Land use change affects spider community structure in the urban ecosystem of Cleveland, Ohio

The city of Cleveland, OH, has over 3,300 acres of vacant land under consideration for a variety of urban revitalization efforts. These include urban garden development, park creation, and natural refuges for wildlife. Land use and management affects a variety of ecosystem services, including those provided by arthropods such as pest control. Spiders are important generalist predators and are among the first predatory arthropods to enter traditional agricultural fields following disturbance. Therefore, spiders may serve as a model system for understanding the influence of urban land use change on arthropods. We compared the spider communities supported within current vacant lands with two habitats which could be established on vacant land holdings: community gardens and park grasslands representative of grassland conversion sites. Collections were made monthly in June-August, 2011, from each habitat to measure the response of spiders to urban land use change.

Spiders were sampled using pitfall traps and vacuum sampling from standing vegetation. Pitfall data indicated that spider family diversity remained relatively high and stable in the grasslands, but diversity declined in vacant lots and gardens throughout the summer. In June, spiders were equally abundant in the grasslands and vacant lots, but abundance in the grasslands decreased throughout the sampling period. Spiders collected in gardens were overall least abundant and diverse throughout the summer. Wolf spiders (Lycosidae) and sheet-web weavers (Linyphiidae) dominated the catches in pitfall traps, but analysis of spiders collected by vacuums is expected to reveal additional important family composition. Collections will be repeated in summer 2012.