Protecting the past for the future: Pink Hill preservation project commences
By Laura McPhail
When you emerge from the tree-lined trail at the top of Pink Hill, perhaps slightly out of breath from climbing the slight incline from Painter Road, you might take a look around and wonder why this area is so special. Maybe you came during that short, almost magical, period of time when the pink phlox for which the area is named is in full bloom. Perhaps you decided to explore the Pink Hill Trail and found yourself taking a breather at the bench at the top of the hill. No matter what your reason for visiting, you may not realize that you are standing at the edge of a rare ecosystem whose beginnings can be traced back to over half a billion years ago.
When two large land masses collided millions of years ago, the serpentine layer that had been the sea floor between the continents was buried in rocky hills and mountains. After 100 million years of slow erosion, the serpentine layer was exposed, creating a rare ecosystem with truly unique soil chemistry. Few visitors to the serpentine barren know this complex and fascinating history, and even fewer know that this serpentine barren is the last of its kind in Delaware County. Most don’t know it is home to an extraordinarily diverse group of plants and animals for such a small area of land, including several rare, threatened and endangered species.
“Pink Hill is truly an extraordinary place. The serpentine barrens ecosystem has much more in common with Midwest grasslands than with the forest vegetation that prevails here in the East,” said Dr. Roger Latham, ecologist and conservation biologist. “Pink Hill is home to a fantastically
diverse group of plants and animals for such a small area of land, including at least a dozen endangered or threatened species.”
One such species was confirmed in the early 1990s by Dr. Al Wheeler, Jr, who discovered the rare mirid (plant bug) Polymerus tinctipes, a specialist feeder of moss phlox at Pink Hill. At least 47 rare butterfly and moth species inhabit Pennsylvania serpentine barrens. Scientists expect to find many more kinds of rare animals as more species groups and more serpentine barrens sites are surveyed.
What was once nearly 14 acres of open grassland, the 3-acre area currently known as Pink Hill has dwindled over the decades due to reforestation. “Even though the serpentine barrens plants are adapted to the harsh conditions, the soil chemistry by itself is not enough to sustain them in the long term. They depend on periodic disturbance to prevent replacement by forests,” said Latham in his 2008 report regarding Pink Hill.
Latham noted, “Arguably, all of the still-intact sites that have a chance at longterm viability are globally significant, including Pink Hill. In the past few years, considerable progress has been made to begin the process of ecological restoration, but much still needs to be done before Pink Hill will recoup its losses. With strategically targeted effort, this significant piece of the region’s natural heritage can be brought back to top condition and its
key processes restored to ensure its long-term sustainability.”
So what is the plan for preserving this ecological treasure? First, with the sensitive nature of this project, Tyler continues to work under the guidance of Dr. Latham and Bill Lucas, primary engineer for the project. Meanwhile, Tyler secured several grants totaling $330,000 to fund the restoration project that includes Latham’s recommendations: a prescribed burn, invasive species control, partial soil organic matter removal, selective tree removal, baseline surveys focusing on rare plant and animal species, species reintroduction/augmentation and deer management.
Engineering and stormwater management plans have been completed. Lucas helped guide Tyler through the Department of Environmental Protection’s (DEP) incredibly complex soil and water conservation permitting process. With that permit now in hand, plans for the next steps are in motion.
“So far, we have laid out the fence line, marked out trees that will need to be removed for the deer exclusion fence and roped off trees that will be saved in the barren area,” said Director of Horticulture and project lead Mike Karkowski. Nearly eight acres of woods will be cleared out. However, he is quick to add that the whole project is not simply about “removal.” The staff has been very successful in its first round of collecting seed from several of the rare species that will need to be reintroduced after the initial conservation activities.
The funds granted by the state require a contract, and this contract is not projected to go into effect until February 2015, when the work will go out to bid. This will likely mean that major work at Pink Hill will not commence until the drier summer months. Plans for a controlled burn are underway for spring 2015, but this step is dependent on weather conditions in mid- to late-April. The area to be restored to barren and the corresponding fence line will be cleared at the same time, so the fencing would be installed shortly after the clearing. The fence will be similar to the deer exclusion fence around Tyler’s core area; the fence will include pedestrian gates so the hiking trails that transverse that area still have access to Pink Hill.
“The plans also call for signage and benches in the area, an observation dig to look at the geology of the site and ADA-accessible parking and access to the top of the barren. The trees that are removed from the site will be recycled for other uses,” said Karkowski.
On the surface, the work proposed for Pink Hill may seem counter-intuitive to the layperson interested in conservation. However, a great deal of public education such as tours, lectures and interviews conducted by Latham have provided a significant amount of local excitement about the project and the ecosystem as a whole.
Delaware County used to have the second-highest number of serpentine barrens of any county in the eastern United States. But of the ten serpentine barrens sites that once existed in the county, all have been lost to development or neglect–except for Pink Hill. With a careful and deliberate strategy in place, Tyler Arboretum will continue its mission of stewardship of natural spaces with diligent preservation efforts of this extraordinary area.
“Tyler Arboretum inherited an incredible treasure. I’m thrilled and proud that the Arboretum board and staff, spearheaded by Rick Colbert, took on the enormous challenges of restoring what’s been inadvertently lost and ensuring that this priceless piece of our natural heritage is still here for future generations to enjoy and learn from,” said Latham.
If you would like to learn more about Pink Hill and serpentine barrens, read Dr. Latham’s 2008 report, Pink Hill Serpentine Barrens Restoration and Management Plan.