Biodiversity Assessment - Stony Plains
Stony Plains
Introduction
Arid stony silcrete tablelands and gibber and gypsum plains with sparse low chenopod shrublands over short-lived tussock grasses on duplex soils and calcareous earths. Eucalyptus coolabah ssp. arida (coolibah) and E. camaldulensis (River red gum) woodlands on cracking clays fringe the channels and floodplains of large arid drainage systems that dissect these landforms. Chenopod shrublands and perennial tussock grasslands are common on the floodplains themselves. The Stony Plains bioregion comprises five subregions (Breakaways - STP1, Oodnadatta - STP2, Murnpeowie - STP3, Peake-Denison Inlier - STP4 and Macumba - STP5).
Summary of overall condition and trend
The overall condition of the bioregion is fair and the trend static. The principal land use is grazing of native pastures. Pastoral properties in this bioregion mainly stock cattle, though sheep predominate in the southern portion, south of the dog fence. Historical species decline has been related to fox and feral cat predation and habitat degradation associated with grazing by introduced herbivores. The pastoral lease assessment and monitoring program is currently addressing the issue of total grazing pressure, and is a major initiative in pastoral land management and restoration. Subregions are continental landscape stress class 3 and 4 as assessed by the Landscape Health report (1 is most stressed, 6 is least stressed).
Summary of Conservation Priorities
The protection and management of mound springs is a significant priority for conservation in this bioregion. Biologically, mound springs are truly oases in the desert as they provide habitat for many distinctive and endemic flora, vertebrate and invertebrate species. Few are within formally protected areas, though the South Australian Department for Environment and Heritage has maintained a vegetation monitoring program at ten fenced springs for over ten years.
The control of discharge and distribution of artesian water is also a priority as unrestricted flows can reduce water availability elsewhere in the Great Artesian Basin (GAB). This in turn can impact on mound springs and pastoral production. Related to this is the issue of the creation of new stock water points in previously ungrazed or lightly grazed areas and how it impacts on native species.
Natural values
The Stony Plains bioregion contains a diverse range of habitats including dissected tablelands and arid ranges, dune and floodplain systems, as well as the more extensive gibber plains. This diversity is reflected in the abundance of reptile taxa present. More than 100 species have been recorded in these habitats, of which four - Gibber Dragon (Ctenophorus gibba), Ochre Dragon (C. tjantjalka), Bronze-backed Legless-lizard (Ophidiocephalus taeniatus) and Woomera Slider (Lerista elongata) - are endemic to the bioregion. The area also provides primary habitat for many others.
At least 13 plant species are also endemic to the bioregion. These include Ptilotus barkeri (Barker's mulla mulla), Othonna gypsicola (gypsum groundsel), Embadium johnstonii (Johnston's slipper plant) and Stemodia haegii (Haegi's stemodia).
A major feature of the bioregion is the many mound springs that occur extensively along the southwest boundary of the Great Artesian Basin.
Click here to link to a table of natural values within each subregion
Wetlands
Freshwater springs or oases are the only wetland type covered by the two nationally important wetlands in the bioregion. These are Dalhousie Springs and Lake Eyre Mound Springs. Both of these are significant examples of wetlands in an arid environment and of natural discharge from the Great Artesian Basin. Dalhousie Springs comprise the largest artesian springs in Australia and the Lake Eyre Mound Springs are excellent geological examples of mound spring formation.
The condition of both is fair and the trend is presumed static. The main threatening processes are excessive water extraction elsewhere in the Great Artesian Basin, tourism pressure, off road vehicles, weed invasions (eg date palms at Dalhousie) and grazing and trampling by feral animals and stock.
More mound spring complexes are recognised as significant at the subregional level, though the lack of detailed biological information for many of these represents a major knowledge gap.
Several inland watercourses and seasonal freshwater swamps in the Northern Territory section of the bioregion are also significant.
Nationally important wetlands
Map: IBRA map showing DIWA locations, towns, subregions, major roads and reserves and most common threatening processes.
Click here to link to a table of Australia's Important Wetlands (Directory of Important Wetlands of Australia): their type, condition, trend and threatening processes within each subregion.
Regionally important wetlands
Table: Provisional identification of wetlands of regional significance: their type and special values within each subregion. The reliability of the overall subregional assessment is indicated.
There is no data available for this table within the bioregion.
