Use shelterwood harvesting
Overall effectiveness category Awaiting assessment
Number of studies: 2
Background information and definitions
Shelterwood harvesting is a management technique designed to obtain even-aged forests. It involves harvesting trees in a series of partial cuts, with trees removed uniformly over the plot. This allows new seedlings to grow from the seeds of older trees. This can help to maintain distinctive forest species and increase forest structural diversity.
Supporting evidence from individual studies
A replicated, randomized study in 2001–2005 in three sites of secondary broadleaf forest in Alabama, USA (Felix et al. 2008) found that using shelterwood harvesting resulted in lower abundance of juvenile eastern box turtles Terrapene carolina Carolina compared to areas that were clearcut. Abundance was lower in shelterwood plots (0.001 turtles/trap night) compared to clearcut plots (0.002 turtles/trap night). In autumn 2001, three sites were split in to three plots (4 ha plots), and plots were randomly selected for shelterwood harvesting (25–50% tree retention; 2 plots/site) or clearcutting (0 % retention, 1 plot/site). Trees were felled with a chainsaw and dragged out (using a grapple skidder). In July–August 2002 and March–September 2003–2005, three drift fences (15 m long) and three artificial pools for capturing reptiles (91 x 61 x 46 cm, buried in centre of each plot) were installed in each plot. Drift fences were opened intermittently for periods of five days and checked daily for a total of 1,455–1,575 trap nights/patch.Study and other actions tested
A replicated, randomized, controlled, before-and-after study in 2008–2014 in an upland mixed oak forest in the Appalachians, USA (Greenberg et al. 2016) found that shelterwood harvesting increased lizard but not overall reptile and snake species richness and abundance compared to no management. Overall lizard species richness and capture rates increased after shelterwood harvesting (species richness: 0.8–1.5 species/100 fence nights, abundance: 0.5–1.3 individuals/100 fence nights) compared to no management (0, 0–0.1). Overall reptile and snake species richness and abundance were similar after shelterwood harvesting (overall reptile abundance: 0.7–1.7 captures/100 fence nights), compared to no management (overall reptile abundance: 0.2–0.7 captures/100 fence nights; snake abundance and all reptile and snake species richness data presented as model outputs). See paper for changes in individual species abundances. Shelterwood harvesting was carried out in 2009–2010 in 4–5 replicate plots of 225 x 225 m. Trees were felled with chainsaws and grapple cutters and dragged to log landings. Monitoring took place using drift fences, pitfall and funnel traps in May-August one year pre-treatment (2008) and five years post treatment (sampled in 2010, 2011, 2013, 2014). Plots of the same size and number without any management applied were monitored at the same time.Study and other actions tested