introduction - Pennsylvania Natural Heritage Program

BLOOM TOWNSHIPThe northeastern portion of Bloom Township is predominantly contiguous forest, and falls within theAnderson Creek – Montgomery Creek LCA. In the southeast corner of the township and also within theLCA, Bilger Rocks is an important biological diversity feature and is designated as a BDA. Outside ofthe LCA, the landscape is less forested and more fragmented, with no core forest habitat except along theheadwaters of Bell Run. Water quality problems pose a significant challenge to the ecological health ofthe township; many of the streams within the township, including Anderson Creek, Little AndersonCreek, and Irvin Branch, are classified as impaired by DEP due to pollution from mine drainage andgrazing. The township’s most pressing conservation needs are stewardship of the contiguity and health ofthe forest ecoystem in the Anderson Creek – Montgomery Creek LCA (see pg. 33), and water qualityremediation efforts.Bilger Rocks BDADescriptionBilger Rocks is a sandstone outcrop formation that hosts a population of the Appalachiangametophyte fern (Vittaria appalachiana). This species is an ancient and unique relict from a pastclimatic era, and its unusual characteristics provide insight into the development of the present-dayclimate and flora. The plant and animal assemblage living in this habitat is a unique community,termed an acidic cliff community (following Smith 1991, as there is no correspondent type listed inthe more recent Fike 1999 classification).Threats and StressesBecause Bilger Rocks is a popular, publicly accessible site, the rock formations receive heavy foottraffic. Although foot traffic has damaged vegetation in many areas of the rocks, the Appalachiangametophyte populations may be somewhat protected by their tendency to grow deep within the rockformation in inaccessible areas. As the Appalachian gametophyte lives only in very protectedenvironments within rockhouse formations, it is likely to be very sensitive to any change in themicroclimatic conditions, especially any decrease in moisture levels, or increased exposure to windand temperature variation.RecommendationsThe fern’s safety might be enhanced through signs informing visitors of its presence and describingits habitat and unique characteristics. In order to maintain the microclimate conditions needed by thefern within the rock formation, forest cover surrounding the rocks should remain intact.50