Approved Conservation Advice for Tetratheca Glandulosa
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This conservation advice was approved by the Minister / Delegate of the Minister on 3 July 2008 Approved Conservation Advice (s266B of the Environment Protection and Biodiversity Conservation Act 1999). Approved Conservation Advice for Tetratheca glandulosa This Conservation Advice has been developed based on the best available information at the time this conservation advice was approved. Description Tetratheca glandulosa, Family Tremandraceae, is a low growing, spreading shrub, usually less than 20 cm high, but occasionally to 50 cm high (Thompson, 1976; Harden, 1992; Janet Cosh Herbarium, 2001). The dark pink, pale pink, white, or deep lilac pink flowers are mostly borne July to November (Harden, 1992; Janet Cosh Herbarium, 2001), and are likely to require native bees for pollination (DECC, 2005a). The species is cryptic (difficult to find), and rarely observed except while flowering (Janet Cosh Herbarium, 2001). Plants resprout from a woody root following fire and the plant is likely to be clonal (DECC, 2005a). Juveniles appear to be uncommon, with the majority of plants usually consisting of resprouting adults (DECC, 2005a). Conservation Status Tetratheca glandulosa is listed as vulnerable. This species is eligible for listing as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) as, prior to the commencement of the EPBC Act, it was listed as vulnerable under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). The species is also listed as vulnerable on the Threatened Species Conservation Act 1995 (NSW). Distribution and Habitat Tetratheca glandulosa is distributed around the Hawkesbury River, from Mangrove Mountain to the northern Sydney fringe suburbs, on the NSW Central Coast (Harden, 1992; Janet Cosh Herbarium, 2001). There are approximately 150 known populations ranging from Sampons Pass (Yengo National Park (NP)) in the north to West Pymble (Lane Cove NP) in the south (DECC, 2005a). The eastern limit is at Ingleside and the western limit is at East Kurrajong (Wollemi NP) (DECC, 2005a). There are historical collections of the species south to Manly, Willoughby and Mosman, however these populations are now extinct (DECC, 2005). The current north-south range is approximately 65 km (DECC, 2005a). Tetratheca glandulosa occurs within the Hawkesbury–Nepean, Hunter–Central Rivers and Sydney Metro (NSW) Natural Resource Management Regions. The species inhabits sandy or rocky heath or scrub (Thompson, 1976), dry woodland (Warringah Council, 2000; Janet Cosh Herbarium, 2001), open woodlands and open forest (DECC, 2005a). It occurs on ironstone gravel and shale substrates (RACAC, undated), on soil transitions between sandstone and shale (Janet Cosh Herbarium, 2001). Topographically, it occupies ridgetops, upper-slopes and to a lesser extent mid-slope sandstone benches (DECC, 2005a). It is sometimes found among rock platforms, adjacent to large areas of sandstone (NSW NPWS, 1999). Associated canopy species include Angophora bakeri, Corymbia gummifera, C. eximia, Eucalyptus capitellata, E. haemastoma, E. punctata, E. racemosa, and/or E. sparsifolia, and Banksia serrata, with an understorey dominated by species from the families Proteaceae, Fabaceae, and Epacridaceae (DECC, 2005a; RACAC, undated). The species is conserved in Garigal NP, Dharug NP, Ku-ring-gai Chase NP (Briggs & Leigh, 1996), Yengo NP (RACAC, undated), Wollemi NP, Lane Cove NP (DECC, 2005a), Marramarra NP (Janet Cosh Herbarium, 2001), Muogamarra Nature Reserve, Cattai NP, Tetratheca glandulosa Conservation Advice - Page 1 of 6 This conservation advice was approved by the Minister / Delegate of the Minister on 3 July 2008 Brisbane Water NP, Popran NP, Parr State Recreation Area and Berowra Valley Regional Park (NSW NPWS, 2000a). The distribution of the species overlaps with the following EPBC Act-listed ecological communities: • Shale/Sandstone Transition Forest, • Blue Gum High Forest of the Sydney Basin Bioregion, • White Box-Yellow Box-Blakely’s Red Gum Grassy Woodland and Derived Native Grassland, • Cumberland Plain Woodlands, and • Turpentine-Ironbark Forest in the Sydney Basin Bioregion. Threats The main identified threats to T. glandulosa include habitat loss from expanding urban areas; habitat degradation through fragmentation, fire, urban/agricultural runoff and stormwater and unrestricted access; illegal track creation; weed invasion; and trampling from people, horses (Equus caballus) and vehicles (Warringah Council, 2000; DECC, 2005a). Research Priorities Research priorities that would inform future regional and local priority actions include: • Undertake seed germination and/or vegetative propagation trials to determine the requirements for successful