Threatened species & ecological communities

Blunt wattle (Acacia aprica) Interim Recovery Plan 2003-2008

Interim Recovery Plan No. 152
Ben Bayliss
Department of Conservation and Land Management, WA, 2003

2. Recovery objective and criteria

Objective

The objective of this Interim Recovery Plan is to abate identified threats and maintain viable in situ populations to ensure the long-term preservation of the species in the wild.

Criteria for success: The number of individuals within populations and/or the number of populations have increased by ten percent or more.
Criteria for failure: The number of individuals within populations and/or the number of populations have decreased by ten percent or more.

3. Recovery actions

Existing recovery actions

All appropriate agencies and land managers have been made aware of the existence of Acacia aprica and its locations on land under their jurisdiction.

Declared Rare Flora (DRF) markers have been installed at all road and rail reserve populations.

The Shire of Coorow and Main Roads Western Australia (MRWA) were formally notified of the presence of populations of A. aprica on lands they managed in January 1998. These notifications detailed the Declared Rare status of the species and associated legal obligations. The Shire of Coorow was provided with a map and verbal description of the location of markers installed on their road reserves and MRWA personnel were present at the installation of markers at Populations 1 and 2. The owner of land on which Population 6 occurs received notification in February 1999 and agreed to take care near the single plant of Acacia aprica when maintaining the nearby firebreak on this property.

Declared Rare Flora (DRF) markers were installed at Populations 3 and 5 in July 1998, and at Populations 1 and 2 in December 1998. DRF markers alert people working in the area to the presence of significant flora. This helps to prevent accidental damage during maintenance operations. Markers at Population 3 were repositioned in August 2000 to include additional plants located through subsequent surveys. A new population (number 9) of seven individuals was identified in August 2002 by officers of the Department and several plants close to the road noted as being vulnerable to damage from road works. DRF markers were installed and the Coorow Shire Council notified. In February 2003 DRF markers for Population 4 were installed to include the two plants comprising Population 4b. The single very old plant at Population 4 is located against a fence, and is far enough from the road edge to be protected from roadside grading.

Owners of the vegetation remnant that contains Population 7 were notified of the presence of Acacia aprica in February 2000 and the particular significance of this site for conservation of the species highlighted. An agreement has been reached between the owner and the Department to re-fence the area. Materials have been made available to assist the landowner to carry out the required works. The owners have expressed an interest in this species, and permitted future access for monitoring and research.

Awareness of the significance of DRF markers is being promoted to relevant authorities such as Shires, Main Roads WA, Westnet Rail and Fire and Emergency Services Authority. Dashboard stickers, information sheets and drink holders have also been produced and distributed. These illustrate DRF markers, inform of their purpose and provide a contact telephone number to use if such a marker is encountered.

In 1998 a translocation programme was commenced to address the significant immediate threats posed to the species from the low number of plants and high degree of habitat fragmentation. Initial trials were carried out by direct seeding in August 1998 and were conducted on an experimental basis, with the aim of providing information about effective techniques for future translocations. Seed was collected from one population and several plants cultivated by the Botanic Gardens and Parks Authority (BGPA). No seedlings were found when the direct seeding trial was examined in December 1998. However it was subsequently noted that 76 seeds had germinated of which 52 were still surviving as seedlings in 2001. Two further experimental translocations took place in 1999 and 2000 with seedling stock raised by BGPA from germinants supplied by the Department's Threatened Flora Seed Centre (TFSC). These translocations were subject to several experimental treatments assessing the effectiveness of establishment methods. The surviving plants have been monitored annually.

In 1999 a three year study assessing limitations on population growth of two rare acacias including Acacia aprica was undertaken (Yates and Broadhurst 2002). As part of this study, in 2000 seed was sown on trial plots adjacent to two natural populations to assess the impact of invasive weeds and grazing on seedling establishment. The emergent seedlings were monitored from 1999 to 2001. Surviving plants from the translocation trials and ecological study plots continue to be assessed as part of the regular programme of monitoring for all the natural populations.

897 seeds were collected from 30 plants during November 1996 and approximately 20,000 from 60 plants in Population 1 in 1997. These collections were stored at -18°C in the Department's TFSC. The TFSC test the viability of the seed initially, after one year in storage, and again within 5 - 6 years. Germination rates ranged from 43% to 85%, with the higher rates reflecting additional seed coat treatments applied prior to the first year storage test. Currently no living plants are held by Botanic Gardens and Parks Authority (BGPA), however a subset of seedlots collected by the TFSC is maintained at the BGPA.

