A Race with the Red Queen

No disrespect to the ancients, but the best time to plant a tree was not 20 years ago. It might be this spring.

A variety of leaves from trees planted last fall in Highland Park. Photo by Taiji Nelson.

Whether plant, animal, virus, or bacteria, all living organisms are locked in battle with the pathogens, pests and parasites in their surrounding environment, using the tools and tricks nature’s equipped them with to keep them in the game. One of the strongest tools in this arsenal? The ability to adapt, to one-up opponents in a constant arms race.

One huge task that the Parks Conservancy faces is shoring up this arsenal for the trees in our care. The founders of these fine parks left quite the legacy, not only in the consideration that they gave to the design and experience of the parks, but also the impressive diversity of the urban forests.

It’s tough to overstate the importance of biodiversity to healthy parks. Voracious pests and sneaky diseases gain a slight foothold within the bounds of our parklands and spread like wildfire, faster than we can catch and quarantine them — even with sharp eyes out at all times. Our trees need their natural defenses as they stand on the front lines of these attacks, especially since they face added stresses of living in the city: polluted water, poor air quality, micro-climates, and human intervention.

London plane tree in Schenley Plaza.

A general in this battle, the Parks Conservancy’s Director of Park Management and Maintenance Phil Gruszka is a seasoned veteran. Phil has been rocking war paint for years now. Since conducting a study with Dr. Cynthia Morton of the Carnegie Museum of Natural History, he’s realized that our legacy park trees are impressive in their biodiversity… but that we have to really work to keep it that way. Their study found that tree stock from major nurseries across the country have actually been whittling down the tree gene pool.

“When London plane trees were first introduced to the United States, one nursery had a tree that did very well. But they couldn’t get it to reproduce from seed, so they started getting cuttings to grow out. Then they released it to the trade and named that cultivar ‘Bloodgood.'”

Selected for it’s superior resistance to the fungus anthracnose, the cultivar (a plant chosen for its particular genetic makeup) Bloodgood has been spread around now for about 30 years, dominating nursery stock of London planes. Plane trees bought from nurseries have identical genetic material to every other plane tree — they have not been grown from seed from two parent trees. They’re clones.

“Today, if I wanted to replace a London plane, I can only buy the cultivar Bloodgood.”

But trees from Schenley Plaza and around the park surprised them. “The Schenley Plaza trees were all genetically different, very diverse.” The park trees, planted before Bloodgood started to gain popularity, were much more diverse than the current nursery stock. The surviving 100, of the 200 that were planted years ago, were of a strong and diverse population, toughened from years of fighting off pests and disease.

Then, they widened their net. Was this true only for London planes? How much more diverse are our park trees than trees sold around the country? After polling nurseries from various parts of the country, they found that ten common trees used all over the U.S. were clones — their genetic diversity was actually getting less and less diverse.

Red oaks with oak wilt in Schenley Park, soon to be cleared.

Why has this study been so important? As the Parks Conservancy has taken on ecological restoration projects in the parks over the years and established the Park Tree Action Plan with the City of Pittsburgh, TreeVitalize, and Tree Pittsburgh, we’ve actively worked to increase biodiversity in the parks. Taking cuttings of our own heterogeneous tree stock, we’ve started growing new trees around the park and city in our own sort of diversity study, learning as we go about resistant new cuttings that withstand biological threats. This knowledge gives us only a peek at the immeasurable value of Pittsburgh’s parks; less mature forests and parks elsewhere are markedly more homogeneous, posing a threat to themselves and surrounding forests against the pests and diseases that have shown an uptick in recent years. Our trees are better equipped to keep our parks healthy and beautiful.

This week, a large stand of red oaks — about 50 trees in total — will be cleared from Prospect Drive in Schenley Park. Oak wilt, discovered earlier this year by an observant park user, got a stranglehold on the interlocking root system of the trees, infecting an entire grouping of trees. Left there, the trees are a risk to the health of other park trees. It’s terrible to have to take down so many trees, but it’s something that needs done for the overall well being of the park. And when these trees are replanted in the spring, a variety of new and diverse tree stock will be added to the expanding biodiversity and health of the park.