Table: Provisional identification of wetlands of regional significance: their condition, trend and threatening processes within each subregion.
There is no data available for this table within the bioregion.
Riparian Zones
Several major arid watercourses either traverse or drain the stony tablelands and gibber plains. The Stevenson, Macumba, Alberga, Neales, Arckaringa and Peake Creeks all drain the western margin of the Lake Eyre Basin and flow southeast toward Lake Eyre North. Further south the Margaret Creek flows toward Lake Eyre South. There are few major watercourses in the Murnpeowie subregion in the southeast apart from Frome Creek. This flows north from the Flinders Ranges to the southern end of Lake Eyre North.
All are in fair condition and the trend static. The major threats are feral animals and total grazing pressure.
Click here to link to a table of riparian zones: their average condition, trend and threatening processes for each subregion. The reliability of this overall assessment is indicated.
Ecosystems at risk
Four ecosystems have been assessed as being at risk within the bioregion. The only endangered ecosystem is the 'Communities associated with Mound Springs'. Hemichroa mesembryanthema +/- Maireana pyramidata +/- M. astrotricha +/- Atriplex vesicaria +/- samphires Low Shrubland in saline soils of broad shallow depressions surrounding mound springs is also associated with these features. The mound springs are spread across most of the bioregion, from Dalhousie Springs in the far north to near Lake Callabonna in the southeast. The other two threatened ecosystems are arid acacia woodlands that also have a wide distribution.
All are declining in condition. The dominant threats to mound spring ecosystems are a reduction in flow due to excessive extraction of artesian water, grazing and trampling by feral animals and stock, weed invasions and tourism. The arid acacia woodlands are threatened by lack of regeneration and suppression of seedlings by introduced herbivores, particularly rabbits and camels.
Map: IBRA map showing frequency of threatening processes for ecosystems.
Click here to link to a table of provisional list of threatened ecosystems in Australia: their broad vegetation type (National Vegetation Information System - Major Vegetation Subgroup), recommended status, current legislative protection as a threatened ecosystem, trend and bioregional distribution. These ecosystems are arranged in the bioregion of their principal occurrence. The reliability of the recommended status is indicated.
Click here to link to a table of provisional list of threatened ecosystems in each subregion: their threatening processes.
Click here to link to a table of provisional list of threatened ecosystems in each subregion: their recommended recovery actions
Species at risk
The main threats to the plants are total grazing pressure (and possibly trampling), lack of recruitment and, for mound springs plants such as Eriocaulon carsonii (salt pipewort), reduced water flows resulting from excessive extraction of artesian water. The mammals are threatened by habitat disturbance associated with feral animals and cattle, altered fire regimes, competition for resources with introduced herbivores and predation from foxes and feral cats. In addition to these same threats the birds also face low level hunting and ground nesters are at particular risk to breeding disturbance. As the preferred habitat of the single threatened reptile, Ophidiocephalus taeniatus (Bronze-backed Legless-lizard), is the breakaway country, current land use poses little threat. Available habitat is likely only to be reduced if new stock water points or mining extraction were to increase utilisation of the area.
There is a total of 24 threatened species in the Stony Plains. These are made up of:-
| Taxa Group | Commonwealth Rating | State/Territory Rating | |||
|---|---|---|---|---|---|
| Endangered | Vulnerable | Endangered | Vulnerable | Total | |
| Plants | 3 | 0 | 0 | 8 | 11 |
| Birds | 0 | 2 | 0 | 7 | 9 |
| Mammals | 0 | 3 | 0 | 0 | 3 |
| Reptiles | 0 | 1 | 0 | 0 | 1 |
| Amphibians | 0 | 0 | 0 | 0 | 0 |
| Total | 3 | 6 | 0 | 15 | 24 |
Map: IBRA map showing frequency of threatening processes for species.
Click here to link to a table of species at risk in each subregion: their status, trend and subregional distribution. The reliability of the assessment of trend is indicated and whether recovery plans have been prepared.
Click here to link to a table of species at risk in each subregion: their threatening processes.
Click here to link to a table of species at risk in each subregion: their status recommended recovery actions.
Eucalypts and Acacias
No subregions in this bioregion contain endemic eucalypts or acacias. Nor are there any that have been identified as being particularly rich for these genera.
