Grevillea obtusiflora subsp. obtusiflora and subsp. fecunda Recovery Plan

NSW National Parks and Wildlife Service, September 2001
ISBN 0 731 36281 0

Appendix 4. - Information Sheet and EIA Guidelines

Threatened Species Information - Grevillea obtusiflora including both subspecies obtusiflora and fecunda

Conservation Status

G. obtusiflora is listed as an endangered species on Schedule 1 of the Threatened Species Conservation Act 1995, and the Commonwealth Endangered Species Protection Act 1992.

Briggs and Leigh (1996) assign a conservation status of Grevillea obtusiflora as 2E. Makinson (1997) recommends a classification of 2Vi for Grevillea obtusiflora subsp. fecunda pending a full survey.

Description

G. obtusiflora subsp. obtusiflora

G. obtusiflora subsp. obtusiflora is a low, multi-stemmed shrub to half a metre tall, the leaves are narrow flowers are pink to pinkish red. It is not known to set fruit or seed.

Grevillea obtusiflora subsp. obtusiflora.
Grevillea obtusiflora subsp. obtusiflora.

G. obtusiflora subsp. fecunda

G. obtusiflora subsp. fecunda is a low, dense shrub to one metre tall.

Leaves narrow. Flowers profusely with pale to deep pink to crimson flowers.

Grevillea obtusiflora subsp. fecunda.
Grevillea obtusiflora subsp. fecunda.

Distribution

G. obtusiflora subsp. obtusiflora

G. obtusiflora subsp. obtusiflora is known to occur near Rylstone in the in the central tablelands bioregion.

G. obtusiflora subsp. fecunda

G. obtusiflora subsp. fecunda is known to occur in the Capertee Valley, west of Lithgow, and in the Gardens of Stone National Park. Both sites are in the central tablelands botanical division.

Occurrences in conservation reserves

G. obtusiflora subsp. obtusiflora does not occur in conservation reserves.

One sub-population of G. obtusiflora subsp. fecunda occurs within the Gardens of Stone National Park.

Habitat

G. obtusiflora subsp. obtusiflora

G. obtusiflora subsp. obtusiflora occurs in the understorey of low open eucalypt forest at an altitude of 730 metres above sea level.

Species growing in association with G. obtusiflora subsp. obtusiflora include Eucalyptus crebra; E. dealbata; E. tenella, Callistemon linearis, Acacia buxifolia, Acacia elongata, Leucopogon sp., Caustis flexuosa, Dianella sp. and Patersonia sp.

G. obtusiflora subsp. fecunda

G. obtusiflora subsp. fecunda occurs on orange sandy loam soils with sandstone boulders in low open scrub beneath open dry sclerophyll forest, at an altitude of 570 metres.

Species growing in association with G. obtusiflora subsp. fecunda include Eucalyptus tenella, E. fibrosa, E. macrorhyncha, E. punctata, Callitris endlicheri, Acacia buxifolia, Leptospermum continentale, monotoca elliptica., Persoonia linearis, Indigofera sp., Pomax umbellata.

Ecology

G. obtusiflora subsp. obtusiflora

G. obtusiflora subsp. obtusiflora flowers sparsely in winter and spring with flowering peaking in October. Fruits, seeds and seedlings have not been recorded for this taxon, indicating that G. obtusiflora subsp. obtusiflora is apparently wholly dependent on root suckering for reproduction (Makinson, 1997).

G. obtusiflora subsp. obtusiflora's floral morphology indicates it is predominantly pollinated by birds, with bees being potential secondary pollinators.

Sub-population structure and isolation may affect pollination within and between sub-populations, hence fruit set (Eriksson and Bremer, 1993). Other biological causes of failure to produce seed may include inbreeding depression, self-incompatibility, pollen unviability, flower stigma non-receptivity or shrunken pollen grains.

Sub-populations of G. obtusiflora subsp. obtusiflora are scattered. The high degree of clonality of this species makes it difficult to identify and count individual genets. The sub-population sizes vary from a few isolated plants to several hundred plants/ramets covering up to 20 square metres.

The genus Grevillea is adapted to survive fire through several strategies. G. obtusiflora subsp. obtusiflora's root suckering habit would enable it to cope with a fire event. However, the effects of fire on the viability of the species. is unknown

G. obtusiflora subsp. fecunda

G. obtusiflora subsp. fecunda flowers abundantly in spring. and sets copious amounts of fruits (Makinson, 1997). Due to the particular flower morphology, G. obtusiflora subsp. fecunda is predominantly pollinated by birds, with bees being the potential secondary pollinators.

Seed is most likely dispersed directly below the plant and is distributed by wind, water and ants. Seedlings have been recorded soon after dehiscence.

Sub-populations of G. obtusiflora subsp. fecunda appear to be located in 'clusters' of suitable habitat. No information on growth rate and longevity is available.

G. obtusiflora subsp. fecunda appears respond favourably to mechanical soil disturbance and is known to quickly recolonise roadside scrapes.

Threats

Threats to both subsp. obtusiflora and fecunda may include: inappropriate fire regimes, loss of effective pollinator and roadside management activities.

Management

Management actions for both sub-species of G. obtusiflora include; liaison with landholders/ managers including State Forests of NSW and Rylstone Council to ensure the conservation of the plant populations, continued biological and ecological investigations and monitoring of the known populations, surveying of suitable habitat for further populations, and a community awareness strategy.

