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OPR Rail Development – Vegetation and Flora Assessment
May 2010
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In 2005, the DEC surveyed Banded Ironstone Formations (BIF) of the Yilgarn Craton, including areas in
the Murchison and Yalgoo bioregions:
•
Flora and vegetation communities were surveyed in the central Tallering Land System of the
Yalgoo bioregion (south of Yalgoo) (Markey & Dillon, 2008a). One hundred and three quadrats
were established during the survey and one DRF taxon and 13 Priority Flora taxa were
recorded (Table B.1, Appendix B).
•
Markey & Dillon (2008b) surveyed the flora and vegetation at Weld Range (Murchison
bioregion). Fifty‐two quadrats were established during the survey and six main vegetation
communities (and four sub‐communities) were described. Eight Priority Flora taxa were
recorded (Table B.1, Appendix B).
•
The flora and vegetation of the Jack Hills (Murchison bioregion) were surveyed by Meissner &
Caruso (2008). Fifty quadrats were established during the survey and six vegetation
communities were described. Four Priority Flora taxa were recorded (Table B.1, Appendix B).
ecologia (2009a, in preparation) conducted an extensive three phase vegetation and flora
assessment at Weld Range; surveys were completed in 2006, 2007 and 2008. A total of 239 quadrats
were established during the surveys and seven vegetation communities (and 16 sub‐communities)
were described and mapped. Twenty‐four Priority Flora species were recorded (Table B.1, Appendix
B).
During 2004/2005, Mattiske (2005) conducted a flora and vegetation assessment at Jack Hills. One
hundred and twenty‐two quadrats were established during the survey and 18 vegetation
communities were described and mapped. Four Priority Flora taxa were recorded (Table B.1,
Appendix B).
ecologia (2009b, Draft) also conducted a two phase vegetation and flora assessment at Jack Hills in
2006/2007. One‐hundred and ninety‐five quadrats were established during the survey and six
vegetation communities (and 18 sub‐communities) were described. Seven Priority Flora taxa were
recorded (Table B.1, Appendix B).
A baseline vegetation survey was conducted near Mount Magnet in 1994 by Landcare Services
(1995). Quadrats were assessed at eight sites in native vegetation and one rehabilitated waste dump
site. The dominant vegetation of the area was Acacia aneura woodlands with a mixed understorey
of chenopods and Eremophila species. Of the 206 endemic taxa recorded during the survey, three
were Priority Flora: Alyxia tetanifolia (Priority 3), Calytrix erosipetala (Priority 3) and Grevillea
inconspicua (Priority 4).
Alan Tingay & Associates (1998) completed an environmental appraisal and management plan for a
proposed railway from Tallering Peak to Oakajee. They reported on findings from several vegetation
and flora surveys conducted along the route. Eleven vegetation associations were described and 321
flora taxa were recorded. Twelve Priority Flora taxa were recorded along the route: Scholtzia sp.
Gunyidi (J.D. Briggs 1721) (Priority 2), Scholtzia sp. Murchison River (A.S. George 7098) (Priority 2),
Thryptomene sp. East Yuna (J.W. Green 4639) (Priority 2), Thryptomene stenophylla (Priority 2),
Thryptomene sp. Yuna Reserve (AC Burns 100) (Priority 2), Acacia leptospermoides subsp.
psammophila (Priority 3), Baeckea sp. Walkaway (A.S. George 11249) (Priority 3), Geleznowia
verrucosa (Priority 3), Grevillea candicans (Priority 3), Microcorys tenuifolia (Priority 3), Persoonia
pentasticha (Priority 3), and Verticordia capillaris (Priority 4).
In 1998, Landcare Services Pty Ltd (1998) conducted a flora and fauna survey from Oakajee to south
of Geraldton. Ten vegetation types were described and a total of 117 flora taxa were recorded. Two
Priority Flora species were recorded: Grevillea erinacea (Priority 3) and Stenanthemum divaricatum
(Priority 3).
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OPR Rail Development – Vegetation and Flora Assessment
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Dames & Moore (1993) conducted a flora and fauna assessment at Oakajee in 1993. Six vegetation
types associated with six distinct terrain types were described and mapped at a scale of 1:25,000.
Heaths and shrublands dominated the vegetation, with some minor woodland in river valleys. One
hundred and sixty‐five flora taxa were recorded during the survey, including one Priority Flora
species ‐ Grevillea triloba (Priority 3).
