The value of unlogged buffers for vulnerable bird species in the jarrah forest of south-west Western Australia

Abstract

Retaining strips of unlogged forest, called buffers, is a common strategy for maintaining populations of vulnerable species in production forests in Australia. I conducted a study to examine the effectiveness of buffers in maintaining populations of vulnerable bird species in jarrah forests of southwest Western Australia. I examined changes in the population densities of all bird species in buffers in the first 12 months after logging and compared these to changes in logged and unlogged forest. I also conducted detailed ecological studies on Golden Whistlers to determine whether buffers were important for this species and, if so, why they were important. Buffers were important in maintaining populations of vulnerable bird species after the first logging rotation. Of the six species that declined after logging, only one (the Golden Whistler) showed a significant decrease in buffers and the decrease was less than in logged forest. Buffers were important for Golden Whistlers in providing both foraging and nesting sites. Whistlers also moved the location of their territories to include buffers, indicating that they are critical for this species in production forests. Given their importance to vulnerable species, I recommend that buffers are not logged at the second logging rotation until research is conducted that demonstrates that the surrounding logged forest has matured sufficiently to support viable populations of vulnerable species.

The short‐term effects of edges created by forestry operations on the bird community of the jarrah forest, south‐western Australia

“…Both gap and shelterwood are selective logging methods, with gaps removing 85-95% and shelterwoods removing 40-60% of basal area (Stoneman et al 1989) (see Craig 2004 for photographs of gaps, shelterwoods and shelterwood/unlogged edges). Gaps can be a maximum of 10 ha and unlogged buffers, at least 100 m wide, must be retained between gaps.…”

“…Gaps can be a maximum of 10 ha and unlogged buffers, at least 100 m wide, must be retained between gaps. In addition to buffers, the forest is not logged if it is of low commercial value (see Craig 2004), so large areas of unlogged forest may remain in some logging coupes. No unlogged buffers are retained between gaps and shelterwoods or within shelterwoods; there is no maximum size for shelterwoods.…”

“…Deviations from this shape are common, due to factors such as the location of ridge lines, creekline buffers or forest of low commercial quality, so the length of gap edge created during logging operations is variable. Shelterwood areas can be of any shape and produce variable lengths of shelterwood edge (see Craig 2004).…”