National recovery plan for Ginninderra Peppercress (Lepidium ginninderrense)
A Recovery Plan under the Environment Protection and Biodiversity Conservation Act 1999 (C’wlth), based on an Action Plan (Action Plan No. 25) prepared for the species under the Nature Conservation Act 1980 (ACT)
Lepidium ginninderrense is recognised as a threatened species in the following jurisdictions:
Vulnerable: Environment Protection and Biodiversity Conservation Act 1999 (Part 13, Division 1, Subdivision A).
Endangered: Section 21 of the Nature Conservation Act 1980, Disallowable instrument No. 299 of 2001.
Special Protection Status Species: Schedule 7 of the Nature Conservation Act 1980, Disallowable instrument No. 42 of 2002.
The area in which the population of Ginninderra Peppercress occurs is within the Belconnen Naval Transmission Station managed by the Department of Defence (Defence). This communication facility is being de-commissioned with Defence subsequently disposing of the site to the ACT Government. Until disposal occurs, Defence will continue to manage the area including the Ginninderra Peppercress population.
A report prepared for Defence (Resolve FM, HMAS Harman) has provided recommendations aimed at minimising the potential impacts of decommissioning on flora and fauna of the Station site (including impacts on Ginninderra Peppercress) (HLA-Envirosciences Pty Ltd and Cumberland Ecology 2004).
Defence has actively managed the Ginninderra Peppercress population with the assistance of Environment ACT and specialist consultants. The population has been maintained and appears to be expanding its distribution. Management experience suggests that the species is susceptible to overgrazing and to competition from other plant species. Key components of management by Defence have been removal of competitive biomass (by slashing and kangaroo grazing), weed control, and monitoring of kangaroo grazing pressure. It will be important that biomass management continues on the site.
Following disposal by Defence, the main threat to the survival of this population and therefore the species is likely to be urban infill, and deliberate or unintended actions associated with visitor and/or land management activities in the local area. Currently, the fencing around the Transmission Station encloses the area.
Observations by Avis (2000) suggest that the species grows well in locations where competing grass tussocks and other plant growth are short and open, and consequently there is little competition for space and light. Thus, inappropriate management leading to loss of such habitat may also be a threat to the species. It is important to determine management practices that are most conducive to the maintenance of the population at this site.
Removal of infrastructure (masts, concrete anchors, underground wires) as part of the decommissioning of the communication facility has the potential to create major ground disturbance. The population of Ginninderra Peppercress occurs outside the ground-plane of the communication facility that covers a large central area of the Station site. However, the Ginninderra Peppercress site is potentially impacted by the removal of antennae located in that area. Recommendations for removal of these antennae, aimed at minimising impact on the threatened plant population are contained in the fore-mentioned report.
The objectives of the Recovery Plan are to:
- Preserve the existing ACT population of Lepidium ginninderrense as it is the only known population of the species.
- Conserve and manage the habitat of Lepidium ginninderrense so that natural ecological processes continue to operate.