Abba Bell (Darwinia sp. Williamson) interim recovery plan 2003-2008

Interim recovery plan no. 139
Gillian Stack & Val English
Department of Conservation and Land Management, Western Australia, 2003

2. Recovery objective and criteria


The objective of this Interim Recovery Plan is to abate identified threats and maintain or enhance 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

The Department of Minerals and Energy was formally notified of the presence of Darwinia sp. Williamson in October 1996. The adjacent private property owners were notified in February 1999. These notifications detailed the Declared Rare status of the species and associated legal obligations. The mining company with a tenement over this area was notified of the presence of two other Critically Endangered species (Petrophile latericola and Brachysema papilio) in October 1994, and of the occurrence of Darwinia sp. Williamson in June 1999.

Liaison with these stakeholders is ongoing. The area is still under a Mineral Lease. Approval to mine Location 4102 adjacent to the wild population was granted in 2002. Liaison between the proponent, the Department and relevant government bodies is ongoing. Potential impacts include major modification of the hydrology of the area, and the proponent has installed an artificial recharge system to maintain the water levels at the site, and several piezometers for monitoring purposes, together with programmes for monitoring vegetation health and some funds for general maintenance of the TEC and component threatened flora.

In addition to previous purchases of ironstone habitat, two areas of this habitat type on private property were purchased by the Department in 1999. Although degraded through previous clearing for agriculture, the new sites contain the ironstone soil type. Both parcels of land are being used for a suite of translocations of five critically endangered ironstone species, and are also being rehabilitated with common local provenance species. Population 2T is north of the wild population of Darwinia sp. Williamson, and has been protected with rabbit-proof fencing. Population 3T of Darwinia sp. Williamson is to the north east of Population 1, and has been fenced to exclude kangaroo and rabbit grazing. Both are now A Class Nature Reserves for the purpose of conservation of flora and fauna. The purchase of another area of private property adjoining one of the new Nature Reserves is also in progress, further extending the area of remnant vegetation to act as a buffer, and a potential site for future translocations.

A total of approximately 360 seeds (from 879 fruits) are currently stored in the Department's Threatened Flora Seed Centre (TFSC) at -18°C. These were collected in December 1995 and December 1997. Staff of the TFSC test the viability of seed soon after collection and again after one year in storage. The initial germination rate of Darwinia sp. Williamson seed ranged from 60 to 86%. After one year in storage the germination rate was 31% (unpublished data A. Cochrane). Additional seed was collected in 2002, but this has not yet been processed.

The Botanic Garden and Parks Authority (BGPA) currently have eleven living plants of Darwinia sp. Williamson from three clones. Cuttings of this species do very well, with strike rates generally above 50% and often as much as 90% (personal communication A. Shade).

A Translocation Proposal as required under the Department's Policy Statement Number 29 was approved for this species in 2001. 422 plants were propagated by BGPA from seed and cuttings, and translocated into the two previously mentioned Nature Reserve sites in July 2001. 354 plants were introduced to an area of ironstone north of the wild population (Population 2T), and 68 more to a second area north east of the wild population (Population 3T). Different treatments being trialled include ripping and mounding, mounding, watering and shading. Control sites were also established. Survival of the 2001 plantings was poor, with only 14% still alive six months after planting at Population 2T, and 47% at Population 3T. Problems with rabbits, weeds, strong winds and inundation, followed by a longer than average summer drought, have all contributed to plant deaths with initial survival overall being poor. Watering systems have been set up at both sites, weed and rabbit control is continuing and windbreaks were planned for planting in 2002 in a bid to reduce the number of plant deaths.

An additional 6 translocates were planted in Population 2T in 2002. Windbreaks were planted using plants grown from local provenance material and further plantings of associated species are planned for 2003. It is anticipated that further translocations of the species will occur in 2004.

