The serpentine barrens are unique ecological niches in North America, many of which are located on the Maryland/Pennsylvania border along the Mason Dixon Line. These areas contain grasslands and savanna ecosystems with rare and endangered flora and fauna that have interested botanists, biogeographers, geologists, plant physiologists, and nature enthusiasts since John Bartram, Benjamin Franklin, and John Fothergill, M.D. (Alexander 2009; Dann 1988; Pennell 1930). Since the European settlement of the North American continent in the 1750’s, the barrens have remained relatively stable. However in the past 50 years natural fires have been suppressed, grazing and logging have ceased, and the advent of developments such as shopping centers, golf courses and suburban housing further threaten these sensitive sites (Latham 1993, Tyndall 1992a). Trees and invasive woody plants have subsequently encroached upon the grasslands and savannas; the reduction in open serpentine areas is evident through comparisons of historical aerial photographs to current ones (Latham 2008, Tyndall 1992a). The current methodology was to compare the sizes of local Pennsylvania serpentine barrens grasslands from historic and current photographs and maps and compare historic and current lists of endemic and known serpentine flora data. I hypothesized that the number of flora endemic and known to serpentine areas decreases with the reduction in size of open grasslands and savannas. My review of the current and historic plant lists and literature indicate that northeastern temperate grasslands and savannas are decreasing in size or disappearing, and the result is a reduction in serpentine barrens biodiversity.
Rengert, K. (2015). Historical trends in size and endemic species for serpentine barrens in Pennsylvania. , 1-48. Retrieved from https://digitalcommons.wcupa.edu/geog_stuwork/1