New paper out in Journal of Animal Ecology! This paper surveyed 54 North American grasslands to investigate whether bottom-up or top-down control regulates ecological communities. We examined the biomass of four common grassland arthropod taxa— Auchenorrhyncha, sucking herbivores, Acrididae, chewing herbivores, Tettigoniidae, omnivores, and Araneae, predators.
We found that sucking herbivores and omnivores tracked plant biomass and chewing herbivores tracked plant quality. In addition, we found that when spider biomass was low, herbivores increased with plant biomass but this didn’t happen at high spider abundances. Furthermore, stable isotope analysis showed that neither predator biomass nor trophic position changed with plant biomass, suggesting predators themselves are top-down limited. Finally, the trophic position of chewing herbivores and omnivores increased with plant biomass, suggesting increased scavenging in grasslands with increased carbohydrate availability.
This was a fun paper to work on. You can click here to read the whole paper.
Rebecca M. Prather 