Green Hill Thomasia (Thomasia sp. Green Hill) Interim Recovery Plan 2003-2008

Interim Recovery Plan No. 132
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

The landowner was made aware of the existence and importance of Thomasia sp. Green Hill in 1995. Since then, the Farm Manager has participated in a survey for further populations and assisted subsequent Departmental staff in locating the known subpopulations. Care is also being taken in the management of the bush block to conserve the two subpopulations of Thomasia sp. Green Hill. A letter was sent to notify the landowner in October 1996 when the species was formally gazetted as Declared Rare Flora.

Due to the proximity of the subpopulations to crops on adjacent land, the managers of that land have been informed of the location of Thomasia sp. Green Hill. This is to ensure that due care is taken to avoid chemical drift and leaching, and to ensure maintenance of the fence is adequate to exclude stock.

Seed was collected from both subpopulations twice in November 1998 and stored in the Department's Threatened Flora Seed Centre (TFSC). The TFSC holds 106 seeds from 17 plants from Population 1a and 130 seeds from 45 plants at Population 1b. Staff of the TFSC test the viability of seed soon after collection and again after one year in storage. The initial germination rate of this seed ranged from 20% to 40%. After one year in storage the germination rate was 100% (unpublished data A. Cochrane ). Germinants from these trials are delivered to Botanic Garden and Parks Authority (BGPA) nursery for maturation into full plants.

The BGPA currently have two plants of Thomasia sp. Green Hill from two clones. The species has been difficult to propagate in this way, with success ranging from 0% to 60% (personal communication A. Shade ).

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

Staff of the Department's Moora District regularly monitor both subpopulations for changes in population size, level of threat and habitat condition. Individual plants at both subpopulations will be mapped to aid future surveys and monitoring, as plants are inconspicuous when not in flower.

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 Thomasia sp. Green Hill 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: $400 per year.

¹ Anne Cochrane, Manager, the Department's Threatened Flora Seed Centre
² Amanda Shade, Horticulturalist, Botanic Garden and Parks Authority

2. Maintain boundary fence

Adjacent farmland is periodically grazed by sheep and continued maintenance of the fence between the crop and the subpopulations is required to prevent any damage to Thomasia sp. Green Hill.

Action: Maintain boundary fence
Responsibility: The Department (Moora District) through the MDTFRT in consultation with the relevant Farm Managers
Cost: $600 in first year.

3. 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

4. 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. Special attention will be paid to the level of damage inflicted by kangaroo grazing, and action taken if deemed necessary. It is intended that individual plants will be mapped or marked to enable survey when the species is not in flower, and for collection of seed.

Action: Monitor population
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1000 per year.

5. Obtain biological and ecological information

Improved knowledge of the biology and ecology of Thomasia sp. Green Hill will provide the necessary 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, recruitment and resprouting from rootstock.
  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.
  • Action: Obtain biological and ecological information
  • Responsibility: The Department (Science Division, Moora District) through the MDTFRT with assistance from the BGPA
  • Cost: $20,000 per year in the second, third and fourth years

6. 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.

Staff of the Moora District also will work with local Community Support Officers to help increase awareness of the species. Information sheets on Thomasia sp. Green Hill will be distributed opportunistically to the local community.

Action: Promote awareness
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,900 in second year.

7. Collect seed and cutting material

Preservation of germplasm is essential to guard against extinction if wild populations are lost, and to protect the remaining genetic diversity. Such collections are also needed to propagate plants for translocations. A small amount of seed and cutting material have been collected from both subpopulations but further collections are required.

  • Action: Collect seed and cutting material
  • Responsibility: The Department (TFSC, Moora District) through the MDTFRT
  • Cost: $2,300 per year

8. Undertake and monitor translocation

Translocation is highly desirable for the conservation of this species, as the number of extant plants is low and its range is extremely limited. It is therefore susceptible to both a single catastrophic event as well as the ongoing threats of weed competition, grazing, fire and chemical drift.

A Translocation Proposal will be developed and suitable translocation sites sought. Plants will be propagated in readiness for translocation, and when appropriate, these will be planted in accordance with the approved Translocation Proposal. 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 translocations is essential and will be undertaken according to the timetable developed for the Translocation Proposal.

Action: Undertake and monitor translocation
Responsibility: The Department (Science Division, Moora District) and BGPA through the MDTFRT
Cost: $23,000 in first year and $7,500 per year in subsequent years

9. Undertake weed control

Subpopulations 1a and 1b are moderately weed infested. Adult Thomasia sp. Green Hill plants appear to cope well with weed competition, but the impact on recruitment is likely to be greater. Weed control will be undertaken through 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 weed control will be followed by a report on the method, timing and success of the treatment against weeds, and the effect on Thomasia sp. Green Hill and associated native plant species.

  • Action: Undertake weed control
  • Responsibility: The Department (Moora District, Science Division) through the MDTFRT in consultation with the relevant Farm Manager
  • Cost: $2,400 per year

10. Develop and implement a fire management strategy

The response of this species to fire is unknown, but it is likely that the species requires occasional fire for recruitment from soil-stored seed. Frequent fires, however, are likely to be detrimental to its long-term survival. Fire also promotes the introduction and proliferation of weed species. Following research into the species' fire response, a fire management strategy will be developed.

Action: Develop and implement a fire management strategy
Responsibility: The Department (Moora District) through the MDTFRT and relevant Farm Managers Cost: $1,700 in first year and $1,000 in subsequent years

11. Seek long-term protection of habitat

Staff from the Department's Moora District will continue to liaise with relevant 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 sought. This may include conservation covenants with a range of agencies, and/or the Land for Wildlife scheme.

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

12. Conduct further surveys

Further surveys by Departmental staff and community volunteers will be conducted on a systematic basis during the species' flowering period (October) in areas of suitable habitat. With the permission of the landowners, appropriate habitat on other private lands will be surveyed. Volunteers from the local community, Landcare groups, Wildflower Societies, and/or Naturalist Clubs will be invited to be involved in surveys supervised by Departmental staff.

Action: Conduct further surveys
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $1,700 per year

13. Stimulate germination of soil-stored seed

Burning, smokewater and soil disturbance may be effective in stimulating the germination of soil-stored seed. Where appropriate, these trials will be conducted near existing subpopulations in disturbed areas newly cleared of weeds.

Action: Stimulate germination of soil-stored seed
Responsibility: The Department (Moora District) through the MDTFRT
Cost: $4,400 in first year, and $1,000 in subsequent years

14. 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 a full Recovery Plan is required)