Disease hygiene measures are implemented during all operations. This includes limiting vehicle access to tracks, and cleaning all tools used on one plant before using on another, such as secateurs when taking cuttings, and when using spades and other tools used during translocations. Bollards were installed across the main access track into the wild population in 1999, to prevent vehicle access at all times.

Samples were taken from the habitat of the wild population by the Department's Science Division in May 1997 to assess the presence or absence of Phytopthora spp. These positively identified P. cinnamomi. Dieback disease (caused by Phytophthora cinnamomi) is evident at the site with deaths of susceptible species, including Lambertia echinata subsp. occidentalis. Research conducted between 1992 and 1997 indicates that phosphite application is a very effective tool in controlling the impact of dieback disease (Murray 1997). Population 1, within a State Forest Block, has been sprayed up to three times per year since 1996. A phosphite monitoring program was established in 1998, and is ongoing. This involves the monitoring of floristic plots by checking plant health of a number of tagged plants and recording changes over time. Photographic records are also kept for comparison. Recent monitoring suggests that annual spraying of phosphite may be too frequent for some associated species, leading to phyto-toxicity ('burning' of foliage). Modifications may be required to the schedule of spraying as the program continues. The susceptibility of Darwinia sp. Williamson to the disease is currently under investigation.

Phytophthora spp. were also implicated in the deaths of translocates at Population 2T. P. cinnamomi was recorded from roots and soil, while P. cryptogea was also isolated from soil in early 2002. Both translocated populations were also treated with phosphite in 2002.

A coordinated fire response plan for the species has been developed and incorporated into the Fire Control Working Plan. This includes strategies for fire control at each location of the taxon, including translocation sites. The information will also be communicated to other fire response organisations.

In 2001, invasive weeds were controlled by hand around Darwinia sp. Williamson in Populations 2T and 3T by both volunteers and Department staff. The entire paddock section of Population 2T had herbicide applied via a blanket wiper mounted on a four-wheel motorbike to control Guilford grass (Romulea sp.), which was very effective. The remaining weed species are mostly annuals which will be controlled by application of herbicide and slashing as required. The aim is to eventually smother the weed species with native vegetation.

The fence surrounding Population 2T was observed to have rusted in some sections in 2001. Rabbit activity was also observed. Repairs have been effected and 1080 poisoned oats, gassing and shooting have all been used to reduce the number of rabbits. However, they continue to threaten the translocates and rabbit control methods will continue. A rabbit and kangaroo proof fence was erected at population 2T (Negus) in 2002.

Implementation of the recovery actions outlined in the IRP for the community ‘Shrublands on southern Swan Coastal Plain Ironstones’ (English 1999) has commenced, and recovery actions that benefit the TEC habitat will also benefit Darwinia sp. Williamson.

A double-sided information sheet has been produced, and includes a description of Darwinia sp. Williamson, its habitat, threats, recovery actions and photos. This will be distributed to community members through local libraries, wildflower shows and other events, and is available for download on the internet

A brochure about the values of Abba Plains vegetation has also been produced by local catchment group Geocatch with Departmental assistance, in support of landholders protecting their remnant vegetation. This includes details of the ‘Shrublands on southern Swan Coastal Plain Ironstones’ threatened ecological community and photos of Darwinia sp. Williamson and other key species. It is hoped that these may result in the discovery of new populations. A threatened flora display was presented during a recent Busselton Wildflower Show.

Staff from the Department's Blackwood District have developed a map delineating the areas not available for commercial wildflower picking to help ensure that pickers do not enter the area in which Darwinia sp. Williamson occurs.

Staff from the Department's Blackwood District regularly monitor the wild and translocated populations of this taxon. Monitoring includes recording changes in weed levels, the impacts of Phytophthora cinnamomi and other plant diseases, grazing activity, fire, fencing and other types of disturbance.

The South West Region Threatened Flora Recovery Team (SWRTFRT) 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 appropriate land managers prior to recovery actions being undertaken.

