Aug & Sept 2009
Sept 2009 & March
The families represented by the greatest number of taxa in the combined species list were the
Fabaceae (151 taxa), Myrtaceae (125 taxa), Asteraceae (63 taxa), Poaceae (61 taxa) and
Scrophulariaceae (58 taxa). Genera represented by the greatest number of taxa were Acacia (87
taxa), Eremophila (56 taxa), Grevillea (32 taxa), Eucalyptus (25 taxa) and Melaleuca (21 taxa).
OPR Rail Proposal – Vegetation and Flora Assessment
The families and genera represented by the greatest number of taxa and the most frequently
are listed in Table 5.3.
Species richness is often affected by the location of the quadrat in the landscape. Freehold quadrats
with high species richness were in areas associated with mesa slopes and floodplains, while those
areas having low species richness in the Freehold were degraded low hilltops, creeklines and salt
depressions. Pastoral quadrats with high species richness were recorded in areas associated with
higher water availability, such as drainage lines and floodplains. Pastoral quadrats with low species
diversity were associated with exposed areas such as flat plains, hardpans and salt pans.
Quadrats having the highest and lowest species richness in the Pastoral and Freehold sections are
listed in Table 5.4.
Quadrats with the Highest and Lowest Species Richness
Highest Species Richness
Lowest Species Richness
Average Species Richness
E066 (55 species)
E063 (48 species)
E067 (44 species)
E110 (39 species)
E092 and E054 (34 species each)
E099 (6 species)
E009, E059 and E122 (7 species
E049 and E080 (8 species each)
A122 (37 species)
A140 (29 species)
C175 and C112 (28 species each)
A033 and B074 (27 species each)
C145 and A020 (26 species each)
B089 (3 species)
A057, B088, B035, B017, B001,
C133, D004 and D011 (4 species
A049, D149 (5 species each)
Species accumulation curves (SAC) provide a theoretical basis for understanding the relationship
between sampling effort and the accumulation of species, and therefore provide a means of
estimating survey adequacy. As sampling effort increases with a corresponding increase in survey
area and time, the rate at which new species are recorded is reduced and the number of species
recorded levels out (i.e. becomes asymptotic). At this point, where there is a diminishing return with
regards to increase in species richness with sampling effort, the survey size is deemed sufficient.
Sampling Adequacy for the Freehold Land Area
Flora sampling adequacy was estimated using SAC analysis (Colwell, 2006) (Figure 5.1) and
extrapolation of the curve to the asymptote using Michaelis‐Menten modelling. Using this analysis,
the incidence‐based coverage estimator of species richness (ICE Mean, Chao 2 Mean) was
determined as 580. As 450 taxa were recorded from the Freehold quadrats surveyed, this suggests
that approximately 77% of the flora species potentially present within the Freehold section of the
Study Area were recorded during the survey.
However, the data used for these calculations includes only those species recorded in the quadrats
surveyed in the Freehold section; they do not include any opportunistic collections made in this
section. When the additional 191 taxa collected opportunistically during the Freehold quadrat and
transect surveys are added to the total, 641 taxa were recorded. This total suggests that
approximately 110% of the flora species potentially present within the Freehold section of the Study
Area were recorded during the survey.
Sampling Adequacy for the Pastoral Land Area
Flora sampling adequacy was estimated using SAC analysis (Colwell, 2006) (Figure 5.2) and
determined as 528. As 429 taxa were recorded from the Pastoral quadrats surveyed, this suggests
that approximately 81% of the flora species potentially present within the Pastoral section were
recorded during the survey.
surveyed in the Pastoral section of the Study Area; they do not include any opportunistic collections
made in this section. When the 91 additional taxa collected opportunistically during the Pastoral
quadrat and transect surveys are added to the total, 520 taxa were recorded. This total suggests that
approximately 98% of the flora species potentially present within the Pastoral land area of the Study
Area were recorded during the survey.
FLORA OF CONSERVATION SIGNIFICANCE
Environment Protection and Biodiversity Conservation Act 1999
Flora species are protected at a National level under the Commonwealth EPBC Act. The EPBC Act
contains a list of species that are considered either ‘Critically Endangered’, ‘Endangered’,
‘Vulnerable’, ‘Conservation Dependent’, ‘Extinct’ or ‘Extinct in the Wild’ (for category definitions
refer to Table K.1, Appendix K).
The database searches show that 10 species protected by this Act potentially occur in the vicinity of
the Study Area. These species and their EPBC Act categories are listed in Table 5.5. Their likelihood
of occurrence and preferred habitat type are listed in Table 5.6.
Confirmed by current survey
and DEC records
Confirmed by DEC records
Confirmed by DEC records
Caladenia bryceana subsp. cracens
Confirmed by current survey
and DEC records
Two species listed under the EPBC Act were recorded during the ecologia survey: Caladenia
known distributions of these taxa are provided below.
0.3 m high. The flowers of this spider orchid are produced from August to October and are green,
yellow and red. Long, fine hairs grow along the bracts, leaves and stems. Caladenia hoffmanii is
generally found growing on clay‐loam soils, laterite and granite rocky outcrops, ridges, swamps and
gullies (WAHERB, January 2010).
