Wednesday, October 19, 2016

Wissahickon Part 2: Forbidden Drive

Bell's Mill Road Bridge, viewed upstream
After Kali and I finished exploring Houston Meadows (previous post), which is located on a high, flat bluff above Wissahickon Creek, we descended the steep valley slope to the stream.  An old carriage road parallels the western bank of the creek for seven miles.  Because vehicles are prohibited from using the old road, it is called Forbidden Drive.  Forbidden Drive is one of the most heavily used recreational amenities in the city, with walkers, runners, equestrians, and bicyclists all mixed together in a generally congenial stew. 
Wissahickon Creek downstream of Bell's Mill Bridge
The land that is now Wissahickon Valley Park was a colonial industrial valley with mills and roads throughout.  The city bought the land in the late 19th century because Wissahickon Creek empties into the Schuylkill River just upstream of the city's drinking water intake, so the city wanted to try to preserve water quality in the Wissahickon and the receiving stream.  Nearly all vestiges of the industrial heritage are gone, but many of the stone ruins and the bridges that bore roads over the creek remain.
Blue wood aster (Aster cordifolius) and Wreath goldenrod (Solidago caesia) on the wooded streambank
Forested slope with denuded understory
White-tailed deer have been very abundant in the park.  As a result, nearly all of the forest understory is gone, and few sapling tress are growing to replace the old trees when they die.  For the last decade, the city has hired sharpshooters from the U.S. Department of Agriculture to cull the herd.  The sharpshooters hunt at night over bait, and the venison is donated to local food banks.  Nevertheless, animal rights group protests are a constant thorn in the city's side over this issue.  The culling has significantly reduced the number of deer, and the forest has begun to recover in places.
Parasitic beech-drops (Epifagus virginiana) in a patch of sunlight
One of the reasons that the Wissahickon is so popular is because it is very scenic.  The creek has cut a deep gorge though very hard rock, so the valley slopes are steep with lots of scenic boulders and bedrock exposed.  Because of the steepness, only one old road crosses the valley directly (Bell's Mill Road, the picture at the head of this post), and few roads penetrate down to Forbidden Drive.  Rex Avenue (image below) is one of those roads that descends from the eastern side of the valley and terminates at Forbidden Drive.
Rex Avenue Bridge
Old park guardhouse along Forbidden Drive
Covered bridge, the only one in Philadelphia
Invasive Japanese angelica-tree (Aralia elata), left, and Japanese knotweed (Fallopia japonica)
Wissahickon Creek rapid
Forbidden Drive
Forbidden Drive is not one of Kali's favorite walks because it is dark and claustrophobic; she much prefers the sun and openness of Houston Meadows.  However, I like the views of the creek and the general sense of community among the users.

Tuesday, October 18, 2016

Wissahickon Part 1: Houston Meadows

Bumblebee on goldenrod
Last Saturday (October 15) was an absolutely perfect early autumn day, with temperatures in the upper 60s, crystal clear blue skies, and very low humidity.  I packed Kali into the car and we drove over to the north-westernmost neighborhood in Philadelphia called Roxborough for a hike in the 1,800-acre Wissahickon Valley Park, Philadelphia's largest and best-known park.  Our goal that day, in addition to just getting some exercise, was to inspect Houston Meadows, a restoration project undertaken by the city's Department of Parks and Recreation as part of an ongoing series of natural lands restorations throughout the city's larger parks.
Trail through goldenrod and little bluestem
A few aspens; there are others growing nearby at the edge of the meadow
Native little bluestem (Schizachyrium scoparium)
To my mind, the Houston Meadows project was not a straightforward "winner."  During the early part of the 20th century, the meadows had been an active farm before urbanization expanded outward to the very edges of the city limits.  When the farm was incorporated into the park, the land became fallow and quickly reverted to herbaceous old-field habitat - a "wildflower meadow" in common parlance.  This habitat was extraordinarily attractive to birds and butterflies that needed such habitat, and Houston Meadows became a birders paradise maintained by fires set periodically by neighborhood hoodlums.
Bluebird box on meadow slope
All was well until houses were built up to the very edge of the park, and then the field fires had to be suppressed.  This fire suppression allowed natural succession to kick in and trees and woody vegetation, formerly killed by the fires, began to creep into the meadows, changing the land first to a thicket and then to a young woodland.  The birds and lepidopterans could no longer find appropriate habitat and abandoned Houston "Meadows."
Goldenrod (Solidago spp.), boneset (Eupatroium perfoliatum) and native grasses
With support from a philanthropic foundation, the city decided to try to restore the meadow habitat and attract the birds back.  So, they brought in heavy equipment to clear the trees in the young woodlands, and they seeded the land with early concessional meadow species and native grasses.    