Birds
The gibber of the Stony Plains is not particularly good habitat for birds, and the bioregion is only moderately important even for Gibber Birds. A number of other limited range species characteristic of chenopod shrublands do occur there, although even the moderate importance of the bioregion for these species is possibly inflated because most of the habitat is relatively unrewarding for birdwatching. No threatened species were recorded, and there were only a few records of exotic taxa. Although the area was slightly wetter than average during both Atlas periods, the reporting rate of freshwater species fell severely to a level comparable to that in the adjacent Simpson-Strzelecki Dunefields.
Status: Relatively small arid-adapted bird fauna except for ephemeral wetlands.
Rare and threatened: No major populations.
Increasers: None indicative of landscape health.
Indicators: Emu, Australian Bustard, Banded Lapwing, White-browed Treecreeper, Jacky Winter, Hooded Robin.
Trend: Decrease in reporting rate of freshwater species and migratory waders.
Scenario: Overgrazing of chenopod shrublands has happened in the past but current avifauna now largely stable within the wide range of climate-driven variation.
Actions: No grazing in representative areas and the adoption of reduced, conservative grazing rates in key habitat across the bioregion.
Click hereto download a summary report including the physical characteristics of the bioregion, a species list, and summary statistics [Excel file]. The file may open on your screen. To save it to your system 'Save as' under the File menu.
Mammals
Number of species and status
There are 50 mammal species within this bioregion. (The maximum number of species recorded in a bioregion is 86 and the minimum is 25).
Click here to link to a table of number of species in each status class for this bioregion.
Click here to link to a list of mammal species and their status for this bioregion.
Critical weight range
The critical weight range (35 - 5500 g) of mammals is the size range of Australian mammals that have been most affected by environmental changes following European settlement. In this bioregion, the proportion of mammal fauna within the critical weight range is .5. (The maximum proportion of fauna within the critical weight range recorded in a bioregion is 0.632 and the minimum is 0.222).
Faunal Attrition Index
Faunal attrition is a measure of contraction or loss of species richness with a region. A high index value means many species have declined or are extinct in the bioregion. The index can be used to compare the status of mammal fauna to regional attributes such as changes since European settlement and average annual rainfall. The Faunal Attrition Index for mammals in this bioregion is .41. (The maximum faunal attrition index value recorded in a bioregion is 0.66 and the minimum is 0).
Click here to link to a table of Faunal Attrition Index for groups of mammals shows the contributions of each group to overall patterns of faunal decline.
Faunal Contraction Index
A range contraction index is a measure of the extent to which the range inhabited by a particular species has contracted. A high index value means that many of the species comprising the region's original mammal fauna have contracted from a high proportion of the regions they originally occurred in. The faunal contraction index for the mammal fauna in this bioregion is .4. (The maximum faunal contraction index value recorded in a bioregion is 0.51 and the minimum is 0.07).
Faunal Endemism Index
Endemic species are those restricted to certain regions. Regions containing endemic species are considered to have high biodiversity conservation values because opportunities to conserve those species do not exist elsewhere. A high index value means that the species comprising the original mammal fauna typically occurred in few bioregions. The faunal endemism index value for the mammal fauna in this bioregion is .66. (The maximum faunal endemism index value recorded in a bioregion is 0.79 and the minimum is 0.52).
New Endemism Index
Extant (still surviving) species that have undergone major range contractions can be considered 'new endemics'. Bioregions that contain new endemic species are often important refugia for threatened species. The new endemism index for the mammal fauna in this bioregion is .69. (The maximum new endemism index value recorded in a bioregion is 0.93 and the minimum is 0.5).
Table: Translocated Species
There is no data available for this table within the bioregion.
Exotic Mammals
The number of introduced exotic mammal species that occur within this bioregion is 10. (The maximum number of introduced exotic mammal species in a bioregion is 16 and the minimum is 5).
Click here to link to a list of introduced exotic mammal species for this bioregion.
Extinct mammal species
The number of extinct mammal species that previously occurred within this bioregion is 14. (The maximum number of extinct mammal species in a bioregion is 29 and the minimum is 0).
Click here to link to a list of extinct mammal species for this bioregion.
Management responses
Reserve consolidation
There are several major reserves within the bioregion:
- Witjira National Park protects mound springs of the Dalhousie Complex and a wide range of desert habitats including gibber plains, stony tableland, sand dunes and floodplains on the western margin of the Simpson Desert.
