National recovery plan for the Downy Wattle (Acacia pubescens)
NSW National Parks and Wildlife Service
Environment Australia, February 2003
ISBN 0 7313 6504 6
It is clear from the information in this Recovery Plan that studies of the genetic variability of A. pubescens will be essential for management of the species. There is also clearly a lack of other information on the biology, ecology and distribution of the species. Long-term management of A. pubescens will be based on sound principles once there is a better understanding of the biology and ecology of these aspects.
To understand the biology, ecology, health and distribution of the species including the range of genetic variation.
A research program to investigate currently unknown aspects of biology, ecology, health and distribution is implemented and this information is used in management of the species.
Preliminary studies of the genetic diversity of A. pubescens have been carried out at 10 sites of the species (Mountain Lagoon, Carysfield Park, Louisa Reserve, Rookwood Cemetery, Scheyville National Park, Prospect Reservoir, Menai, Yennora Wool Centre, Salter Rd Reserve and Weeroona Rd). The results of these studies indicate that the species is an extensively clonal species, and the number of individuals at sites is low (Moore et al. 1999). More sites should be sampled to confirm these results and to determine which sites should be priorities for conservation. The results of genetic studies should be examined in combination with studies into the breeding system of A. pubescens , to determine if an interaction is occurring between clonality and self-incompatibility to limit seed set, or whether pollination or resources is limiting seed set (Moore et al. 1999). This information will also allow identification and mapping of 'habitat which is critical to the survival of the species' as per section 270(2)(d) of the EPBC Act 1999 (Cth).
The large number of individuals that appear to be suffering from an unknown plant disease which affects the leaves of plants, is potentially a large threat to the species. A survey should be undertaken at a number of sites to determine the nature and extent of the disease. This action should be undertaken by an appropriate institution that is involved in plant disease research. The NPWS will seek tenders for this research.
Investigations should be directed towards the following areas:
- Population dynamics:
The degree of tolerance of A. pubescens to disturbance needs to be investigated. The species may require a certain amount of disturbance for recruitment. The proportion of recruitment by vegetative reproduction, relative to seed germination, should be investigated. This will allow predictions to be made about the genetic variability of populations over time.
- Breeding System:
There are many aspects of the breeding system that require investigation, such as the cause of the low seed set, whether there is any variation between individuals in relation to fruit production, the seed viability and whether there is any variation in seed viability relative to the age of the individual. These studies should be undertaken over a number of years so that it can be established whether environmental conditions are leading to variation in fruiting and seeding rates.
- Fire ecology:
The optimal fire characteristics of the species needs to be determined, in regard to fire frequency, intensity, duration and seasonality. The effects of fire on recruitment, establishment and survival need to be established. The tolerance of stems to fire should also be investigated. Once an optimal fire regime is established, fire management plans for sites should be developed. This information will also be important in determining the chances of survival of the species at sites that are prone to arson.
Mechanical damage is listed as one of the threats to A. pubescens . Damage often occurs simply from a lack of awareness about the presence of the species at a site. The incidence of this threat could be reduced if relevant landowners were made aware of the presence of A. pubescens . Councils should be aware of all sites of A. pubescens in their LGA, given their roles as consent authorities and land managers.
The NPWS will encourage Councils to undertake surveys in their areas, so that the complete distribution of the species can be established. The NPWS will also encourage Councils to modify the section 149 Certificates of relevant properties to include a notice about the presence of A. pubescens , to increase knowledge of the species' presence.
The NPWS will encourage universities, other research institutions and trained members of the community to take part in these research programs. The NPWS will be responsible for the co-ordination of research programs and dissemination of results.