The result has been mixed in my opinion.  First, I have to admit that I don't know if the "target" birds have returned to the meadows.  If they have, they've "voted with their wings" and given the restoration their approval.  But, if the birds haven't returned, the project cannot automatically be dubbed a failure because (1) they birds may not have "found" the meadows yet, (2) the habitat may not have developed enough to interest the birds, or (3) the restored field really might not be suitable habitat.

This section of the meadows almost looks "western," with a big rock and conifers
Where the herbaceous vegetation has gotten established, the meadows are lush, productive and beautiful.  But Parks and Recreation seems (to me, anyway) to have left too many trees in the midst of the fields.  Hawks and other raptors perch in these trees and prey on the meadow-nesting birds.

In addition, the meadows are small and fragmented.  Some meadow-nesting birds seem to need 160 acres of grassland habitat to breed successfully, and these fields are nowhere near that large.  Other species, especially species that like brushy habitat, may be the first ones to recolonize the site.  To my eye, the habitat looks perfect for birds that like scrubby, brushy habitat.
Deer exclosure fencing
Parks and Recreation also included a deer exclosure as part of the project, but it is in a wooded corner of the meadows.  I don't know the motivation for excluding deer from a meadow project, but perhaps they were trying to expand a section of woodland and not develop meadow here.

Friday, October 14, 2016

Just Shed

Kali and I took a walk in my preserve on Wednesday evening after she got home from work.  As we walked along the trail that parallels the creek running through the preserve, I noticed a long snake skin on the ground.

The owner must have shed the skin very recently because it was still soft and supple.

I decided to bring it back to our Visitor Center to put it on display.  However, it drew a lot of attention from other folks walking the trail that evening  I was glad to be an ambassador for the natural world and for our organization.  Maybe I should walk around with it draped around my neck all the time--sorta' like the puppies guys are advised to use to attract the attention of women.
By the way, the owner more than likely was a Northern Water Snake (Neroida sipedon sipedon), which are very common in the preserve.  When I stretched it out to its full length, the skin measured 3' 11".     

Friday, September 23, 2016

Botanical Illustration III - Scratchboard

I completed the third and final class of introductory botanical illustration last evening.  The eight students attempted scratchboard, something I had never tried before.  There's no erasing; no correcting errors.  My results appears at the head of the post.  The instructor and I agreed that I had probably done my best work in the red section of the largest leaf.

I now know that I am sufficiently capable of drawing to tackle other projects, but I'll probably have to wait until I retire to take this up again.  I don't think I'll attempt scratchboard, though; it was frustrating and unforgiving.

Thursday, September 22, 2016


Kali dispersing common milkweed (Asclepias syriaca) seeds
On Sunday afternoon, September 18, Kali and I joined about 20 other guests at a natural area called the Paunacussing Preserve owned by the Natural Lands Trust (NLT), the largest regional land trust in eastern Pennsylvania.  This guided walk was for long-term NLT supporters and was led by Preserve Manager Preston Wilson supported by another NLT staff member and a volunteer.  Sunday afternoon was very warm, humid, and cloudy with thunderstorms in the forecast, but the very much-needed rain held off until Monday morning.

The 100-acre Paunacussing (named for the creek that rises on the land) contains active agriculture, farmland converted to native meadows, meadows undergoing active afforestation, woodlots, and a large pond.  Topographically, it is fairly level and walking was easy. 

We set off on paths cut through native goldenrod meadows in full bloom.

Old fence post festooned with Virginia creeper (Parthenocissus quinquefolia)
Cooperative azure damselfly perched in the meadow
Thistle gone to seed exposing its silvery underbelly
All afternoon long, the sky was full of vultures.  The light wasn't good, the birds weren't close enough for me to get a good "naked eye" view, and I hadn't brought my binoculars, so I couldn't tell if they were Turkey Vultures (Cathartes aura) (the more likely) or Black Vultures (Coragyps atratus).

From the meadows, we moved to the pond on the property.  When the preserve was privately owned and used as both a weekend retreat and as a farm, the owners maintained a fairly sizable pond fed by four springs.  When NLT acquired the property, the land managers decided to reduce the size of the pond and to begin to accelerate its inevitable transition to freshwater marsh.  (Ponds constructed at the headwaters of small streams are ecologically damaging since they create large expanses of water exposed to the sun.  The water discharged from such ponds is much warmer than water in streams should be, altering the entire ecosystem downstream.)
The pond
The land managers excavated through the berm that was damming the creek and lowered the water level considerably.  This exposed large areas of mud that were quickly colonized by emergent aquatic vegetation.  The remaining pond is only about four feet deep.

