My first major field site is live! Earlier this month, I deployed nearly 200 low-cost AudioMoth recorders in Sproul State Forest. Located in north-central Pennsylvania, Sproul is 300,000 acres of mixed-oak forest whose long history of human disturbance makes it an especially exciting field site for my research on the controls of species distributions in mixed landscapes.
Sproul is one of the oldest state forests in the Pennsylvania and was founded in response to the rapid deforestation and industrialization of the late 19th century. Before the arrival of European settlers, more than nine out of every ten acres in Pennsylvania was covered in forest. Native peoples used prescribed burning to clear undergrowth and cleared tracts of trees for farming, but kept ecosystems in equilibrium; with these methods, the forest was virtually an endless resource. But the arrival of colonialism led to rapid overexploitation and within a few hundred years, forests that had thrived for millennia were depleted. By 1860, Pennsylvania led the nation in timber production, but four decades later, Pennsylvanians actually had to import their wood.
By the end of the 19th century, two-thirds of Pennsylvania's forests had been cleared for timber, agriculture, and industrialization, and nearly all of the remaining forests were held by private interests. The mostly bald, dry countryside was highly susceptible to wildfires (which were often ignited by railroad sparks), and the lack of erosion control led to heavily polluted streams. Conservationists began speaking out in favor of protecting land and allowing the forests to regrow, and the state government began purchasing large tracts of land. In those first decades, hundreds of millions of seedlings were planted on Pennsylvania's public lands.
State Forests, like National Forests, are working forests, which means they are actively managed for timber and mineral resources. Many areas are protected for their ecological, historical, and/or aesthetic value, providing abundant opportunity for residents and tourists to engage in low-density outdoor recreation. State game lands help balance ecosystems by controlling deer populations and preventing overgrazing in the absence of historical predators. State foresters make management decisions informed by a multitude of long-term research and monitoring projects. Thanks to these more sustainable management practices, Pennsylvania now boasts 60% forest cover while still leading the nation in hardwood production.
In early October, the foliage was just beginning to turn. An unusually thick, branched birch grows out of the thick shrub layer. Heath shrubs like mountain laurel and various Rubus species grow abundantly on the acidic, sandy ridges of Pennsylvania. Notably, many trees in Sproul exhibit spectacular lichen and moss coverage.
This long history of human influence makes for a highly disturbed deciduous forest right along one of North America's major flyways. Migratory birds take advantage of warm updrafts created by the long, continuous scarp of the Allegheny Front (which is just a few miles from my recorders). The study site runs through thick secondary forest, steep mountainsides, deer exclosures, recreational areas, some utility right-of-ways, and several natural gas well pads.
My job as a scientist is to look at such a disturbed, yet lively landscape, and wonder: where are species found and why do they congregate there? And how would scaling (changing the size of the habitat) affect those species? If a wildfire or development cleared a fraction of the forest, which species would be at risk of extinction?
These questions are some of the greatest challenges facing land managers in the age of climate change. I hope for this research to provide more insight into these problems, so conservation managers can make informed decisions that preserve biodiversity for generations to come.