Thelymitra sp. Kangaloon - critically endangered species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the terrestrial orchid Thelymitra sp. Kangaloon (D.L.Jones 18108) as a critically endangered species in Part 1 of Schedule 1A of the Act. Listing of Critically Endangered species is provided for by Part 2 of the Act.

 

The Scientific Committee has found that:

 

1. Thelymitra sp. Kangaloon (D.L.Jones 18108) is a sun orchid and has the manuscript name Thelymitra kangaloonica Jeanes in Jones (2006), where it is described as having: “leaf 150-350 x 5-25 mm, thick. Flower stem 200-560 x 2-3.5 mm, 2-15-flowered. Sterile bracts 2-3, large, lowest bract leaf-like. Flowers 15-30 mm across, deep blue with darker veins, externally brownish. Sepals and petals 8-18 x 4-8 mm. Column 5.5-6.5 x 2.5-3.5 mm, white to pale blue; post-anther lobe 1.5-2.5 x 1.5-2 mm, yellow with dark purple collar, curved, slender, notched, lobes toothed; column arms 1.5-2.3 mm long, obliquely erect; hair-tufts mop-like, dense, white, with hairs 1-1.6 mm long.”

 

2. Thelymitra sp. Kangaloon is only known to occur on the southern tablelands of NSW in the Moss Vale / Kangaloon / Fitzroy Falls area at 550-700 m above sea level. It is thought to be a short-lived perennial, flowering in late October and early November. It is found in swamps in sedgelands over grey silty grey loam soils (DEWHA 2010). It is known to occur at three swamps that are above the Kangaloon Aquifer, and that are a part of the ecological community “Temperate Highland Peat Swamps on Sandstone” which is listed under the Environment Protection and Biodiversity Conservation Act 1999.

 

3. Four populations of Thelymitra sp. Kangaloon have been recorded, although only two are known to be extant following partial inundation of two sites. The majority of known plants are located on land managed by the Sydney Catchment Authority. One small population is located in Budderoo National Park. The extent of occurrence of Thelymitra sp. Kangaloon, encompassing the four recorded locations, is estimated to be 134 km2 based on a minimum convex polygon, the recommended measure for extent of occurrence in the IUCN (2010) guidelines. However, as there are doubts about the current existence of two of the four recorded populations, the extent of occurrence is likely to be less than 100 km2, and the geographic distribution of Thelymitra sp. Kangaloon may be considered to be very highly restricted. The area of occupancy for the four known populations is 16 km2, equivalent to four 2x2 km grids, the recommended measure for AOO in the IUCN (2010) guidelines.

 

4. Whilst there are limited estimates of the abundance of Thelymitra sp. Kangaloon, using a precautionary approach, it is likely that the number of mature individuals of Thelymitra sp. Kangaloon is very low, with less than 250 plants known.

 

5. The alteration of and disturbance to the habitat of Thelymitra sp. Kangaloon are the main threats to the orchids’ survival. The swamp habitat is dependent on the existing water flows, and alteration of water flows is a threat to the Temperate Highland Peat Swamps on Sandstone ecological community (DEWHA 2010). Thelymitra sp. Kangaloon is potentially threatened by the extraction of water from the Kangaloon aquifer beneath the swamps. Longwall coal mining beneath the swamp habitat is also a potential threat (TSSC 2008b). Other threats include inappropriate fire regimes, grazing, illegal collection of the orchids, and hydrological changes from road works and suburban development (TSSC 2008b). The future drying out of swamps from climate change is also a potential threat to the species. ‘Alteration of habitat following subsidence due to longwall mining’, ‘Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands’ and ‘Anthropogenic Climate Change’ are listed as Key Threatening Processes under the Threatened Species Conservation Act 1995.

 

6. A decline in the habitat of Thelymitra sp. Kangaloon has occurred in the recent past. It is calculated that the known habitat for Thelymitra sp. Kangaloon has declined by more than 50% in recent years due to disturbance at two of the sites. The extent of one location was reduced by approximately 60% due to draining of the swamp, and another was reduced to approximately 20% of its original area due to inundation from the Fitzroy Falls Reservoir (TSSC 2008a).

 

7. Thelymitra sp. Kangaloon (D.L.Jones 18108) is eligible to be listed as a Critically Endangered species as, in the opinion of the Scientific Committee, it is facing an extremely high risk of extinction in New South Wales in the immediate future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation, 2010:

 

Clause 7 Restricted geographic distribution and other conditions

The geographic distribution of the species is estimated or inferred to be:

(a)

very highly restricted,

and either:

(d)

a projected or continuing decline is observed, estimated or inferred in either of the key indicators:

 

(a)

an index of abundance appropriate to the taxon, or

 

 

(b)

the geographic distribution, habitat quality or diversity, or genetic diversity of the species.

 

 

Clause 8 Low numbers of mature individuals of species and other conditions

The estimated total number of mature individuals of the species is:

(a)

very low,

and either:

(d)

a projected or continuing decline is observed, estimated or inferred in either of the key indicators:

 

(a)

an index of abundance appropriate to the taxon, or

 

 

(b)

the geographic distribution, habitat quality or diversity, or genetic diversity of the species.

 

 

Dr Richard Major

Chairperson

Scientific Committee

 

Gazettal date: 28/10/11

Exhibition period: 28/10/11 – 20/01/12

 

References:

 

Department of the Environment, Water, Heritage and the Arts (2010). Thelymitra sp. Kangaloon (D.L.Jones 18108) in Species Profile and Threats Database, Department of the Environment, Water, Heritage and the Arts, Canberra. Available from: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=81971

 

IUCN (2010) ‘Guidelines for Using the IUCN Red List Categories and Criteria Version 8.0.’ Prepared by the Standards and Petitions Working Group. IUCN Species Survival Commission Biodiversity Assessments Sub-Committee, Gland.

 

Jones DL (2006) A complete guide to native orchids of Australia, including the island territories. Sydney, NSW: Reed New Holland.

 

Threatened Species Scientific Committee (TSSC) (2008a). Commonwealth Listing Advice on Thelymitra sp. Kangaloon (D.L.Jones 18108). [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81971-listing-advice.pdf

 

Threatened Species Scientific Committee (TSSC) (2008b). Commonwealth Conservation Advice on Thelymitra sp. Kangaloon (D.L.Jones 18108). [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/81971-conservation-advice.pdf.

Page last updated: 28 October 2011