Effects of red-backed salamanders on ecosystem functions

• Published in: PloS one Vol. 9; no. 1; p. e86854
• Main Authors: Hocking, Daniel J, Babbitt, Kimberly J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.01.2014; Public Library of Science (PLoS)
• Subjects: Amphibia; Amphibians; Analysis; Analysis of Variance; Animals; Beetles; Biology; Cascades; Caudata; Ecology; Ecosystem assessment; Ecosystems; Environmental conditions; Food Chain; Food chains; Forest ecology; Forest ecosystems; Forests; Germination; Germination - physiology; Herbivores; Insects; Mineralization; New Hampshire; Nitrification; Nitrogen - metabolism; Nutrient dynamics; Plant Leaves - metabolism; Plethodon cinereus; Population Density; Predators; Quercus - growth & development; Reptiles & amphibians; Seedlings; Spiders; Terrestrial ecosystems; Terrestrial environments; Urodela - physiology; Wood; Wood - metabolism; New Hampshire; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0086854

Ecosystems provide a vast array of services for human societies, but understanding how various organisms contribute to the functions that maintain these services remains an important ecological challenge. Predators can affect ecosystem functions through a combination of top-down trophic cascades and bottom-up effects on nutrient dynamics. As the most abundant vertebrate predator in many eastern US forests, woodland salamanders (Plethodon spp.) likely affect ecosystems functions. We examined the effects of red-backed salamanders (Plethodon cinereus) on a variety of forest ecosystem functions using a combined approach of large-scale salamander removals (314-m(2) plots) and small-scale enclosures (2 m(2)) where we explicitly manipulated salamander density (0, 0.5, 1, 2, 4 m(-2)). In these experiments, we measured the rates of litter and wood decomposition, potential nitrogen mineralization and nitrification rates, acorn germination, and foliar insect damage on red oak seedlings. Across both experimental venues, we found no significant effect of red-backed salamanders on any of the ecosystem functions. We also found no effect of salamanders on intraguild predator abundance (carabid beetles, centipedes, spiders). Our study adds to the already conflicting evidence on effects of red-backed salamander and other amphibians on terrestrial ecosystem functions. It appears likely that the impact of terrestrial amphibians on ecosystem functions is context dependent. Future research would benefit from explicitly examining terrestrial amphibian effects on ecosystem functions under a variety of environmental conditions and in different forest types.