NSW Bitou Bush Threat Abatement Plan - Department of ...

Threat Abatement Plan - Invasion of native plant communities by Chrysanthemoides monilifera
< on the Rare Or Threatened Australian Plants (ROTAP: Briggs and Leigh 1996) list
< on the Australian Threatened Flora list (ANZECC 1999)
< listed by Sheringham and Westaway (1995)
< referred to as threatened in other publications
While this approach provided a basis for establishing those threatened plant species which may be
at risk from bitou bush invasions, and thus be subjected to analysis of the threat, it does not
address plant species not formally listed as threatened but which are likely to be or are at risk from
invasion. Therefore consideration of both threatened species and non-threatened species that are
potentially at risk by bitou bush is needed to establish a complete list of the species at risk. Such
an approach is supportive of the KTP determination in which it was acknowledged that bitou bush
invasion may cause species that are not threatened to become so (NSW SC 1999a).
In order to determine the full extent of the species at risk, the Weed Impacts to Native Species
(WINS) assessment process or tool was established (see Downey in press). The WINS assessment
process involves four stages, being 1) a review of the literature; 2) collation and assessment of the
knowledge from land managers and botanists with specific involvement, either in managing bitou
bush, or the native species in bitou bush infested areas; 3) rigorous evaluation and examination of
an interim list of species potentially at risk; and 4) ranking the revised list using a model. While,
stage 1 does not differ from previous attempts to determine biodiversity at risk (i.e. Grice et al.
2004; Vidler 2004), stages 2 and 3 outline a new process for rapidly collating information that
would otherwise not be available, and evaluating the quality of that information in order to
determine its integrity, respectively. When the list of species potentially at risk, as produced in
stage 3, is then modelled, i.e. during stage 4, and emphasis is given to the highest priorities, a
robust process for quickly assessing the biodiversity at risk from weed invasions can be
determined without quantitative data (see Downey in press, for further details and discussion).
The outcomes of stages 1 and 2 of the WINS assessment process are not presented here, instead
the final list of species identified as potentially at risk from bitou bush invasion, i.e. the outcome
of Stage 3, is presented in Appendix 3, while the model used for Stage 4 is presented in Appendix
2. The 63 plant species identified in the draft TAP as potentially at risk from bitou bush invasion
using the WINS approach, was expanded to 158 here. The additional 95 species arose from rerunning
various stages of the WINS assessment process. For example, stage 1 included newly
published information (see Coutts-Smith and Downey 2006) along with new threatened species
determinations, while stage 3 involved evaluation and revisions to the list of species at risk as a
result of the comments received during the public exhibition, and in stage 4 most of the 70 species
identified in the draft which were not modelled were added and modelled. Some species identified
as potentially at risk during this process were not modelled however (see Table A3.2).
Irrespective, the changes highlight the flexibility of the WINS assessment process and its value in
rapidly determining species at risk.
The four stage WINS system identified 19 species as being at greatest risk from bitou bush
invasion (i.e. high priority species, see Table 4.1), 41 medium priority and 98 low priority species
(see Appendix 3).
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