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 Endangered
Listing and Conservation Advices Commonwealth Conservation Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008adz) [Conservation Advice].
 
Commonwealth Listing Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008aee) [Listing Advice].
 
Recovery Plan Decision Recovery Plan not required, local actions are being undertaken to assist the species and most subpopulations are located within Crown reserves. Therefore the approved Conservation Advice for the species provides sufficient direction to implement priority actions and manage the threats posed by weed invasion and salinity (19/12/2008).
 
Adopted/Made Recovery Plans
Other EPBC Act Plans Fitzgerald Biosphere Recovery Plan: A Landscape Approach to Threatened Species and Ecological Communities Recovery and Biodiversity Conservation (Western Australia Department of Environment and Conservation (WA DEC), 2012) [Recovery Plan].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (69) (19/12/2008) (Commonwealth of Australia, 2008d) [Legislative Instrument].
 
State Government
    Documents and Websites
WA:Declared Rare & Poorly Known Flora in the Albany District. Western Australian wildlife management program no. 20 (Robinson, C.J. & D.J. Coates, 1995) [State Action Plan].
State Listing Status
WA: Listed as Endangered (Wildlife Conservation Act 1950 (Western Australia): September 2013 list)
Scientific name Boronia clavata [5538]
Family Rutaceae:Sapindales:Magnoliopsida:Magnoliophyta:Plantae
Species author Paul G.Wilson
Infraspecies author  
Reference Wilson, Paul G. (1971) Taxonomic notes on the family Rutaceae, principally of Western Australia. Nuytsia 1(2): 199 [tax. nov.]
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.

Illustrations Google Images
http://florabase.calm.wa.gov.au/browse/profile/4408

An upright, slender shrub, growing 0.5–1.5 m high; it was once recorded as high as 2.1 m. The leaves are 10–20 mm long on a short stem. Flowers are yellowish to greenish, and the flowering period is from August to October (Western Australian Herbarium n.d.).

The species is endemic to Western Australia and is known from five populations in the Bremer Bay area approximately 150 km east-north-east of Albany. The greatest distance between populations is approximately 18 km. All known populations occur within the South Coast Natural Resource Management Region. It is likely that current range has been reduced by land clearing of suitable habitat in the Bremer-Gairdner area (TSSC 2008aee).

The extent of occurrence is estimated to be approximately 76 km². A dataset taken from the Western Australian Department of Conservation and Land Management's (currently the Department of Environment and Conservation) Threatened Flora Database (which contains a single GPS coordinate for each population) was used to determine the area of occurrence (WA CALM 2006).

There is insufficient data to calculate the actual area of occupancy, as none of the five populations have their area of occupancy recorded. As the number of plants at each population is very small, the area of occupancy is estimated to be considerably less than 1 km² for each population. Therefore the area of occupancy is less than 5 km² (WA CALM 2006).

The predictions for this taxon's future area of occupancy based on the most recent survey data suggest that the populations should remain stable with a potential for seedling recruitment. All populations are in a healthy condition and not under any immediate threats from human disturbance during pre-2006 surveys (WA CALM 2006).

The species distribution is not considered to be fragmented as the known populations occur within a continuous area of vegetation that has not been cleared. Although populations are scattered with some distance between them, this is believed to be its natural distribution pattern (WA CALM 2006). However, known and similar vegetation occurs as isolated patches surrounded by cleared land (Overhieu 2004).

Extensive surveys were undertaken in the Bremer Bay area in 1993 during the preparation of the Declared Rare and Poorly known Flora in the Albany District (Robinson & Coates 1995) Wildlife Management program. A survey was undertaken over three days in 1999 of the Bremer, Gairdner and Devil Creek Rivers; however the survey did not cover all the alluvial flats on the Bremer River due to difficulty of access. It was noted that several more populations might potentially exist in areas of suitable habitat that were not accessible. In 2000 the banks of the Bremer River were accessed by boat and kayak, which resulted in two new populations (populations 3 and 4) being found (WA CALM 2006).

The following table presents survey dates for the Bremer Boronia populations (WA CALM 2006):

Population Number Survey date
1a 06/09/1993
18/11/1998
1b 1993
06/10/1998
18/11/1999
2 06/09/1993
06/10/1998
3 26/02/2000
4 26/02/2000
5a 17/11/1999
5b 17/11/1999

The total population size for the Bremer Boronia is estimated to be approximately 97 mature plants from five populations (actual plant numbers were counted during the monitoring of populations). All populations are healthy, except population 2 (WA CALM 2006). The number of known individuals may be an underestimate due to the limited accessibility of some areas of suitable habitat (TSSC 2008aee).

The following table presents the most recent known plant numbers (WA CALM 2006):

Population number Plant numbers Last available survey date
1a 1 6/10/1999
1b 32 18/11/1999
2 0 6/10/1999
3 10 26/2/2000
4 40 26/2/2000
5a 9 17/11/1999
5b 5 17/11/1999

The survey history for the Bremer Boronia is limited and does not allow for extrapolation on the species population trends. Nevertheless, all populations were found to be in a healthy condition based on the most recent survey data suggesting that the populations should remain stable with the potential for seedling recruitment (WA CALM 2006).

Given that there are only about 97 plants across five populations, all known populations would be considered important for the Bremer Boronia's recovery and long-term survival (WA CALM 2006).

