflowers are added as the group  had hoped.  Unfortunately, I do not predict good things for this meadow.

This meadow is not going to "cut the mustard"

Non-native plants and grasses are evident everywhere in the meadow, and controlling them is going to be a yeoman's task.  At one point, we stopped at the edge of the meadow in an area sporting a huge patch of a non-native mustard - a typical challenge facing the Friends.  The Friends are not allowed to use herbicides (this would be a private group applying herbicides on public land - a real no-no, even if the Friends had someone certified to apply herbicides, which they don't).  The municipality's public works department has a certified applicator, but that individual has little or no time to devote to High School Park.  So, it's all hand-pulling, mowing, and cutting by volunteers.  Yikes!

When we came to the mustard patch, I invited the student to pick a few leaves from the plants to see how they tasted (very sweet and a bit spicy).  This completely freaked-out my students, who were sure that this was the last they would see of their instructor.  I can almost always freak-out group when I'm giving a tour if I nibble a plant.  Urbanized people are so divorced from the natural world that the thought of eating anything that doesn't come from the supermarket upsets them.

Stopping to discuss the value of meadows as a source of bird food:  insects and caterpillars

Some of the same meadow species, now up close and personal

After circling the meadow, we came to a garden with benches and paved walkways.  The Friends plan to use this spot as a demonstration garden to highlight many of the species planted in the meadow but in a format that is accessible to the public in attractive, designed beds.

Reviewing the plans for the demonstration garden

Amy had another commitment, so the students and I finished the tour by walking along the riparian trail paralleling Tookany Creek.

The Tookany Creek Trail bordered by highly invasive lesser celandine (Ranunculus ficaria)

The creek trail is short, and ends at a arbor and a sitting area overlooking the creek.   The wooden seats are shaded by huge specimens of a nasty, invasive shrub, Siebold viburnum (Viburnum sieboldii), a horticultural landscape plant.  Unchecked, this Japanese viburnum can overwhelm the understory of a disturbed woodland in short order.  However, the plant does have one interesting characteristic of which I take full advantage when I lead a group through the woods - when crushed, the leaves of Siebold viburnum are extremely odoriferous.  I love to crush the leaves and watch school children wrinkle up their noses when they whiff the rank odor!

Siebold viburnum about to bloom

April Fool's Day Field Trip

Exploring a stand of old-growth American beech before spring bud break

Every other year, my colleague and renowned restoration ecologist Steven Handel brings a group of upper-level undergraduates from Rutgers University in New Jersey to visit "my" preserve for a field trip to review ecological restoration strategies in a suburban context.  This year, he scheduled the trip for April Fool's Day, which was sunny and reasonably warm.  Chris, one of my land stewards, and I accompanied Dr. Handel and 20 students on a 2-hour walk through the preserve.

Chris (second from right) and Handel (third from right) discoursing on planting trees

Steven Handel lending his support to a large, old beech

On the floodplain

There are certainly no shortage of non-native, invasive plants growing in the preserve, but for some reason Dr. Handel has a special hatred for lesser celandine (Ranunculus ficaria), an introduced buttercup that carpets any land where it gets established.  Since the plant favors (though is in no way restricted to) moist soils along floodplains, Handel really got revved up when we finally got to the stream bank.

Examining celandine up close and personal

Lesser celandine can reproduce three ways: by seed (not commonly), by tiny bulbs, and by aerial tubers that form on the stems.  The plant is especially successful on floodplains because flood waters can disturb or even uproot the plant and distribute the bulbs and tubers further downstream.  It's a lovely plant and I've seen people digging it up, presumably to plant in their gardens, though I warn people when I see them.  They have no idea about the monster they're inviting into their midst. 

I wish I could fish on a Monday afternoon

Before we completed our walk in the riparian area along the creek and headed back uphill, we came across several fishers trying their hand at landing a trout.  The state's Fish and Boat Commission won't stock trout in stream reaches that flow through private land like "my" preserve, but the local Trout Unlimited chapter meets monthly in our visitor center and stocks the creek themselves each year with about 200 brown trout.  Though any- and everyone is invited to fish, the club asks anglers to catch-and release.  Our creek is decidedly not a cold-water fishery, but some of the trout seem to overwinter.  Brown trout are pretty hardy; they're a European import that will take to most any water.

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.