Edge Effects of Gated and Ungated Roads on Terrestrial Salamanders

Abstract

ABSTRACTRoads through forest habitats reduce the abundance of many animal species. These reductions are often referred to as edge effects and their causes include roadkill, degradation of forest habitat, and changes in biotic interactions. Which of these causes are operating can have important implications for management. Terrestrial salamanders in the southern Appalachians have previously been shown to be subject to edge effects from forest roads that are open to traffic. In this study, I examined edge effects on red‐backed salamanders (Plethodon cinereus) along forest roads that were either open or gated to prevent vehicle entry. I also included roads that varied in the width of the gravel surface, the width of the roadside verge, and the magnitude of habitat gradients at the forest edge. I found that ungated roads were associated with consistent edge effects on salamanders, whereas no detectable edge effects were found for gated roads. Road width was as good a predictor of the magnitude of edge effects as was the presence of a gate, though the width of the roadside verge was largely unrelated to the magnitude of edge effects. Gradients in habitat variables (soil moisture, temp, leaf litter thickness) were not closely related to the magnitude of edge effects. These results demonstrate that narrow, gated roads do not typically produce edge effects on terrestrial salamanders of the same magnitude as wider, ungated roads. In addition, the apparent importance of road type or road width and the relative unimportance of habitat characteristics suggest that traffic‐related factors may be a substantial contributor to edge effects on terrestrial salamanders. These findings provide some support for the closing of redundant forest roads as a low‐cost method for diminishing the negative effects of roads on forest ecosystems.