Thesis
Aspects of the ecology of the koala, Phascolarctos cinereus, in a tall coastal production forest in north eastern New South Wales
Southern Cross University
Doctor of Philosophy (PhD), Southern Cross University
2012
DOI:
https://doi.org/10.25918/thesis.150
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Abstract
The aim of this study was to document the effects of residual forest stand condition on its suitability as habitat for koalas, to test if habitat structure and floristics are pivotal to explaining koala distribution and abundance, and to test a proposed management strategy for koala conservation in a forest environment that has been managed for timber production for over 100 years. Vegetation structure and floristics were characterised by vegetation plot assessments. Forty two koalas were caught to undertake health assessments and radio-tracked to determine diurnal shelter trees, koala home-range size and selection of vegetation zones as habitat. Faecal pellet analysis determined koala food preferences. This was a structurally and floristically diverse forest with a widespread distribution of koala food trees. A new zonation system, derived from vegetation plot assessment, included four zones based on the variables of total species richness and ‘koala feed tree’ species richness. The estimated koala population density was 0.02 koalas per ha and the median home range size for the population was 9.3 ha (adaptive kernel (ADK) 95%). The vegetation within koala home ranges was characterised by higher proportions of eucalypts and koala feed tree species than available randomly through the forest. They also contained a higher proportion of smaller trees (20-30 cm DBH) and large trees (50+ cm DBH). The koalas showed a preference for trees greater than 20 cm DBH but the largest size class (50+ cm DBH) was not always the most preferred. Faecal cuticle analysis confirmed that Eucalyptus microcorys, E. saligna, E. propinqua and Allocasuarina torulosa were the primary koala feed tree species (KFTS) in this forest. Chlamydial disease was prevalent and the incidence of sub-clinical Chlamydia was approximately twice that for koalas observed with clinical symptoms, typically conjunctivitis (70.8%-17.6% c.f. 33.3%-11.8% respectively). A low intensity, single tree selection, experimental logging operation was conducted that resulted in the reduction of basal areas of eucalypts (the target species) but the KFTS were relatively unaffected, as specified by the harvesting protocols. The species composition and richness did, to a large extent, define the quality of the habitat for koalas, particularly with respect to the species richness of the primary browse species. The more floristically diverse a forest is, the greater its structural diversity so these two variables can be difficult to tease apart. The impacts of timber production and harvesting activities that target primary browse species need further research.
Details
- Title
- Aspects of the ecology of the koala, Phascolarctos cinereus, in a tall coastal production forest in north eastern New South Wales
- Creators
- Sally Louise Radford Miller
- Contributors
- Ross Goldingay (Supervisor) - Southern Cross UniversityRod Kavanagh (Supervisor) - Southern Cross UniversityJeff J McKee (Supervisor) - Southern Cross University
- Awarding Institution
- Southern Cross University; Doctor of Philosophy (PhD)
- Theses
- Doctor of Philosophy (PhD), Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- [xxvi] 330
- Identifiers
- 991012947800502368
- Copyright
- © SL Radford Miller 2012
- Academic Unit
- School of Environment, Science and Engineering; Faculty of Science and Engineering
- Resource Type
- Thesis