1. Coordinate recovery actions

The SWRTFRT will continue to coordinate the implementation of recovery actions for Darwinia sp. Williamson 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 (Blackwood District) through the SWRTFRT
Cost: $6,200 per year

2. Maintain disease hygiene

The ironstone habitat in which Darwinia sp. Williamson occurs is inundated over the winter months, and this favours the establishment and spread of Phytophthora species. Many plant species in the ironstone community are presumed to be susceptible to this disease, including Darwinia sp. Williamson. Dieback hygiene (outlined in Department of Conservation and Land Management 1992) will therefore be adhered to for activities such as installation and maintenance of firebreaks and walking into the population in wet soil conditions. Purpose built signs advising of the dieback risk and high conservation values of this site will be installed.

Action: Maintain disease hygiene
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $600 per year

3. Continue Phytophthora control

Aerial spraying of phosphite has occurred over the community that contains Darwinia sp. Williamson. This action helps to protect the TEC, and the other endangered flora that occur in that community (a number of which are also Critically Endangered) from dieback disease. This action will continue to be implemented as necessary.

The impact of the phosphite application on this taxon and its habitat will continue to be monitored, and this will also indicate the requirement for follow-up treatment.

Action: Continue Phytophthora control
Responsibility: The Department (Blackwood District, Dieback Disease Coordinator) through SWRTFRT
Cost: $3,800 in the first, third and fifth years, plus $500 per year for monitoring

4. 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 (Blackwood District, WATSCU) through the SWRTFRT Cost: $2000 in the first year

5. Implement the fire management strategy

It is known that fire kills most adult plants of the species and regeneration is largely from seed. However, frequent fire may prevent the accumulation of sufficient soil-stored seed for recruitment to occur. Fire should therefore be prevented from occurring in the area of populations, except where it is being used experimentally as a recovery tool. A fire response plan has been developed for both the wild and translocated populations and incorporated into the Blackwood District's Fire Control Working Plan. Other fire fighting agencies will be informed of appropriate responses to fire threatening this site. Firebreaks will continue to be maintained.

Action: Implement the fire management strategy
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $1000 per year

6. Continue the translocation process

Translocation is essential for the conservation of this species, as the single small wild population is not secure from threats including disease, inappropriate fire regimes, mineral exploration or extraction, waterlogging and salinity. Information on the translocation of threatened plants and animals in the wild is provided in the Department's Policy Statement No. 29 Translocation of Threatened Flora and Fauna. This recovery action will continue to be coordinated by the SWRTFRT.

A Translocation Proposal has been developed and was endorsed by the Department's Director of Nature Conservation. The translocation will involve two sites, introducing the species into two areas of suitable habitat recently acquired as Nature Reserves.

The propagation of plants for translocation has been undertaken and will continue as necessary. Plantings have occurred in 2001 and 2002. Additional plantings will occur as necessary in accordance with the approved Translocation Proposal. Monitoring of the translocation is essential, and will continue to be done according to the timetable developed for the Translocation Proposal.

Action: Continue the translocation process
Responsibility: The Department (Blackwood District, Science Division, TFSC), BGPA through SWRTFRT
Cost: $10,500 per year ($5,500 for monitoring, $2,000 for propagation, $3,000 for planting)

7. Liaise with land managers

Staff from the Department's Blackwood District will continue to liaise with the mining tenement holder and adjacent land managers to ensure that neither wild nor translocated populations are accidentally damaged or destroyed. In particular, the results of monitoring of the impacts of the mine that will occur immediately adjacent to the species are to be promptly communicated to the Department, and appropriate responses made.

Action: Liaise with land managers
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $500 per year

8. Monitor populations

Factors such as habitat degradation (including weed invasion, salinity and plant diseases such as Phytophthora cinnamomi), groundwater quality and levels, population stability (expansion or decline), pollination activity, seed production, recruitment, longevity and predation will be monitored annually for both wild and translocated populations.

