Intergeneric salamander interactions across an ecotone

摘要

Although many field experiments have examined interactions among terrestrial salamanders or among semi-aquatic salamanders, virtually no research has examined potential interactions among salamander species across ecotones. Past research has indicated that numerous factors may influence salamander distributions, including competition, predation, and abiotic factors. We conducted a field removal experiment to investigate potential interactions among salamanders across the steam-woodland ecotone and to determine the effects of such interactions on community structure. We used removals of a terrestrial salamander, Plethodon cinereus, and/or several species of semi-aquatic salamanders of the genus Desmognathus to investigate potential interactions between these genera and the semi-aquatic salamander Eurycea cirrigera. Although removals did not significantly decrease numbers of P. cinereus or Desmognathus on plots, distribution of E. cirrigera shifted unexpectedly closer to streams in response to removals of P. cinereus. Eurycea cirrigera may have been responding to demographic shifts of P. cinereus, as average snout-vent length and mass of P. cinereus decreased significanfly on removal plots. Our results indicate that interactions among salamander species across the stream-forest ecotone influenced intergeneric responses in a complex fashion.