Residual Effects of Thinning and High White-Tailed Deer Densities on Northern Redback Salamanders in Southern New England Oak Forests

Abstract

Research has demonstrated that even-aged regeneration harvests, especially clearcutting, can have a major and long-lasting detrimental effect on forest amphibians, but the effects of less intensive silvicultural treatments have not been well documented. Additionally, the chronic overabundance of white-tailed deer (Odocoileus virginianus) has become a problem in many parts of North America, with associated effects on vegetation composition and structure and on other wildlife. I assessed the effects of crown thinning and deer overabundance on the relative abundance of forest-floor salamanders in a southern New England mixed oakhardwood forest. I surveyed salamanders by using cover boards in 16 forest stands with thinned or unthinned treatments and with histories of low (3-6 deer/km2) or high (10-17 deer/km2) deer densities. Surveys were conducted 5 times a year for 3 years. Northern redback salamanders (Plethodon cinereus) were the dominate species in all surveys and in all treatment classes. Redbacks were most abundant in spring and fall surveys and in the second and third year of the study. Neither thinning nor white-tailed deer density had a significant effect on the number of redback observations: stands with high numbers of redbacks occurred in all treatment classes.