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July 7, 2005

Pitt at Pymatuning: It’s a different University

Peter Quinby intently looks at a log.

This is not your garden-variety piece of wood, but a fallen willow encrusted with moss and a mass of rust- and yolk-colored fungus.

According to Quinby, director of Pitt’s Pymatuning Laboratory of Ecology, this fallen giant is evidence of mature woods changing into an old-growth forest, something that is characterized by some very old trees, many of them over 100 years old.

He checks over the willow and inspects one of his nearby survey plots in Wallace Woods. Quinby gets excited when he spots an oak sapling. “This is a good sign,” he says, referencing the work of Walter Carson, another Pitt biologist at the lab, who is studying the steep decline of oak and other trees. “The deer eat them,” Quinby says of the saplings. He wonders aloud how much the deer graze in Wallace Woods. Finding those kinds of answers are what he and other researchers hope to learn in their field research.

Quinby and Carson are among more than a dozen researchers and graduate students spending at least part of their summer at the Pitt lab examining a wide range of ecological issues such as how forests grow, how songbirds communicate and how pesticides kill tadpoles.

Nestled on the shores of Pymatuning Reservoir in the northwest corner of the state, the Pymatuning lab is the largest year-round biological field station in the northeastern U.S, capable of housing almost 130 people.

It’s the kind of place where a great blue heron will leave footprints in the sand volleyball court at the lab’s housing site overlooking the lake or where students sit around a campfire at night. It’s not your typical classroom, although the Pymatuning lab has traditional facilities such as lecture rooms, offices, labs and housing. The research and classes conducted there focus on the outdoor environment.

Faculty and students have access to 30,000 acres of wildlife habitat including lakes, forests, wetlands, rivers, streams and fields. Some of the research being conducted at Pymatuning lab includes:

• William Searcy, Maytag professor of ornithology at the University of Miami; Steve Nowicki, Bass fellow and professor in the departments of biology, psychology and neurobiology and dean of natural sciences at Duke University, and Melissa Hughes, assistant professor at the College of Charleston, are studying the mating behavior of birds with a focus on how birds communicate through song.

• Carson and Tia-Lynn Ashman, both Pitt associate professors of biology, are studying plant ecology and evolution. Ashman is focusing on the interaction of plants and their pollinators. Carson is examining the roles of competition in shaping plant communities. He wants to learn why oak forests are not regenerating and is looking at a number of explanations including the impact of deer grazing.

• Rick Relyea, Pitt assistant professor of biology, and Andrew Turner, associate professor at Clarion University, are researching predator-prey interactions in aquatic ecosystems. Relyea also is examining the impacts of pesticides on aquatic communities and amphibians.

“We couldn’t do this kind of work in Oakland. This takes acres of land,” Relyea said while standing in a field lined with hundreds of artificial ponds designed to test the survival of amphibians, particularly when they are exposed to pesticides.

He uses aqua plastic wading pools and cattle watering tanks to create his pond environment for tadpoles and other aquatic life. Most ponds are lined with decomposing leaves to create food for his subjects. He procures predators such as dragonflies and red-spotted newts locally to see how amphibians react to stress, especially in the presence of a pesticide.

While Relyea is creating ponds and environments for amphibians, Carson studies what already exists in nearby Tryon-Weber Woods, a small, pristine old-growth forest tract owned by the Western Pennsylvania Conservancy.

Two things will have a major impact on the forest, Carson explained. The first: “The forest is being heavily over-browsed by the deer.” The second: Beech bark disease is expected to hit the forest. When it does, the adult beech trees will die as they have been doing in the Allegheny National Forest, he said. Carson erected six fences to keep deer out so he could study what grows in the forest understory. His findings: Grazing deer, coupled with the impending beech bark disease, which he has observed elsewhere in the state, “will result in a low-diversity forest.”

Carson’s research at the lab as well at the Allegheny National Forest and other sites has yielded some unnerving news about Pennsylvania forests: “The diversity in species of trees will decrease by half throughout the state in the next 50 years,” Carson said. “It’s too late to do anything about it. It’s a done deal.”

Carson blames the Pennsylvania Game Commission’s “gross negligence” for allowing deer populations to grow three to seven times higher than what nature can support. The game commission regulates the deer population, in part, by conservation practices and hunting policies.

Undergraduate students enrolled at the Pymatuning lab have participated in much of Carson’s forest research. For example, every summer he takes a class from Pymatuning to study the Allegheny National Forest’s growth. “Those classes have collected data that have led to two research papers in the last three years that have helped to demonstrate the intense deer overbrowsing that occurs. And those undergraduate students have been first authors on both papers.”

Carson credits the Pymatuning lab for providing “immersion and instant access for students to natural environments and cutting-edge experts in the field — it’s an ideal educational environment.”

In another forest in nearby Wallace Woods, a 26-acre tract owned by the University, Quinby has designated 50 plots, with a 15-meter radius, to study how the land changes: What flourishes? What doesn’t? What needs more light? How is the understory growing?

“One of the main reasons we’ve established this is to get a better understanding of how natural ecosystems work and learn how humans are degrading our forests,” Quinby explained.

He’s trying to create a baseline of what plant life should be expected in an area like this. So far, he’s recorded 152 varieties of plants in this extremely diverse habitat. The variety begins with the different types of soil: Sandy soil near the creek gives way to more loamy soil upland. “This habitat diversity supports more species diversity,” Quinby explained.

As evidence, Quinby walks past a small stand of trees and easily identifies seven species: Sumac, beech, sugar maple, red maple, black cherry, hemlock and elm.

“We’re lucky we have this area to study,” Quinby said. He looks at a tall, healthy oak tree, and notes, “Two 8-foot sections of that could bring in a couple thousand dollars in the market.” Such trees in the hands of a private owner might not exist.

He points to a yellow birch, with its thin, outer layer of bark like peeling paper, exposing another layer of bark that is shiny and yellow with bronze and gold tints. “This tree is a typical component of the northern hardwood forest,” he noted, adding that Wallace Woods is in the most southwestern part of the range of northern hardwood forests.

Quinby paused by a red maple that is 200-250 years old, noting that there isn’t much of an understory beneath the tree. Seedlings and saplings as well as other vegetation are sparse because the foliage of such a massive tree blocks the sun, minimizing the growth of other plants. As the largest tree in the stand, he said, the red maple can help determine how old the forest is.

The study of Wallace Woods might yield information that can be applied elsewhere, according to Quinby. “If we wanted to determine what the best method of logging would be for a northern hardwood forest, we could use these woods as a benchmark for comparison,” he said. Also, if someone was restoring a northern hardwood forest, Wallace Woods could provide an example of the appropriate combinations and concentrations of trees and plants, Quinby added.

He would like to see the Pymatuning lab researchers tackling more local environmental concerns such as the overabundance of geese and carp. For example, the lab was asked by the Pennsylvania Department of Health to submit a proposal to determine the human pathogens that are in geese droppings. “Geese are contaminating the water and it is a risk to human health,” he explained. In 2004, Pymatuning beaches were closed about 10 times to swimmers because of unhealthy concentrations of E. coli, most likely caused by geese droppings. More research needs to done to fully explore the water problems and its causes, Quinby said.

“The lab wants to be poised to become a significant player in terms of scientific research that will contribute to solving local resource management issues,” he added.

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