Three phases of translocation trials have been carried out. Survival and mean height data have been collected to assess the following methods:

  1. 1998, direct seeding, with watering and mulching
  2. 1999, planting of seedlings, with mulching.
  3. 2000, planting of seedlings, with grazing exclusion fencing.

In addition comparative data have been collected to assess phenology, flowering intensity, fruit and seed production for natural and translocated populations of Acacia aprica. Currently there are 388 surviving plants in translocated populations.

Staff from the Department's Moora District regularly monitor populations.

A poster illustrating all critically endangered flora taxa in Moora District has been prepared for display at Shire offices and shopping centres. An information sheet for Acacia aprica has also been produced with photographs, a description of the plant, its habitat type, threats and management actions.

The Moora District Threatened Flora Recovery Team (MDTFRT) is overseeing the implementation of this IRP and will include information on progress in its annual report to the Department's Corporate Executive and funding bodies.

Future recovery actions

Where populations occur on lands other than those managed by the Department, permission has been or will be sought from the appropriate land managers prior to recovery actions being undertaken.

1. Coordinate recovery actions

The Moora District Threatened Flora Recovery Team (MDTFRT) will coordinate recovery actions for Acacia aprica and other Declared Rare Flora in the region. They will include information on progress in their annual report to the Department's Corporate Executive and funding bodies.

Action: Coordinate recovery actions
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1000 per year

2. Map Critical habitat

It is a requirement of the EPBC Act that spatial data relating to critical habitat be determined. Although critical habitat is described in Section 1, the areas as described have not yet been mapped and that will be done under this action. If any additional populations are located, then critical habitat will also be determined and mapped for these locations.

Action: Map critical habitat
Responsibility: The Department (Moora District, WATSCU) through the MDTFRT
Cost: $2000 in the first year

3. Implement weed control

With the exception of Population 7 all populations are severely weed infested. Adult Acacia aprica plants are currently surviving competition from weeds, however the effect on subsequent recruitment presents a greater potential threat. Weed control with the use of herbicides will be undertaken for all populations. The tolerance of native plant species to herbicides at Acacia aprica sites is unknown, so the impact of herbicides will be monitored. A weed control program for these populations is required and will involve:

  1. Accurately mapping the boundaries of the weed populations.
  2. Selection of an appropriate herbicide or alternative method of weed control after determining which weeds are present.
  3. Controlling invasive weeds internal to the boundary of the Acacia aprica population by hand removal and spot spraying around individual Acacia aprica plants when weeds first emerge.
  4. Scheduling to include weed spraying of other Declared Rare Flora populations requiring weed control within Moora District.
  5. Any incidental disturbance activities within or around Acacia aprica populations, particularly where there is the potential for stimulating germination, will be monitored for weed incursions and appropriate control measures taken to enhance natural recruitment of Acacia aprica.
  6. Any approved programme of controlled experimental or ameliorative disturbance such as fire in or around populations of Acacia aprica will include a post disturbance weed management strategy.

Action: Implement weed control
Responsibility: The Department (Moora District) through the MDTFRT, relevant land managers
Cost: $1000 per year.

4. Continue to implement approved Translocation Proposal

Subsequent to the initial translocation of Acacia aprica by direct seeding, approval was given for the planting of seedling stock. New translocation sites will be sought to increase the number of established populations, and to continue to refine establishment methods. In addition, if possible, further seed will be collected and used in translocations to ensure that material used is from a wider range of populations.

Translocations will continue to be monitored until it can be determined that the translocations represent viable self-sustaining populations.

Action: Continue to implement approved Translocation Proposal
Responsibility: The Department (Science Division, Moora District) through the MDTFRT
Cost: $5000 per year for Year 1, 2 and 3

5. Attempt to stimulate germination

Attempts will be made to stimulate germination of soil-stored seed in areas adjacent to extant A. aprica ms populations. This will involve experimental treatments that may include burning, smoke treatment and/or ground raking. It is hoped that this will result in improved habitat through encouraging regeneration of associated native species as well as Acacia aprica. Weed control will be undertaken as part of this recovery action, as any disturbance will also stimulate weed germination. The results of all trials will be monitored regularly.

