The Koolanooka Hills occur in the IBRA Avon Wheatbelt (AW1) subregion of the
Southwest Botanical Province (Western Australian Herbarium, 2008). This active ancient
drainage subregion in the Yilgarn Craton has a rich endemic flora on lateritic uplands within
a cover of proteaceous scrub-heaths. The region is relatively close to the intersecting
Transitional Rainfall Zone between the South-Western and Eremaean Botanical Provinces of
Western Australia (Beecham, 2001). The Transitional Rainfall Zone, that includes most of
the wheatbelt, is regarded as a focal point for speciation in woody perennial plants and has a
nationally significant concentration of endemic plants at the species level (Aussie Heritage,
eucalypt woodlands like Salmon Gum, Gimlet, York Gum and Red Morrel) and associated
mallee (Natural Resource Management, 2007). Sheoak (Allocasuarina) and Jam (Acacia
acuminata) woodlands dominate on quaternary alluvials and elluvials (Australian
Government, 2007). Other vegetation communities that occur in the Avon Wheatbelt include
salt lakes, shrubland and kwongan (an aboriginal name for low heath like vegetation)
communities (NRM, 2007). Native vegetation in the region is recognised internationally for
its species richness and high levels of endemism.
Beard (1976) classified the vegetation of the Koolanooka System and included it in the
Greenough Region in the Irwin Botanical District. This district is in the southern Murchison
Region of the Southwestern Botanical Province (Beard, 1976).
The plant assemblages of the Koolanooka Hills System contain a number of ecosystems that
are classified as at risk and have been defined as a threatened ecological community (TEC)
and listed as Vulnerable. The vegetation of these areas is dominated by sheoak and mixed
shrubland of Allocasuarina campestris (hilltops) and Acacia exocarpoides (on granite).
Three land systems are associated with the Koolanooka area;
Koolanooka Land System (comprises the Koolanooka Hills)
Noolagabbi Land System (associated with the level and gently inclined flats and lower
slopes surrounding the Koolanooka Land System and is often associated with a saline
drainage network); and
Pindar Land System (associated with the gently undulating sandplain with long, gentle
Blue Hills lie within the South-western Interzone, a marginal area in the southern Murchison
Region occurring at the boundary of the Irwin and Austin Botanical Districts (Beard, 1976).
Blue Hills is in the Yalgoo sub-region of the Austin Botanical District within the Eremaean
Province (Western Australian Herbarium, 2008). The Yalgoo Botanical Province is
characterised by low woodlands to open woodlands of Eucalyptus, Acacia and Callitris on
red, sandy plains. (Desmond and Chant, 2001).
In Beard’s vegetation classification (1976), the Yalgoo subregion is a transitional area of the
Eremaean Province where the vegetation is mostly Eremaean in character but with a slight
shift due to an increase in rainfall. The major vegetation types of the Yalgoo subregion
include heath on granite outcrops (Borya, Thryptomene, Baeckea and Calycopeplus), Acacia
scrub (Acacia acuminata, A. ramulosa and A. quadrimarginea), Acacia-Melaleuca thicket
(Acacia ramulosa, A. acuminata, Melaleuca uncinata with variations, including M.
nematophylla), scrub with scattered trees (Acacia ramulosa, A. acuminata, Hakea preissii,
Eucalyptus loxophleba, E. oleosa, Callitris columellaris, Bursaria spinosa and A. aneura)
and salt flats (surrounded by samphire e.g. Halosarcia spp., teatree e.g. Melaleuca /
The vegetation of the Yalgoo subregion becomes lower and denser towards the South-
western Botanical Province as Acacia aneura (mulga - adapted to intermittent rainfall) starts
to disappear and is replaced by other Acacia species.
No TECs are listed as occurring in the Yalgoo bio-region.
THE GENERAL AREA
The vegetation associated with the Koolanooka System is described as consisting of several
vegetation types (Beard, 1976). Vegetation Type 1 comprises open woodland of sheoak
(referred to by Beard, by the synonym Casuarina huegeliana [Allocasuarina huegeliana],
however this is treated as cf. (refer to the interpretation) Allocasuarina acutivalvis in a recent
report by Meissner and Caruso (2006), as there are no WA Herbarium records for A.
comprises Eucalyptus loxophleba (York Gum) woodland interspaced with the same thicket,
which forms the vegetation pattern on the footslopes of Koolanooka Hills, while the granite
outcrops support mixed Acacia spp. (A. tetragonophylla, A. quadrimarginea and A.
