Natural Temperate Grassland of the Southern Tablelands of NSW and the Australian Capital Territory.

Advice to the Minister for the Environment and Heritage from the Endangered Species Scientific Subcommittee (ESSS) on a proposal to add an ecological community to Schedule 2 of the Endangered Species Protection Act 1992 (ESP Act)

Ecological community name

Natural Temperate Grassland of the Southern Tablelands of NSW and the Australian Capital Territory.

Description

The community is dominated by moderately tall (25-50 cm) to tall (50 cm-1 m), dense to open tussock grasses with up to 70% of species being forbs. The community may be treeless or contain up to 10% cover of trees, shrubs or sedges. In the Southern Tablelands natural temperate grasslands are located at altitudes between 560 and 1200 metres in valleys influenced by cold air drainage and in broad plains. The community occurs within the geographical region of the Southern Tablelands of NSW and ACT, which extends southwards from the Abercrombie River to the Victorian Border, from Boorowa and Jindabyne to the west and Goulburn to Braidwood and Bombala to the east.

Listed Species in the proposed ecological community

The conservation status of threatened grassland species in natural temperate grassland communities in the Southern Tablelands against IUCN categories, ANZECC listing of conservation status, the Endangered Species Act 1992 (C'th.), the Nature Conservation Act 1980 (ACT) and the Threatened Species Conservation Act 1995 (NSW) are as follows:

Species Common Name IUCN ANZECC Commonwealth ACT NSW
Perunga ochracea Perunga Grasshopper       V  
Synemon plana Golden Sun Moth       E E
Aprasia parapulchella Pink tailed Worm lizard   E E   V
Delma impar Striped Legless Lizard V     V V
Suta flagellum Little Whip Snake         V
Tympanocryptis lineata pinguicolla Grassland Lined Earless Dragon V E   E E
Ammobium craspedioides Yass Daisy   V     V
Calotis glandulosa Mauve Burr   V V   V
Dodonaea procumbens Creeping Hopbush         V
Prasophyllum petilum a leek orchid   E   E E
Rutidosis leiolepis Monaro Golden   V V   V
Rutidosis leptorrhynchoides Button Wrinklewort   E E E E
Swainsona recta Small Purple   E E E E
Thesium australe Austral Toadflax   E V   V
E: endangered; V: vulnerable

A number of species occur in natural temperate grassland sites in the Southern Tablelands either in low densities per site, or in very few sites within the region. While some of these species may not necessarily be confined to the temperate grassland community, it is possible that they will become endangered in the community should the threatening processes continue to operate. Examples are:

  • Yam Daisy or Murnong (Microseris lanceolata), which is very poorly represented in the NSW and ACT Southern Tablelands grassland sites;
  • Golden Moths (Diuris chryseopsis), an orchid found in very few sites in the ACT and NSW Southern Tablelands; and
  • Hairy Buttons (Leptorhynchus elongatus), which is recorded in about eight sites in the region in NSW.

Further examination of unpublished fauna and flora survey data are expected to reveal more species with very low and declining population densities in the lowland temperate grasslands of the Southern Tablelands.

Description of the community `Natural Temperate Grassland of the Southern Tablelands of New South Wales and the Australian Capital Territory' sufficient to distinguish it from any other ecological community

The community is distinguished by the dominant cover of native tussock grasses, particularly Themeda australis (Kangaroo Grass), Austrodanthonia spp. (Wallaby Grasses), Austrostipa (Spear Grasses) and Poa spp. (Tussock Grasses) (Benson 1994, Sharp 1997). About 70% of the species present are forbs, comprising mainly daisies, lilies and native legumes growing in intertussock spaces. Many of the forb species are ephemeral or annual (Costin 1954). Shrubs and trees are sparse or absent due to influences of cold air drainage, with minimum ground temperatures often below 10 C (Sharp 1997).

Key attributes influencing community composition and structure are fluctuating temperature conditions and low rainfall, and the low nutrient, heavy textured soils that are characterisitc of the region (Costin 1954, Groves and Lodder 1991). In the Southern Tablelands the community is found between 560 and 1200 metres in altitude, primarily in the valleys and lower slopes, and on the broader plains (Sharp 1997, Rehwinkel 1997). Natural temperate grassland integrades on the slopes with grassy woodland (defined as having a tree cover between 10% and 30% (Mott and Groves 1994)). The community is differentiated from the treeless alpine communities by species composition and position in the landscape.

Floristic associations have been defined for the community, based on position in the landscape, drainage and soil characteristics (Sharp 1997). Of these, five are present in the ACT (Sharp 1997), and a further three associations have been defined for the Monaro (Benson 1994). They are recognised by their dominant flora, structure and characteristic native plant species. Several faunal species also are found primarily or only within defined associations (ACT Government 1997a, 1997b, 1997c; 1998).

