With thousands of trees lost, Pittsburgh fights to preserve and improve its tree canopy

Since then, they’ve been able to obtain enough donor funding to broaden the scope of their work, which includes a currently unpublished study on the red maple. Researchers in other parts of the world have also started looking at diversifying the genetic makeup of urban forests, including some in Australia and in Canada.

Still, more funding is needed to continue their work.

“We received an individual endowment but it’s a drop in the bucket for what we actually need to make an impact on the horticultural community,” says Gruszka. “But we’re so close. We’ve been doing this for going on 11 years and are starting to get some traction.”

Where the wild trees grow

It’s a gray, windy April day along the Allegheny River. Nestled under the 62nd Street bridge, Tree Pittsburgh shows off its growing Lawrenceville facilities. What was once the site of the Tippins Steel Mill is now home to thousands of young trees and a yet unfinished eco-friendly green building and campus that will serve as Tree Pittsburgh’s new offices and as space for its educational programming. It’s set to open this summer.

The event also heralds the expansion of the nonprofit’s new Heritage Tree Nursery, an effort to provide high-quality, genetically diverse trees to partners throughout the region, including the Western Pennsylvania Conservancy, Allegheny Land Trust, and Pittsburgh Parks Conservancy.

Heritage Nursery director Megan Palomo was brought on to help expand the three-year-old riverfront site and, like Gruszka, agrees that “more diverse genetics means there’s a better chance of survival” for trees in Pittsburgh’s urban forests. This means focusing on seedlings as opposed to cloning.

“Growing trees from seedlings is not very common in the conventional nursery practice,” she says, as she shows off trees in various stages of growth throughout the Lawrenceville site, many of which are housed in long, domed hoop houses covered in plastic sheeting. About 400 new trees, many encased in wire cages, bend in the breeze on the nearby river bank.

Unlike conventional nurseries, which provide cloned trees for gardening and ornamental landscapes, Tree Pittsburgh collects seeds from as many different trees as possible throughout Western Pennsylvania. For their heritage nurseries, says Palomo, they visit places like cemeteries and parks and gather seeds from old trees that have succeeded at withstanding challenges like air pollution and extreme temperatures.

Tree Pittsburgh grows more than 90 varieties of trees, including oaks and evergreens, redbuds and buckeyes, as well as paw paw, hackberry and serviceberry. Though they currently grow 10,000 trees a year, Palomo says the organization is not meeting the demands of their partners. She expects that the Lawrenceville site, along with their existing Point Breeze location, will enable them to double their footprint and grow tens of thousands of trees for plantings.

As for the future, Erb says that while they expect to see more losses, they hope to combat it with replanting efforts like TreeVitalize Pittsburgh, a joint project of Tree Pittsburgh, Allegheny County Parks, the City of Pittsburgh and the PA Department of Conservation and Natural Resources. Tree Pittsburgh also hosts free tree giveaways like the one in Market Square last Arbor Day.

In addition to replanting, preserving existing trees is also key. Tree Pittsburgh received a grant from the Pittsburgh Foundation to work with municipalities throughout Allegheny County on improving tree and zoning ordinances so that individual trees and patches of forest can be protected from development. Erb also cites the Mayor Bill Peduto’s executive order last year to create a Task Force on Tree Protection.

“It takes five minutes to cut down a giant oak tree, but it takes that tree 100 years to get big if you replant it,” says Erb. “It’s really critical that we try to preserve as many trees as we can.”