Beavers have colonized the pond.  Preston explained that he didn't want beavers in the pond because they were cutting down trees and because they were blocking up the outlet channel and the agri-drain system that NLT installed to allow land managers to manipulate the water level.  He said that he had been in contact with the Pennsylvania Game Commission about removing the beavers.  Kali and I do not believe he made a compelling case for removing the beavers.
A beaver's handiwork at the edge of the pond
Cattails (Typha spp.)
Cattails and green-headed (or cut-leaf) Coneflowers (Rudbeckia laciniata)
A moss-softened path
From the pond, we ventured into a small woodlot where NLT had erected several fenced exclosures to demonstrate the impact of white-tailed deer.  The enclosures were too new to show much difference in vegetation between areas accessible to and protected from deer browsing.
Preserve manager Preston Wilson (light shirt) explaining the deer exclosure
When we emerged from the woods, I found that I had acquired a new arthropod companion on my lower leg.  I gently coaxed the caterpillar onto a Southern arrow-wood (Viburnum dentatum) leaf.
Note the dense auburn hairs plus the much longer, less-dense lighter hairs
The last part of the tour wound through meadows under active afforestation.  NLT plants tree seedlings in plastic tree shelters.  Over the last few years, they have planted nearly 3,100 trees in the preserve in an effort to join woodlots into large blocks of forest.
Afforestation area with an Eastern Bluebird nesting box
Finally, as we neared the end of the walk, we came across a view of this tree (below) sporting a dozen resting vultures.

Botanical Illustration II

I promised I would keep you posted on my progress in my introductory Botanical Illustration class.  During the second class, we tinted the drawing we made during the first class using colored pencils.  One of my fellow students decided not to color her original drawing, explaining that she didn't think the color would enhance the drawing much.  I was inclined to think the same way, but decided to color my drawing anyway (1) to explore the coloring process and (2) because my drawing wasn't a "masterpiece" anyway; so what if I screwed it up?  I'm neither satisfied nor dissatisfied with the result (above).  Kali said that the coloring was pretty subtle, but the colored pencil "leads" were hard - I really had to push to get the color to show.
After we colored our previous week's drawing, we explored drawing on paper tinted with watercolors.  We moistened watercolor paper, dabbed on some color, and encouraged the paint to run and bleed.  The instructor ironed our paper to dry it, then told us to select a spot on which to draw another leaf.  The result appears above.  I'm still not comfortable with the stippling technique; I'm going to have to work on it to achieve the results I'd like.

Tonight: scratchboard.  Stay tuned.

Friday, September 9, 2016

Botancial Illustration

My father had a real talent for drawing; I was always envious of his abilities.  I considered my own talents to be limited.  In fact, I once drew an old grist mill as an illustration to accompany an article I had written for my organization's newsletter, and someone (who did not know that I had drawn the the mill illustration) commented, "I wonder whose kid drew that picture?"  If that wouldn't put the kibosh on any artistic aspirations I don't know what would.

However, since I've inherited half my father's genes, I've often wondered if I could improve my drawing skills with some coaching and practice.  Plus, with retirement looming, Kali questions me constantly about how I'm going to fill my time after I stop working.

So, when a retired high school art teacher offered to teach a three-evening introductory botanical illustration class for my organization, my program planner and I readily agreed to put it on the schedule, and I signed up.  Last evening was our first class.

The instructor asked the students to find a relatively simple leaf as a subject.  Then, we retreated from the oppressive heat and humidity to an air conditioned conference room and set about with plain, old Staples-brand No. 2 pencils to draw the leaf.  The instructor told the students it was perfectly acceptable to trace the leaf, but I decided to try to draw it freehand.  Once we had the basic form and venation on paper, we took fine-pointed markers and inked the outline.  Then, the instructor asked us to highlight features of the leaf in stippling.

My representation of a sourwood leaf (Oxydendrum arboreum) and my subject head this post.  Kali said that she liked my drawing, but didn't think it was a very accurate representation of the subject.  I'm not completely satisfied either (I'm a bit disappointed with the stippling, in particular), but I don't think I've tried to draw anything since my grist mill fiasco.

Next week, we add color with watercolors, and the third week we'll attempt a scratchboard project.  I'll post my results of each.