Evidence that the description of the community `Natural Temperate Grassland of the Southern Tablelands of New South Wales and the Australian Capital Territory' is conventionally accepted

Natural temperate grassland is conventionally accepted as an ecological community in scientific literature (eg Moore 1964; Groves and Williams 1981; Kirkpatrick et al. 1995; Mott and Groves 1994). The community is defined by the dominance by tussock grasses, particularly of the genera Themeda, Poa and Austrostipa (syn. Stipa); presence of forbs; and with a distribution within south-eastern Australia where the annual average rainfall is between 500 and 1000 mm (Mott and Groves 1994).

Natural temperate grassland in the Southern Tablelands is recognised as an ecological community that is distinguishable from natural temperate grassland elsewhere in south-eastern Australia (McDougall and Kirkpatrick 1993; Benson 1994; Kirkpatrick et al. 1995).

Reasons why the community `Natural Temperate Grassland of the Southern Tablelands of New South Wales and the Australian Capital Territory' is considered to be endangered within the meaning of Section 6 of the Act

The community fits criteria 2 a, c and e for the following reasons:

  1. Decline in extent and fragmentation of sites:
    • clearing for agricultural development or plantation forestry;
    • clearing for urban infrastructure development or rural residential development; and
    • continuing fragmentation of sites.
  2. Modification of the community composition, structure and processes through:
    • severe infestation and modification of habitat by invasive exotic species, particularly Serrated Tussock (Nassella trichotoma), African Lovegrass (Eragrostis curvula) and St John's Wort (Hypericum perforatum) and several pasture species including Phalaris (Phalaris aquatica);
    • neglect resulting from non-recognition of the values of the sites;
    • lack of sympathetic management, eg. inappropriate grazing regimes leading to degradation of conservation values; and
    • loss of species diversity and richness and presence of threatened fauna and flora.

The community is listed in the ACT as an endangered ecological community (ACT Government 1997a) and similar natural temperate grassland communities are listed as threatened communities in Victoria (ACT Government 1997a). In NSW grassland communities are only afforded limited protection: on the Monaro under the Monaro Grasslands Management Plan under SEPP no.46, and state-wide under the definition of "groundcover" in the Native Vegetation Conservation Act, 1997.

Past and current distributions of `Natural Temperate Grassland of the Southern Tablelands of New South Wales and the Australian Capital Territory'

It is estimated that 20 000 ha of natural temperate grassland occurred in the ACT prior to European settlement. Approximately 1000 ha (5%) containing the ecological community now occurs in moderate to good condition and a further 500 ha of low botanical significance is also found, providing buffers or protecting grassland habitat for threatened species, in a total of 39 locations in the ACT (ACT Government 1997a). Most of the sites occur as small urban remnants and roadsides, but several large (over 100 ha) sites still remain, of which the majority is Commonwealth land, mainly managed by Department of Defence.

In the Southern Tablelands of NSW it is estimated that 450 000 ha of natural temperate grassland occurred prior to European settlement (Benson 1994). About 2400 ha (0.6%) containing the ecological community in moderate to good condition on public lands and some private lands has been surveyed (Rehwinkel 1997). Possibly the same amount again occurs on private lands not as yet surveyed (Rehwinkel pers. comm.). This gives an estimated total of up to 1.5% of the pre-European distribution of this community remaining in moderate to good condition in NSW Southern Tablelands, and possibly another 5% in poorer condition (native pastures of relatively lower forb diversity and high exotic content).

The past distribution of this community in the Southern Tablelands in NSW, as mapped by Costin (1954), Pryor (1938) and Rehwinkel (1997), is now represented by isolated examples of sites with high to very high conservation value. Benson (1994) provides an overview of the extent and quality of remnants on the Monaro. Benson's work has been extended by others (e.g. Rowell 1994; Rehwinkel 1996a, 1996b, 1996c, 1996d).

In the northern section of the region some significant sites have been identified, but they represent a very small proportion of the natural temperate grasslands that existed there at the time of European settlement (Rehwinkel 1995, 1996e, 1998 in prep.). For example, there is only one site remaining of high integrity of each of the extensive Bungendore-Hoskinstown, Yass and Gundary plains. Other small sites representing the previous extent of the grasslands across the northern part of the region are confined to travelling stock reserves and roadsides in valleys subject to cold air drainage (Rehwinkel 1998 in prep., unpublished data).

In the ACT there are four reserved sites, containing a total area of 206 ha of grassland (a total of 13.7% of the remaining area, and 1% of the pre-European extent). A further 345 ha within six sites are now protected under Memoranda of Understanding developed between various Commonwealth agencies, Environment ACT and Environment Australia.

