Bryological and Lichenological Section/ABLS
Opdyke , Matthew R , Dolney, Bryan .
Distribution and diversity of lichen communities influenced by urbanization in southwestern Pennsylvania.
Lichen communities are bioindicators of air pollution and habitat alteration, among other environmental consequences of urbanization. In regions impacted by urbanization a long-term decline in species diversity is often observed. The distribution and diversity of epiphytic lichens was studied in the Pittsburgh region in southwestern Pennsylvania to assess the influence of urbanization. Monitoring plots were established at two urban sites (Frick and Schenley Parks) within the city limits of Pittsburgh and two rural sites (Mingo Creek Park and Roaring Runs Natural Area in Forbes State Forest). At each site,six plot trees were surveyed for percent cover of lichens using a 20x50 cm microplot placed at eight locations on the tree at 0.5 and 1.5 m above the ground in the north, east, west and south directions. Additionally, trees within a 465 m2 plot surrounding the plot tree were searched for lichens and percent cover of foliose, crust and squamulose forms up to 3 m on a trunk was estimated. Urban and rural sites exhibited contrasting communities of epiphytic lichens. A complete site survey of lichens resulted in 43 species of epiphytic lichens found at rural sites and 27 species at urban sites. The lichen diversity value, which is a statistical estimator of environmental conditions of a site, averaged 20.8 and 11.3 at the rural and urban sites,respectively. The higher value at the rural sites suggests that environmental conditions are better for lichen growth. Within the 465 m2 plots,crust lichens had two times the percent cover on red oak, sugar maple and black cherry trees than foliose and squamulose lichens at urban sites. At rural sites,the more abundant lichen form was squamulose. The dominance of nitrophilous and sulfur dioxide tolerant macrolichens at all sites, such as Flavoparmelia caperata, Parmelia sulcata, Phaeophyscia sp. and Physcia sp. suggest that air pollution is widespread throughout southwestern Pennsylvania. Thus, localized differences in moisture availability, intensity of air pollution and habitat alteration most likely result in the epiphytic lichen community to be more diverse and healthy in rural sites compared to urban sites.
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1 - Point Park University, Natural Sciences and Engineering Technology, 201 Wood Street, Pittsburgh, PA, 15222, USA
2 - Pittsburgh Parks Conservancy, Pittsburgh, PA, USA
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM