OPR Rail Development – Vegetation and Flora Assessment
River drainage systems
Low gentle to moderate
Tall shrubs of Grevillea – Melaleuca ‐ Acacia spp. over species‐rich open
Source: ecologia, 2009c in preparation.
GHD (2009) surveyed the vegetation and flora of a proposed haul route between Jack Hills and Weld
Range. Twenty‐five quadrats were established during the survey and 18 vegetation communities
were described (Table 2.14).
Table 2.14 – Vegetation Communities Recorded Between Jack Hills and Weld Range
Philotheca aff. tubiflora over very open grassland of Eragrostis sp.
Tall open shrubland of Acacia tetragonophylla and Acacia xanthocarpa to 2.5m over low shrubland of
1.6 m over very hard open grassland of Cymbopogon ambiguous.
Tall open shrubland of Acacia demissa and Acacia grasbyi over low open shrubland of Ptilotus obovatus
m over tall open shrubland of Eremophila platycalyx subsp. platycalyx to 2.2 m over low open shrubland
of Senna spp. to 1.2 m over very open grassland of Themeda triandra to 0.7 m.
open shrubland of Eremophila forrestii to 1.3 m over very open grassland of Eriachne helmsii.
Low open closed forest of Acacia aneura var. 1 and Acacia craspedocarpa x aneura to 6.5 m over tall
shrubland of Acacia kempeana, Acacia ramulosa var. linophylla and Acacia cuthbertsonii subsp.
herbland of Boerhavia coccinea and/or open grassland of Eriachne benthamii to 1 m.
Low open woodland of Acacia aneura var. 1 to 5m over low open shrubland of Ptilotus obovatus, Senna
grassland of Aristida contorta, Eriachne aristidea, Eriachne helmsii and Monachather paradoxus to 1m.
Tall open shrubland of Acacia tetragonophylla and Acacia synchronicia to 3 m over tall shrubland of
shrubland of Senna artemisioides subsp. oligophylla and Senna glutinosa subsp. x luerssenii to 1.5 m with
a very open grassland of Aristida contorta, Eragrostis eriopoda and Eriachne aristidea to 0.45 m.
of Eremophila latrobei x margarethae to 1.4 m over grassland of Aristida holathera var. holathera and
and Acacia ramulosa var. ramulosa to 3.2 m over low open shrubland of Eremophila forrestii, Eremophila
over very open grassland of Aristida contorta, Aristida holathera var. holathera, Monachather paradoxus
and Eragrostis eriopoda to 0.4 m.
open grassland of Eragrostis eriopoda
Open scrub of Acacia aneura var. argentea, Acacia craspedocarpa, Acacia tetragonophylla and Grevillea
shrubland of Eremophila glutinosa, Eremophila spathulata, Senna sp. Meekatharra, Acacia xanthocarpa,
m over tall shrubland of Eremophila macmillaniana to 2.5 m over low open shrubland of Eremophila
Meekatharra, Eremophila forrestii and Ptilotus obovatus to 1.5 m over very open grassland of Aristida
open herbland of Sida sp. Golden Calyces Glabrous and Goodenia berardiana to 0.3 m over very open
grassland of Eriachne mucronata to 0.35 m
low open shrubland of Aluta aspera subsp. hesperia to 0.4 m over very open grassland of Aristida
Source: GHD, 2009.
The survey methods adopted by ecologia were formulated using:
The Western Australian EPA’s position paper on terrestrial biological surveys as an element of
assessment (EPA, 2004).
Consultation with the DEC and other relevant government officers.
survey combined the following methodological approaches:
Background research: to gather background information on the footprint or target area (i.e.
characterise the flora and range of vegetation units present in the Study Area and to identify
scale and its local context or significance (if the broader scale is well known).
Prior to conducting the surveys, a review was undertaken of factors likely to influence survey design
using EPA Guidance Statement No. 51. These factors and the methodological actions taken in
response are presented in Table 3.1.
Sampling Design and
Intensity at Two Levels –
Regional and Area Specific
Statement No. 51
Quadrats were distributed across the Study Area at approximately 1 per linear kilometre. More quadrats were chosen in the areas with
higher diversity. This level of survey was adequate to record most of the vegetation communities at an area specific level in the Study
Area. Survey methodology is described in section 3 and the survey limitations and constraints are described in Table 6.1. Regional data
was available from a number of sources as described in section 2.8.