In August 1997 Muir Environmental (1977) conducted a follow‐up survey of the area surveyed by
Dames and Moore (1993), as it was extended to include a buffer zone and quarry sites. The
vegetation of the six terrain types identified by Dames and Moore (1993) was re‐assessed. Two‐
hundred and seventeen taxa were recorded (52 more than in 1993). One confirmed DRF and two
Priority Flora taxa were recorded during this survey: Eucalyptus blaxellii (Vulnerable, Priority 4),
Grevillea triloba (Priority 3), and Verticordia penicillaris (Priority 4). The collection of a hybrid
specimen (a cross between Caladenia hoffmanii (DRF) and Caladenia longicauda) indicates that
Caladenia hoffmanii may have been present in the area.
ecologia (2009c in preparation) completed a single phase vegetation and flora survey (in 2006)
followed by a threatened flora survey (in 2009) at Oakajee. Twenty‐one quadrats were assessed
during the vegetation and flora survey, and 14 vegetation units were described and mapped at a
scale of 1:40,000. One DRF and 10 Priority Flora were recorded during the surveys (Table B.1,
Appendix B).
A biological survey of the Buller River area was conducted by ecologia (2009d, in preparation) in
2009. Five vegetation units at the sub association level were described and mapped. Sixty‐three
flora taxa were recorded, and none of these were DRF or Priority Flora.
An ecological survey was conducted by GHD (2009) for a proposed haul road between Jack Hills and
Weld Range. Twenty‐five quadrats were assessed during the vegetation and flora survey, and 18
vegetation units were described and mapped. Eight Priority Flora taxa were recorded during this
survey (Table B.1, Appendix B).
2.8.1
Vegetation Described by Beard
The Study Area lies predominantly in Beard’s (1976) Murchison region of the Eremaean Botanical
Province. The Murchison region is well known for the dominance of mulga (Acacia aneura)
woodlands, and the extensive flats and plains provide optimum conditions for these woodlands. On
the more favourable soils (plains and valleys) Acacia aneura generally grows in the form of a tree
with a single erect trunk and forms low woodlands. On less favourable soils (hill slopes and ridges) it
takes the form of a shrub producing shrublands/scrublands (Beard, 1976).
Most of the Study Area lies in the Upper Murchison subregion in the Murchison region of the
Eremaean Botanical Province (Beard, 1976). The vegetation of this area is described as:
•
Plains covered by continuous or interrupted Acacia aneura (mulga) low woodlands. Tree
deterioration and death is common in this area, and there is very little regeneration of the A.
aneura. This has resulted in large areas where only Senna and Eremophila species are present
or other Acacia species such as A. victoriae and A. tetragonophylla.
•
Granite and gneiss hills are generally covered with Acacia aneura (shrub form), and A.
quadrimarginea and A. ramulosa var. ramulosa or A. ramulosa var. linophylla. Understorey
species include Eremophila spathulata and Ptilotus obovatus. The main species at Jack Hills is
A. grasbyi (often a tree form) with Eremophila fraseri. Acacia aneura, A. ramulosa var.
ramulosa and Acacia tetragonophylla also occur. At Weld Range banded ironstone ridges
support two main species – Acacia aneura and Acacia quadrimarginea – additional species
include Eremophila latrobei, Scaevola spinescens and Ptilotus obovatus. The lower slopes are
covered with Acacia aneura and A. ramulosa var. linophylla.
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•
Sandplain patches consist of Acacia ramulosa var. linophylla scrub, with A. aneura less
commonly. While Eremophila leucophylla, Solanum lasiophyllum and Maireana convexa occur
as understorey shrubs.
•
Extensive salt flats, along the upper courses of the Murchison, are covered with Atriplex
vesicaria and Frankenia pauciflora, often with scattered Acacia sclerosperma and A. victoriae.
Downstream of the Murchison, the main vegetation is Acacia species scrub (A. victoriae, A.
sclerosperma and A. tetragonophylla) with scattered Eucalyptus camaldulensis.
A section of the Study Area is situated in the Yalgoo subregion in the Murchison region of the
Eremaean Botanical Province (Beard, 1976). The vegetation associated with this transitional area,
between the Eremaean Botanical Province and the South‐western Botanical Province, is described as:
•
Still Eremaean in character, but with the increase in rainfall and the shift of climate from
desert (arid) to Mediterranean, Acacia aneura decreases and is replaced by other Acacia
species. The vegetation also becomes lower and denser in a south‐westerly direction.
