Old-growth tract in Arboretum to receive special attention

University Park, Pa. -- Most of the trees growing on land that is now the Arboretum at Penn State were cut and turned into charcoal to feed the Centre Furnace iron-making operation between 1792 and 1858. But one tract of about 42 acres, adjacent to what is now State College's Sunset Park, escaped the loggers' blades and now is receiving special attention.

Forestry experts in the university's College of Agricultural Sciences are developing a plan to conserve the parcel and its old-growth trees, remove invasive plants and dirt-bike trails and ramps, and use the project as an educational model for students, the local community and arboretum visitors.

After iron production ceased, the cutover lands around State College were cleared for agriculture, resulting in vast farm fields surrounding the city. But the woodlot remained, now presenting what arboretum director Kim Steiner calls an educational and conservation opportunity.

"A graduate student working for the arboretum searched historic records and learned that the woodlot was not cut because the Centre Furnace operator was not able to convince the original owner, James Hartley, or subsequent owners, to sell it," said Steiner. "Now known as the Hartley Wood, the tract is unique in this region, and another graduate student is developing a management plan tailor-made to preserve it."

That student, Samuel Grinstead of Bowling Green, Ky., has taken a comprehensive inventory of the woodlot as part of a yearlong study. This study ultimately will provide information and recommendations to bring the exotic species under control and set the woodlot on a solid course toward renewal. In March 2007, a group of volunteers called the Arboretum Woodland Restoration Corps was organized to help implement the resulting management plan.

"The stand is a remnant of the typical valley-floor oak and pine forest that grew here before Europeans arrived," said Grinstead, who is pursuing a master's degree in forest resources. "Seventy-five percent of the woodlot's larger trees are oaks, some of which are more than 300 years old."

The woodlot has an ecological importance to the arboretum, said Steiner, professor of forest biology. "As one of the few mature forests in this region, it contains native woodland herbs and ferns that cannot grow without the soil conditions and the shelter of the tall oaks," he explains. "For thousands of years, the hardwood trees, the rich, calcareous soil and a rock outcrop on the northwestern edge of the lot have provided homes for a variety of plants, each in their niche in the native ecosystem.

"We are extremely fortunate to have this woodlot on the arboretum property," Steiner adds. "It has escaped complete destruction -- and perhaps even partial cutting -- since the arrival of the first settlers to this area, and that is very unusual for this kind of forest."

Grinstead has mapped trails and features throughout the woodlot, including the 12.5 acres owned by the borough of State College. His inventory of the vegetation includes a very detailed record of the size, age and condition of overstory trees. According to his calculations, there are 1,009 trees of more than 15 inches in diameter (at breast height, 4.5 feet) on the University-owned section of the Hartley Wood.

Grinstead has "cored" 200 trees to determine their ages and examined the cross-section of a massive white oak that died in 2000. The slice revealed that the tree had germinated in approximately 1673.

Grinstead's assessment of today's conditions indicates that exotic shrubs, such as multiflora rose, bush honeysuckle, privet and garlic mustard, have become prevalent and troublesome in the Hartley Wood and should be removed. "We need to educate people about the ecologically destructive potential of invasive plants," he said. "Unfortunately, some of the traits that make exotics good ornamental plants also make them good invaders of native habitats."

Anyone who would like to volunteer to work in the Hartley Wood should contact the Arboretum Woodland Restoration Corps at kkr1@psu.edu or (814) 865-9118.

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Last Updated March 19, 2009