(GPS Datum AMG84 50J
Eremophila occidens (P2) ms
Scholtzia sp. Folly Hill (P2) 215401
Grevillea rogersoniana (P3) 212708
Macarthuria intricata (P3) 215400
Physopsis chrysophylla (P3) 212402
Jacksonia dendrospinosa (P4) 229965
^ - Data extracted from Trudgen and Keighery (1995) includes community groups 1,5
and 6 only
Eighteen plant communities were defined and mapped during the surveys in 2003 and 2004. These
community types consist of seven Eucalyptus Woodlands, ten Shrublands and one mosaic community.
The complete species list of each plant community is listed in Appendix B. A description of each plant
community is given below.
Low Open Woodland of Eucalyptus selachiana and Eucalyptus roycei with occasional emergent Banksia
Low Open Woodland of Eucalyptus selachiana and Eucalyptus fruticosa with occasional emergent
Low Open Woodland of Eucalyptus fruticosa and Eucalyptus obtusiflora subsp. obtusiflora over Acacia
Low Open Woodland of Eucalyptus selachiana and Eucalyptus ?eudesmioides over Acacia ramulosa var.
Low Open Woodland of Eucalyptus obtusiflora subsp. obtusiflora over Acacia ramulosa var. ramulosa
Low Open Woodland of Eucalyptus mannensis subsp. vespertina over Acacia ramulosa var. ramulosa
Low Open Woodland of Eucalyptus selachiana over Calothamnus formosus subsp. formosus and Acacia
Tall Shrubland of Calothamnus formosus subsp. formosus and Hakea stenophylla subsp. notialis with
Tall Open Shrubland of Calothamnus formosus subsp. formosus, Hakea stenophylla subsp. notialis and
sp. Nanga (pn) over Triodia danthonioides.
Low Open Shrubland of Acacia ligulata and Hakea stenophylla subsp. notialis with occasional emergent
Tall Open Shrubland of Grevillea gordoniana and Acacia ligulata with occasional emergent Eucalyptus
Low Open Shrubland of Acacia subrigida (P2) with occasional emergent Eucalyptus ?eudesmioides and
Low Open Shrubland of Acacia longispinea with occasional emergent Eucalyptus mannensis subsp.
Tall Open Shrubland of Acacia sclerosperma subsp. sclerosperma and Acacia ramulosa var. ramulosa
Tall Open Shrubland of Acacia xiphophylla, Acacia drepanophylla (P3) and Acacia ramulosa var.
Tall Open Shrubland of Acacia xiphophylla and Acacia drepanophylla (P3) over Acacia grasbyi, Acacia
Tall Open Shrubland of Physopsis chrysophylla (P3) and Acacia rostellifera over Calothamnus formosus
The pattern of plant communities differs significantly in the northern third of survey area compared to the
southern end as the shrublands and patches of Eucalypts in the north form a mosaic of locally changing
communities (often over 50 metres, which cannot be mapped at the scale as attached). This mosaic of
local communities has been combined into the M1 community.
Mosaic of patches of a Tall Open Shrubland of Acacia ramulosa var. ramulosa, Acacia ligulata and
subsp. vespertina and Eucalyptus obtusiflora subsp. obtusiflora over Eremophila maitlandii and
of Acacia ramulosa var. ramulosa and Acacia roycei over Melaleuca leiopyxis and Malleostemon
The intact vegetation structure and low density of introduced species suggests the vegetation within the
Amy Zone to be in “Excellent” condition, when applied to the condition scaling used in Bush Forever
publications (Department of Environmental Protection, 2000), as adapted from Keighery (1994). Despite
the presence of Brassica tounefortii in some disturbed areas, the scale considers vegetation to be in
“Excellent” condition when the total cover of introduced species is less than 20%. Soil structure and
understorey density are degraded due to grazing in Communities S7, S8 and S9 on the potential access
road corridors, which would result in a poorer condition scale of “Very Good” (Mattiske Consulting Pty
None of the plant communities within the survey area are considered Threatened Ecological Communities
pursuant to Schedule 2 of the Environmental Protection Biodiversity Conservation Act (1999) or
according to English and Blyth (1997).
Fourteen of the eighteen plant communities (E1, E2, E3, E4, E6, E7, S1, S2, S3, S4, S5, S6, S10 and M1)
Shark Bay (Beard, 1990). Community S5 is particularly significant, as it is restricted to deep valleys,
which are an unusual landform both locally and within the region.
Several plant communities within the survey area are considered locally significant where Priority species
S8, S9 and S10 are locally significant, as Priority species constitute a dominant element within the
communities. Based on current information the distribution of S10 appears to be restricted within the
survey area. The Communities E4 and S4 are also locally significant as they support populations of
CALM FloraBase, 2005). The plant Communities S7, S8 and S9 are also locally significant as they are
restricted to calcareous soils in the eastern part of the survey area, but they are unlikely to be markedly
influenced by the proposed development.
Three extensions of the original survey area were mapped during April and November 2004. The plant
composition from those communities in the central part of the Coburn survey area. In the additional
survey of the proposed southern haul road conducted in November 2004, the plant Communities S1, S2,
S7, S9, E2, E3, E4, E6 and E7 were recorded. These were floristically equivalent to the communities
recorded in previous surveys of the initial haul road to the north and the main survey area. Eastern
sections of the proposed haul road were difficult to access and therefore a thorough search for Eucalyptus
shrubland communities. There is evidence of recent fire(s) in Community S1 from burnt stumps, a
shallow layer of ash below the soil surface and the low and closed structure of the community. In
comparison, Communities S2 and S3 appear to have no evidence of recent fire(s) and typically have a
mature and open structure. The similar species composition but contrasting structure of these
communities, suggests that Community S1 may represent a younger successional stage of either
Community S2 or S3. In the absence of fire, local edaphic factors or other site differences will then
presumably determine if an S1 community will succeed into either S2 or S3. The latter patterns may also
assist in proposed rehabilitation programs as the passage of fire may assist in the re-establishment of
some species from litter and seed stock.
