1.1.7.2 Terrestrial species and communities

Northern SA and southern NT, and in particular the Lake Eyre Basin, is made up of three dominant landscape or environment types:

The area is recognised for being part of the driest area in Australia, however its diverse flora and fauna are not generally appreciated (Brandle, 1998).

The stony or gibber deserts of the Lake Eyre Basin were first described to the European settlers by Captain Charles Sturt following his search for the great inland sea during the mid 1840s

(Sturt, 1849). The stony deserts north-west of Kati Thanda – Lake Eyre were traversed 50 years later (1894) by the Horn Natural History Expedition (Spencer, 1896).

Systematic descriptions of parts of the Assessment area began with botanists. Jessup (1951) described the habitats of substantial areas to the west of Kati Thanda – Lake Eyre, and produced some structural vegetation community maps. This work and the efforts of Murray (1931) and Crocker (1946) with the aid of soil maps of Northcote et al. (1968) soil maps, provided the groundwork for much of Specht’s synthesis of the vegetation communities of SA (Specht, 1972).

There have been numerous specific biological surveys in the areas comprising the Pedirka and Arckaringa subregions. The earliest was an undergraduate student project in the Breakaways Reserve area to the south (Hobbs, 1987). The Department for Environment undertook a survey of the Tallaringa Conservation Park prior to its dedication (Robinson et al., 1988) in the sandy areas to the west. The Australian & New Zealand Scientific Exploration Society undertook two surveys in the hills of Arckaringa Station to the north-east (ANZSES, 1994, 1995). The stony plains and breakaways to the east and north-east were sampled in 1995 as part of the Biological Survey of the Stony Deserts (Brandle, 1998). This survey sought to systematically sample the central Australian gibber country, the bulk of which occurs in the South Australian portion of the Lake Eyre Basin, and to draw together information gathered about similar land types in adjacent areas of other states. A number of quadrats were also sampled in 1992 on Evelyn Downs Station adjacent to the north-east of Mount Willoughby as part of a threatened species project, the results of which were included in Biological Survey of the Stony Deserts (Brandle, 1998). The Biological Survey of the Anangu-Pitjantjatjara Lands sampled the hard mulga and sand country to the north and north-west in 1996 and 1998 (Robinson et al., 2003).

More recently, a biological survey and vegetation mapping of the Mount Willoughby IPA was undertaken to assist the management of the area for biodiversity and management planning. The Sandy Deserts Survey (including Simpson, Pedirka and eastern portions of the Great Victoria Desert) contributed a vast amount of data and vegetation mapping (J. Foulkes, in prep.). Similarly, the Arid Rivers Survey (creeks and floodplains in western Lake Eyre Basin) undertook vegetation and fauna sampling (including fish) (DEWNR, unpublished).

Other work in the region has come in the form of a conservation management appraisal of the former Mount Dare Station, which resulted in its purchase for the Witjira National Park (Davey et al., 1985) and other more specific studies. For example, there have been ongoing investigations into the springs since a major overview of the vegetation, fish and invertebrates was produced in 1985 (McLaren et al., 1985). A number of species-specific studies that have been published are listed in the introductions to the various chapters. Davies (1995) published a report dealing with the management of several threatened plant species populations in the area.

Two books summarising much of the known natural history of the Lake Eyre Basin in SA, including stony desert habitats, have also been published. The Natural History of the North-east Deserts (Tyler et al., 1990) provides scientific summaries, while A Natural History of the Lake Eyre Region (Badman et al., 1991) is written as a visitor’s guide to the region (see also three volume set Lake Eyre South published by Royal Geographical Society).

1.1.7.2.1 Threatened species

Using data sourced from the Biological Database of SA and Atlas of living Australia, the distribution of threatened flora and fauna for the Pedirka subregion is shown in Figure 39 to Figure 42 . It should be noted that these databases do not include all data collected in the region, particularly aquatic species monitoring records (e.g. Cockayne et al., 2012, 2013). All records from sites within a 5 km buffer of the subregion are displayed. Species are displayed as having a conservation ranking if they have a threatened status of critically endangered, endangered, vulnerable or rare under the following:

The location of other species records for the relevant biotic group (‘non-rated species’) are displayed (black dots) to indicate the distribution of survey sites across the subregion and level of survey effort. As can be seen from the maps, surveys generally follow roads and tracks and less data are available for sites away from roads and tracks. Survey methods, including site selection, are provided in survey reports.

The density of significant species is displayed using a grid of cells to indicate whether a point indicates a single record or multiple records for that location. The total number of significant species surveys within each grid cell can include records of the same or different species, at the same or a nearby location, and on one or more occasion.

Conservation rankings are provided in Table 6 .

