Experimental assessment of salamanders as predators of detrital food webs: effects on invertebrates, decomposition and the carbon cycle

Declines in amphibian populations and the loss of some species has spurred research into the causes of declines. Little research has been done on what the loss of amphibian species may mean to ecosystem function. I describe a field experiment where the number of Plethodon cinereus (the red-backed salamander) was manipulated in enclosures buried in the forest floor. I determined the composition of the forest floor invertebrate community and the rare of decomposition of leaf litter in enclosures with and without salamanders over 4.5 months. Salamander predation in enclosures significantly reduced invertebrate numbers compared to control enclosures. Salamander predation also indirectly reduced rate of decomposition by between 11 and 17%. This was probably due to salamanders consuming a significant number of leaf fragmenters (e.g. Coleoptera and Diptera larvae). Predation on leaf litter fragmenters may alter carbon dynamics in forested ecosystems.