Journal of the Royal Society of Western Australia, 87(2), June 2004 
"communities" at a broad (1:1 000 000) map scale (Beard 
1975) and several local, fine-scale studies of areas subject 
to mining developments, typically around 100 km 2 in 
extent (e.g. Trudgen & Casson 1998). Between these two 
extremes in scale, vegetation descriptions are absent. 
Furthermore, it is common for vegetation units in such 
studies to be defined subjectively and on the basis of 
physiognomy and dominant species, rather than overall 
floristic differences. This paper aims to fill this void by 
determining and describing vegetation types and 
communities in the central portion of the Hamersley 
Ranges using floristic data and multivariate methods. 
The degree to which vegetation units are floristically and 
spatially distinct will also be addressed. It is hoped that 
the vegetation classification and the methodology 
established here will form the basis for a classification 
scheme for the whole Hamersley Ranges region. Such a 
classification scheme would be of considerable benefit to 
those involved in conservation planning and impact 
assessment throughout the region, particularly as the 
amount of development is expected to increase 
dramatically over the next decade. 
Methods 
Study area 
The study area was located within the central portion 
of the Hamersley Ranges some 1100 km north of Perth, 
and was approximately 120 x 80 km in size (Fig 1). The 
area is dominated by Karijini National Park and is 
situated between the towns of Newman, Tom Price and 
Wittenoom (Fig 1). The Hamersley Ranges are located on 
the Hamersley Plateau, an extensive area which gently 
rises from north of the Ashburton River and ends in a 
sharp escarpment at the Fortescue River floodplain. The 
plateau surface lies 600-700 m above sea level. A series of 
east to west trending ranges and associated hills and 
mountains rise above the plateau a further 200 to 600 m. 
Characteristic landforms of the region are similar to those 
of other mountainous deserts (Cooke et al. 1993) and 
include: 1) slopes of hills, ridges and mountains; 2) 
pediment slopes (slopes of sorted colluvium at the base 
of hills, ridges, etc.); 3) bajada slopes (coalesced alluvial 
fans below pediments); 4) alluvial flats and broad 
drainage lines; 5) confined streams and creeklines; and 6) 
cuesta (scarp and dip slope topography) (Lorimer 1991). 
The surface geology of the Ranges is dominated by 
ironstones on the uplands and, in the broad valley 
systems, various formations of colluvium and alluvium. 
Ironstones date from the lower Proterozoic era when 
layers of iron rich sediment are believed to have been 
deposited while the area was inundated by sea (Twidale 
& Campbell 1991). A number of ironstone formations 
occur in the Ranges and they typically alternate with 
layers of dolomite and shale. In addition to these 
sedimentary rocks, Archaean (basement) granites and 
gneiss are found, predominantly in the south of the study 
area. Volcanic intrusions (mainly dolerite sills) are also 
Figure 1 . Location map showing the study area in relation to regional and State features. 
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