Williams Lab Research
 

Rosemary Malfi, BMC '07:   The effects of suburban development on bumble bee communities in restored grassland habitats

I am currently exploring the impact of development on bumble bee (Bombus) species diversity and abundance in managed grasslands in southeastern Pennsylvania (Bucks, Chester, Montgomery, Philadelphia and Delaware Counties).  The project combines field surveys of bees and Geographic Information Systems (GIS) datasets to determine surrounding landscape composition including degree of suburban and urban development.  Having carried out ecological research in various forms over the past year and a half, I am certain that I want to attend graduate school to continue my study of Ecology.

 
 

Daniela Miteva, BMC '07: Effect of landcape change and habitat management on native pollinator communities and plant reproduction

Many plants, wild and crops alike, depend on pollinators to set fruit. The availability and efficiency of pollinators can be influenced by the degree of landscape fragmentation and habitat management. I am currently researching how these factors affect the composition and abundance of bees in abandoned agricultural fields in New Jersey. The presence of pollinators in turn may determine successful reproduction of native and invasive plants and have implications for conservation of native species of bees and plants. My study species include 3 plant species introduced from Europe (Linaria vulgaris, Allium vineale and Centaurea nigra) and 1 native North American species (Solidago odora).

        
 

Amanda Rahi,  BMC '07:  The role of specialist and generalist pollinators for reproduction of the desert mallow Sphaeralcea laxa.

I am currently studying plant-insect interactions and plant reproductive biology. For the past two summers I have been comparing the contributions of specialist and generalist pollinators, primarily native bees, to the reproduction of desert mallow Sphaeralcea laxa (Malvaceae). To compare the pollnator effectiveness, I estimate pollen removed from the anthers, measure deposition of pollen onto flowers, quantify pollen tube growth using fluorescence microscopy, record seed set by fowers as a result of single visits by each visitor species.  These estimates are combined with visitaion rates to determine the contributions of different pollinator species.  

                                                
 

Erica A. Smith HC '05  Research Thesis: Brassica napus stigma receptivity:  An examination of dichogamy and herkogamy in hermaphroditic oilseed rape

Brassica. rapa flower illustrating spatial separation between stigma and anther.  At this developmental stage the stigma is exerted and sits atop the elongating style and ovary.