By: Daniel C. Laughlin
Upon arriving at Penn State two years ago, I was immediately informed that prairies graced the Centre Region's limestone valleys prior to European settlement. Strange, I thought, prairies in Penn's Woods? Strange, yet compelling; so I chose to study these prairies to try to answer a few simple yet illusive questions: where were these prairies located, how abundant were they, and what plant species resided in them?
Several eye-witness accounts of a prairie in Penns Valley, called the "Great Plains," are preserved in dusty volumes in the library archives. For example, the traveling Reverend Philip V. Fithian wrote in his diary in 1775, "In the valley there are large open plains, cleared either by Indians or accidental fire. Hundreds of acres are covered with fine grass and a great variety of flowers." The historical accounts tell us, in short, that prairies existed, but they don't shed light on which plants were in them. Fortunately, however, a small remnant prairie chalk-full of prairie plants persists in Penns Valley and several other small prairie communities are scattered throughout central Pennsylvania.
These prairies have many characteristics in common. First, they are all found on south-southwestern slopes in the valleys of the Ridge and Valley Physiographic Province. Second, they are all found on rocky and extremely shallow limestone soils, typically on the Opequon soil series. Hence, they are extremely dry environments where only drought-tolerant plants can persist. Third, they are all extremely small; a total of less than one hectare of limestone prairies remains in Pennsylvania. Finally, they contain many of the same plants and the dominant grass is always sideoats grama (Bouteloua curtipendula). My results indicate that these prairies were never abundant in central Pennsylvania; however, they are unique and did provide valuable habitat for many prairie plants and animals, including bison and elk. These rare communities have almost been eradicated from the Pennsylvanian landscape and they continue to shrink in size due to woody plant invasion.
But The Arboretum at Penn State is trying to reverse this trend. Last summer, I initiated a modest native prairie planting within the future site of the Arboretum. The planting is located on high and dry ground on a shallow limestone soil that is very similar to the soils in the prairie remnants. I collected seeds from over 20 native prairie plants from local prairie remnants. After germinating the seeds in the Forest Resource Laboratory greenhouse, Matt McMahon and I planted the seedlings in the first week of June 2001. Examples of native prairie species in this planting include sideoats grama, prairie brome (Bromus kalmii), long-headed anemone (Anemone cylindrica), rigid goldenrod (Solidago rigida), whorled rosinweed (Silphium trifoliatum), wild bergamot (Monarda fistulosa), and butterflyweed (Asclepias tuberosa), a few of which are listed as threatened or endangered in Pennsylvania. The plants thrived the first season and a few flowers bloomed, but this season promises a stunning display of vibrant prairie color and texture.
The prairies in Pennsylvania are not just ecological anomalies. They are historical, cultural, and ecological reminders of a time when natural processes created a mosaic of habitats throughout central Appalachia. To my knowledge, this planting represents the first-ever effort toward limestone prairie restoration in central Pennsylvania. As the Arboretum evolves into a national attraction, plans are to develop this initial planting into a restored prairie community. As the prairie planting grows, and as the restoration of native landscapes within the Arboretum burgeons, we will gain a deeper understanding of the priceless natural heritage that once thrived in our own backyards.