In NSW there are two proposed nature reserves totalling some 200 ha (a total of 0.8% of the remaining area and 0.05% of the pre-European extent). Other sites in NSW are being considered for secure reservation. Placing high conservation lowland temperate grassland sites under some form of reservation, whether that be establishment of nature reserves, crown reserves, voluntary conservation agreements or joint management agreements, will abate the processes threatening the sites.

References that support information given in the nomination

ACT Government (1997a) Natural temperate grasslands: an endangered ecological community. Action Plan No. 1. Environment ACT, Canberra.

ACT Government (1997b) Striped Legless Lizard (Delma impar): a vulnerable species. Action Plan No. 2. Environment ACT, Canberra.

ACT Government (1997c) Eastern Lined Earless Dragon (Tympanocryptis lineata pinguicolla): an endangered species. Action Plan No. 3. Environment ACT, Canberra.

ACT Government (1998) Golden Sun Moth (Synemon plana): an endangered species. Action Plan No. 7. Environment ACT, Canberra.

Benson, J. (1994) The native grasslands of the Monaro region: Southern Tablelands of NSW. Cunninghamia 3 (B) 609-650.

Costin, A. (1954) A study of the ecosystems of the Monaro Region of NSW. Government Printer, Sydney.

Groves, R.H. & Williams, O.B. (1981) Natural Grasslands. In Groves, R.H. (ed) Australian Vegetation, pp 293-316. Cambridge University Press, Cambridge.

Groves, R.H. and Lodder M (1991) Flora of the ACT's natural grasslands. In Falconer R. (ed.) The ACT's Native Grasslands, pp 7-10. Proceedings of a workshop, February 1991. Conservation Council of the South-East Region and Canberra.

Kirkpatrick J, McDougall K. and Hyde M. (1995) Australia's Most Threatened Ecosystems the southeastern lowland native grasslands. Surry Beatty & Sons, Chipping Norton, NSW.

McDougall, K and Kirkpatrick, J.B. (1993) Conservation of lowland native grasslands in south-eastern Australia. World Wide Fund for Nature, Sydney.

Moore C.W.E. (1964) Distribution of grasslands. In Barnard, C. (ed) Grasses and grasslands, pp 182-205. Macmillan, London.

Mott J.J. and Groves R.H. (1994) Natural and Derived Grasslands. In Groves R.H. (ed.) Australian Vegetation (2nd ed.), pp 369-392. Cambridge University Press, Cambridge.

Pryor L.D. (1938) Vegetation Map of the ACT. Dept of Interior, Canberra.

Rehwinkel, R. (1995) Preliminary survey of Letchworth grasslands for assessment of conservation values. Unpublished report, National Parks and Wildlife Service.

Rehwinkel, R. (1996a) Draft report of the significant native grasslands of the Snowy River Shire. Unpublished report, National Parks and Wildlife Service.

Rehwinkel, R. (1996b) Draft report of the significant grasslands on travelling stock reserves in the Cooma Rural Lands Protection Board District. Unpublished report, National Parks and Wildlife Service.

Rehwinkel, R. (1996c) The Monaro and Southern Tablelands Grassland Conservation Project. Unpublished report, National Parks and Wildlife Service and ANCA.

Rehwinkel, R. (1996d) Preliminary survey of the grassland at "Oakley" (portion 7, Parish of Mitta Mitta, Eurongilly NSW) for assessment of conservation values. Unpublished report, National Parks and Wildlife Service.

Rehwinkel, R. (1996e) Preliminary survey of the Turallo Range Grassland (Crown Land part of Portion 208, Parish Majura, Bungendore NSW) of assessment of conservation values. Unpublished report, National Parks and Wildlife Service.

Rehwinkel, R. (1997) Grassy ecosystems of the South Eastern Highlands - Technical Report. Stage 1, Joint regional biodiversity survey of grassy ecosystems of the South Eastern Highlands Project. Report to ACT P&CS, PALM, HIA, NCA, NSW NPWS.

Rehwinkel, R (1998) Conservation assessment of grasslands and grassy woodlands on travelling stock reserves of the Goulburn Rural Lands Protection Board A report for the Goulburn Rural Lands Protection Board, NSW NPWS and Environment Australia.

Rehwinkel, R (in prep.) Conservation assessment of grasslands and grassy woodlands on travelling stock reserves of the Yass Rural Lands Protection Board A report for the Yass Rural Lands Protection Board, NSW NPWS and Environment Australia.

Rowell, A. (1994) A study of the native grasslands of the Monaro District A report for the New South Wales National Parks and Wildlife Service and the Department of Planning (Heritage Assistance Program).

Sharp S.B. (1997) Diversity, patterns and processes of vegetation and invertebrate orders in natural temperate grasslands in the Australian Capital Territory. M.App.Sc. thesis, University of Canberra.