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
Listing and Conservation Advices Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].
 
Commonwealth Conservation Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cx) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan not required, the Threatened Species Scientific Committee recommended that there should not be a recovery plan for this species as the conservation advice provides sufficient direction to implement priority actions and mitigate against key threats (07/12/2009).
 
Adopted/Made Recovery Plans
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 (85) (07/12/2009) (Commonwealth of Australia, 2009d) [Legislative Instrument].
 
State Listing Status
SA: Listed as Endangered (National Parks and Wildlife Act 1972 (South Australia): June 2011 list)
Scientific name Acacia praemorsa [55363]
Family Fabaceae:Fabales:Magnoliopsida:Magnoliophyta:Plantae
Species author P.J.Lang & B.R.Maslin
Infraspecies author  
Reference J. Adelaide Bot. Gard. 13 (1990) 119.
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

Scientific name: Acacia praemorsa

Common name: Senna Wattle

Other name: Cassia Wattle

The species is conventionally accepted as Acacia praemorsa (Senna Wattle) (Lang et al. 1990).

The Senna Wattle is an erect, suckering, hairless shrub, 1–3 m high with smooth, green, angled branchlets and long, linear, soft phyllodes (leaf-like structures) (Lang et al. 1990). The phyllodes are linear, 2–9 cm long and 1.5–2.5 mm wide (Whibley & Symon 1992). The bright-yellow, globular flower heads occur in groups of one or two (Lang et al. 1990). The legumes (fruit) are linear, dark green, flat or twisted and up to 13 cm long (Whibley & Symon 1992).

The Senna Wattle is endemic to South Australia. It is confined to the Eyre Peninsula where it occurs in localised populations in the ranges north-east of Cleve (Lang et al. 1990).

In 2005, the extent of occurrence of Senna Wattle was estimated to be 31 km² (SA DEH 2005a; State Herbarium of South Australia 2005). This estimate suggests that the geographic distribution is very restricted (TSSC 2009cw).

The Senna Wattle is known from seven populations. There are population data available for four populations, with numbers in each population ranging between 500–1000 mature individuals (Lang et al. 1990; SA DEH 2005a). There are no data on the number of individuals in the other three recorded populations (TSSC 2009cw).

The Senna Wattle was first collected in 1986 and surveyed only several times since. The most recent survey was in 1992 (SA DEH 2005a). It is possible that there was a historical decline in numbers, prior to its discovery in 1986, as a result of vegetation clearance. Vegetation clearance is known to have occurred within the species' distribution; however, it is difficult to confirm a decline in the population size of the Senna Wattle as the species now appears to be restricted to rocky ranges that have remained vegetated. As the majority of populations have been protected since 1986, it seems unlikely that the population has declined since this time. However, data collections have not been made over a sufficient time period to assess whether the species has declined or is in decline (TSSC 2009cx).

The Senna Wattle occurs in mallee woodlands, open scrubs and open heath scrubs (State Herbarium of South Australia database 2005). The species has been found on the lower slopes of small gullies in low, rocky ranges (Lang et al. 1990), on exposed north-facing slopes in thick, low scrub (State Herbarium of South Australia 2005) and in shady, sheltered sites in open mallee woodlands at the base of steep gullies (Lang et al. 1990).

Mallee woodlands where the Senna Wattle have been recorded comprise White Mallee (Eucalyptus dumosa) and Red Mallee (E. socialis) heaths with Broom Honey-myrtle (Melaleuca uncinata), White Mallee, Cong Mallee (E. conglobata), Peppermint Box (E. odorata), Narrow-leaved Red Mallee (E. leptophylla) open scrub over Wallowa (Acacia calamifolia); Peppermint Box open scrub over Dodonaea hexandra and Rough Halgania (Halgania cyanea); and Peppermint Box low woodland to open scrub with Broom Honey-myrtle, Speargrass (Gonocarpus elatus, G. mezianus, Austrostipa spp.) and Wallaby-grass (Austrodanthonia spp.). The species has also been recorded from Drooping Sheoak (Allocasuarina verticillata) and Broom Honey-myrtle broombush heath and low scrub with Pultenaea teretifolia, Flame Heath (Astroloma conostephioides), Spoon-leaf Spyridium (Spyridium spathulatum), and Broom Honey-myrtle (State Herbarium of South Australia 2005).

Key threats to the Senna Wattle are grazing and trampling by domestic stock, and inappropriate fire regimes, including unplanned catastrophic fires. A historical threat includes habitat loss and fragmentation through vegetation clearance (TSSC 2009cw).