Only one population occurs within conservation estate (Fitzgerald River National Park), however the majority of the remaining populations occur on a non-vested Crown Reserve adjacent to the National Park. This Crown Reserve may be included within the reserve system in the future (WA CALM 2006). One of the objectives of the Fitzgerald River National Park's Management Plan (Moore et al. 1992) is to protect and maintain viable populations of all existing species, especially rare species.

The Bremer Boronia grows in alluvial sand and loam and occurs in floodplains and river beds. The species' habitat appears to be quite specialised and confined to narrow alluvial flats on sections of the Bremer River between spongelite cliffs (Westerm Australian Herbarium n.d.).

Little is known about the reproductive biology of the Bremer Boronia. Flooding may stimulate germination (WA CALM 2006).

The flowering period for the Bremer Boronia is from August to October (Western Australian Herbarium n.d.). Little is known about the levels of flower and fruit production of this species. However, it is suspected that the species is likely to be influenced by flooding when scarification of seed may stimulate germination. The pollination mechanism has not been studied, although the species' floral structure suggests it employs an insect pollinating mechanism (WA CALM 2006).

Surveys should focus on similar soil and vegetation types and, as the species has a small growth habit, should be carried out during the flowering season (August-October). Flowers of the Bremer Boronia are not very prominent (yellowish to greenish in colour), but when the plant is in full flower it is reasonably distinctive therefore it should be readily located if present (WA CALM 2006).

The following table presents threats for the Bremer Boronia (WA CALM 2006):

Populations Past Present Future
1–5 Land Clearing Salinity and weed invasion Climate change, salinity and weed invasion

The susceptibility of the Bremer Boronia to salinity is unknown. Widespread shrub and overstorey deaths have been observed on the Gairdner River, which may be due to salinity. However, no specimens of this species have been located in this area. Salinity may potentially affect the Bremer River and Devil's Creek populations (WA CALM 2006).

Climate change and the associated processes such as sea level rise and increases in carbon dioxide levels are expected to affect biodiversity in Western Australia during the next few decades (WA CALM 2004). It is of particular threat to rare species that are often already occurring in small fragmented populations that have evolved specifically to their habitat. Should particular parameters of their habitat change, such as climatic conditions, the species may not be able to adapt and extinction may follow (WA CALM 2006).

Minister's reasons for recovery plan decision

Local actions are being undertaken to assist the species and most subpopulations are located within Crown reserves. Therefore the approved Conservation Advice for the species provides sufficient direction to implement priority actions and manage the threats posed by weed invasion and salinity. A recovery plan is not considered to be necessary at this time.

Other priority actions

The Declared Rare and Poorly Known Flora in the Albany District (Robinson & Coates 1995) and the Conservation Advice for Boronia clavata (TSSC 2008adz) outline recovery actions including:

  • Design and implement a monitoring program or, if appropriate, support and enhance existing programs.
  • Protect further areas of native vegetation which contain populations of the species or which could support populations in the future.
  • Develop and implement a management plan for the control of weeds in the region.
  • Undertake survey work in suitable habitat and potential habitat to locate any additional populations.

Documents that may assist in the management of the Bremer Boronia include the Declared Rare and Poorly Known Flora in the Albany District (Robinson & Coates 1995) and the Conservation Advice for Boronia Clavata (TSSC 2008adz).

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
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Commonwealth Listing Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008aee) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds Commonwealth Conservation Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008adz) [Conservation Advice].
Natural System Modifications:Dams and Water Management/Use:Salinity Commonwealth Conservation Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008adz) [Conservation Advice].
Commonwealth Listing Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008aee) [Listing Advice].
Species Stresses:Indirect Species Effects:Low numbers of individuals Commonwealth Listing Advice on Boronia clavata (Threatened Species Scientific Committee (TSSC), 2008aee) [Listing Advice].

Moore, S., M. Cavana, K. Gillen, C. Hart, S. Hopper, K. Orr & W. Schmidt (1992). Fitzgerald River National Park Management Plan 1991-2001. Perth: Department of Conservation and Land Management.

Overhieu, T. (2004). Bremer-Gairdner Catchment appraisal 2003. Resource management technical report 273. Western Australia: Department of Agriculture.

Robinson, C.J. & D.J. Coates (1995). Declared Rare & Poorly Known Flora in the Albany District. Western Australian wildlife management program no. 20. [Online]. Como, Western Australia: Australian Nature Conservation Agency, Department of Conservation and Land Management. Available from: http://www.dpaw.wa.gov.au/plants-and-animals/threatened-species-and-communities/threatened-plants.

Threatened Species Scientific Committee (TSSC) (2008adz). Commonwealth Conservation Advice on Boronia clavata. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/5538-conservation-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2008aee). Commonwealth Listing Advice on Boronia clavata. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/5538-listing-advice.pdf.

Western Australia Department of Conservation and Land Management (WA CALM) (2006). Records held in CALM's Declared Flora Database and rare flora files. Perth, Western Australia: WA CALM.

Western Australian Department of Conservation and Land Management (WA CALM) (2004). Towards a Biodiversity Conservation Strategy for Western Australia Discussion Paper. Western Australia: Department of Conservation and Land Management.

Western Australian Herbarium (n.d.). FloraBase - The Western Australian Flora. [Online]. Western Australia, Department of Conservation and Land Management. Available from: http://florabase.calm.wa.gov.au/.

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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). Boronia clavata in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 21 Aug 2014 12:42:27 +1000.