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
Recovery Plan Decision Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
 
Adopted/Made Recovery Plans National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].
 
Other EPBC Act Plans Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi (Department of the Environment, 2014a) [Threat Abatement Plan].
 
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].
 
State Government
    Documents and Websites
TAS:Xanthorrhoea bracteata (Shiny Grasstree): Species Management Profile for Tasmania's Threatened Species Link (Threatened Species Section (TSS), 2014fp) [State Action Plan].
TAS:Threatened Flora of Tasmania - Xanthorrhoea bracteata (Threatened Species Unit (TSU), 2003) [Information Sheet].
State Listing Status
TAS: Listed as Vulnerable (Threatened Species Protection Act 1995 (Tasmania): September 2012)
Scientific name Xanthorrhoea bracteata [7950]
Family Xanthorrhoeaceae:Liliales:Liliopsida:Magnoliophyta:Plantae
Species author R.Br.
Infraspecies author  
Reference Prodromus Florae Novae Hollandiae (27 Mar. 1810) 288.
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: Xanthorrhoea bracteata

Common name: Shiny Grasstree

The Shiny Grasstree was previously combined with Xanthorrhoea minor (Lee 1966, cited in Bedford 1986), however, the Shiny Grasstree was elevated to the species level due to distinct morphology and geography (Bedford 1986). X. minor does not otherwise occur in Tasmania (Bedford 1986).

The Shiny Grasstree is a trunkless perennial grass-tree, 30–50 cm tall, with below ground branches usually with several erect tufts of leaves (Barker & Johnson 1998; Bedford 1986; Curtis & Morris 1994). The leaves are 40–110 cm long and 1.5–3 mm wide. The flower head is usually less than a third of the length of the scape, and the scape is very thin (0.4–0.9 cm in diameter). Flowering occurs January–February (TSU 2003).

The Shiny Grasstree is endemic to Tasmania and is distributed between Narawntapu National Park (NP) and Mount William in the north-east of the state (Tas. DPIW 2006h). This species is known from approximately 18 sites, however, many more probably occur on private land (Tas. DPIW 2006h). Its geographic range is approximately 100 km (Commonwealth of Australia 1999j). Bedford (1986) suggested a distribution that extended south to Hobart, however, these southern populations are likely to be Xanthorrhea australis.

The Shiny Grasstree is likely to have tens of thousands of plants, however the exact number is difficult to estimate due to identification confusion, the below-ground branching habit and few locations which have had numbers recorded (Tas. DPIW 2006h). The recovery plan for this species lists a number of locations (Tas. DPIW 2006h) and each of these locations are described as having "a number of sites" (Tas. DPIW 2006h). Important locations include (Tas. DPIW 2006h):

  • state forest at Badger Hill, about 990 plants
  • Little Boobyalla River Conservation Area, about 60 plants
  • Waterhouse Conservation Area
  • Bridport area
  • Cameron Regional Reserve
  • Mount William NP.

Other sites that have been identified include Commonwealth land at Stony Head Artillery Range (about 1000 plants) (Barker & Johnson 1998), Native Lass Lagoon (Johnson & Barker 1998), freehold land to be placed under secure conservation management (approximately 6000 plants) (TLC 2009), 500 plants near Tomahawk (Ziegler et al. 2005) and 'thousands' of plants near Ringarooma River (North Barker & Associates 2002).

The species is reserved in the Waterhouse Conservation Area, Mt William NP, Little Boobyalla River Conservation Area, Cameron Regional Reserve and Bridport Coastal Reserve (Tas. DPIW 2006h).

The Shiny Grasstree occurs in low-lying sandy coastal areas (Bedford 1986) where the sandy soils are often acid and waterlogged (Barker & Johnson 1998; Curtis & Morris 1994). Vegetation is often heathy Black Peppermint (Eucalyptus amygdalina) dry schlerophyll forest (Bedford 1986; Johnson & Barker 1998) These are fire-prone environments (Johnson & Barker 1998).

Flowering occurs in January–Febuary (Barker & Johnson 1998; Bedford 1986). The species can resprout from axillary buds and spreads vegetatively from underground rhizomes after fire or other gap-forming disturbance (Commonwealth of Australia 1999j).

