Action: Mechanically remove mid-storey or ground vegetation
- One randomized, replicated, controlled study in the USA found that numbers of amphibian species, but not abundance, were significantly higher in plots with mechanical understory reduction compared to those without.
Removing vegetation can be used as a substitute for prescribed fire to eliminate competing mid-storey or ground vegetation. Although this technique does not have the multiple ecosystem functions provided by fire, it has advantages, such as increased selectivity and decreased risk of offsite fire damage.
Other studies that control mid-storey or ground vegetation are discussed in ‘Use herbicides to control mid-storey or ground vegetation’.
Supporting evidence from individual studies
A randomized, replicated, controlled study in 2001–2004 of upland hardwood forest in North Carolina, USA (Greenberg & Waldrop 2008) found that mechanical understory reduction significantly increased amphibian species richness, but not abundance. Species richness was significantly higher in understory reduction plots compared to controls (6 vs 3). However, there was no significant difference in the relative abundance of total amphibians compared to controls (18 vs 17 captured/100 nights), total anurans (frogs and toads; 11 vs 10), salamanders (8 vs 4), American toads Bufo americanus (10 vs 10) or green frog Rana clamitans (2 vs 1). There were three randomly assigned replicates of treatment and control plots. Mechanical removal of shrubs was undertaken in winter 2001–2002 using chainsaws. Drift-fences with pitfall and funnel traps were used for monitoring in August–October 2001 and May–September 2002–2004.