Action: Attempt to stimulate germination
Responsibility: The Department (Science Division, Moora District) through the MDTFRT
Cost: $3,000 for the first year, $2,000 per year for the second and third years, $500 for the fourth and fifth years

6. Monitor populations

Monitoring factors such as weed densities, habitat degradation, population stability (expansion or decline), pollination activity, seed production, recruitment and longevity is essential. For Populations 1, 2, 3, 4, 4a, 5, and 9 DRF markers will also be monitored annually for visual prominence eg: where subject to weathering, or obscuring vegetation, such that they remain visible and effective.

Action: Monitor populations
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,600 per year.

7. Implement fire management strategy

Little is known about the effects of fire on this species. It is likely that the species requires occasional fire for recruitment from soil-stored seed, but frequent fires may be detrimental to the long-term survival of the species. Fire also promotes the introduction and proliferation of weed species.

A fire management strategy has been developed in consultation with relevant land managers. The strategy takes into account current information about factors including soil seed banks and modes of reproduction, and recommends exclusion of fire except when required to stimulate regeneration, and also specifies fire control methods. This plan will be implemented, and amended as required as additional information becomes available.

Action: Implement fire management strategy
Responsibility: The Department (Moora District) through the MDTFRT, relevant land managers
Cost: $1,000 per year.

8. Obtain biological and ecological information

Increased knowledge of the biology and ecology of the species will provide a scientific basis for management of Acacia aprica in the wild. Initial work by Yates and Broadhurst (2002) has greatly improved knowledge of the species. Future investigations will include:

  1. Further study of the soil seed bank dynamics, including seedbank location and viability.
  2. The role of various factors such as, competition, rainfall, grazing, disturbance, seedling recruitment and survival, particularly in relation to the enhancement and maintenance of the species regeneration niche.
  3. Determination of reproductive strategies, phenology and seasonal growth.
  4. Investigation of the mating system and pollination biology.
  5. Investigation of population genetic structure, levels of genetic diversity and minimum viable population size.
  6. Investigation of the impacts of herbicide on habitat

Action: Obtain biological and ecological information
Responsibility: The Department (Science Division, Moora District) through the MDTFRT
Cost: $17,000 in the second year.

9. Collect seed and cutting material

It is necessary to store germplasm as a genetic resource, ready for use in translocations and as an ex situ genetic 'blueprint' of the species. The germplasm stored will include seed and live plants in cultivation. A quantity of seed has been collected from Population 1. However, some of this has been used for translocations and ecological research trials. Further collection is necessary to maintain adequate representation of the remaining genetic diversity of this taxon.

Action: Collect seed and cutting material
Responsibility: The Department (TFSC, Moora District), BGPA, through the MDTFRT
Cost: $2,000 in the second and fourth years.

10. Conduct further surveys

Further survey for the species will be undertaken during the species' flowering period (June-August) on a systematic basis in areas of suitable habitat. Volunteers from the local community, Wildflower Societies, Naturalist Clubs, other community-based groups and tertiary students will be encouraged to be involved in surveys supervised by Departmental staff.

Suggested survey locations include the Pinjarrega Nature Reserve, where the similar taxon, A. filifolia, occurs.

Action: Conduct further surveys
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $2,300 per year.

11. Promote awareness

The importance of biodiversity conservation, the preservation of critically endangered species generally and Acacia aprica in particular will be promoted to the public. Awareness will be encouraged in the community through a publicity campaign using the local print and electronic media and poster displays. Formal links with local naturalist groups and interested individuals will also be encouraged. An information sheet that includes a description of the plant, its habitat, threats, management actions, and photos has been produced. This will continue to be distributed to the public through the Department's Moora District office and at the offices and libraries of the Shires of Coorow and Carnamah. Such activities may lead to the discovery of new populations.

Action: Promote awareness
Responsibility: The Department (Moora District, Corporate Relations Division) through the MDTFRT
Cost: $500 per year.

12. Review the need for a full Recovery Plan

This Interim Recovery Plan will operate from June 2003 to May 2008, when it will be reviewed, but will remain in force until withdrawn or replaced. If the species is ranked as Critically Endangered at that time a full Recovery Plan may be required.

Action: Review the need for a full Recovery Plan Responsibility: The Department (Moora District) through the MDTFRT Cost: $10,000 in the fifth year.

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