This Conservation Advice was approved by the Minister / Delegate of the Minister on: 1/10/2008 Approved Conservation Advice (s266B of the Environment Protection and Biodiversity Conservation Act 1999) Approved Conservation Advice for Pterostylis cobarensis (Cobar Greenhood Orchid)
This Conservation Advice has been developed based on the best available information at the time this Conservation Advice was approved; this includes existing plans, records or management prescriptions for this species.
Description Pterostylis cobarensis, Family Orchidaceae, also known as Cobar Greenhood Orchid, is a terrestrial orchid with 7–11 narrow-elliptic leaves which form a basal rosette, each 1.5–2.5 cm long and 5–8 mm wide. Three to eight flowers grow on stems up to 40 cm high, with 3–5 closely sheathing stem leaves. Flowers are transparent with brown and green markings, each flower about 1.2 cm long. Flowering occurs from September to November. Vegetative reproduction is not common in this group of Greenhoods, but some species may form more than one daughter tuber annually. Plants are deciduous and die back to the large, underground tubers after seed release. New rosettes are produced following soaking autumn and winter rains. Pterostylis cobarensis is pollinated by the males of small gnats which are attracted to the flower by some pseudosexual perfume (DECC, 2008a).
Conservation Status Cobar Greenhood Orchid 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). Cobar Greenhood Orchid is also listed as vulnerable under the Threatened Species Conservation Act 1995 (NSW).
Distribution and Habitat Cobar Greenhood Orchid is known chiefly from the Nyngan–Cobar–Bourke district in the far western plains of NSW. Recorded localities include Narrabri, Nyngan, Cobar, Nymagee, Mt Gundabooka, Mt Grenfell, and Mutawintji National Park. It has also been located in the Darling Downs district of Queensland and the eastern part of South Australia (EPA, 2003; DECC, 2008; CPBR, 2008). There is no information on the size of individual populations; however, some populations have been described as abundant to occasional. The species inhabits eucalypt woodland, open mallee, or Callitris shrubland on low stony ridges and slopes with skeletal sandy-loam soils. Associated species include Eucalyptus morrisii, E. viridis, E. intertexta, E. vicina, Callitris glaucophylla, Geijera parviflora, Casuarina cristata, Acacia doratoxylon, Senna spp., and Eremophila spp. (DECC, 2008a). Cobar Greenhood Orchid occurs within the Central West, Namoi, Western (NSW) Border Rivers Maranoa–Balonne, Condamine (Queensland), and South Australia Arid Lands Natural Resource Management Regions. The distribution of this species overlaps with the following EPBC Act-listed threatened ecological communities: • Semi-evergreen vine thickets of the Brigalow Belt (North and South) and Nandewar Bioregions, • Brigalow (Acacia harpophylla dominant and co-dominant), • White Box-Yellow Box-Blakely’s Red Gum Grassy Woodland and Derived Native Grassland, and • Buloke Woodlands of the Riverina and Murray-Darling Depression Bioregions. Pterostylis cobarensis Conservation Advice - Page 1 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 1/10/2008 Threats The main identified threats to Cobar Greenhood Orchid are damage caused by feral goats (Capra hircus); broad-scale vegetation clearing; grazing pressure (ANRA, 2007a); changed hydrology increasing salinity; fragmentation; and loss of remnants (ANRA, 2007b). The main potential threats to the species include habitat degradation (granite ridge and rocky slope habitat are particularly vulnerable to erosion caused by feral goats); and weed invasion (DECC, 2008a).
Research Priorities Research priorities that would inform future regional and local priority actions include: • Design and implement a monitoring program or, if appropriate, support and enhance existing programs. • Develop a collection program (including mycorrhizal symbiont) in collaboration with the Sydney Botanic Gardens Trust (DECC, 2008b). • Investigate seed and symbiont viability, germination, dormancy and longevity (in natural environment and in storage) (DECC, 2008b). • Conduct experimental research into ecological requirements and the effects of fire and grazing disturbance (DECC, 2008b). • Conduct a comprehensive survey within the expected range of the species to determine the full extent of its current distribution (DECC, 2008b).
Regional Priority Actions The following regional priority recovery and threat abatement actions can be done to support the recovery of Cobar Greenhood Orchid. 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. • Identify populations of high conservation priority. • Ensure road widening and maintenance activities (or other infrastructure or development activities) involving substrate and vegetation disturbance in areas where Cobar Greenhood Orchid 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, and salinity • Investigate formal conservation arrangements, management agreements and covenants on private land, and for crown and private land investigate inclusion in reserve tenure if possible. Conservation Information • Raise awareness of Cobar Greenhood Orchid within the local community by distributing information regarding the species, its threats and management actions to assist in the location and protection of further populations. Enable Recovery of Additional Sites and/or Populations • Collect seed and soil/mycorrhizal fungi for NSW Seedbank. • 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.
Pterostylis cobarensis Conservation Advice - Page 2 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 1/10/2008 Local Priority Actions The following local priority recovery and threat abatement actions can be done to support the recovery of Cobar Greenhood Orchid. Habitat Loss, Disturbance and Modification • Control access routes to suitably constrain public access to known sites on public land. • Suitably control and manage access on private land. • Minimise adverse impacts from land use at known sites. Invasive Weeds • Identify and remove weeds in the local area, which could become a threat to Cobar Greenhood Orchid, using appropriate methods. • Manage sites to prevent introduction of invasive weeds, which could become a threat to the species, using appropriate methods. Trampling, Browsing or Grazing • Manage known sites to ensure appropriate grazing regimes occur. • Implement the management plan for the control and eradication of feral goats, especially in reserves (EA, 1999; DECC, 2008b). • Protect populations from feral goats and other grazing pressure through fencing (DECC, 2008a). • Develop and implement a stock management plan for roadside verges and travelling stock routes. • Monitor the effect of grazing from native herbivores (DECC, 2008b).
This list does not necessarily encompass all actions that may be of benefit to Cobar Greenhood Orchid, but highlights those that are considered to be of highest priority at the time of preparing the conservation advice.
Existing Plans/Management Prescriptions that are Relevant to the Species • Threat Abatement Plan for Competition and Land Degradation by Feral Goats (EA, 1999), • Upper Darling Region - Pest Management Strategy (NPWS, 2003), and • A Vegetation Management Plan for Areas Invaded By Native Trees and Shrubs in the Cobar Peneplain (CVMC, 2006). These prescriptions were current at the time of publishing; please refer to the relevant agency’s website for any updated versions.
Information Sources: Australian Natural Resources Atlas (ANRA) 2007a, Biodiversity Assessment – Broken Hill Complex, viewed 27 May 2006,
Pterostylis cobarensis Conservation Advice - Page 3 of 4 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 1/10/2008 Department of Environment and Climate Change New South Wales (DECC) 2008b, Pterostylis cobarensis – priority actions, viewed 27 May 2008,
Pterostylis cobarensis Conservation Advice - Page 4 of 4