Urban arthropods respond variably to changes in landscape context and spatial scale

Abstract

Urbanization and urban landscape diversity influence arthropods, but the influence of landscape factors differs based on arthropod life history strategies and the spatial scale of the analysis. Most research on landscape factors has focused on one arthropod taxon or functional group, yet assessing how changes in urban landscape intensification and diversity affect several taxa across a region can inform biodiversity conservation and landscape management in times of biodiversity loss. We examined the influence of changes in urban landscape intensification and diversity across six spatial scales, from 200mto 5 km, on the abundance and taxonomic richness of five arthropod groups in urban community gardens: Ants, bees, ladybeetles, parasitoids, and spiders. We collected data over three years in 19 community gardens in the California central coast. We determined the influence of urban intensification (percent urban land-use cover) and landscape diversity (number and evenness of land-use types) on arthropod abundance and richness at each spatial scale in the context of local garden habitat. We found that all arthropod groups are influenced by landscape factors, but that landscape influence differed depending on spatial scale as well as local habitat features, likely due to arthropod community interactions and life history strategies. This study is an example of how patterns of arthropod biodiversity in urban gardens are driven by urbanization processes that shape the degree of landscape intensity and landscape diversity across spatial scales.