Grazing and trampling by domestic stock
The current key threat to the Senna Wattle is grazing and trampling by domestic stock. This threat is only likely to impact the two populations that are known to occur on agricultural land. Of the remaining populations, one occurs in a conservation reserve and four are protected from grazing under Heritage Agreements on private property (TSSC 2009cw).

Inappropriate fire regimes
Inappropriate fire regimes are a potential threat to the Senna Wattle. The species response to fire is unknown; however, inappropriate intervals between fires may affect recruitment in all populations. Additionally, the seven populations of Senna Wattle are known from only one location. One catastrophic fire within this location may potentially eliminate the species (TSSC 2009cw).

Vegetation clearance
A significant historical threat to the Senna Wattle is likely to have been vegetation clearance in the pastoral landscape in which it occurs, leading to habitat loss and fragmentation. Vegetation clearance is known to have occurred within the species' range, particularly in the Hundred of Mann, Hundred of Mangalo and Mount Desperate environmental association, where 38.3%, 14.2% and 38.8% of the native vegetation remains respectively (State Herbarium of South Australia 2005; SA DEH 2002).

Minister's Reasons for Recovery Plan Decision
The Threatened Species Scientific Committee recommended that there should not be a recovery plan for this species as the conservation advice provides sufficient direction to implement priority actions and mitigate against key threats.

The Commonwealth Conservation Advice on Acacia praemorsa (Senna Wattle) (TSSC 2009cx) outlines the following research priorities:

  • Design and implement a monitoring program.
  • More precisely assess population size, distribution, reproductive biology and ecological requirements.
  • Undertake seed germination and/or vegetative propagation trials to determine the requirements for successful establishment.
  • Undertake research on the species' response to fire.

In addition, the Commonwealth Conservation Advice on Acacia praemorsa(Senna Wattle) (TSSC 2009cx) outlines the following priority actions:

  • Monitor known populations to identify key threats.
  • Control access routes to suitably constrain public access to known sites on public land.
  • Undertake survey work in suitable habitat and potential habitat to locate any additional populations.
  • Continue to protect populations of the listed species through the development of conservation agreements and/or covenants.
  • Manage known sites on private property to ensure domestic livestock grazing regimes allow flowering, seed set and seedling survival.
  • Prevent grazing pressure at known sites on leased crown land through exclusion fencing or other barriers.
  • Implement an appropriate fire management regime for local populations.
  • Develop and implement a management plan for the Yeldulknie Conservation Park.

The Commonwealth Conservation Advice on Acacia praemorsa (Senna Wattle) (TSSC 2009cx) provides a brief biological overview and management recommendations.

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:Agriculture and Aquaculture:Land clearing, habitat fragmentation and/or habitat degradation Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].
Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].
Agriculture and Aquaculture:Livestock Farming and Grazing:Habitat alteration (vegetation, soil, hydrology) due to trampling and grazing by livestock Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle) (Threatened Species Scientific Committee (TSSC), 2009cw) [Listing Advice].

Lang, P.J., B.R. Maslin & R.S. Cowan (1990). Plant Portraits. Journal of the Adelaide Botanic Gardens. 13:118-123.

South Australia Department for Environment and Heritage (SA DEH) (2002). Remnant vegetation data within Environmental associations for South Australia. Adelaide. South Australia: SA DEH.

South Australia Department for Environment and Heritage (SA DEH) (2005a). SA DEH databases comprising of the Opportune Database, Plant Population Database, Reserves Database, Roadside Vegetation Database and Survey Database. Adelaide, South Australia: Department of Environment and Heritage.

State Herbarium of South Australia (2005). ADHERB Database. South Australia: State Herbarium of South Australia.

Threatened Species Scientific Committee (TSSC) (2009cw). Commonwealth Listing Advice on Acacia praemorsa (Senna Wattle). [Online]. Department of the Environment, Water, Heritage and the Arts. Canberra, ACT: Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/55363-listing-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2009cx). Commonwealth Conservation Advice on Acacia praemorsa (Senna Wattle). [Online]. Department of the Environment, Water, Heritage and the Arts. Canberra, ACT: Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/55363-conservation-advice.pdf.

Whibley, D.J.E. & D.E. Symon (1992). Acacias of South Australia. Adelaide, South Australia: Flora and Fauna of South Australia Handbook Committee.

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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). Acacia praemorsa in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 20 Aug 2014 17:48:51 +1000.