•
The plains of the inland portion of this subregion support mixed Acacia species scrub mainly of
A. ramulosa var. ramulosa, A. grasbyi, A. acuminata and A. tetragonophylla, with scattered A.
aneura. The stony hills are dominated by Acacia ramulosa var. ramulosa and A. acuminata
scrub, with A. quadrimarginea and A. stereophylla. The sandplains have a rich flora and are
dominated by Acacia ramulosa var. ramulosa and A. murrayana. Low‐lying plains support
Acacia sclerosperma and A. eremaea scrub, with Atriplex and Maireana species.
•
The south‐western portion of the subregion includes thickets of Acacia ramulosa var.
ramulosa, A. acuminata and Melaleuca uncinata occurring in midslope positions, while Acacia
ramulosa var. ramulosa scrub with scattered Callitris and Eucalyptus species occur in the
valleys.
A small section of the Study Area incorporates the Talisker vegetation system of the Eremaean
Botanical Province. The vegetation of this system is described by Beard & Burns (1976) as:
•
Sandplain associated with Acacia ramulosa var. ramulosa/Acacia ramulosa var. linophylla
scrub with scattered Eucalyptus species and Callitris columellaris. Understorey species include
Baeckea pentagonantha, Eremophila clarkei and Grevillea stenostachya.
The remaining section lies in the Greenough region of the South‐western Botanical Province,
incorporating the Yuna, Kalbarri, Northampton, Greenough and Mullewa vegetation systems (Beard,
1976; Beard & Burns, 1976). The vegetation of these systems is described as:
•
Yuna System: the yellow sandplains support scrub heath associations; Acacia‐Casuarina
species thickets occur on red sandplains; while scrub with mallee and scattered trees occur in
red soil depressions. Eucalyptus loxophleba and E. loxophleba‐E. salmonophloia woodlands
occur in bottomland soils west of Mullewa. The Greenough River valley is generally covered
with Acacia acuminata scrub and scattered Eucalyptus loxophleba. Salt flat vegetation is
primarily Tecticornia species and other samphires, with some Atriplex vesicaria and Melaleuca
thyoides.
•
Kalbarri System: the hills support Acacia‐Melaleuca species thickets with Acacia ligulata,
Melaleuca eleuterostachya and M. uncinata. Sandplains support a rich scrub heath which
covers most of the area ‐ Acacia rostellifera occurs near the coast, Adenanthos cygnorum,
Banksia attenuata and B. menziesii inhabit white sands, while Actinostrobus species, Banksia
prionotes, B. sceptrum and Xylomelum species occur in yellow sands. Small patches of mallees
include Eucalyptus loxophleba, E. eudesmioides and E. dongarraensis.
•
Northampton System: scrub heath associations occur on mesa tops (laterite and sand); laterite
species include Gastrolobium oxylobioides, Casuarina campestris, Xanthorrhoea preissii,
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OPR Rail Development – Vegetation and Flora Assessment
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Dryandra spp., Calothamnus spp., Hakea spp. and Melaleuca spp.; while the sand community
grows taller and more open with Acacia rostellifera, Banksia, Dryandra, Casuarina and
Gastrolobium species. Melaleuca‐Hakea spp. thickets occur on the Jurassic sediments
(generally forming steep scarp slopes) and the two dominant communities are Melaleuca
megacephala and Hakea pycnoneura and Casuarina campestris and M. uncinata. Acacia
acuminata scrub with Hakea species and scattered Eucalyptus loxophleba occur on the lower
undulating terrain on granites and granulites, while Allocasuarina campestris thickets occur on
gravelly soils and scattered Eucalyptus camaldulensis along drainage lines.
•
Greenough System: the rocky ridges support Acacia rostellifera and Melaleuca cardiophylla
thickets. Acacia‐Banksia species scrub (dominated by Acacia rostellifera and Banksia
prionotes) occurs on sand‐covered limestone. Acacia rostellifera low forests occur on the
alluvial flats, recent dunes commonly support Acacia ligulata open scrub, while Eucalyptus
camaldulensis and Casuarina obesa occur along creeklines.
•
Mullewa System: the sandplains support Acacia‐Casuarina‐Melaleuca thickets, whilst the
vegetation of the dissected terrain is Acacia acuminata scrub with scattered Eucalyptus
loxophleba and Casuarina huegeliana. Associated species include Acacia tetragonophylla and
Hakea preissii, with Senna and Eremophila species forming the lower shrub layer and
ephemerals comprising the ground layer.
The vegetation of the Study Area was mapped as 28 communities by Beard (1976) and Beard & Burns
(1976). These 28 units are described in Table 2.8 and shown in Figure 2.12 to Figure 2.16.
