Effects of Timbering on Plethodon Hubrichti Over Twelve Years

Abstract

Clearcuts have been shown to adversely affect salamander populations, whereas impacts from milder forms of timbering are more variable. We determined the effects of clearcuts and shelterwood cuts on populations of the Peaks of Otter Salamander (Plethodon hubrichti) using counts of surface active salamanders found during multiple night collections. Sampling was done prior to and then periodically after timbering for 12 yr. Overall, the long-term trends in mean number of P. hubrichti at reference and shelterwood cut sites were not significantly different. In contrast, means at clearcut sites declined 41% during the first year posttimbering and then declined over the next three years to a low of 75% below pretimbering means. The means stabilized at 45% below pre-timbering means for the remainder of the study. Immediately after timbering 41% of the salamanders moved from transects established at the edge of clearcuts to reference transects that were 3-9 m away. Clearcuts had less canopy closure and dead leaf cover than reference and shelterwood cuts which likely degraded habitat for salamanders. Therefore, clearcutting forests is not advisable because of adverse impacts on salamanders, but forms of timbering that retain a portion of the forest canopy may be acceptable if it can be shown that the timbering method does not reduce salamander populations. Clearcut harvesting of timber adversely af- fects salamander populations. Various study designs have been used to assess impacts, with the most common one being a comparison of counts of salamanders found in plots or transects in mature forests with similar plots or transects found in nearby tracts of forests that were clearcut various years prior to the study being conducted (reviewed extensively in de- Maynadier and Hunter, 1995; Dupuis and Bunnell, 1999; Grialou et al., 2000; DeGraaf