Pest suppression by natural enemies, a valuable ecosystem service, generally increases with semi-natural habitat in a landscape, but this effect is highly variable. Ecological interactions and processes operate across a wide range of spatiotemporal scales. The success and efficiency of perennial rangeland restoration in California to promote ecosystem services may be increased by targeting efforts at the scale most relevant to the desired service(s). This manipulative experiment examines how the spatial distribution of restored habitat interacts with arthropod foraging and dispersal traits to influence community composition and biocontrol potential throughout a heterogeneous landscape. Epigeal arthropods were sampled with pitfall traps in perennial grass strips that varied independently in proportion seeded and grain of heterogeneity. Individuals were identified to family and morphospecies, assigned a trophic level and functional guild, and body length was measured. Initially, generalized linear mixed effect models were fit to arthropod abundance and morphospecies and family richness as a function of date and 0% or 100% restored treatment. To examine variation in community composition, Bray-Curtis distances were visualized with MDS ordination and grouped by relevant factors. Preliminary results showed arthropod community metrics did not differ significantly between restored and unrestored plots, suggesting: (1) This grassland arthropod community does not perceive these habitats as different, or (2) the processes determining community composition occur at spatial scales not captured with this analysis. Community metrics did vary throughout the growing season: arthropods were smaller and less abundant and diverse as season progressed. These significant trends may be due to decreased resource availability as vegetation senesces in the late season. Further research will examine community differences at larger and smaller scales, relate results to vegetation and resource characteristics, and focus on specific taxonomic and functional groups, especially those with potential to provide arthropod mediated ecosystem services to the surrounding agricultural mosaic.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.