Spreading Grevillia (Grevillea humifusa) Interim Recovery Plan 2003-2008

Gillian Stack and Val English
Department of Conservation and Land Management, WA, 2003

2. Recovery objective and criteria

Objectives

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

All relevant land managers have been notified of the location and threatened status of the species. The Shire of Dandaragan and the private property owners were formally notified of the presence of Grevillea humifusa populations on their lands in October 1996. The notification details the Declared Rare status of G. humifusa and the associated legal responsibilities.

Declared Rare Flora (DRF) markers have been installed at Population 1. These serve to alert people working in the vicinity to the presence of DRF, and the need to avoid work that may damage vegetation in the area.

The population on private land was fenced in mid 1997 to protect it from grazing by stock and to allow natural habitat to regenerate. Many native species are present, although pasture species do persist.

There have been a number of surveys, but these have not been successful in locating additional populations to date.

Seed was collected in October 1996 and in October 1997 from the only known population, and stored in the Department's Threatened Flora Seed Centre (TFSC). These collections resulted in a combined total of over 1500 seeds being stored at -18°C. Staff of the TFSC test the viability of seed soon after collection and again after one year in storage. The initial viability of these collections ranged from 64% to 92%. After storage for 12 months at -18°C, over 90% germination occurred in both seed lots (unpublished data A. Cochrane ¹), indicating that low temperature and low moisture storage of this species is likely to be successful in the long term. Germinants from these trials are delivered to Botanic Garden and Parks Authority (BGPA) nursery for maturation into full plants.

The BGPA currently have 131 plants of Grevillea humifusa from seven clones, derived from both seed and cuttings. Many of these have been propagated for planting in Kings Park, and will not be retained in the Nursery. Generally they hold up to six plants of each clone in the Nursery (personal communication A. Shade ²). Typically, those individuals planted into the Garden become healthier and more vigorous than those retained in pots in the nursery, and still represent a genetic resource for propagation material for translocation purposes and as ex situ genetic material.

Research into the biology of this species was begun in September 2002. Preliminary work indicates that flowering is more profuse in open areas, but that all plants have low levels of fruit set (personal communication A. Harris). Three 5x5m plots have been established on road reserves and one on private land, within the population. Accurate numbers of plants in plots have been determined. 100 plants within these plots have been permanently marked with metal tags and the plant height, and widths in two dimensions measured. Information collected for 21 of the tagged plants in 2002 also included numbers of flowers, and the success of fruiting.

A double-sided information sheet has been produced, and includes a description of Grevillea humifusa, its habitat, threats, recovery actions and photos. This is being distributed to the local community through libraries, wildflower shows and other avenues. It is hoped that this may result in the discovery of new populations.

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

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 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 G. humifusa 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: $1,000 per year

2. Rehabilitate habitat as necessary

Rehabilitation of G. humifusa habitat could offer long-term protection from weed invasion and buffer extant plants from chemical drift. Population 1b was first cleared in the early 1990s, and has been regenerating well after the stock exclusion fence was erected in mid 1997. Given the natural regeneration occurring at the site, rehabilitation could best be achieved by increasing the rate of establishment of plant species native to the site. Subsequent weed control will enhance this, and smoking of the soil may stimulate additional germination of native species if required. Vegetation dense enough to buffer Grevillea humifusa from windblown weed seed and chemical drift is desirable around the perimeter of the population, but heavy canopy cover is not desirable in a planted buffer as this is likely to reduce vigor and flowering.

Action: Rehabilitate habitat as necessary
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $2,100 in second and fourth years and $1,000 in fifth years.

3 Undertake weed control

Part of the only G. humifusa population exists on a 'retired' paddock, and pasture species persist in addition to other species that have invaded. A number of (mostly grassy) weeds also occur on the road reserve. While adult G. humifusa plants are mostly able to successfully compete with the weeds, the effect on recruitment is a greater threat. Weed control will be undertaken in consultation with the land managers. This will be by hand weeding or localised application of herbicide during the appropriate season to minimise the effect of herbicide on the species and the surrounding native vegetation. 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 G. humifusa and associated native plant species.

Action: Undertake weed control
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $2000 per year

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 (Moora District, WATSCU) through the MDTFRT
Priority: Moderate
Cost: $2000 in the first year

5. Develop guidelines for slashing of habitat

Vegetation at Population 1a requires periodic slashing to maintain visibility for road users. Although this would not result in the cutting of the prostrate G. humifusa, falling leaves and broken branches could smother plants. In addition, if the habitat deteriorates, weed invasion may increase and become a threat to G. humifusa plants and seedlings. Guidelines will be developed to prescribe methods of carrying out this necessary road maintenance that will minimise the damage caused to G. humifusa and its habitat.

