Mentor: Professor Neal Williams
In recent decades the Philadelphia area has experienced rapid and extensive developmental growth, and development continues to expand into surrounding green areas. In the last ten years alone, what used to be the outer suburbs, interspersed with wooded areas and ringed by agriculture, has seen the quick construction of large housing developments, retail outlets, and the widening of roads to increase traffic capacity. This rapid land conversion could have many ecological consequences, including a negative effect on bumblebee (Bombus spp.) populations. It is the goal of this study to evaluate species composition in different landscape matrices in order to determine the effect development intensity in the surrounding landscape may have on species richness and the presence of particular bumble bee species. The study will take place from the beginning of June to the middle of August 2006 in Philadelphia, Montgomery, Chester, Delaware and Bucks counties in Pennsylvania. Fifteen replicate sites containing meadow and woodland periphery will be chosen from urban, suburban and rural areas within these counties. Each site will be sampled via net collection tri-weekly between June 1 and August 31 (4 total samples) to account for early- and late-emerging species of Bombus and early- and late-blooming species of flowering plants. After collection, the specimens caught will be frozen, pinned, and identified to species. As floral diversity may be a factor in species composition at a given location, I will also conduct a flowering vegetation survey at each site. The extent and intensity of development surrounding these sites will be quantified using landuse data made available by the Delaware Valley Planning Commission in the Geographical Information Systems (GIS) program ArcView 9.1. The results of this spatial anaylsis will then be compared to the species composition found at each site and landscape type as a whole (urban, suburban or rural).
Williams, Paul. 2005. Does specialization explain rarity and decline among British bumblebees? A response to Goulson et al. Biological Conservation 122, 33-43.
Squires, ed., Gregory D. Urban Sprawl: Causes, Consequences and Policy Responses. Urban Institute Press: 2005.