The Relative Abundance of Eastern Red-Backed Salamanders in Eastern Hemlock-dominated and Mixed Deciduous Forests at Harvard Forest

Abstract

In anticipation of the loss of Tsuga canadensis (Eastern Hemlock) dominated forests due to infestation by Adelges tsugae (Hemlock Woolly Adelgid), this study assessed the relative abundance of the ecologically important terrestrial salamander, Plethodon cinereus Green (Eastern Red-backed Salamander), in five Eastern Hemlock-dominated stands and four mixed deciduous stands at Harvard Forest in Petersham, MA. Pooling data from four seasons (fall 2003-fall 2004; excluding winter), the relative abundance of P. cinereus as measured by the monitoring of artificial cover objects (ACOs) was significantly higher in Eastern Hemlock-dominated stands than in mixed deciduous stands (n = 444 P. cinereus observations). The relative abundance of P. cinereus was not significantly different in the two forest types as measured by natural cover object (NCO) searches over two seasons (fall 2003 and spring 2004), although sample sizes were small (n = 45 P. cinereus observations). This evidence that Eastern Hemlock-dominated forests provide equal or greater quality habitat for P. cinereus as mixed deciduous forests at Harvard Forest contrasts with studies from other areas of Eastern Hemlock's range, which have found the abundance of P. cinereus to be lower in this forest type. The conversion of Eastern Hemlock-dominated forest to mixed deciduous forest will have either have a negative impact or no impact on the relative abundance of P. cinereus at Harvard Forest.