Action: Develop guidelines for slashing habitat
Responsibility: The Department (Moora District), Roadside Conservation Committee, Shire of Dandaragan through the MDTFRT
Cost: $1,000 in first year

6. Undertake rabbit control

Rabbits appear to occur in large numbers in the area and there is evidence of rabbit grazing in the habitat of Grevillea humifusa (personal communication A. Harris). Although the adult plants are coping with the current level of grazing, the effect on recruitment is likely to be more severe. Rabbits will be controlled, using 1080 oats if appropriate, in consultation with relevant landholders.

Action: Undertake rabbit control
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $300 per year

7. Develop and implement a fire management strategy

A fire management strategy will be developed by the Department's Moora District in consultation with relevant land managers (including the private property managers at Population 1, the Shire of Dandaragan and adjacent landholders) and the Moora District Threatened Flora Recovery Team. The species' response to fire will be taken into account when developing this strategy, which will include recommendations on fire frequency, intensity, and methods of fire control. The information will then be passed on to relevant bodies, including the Bush Fire Brigade.

Action: Develop and implement a fire management strategy
Responsibility: The Department (Moora District), relevant land managers through the MDTFRT
Cost: $900 in first year and $700 in subsequent years

8. Seek long-term protection of habitat

Staff from the Department's Moora District will continue to liaise with land managers and landowners to ensure that populations are not accidentally damaged or destroyed. In addition, ways and means of improving the security of the population and its habitat will be investigated. This may include conservation covenants with a range of agencies, the Land for Wildlife scheme, and possibly land acquisition.

Action: Seek long-term protection of habitat
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,000 in first year and $500 per year in subsequent years

9. Monitor population

Annual monitoring of factors such as habitat degradation (including weed invasion, salinity and plant diseases such as Phytophthora cinnamomi), population stability (expansion or decline), pollination activity, seed production, recruitment, longevity and predation is essential. For Population 1a on a road reserve, the visibility of DRF markers will also be monitored and maintained.

Action: Monitor population
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,000 per year

10. Conduct further surveys

Community volunteers will be encouraged to be involved in further surveys supervised by Departmental staff that will be conducted during the flowering period of the species (June to September). Suggested survey locations include the Hill River Nature Reserve and the area around the Jurien Bay - Watheroo turnoff.

Action: Conduct further surveys
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,500 per year in first, third and fifth years

11. Collect germplasm

Preservation of germplasm is essential to guard against extinction if wild populations are lost. Such collections are also needed to propagate plants for translocations. Approximately 1500 seeds have already been collected from Population 1 but further collections are required to ensure sufficient material is available for propagation of translocates as well as maintaining a collection in storage.

Action: Collect germplasm
Responsibility: The Department (TFSC, Moora District) through the MDTFRT
Cost: $1,500 per year

12. Undertake and monitor translocation

Translocation is essential for the conservation of this species, as the population is not secure from threats including weed competition, grazing, fire and physical destruction, and the single location means the species is vulnerable to extinction from a single catastrophic event. A translocation proposal will be developed and suitable translocation sites selected. Plants will also be propagated in readiness for translocation, and when appropriate, these will be planted in accordance with the approved Translocation Proposal. This will be coordinated by the MDTFRT. 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. All Translocation Proposals require endorsement by the Department's Director of Nature Conservation.

Monitoring of the translocation is essential and will be undertaken according to the timetable developed for the Translocation Proposal.

Action: Undertake and monitor translocation
Responsibility: The Department (Moora District, TFSC) and BGPA through the MDTFRT
Cost: $11,000 in the second year and $7,500 in subsequent years

13. Promote awareness

The importance of biodiversity conservation and the need for the long-term protection of wild populations of this species will continue to 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. An information sheet has been produced, and contains a description of the plant, its habitat, threats, recovery actions and photos. This will continue to be distributed to the public through the Department's Moora District office, and at the office and library of the Shire of Dandaragan. Staff of the Moora District will also work with local Community Support Officers towards increasing awareness of the species.

Action: Promote awareness
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $500 per year

14. Obtain biological and ecological information

Improved knowledge of the biology and ecology of G. humifusa will provide a better scientific basis for its management in the wild. Research has already begun, and information will continue to be gathered on the following aspects of the biology of the species.

  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 herbicide on G. humifusa and its habitat.

Much of this information will be obtained through bi-annual monitoring of numbers of plants in permanently established plots, by measuring growth rates, flowering, and fruiting success for tagged plants in plots.

Action: Obtain biological and ecological information
Responsibility: The Department (Science Division, Moora District) through the MDTFRT
Cost: $18,000 per year in the second, third and fourth years

15. 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, Moora District) through the MDTFRT
Cost: $20,300 in the fifth year (if full Recovery Plan required)