The community structure of spiders and their prey in the urban ecosystem of Cleveland, OH

Many urban areas experiencing economic decline, such as Cleveland, Ohio, contain large numbers of vacant lots under consideration for environmental restoration or redesign. Spiders are important natural enemies within these greenspaces and may serve as a model system for understanding how urban land use changes influence animal communities and the ecosystem services they provide. Spiders may provide predation services crucial in urban gardening and farming, a service important for the success of growing local food and maintaining sustainable economic practices. Research beginning in June 2011 will measure the composition of spider communities, and their role as natural enemies, within maintained vacant lots, those repurposed as community gardens, and park grasslands serving as biodiversity refugia within the Cleveland metro area. Spiders will be collected using pitfall traps and vacuum samples in order to measure species and hunting guild diversities and abundances. Local site (e.g. floral, grass, mulch area) and landscape (e.g. lawns, trees, pavement, building area) variables will be analyzed to determine their relative influence on spider community composition within the various urban greenspaces. This research will test the applicability of the Modified Intermediate Disturbance Hypothesis in describing the structure of spider communities, which suggests that biodiversity will be highest within intermediately disturbed habitats (vacant lots), but that guild diversity will be highest within infrequently disturbed habitats (grasslands). In this case, spider hunting guild diversity is important for assessing the ability of a greenspace to withstand extinction and maintain predation services.