Long-term effects of timber harvest on ephemeral pool availability and occupancy of two obligate amphibians

Abstract/Summary

Effects of timber harvest on amphibians can be complex and persist for years post-harvest, but overall are poorly understood. We examined how timber harvest has impacted two pool-breeding species, Spotted Salamanders (Ambystoma maculatum) and Wood Frogs (Lithobates sylvaticus), across the Canaan Valley National Wildlife Refuge, WV, USA. We surveyed Spotted Salamanders and Wood Frogs at 49 pools from 2004-2016. Pools in recently harvested tracts tended to be smaller, and less likely to hold water than pools in unharvested tracts for the duration of the breeding period for the focal species. For both species, egg mass abundance was lower in harvested sites, and over time increased slightly for Spotted Salamanders but declined for Wood Frogs. Similarly, occupancy rates were lower in harvested sites for the duration of the study for both species. Occupancy rates declined over time for both species at harvested and unharvested sites; this decline was steeper for Wood Frogs in harvested sites. Our results show the importance of long-term, landscape-level studies when evaluating the effects of habitat disturbance. Understanding how forest loss and degradation impact pool-breeding amphibians will help us develop better management targets and mitigate compounding factors of decline and will be critical for the survival of these species.