Action: Monitor populations
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $500 per year

9. Continue weed control

Weed levels at the wild population is low;, however, at the translocated sites the level of weed invasion is high and ongoing control is necessary. Remaining weeds are mostly annuals, and weed control will be by hand weeding or localised application of herbicide during the appropriate season to minimise the effect of herbicide on the species and any associated native vegetation. Because of the increasing difficulties in using chemicals and slashing within the translocation sites due to proximity to regenerating seedlings, trials will be undertaken to compare the effects of smothering weeds by mulch, jute matting and no treatment. All applications of weed control will be followed by a report on the method, timing and success of the treatment against weeds, and the effect on Darwinia sp. Williamson and associated native plant species.

Action: Continue weed control
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $500 per year

10. Control grazing

As a consequence of some previous control, the current level of threat from rabbits is moderate at the translocated populations. Populations 2T and 3T have been fenced with rabbit-proof fencing to protect the translocates from grazing. However, rabbits continue to impact on populations through grazing and digging, and they will continue to be controlled using a variety of methods as appropriate, in consultation with relevant landholders. Fencing has also been undertaken to exclude kangaroo grazing at population 3T.

Action: Control grazing
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $200 per year

11. Conduct further surveys

Although this community type has been extensively surveyed over the last decade, it is possible that additional populations of this or other ironstone species may be discovered,. Surveys will particularly target remnant vegetation of this type on private lands as permission is obtained. It is likely, however, that these occurrences would be affected by agricultural clearing and grazing. Community volunteers will be encouraged to be involved in further surveys by Departmental staff to be conducted during the flowering period of the species (October).

Action: Conduct further surveys
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $2,500 per year

12. Collect seed and cutting material

Preservation of germplasm is essential to guard against extinction if wild populations are lost. Such collections are also needed to propagate plants for translocations. A small quantity of seed and cuttings has been collected from Population 1 but further collections are required. In addition, collections from the translocated populations will be made when possible.

Action: Collect seed and cutting material Responsibility: The Department (TFSC, Blackwood District) and BGPA, through the SWRTFRT Cost: $2,800 in the second and fourth years

13. Obtain biological and ecological information

Increased knowledge of the biology and ecology of Darwinia sp. Williamson will provide a better scientific basis for its management in the wild. An understanding of the following is particularly necessary for effective management:

  1. Soil seed bank dynamics and the role of various disturbances (including fire), competition, rainfall and grazing in germination and recruitment.
  2. The pollination biology of the species.
  3. The requirements of pollinators.
  4. The reproductive strategies, phenology and seasonal growth of the species.
  5. The population genetic structure, levels of genetic diversity and minimum viable population size.
  6. The impact of dieback disease and control techniques on Darwinia sp. Williamson and its habitat.
  7. The impact of changes in hydrology on Darwinia sp. Williamson and its habitat.

Action: Obtain biological and ecological information
Responsibility: The Department (Science Division, Blackwood District) through the SWRTFRT
Cost: $17,200 per year in the second, third and fourth years

14. Stimulate the germination of soil-stored seed

Burning, smoke water and soil disturbance are likely to be effective in stimulating the germination of soil-stored seed. These trials will be conducted as appropriate at the base of dead mature plants.

Action: Stimulate the germination of soil-stored seed
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $200 in second and fourth years

15. Promote awareness

The importance of biodiversity conservation and the need for the long-term protection of wild populations of this species will be promoted to the community through poster displays and the local print and electronic media. Formal links with local naturalist groups and interested individuals will also be encouraged.

Action: Promote awareness
Responsibility: The Department (Blackwood District) through the SWRTFRT
Cost: $600 per year

16. Review the need for a full Recovery Plan

At the end of the fourth year of its five-year term this Interim Recovery Plan will be reviewed and the need for further recovery actions will be assessed. If the species is still ranked as Critically Endangered at that time a full Recovery Plan may be required.

Action: Review the need for further recovery actions and/or a full Recovery Plan
Responsibility: The Department (WATSCU, Blackwood District) through the SWRTFRT
Cost: $20,300 in the fifth year (if full Recovery Plan required)