PARENT SESSION
Oral Session # 80: Urban Ecology II: Soils and Streams.
Presiding: J Ehrenfeld
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 105.
Invasibility and dispersal in urban wetlands.
Bowman Cutway, Heather1, 1 Rutgers University, New Brunswick, NJ
ABSTRACT- In urban fragments, the incidence of invasive exotic species is considered common. Urbanized areas are exposed to many factors that are known to increase invasibility including high perimeter to area ratio, anthropogenic influence, and disturbance. This study evaluates the effect of land use on the invasibility of forested wetlands in the highly urbanized Arthur Kill watershed in northeastern New Jersey. The diversity of land use within the urban landscape is usually ignored, causing diverse urban fragments to be lumped together improperly. Through a vegetation survey of 17 forested wetlands of different sizes and surrounding land, I determined that wetlands surrounded by residential land use had a significantly higher richness and density of exotic species than wetlands surrounded by industrial land use. Large residential sites had a surprisingly high number of invaded plots (46.7±8.2%). However, all industrial sites had a relatively low percentage of invaded plots (12.3±6.2%) when compared with small residential sites (52.6±21.9%). Riverine sites proved to be the most invaded with 84.0±18.9% of the plots having at least one exotic species present. Differences in invasibility of these urban forested wetland are likely the result of seed dispersal dynamics. I conducted a series of experiments that examine several components of seed dispersal including a seed trap study that measures current seed flux, a seed bank survey which examines past seed flux and a seed addition experiment that examines germination after dispersal. The information garnered from these experiments will help to build on our current level of understanding regarding the function surrounding land use in determining seed flux and site invasibility.
Key words: dispersal, wetland, invasibility, urban