Wondering about the title of this post? Read more about the Red Queen Effect here.

Recapturing what’s lost: Riverview and Highland Parks

Two more weekends, two more meetings: here’s your last chance this fall to provide input on our Regional Parks Master Plan update.

Riverview Park
Saturday, October 30

The Chapel Shelter is one of the most popular in the city's system.

Riverview Park has a wide expanse of woodland and a maze of trails throughout most of its 287 acres.  Then, in the park’s center, there is a ridgetop where much of the recreational activity is centered.  Between the Chapel Shelter and the Observatory, there is a swimming pool, an unused building called the Bear Pit, the popular Activities Building, and a space-themed playground.  The ridgetop will be the main focus of the meeting’s theme, “Discovering New Destinations.”  Our goal is to reinforce pedestrian connections, improve pedestrian safety, and enhance user amenities in this area.

In addition to thinking about improving access and activities in this area, we’ll also look at the new soccer field on the north end of the park.  We’ll pass by the Centennial Pavilion and discuss potential ways for bringing this shelter back into wider use, as well as whether the area could be improved by the installation of meadows and other stormwater management techniques.   We’ll look at the area where the remnants of Watson’s Cabin stand and discuss potential uses for that site as well.

Highland Park
Saturday, November 6

The original vision for Highland Park was of a seamless connection across the center of the park: a visitor would enter at the magnificent Entry Garden, walk up the steps to Reservoir No. 1, and then walk down another set of steps on the other end of the reservoir (where the present-day PWSA microfiltration plant and babbling brook are located).  The visitor would then walk down another set of steps, reaching Lake Carnegie below.  Then it would be just a short walk to a vantage point with a dramatic view of the Allegheny River and the Highland Park Bridge.

Lake Carnegie is largely unused.

While part of this progression is intact, it’s likely that most people in recent years haven’t used this path through the park, especially since a fenced-off maintenance yard sits between Lake Carnegie and the hillside view.  And while the swimming pool and sand volleyball courts are always lively during the summertime, the once wildly popular Lake Carnegie generally hosts more geese than people on any given day.

The Highland Park master plan update meeting will address these and other issues through the theme “Reclaiming Lost Uses: Lake Carnegie and Beyond.”  We’ll talk about how to restore some of these broken connections, as well as potential uses for other dormant park amenities.  For example, how could the now-empty Reservoir No. 2 (which was closed due to EPA regulations that reservoirs be covered or the water be treated) be used once again?  Is there an opportunity to turn vacant land on Negley Run Boulevard into parkland?

RSVP for one or both of these meetings here.  We appreciate everyone who has provided input so far, and we look forward to hearing from more of you at the upcoming meetings!

People vs. cars in Schenley Park

Schenley Park is home to some tricky intersections.

Our master plan update meeting for Schenley Park this Saturday was a fascinating look at the complex issue of people vs. cars in the park.  There’s no doubt that the park’s layout presents a safety issue in several places, but any solution would have to consider the many different ways that the park is used.  Here are some of the things we discussed at the meeting:

– Can pedestrian and bicycle safety be improved measurably if the solution doesn’t include installing new traffic lights?  How effective are traffic calming measures like speed bumps/humps, bike lanes, and protected crosswalks?
– Are roundabouts a practical consideration for Schenley Park, and if so, what makes a good roundabout?  (Joe Hackett, from LaQuatra Bonci Associates and the master planning team, considers a “good roundabout” to be “a safe haven for pedestrians and cyclists,” not just a way to slow down traffic.)
– Would better connections within the park increase use by cyclists as an alternative to biking on the roads?  (For example, a connection between the Eliza Furnace Trail and the park’s trails could provide an alternative to some road biking for commuters.) 
– Is it possible to balance traffic calming measures with some of the key uses of Schenley Park: i.e., the Pittsburgh Vintage Grand Prix and the Carnegie Mellon buggy races (which happened to be taking place the morning of this meeting)?

