The influence of red-backed salamanders (Plethodon cinereus) on nutrient cycling in Appalachian hardwood forestsThis article is part of a larger document. View the larger document here.
The use of amphibians as biological indicators of ecosystem health has received considerable attention because of the increasing importance placed upon maintaining biodiversity in forested ecosystems. In this study, we imposed three different eastern red-backed salamander (Plethodon cinereus) treatments: 1) low (n = 4; added 0 salamanders to each mesocosm), 2) medium (n = 4; added 3 salamanders each mesocosm) and 3) high (n = 4; added 6 salamanders to each mesocosm), into 3-m2 in situ field enclosures to monitor the potential effects of salamander abundance on the availability of nitrogen (N). Cationic and anionic exchange membranes were placed horizontally under the forest floor and vertically within the A-horizon to index N-availability through time. There was significantly more nitrate (p < 0.001) under the forest floor in the low and medium salamander density treatments than the high density treatments. No consistent treatment by time interaction trends were observed for any measures of inorganic N. At this juncture of the experiment, we would reject the research hypothesis that nutrient availability increases as salamander abundance increases.