The North West Flinders Ranges Biological Survey aimed to systematically investigate and describe the variety of habitats supporting the vascular plant and vertebrate animal diversity of the region. Invertebrate animals were also collected from each sites but have not been analysed in this report. The study involved the collation of existing data combined with a field survey during December 1997. Thirty-three 1 km2 quadrats were chosen to reflect the diversity of habitats. Within these a total of 77 1 ha habitat patches were surveyed for vegetation. Thirty-two of the thirty-three quadrats were sampled for fauna (birds, reptiles and mammals) within the main habitat type for which each quadrat was chosen. Information gathered during the survey on the vegetation structure of each habitat, and data from over 100 Pastoral Assessment and Flinders Ranges Management Review sites were used to assist with the vegetation mapping of the area at a 1:100000 scale.
The survey identified 226 plant taxa bringing the total recorded for the area to 354. Twelve percent of these were introduced species. The plant associations sampled were clustered into 14 floristic groups based on similarity of species present at each site. These align themselves with four broad landform types: hills and ranges (4 groups); stony plains, undulating plains and low hills (5 groups); floodouts and drainage lines (4 groups); and dunefields (1 group). Average species richness at sites was 21. The study area was found to contain five species rated as having national conservation significance (Briggs & Leigh 1995), and a further three which are considered as having South Australian conservation significance.
The study area was known to have been visited by at least 159 species of bird, 93 of which were recorded during the survey. Cluster analysis of the bird fauna at the sites linked the six groups chosen to the four broad landform categories mentioned above. The most species rich site contained 19 species with the overall average of 8.5 species per site. Four species have national conservation significance (Garnett 1992) one of which is considered vulnerable to extinction (Thick-billed Grasswren). Thirty-seven species have South Australian conservation significance (Watts 1990).
The survey located 19 reptile species which had not been previously collected in the study area, bringing the total confirmed for the area to 50. Two additional species of snake (Pythons) were also reported by locals. Cluster analysis of the reptile assemblages at sites aligned six groups into the four broad landform categories mentioned previously. The most species rich sites contained 10 species with the overall average being 5.5 per site. Two of the species recorded represented significant extensions of their known range. Of the four frog species known to occur in the region two were located during the survey.
Thirteen species of native mammal were recorded for the study area. A further nine introduced mammals were also detected. The five small mammal species formed three assemblages aligned with three of the broad landform categories (sand dunes were not adequately sampled to reflect a true assemblage). Species richness was around 1 species per site - the maximum number at a site was three. The only species with a national conservation status is the Yellow-footed Rockwallaby which is currently the focus of a re-introduction and catchment management project. The two native rodent species recorded in the study area represent a significant contribution to our knowledge of native rodents in the Flinders Ranges.