Action: Retain riparian buffers in logged areas
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- Two studies evaluated the effects of retaining riparian buffers in logged areas on bat populations. The two studies were in Australia.
COMMUNITY RESPONSE (1 STUDY)
- Richness/diversity (1 study): One replicated, site comparison study in Australia found a similar number of bat species in riparian buffers within logged forest, regrowth forest and mature forest.
POPULATION RESPONSE (1 STUDY)
- Abundance (1 study): One replicated, site comparison study in Australia found similar total bat activity (relative abundance) in riparian buffers within logged forest, regrowth forest and mature forest.
USAGE (1 STUDY)
- Use (1 study): One replicated, site comparison study in Australia found that southern forest bats roosted less often in riparian buffers in logged forest than in unlogged forest, but Gould’s long-eared bats had a similar number of roosts in riparian buffers in logged forest, remnant trees in logged areas and unlogged forest.
This intervention involves retaining unlogged buffers along streams and rivers (riparian buffers or corridors). This may provide foraging and roosting opportunities for bats and maintain connectivity in disturbed landscapes. See also ‘Retain forested corridors in logged areas’.
For an intervention that involves planting riparian buffers to reduce pollution, see ‘Threat: Pollution – Agricultural and forestry effluents – Plant riparian buffer strips’.
Supporting evidence from individual studies
A replicated, site comparison study in 2003 of 60 forest sites in New South Wales, Australia (Lloyd et al 2006) found that riparian buffers in logged forest had similar overall bat activity and number of bat species as riparian buffers in regrowth forest and mature forest, but one bat species was three times more active in riparian corridors than in mature forest. There was no significant difference in total bat activity or the number of bat species recorded in riparian buffers in logged forest (average 1.9 bat passes/hour, 0.3 species/hour), riparian buffers in regrowth forest (1.5 bat passes/hour, 0.3 species/hour) or mature forest (1.4 bat passes/hour and 0.4 species/hour). One bat species, the eastern forest bat Vespadelus pumilus, was three times more active in riparian buffers in logged forest than in mature forest (data not reported). Five replicates of four sizes of stream () were sampled for three treatments: riparian buffers (10–50 m minimum width) in logged areas (thinned and/or selectively logged in the last six years), riparian buffers in regrowth forest (logged 15–30 years ago), and mature forest (undisturbed for >50 years). At each of 60 sites, bat activity was recorded for two consecutive nights in January–April 2003.
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 riparian buffers in logged areas had more roosts of southern forest bats Vespadelus regulus than shelterwood or gap release logged forest, but Gould’s long-eared bats Nyctophilus gouldi had a similar number of roosts in riparian buffers and shelterwood logged forest and fewer roosts in gap release logged forest. More southern forest bat roosts were in riparian buffers (five roosts, 24%) than in shelterwood or gap release logged forest (one roost, 5% in shelterwood; no roosts in gap release). A similar number of Gould’s long-eared bat roosts were in riparian buffers (eight roosts, 30%) and shelterwood logged forest (10 roosts, 37%), but fewer roosts were in gap release logged forest (one roost, 4%). Riparian buffers had been undisturbed for >30 years. Shelterwood forest had retention levels of 40–60%. Gap release forest had 95% of the mature overstory removed. 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.
- Lloyd A., Law B. & Goldingay R. (2006) Bat activity on riparian zones and upper slopes in Australian timber production forests and the effectiveness of riparian buffers. Biological Conservation, 129, 207-220
- Webala P.W., Craig M.D., Law B.S., Wayne A.F. & Bradley J.S. (2010) Roost site selection by southern forest bat Vespadelus regulus and Gould's long-eared bat Nyctophilus gouldi in logged jarrah forests; south-western Australia. Forest Ecology and Management, 260, 1780-1790