Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Vulnerable as Gastrolobium modestum
Listing and Conservation Advices Commonwealth Conservation Advice for Gastrolobium modestum (Broad-leaved Gastrolobium) (Threatened Species Scientific Committee (TSSC), 2014dh) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan not required, the approved conservation advice for the species provides sufficient direction to implement priority actions and mitigate against key threats (29/04/2014).
 
Adopted/Made Recovery Plans
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument] as Brachysema modestum.
 
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (11/04/2007) (Commonwealth of Australia, 2007f) [Legislative Instrument] as Gastrolobium modestum.
 
State Government
    Documents and Websites
WA:Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
State Listing Status
WA: Listed as Vulnerable (Wildlife Conservation Act 1950 (Western Australia): September 2013 list) as Gastrolobium modestum
Scientific name Gastrolobium modestum [78361]
Family Fabaceae:Fabales:Magnoliopsida:Magnoliophyta:Plantae
Species author (Crisp) G.Chandler & Crisp
Infraspecies author  
Reference Australian Systematic Botany 15(5): 694, fig. 124 (2002)
Other names Brachysema modestum [64555]
Brachysema modestum Crisp ms. [67396]
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Other illustrations Google Images

The current conservation status of the Gastrolobium modestum under Australian and State/Territory Government legislation is as follows:

National: Listed as Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999.

Western Australia: Listed under the Wildlife Conservation Act 1950 as Declared Rare Flora.

Scientific name: Gastrolobium modestum

Common name: Broad-leaved Gastrolobium

Prior to Chandler and colleagues (2002) taxonomic revision of the genus Gastrolobium, this species was known as Brachysema modestum or the Broad-leaved Brachysema.

The Broad-leaved Gastrolobium is a shrub that grows to 0.5 m high and is 1 to 3 m broad. The stems are prostrate to ascending, with the former creating runners, in this case, through litter (i.e. stoloniferous), and often rooting at nodes. Flowers are cream to pale green, infused with pale pink (Atkins 1998; Chandler et al. 2002; Crisp 1995b; Williams et al. 2001).

Broad-leaved Gastrolobium occurs in southwestern Western Australia, near Busselton, south of Perth, on the edge of the Whicher Range (Chandler et al. 2002).

This species is endemic to Western Australia, where it is known from two subpopulations near the Whicher Range in the Busselton area, approximately 200km south of Perth (Chandler et al. 2002). As there are only two subpopulations, the extent of occurrence is estimated to be the distance between these, which is approximately 35km².

There is no data available on the species to determine if there was a past decline in extent of occurrence, however there is evidence that 90% of its associated habitat (Busselton Ironstone community) has been destroyed (English 1999c). It is possible that the extent of occurrence may decline in the future due to threatening processes.

During the most recent monitoring of the two subpopulations by Western Australian Department of Environment and Conservation (DEC) District staff, the area of occupancy for this species was estimated to be approximately 0.24 km². No data to indicate a past decline in area of occupancy of the species is available, however, much of the associated habitat (Busselton Ironstone Community) has been destroyed (English 1999c).

Broad-leaved Gastrolobium is considered to be severely fragmented, as the two subpopulations known are separated by approximately 35km of unsuitable habitat.

Broad-leaved Gastrolobium was first collected in the 1970s but was incorrectly identified as Gastrolobium minus. It was subsequently recognised as a separate species during the floristic surveys of the Swan Coastal Plain in the early 1990s (Gibson et al. 1994) and was at that time known only from a single location. Extensive surveys were conducted throughout the Treeton area from 1992 to 1994, which failed to locate additional populations.

The ironstone soils that the species is associated with are extremely restricted in distribution on the Swan Coastal plain and have been largely cleared. It was thought unlikely there were more populations to be found, as all known suitable habitat had been surveyed. However a second subpopulation was discovered in 1995 along an ironstone creek system in an island remnant within part of a pine plantation. This subpopulation was in the Whicher Range rather than on the Swan Coastal Plain. Since then both subpopulations have been monitored several times and no new subpopulations have been found.

Subpopulation 1 was surveyed in October 2006 in anticipation of a prescribed burn to be undertaken. A number of groups (as individual plants are hard to identify) were tagged both within the proposed burn area and outside the area for regeneration studies.

It is highly likely the current known distribution reflects the actual distribution of Broad-leaved Gastrolobium.

The total population size of Broad-leaved Gastrolobium is thought to be over 1 100 mature plants. The species clonal growth habit results in a dense cover of the forest floor, making it difficult to count the number of individual plants.

Broad-leaved Gastrolobium is known from only two subpopulations occurring in State Forest, near the Whicher Range. Subpopulations are defined as a geographically distinct groups between which there is little or no genetic exchange.

The total number of plants at subpopulation 1 is unknown, but estimated to be in the hundreds. Its clonal growth habit results in a dense cover of the forest floor, covering an area of approximately five hectares.

