Epigeal fauna of urban food production sites show no obvious relationships with soil characteristics or site area

Urban food production is a growing area of interest as a way of increasing food security, social capital and biodiversity. As food production relies upon ecosystem services provided by invertebrates (e.g. decomposition), it is important to understand the underlying factors affecting their distribution. Here we investigated the influence of soil characteristics and patch area on the abundance and diversity of epigeal invertebrates. Seventeen sites of different size from in and around Leeds, UK, were selected from an open source database on urban food production. Pitfall traps were placed along transects to collect beetles, springtails, and spiders. These invertebrates were identified and counted, adjusting total counts for the number of traps used at each location. Soil samples from the trap locations were homogenized, dried, and analysed to measure organic carbon content, moisture content, and pH, while productivity was assessed by growing radish Raphanus sativus on the soils under uniform conditions. This study found no evidence of correlation of epigeal abundance and diversity with site area or soil characteristics. These findings suggest that there is no evidence as yet of urban food production sites that are too small to be able to draw upon ecosystem services delivered by epigeal invertebrates.