Oakajee Port and Rail
OPR Rail Development – Vegetation and Flora Assessment
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Table 2.8
–
Beard Vegetation Communities of the Study Area
Beard Code
Map
Unit
Vegetation Community
a1,14Si
Acacia aneura and Acacia quadrimarginea scrub.
a1,8Sr k1,2Ci
Acacia aneura and Acacia sclerosperma with Atriplex and Maireana spp. succulent
steppe.
a1,9Li
Acacia aneura, Acacia ramulosa var. ramulosa and Acacia ramulosa var. linophylla low
woodland.
a10,11Si k1,2Ci
Acacia victoriae, Acacia xiphophylla and Acacia eremaea with Atriplex and Maireana
spp. succulent steppe.
a14Si
Acacia quadrimarginea scrub.
a1Li
Acacia aneura low woodland.
a1Li a9,17Si
Acacia aneura low woodland with understorey of Acacia ramulosa var. ramulosa,
Acacia ramulosa var. linophylla and Acacia grasbyi.
a1Lp
Acacia aneura, trees in groves or patches.
a1Si
Acacia aneura scrub.
a33Sc
Acacia rostellifera thicket.
a8,9Sr k1,2Ci
Acacia sclerosperma, Acacia ramulosa var. ramulosa and Acacia ramulosa var.
linophylla with Atriplex and Maireana spp. succulent steppe.
a8Sr k1,2Ci
Acacia sclerosperma with Atriplex and Maireana spp. succulent steppe.
a9,19Si
Acacia ramulosa var. ramulosa, Acacia ramulosa var. linophylla and Acacia acuminata
scrub.
a9,20Si
Acacia ramulosa var. ramulosa, Acacia ramulosa var. linophylla and Acacia murrayana
scrub.
a9Si
Acacia ramulosa var. ramulosa and Acacia ramulosa var. linophylla scrub.
acSc
Acacia ‐ Casuarina spp. thicket.
anSi
Mixed Acacia spp. scrub.
ceLr a9Si
Acacia ramulosa var. ramulosa and Acacia ramulosa var. linophylla scrub with Callitris
columellaris and Eucalyptus spp.
e6c5Mr a9,19Si
Acacia ramulosa var. ramulosa, Acacia ramulosa var. linophylla and Acacia acuminata
scrub with scattered Eucalyptus loxophleba and Casuarina huegeliana.
e6,8Mi
Eucalyptus loxophleba and Eucalyptus salmonophloia sclerophyll woodland.
e6Mr a19Si
Acacia acuminata scrub with scattered Eucalyptus loxophleba.
e6Mr eaSi
Eucalyptus spp. (mallee) and Acacia spp. scrub with scattered Eucalyptus loxophleba.
k1,3Ci
Atriplex spp., Tecticornia spp. and other samphires succulent steppe.
k3Ci
Tecticornia spp. and other samphires succulent steppe.
mhSc
Melaleuca ‐ Hakea spp. thicket.
x2SZc
Scrub heath coastal association.
x3SZc
Scrub heath inland association.
x3SZc/acSc
Acacia ‐ Casuarina spp. thicket with scrub heath inland association.
Note:
‘Beard Code’ column refers to vegetation types mapped by Beard (1976) and Beard & Burns (1976).
3
2
1
4
200000
300000
400000
500000
600000
6700
000
6800
000
6900
000
7000
000
7100
000
7200
000
K
0
30
60
Kilometres
1:1,500,000
Absolute Scale -
Legend
Proposed Rail Alignment
Proposed Project Area
Coordinate System
Name: GDA 1994 MGA Zone 50
Projection: Transverse Mercator
Datum: GDA 1994
Figure:
2.12
Project ID: 1131
Drawn: AH
Date: 10/07/09
Beard Vegetation of the
Study Area
(Overview)
A3
Unique Map ID: A014
x2SZc
anSi
e6Mr a19Si
x3SZc
k3Ci
e6Mr eaSi
mhSc
e6c5Mr a9,19Si
acSc
x3SZc/acSc
acmSc
x4SZc
ceLr a9Si
abSi
a9,19m6Sc
e6Mr a19Si/c3Sc
a9,20Si
e6,8Mi
a33Sc
a9,19Si
k1,3Ci
a14Si
e6Mr a9,19Si
e6,22Mr eaSi
mSi k3Ci
a21Sr
ds
a8Sr k1,2Ci
e6Mi
a23Lc
275000
300000
325000
350000
375000
6825
000
6850
000
6875
000
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