Riparian disturbance restricts connectivity of Appalachian stream salamander populations at the Coweeta Hydrologic Laboratory

Human populations are rapidly expanding and encroaching on previously undisturbed habitats. Stream salamanders in the southern Appalachian Mountains are a diverse and abundant group threatened by rapid exurban development in high-elevation watersheds. Previous research has demonstrated the sensitivity of salamanders to urbanization, but little research exists describing the mechanisms behind population declines and extirpations. Appalachian stream salamanders are adapted to forested streams with dense overstory and little light, yet following urbanization, light gaps associated with land clearing emerge. Light avoidance behaviors may alter movement behaviors of salamanders, fragmenting populations on opposite sides of light gaps. To study the effects on riparian disturbance on salamanders we established 6 experimental sites with canopy gaps ranging from 13m to 85m in stream length and 2 control sites lacking canopy gaps in May of 2010. Animals were collected within these plots, marked, and translocated to the plot on the opposite side of the gap. To establish detection probabilities in the absence of translocation, we established an additional 10m plot in the forest at each site where individuals were captured, marked, and re-released within this area. Recaptured individuals were measured and in some cases re-marked if those individuals had returned to their capture location.