The proposed Coburn mineral sand mine is located south of Shark Bay. The survey area overlaps with a
part of the Southern Carnarvon Basin, which is a region that until recently was poorly known botanically
(Keighery et al. 2000). The region was first mapped by Beard (1976) and more recently, surveys have
been conducted in the Shark Bay World Heritage Property by Trudgen and Keighery (1995) and the
Southern Carnarvon Basin by Keighery et al. (2000) and Gibson et al. (2000). The broad composition and
pattern of the flora reflects the major floristic boundary that runs through the region, defining the
Southwestern and Eremaean Botanical Provinces (Beard 1976). This boundary represents the transition
from the diverse Kwongan and woodlands of southwestern Australia and the less diverse Acacia
shrublands of the Carnarvon Basin, which is imposed by major climatic and soil gradients across the area.
This major floristic boundary is a defining feature of the flora in the survey area and is reflected by the
diverse range and high endemism of the species and plant communities recorded in the present study.
The extensive shrubland and Eucalypt communities in the Amy Zone are a distinctive element of the
Heath” or heath with occasional trees. Importantly, Beard (1976) reported that this vegetation type is
endemic to the Shark Bay area. The distinctive feature of this vegetation is it contains Acacias that are
typical of the arid Eremaean region but also contains elements of the diverse Kwongan and woodlands of
southwestern Australia, including members of the Proteaceae and the Myrtaceae. Beard (1976) first
determined this vegetation to have affinities with the Southwestern Botanical Province, but floristic,
climatic and edaphic evidence from Gibson et al. (2000) currently suggests a closer affinity to the
Eremaean Botanical Province. This regionally significant vegetation structure encompasses the
Communities E1, E2, E3, E4, E6, E7, S1, S2, S3, S4, S5, S6, S10 and M1 that were mapped in the
present study. Of these communities, on the basis of aerial photograph interpretations, the dominant
communities of S1, S2 and S3 appear to be extensive and occur well beyond the boundaries of the survey
area into the World Heritage area. Many of the Eucalypt (E prefix in community codes) communities
extend beyond the survey area. The actual extent of the different shrub and Eucalypt communities
beyond the survey boundaries should be clearer after the additional work proposed for the coming
A number of communities with significant local conservation values were defined in the current study.
Communities S5, S8, S9 and S10 are of particular local significance, as priority species constitute a
dominant element of the species composition. The Communities S2 and S3 are also significant as they
have a mature, open structure, which is important for the establishment of the late successional Priority
species (Jacksonia dendrospinosa (P4) and Scholtzia sp. Folly Hill (P2)), and may also be important for
maintaining high reptile diversity (as found in S3, Ninox Wildlife Consulting 2004)). There is also a high
diversity of vertebrate fauna in the northern section of the survey area, which may be associated with the
diverse mosaic (M1) communities (Ninox Wildlife Consulting 2004).
survey area was reflected in the biogeographical pattern of the species in the present study. Many species
recorded are commonly found in the Southwestern Botanical District and are at the northern limit of their
distribution, while other species common in the Eremaean Botanical District are at the southern or eastern
limit of their distribution. There are also 13 taxa that are restricted to the intermediate zone between the
two districts and are endemic to Shark Bay.
The significance of the nine Priority Flora species recorded in the survey area was reviewed in relation to
mining operations pose the greatest threat to Eremophila occidens (ms) (P2) as it is locally common in
the survey area but its distribution beyond the area is highly restricted (only four collections from two
isolated areas). Secondly, Acacia subrigida (P2) may need further taxonomic revision as some of the
populations recorded previously from Shark Bay have different leaf morphology. Acacia drepanophylla
(P3), Grevillea rogersoniana (P3) and Macarthuria intricata (P3) are significant, as they are endemic to
Shark Bay. Finally, the presence of Grevillea stenostachya (P3) in the survey area represents a significant
range extension from other known populations. It is important to note that the distribution of the Priority
flora in the survey area is likely to be more extensive than current maps indicate, which are based on a
limited number of site recordings. Additionally, the area surrounding Shark Bay is a centre of Acacia
species diversity and hybridisation, and there are many species complexes in the area that may include
taxa that are currently undescribed (B. Maslin, pers. comm.). Therefore, other species that may have
specific conservation significance could also occur in the area.
A total of 231 taxa (including subspecies and varieties) from 131 genera and 51 families were recorded in
the Coburn survey area (Appendix A). A similar composition of species was collected in the present
study with the exception of the priority species listed in Table 4. Trudgen and Keighery (1995) recorded
528 taxa over a larger area, which included Nanga Station, Western Hamelin station, Tamala Station,
Coburn Station, Zuytdorp National Park, Cooloomia Nature Reserve and associated crown land
(Appendix A). The authors also recorded a range of Rare and Priority Flora that were not recorded in the
survey area (Table 4). The distribution of the majority of these species lie outside the survey area, while
others may not have been detected in the present study due to low rainfall or they occur at extremely low