- Wabma Kadarbu Mound Springs Conservation Park is a small reserve that protects the mound springs of Blanche Cup Springs, the Bubbler and Coward Springs.
The only additional reserves in the bioregion are very small sections of Lake Eyre and Gammon Ranges National Parks and two small Heritage Agreements at Coward Springs and Evelyn Downs.
Protection of further mound springs is required as these highly significant landforms are insufficiently represented in the existing reserves. Priority landscapes for reservation include:-
- Moon Plain near Coober Pedy, an area of ephemeral sub-shrublands and herblands on cracking clay with little water;
- breakaway country of the Arckaringa Hills; and
- Davenport and Peake Denison Ranges, which contain a number of restricted habitats and species population isolates.
Priority subregions for reserve consolidation are Peake-Denison Inlier (currently unreserved), Oodnadatta (0.1% protected) and Murnpeowie (0.6% protected). The main constraints are availability and cost of suitable areas, and the competing land use of pastoralism.
Click here to link to a table of comprehensiveness, adequacy and representativeness (CAR) of the National Reserve System in terms of ecosystems and area sampled and a ranking of reserve management. The bioregional priority for consolidating the National Reserve System is based on this CAR analysis and threat.
Click here to link to a table of bioregional and subregional priorities and ecosystem priorities to consolidate the National Reserve System and associated ecosystem constraints.
Off-park conservation for species and ecosystem recovery
The group most in need of recovery actions is those species and ecosystems associated with mound springs. This includes two ecosystems and two plant species, plus fish, isopods, amphipods, ostracods and hydrobiid molluscs.
A number of major recovery actions have already been implemented including fencing springs on pastoral land, a long term vegetation monitoring program at fenced sites, rabbit proof fencing at two springs and trial burns of Phragmites australis (common reed) to enable Eriocaulon carsonii to recolonise spring vents.
The main constraints are the presence of feral animals and the competing need to maintain pastoral production.
Integrated NRM
Key issues for integrated natural resource management in the Stony Plains are:-
- the maintenance of flows at mound springs and the protection of ecosystems associated with them;
- the uncontrolled discharge and distribution of artesian water;
- feral animal control; and
- the creation of new stock watering points in previously ungrazed or lightly grazed areas.
Current NRM initiatives include:-
- NHT-funded Bushcare Grants for on-ground biodiversity conservation works;
- a duty of care requirement for pastoral lessees within the Pastoral Land Management and Conservation Act 1989 that details their obligations to land management; and
- several major planning mechanisms - Marla-Oodnadatta Soil Conservation District Plan, Marree Soil Conservation District Plan, Lake Eyre Basin Strategic Plan and the Great Artesian Basin Strategic Management Plan.
The priorities for NRM across the bioregion are:-
- establishment of Heritage Agreements on pastoral leases to protect more of the mound springs;
- ensure ongoing funding for on-ground biodiversity conservation works;
- feral animal control - aerial shoots of camels, horses and donkeys; and
- rip rabbit warrens at key sites.
Map: IBRA map showing frequency of recovery actions (species).
Map: IBRA map showing frequency of recovery actions (ecosystems).
Map: IBRA map showing existing projects part of NRM.
Click here to link to a table of contribution of integrated Natural Resource Management to the protection of biodiversity in each subregion: existing measures and effectiveness.
Table: The contribution of integrated Natural Resource Management to the protection of biodiversity in each subregion: feasible opportunities and comments.
There is no data available for this table within the bioregion.
Further Information & Gaps
Data gaps and research priorities
The main gaps in knowledge are riparian condition, detailed biological information on all the mound springs, threatening processes for many of the threatened plants, and condition and trend information for all threatened species.
References
Environment Australia 2000. Revision of the Interim Biogeographic Regionalisation of Australia (IBRA) and the Development of Version 5.1. - Summary Report. Department of Environment and Heritage, Canberra.
A complete list of references is available by clicking here.
Further information
View the Landscape Health in Australia report.
View the Terrestrial Biodiversity Assessment 2002 report.
Download the Terrestrial Biodiversity Assessment 2002 Database - Biodiversity Audit Data Entry System (BADES), and specifications
Click here to link to a table of some major data gaps in each subregion in terms of protecting biodiversity.
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