Effects of timber harvesting on terrestrial survival of pond-breeding amphibians

Abstract

a b s t r a c tSuccessful forest management for multiple uses requires balancing extractive practices with maintaining biodiversity, among other important goals. Amphibians comprise an important and abundant part of the biodiversity of many forests. Previous studies have documented declines in the abundance and diversity of amphibians in harvested forests. However, only recently have studies begun to elucidate the mechanisms that underlie such declines. Here, we studied the effects of timber harvesting on survival of geographically widespread ambystomatid salamanders in three forest regions of North America. We used terrestrial enclosures in the Northeast, Midwest, and Southeast to compare amphibian survival in unharvested controls, partially harvested stands ($25% canopy reduction), and clearcuts with coarse woody debris either retained or removed. In all regions, patterns of amphibian survival were similar, with both juvenile and adult salamanders generally having significantly lower survival in clearcuts compared with unharvested controls. Survival of juvenile salamanders in partially harvested stands was also low, but adult salamanders survived as well or better in partially harvested stands as in controls. Larger body size in juveniles was significantly correlated with recapture, irrespective of treatment, in both the Northeast and Southeast, but not in the Midwest or for adults in any region. Relatively heavier adults were more likely to be captured again in the Southeast, but relative mass was not correlated with recapture in any other regions or for juveniles. Our results suggest that increased amphibian mortality may contribute to declines of amphibian abundance and richness after forest clearcutting for the regions evaluated here. Although our results indicate that partial harvesting is compatible with survival of adult salamanders, retention of intact forest around breeding ponds would benefit all terrestrial stages of pond-breeding salamanders and represents a best management practice for the maintenance of amphibian biodiversity.

Relative effects of landscape‐scale wetland amount and landscape matrix quality on wetland vertebrates: a meta‐analysis

“…Moreover, these studies show that individuals move significantly greater distances in forest compared to open areas, presumably due to higher mortality in open areas Semlitsch 2002, Popescu andHunter 2011). For example, wetland-breeding salamanders have significantly lower survival rates in clearcuts than in unharvested controls (Todd et al 2014). For example, wetland-breeding salamanders have significantly lower survival rates in clearcuts than in unharvested controls (Todd et al 2014).…”

Mining‐caused changes to habitat structure affect amphibian and reptile population ecology more than metal pollution

“…Salamanders may be particularly vulnerable to elevated temperatures, given that most salamanders tend to maintain lower body temperatures than frogs (Brattstrom 1963, Feder et al 1982) and snakes (Brattstrom 1965). Indeed, Todd et al (2009Todd et al ( , 2014 found that salamanders were more likely to avoid forest clearcuts than frogs and exhibited reduced survival in clearcuts. In addition to elevated temperatures, the absence or reduced abundance of many species were also likely caused by the lack of CWD, which is used or required for a range of important life functions, such as egg laying and shelter (LeGros et al 2014).…”

Effects of fine‐scale forest habitat quality on movement and settling decisions in juvenile pond‐breeding salamanders

“…In enclosure experiments designed to test survival, Rothermel and Semlitsch (2006) and Todd et al (2014) found that only 17% of juvenile A. maculatum survived to the end of their first growing season. Because of the acute risk of desiccation, selecting a refuge may be the single most important decision made by a juvenile amphibian in its first night of movement through terrestrial habitat (Rothermel and Luhring 2005).…”