After discussing these questions, our attendees walked through the park, assessing conditions from Phipps Conservatory to the Panther Hollow Bridge to Frew Street by CMU.  After witnessing several potential accidents near the Schenley Park Café, it became even more obvious that Schenley Park (with the most roadways cutting through it of any park in our system) has a bit of a car problem.  But there are many ideas on how to solve it…

Success Stories
Several other parks provide case studies that show increased pedestrian and cyclist safety through traffic calming measures.  Brooklyn’s Prospect Park West was a three-lane street where three out of four cars exceeded the speed limit.  This summer, a two-way bike lane, protected by a floating parking lane, was installed to slow traffic and to get cyclists off the sidewalk.  Now, the New York Department of Transportation says that the number of speeding cars has been reduced to one in seven, and only four percent of cyclists are using the sidewalk (down from about 50%).

Crosswalk and speed humps near Temple Gate in London's Hyde Park (click for larger image)

Check out a great video showing the effects of the bike lines in Prospect Park here.  You can also see the DOT’s preliminary data on this page.   

Elsewhere, The Royal Parks has successfully implemented speed humps in London’s Hyde Park to slow traffic.  The bricked humps are low to the ground, designed to slow the speed of cars without damaging them (especially ones that sit low to the ground), and also to be mindful of horse-drawn carriages that use the roads.

South Carriage Drive in Hyde Park (click for larger image)

As you can see from the South Carriage Drive photo, devices have been employed to help signal motorists of how to treat the roadway.  Two painted white arrows just before the pedestrian crossing alert drivers that they are approaching a speed hump, with the thick end of the arrow indicating where the road surface will begin to rise.  At either end of the pedestrian crossing, light poles with orange circular bowls on top flash intermittently, helping improve visibility for motorists at night.  These lights, known as Belisha beacons, indicate crossings where pedestrians have the right of way over traffic.  The beacons are standard to such crossings, ingraining the habit for motorists to stop for pedestrians whenever they see the flashing lights. 

Speed humps have not been without controversy in London, however–emergency services personnel complain that they are an impediment, and they increase the wear and tear on vehicles.  You can read an article on some of the potential objections here.

Lots of food for thought!  Please share your comments and concerns with us below as we continue to gather opinions in preparation for making recommendations.  And don’t forget about this weekend’s Master Plan Update meeting about Riverview Park, where we’ll be discussing how to improve access to the park’s unsung destinations.

Thanks to BikePGH for sharing the Prospect Park information, and to Robert Harbord and The Royal Parks for sending us the London photos!

Finding the balance in Schenley Park

A challenging intersection across from Phipps Conservatory.

Have you ever tried to cross the street in Schenley Park–say, going from the Schenley Park Café to Phipps Conservatory–and almost been mowed down by traffic?  Or is there a spot in the park you always wanted to visit, but you were frustrated by poor trail connections?  Maybe you love walking or biking around Panther Hollow Lake but wish there were an easier way to access the Junction Hollow Trail from there.

The Schenley Park edition of our Regional Parks Master Plan update is designed to address these kinds of issues.  Join us Saturday, October 23, at 9:00am at the Pittsburgh Science and Technology Academy in Oakland (map) for a discussion of connectivity and accessibility in Schenley Park.  We’ll have coffee and pastries on hand to wake you up, and we’ll talk about how to make the busiest park in Pittsburgh even safer.

Then at about 10:30am, we’ll head into the park to look at conditions along the roadways and intersections, in search of a better balance between people and cars.  We need your help to evaluate some of the most important priority spots and suggest opportunities for improvement.  We’d like to make the park safer and more accessible for cyclists, pedestrians, and runners, so we need to hear from those of you who use the park and have faced its current challenges.  The morning will wrap up around 12:30. 

Let us know you’re coming by RSVPing here.

Attendees at the Frick Park meeting visit the observation deck by the Environmental Center.

