Spider assemblages within greenspaces of a deindustrialized urban landscape

Many Midwestern cities in the United States have experienced high levels of economic decline and population loss. This deindustrialization has led to thousands of acres of vacant land maintained as grassy habitats. The communities living within these neighborhoods have conceptualized reutilization strategies for this land, including urban agriculture and the creation of small parks of native plantings. In this 2-year study, we examined the impacts of vacant land conversion on spiders within residential vacant lots, community gardens, and planted prairies within the peri-urban park system. At the time of the study, planted prairies on previously vacant land were not common, so those within the park system may serve as a foundation for future plantings. We found that maintained vacant lots contained the most numerous spider assemblages, which was dominated by disturbance-tolerant habitat generalist species. Community gardens contained numerically fewer spiders but a slightly richer assemblage than vacant lots. Similarly low numbers were also found in planted prairies but the assemblage was the most diverse of the greenspaces examined. We also contrasted results at the family versus genus level in order to assess the taxonomic sufficiency relevant for future studies, and found that genus level was important for elucidating the effects of urban land use on these spider assemblages. From this research, we conclude that spiders are an important indicator group of disturbance when examining urban greenspace management and revitalization, and that alteration in greenspace design will influence biodiversity and assemblage composition.