ARS | Publication request: Habitat relationships of eastern red-backed salamanders (Plethodon cinereus) in Appalachian grazing systems

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 9, 2007
Publication Date: N/A

Interpretive Summary: Woodland salamanders (Plethodon spp.) are important contributors to biodiversity and trophic processes within Appalachian forests. Several studies indicate that altered microclimates and vegetation structure after timber harvest (e.g., increased soil temperatures and desiccation, reduced ground cover) may result in long-term population declines of some Appalachian salamanders. Conversion of forests to pastures or meadows is believed to result in more severe and permanent impacts on salamander habitat quality. However, virtually no data exist regarding woodland salamander responses to Appalachian grazing systems. The red-backed salamander (Plethodon cinerus) is one of the most abundant salamanders in many forests of eastern North America and has been widely used as an indicator of forest disturbance; for this reason, it was selected as our species of focus for assessing woodland salamander response to agricultural disturbance. We used an information-theoretic approach to evaluate responses of red-backed salamanders to silvopasture (integrated livestock grazing and forest management) and meadow conversion treatments in Southern West Virginia. Salamander presence and abundance were positively associated with increasing cover of herbaceous vegetation and negatively associated with the intensity of disturbance. Although populations of salamanders appeared to respond negatively to agricultural treatments in comparison to forest reference plots, the occurrence of red-backed salamanders within agriculturally-modified habitats indicates that this species may be more resilient to forest conversion than previously thought. We suggest that the loss of forest canopy for red-backed salamanders may be at least partially mitigated by retaining dense herbaceous vegetation and artificial cover within agricultural treatments.

Technical Abstract: Altered microclimates and vegetation structure after timber harvest can result in longterm population declines of some Appalachian salamanders. If changes in forest structure following harvest alter woodland salamander habitat quality, conversion of forests to pastures or meadows is believed to result in more severe and lasting impacts. However, woodland salamander responses to established or newly-created Appalachian grazing systems are virtually unknown. We used an information-theoretic approach to evaluate responses of red-backed salamanders (Plethodon cinereus) to silvopasture and meadow conversion treatments in southern West Virginia. Searches of artificial coverboards in northern red oak (Quercus rubra) silvopasture (6.7 m2/ ha basal area), hay meadow (>5 years after forest conversion), forest edge, and reference forest plots yielded 2,749 salamanders between May 2004 and November 2005. Akaike¿s Information Criterion (AIC) model selection indicated that models containing the variables percent herbaceous vegetation and treatment type best explained salamander presence and abundance in both years. Salamander presence and abundance were positively associated with increasing cover of herbaceous vegetation and negatively associated with the intensity of disturbance. Although presence and abundance appeared to respond negatively to agricultural treatments in comparison to reference forest plots, the occurrence of red-backed salamanders within agriculturally-modified habitats indicates this species may be more resilient to forest conversion than previously thought. We suggest that dense herbaceous vegetation retained within some agricultural treatments, in combination with artificial cover, may at least partially mitigate the loss of forest canopy for red-backed salamanders.