Threatened Tasmanian Xanthorrhoea are perennial shrubs with greatly enhanced flowering after fire. The flowering trigger is not known, but it may be in response to competition, light, temperature or nutrient levels that vary post-fire (Tas DPIW 2006h).

The flowers of Xanthorrhoea species are thought to be insect pollinated. However, other fauna visit this plant in response to flowering including a range of birds such as honeyeaters (Meliphagidae) and wattlebirds (Anthochaera), as well as small mammals. Insect pollinators are thought to include ants (e.g. Formicidae), wasps (e.g. Encyrtidae), bees (e.g. Colletidae) and beetles (e.g. Chrysomelidae). The flower spike grows extremely fast. This fast growth is attributed to the fact that the scape becomes green and photosynthetic as it grows beyond the leaves (Tas DPIW 2006h).

Recruitment of Xanthorrhoea species is from seed, particularly following fire or soil disturbance. Seed germination occurs approximately 6–12 months after fire. Xanthorrhoea species are particularly slow growing, often taking hundreds of years to develop a trunk. Longevity of the threatened Tasmanian grasstrees requires investigation. The structure of grasstree populations indicates that recruitment is linked to episodic events. The seed appears to have short viability. Large amounts of seed are generally produced (2 seeds contained in each capsule on the flower spike) and germination is relatively easy, though in the wild correct conditions are needed. Research is required to determine what intensity of fire is most beneficial for flower production (Tas. DPIW 2006h).

Young seedlings are drawn into the ground by contractile roots, apparently to protect the vulnerable apex. The seedlings are extremely slow growing. Mature plants can live for up to 300 years. Established plants of the Shiny Grasstree are able to resprout after severe injury. Experiments with Xanthorrhoea australis indicate that decapitation of the plant is followed by axillary and adventitious root and shoot development. However, it is noted that not all Xanthorrhoea species would survive such damage. Foliage production increases after fire (Tas. DPIW 2006h).

The Shiny Grasstree is very similar to Xanthorrhoea australis and the Sand Grasstree (X. arenaria). At many sites, plants exhibit intermediate or combined characters of the species' (Johnson & Barker 1998). X. australis plants have a trunk whereas the other two are trunkless. Sand Grasstree has a flower spike greater than a third to less than half the length of the scape (flower stem) whereas the Shiny Grasstree has a flower spike less than a third of the length of the scape (Tas. DPIW 2006h).

The Shiny Grasstree is at risk of infection by Phytophthora cinnamomi, conversion of habitat, inappropriate fire regimes, over-harvesting of foliage and data deficiency due to their uncertain taxonomic status (Tas. DPIW 2006h).

Dieback caused by Phytophthora cinnamomi
Phytophthora cinnamomi is spread by running water and mud transported on footwear, vehicles and animal fur. There are several factors that increase the chance of disease infection and spread, such as low lying topography, close proximity to vehicular tracks and gravel roads, inappropriate road maintenance practices, infected gravel sources and bushwalkers (Barker 1994; Barker & Wardlaw 1995).The Shiny Grasstree is most abundant in coastal heathland sites, many of which sites suffer from infection by Phytophthora cinnamomi. Plants contained within forest communities may be less susceptible, particularly if they occur on drier sites that are topographically higher and naturally protected against floods.

Due to the nature of Phytophthora cinnamomi, the capacity for long term Xanthorrhoea conservation sites on Crown land is limited. There are few public reserves that do not have Phytophthora cinnamomi in the vicinity and most have little in the way of buffers surrounding populations. The north-east traditionally has high recreational off-road vehicle use, which is problematic when trying to contain Phytophthora cinnamomi. The potential threats are compounded by illegal woodcutting, which targets Black Peppermint forest communities. Increased support for management of threats is needed (Tas. DPIW 2006h).

Management on public land
For subpopulations on public land, Public Authority Management Agreements (a Tasmanian Government process) may be sought. These agreements are legally binding and involve the cooperation of two or more public authorities, such as Forestry Tasmania and the Tasmanian Department of Primary Industries and Water. Prescriptions agreed upon by both agencies can be consolidated and management responsibility then rests with the controlling authority (Tas. DPIW 2006h).

Management on private land
In order to secure long term management sites, agreements on private land are required. Securing private sites under management and conservation agreements would be more effective than those on public land, as access is generally far more restricted and often there is only one stakeholder involved in management decisions, rather than several. This of course relies on the interests of the landowner being compatible with the objectives of the plan and the availability of privately owned remnant vegetation patches with a suitable buffer to afford protection from Phytophthora cinnamomi (Tas. DPIW 2006h).