Five plant assemblages of the Koolanooka System are listed as TECs by the DEC. Beecham
(2001) lists these TECs as:
shrubs (such as Acacia spp.) and emergent mallees on shallow red loam over massive
ironstone on steep rocky slopes;
Eucalyptus ebbanoensis subsp. ebbanoensis mallee and Acacia spp. scrub with
scattered Allocasuarina huegeliana (cf. Allocasuarina acutivalvis, see above) over
red loam and ironstone on the upper slopes and summits;
Eucalyptus loxophleba woodland over scrub on the footslopes; and,
mixed Acacia spp. scrub on granite.
The Koolanooka Hills TEC occurs over two areas, Koolanooka Hills and Perenjori Hills and
covers approximately 5419 ha (M. Morley, DEC, pers. comm., 18
December 2006). The
vegetation data by DEC has shown that the vegetation at Koolanooka Hills is significantly
different from that at Perenjori Hills (Meissner and Caruso, 2006).
Adjacent to Rothsay in the south of the Yalgoo subregion, steep ridges of Archaean
metamorphic banded ironstone rocks occur, and these include the Blue Hills. These
formations are covered with shrublands of Acacia quadrimarginea and A. acuminata that are
generally dominated by A. ramulosa, Casuarina sp., and Melaleuca uncinata, sometimes
with scattered trees of Eucalyptus loxophleba and Allocasuarina dielsiana (syn. Casuarina
Four vegetation units associated with a single topographic feature, the flat / plain, were
recorded during the survey. These vegetation types are detailed in Table 3.1. Vegetation
typical of the Koolanooka System TEC as described by Beard was not encountered during
Table 3.1: Vegetation units encountered at Koolanooka during the survey
Vegetation encountered at site KWB01 and along
open shrubland over scattered herbs and
Vegetation encountered at site KWB02.
shrubland over very open mixed herbs and
Vegetation encountered at site KWB03.
open woodland over Acacia acuminata high
shrubland over Acacia paraneura open
shrubland over Grevillea levis low open
shrubland over open mixed herbs.
*Note, this site was located at the rifle range
vegetation description was derived from the
vegetation surrounding the cleared area.
Vegetation encountered at the proposed access track
from KWB02 to an existing fence line track.
Eucalyptus ebbanoensis subsp. ebbanoensis
medium mallee shrubs over Acacia
and Eremophila oldfieldii subsp. oldfieldii tall
open shrubland over Acacia acanthoclada
mixed herbs and scattered soft grasses.
Three vegetation types associated with two topographic features, minor gully base and flat /
plain, were recorded during the survey. These vegetation types are detailed in Table 3.2.
The vegetation along the track leading to these sites was the same as that recorded at the
proposed drill pads.
Table 3.2: Vegetation units encountered at Blue Hills during the survey
Vegetation encountered at WB01 – flat plain.
subsp. hesperia shrubland.
Vegetation encountered at WB02 – minor gully base.
woodland over Melaleuca nematophylla high
open shrubland over Acacia sibilans open
shrubland over Baeckea sp. Mt Gibson (R.
Meissner & Y. Caruso MTGB16), Aluta
aspera subs. hesperia and Drummondita
microphylla low shrubland.
Vegetation encountered at WB03 – minor gully base .
and Acacia ramulosa var. ramulosa low
woodland over Drummondita microphylla,
Hibbertia arcuata and Aluta aspera subsp.
hesperia low shrubland over scattered herbs
and soft grasses.
Forty three taxa from 23 families and 31 genera were recorded during the survey and none of
these was a weed species (Appendix B). Of these taxa, one was identified to family level and
one to genus level only.
Thirty three taxa from 21 families and 27 genera were recorded during the survey and none
of these was a weed species (Appendix B).
FLORA OF CONSERVATION SIGNIFICANCE
4.1.1 Environment Protection and Biodiversity Conservation Act 1999
Flora species are protected at a National level under the Commonwealth Environment
species that are considered Critically Endangered, Endangered, Vulnerable, Conservation
Dependent, Extinct or Extinct in the Wild (for definitions of categories, see Appendix C).
