National recovery plan for Zieria formosa, Zieria buxijugum and Zieria parrisiae
NSW National Parks and Wildlife Service, 2002
ISBN 0 731 36496 1
6. Proposed Recovery Objectives, Actions and Performance Criteria for 2001-2005
- Specific Objective 1: Control known threats
- Specific Objective 2: Monitoring
- Specific Objective 3: Determine for each species whether an ex-situ population is required/desirable and if so, establish one.
- Specific Objective 4: Establish medium and long term security for sites containing these species
- Specific Objective 5: Maintenance of an effective liaison between NPWS and the landowners.
The overall objective of this Recovery Plan is to ensure that the adult populations of Z. formosa and Z. buxijugum (reproductive plants >1 m in height) increase to at least those levels recorded by Briggs & Leigh (1990) in the mid 1980s, and that there is a substantial increase (approximately 300%) in the current number of adult plants of Z. parrisiae.
Due to the extremely restricted distribution and small population sizes, it is not envisaged that these species will ever qualify for removal from the Schedules of the TSC or EPBC Act.
Action 1.1: Construct wallaby-proof fences around the three sub-populations of Z. parrisiae.
Due to the extremely low numbers of reproductive Z. parrisiae individuals, all possible measures will be used to increase survival of seedlings and young plants. All the sub-populations have experienced severe browsing by wallabies. It is therefore proposed to construct a wallaby-proof fence around each of the three sub-populations in an effort to reduce this threat. The individual wire mesh guards which were placed around selected Z. parrisiae plants in 1999 will be left in place as additional protection against browsing. Z. formosa seedlings are also occasionally browsed, but currently the impact of this on recruitment does not appear to be significant and there does not appear to be a need to control browsing by native animals.
Performance Criterion 1.1
A wallaby-proof perimeter fence is constructed around each of the three sub-populations of Z. parrisiae within one year of the approval of this Plan.
Action 1.2: Afford, if required, protection to additional selected Z. buxijugum plants using individual wire mesh guards.
Recent heavy browsing by wallabies has had a major impact on Z. buxijugum plants. In April 2001, 10 wire mesh guards were installed to protect from further damage a selection of Zieria plants distributed across the range of the population. This action will allow some plants to flower and produce seed if heavy browsing re-occurs and will increase the potential for future seedling recruitment. If heavy browsing re-occurs at frequent intervals, then it may be necessary to install additional wire mesh guards to protect a larger portion of the population.
Fencing of the whole of the population is desirable, and has been seriously considered. However, because of the very steep, rocky and uneven nature of the terrain in the vicinity of the population, this would be a very difficult and expensive task. This option should be reconsidered if severe browsing proves to be a major ongoing threat which can not be adequately ameliorated through the individual protection (using wire mesh guards) of sufficient reproductive adults.
Performance Criterion 1.2
If monitoring indicates the need, additional individual wire mesh guards are in place within one year of the determination of this need.
Action 2: Establish and maintain a regular monitoring program.
Initially the populations should be monitored every six months to determine mortality and recruitment rates. This monitoring will be used to determine the effectiveness of management actions taken to increase recruitment and survival rates. This is particularly important for Z. parrisiae and Z. buxijugum. Detailed monitoring should be carried out on a number of Z. parrisiae and Z. buxijugum seedlings to determine growth rates, mortality and the likely causes of any loss of plants. As knowledge increases and confidence in management actions improves, monitoring frequency could be reduced to annually.
Performance Criterion 2
A detailed population census is conducted every six months for at least the first two years of this Plan, and subsequently annually for the life of this Plan.
Specific Objective 3: Determine for each species whether an ex-situ population is required/desirable and if so, establish one.
If there is continued decline in the reproductive adult population size of any of these three species despite management efforts, then an expansion of the current ex-situ population should be undertaken. This may be necessary for Z. parrisiae and Z. buxijugum in particular, as the number of adults is currently very low for these species.
Such an ex-situ collection could include both increasing the numbers of live plants and also the establishment of a seed bank An expanded ex-situ collection would serve primarily as a source of propagating material which could then be used in the propagation of plants for reintroduction into the natural site in the event of a catastrophic reduction in the size of the natural population. Such an event is more likely if the natural population, remains very low. An expanded ex-situ population should represent the range of genetic diversity in the wild.
Performance Criterion 3.1
Within three years of the approval of this Plan the need for ex-situ conservation has been assessed.
Action 3.2: If required, establish ex-situ populations and maintain for the purposes of recovery and research.
If the results from Action 3.1 dictate that ex-situ populations are required, then botanical gardens will be approached to establish ex-situ populations from either cuttings or seed. Appropriate locations for any ex-situ populations will also need to be determined.
Performance Criterion 3.2
If determined necessary (Action 3.1), appropriately located ex-situ populations are established within four years.
Action 4.1: Seek agreement from landowners to the establishment of medium and long term protection for all three sites. Implement these protective mechanisms where agreement is reached.
At this time, the continued recovery of these species is subject to the good will of the landowners. Although three of the four landowners have expressed their support for efforts to protect these species, if the land were to change ownership, this situation could change. Measures to ensure the medium term protection of these species could include registering the areas as Wildlife Refuges or entering into a Property Agreement under the provisions of the NVC Act. Long-term protection of these sites could be achieved through Voluntary Conservation Agreements between the owners and NPWS.
Performance Criterion 4.1
Discussions between NPWS and the landholders have been held within five years to seek medium/long term protection of sites from adverse changes in management regimes or from possible adverse developments. Implement these measures within five years where agreement is reached.
Action 4.2: Bega Valley Shire Council to include an advisory note recording the presence of these species on Section 149 Certificates for the relevant properties.
Although the current landowners are aware, and are supportive of the protection of these species on their land, it is important that future potential purchasers of the properties are made aware of the presence of these species at an early stage. Council staff also change over time and it is also important that BVSC is automatically alerted to the presence of these species should any Development Applications be submitted which might affect them. The recording by BVSC of the presence of these species on section 149 Certificates under the provisions of the Local Government Act will assist in achieving this.
Performance Criterion 4.2
Within two years BVSC have recorded the presence of these species on s.149 Certificates for the relevant properties.
Action 4.3: Identification and nomination of Critical Habitat
The NPWS will consider the benefits of nominating Critical Habitat and, if appropriate and after consultation with the landowners, make a recommendation to the Minister regarding what area should be listed.
Performance Criterion 4.3
Within five years NPWS will have made a decision as to whether to recommend to the NSW Minister for the Environment the listing of areas of Critical Habitat for each of the three species.
Action 5: NPWS to maintain regular communication with the landholders
Communications are required on a regular basis (at least twice yearly) to review progress of the recovery program and ensure the landowners are fully informed.
Performance Criterion 5
NPWS is in contact with the landowners at least twice yearly for the life of this Plan.