Direct and indirect effects of island size and wave exposure on shoreline arthropod diversity

Aim: Available theories suggest that the species number increases with island size, but the relationship between island size and species density, the number of species per unit area, is less understood. Moreover, mechanisms connecting island size and species density are not always evident because small and large islands differ in physical characteristics other than island size. The purpose here was to disentangle direct and indirect effects of island size and wave exposure on the species density of arthropods from herb-dominated shore habitats.

Location: Islands in the Stockholm Archipelago, Sweden

Taxon: Spiders (Araneae) and beetles (Coleoptera)

Methods: We collected spiders and beetles on vegetated shores on islands of varying sizes, and used structural equation models to disentangle direct and indirect island size and wave exposure effects on species density.

Results: Island size affected diversity of web-building spiders, predatory beetles and other beetles (detritivore...