Over half the known threatened grasstree sites occur on private land and plants may be threatened by continuing land conversion, housing/development, habitat degradation, mining and trampling/grazing by stock. Private land owners need to be encouraged to participate in long-term conservation and management agreements in order to protect important populations, particularly those not, or minimally, infected by Phytophthora cinnamomi. In 2006, there were no significant threatened Xanthorrhoea populations contained in private reserves or areas protected by conservation covenant (Tas. DPIW 2006h).

Fire regimes
Although grasstrees require fire to induce mass flowering events, plants are potentially threatened by inappropriate fire frequencies that interrupt the maturation cycle and result in the death of individuals. Fire frequency and intensity needs to be such that plants can sufficiently develop to survive the burn, or reproduce to ensure that recruitment can occur. The effects of adverse fire regimes may be compounded by failure of seedling recruitment due to inappropriate germination conditions. Further research needs to be conducted in order to determine what disturbance regimes are most beneficial (Tas. DPIW 2006h).

Over-harvesting
Illegal collection of X. australis is a problem on mainland Australia. The collection of the Shiny Grasstree may be a problem in Tasmania, however, the threat is unquantified and may be minor because the Shiny Grasstree is trunkless (Tas. DPIW 2006h).

Taxonomic confusion
A major limiting factor for the protection of the Shiny Grasstree and the Sand Grasstree is their uncertain taxonomic status and the difficulty associated with identifying them in the field. Although the descriptions of the two species are quite different, in situ plants display intermediate characteristics between all three Tasmanian Xanthorrhoea species. The difficulty in identification may be due to hybridisation and introgression within the Tasmanian Xanthorrhoea group and confounded by the possible co-occurrence of taxa. The irregularity in flowering complicates matters further, as accurate identification requires a flower spike containing various floral features in good condition. Due to possible hybridisation events, even if one flower spike can be collected from a subpopulation it may not be representative of the group. Population data is therefore not entirely reliable and classification of these plants into groups by sites or localities is perhaps more relevant at this stage (Tas. DPIW 2006h).

Poor data quality
In 2006, due to the lack of data it is difficult to outline priority sites and subsequent management prescriptions. Estimates of plant numbers are required to prioritise management and monitoring is essential to determine the response of Xanthorrhoea to disease and whether, or to what extent, populations are in decline (Tas. DPIW 2006h).

Undertaken recovery actions
The National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tas. DPIW 2006h) identified a number of existing recovery measures.

The Shiny Grasstree was included as part of a Recovery Plan for Selected Tasmanian Forest Associated Plants (Barker & Johnson 1998), however, this plan has never been adopted or implemented (Tas. DPIW 2006h). In 2006, there was one land purchase under the 1999 Regional Forestry Agreement Private Forest Reserves Program that contains threatened Xanthorrhoea species (Tas. DPIW 2006h). The Shiny Grasstree occurs in Mt William NP, which is managed primarily for its nature conservation values. The species is included in the Waterhouse Conservation Area Management Plan 2003 (Tas. DPIW 2006h).

Management prescriptions against the spread of Phytophthora cinnamomi have been developed for threatened Xanthorrhoea sites at Badger Hill, Little Boobyalla, Mt William and the Waterhouse Conservation Area (for specific recommendations see Schahinger et al. 2003). If significant threatened Xanthorrhoea populations are discovered outside of these management areas, guidelines for assessing whether Phytophthora cinnamomi occurs at the site are available (Tas. DPIW 2006h). The Phytophthora cinnamomi Management Manual (Rudman 2004) provides detailed planning advice for whether an area should be managed for the pathogen. It also outlines management prescriptions for scenarios such as fire. This manual provides guidelines to identify priority management areas that were not recognised as part of the initial review (Schahinger et al. 2003). National threat abatement management protocols are also available (DEWHA 2009w).

Proposed recovery objectives
The National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tas. DPIW 2006h) identified a number of proposed recovery measures:

  • Prevent or minimise decline in known populations particularly with respect to management of Phytophthora cinnamomi.
  • Determine the extent of threatened grasstrees in Tasmania.
  • Develop a field-based identification system to enable appropriate management of all Tasmanian grasstrees.
  • Manage subpopulations in the long term.

