How Philly is Trying to Restore Its Forests

Three of Philadelphia’s forest ecosystems, in Cobbs Creek, Pennypack and the Wissahickon, might just get a little greener.

As part of the Parkland Forest Management Framework, released in April 2013 by the Urban Forestry and Ecosystem Management Division (a subset of Parks and Recreation), there is an ongoing and experimental process underway to restore parts of the city’s natural forestry.

A healthier forest ecosystem provides invaluable and systemic benefits to the city and its citizens, such as improved water quality, temperature modification and air pollution reduction. As for the impact of improved forests on nearby properties, the Framework estimates a 10 percent increase, or $4 million gain, in value as the forest canopy increases.

There are a bevy economic and natural benefits to healthy forests, but Philadelphia won’t see those benefits until we fix our woodlands. So what’s wrong with them? A lot, according to Joan Blaustein, director of the Urban Forestry and Ecosystem Management Division.

“Things are getting hotter and wetter,” said Blaustein, who voiced concern over the lack of available information in how urban forest landscapes are affected by things like climate change and urban expansion.  “We decided we weren’t going to continue to restore the way we had in the past — restoring historic landscapes. We didn’t have the funding to do that anymore.”

In one way or another, all of this damage is due to human activity. Some of the Urban Forestry’s largest concerns include the rising population of white tail deer and invasive vines like honeysuckle, wild roses and privet, which form dense masses around trees, essentially suffocating them.

It’s a strange chain reaction, Blaustein said. Urban expansion has forced deer into condensed areas, which, in turn, spikes reproduction. The ever-increasing population of deer wipe out low-growing native species in our forest ecosystems. This leaves an opening for invasive plants to butt in and squeeze out the native vegetation.

“A lot of [invasive plants] migrated from people’s gardens or yards,” Blaustein said. “The seeds get carried along, and when there’s an opening — they dig in vigorously.”

Multi-Pronged Plan to Save Philadelphia’s Forests

The experimental restoration that Urban Forestry has planned for Philadelphia’s urban forests offers a multi-pronged attack plan.

First, deer fence will be placed around the forests, containing about 30 acres in each park.

“It’s very, very difficult to get regeneration when you have deer around,” said Blaustein.

The fencing will go up at the end of May. Then, the areas will be cleared of invasive species causing destruction, which requires an incredible amount of management.

“The clearing work we have in Cobbs Creek and the Wissahickon is ongoing now,” said Blaustein, adding “we expect to finish up clearing work in the next month or so.”

This coming summer, Blaustein’s division will go through each area and treat resilient invasives with herbicide. Then, in the fall, planting and reintegration of native species will begin.

The completion date? Well, there is none.

“We don’t have a long-term plan,” said Blaustein. “There’s no endpoint because we’re not sure what the results are going to be.”

As time goes on, Blaustein and her small staff of five will be monitoring and adapting the process in an attempt to create the most sustainable and resilient program possible — on a relatively miniscule budget. The first phase for the initial three sites (90 acres total) has been allocated $500,000 for preliminary clearing and the erection of deer fencing. An additional $100,000 has been budgeted for plant material.

“Because this is an experiment, we want to test a variety of things and see how they work, then adapt our management techniques to the results,” Blaustein said.

The heavy work will be carried out by contractors, but the Urban Forestry and Ecosystem Management Division needs help from the community.

“We don’t have the capacity to do this,” she said.

Given the critical level of importance in monitoring these areas over an elongated period of time, the division has begun enlisting the help of citizens, particularly in the Cobbs Creek area, which has sustained substantial damage.

“We’ve actually run a series of classes on basic land management and experimental design so that those folks will better understand what we’re doing and be able to help with monitoring,” Blaustein said.

Those volunteers will be, more or less, the division’s eyes and ears. Still, they need more help. Centuries of settlement, urban development, industry, logging and agriculture have monumentally impacted Philadelphia’s forest resources, triggering multi-system imbalances.

“Urban areas where people can continue to live are the ones that have clean water, moderate air temperature, not an excess of carbon,” Blaustein said. “Even if people never go to visit these forests or walk the trails, they’re right now getting the direct benefit. That benefit will become more crucial as the planet gets warmer.”

 Image via Flickr user Pauline Rosenberg