Litter arthropods display greater differences among locations than grass species in a temperate grassland

Grasslands comprise a significant portion of terrestrial ecosystems, contributing an estimated 20% of global carbon stores. Biomass is recycled in these systems by photodegradation, biotic decomposition, and through disturbances such as fire or grazing. Yet the role of the arthropod community in biotic decomposition remains unclear in many grasslands worldwide. To help close this knowledge gap we conducted a litter bag experiment to sample the arthropod community that readily associate with detached grass litter. We tested for the effects of four grass species (two native and two exotic) and two mesh sizes on arthropod assemblages surveyed at three grassland sites in southeastern Australia. We collected 7,933 arthropods across twelve orders and found that all sites had a diverse and abundant arthropod community associated with grass litter. There was greater difference in arthropod composition among sites than among grass species or grass origin, with significant differences in the abundance of Acari, Poduromorpha and Thysanoptera. There was no effect of litter bag mesh size on the sampled arthropod community. Conservation implications : We found that both geographic and floristic factors were important drivers of variation in grassland arthropod communities linked to decomposing litter, but the drivers of these differences, and their consequences for arthropod diversity and grassland ecosystem function, remain unresolved. Further research and monitoring are needed to determine the outcome of grassland management on arthropod communities and their ecological functions.