A search of the Department of Water and Heritage database was conducted using a 30 km
buffer around the centre of each survey area. The results for both areas are outlined below.
Four species of nationally threatened flora are known from the vicinity of the Koolanooka
project area (Table D.1, Appendix D) (Dept of the Environment, Water Resources and the
Arts, 2008); Eremophila viscida, (Endangered), Frankenia conferta (Endangered),
None of these taxa was recorded during the current survey.
One species of nationally threatened flora is known from the vicinity of the Blue Hills project
area (Table D.2, Appendix D); Eremophila viscida (Endangered) (Dept of the Environment,
Water Resources and the Arts, 2008). However, Eucalyptus synandra has been collected
from John Forrest Lookout and along the Emu Fence track on Karara Station (FloraBase,
2008); however it does not appear within the 30 km search boundaries (but does when the
buffer is increased to 60 km).
These taxa were not recorded during the survey.
In Western Australia conservation significance is determined under the Wildlife Conservation
Rare Flora (DRF) is currently protected under the Western Australian Wildlife Conservation
considered likely to become extinct or rare. They are defined as “taxa which have been
adequately searched for and deemed to be either rare, in danger of extinction, or otherwise in
need of special protection in the wild”. These taxa are legally protected and removal or
impact to their surroundings cannot be conducted without ministerial approval obtained
specifically on each occasion for each population (for definitions of categories, see Appendix
Under the Wildlife Conservation Act 1950, the Minister for the Environment may declare
or otherwise in need of special protection.
Currently 143 DRF are known to occur in the Avon Wheatbelt Bioregion. Five DRF species
are known from the vicinity of the Koolanooka project area;
(syn. Halosarcia bulbosa).
No DRF taxa protected by this Act were recorded during the survey.
Currently, 11 DRF taxa are known to occur in the Yalgoo bioregion, and two DRF taxa,
vicinity of Blue Hills (Western Australian Herbarium, 2008).
at John Forrest Lookout.
Blue Hills. DEC also recorded collections at Blue Hills from their 2005 Tallering Peak
surveys (collected as Acacia sp. Blue Hill Range (R.J. Cranfield 8582)).
No DRF taxa protected by this Act were recorded during the current survey.
In addition to the Declared Rare Flora taxa, the Department of Environment and
Conservation (DEC) maintains a list of Priority Flora taxa, which may be rare or threatened
but for which there are insufficient survey data to accurately determine their status, or are
regarded as rare but not currently threatened. A priority flora taxon is assigned to one of four
priority categories – P1 to P4 in order of rarity and level of threat (Atkins, 2008, and defined
in Appendix C). Five hundred thirty three Priority taxa are currently listed as occurring in
the Avon Wheatbelt Bioregion and 89 in the Yalgoo Bioregion (FloraBase, 2008).
4.1.4 Conservation significant flora recorded previously within the
survey area or in adjacent areas
Six hundred and seventy seven Declared Rare and Priority Flora taxa are known to occur in
the Avon Wheatbelt Bioregion (Western Australian Herbarium, 2008) and a combination of
33 DRF and Priority Flora have been recorded in the vicinity of Koolanooka. Two DRF taxa
and four Priority flora taxa were recorded during a survey of Koolanooka Hills and of the
road and rail areas within the Midwest mining leases (ATA, 2004a): Eremophila viscida and
Trudgen 5368) (P2), Frankenia glomerata (P3), Grevillea stenostachya (P3) and Persoonia
recorded during earlier surveys in the area, but it is no longer listed. This previous survey
encompassed a much larger area including the plains to which Eremophila viscida and
Halosarcia bulbosa (DRF) are restricted.
The following seven Priority Flora were recorded during the DEC’s survey of Koolanooka
and Perenjori Hills; Melaleuca barlowii (P1), Millotia dimorpha (P1), Rhodanthe collina
(P1), Baeckea sp. Perenjori (J.W. Green 1516) (P2), Stenanthemum poicilum (P2),
Caruso, 2006). Table D.1 (Appendix D) lists previously recorded conservation significant