Table 6 Conservation ratings and abbreviations under the National (EPBC Act 1999), South Australian (SA NPW Act 1972), Northern Territory (TPWC Act 2000) or regional level (Outback Region, Gillam and Urban 2013)

Reptiles

Within the Pedirka subregion, 116 taxa from 10 families have been recorded. There is a single EPBC rated reptile species, the Bronzeback Legless Lizard (Ophidiocephalus taeniatus), which is also rated Rare at the state level and Vulnerable at the regional level. It is endemic to the western Lake Eyre Basin and is confined to dense leaf litter in drainage lines in mulga woodlands. There are four taxa rated Rare at the state level and one Vulnerable. Regionally, the Short-tailed Pygmy Monitor and Bronzeback Legless Lizard are rated Rare and Vulnerable respectively (Table 7). Figure 39 shows the distribution of rated species records within each rating category and the density of rated species records within 1 km² grid cells.

Table 7 List of reptiles with conservation status ratings at the National (EPBC Act), South Australian (SA NPWS Act), Northern Territory (TPWCA 2007) or regional level (Outback NRM Region) recorded within the Pedirka subregion

^aWetland, drainage-line or floodplain dependant taxa are indicated

Figure 39 Significant reptile sites within and near the Pedirka subregion

Birds

Within the Pedirka subregion, approximately 200 taxa from 61 bird families have been recorded. Of these, 80 taxa from 39 families have a National (EPBC – 4 taxa), State (SANPW Act – 42 taxa), NT (15 taxa, including 5 extinct) or Regional (Outback NRM Region (71 taxa) conservation status rating (Table 8). Figure 40 shows the distribution of rated species records within each rating category and the density of rated species records within 1 km² grid cells. There are a number of locations predominantly on the western half of the subregion where up to 74 records of rated bird taxa per 1 km² grid cell are recorded, with many centred on drainage lines.

Forty-two species are waterbirds (including migratory birds) or birds dependent on wetlands or riparian systems for breeding or roosting (Table 8).

Table 8 List of birds with conservation status ratings at the National (EPBC Act), South Australian (SA NPWS Act), Northern Territory (TPWCA 2007) or regional level (Outback NRM Region) recorded within the Pedirka subregion

^aWetland, drainage-line or floodplain dependent taxa are indicated

Figure 40 Significant bird sites within and near the Pedirka subregion

Mammals

Within the Pedirka subregion, 44 native taxa have been recorded from 13 families. Of these, 18 taxa from 8 families have a National (EPBC ‑ 13 taxa- 4 extinct), State (SANPWS ‑ 17 taxa (including 6 extinct in SA), NT (TPWCA 15 taxa) or Regional (Outback NRM Region-14 taxa (including 8 regionally extinct) conservation status rating (Table 9 and Figure 41). Figure 43 shows the distribution of rated species records within each rating category and the density of rated species records within 1 km²grid cells. There are a number of locations predominantly on the western half of the subregion where up to 20 records of rated mammal species per 1 km²grid cell are recorded.

Three taxa (Hairy-nosed Freetail-bat, Plains mouse and Common Brushtail Possum) are reliant on riparian or floodplain systems as a major part of their habitat or for breeding or roosting (Table 9).

Table 9 List of mammals with conservation status ratings at the National (EPBC Act), South Australian (SA NPWS Act), Northern Territory (TPWCA 2007) or regional level (Outback NRM Region) recorded within the Pedirka subregion

^aWetland, drainage-line or floodplain dependant taxa are indicated. ^bTaxa known from sub-fossil only

Figure 41 Significant mammal sites within and near the Pedirka subregion

Flora

Within the Pedirka subregion, approximately 1250 taxa from 88 vascular plant families have been recorded. Of these, 113 taxa from 39 families have a National (EPBC – 2 taxa), State (SANPWS – 30 taxa) NT (4 taxa) or Regional (Outback NRM Region (101 taxa)) conservation status rating (Table 10). Figure 42 shows the distribution of rated species records within each rating category and the density of rated species records within 1 km²grid cells. The highest density of rated plant taxa records (20 records in a 1 km² grid cell) is in a band south-west of Finke across the SA border, with other locations around Andado.

More than 40 taxa from 20 families occur in wetland, drainage-line and or halophytic habitats, including the one of the EPBC rated taxa, Frankenia plicata (Endangered) (Table 10).

Table 10 List of vascular plants with conservation status ratings at the National (EPBC Act), South Australian (SA NPWS Act), Northern Territory (TPWCA 2007) or regional level (Outback NRM Region) recorded within the Pedirka subregion

^aWetland, drainage-line or floodplain dependent taxa are indicated

Figure 42 Significant flora sites within and near the Pedirka subregion