Individual study: Effects of riparian timber management on amphibians in Maine
Perkins D.W., Malcolm L. & Hunter J.R. (2006) Effects of riparian timber management on amphibians in Maine. Journal of Wildlife Management, 70, 657-670
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Thin trees within forests
A replicated, site comparison study in 2000–2003 of 12 harvested hardwood forest sites in Maine, USA (Perkins, Malcolm & Hunter 2006) found that abundance of amphibian species in partially harvested forest was similar or lower than unharvested forest and similar or higher than clearcut forest. Captures in partial harvests were significantly lower than unharvested forest and higher than clearcuts for red-backed salamanders Plethodon cinereus (partial: 0.38; clearcut: 0.12; unharvested: 0.61/100 trap nights) and spotted salamanders Ambystoma maculatum (partial: 0.03; clearcut: 0.01; unharvested: 0.09). There was no significant difference between treatments for two-lined salamanders Eurycea bislineata (partial: 0.12; clearcut: 0.04; unharvested: 0.16), American toads Bufo americanus (partial: 1.01; clearcut: 0.49; unharvested: 0.34) or wood frogs Rana sylvatica (partial: 0.99; clearcut: 0.92; unharvested: 1.54). Twelve headwater streams that had been harvested 4–10 years previously were selected. Treatments were: partial harvest (23–53% removed), clearcut with 23–35 m buffers and unharvested for > 50 years. Monitoring was undertaken in June–September in one year using drift-fences with pitfall traps and visual surveys.
Retain riparian buffer strips during timber harvest
A randomized, replicated, controlled, before-and-after study in 2000–2003 of forest in Maine, USA (Perkins, Malcolm & Hunter 2006) found that amphibian abundance tended to be higher when riparian buffers were retained during harvest. Captures were significantly higher with 11 m and 23 m buffers for American toads Bufo americanus (clearcut: 0.6; 11 m buffer: 1.0; 23 m buffer: 3.4; unharvested: 0.5/100 trap nights) and wood frogs Rana sylvatica (clearcut: 0.8; 11 m: 1.4; 23 m: 2.0; unharvested: 2.2). Red-backed salamanders Plethodon cinereus did not differ (0.1–0.3). In forest cut 4–10 years previously, captures of wood frog and American toads were also significantly higher in buffers than clearcuts. Red-backed salamanders showed a similar trend. However, abundance of salamanders and frogs were significantly or tended to be lower in buffers than unharvested forest. Fifteen headwater streams were randomly assigned to 6 ha treatments: clearcut with buffers of 0, 11 or 23 m wide, partial harvest (23–53%) or unharvested. Monitoring was undertaken using drift fences with pitfall traps and visual surveys in June–September, one year before and two years after harvesting. Twelve sites harvested 4–10 years earlier were also monitored in one year. Treatments were: clearcutting with 23–35 m buffers, partial harvest and unharvested (> 50 years).