Landform – Scale, Rarity,
Aerial photographs and land system maps were used to select quadrat locations. This ensured that any different landforms or land
systems that could potentially contain different or unique vegetation communities were visited during the survey. In addition, the
botanists undertaking the survey ground‐truthed the vegetation associations occurring in the sites chosen from the aerial photographs,
and added or removed sites depending on the landforms encountered while traversing the Study Area. Multiple sites were assessed on
each landform and the survey methodology is described in section 3.
Habitat – Scale, Rarity,
Statement No. 51
Aerial photographs were used to select quadrat locations. This ensured that all habitats displaying potentially different or unique
vegetation communities were visited during the survey. In addition, the botanists undertaking the survey ground‐truthed the vegetation
communities occurring in the sites chosen from the aerial photographs, and added or removed sites depending on the habitats
encountered while traversing the Study Area. Multiple sites were assessed in each habitat and the survey methodology is described in
Diversity and Seasonality
Statistical analysis was carried out on data collected from 614 quadrats (605 quadrats assessed during the survey of the Study Area and 9
quadrats assessed by ecologia, 2009a for Weld Range). Following analysis, the structure of the vegetation communities in the Study Area
have been described (Appendix H) and the main communities were mapped (Appendix I).
The vegetation communities were surveyed in one phase. Any unknown or annual species encountered during the threatened flora
survey were collected, providing a second phase collection of the flora in the Study Area.
Potential for Conservation
Significant Flora to occur,
Based on Habitat Analysis
Using the species from the relevant government database searches and the results of other biological surveys in the region, and using the
habitat requirements for each of these species, a likelihood of occurrence in the Study Area has been determined and is shown in
Appendix C. Land systems likely to provide habitat for conservation significant flora were targeted during the threatened flora transect
Species and Ecosystem
diversity and Heterogeneity
Species accumulation curves are included in section 5.2. Details on the flora of the Study Area are included in section 5.1. Detailed
vegetation descriptions, including the area covered by each vegetation community in the Study Area are provided in Appendix H.
Vegetation community maps are provided in Appendix I.
Information on Adjacent
Areas – Previous Surveys
and Herbarium Records
Information was requested from the relevant government databases and was collated from reports available from other vegetation and
flora surveys undertaken in the vicinity of the Study Area. The results from these searches and surveys are provided in Section 2.8.
Before the first field survey, searches of various government databases were undertaken to
determine species of conservation significance previously recorded in or around the Study Area. For
the searches a shape file of the Study Area was provided to the DEC and an additional 2 km buffer
The following databases were searched for conservation significant flora taxa within this buffer:
The DEC’s Threatened (Declared Rare) Flora Database (DEFL); and
The DEC’s Western Australian Herbarium Specimen Database (WA HERB).
The following database was searched for conservation significant taxa by locations names:
The DEC’s Declared Rare and Priority Flora List (Atkins (2), 2008).
The following databases were searched for vegetation communities of conservation significance:
The DEC’s Threatened and Priority Ecological Community Database; and
The DEWHA Protected Matters Database.
Results from the first three searches listed above are summarised in Table C.1, Appendix C and
results of the Threatened and Priority Ecological Communities searches are summarised in Table 2.7.
VEGETATION AND FLORA ASSESSMENT
The first phase of the vegetation and flora of the Study Area was a quadrat based survey and was
completed from the:
of April to the 6
of May 2009 (Pastoral land area, Sections 3 and 4);
to the 13
of June 2009 (Pastoral land area, Sections 1 and 2); and
to the 21
of August 2009 (Freehold land area, Section 5).
quadrat locations are illustrated in Figure 3.1. Refer to sections 3.4.1 to 3.4.3 for further detail.
The second phase of the survey was a targeted threatened flora and unknown species transect
survey and was completed from the:
September 2009 (Pastoral land area, Sections 1 and 3);
to the 29
of October 2009 (Pastoral land area, Sections 4 and Freehold land area,
to the 24
March 2010 (Pastoral land area, Section 2).
Transect locations are illustrated in Figure 3.2 to Figure 3.6. One‐hundred and three person days
were spent on these surveys. See Section 3.4.4 for further detail.
The objectives of the surveys and subsequent report were to provide:
a review of plant species considered to be rare and endangered, or geographically restricted,
which are known to, or may occur, within the Study Area;