In 1996 there were estimated to be thousands of plants in good condition covering approximately 19 hectares at subpopulation 2.

The little survey data available indicates the populations are fairly stable and are likely to remain that way; however, difficulties in counting individuals means number of plants recorded are crude estimates only. A prescribed burn planned for subpopulation 1 may result in a short-term reduction in the number of plants in the future.


Sub-population Survey History Number of Plants Recorded Condition
1 03/05/1993
02/09/1994
22/1/1996
15/11/1996
06/06/2001
Not recorded
Not recorded
100s
100s
100+

Undisturbed

Healthy
Healthy
2 29/03/1995
27/12/1996
1 000s
1 000s
Disturbed
Healthy
(DEC 2007a)

Broad-leaved Gastrolobium does not appear to undergo extreme fluctuations in population numbers.

None of the subpopulations occur within the formal conservation reserve system.

This species habitat consists of laterite (or ironstone) gullies, with sand, loam, and clay soils, and moist and seasonal wetland conditions. It occurs in Jarrah Low Forest (Atkins 1998).

This species grows on edges of an ironstone flat and drainage line, where the soil is shallow and varies from red clay-loam to grey sand (Chandler et al. 2002; Crisp 1995b), in what appears to be a transitional vegetation community between ironstone outcrops and adjacent sand over clay habitats (Brown et al. 1998). Thus it occurs in an ecotone between seasonally swampy heath dominated by Dasypogon and Xanthorrhoea (on the ironstone flat) and open-forest dominated by Eucalyptus marginata (Jarrah) and E. calophylla (Marri) (Chandler et al. 2002; Crisp 1995b). The specialised nature of its habitat may explain the extreme localisation of this species. However, within the ecotone it is quite common, forming conspicuous hummocks (Crisp 1995b).

Subpopulation 1 is associated with the Endangered (EPBC Act) Shrublands on Southern Swan Coastal Plain Ironstones (Busselton area) Threatened Ecological Community (TEC). It occurs with two other threatened taxa that are both listed under the EPBC Act: Dryandra nivea subsp. uliginosa (Endangered) and Dryandra squarrosa subsp. argillacea (Whicher Range Dryandra) (Vulnerable).

Broad-leaved Gastrolobium flowers from September to November (Atkins 1998; Chandler et al. 2002; Crisp 1995b; Williams et al. 2001).

The species may be fire resistant as the area has a history of regular burning. It is possible that the species may benefit from autumn burns as it may cause germination of seed stored within the soil (Williams et al. 2001).

Broad-leaved Gastrolobium has large glossy green leaves and its pink-white flowers are hidden among the foliage at ground level, which makes it often hard to detect when in flower. Broad-leaved Gastrolobium is difficult to confuse with any other species of Gastrolobium except for Gastrolobium minus, which has a similar general aspect and recurved margins at the apex of the standard on the flower. However, the inflorescence-bearing stems in G. minus are leafy and never produce runners along the ground (i.e. stoloniferous); the flowers never form a panicle, and are smaller with typical red petals and yellow markings on the standard (Chandler et al. 2002).

Surveys should focus on remnant vegetation in similar soil and vegetation types during late spring.

The following threats have been identified:

Clearing for agriculture has been extensive on the heavy soils on the eastern side of the Swan Coastal Plain, with some 97% of all vegetation in the area cleared historically (Keighery & Trudgen 1992). Clearing has massively impacted the Swan Coastal Plain Ironstone community type, with which Broad-leaved Gastrolobium is associated, and this community has suffered almost total destruction. In accordance with the Memorandum of Understanding for the protection of remnant vegetation on private land in the agricultural region of Western Australia (Commissioner for Soil and Land Conservation et al. 1997), new proposals to clear occurrences of this community would be subject to Environment Protection Agency assessment.

Disease caused by the plant pathogen Phytophthora cinnamomi (Pc) is known to exist in the habitat of Broad-leaved Gastrolobium, but its susceptibility to the disease is unknown. The species is probably resistant as there is no evidence of an effect on the subpopulations (Williams et al. 2001). However, even if Broad-leaved Gastrolobium is resistant to the disease in situ, Phytophthora may have indirect impacts on the species through altering the composition and structure of the community. Such changes can result in altered levels of shade, soil moisture retention and competition, and other factors (DEC 2007a). Discoloration and leaf curl, similar to a rust infection, is evident on many plants (Williams et al. 2001).

Fire may affect the viability of the population. The species may be fire resistant as the area has a history of regular burning. It is possible that the species may benefit from autumn burns, as they may cause germination of seed stored within the soil and it is possible the species regenerates from rootstock after a fire (Williams et al. 2001). Too frequent fire could, however, deplete soil-stored seed and reserves held in rootstocks of individual plants, and also exacerbate the impact of disease on the habitat (DEC 2007a).

Changes to hydrology may in future become a threat to the population. Extensive clearing for agriculture in the area is likely to have caused an increase in surface runoff and recharge of the groundwater. Altered periods of ponding may also affect the timing of habitat growth and affect species composition within the habitat by favoring different species (DEC 2007a).