establishment. • Research the lifecycle, reproductive biology and seedbank dynamics (fecundity, viability, dispersal, longevity, dormancy etc) for this species (DECC, 2005b). • Research the role fire plays in seed germination and persistence of the species (DECC 2005a). Regional Priority Actions The following regional priority recovery and threat abatement actions can be done to support the recovery of Tetratheca glandulosa. Habitat Loss, Disturbance and Modification • Identify populations of high conservation priority. • Ensure chemicals or other mechanisms used to eradicate weeds do not have a significant adverse impact on T. glandulosa. • Ensure road/track widening and maintenance activities (and other infrastructure or development activities involving substrate or vegetation disturbance) in areas where the species occurs do not adversely impact on known populations. • Manage any changes to hydrology that may result in changes to the water table levels, increased run-off, sedimentation or pollution. • Investigate formal conservation arrangements such as the use of covenants, conservation agreements or inclusion in reserve tenure. Fire • Develop minimum fire frequency guidelines based on best available knowledge (DECC, 2005b). The species is thought to require fire no more than once every seven years (NSW RFS, 2004). • Develop and implement a suitable fire management strategy for T. glandulosa. Hazard reduction techniques should include slashing only to 100 cm and no tree removal or trittering (NSW RFS, 2004). • Provide maps of known occurrences to local and state rural fire services and seek inclusion of mitigative measures in bush fire risk management plans, risk register and/or operation maps. Tetratheca glandulosa Conservation Advice - Page 2 of 6 This conservation advice was approved by the Minister / Delegate of the Minister on 3 July 2008 Conservation Information • Raise awareness of Tetratheca glandulosa within the local community. • Develop guidelines for managing threats (DECC, 2005b). • Develop and implement site specific plan of management for high priority sites (DECC, 2005b). Enable Recovery of Additional Sites and/or Populations • Investigate options for linking, enhancing or establishing additional populations. • Implement national translocation protocols (Vallee et al., 2004) if establishing additional populations is considered necessary and feasible. • Undertake appropriate seed collection and storage. Local Priority Actions The following local priority recovery and threat abatement actions can be done to support the recovery of Tetratheca glandulosa. Habitat Loss, Disturbance and Modification • Monitor known populations to identify key threats. • Monitor the progress of recovery, including the effectiveness of management actions and the need to adapt them if necessary. • Control access routes to suitably constrain public access to known sites on public land. • Minimise adverse impacts from land use at known sites. • Ensure that sufficient vegetative buffers exist, during development in the vicinity of populations, to prevent habitat degradation and maintain habitat connectivity (DECC, 2005b). • Minimise habitat loss, particularly vegetation clearance within large populations and those at the edge of the species range (DECC, 2005b). Invasive Weeds • Identify and remove weeds in the local area, which could become a threat to T. glandulosa, using appropriate methods. • Manage sites to prevent introduction of invasive weeds, which could become a threat to T. glandulosa, using appropriate methods. Trampling, Browsing or Grazing • Prevent grazing and/or trampling pressure at known sites on leased crown land and in reserves using appropriate methods such as exclusion fencing or other barriers. Fire • Implement an appropriate fire management regime for local populations. • Ensure species is considered in planning of hazard reduction activities (DECC, 2005b). This list does not necessarily encompass all actions that may be of benefit to T. glandulosa, but highlights those that are considered to be of highest priority at the time of preparing the conservation advice. Existing Plans/Management Prescriptions Relevant to the Species • Garigal NP Fire Management Strategy (DEC, 2006a) and Plan of Management (NSW NPWS, 1998a), • Dharug NP Plan of Management (Griffin nrm, 2004; NSW NPWS, 1997a) and Fire Management Strategy (NSW NPWS, 2003), • Wollemi NP Fire Management Strategy (DEC, 2005) and Management Plan (NSW NPWS, 2001a), Tetratheca glandulosa Conservation Advice - Page 3 of 6 This conservation advice was approved by the Minister / Delegate of the Minister on 3 July 2008 • Ku-ring-gai Chase NP Management Plan (NSW NPWS, 2002) and Fire Management Strategy (NSW NPWS, 2006a), • Yengo NP and Parr State Conservation Area Plan of