Key management documents for this species include National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tas. DPIW 2006h) and the Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi (DEWHA 2009w).

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 National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].
Ecosystem/Community Stresses:Ecosystem Degradation:Decline in habitat quality National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].
Energy Production and Mining:Mining and Quarrying:Habitat destruction, disturbance and/or modification due to mining activities National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Vegetation and habitat loss caused by dieback Phytophthora cinnamomi National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species Species threats data recorded on the SPRAT database between 1999-2002 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012i) [Database].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery 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].
Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata) (Tasmanian Department of Primary Industries and Water (Tas. DPIW), 2006h) [Recovery Plan].

Barker, P.C.J. (1994). Phytophthora cinnamoni: The susceptibility and management of selected Tasmanian rare species. Hobart, Tasmania: Forestry Tasmania.

Barker, P.C.J. & K.A. Johnson (1998). Recovery Plan - Selected Tasmanian Forest Associated Plants. Hobart, Tasmania: Tasmanian Forestry.

Barker, P.C.J. & T.J. Wardlaw (1995). Susceptibility of Selected Tasmanian Rare Plants to Phytophthora cinnamomi. Australian Journal of Botany. 43:379-386.

Bedford, D. (1986). Xanthorrhoea. In: Flora of Australia. 46:148-169. Canberra: AGPS.

Commonwealth of Australia (1999j). Tasmanian Environment and Heritage Report, Regional Forest Agreement. Canberra, ACT: Department of Agriculture, Forestry and Fisheries.

Curtis, W M & D.I. Morris (1994). The Student's Flora of Tasmania Angiospermae: Alismataceae to Burmanniaceae. Hobart, Tasmania: St David's Park Publishing.

Department of the Environment (2014a). Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi. [Online]. Canberra; ACT: Department of the Environment. Available from: http://www.environment.gov.au/resource/threat-abatement-plan-disease-natural-ecosystems-caused-phytophthora-cinnamomi.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009w). Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi. [Online]. Canberra; ACT: Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/phytophthora.html.

Johnson, K.A. & P.J.C. Barker (1998). Management Prescriptions for Threatened Species on Public Land. Hobart, Tasmania: Forestry Tasmania.

North Barker & Associates (2002). Musselroe Wind Farm Proposed Transmission Line Corridor - Botanical Assessment. Page(s) 43. EPBC Referral 2002/683. North Barker & Associates Ecosystem Services for Hydro Tasmania.

Rudman, T. (2004). Interim Phytophora cinnamomi Management Guidelines. Hobart, Tasmania: Nature Conservation Branch, Department of Primary Industries, Water and Environment.

Schahinger, R., T. Rudman & T. Wardlaw (2003). Conservation of Tasmanian Plant Species & Communities threatened by Phytophthora cinnamomi. Strategic Regional Plan for Tasmania. Technical Report 03/03. Hobart, Tasmania: Nature Conservation Branch, Department of Primary Industries, Water and Environment.

Tasmanian Department of Primary Industries and Water (Tas. DPIW) (2006h). National Recovery Plan for Tasmanian Threatened Grasstrees (Xanthorrhoea arenaria and Xanthorrhoea bracteata). [Online]. Hobart, Tasmania: DPIW. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/x-arenaria-x-bracteata.html.

Tasmanian Land Conservancy (TLC) (2009). Creation of conservation covenant and sale of land for future residential development. EBPC Referral: 2009/4936. [Online]. Available from: http://www.environment.gov.au/cgi-bin/epbc/epbc_ap.pl?.

Threatened Species Unit (TSU) (2003). Threatened Flora of Tasmania - Xanthorrhoea bracteata. [Online]. Hobart, Tasmania: Department of Primary Industries, Water and Environment. Available from: http://www.dpiw.tas.gov.au/inter.nsf/Attachments/LJEM-76QVX7/$FILE/Xanthorrhoea%20bracteata.pdf.

Ziegler, K., P. Barker & A. North (2005). Proposed Dam, Un-named Western Tributary of Hardwickes Creek near Tomahawk - NE Tasmania - Vegetation Assessment. Unpublished report.

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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). Xanthorrhoea bracteata in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sat, 19 Apr 2014 11:19:17 +1000.