Abundance, biomass production, nutrient content, and the possible role of terrestrial salamanders in Missouri Ozark forest ecosystems

The transfer of energy and nutrients largely depends on the role of animals in the movement of biomass between trophic levels and ecosystems. Despite the historical recognition that amphibians could play an important role in the movement of biomass and nutrients, very few studies have provided reliable estimates of abundance and density of amphibians to reveal their true importance. Here, we provide robust estimates of abundance and density of a dominant species, the Southern Redback Salamander (Plethodon serratus Grobman, 1944), in the oak forest ecosystem of the Ozark Highlands in Missouri. We then use the abundance and density estimates to calculate biomass and nutrient content of salamanders at our study sites in the Ozark forests. Salamanders at the Sinkin Experimental Forest comprise a large amount of protein, energy, and nutrients that greatly exceed estimates derived some 35 years ago in the Hubbard Brook Experimental Forest, New Hampshire. Our estimates (7 300-12 900 salamanders.ha(-1)) are 2-4 times greater than the values reported by Burton and Likens (1975a, Ecology, 56: 1068-1080; 1975b, Copeia, 1975: 541-546). Furthermore, we show that density estimates of other small plethodontid species reported in the literature are nearly an order of magnitude greater than that reported by Burton and Likens. We believe this indicates that previous results have underestimated the importance of salamander biomass, nutrient, and energy flux, and their functional role in regulating invertebrates and carbon retention in forest ecosystems.