This study is concerned with programs to conserve remnant stands
of native vegetation in the agricultural regions of South Australia
and concentrates on the development of explicit evaluation procedures
which reflect stated conservation objectives. As botanical data are
available for stands of native vegetation in most of the agricultural
regions, stands in a particular region are able to be compared rather
than assessed in isolation. Based on a review of conservation
evaluation schemes in Australia and overseas, a hierarchical evaluation
procedure using multiple criteria to compare stands was applied
to stands of vegetation in the Mount Lofty Ranges.
The conservation objective, of preserving samples of all plant
communities in a region, led to the analysis of existing botanical data
from two surveys of the Mount Lofty Ranges, to provide the basis for
an inventory of regional plant communities. These surveys included 52
remnant stands of native vegetation and employed a point-centred quarter
plotless sampling technique to summarise the vegetation. Numerical
classificatory analysis of the raw sampling point data produced a more
comprehensive floristic summary than the results from the plotless
sampling. These floristic groups were correlated with physical
environmental variables to produce an inventory of 45 regional vegetation
types, as the first stage in the conservation evaluation of stands.
Evaluation criteria of size, species richness and species rarity
were quantified and used to select examples of each vegetation type on
the basis of overall satisfaction of the criteria. In addition, the
smallest suite of stands, in which all the vegetation types were represented,
was determined, and was shown to be 24 stands. All of these
were included in the 37 stands chosen using the three criteria. A third
evaluation stage used stand parameters such as plant community richness
to give a priority ranking of the 37 stands.
A polythetic divisive classification of the vegetation types was
developed to provide a means of evaluating communities in stands of
native vegetation yet to be sampled in the region, and of comparing
the vegetation types with communities in existing reservesr Examination
of species-sampling area relationships led to recommended plot
sizes for such future vegetation surveys in the Mount Lofty Ranges.
The ease of collecting floristic data and the extensive time involved
in quantitative measurements suggest that all perennial plant species
be recorded and only estimations be made of vegetation quantity and
structure for each sampling plot.
This study demonstrates the usefulness of numerical classification
techniques for conservation evaluation, and of continuous variables to
quantify criteria of conservation value; and the application of those
criteria in an explicit, hierarchical conservation evaluation procedure.
| Identifer | oai:union.ndltd.org:ADTP/219216 |
| Date | January 1983 |
| Creators | Mitchell, Leslie Howard, n/a |
| Publisher | University of Canberra. Applied Science |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | ), Copyright Leslie Howard Mitchell |
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