Fear of Predation Slows Plant-Litter Decomposition

Fear Itself A direct connection exists between aboveground communities and belowground soil microbiota: Soil microbes break down detrital inputs from above. Generally, it has been assumed that this relationship is largely driven by the soil community and the quality of the unconsumed plant-matter that makes up the majority of detritus in most ecosystems. However, Hawlena et al. (p. 1434 ) found that grasshoppers exposed to the threat of spider predation have an altered carbon to nitrogen ratio. When these grasshopper carcasses were subsequently integrated into the plant litter, they significantly slowed the decomposition rate, although there was no impact on the rate of decomposition of the grasshoppers themselves. Thus, the mere presence of predators, and the stress they impose, can have cascading trophic impacts and even influence the process of decomposition.