Copies of the following paper available from David Lindenmayer
I have appended the abstract
Ecological Monographs: Vol. 72, No. 1, pp. 1?18.
EFFECTS OF FOREST FRAGMENTATION ON BIRD ASSEMBLAGES IN A NOVEL LANDSCAPE CONTEXT
David B. Lindenmayer4 and Henry Nix
Centre for Resource and Environmental Studies, Australian National University,
Canberra, A.C.T., 0200, Australia
Ross B. Cunningham and Christine F. Donnelly
Statistical Consulting Unit, Australian National University, Canberra, A.C.T.,
0200, Australia
Bruce D. Lindenmayer
17 Monkman Street, Chapman, A.C.T., 2611, Australia
We report findings of a large-scale study in a 100000-ha subsection of the Tumut
region in southern New South Wales, southeastern Australia. The study was
designed to measure the effects of landscape context and habitat fragmentation
on forest birds. The study region consisted of a forest mosaic characterized by
different landscape contexts: large, continuous areas of native Eucalyptus
forest, extensive stands of exotic softwood (radiata pine, Pinus radiata)
plantation, and remnant patches of native Eucalyptus forest scattered throughout
the extensive areas of radiata pine plantation. A set of 85 eucalypt remnants
was randomly selected across several stratifying variables: four patch size
classes (1?3 ha, 4?10 ha, 11?20 ha, and >20 ha), two isolation age classes (<20
years and >20 years since fragmentation), and five dominant eucalypt forest type
classes. In addition to the 85 eucalypt remnants, a further 80 3-ha sites were
selected for study: 40 in large, continuous areas of eucalypt forest and 40 in
radiata pine stands. Point-interval counts of forest birds at the 165 sites were
conducted in 1996 and 1997.
Of 90 species recorded, 23.1 species (95% confidence interval, 22.0, 24.2
species), on average, were present in continuous eucalypt forest, 20.6 (19.5,
21.7) species in patch-shaped eucalypt remnants, 20.6 (19.5, 21.7) species in
strip-shaped eucalypt remnants, and 16.7 (15.6, 17.8) species in radiata pine.
Strong gradients in bird assemblages were found. These gradients were governed
by a combination of landscape context, remnant size, and remnant shape effects,
and, in the case of radiata pine sites, the extent of native forest surrounding
the pine. These gradients could, in part, be explained by bird life history
attributes such as foraging guild and nesting
height. For example, birds more often detected in patch-shaped remnants were
smaller, produced smaller clutches, were more likely to be migratory, and
typically had cup nests or burrows.
The results of our study showed that eucalypt fragments of all sizes and shapes
have significant conservation value. This is because they contain many native
species of birds, some of which are more abundant in fragments than they are in
continuous eucalypt forests, and also because they increase native bird
populations in nearby non-native pine plantations.
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