We had excellent participation at our Frick Park meeting a few weeks ago, where our attendees visited several sites that might one day house outdoor learning spaces.  Participants were able to walk through each site, hear pros and cons, and then rank them.  It’s a great opportunity to get directly involved with what’s happening in your favorite park.  And if you’re not completely sold, just remember this is the peak foliage weekend in Pennsylvania.  If you don’t go to the park, then you’re just missing out!  Hope to see you there bright and early Saturday.

Five Reasons You Should Get Out of Bed and Come to Frick Park on Saturday

Our public meeting for updating the Master Plan for Frick Park is this Saturday, October 2 at 9:00am.  We know the early hour may be deterring you from RSVPing (which you can do here, by the way), but here are five good reasons you don’t want to miss this event:

1. Frick is the largest park in the City of Pittsburgh at 561 acres.  Chances are you’ve used it for something: whether you like to sail down the Blue Slide, learn about butterflies at the Environmental Center, serve aces at the clay tennis courts, or take a peaceful nature walk in Nine Mile Run, there’s probably something you love about it.  But there’s probably also something you’ve noticed that needs some help, whether it’s a lack of connectivity to the Monongahela River on its southern edge or a need for increased stewardship in the natural areas. 

Frick Park needs a plan: we need you to be a part of it.

2. This park has an amazing history.  It all starts with the legend of Helen Clay Frick asking her father for a park where the city’s children could enjoy nature.  But it’s been over 100 years since Helen’s debutante party, and so much has happened in the park since then.  On Saturday, you’ll learn in particular about the fascinating history of the Clayton Hill area of the park, near the Environmental Center.  With a meadow, a woodland, and once upon a time a fountain where people loved to gather, this area has undergone many changes and has incredible potential.  You may gain a whole new appreciation for this part of the park and what it could become.

3. The past ten years have seen dramatic changes…  In 2000, when the original Regional Parks Master Plan was being drafted, the Nine Mile Run stream was virtually lifeless, a waste of a precious resource.  The historic gatehouse at Reynolds Street was crumbling.  Thanks to the efforts of the Nine Mile Run Watershed Association, the stream is now becoming a rich habitat as well as a beautiful park amenity.  The gatehouse has been restored, and trail access in the parks improved.  A tremendous volunteer effort in the parks has resulted in healthier natural areas.  There’s a lot to be proud of.

4. …but the work is far from over.  Not all the changes of the past decade have been good.  The Environmental Center burned unexpectedly in 2002, displacing its staff into two small gatehouses.  Heavy storms, diseases such as oak wilt, and pests such as emerald ash borer are causing problems for the park’s trees.  One of the things we’ll be covering Saturday is the City of Pittsburgh’s recently completed Natural Areas Study, and what it means for developing a woodland maintenance plan.  We’ll also talk about plans for maintaining the park edges (like in the Homewood Cemetery area) and developing a long-term stewardship plan for Nine Mile Run.

With so much accomplished in the last ten years, there’s no reason to think we can’t continue this progress in the next decade.  But it won’t happen unless the people who use the park are engaged in the process of making it better.

5. Frick Park is set to get really educational.  One of the most exciting initiatives from our point of view is the re-visioning of the Environmental Center at Frick Park.  This process is so much more than a new building: it’s expanding educational opportunities throughout the whole park.  You’ve probably heard us talk a little about the idea of outdoor learning spaces.  These will be subtle ways of using what’s already there in the parks to educate kids and families about stormwater, animal habitats, streams, and other things that make up a park.  We’ll be visiting four potential sites on Saturday, so you’ll learn much more about these plans and have a chance to tell us what you think about them.  You can see a preview of some spots we’re considering here.

Oh, and reason 5.5…we’ll feed you!  Come a little early; we’ll have coffee and pastries starting about 8:30.  Please RSVP today–we need as many voices as possible to help us develop future plans for Frick Park, and we want you to have your chance to jump in at the beginning of the planning process.  We hope to see you Saturday!