Recovery Plan

A recovery plan for Grevillea obtusiflora incorporating both subspecies obtusiflora and fecunda was approved in September 2001.

For Further Information contact

Threatened Species Unit Central Directorate NSW NPWS PO Box 1967, Hurstville NSW
2220 Phone 02 9585 6678
www.npws.nsw.gov.au

References

Makinson, R.O. (1997) Grevillea obtusiflora subsp. fecunda (Proteaceae : Grevilleoideae), a new subspecies from New South Wales. Telopea 7(2): 143-148

Makinson, R.O. (in press) Grevillea In Flora of Australia.

Important Disclaimer

The NSW National Parks and Wildlife Service and the editor expressly disclaim all liability and responsibility to any person, whether a purchaser or reader of this document or not, in respect of anything done or omitted to be done by any person in reliance upon the contents of this document although every effort has been made to ensure that the information presented in this document is accurate and up to date.

Environmental Impact Assessment Guidelines - Grevillea obtusiflora

The following information is provided to assist authors of Species Impact Statements, development and activity proponents, and determining and consent authorities, who are required to prepare or review assessments of likely impacts on threatened species pursuant to the provisions of the Environmental Planning and Assessment Act 1979. These guidelines should be read in conjunction with the NPWS Information Circular No. 2: Threatened Species Assessment under the EP&A Act: The '8 Part Test' of Significance (November 1996).

Survey

Surveys for both G. obtusiflora subsp. obtusiflora and subsp. fecunda can be conducted at any time of the year, however they are easier to locate while flowering from September to December.

Surveys should be conducted within suitable habitat within the range of this species, which include the Lithgow and Rylstone local government areas.

Life cycle of the species

The biology of Grevillea obtusiflora is described in the draft recovery plan and summarised in the attached profile. The lifecycle of G. obtusiflora subsp. obtusiflora and subsp. fecunda is likely to be disrupted should any of the following occur:

  • Habitat Modification could impact on the lifecycle of both G. obtusiflora subsp. obtusiflora and subsp. fecunda through direct and indirect impacts on individual plants or to the soil seed bank. Both subspecies have populations on roadside verges that are potentially under threat by road widening, slashing and weed spraying of broad areas with herbicide and phosphate sprays.
  • Inappropriate fire regimes may pose a threat to the lifecycle of both G. obtusiflora subsp. obtusiflora and subsp. fecunda, however, Grevilleas are adapted to persist after individual fire events. Prescribed burns for fuel reduction are carried out by the State Forests of NSW and Rylstone Council through the local Bush Fire Risk Management Committee. In the known habitats of G. obtusiflora subsp. obtusiflora and subsp. fecunda evidence indicates that regular fire events are uncommon.

Threatening processes

There are no key threatening processes listed under the Threatened Species Conservation Act 1995 that are relevant to these taxa.

Viable local population of the species

G. obtusiflora subsp. obtusiflora

The population is estimated at several hundred adult ramets in 10 sub-populations in the Clandulla State Forest, and scattered individuals outside State Forest boundaries.

Due to the lack of regular new genetic input from seed and the exclusive clonality of this species, this may be indicative that the genetic diversity of the population is low. It is unknown if this population is viable.

G. obtusiflora subsp. fecunda

The three sub-populations are estimated to have 50, 350, and 500 individuals. The extent of genetic transfer between the sub-populations is unknown.

Due to G. obtusiflora subsp. fecunda's ability to sexually reproduce and to colonise disturbed areas, it is probable that the populations of this species are viable.

A significant area of habitat

Due to the limited area occupied by this taxon, and the sensitivity of its habitat, all habitat and subpopulations of G. obtusiflora are significant.

Isolation/fragmentation

Both taxa are isolated. Further fragmentation of sub-populations may compromise their viability.

Regional distribution of the habitat

Although similar habitat is present in the area, despite survey no further sub-populations have been located. The parameters defining the preferred habitat for these species are yet to be identified.

Limit of known distribution

G. obtusiflora subsp. obtusiflora

G. obtusiflora subsp. obtusiflora occurs in Clandulla State Forest, and on adjacent land. near Rylstone in the Central Tablelands of NSW.

G. obtusiflora subsp. fecunda

Grevillea obtusiflora subsp. fecunda occurs along several roads in the Capertee Valley, west of Lithgow, and in the Gardens of Stone National Park.

Adequacy of representation in conservation reserves

G. obtusiflora subsp. obtusiflora

This taxon is not adequately represented in conservation reserves.

G. obtusiflora subsp. fecunda

A sub-population occurs in the Gardens of Stone National Park. This taxon is not adequately reserved

Critical habitat

Critical habitat has not been declared for G. obtusiflora.

For further information contact:

Threatened Species Unit, Central Directorate, NSW NPWS, PO Box 1967,
Hurstville NSW 2220. Phone: 9585 6678.
www. npws.nsw.gov.au

Important Disclaimer
The NSW National Parks and Wildlife Service and the editor expressly disclaim all liability and responsibility to any person, whether a purchaser or reader of this document or not, in respect of anything done or omitted to be done by any person in reliance upon the contents of this document although every effort has been made to ensure that the information presented in this document is accurate and up to date.