The subpopulation within the Quilergup State Forest Block adjoins a pine plantation and is at risk of disturbance from pine harvesting operations (Williams et al. 2001).

Other activities such as Roaging (similar to orienteering) and Motor Sport are increasing. One event last year was directly in the vicinity, and measures such as track realignment and establishment of no-go zones for spectators and vehicles was put in place (DEC 2007a).

The following actions have been identified for the management and conservation of Broad-leaved Gastrolobium but have yet to be completed (Williams et al. 2001):

  • Collection and storage of propagation material.
  • Further survey work.
  • Monitoring.
  • Minimising access to avoid plant damage from human disturbance.
  • Placement of Declared Rare Flora markers.
  • Cryostorage of genetic variants that are identified.
  • Localised publicity campaign.
  • Excision of portion of State Forest to Nature Reserve.
  • Investigation of translocation sites.
  • Scientific research:
        •Definition of genetic variation within subpopulations so that any variant can be put into cryostorage.
        •Development of rapid and reliable propagation method of vegetative and seed stock. At present six plants have been successfully propagated by the Botanic Gardens and Parks Authority.
        •Ascertain the level of stored seed in the soil. No seed has yet become available for collection.
        •Development of rapid, reliable germination techniques to provide revegetation stock or seed.

Declared Rare Flora Markers have been installed by DEC staff on tracks adjacent to the subpopulations to identify high conservation areas and therefore prevent accidental damage or disturbance of the area.

There have been no major studies undertaken specifically on this species.

Key management documentation is as follows:

 

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Agriculture and Aquaculture:Wood and Pulp Plantations:Habitat destruction due to forestry activities Gastrolobium modestumin Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006lt) [Internet].
Human Intrusions and Disturbance:Recreational Activities:Disturbance, especially from human recreational activities and development Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Vegetation and habitat loss caused by dieback Phytophthora cinnamomi Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009w) [Threat Abatement Plan].
Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].
Natural System Modifications:Fire and Fire Suppression:Inappropriate prescribed regimes and/or vegetation management to control fire regimes Species threats data recorded on the SPRAT database between 1999-2002 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012i) [Database].
Species Stresses:Indirect Species Effects:Low numbers of individuals Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2 (Williams, K., A. Horan, S. Wood & A. Webb, 2001) [State Species Management Plan].

Atkins, K.J. (1998). Conservation Statements for threatened flora within the regional forest agreement region for Western Australia. Page(s) 1-95. Western Australia: Department of Conservation and Land Management.

Brown, A., C. Thomson-Dans & N. Marchant, eds. (1998). Western Australia's Threatened Flora. Como, Western Australia: Department of Conservation and Land Management.

Chandler, G.T., M.D. Crisp, L.W. Cayzer & R.J. Bayer (2002). Monograph of Gastrolobium (Fabaceae: Mirbelieae). Australian Systematic Botany. 15(5):619-739. Collingwood, Victoria: CSIRO Publishing.

Commissioner for Soil and Land Conservation, Chairman EPA, CEO Department of Environmental Protection, CEO Agriculture WA, Executive Director CALM, CEO Water and Rivers Commission (1997). Memorandum of Understanding between the authors for the protection of the remnant vegetation on private land in the agricultural region of Western Australia. Perth.

Crisp, M.D. (1995b). Revision of Brachysema (Fabaceae: Mirbelieae). Australian Systematic Botany. 8(3):307-353.

English, V. (1999c). Shrubland Association on Southern Swan Coastal Plain Ironstone (Busselton Area) (Southern Ironstone Association) Interim recovery Plan 1999 - 2002. Shrublands on southern Swan Coastal Plain ironstones in Species Profile and Threats (SPRAT) database. [Online]. Available from: http://www.environment.gov.au/cgi-bin/sprat/public/publicshowcommunity.pl?id=23.

Gibson, N., B.J. Keighery, G.J. Keighery, A.H. Burbidge & M.N. Lyons (1994). A floristic survey of the Southern Swan Coastal Plain. Unpublished report for the Australian Heritage Commission. Prepared by the Department of Conservation and Land Management and the Conservation Council of Western Australia (Inc.).

Keighery. B., & Trudgen, M. (1992). Remnant Vegetation on the Alluvial Soils of the Eastern Side of the Swan Coastal Plain. Unpublished report for Department of Conservation and Land Management, Australian Heritage Commission and Heritage Council of WA.

Williams, K., A. Horan, S. Wood & A. Webb (2001). Declared Rare and Poorly Known Flora in the Central Forest Region. Part 2. [Online]. Western Australian Wildlife Management Program No. 33. Department of Conservation and Land Management. Available from: http://www.dpaw.wa.gov.au/plants-and-animals/threatened-species-and-communities/threatened-plants.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Gastrolobium modestum in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 21 Aug 2014 19:29:50 +1000.