Action: Use shelterwood cutting instead of clearcutting
- One study evaluated the effects of using shelterwood cutting instead of ‘gap release’ cutting on bat populations. The study was in Australia. We found no studies that evaluated the effects of shelterwood cutting instead of clearcutting.
COMMUNITY RESPONSE (0 STUDIES)
POPULATION RESPONSE (0 STUDIES)
USAGE (1 STUDY)
- Use (1 study): One site comparison study in Australia found more Gould’s long-eared bats roosting in remnant trees within forests that had been shelterwood harvested than in forests harvested using gap release methods. Comparisons were not made with clearcutting.
There are several different shelterwood systems. The basic process is the selective removal of overstorey trees to allow enough light through to the forest floor to create new, even aged stands below. The remaining mature overstorey trees provide seeds for regeneration and create shelter for the younger trees. Harvesting is done in a series of cuts and may also involve thinning of the lower forest canopies.
Supporting evidence from individual studies
A replicated, site comparison study in 2009 of 21 radiotracked bats in jarrah Eucalyptus marginata forest in south-western Australia (Webala et al 2010) found that shelterwood harvested forests had more Gould’s long-eared bat Nyctophilus gouldi and southern forest bat Vespadelus regulus roosts than gap release forests. More Gould’s long-eared bat roosts were in remnant trees in shelterwood forests (10 roosts, 37%) than in gap release forests (one roost, 3%). The remainder of tracked Gould’s long-eared bats roosted in mature forest (eight roosts, 30%) and riparian buffers (eight roosts, 30%). Only one southern forest bat roost was found in shelterwoods, and none in gap release forests. Most southern forest bat roosts were in mature unlogged forest (15 roosts, 71%) and riparian buffers (five roosts, 24%). Shelterwood forest had retention levels of 40–60%. Gap release forest had 95% of the mature overstory removed. Riparian buffers and mature forest areas had been undisturbed for >30 years. Eleven Gould’s long-eared bats and 10 southern forest bats were caught with harp traps at two water holes and radiotracked for 3–8 days in February–March 2009.