Fifteen plants of Caladenia hoffmanii was recorded at two locations (separated 50 m apart) in the
Freehold section of the Study Area. The coordinates for the sites at which this DRF was recorded are
and listed in Table G.1 and have been mapped on Figure G.1 (Appendix G).
The conservation significance of this taxon is provided in Section 0.
(Photography by A.P.Brown, S.D. Hopper & S.J. Patrick. Image used with the permission of the Western Australian Herbarium, Department
of Environment and Conservation (http://florabase.dec.wa.gov.au/help/copyright). Accessed on Wednesday, 2 December 2009).
Eucalyptus blaxellii (MYRTACEAE) ‐ Vulnerable
characterised by having buds with fully inflexed stamens, geniculate (strongly elbowed) staminal
filaments and a style that tapers basally. The leaves are sparsely reticulate, and the adult leaves are
glossy green. The fruit is small and obconical in shape. One of the four species within this series is
the very common Eucalyptus loxophleba. Eucalyptus blaxellii is distinguished from E. loxophleba by
smooth bark and a mallee growth habit (Johnson & Hill, 1992).
Four‐hundred and thirty‐three plants of Eucalyptus blaxellii was recorded at 44 locations (separated
50 m apart) in the Freehold section of the Study Area. The coordinates for the sites at which this
vulnerable, Priority 4 taxon was recorded are listed in Table G.1 and have been mapped on Figure G.1
An additional two species listed under the EPBC Act were recorded by the DEC database searches:
characteristics and known distributions of these taxa are provided below.
white, pink, occurring from August to October. Philotheca wonganensis is commonly found in red
Twelve plants of Philotheca wonganensis has been recorded at two locations (separated 50 m apart)
in the Freehold section of the Study Area by the DEC searches.
Photography by K. Bettink & K. Dixon. Image used with the permission of the Western Australian Herbarium, Department of Environment
and Conservation (http://florabase.dec.wa.gov.au/help/copyright). Accessed on Monday, 17 May 2010.
Drummondita ericoides (RUTACEAE) – Endangered
Drummondita ericoides (Plate 5.4) is a divaricately branched shrub, growing to 0.3 – 1 m in height.
The flowers are yellow, white, violet to purple, and occur from September to October. Drummondita
Ten plants of Drummondita ericoides has been recorded at four locations (separated 50 m apart) in
the Freehold section of the Study Area by the DEC searches.
Photography by S.D. Hopper & S.F. Patrick. Image used with the permission of the Western Australian Herbarium, Department of
Environment and Conservation (http://florabase.dec.wa.gov.au/help/copyright). Accessed on Monday, 17 May 2010.
Conservation significance in Western Australia is determined under the WC Act. Currently, DRF
species are protected under the Western Australian Wildlife Conservation (Rare Flora) Notice 2008(2)
of the WC Act. This notice lists flora taxa that are extant and 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 their removal or impact to their surroundings cannot be conducted without
Ministerial approval, obtained specifically on each occasion for each population (refer to Table K.2
(Appendix K) for category definitions).
A search of the DEC’s DRF database indicated that 12 DRF taxa have been recorded within a 2 km
buffer of the Study Area. These species and their preferred habitats are listed in Table 5.6, along
with a comment on the probability of each species being located within the Study Area based on
DRF Taxa Protected by the WC Act Recorded Within a 2 km Buffer of the Study Area
Occurrence in the
Sand over limestone, in low heath on
limestone hills, or on winter‐moist
Clay, loam, laterite and granite. Rocky
outcrops and hillsides, ridges, swamps
Sandstone outcrops, top edges of
Sandy clay or loam plains.
Rocky coastline areas
Confirmed by DEC
Granitic soils, sandy loam. Stony
Lateritic and granitic soils. Yellow and
Gravelly clay over limestone
Gravelly soil, sand, loam, or clay;
Red sandy soils
Schoenia filifolia subsp. subulifolia
Pale yellow‐grey‐brown clay. Swampy
flats, tops of breakaways, crabholes.
Clay, loam. River banks, seasonally‐
Currently, 73 DRF taxa are listed as occurring in the Geraldton Sandplains region, 11 in the Yalgoo
region and 1 in the Murchison region (WAHERB, April, 2010).
One DRF taxon; Caladenia hoffmanii was recorded in the Study Area during the current survey and is
protected by the WC Act. An additional two DRF taxa; Drummondita ericoides and Philotheca
The DEC maintains a list of Priority Flora taxa, which are considered poorly known, uncommon or
under threat but for which there is insufficient justification, based on known distribution and
population sizes, for inclusion on the DRF schedule. A Priority Flora taxon is assigned to one of four
priority categories (Atkins (2), 2008) as defined in Table K.3, Appendix K.
Currently, 507 Priority Flora taxa are listed as occurring in the Geraldton Sandplains regions, 97 in the
Yalgoo region and 150 in the Murchison region (WAHERB, April, 2010).