van Etten & Fox: Vegetation classification - Hamerlsey Ranges 
emergent and characteristic mallee eucalypts such as E. 
trivalvis, E. socialis and, less commonly, E. repullulans. 
Average mallee cover is around 5%. Melaleuca 
eleuterostachya is by far the most common and 
characteristic shrub species present, with others such as 
Heliotropium sp. and A. bivenosa also found. This 
community was found on basic soils derived from 
calcareous parent rocks of the tertiary Oakover formation 
and older dolomites and shales such as those which 
predominate on the Jerrinah formation. 
Community 3B: Triodia wiseana hummock grassland with 
emergent Acacia xiphophylla and other Acacia spp. (on 
dolomitic and volcanic slopes and ridges; 5 sites). 
As with 3A, T. wiseana dominates this community. 
However the distribution of the grass is more patchy 
here as it gives way to relatively dense stands of A. 
xiphophylla (snakewood) and other acacias such as A. 
stowardii, A. victoriae and A. aneura. Dense stands of A. 
xiphophylla typically occur below major outcrops of 
calcrete bedrocks (breakaways) and are often mixed with 
A. aneura . The other acacias are found on more gentle 
slopes where the vegetation also typically contains 
numerous chenopod species, particularly of the genera 
M aireana and Sclerolaena. Considerable site to site 
variation in species composition was evident within this 
community with low homogeneity recorded (Table 3). 
Indicator species in addition to A. xiphophylla include 
Eremophila cuneifolia, M. georgeii and A. victoriae (Table 2). 
This community was found predominantly in the south¬ 
west of the study area where the geology and 
topography is more complex than elsewhere and 
includes outcrops of and soils derived from dolomites, 
dolerites, quartzites, basalts, shales and cherts, and 
sandstones. Further sampling of this community type is 
recommended to determine if it should be divided into 2 
types: 1) snakewood woodland on slopes below calcrete 
outcrops; and 2) mixed Acacia and chenopod shrubland 
on very alkaline soils. 
Subtype 4: Hummock grassland of Triodia wiseana with 
Acacia aneura or no/few emergent trees on a range of 
upland soils and landforms. 
Community 4A: Triodia wiseana hummock grassland with 
emergent Eucalyptus kingsmillii low mallee (on 
mountain tops; 7 sites). 
Eucalyptus kingsmillii is a small mallee characteristic of 
the summits of tall mountains of the Hamersley Ranges. 
Almost all mountain tops above approximately 1000 m 
have this community and it is rarely found at lower 
altitudes. T. wiseana is dominant, although T. bitextura is 
common at one site. Other eucalypts, such as E. 
leucophloia and E. ewartiana are found, but are sparse. 
Other common species vary with location; Acacia 
acradenia, Gompholobium polyzygum, A. ancistrocarpa, 
Olearia xerophila and Hibbertia glaberrima are examples of 
locally common indicator shrubs (Table 2). Callitris 
glaucophylla (cypress pine) is a fire sensitive tree found on 
steep slopes and other fire-excluded sites and is relatively 
common around mountain summits. 
Community 4B: Triodia wiseana hummock grassland with 
emergent, sparse Acacia inaecjuilatera and Eucalyptus 
leucophloia (on volcanic formations; 8 sites). 
This is another community dominated by the 
hummock grass T. wiseana. This community forms 
largely treeless hummock grassland; it has the lowest 
tree cover of all communities (Table 3). Trees, where 
present, are very sparse, with A. inaequilatera being the 
most widespread and common with an average of only 
1.1% cover. In some areas very sparse E. leucophloia trees 
also occur. The shrub layer is also sparse and mainly 
consists of acacias such as A. bivenosa, A. tetragonophylla 
and A. stowardii and subshrubs such as Ptilotus obovatus, 
P. rotundifolius , Sida echinocarpa and Solatium lasiophyllum. 
This community was mostly found on extensive volcanic 
plains. Volcanic formations of the study area are varied 
and include dolerite intrusions (such as the Weeli-Wooli 
formation) to more extensive areas of older (Archaean) 
basalts. Where outcropping of the volcanic rock is 
marked, other perennial grasses (particularly T. pungens, 
Cymbopogon ambiguus and Themeda triandra) are typically 
found in the interstices of rocks and boulders together 
with more specialised species such as Brachychiton 
gregorii , Hibiscus aff. coatsii and H. sturtii. Two sites not 
on volcanics were classified in this community probably 
because they were dominated by T. iviseana. These were a 
mountain top site (without the usual E. kingsmillii, but 
with low density of E. leucophloia) and a site on calcareous 
soils of the Jerrinah formation with scattered A. bivenosa 
shrubs. 
Community 4C: Acacia aneura woodland over Triodia 
iviseana hummock grass (on steep, scree slopes; 5 
sites). 
This community comprises dense stands of A. aneura 
(20-30% cover) over patchy T. wiseana and other 
perennial grasses such as T. triandra and E. mucronata. 
Broad leaved mulga (A. ayersiana) is also found. 
Subshrubs such as P. obovatus, Maireana villosa, Rhagodia 
eremaea and Sida spp. are relatively common. A range of 
indicator shrub species is also found, including 
Eremophila latrobei, Dodonaea viscosa, Sarcostemma viminale 
subsp. australe and A. rhodophloia (Table 2). This 
community is found on the steeper slopes of mountains 
and ridges where scree of ironstone formation covers the 
surface. 
Vegetation type 'M': mulga woodlands with grassy 
understorey on alluvial flats, fans and drainage lines. 
Mulga (Acacia aneura s.l.) dominates many of the plant 
communities of the valley systems within the Hamersley 
Ranges and is found, albeit at lower densities, in most of 
the other communities in low-lying areas. These areas 
typically feature the accumulation of fine alluvial soils 
washed down from the surrounding mountains and hills. 
Mulga woodlands are common vegetation types across 
the southern half of Australia's arid/semi-arid zones. A. 
aneura reaches its northern limit just north of the 
Hamersley Ranges (Beard 1975). 
Community 5 (also Subtype 5): Triodia melvillei hummock 
grassland with emergent Acacia aneura (on upper to 
mid bajada slopes; 13 sites). 
This community is characterised by dense hummock 
grass (T. melvillei) under a patchy stratum of A. aneura 
trees/shrubs. The density and cover of mulga is highly 
variable, but averages around 5-6%. Research in the 
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