DRAFT Description, Threats Analysis and Priority Conservation Actions for
PLANT COMMUNITIES ON FERRICRETE/IRONSTONE IN SOUTH-WEST
WESTERN AUSTRALIA
The Threatened Species Scientific Committee is assessing a nomination to list as a national
ecological community a series of plant communities that occur on a restricted iron-rich
substrate in southern Western Australia. The potential national ecological community has five
regional component types, with significant variation in the species composition of each, and
distances separating each type of between approximately 90 and 610km. The following
document considers the combined entity encompassing the five regional types. Hereafter the
term “ecological community” should be understood to stand for the potential national
ecological community including those five regional type whose conformity as an entity with the
definition of an ecological community under the EPBC Act 1999 and its conservation status is
the subject of this document.
Contents
Plant communities on ferricrete/ironstone in south-west western australia ..................................1
Part A
1.
DESCRIPTION AND THREATS ANALYSIS ............................................................2
Description ........................................................................................................................2
Name of the ecological community ......................................................................................2
Location and climate .............................................................................................................2
Geology and landforms .........................................................................................................2
Hydrology..............................................................................................................................3
Vegetation .............................................................................................................................3
Key diagnostic characteristics and condition thresholds.......................................................5
2. Surrounding environment and national context .................................................................7
3.
Area critical to the survival of the ecological community..............................................8
4.
Geographic extent and distribution.................................................................................8
5.
Summary of threats .........................................................................................................9
6.
Other existing protection ................................................................................................9
7.
Summary of eligibility for listing against EPBC Act criteria .......................................10
Part B
Priority Conservation Actions .....................................................................................12
1.
Research priorities ........................................................................................................12
2.
Priority recovery and threat abatement actions ............................................................12
3.
Existing plans/management prescriptions ....................................................................13
Part C
Appendices ..................................................................................................................15
Appendix A - Species lists ......................................................................................................15
Appendix B - Detailed description of biology and ecological processes ................................17
Appendix C - Detailed description of national context ...........................................................19
Appendix D - Description of threats .......................................................................................21
Appendix E - Eligibility for listing against the EPBC Act criteria .........................................24
Part D
Bibliography ................................................................................................................27
PART A
1.
DESCRIPTION AND THREATS ANALYSIS
Description
Name of the ecological community
The name of the ecological community under assessment is Plant Communities on
Ferricrete/Ironstone in South-West Western Australia. The name was suggested by the
Western Australian Department of Environment and Conservation (DEC) as best describing the
ecological community. Throughout this document it is referred to as the ecological community
or the plant communities.
This ecological community was nominated for listing as threatened under the EPBC Act as part
of a process to streamline the listing of state endemic ecological communities under federal and
state processes.
Location and climate
The ecological community occurs as extremely restricted, disjunct patches within the
Southwest Botanical Province of Western Australia (Meissner and English 2005a,b). Within
this Province, there are restricted areas of ironstone and ferricrete soils which are associated
with unique plant communities. These are currently known to occur in a number of areas in the
south-west of Western Australia (WA) near Eneabba, at Gingin, at Busselton, the Scott River
and near Albany. The known plant communities associated with each of these locations are
referred to throughout this document as regional types, with patches within each type referred
to as occurrences. The ecological community is found in the Swan Coastal Plain, Geraldton
Sandplains, Jarrah Forrest and Warren IBRA bioregions (Interim Biogeographic
Regionalisation of Australia version 6.1). The south-west of WA has a mild Mediterranean
climate of warm, dry summers and cool, wet winters (Beard et al., 2000; Wheeler, 2002). Much
of the area receives in excess of 1000mm per year (average of 800-1500mm), the majority of
which falls between May and October (Wheeler, 2002).
Geology and landforms
The ecological community occurs as scattered patches on the coastal plain or on the footslopes
of scarps and plateaux in south-west WA. On the coastal plain of WA, deep layers of iron-rich
substrate are common, producing sumplands and damplands (Gibson et al., 2000). The soils
associated with this geology are composed of deep layers of Quaternary sand deposits (Poot et
al., 2008). However, the shallow soils associated with the ferricrete/ironstone substrate are
extremely restricted in south-west WA and the plant communities associated with them are
therefore also highly restricted (Gibson et al., 2000). The soils of the plant communities are
generally very shallow, ranging from 0-20cm (Poot et al., 2008), with soil depth ranging
throughout a patch of the ecological community. The soils are derived mainly from weathering
of the underlying ironstone rock (Poot et al., 2008). The ferricrete/ironstone substrate can occur
as a mosaic with other substrates, resulting in pockets or patches of deeper soil. Outcropping of
ferricrete and ironstone rocks in the ecological community is common.
Around Gingin, Busselton, Scott River and Albany, the ecological community occurs on very
shallow, reddish, loamy sands over massive ironstone rock (Poot et al., 2008). Ironstone soils
contain more than 60% of ironstone gravel throughout the profile and have a distinct red-brown
colour (CSIRO, 1983; Poot et al., 2008). Ironstone is thought to have formed in bogs, with iron
being deposited by water percolating through the soil, followed by evaporation, to create a very
hard stony habitat (Gibson et al., 2000). Around Eneabba, the ecological community occurs on
very shallow red and brown loamy sands over ferricrete (Hamilton-Brown et al., 2004).
Ferricrete is formed in the soil profile at the water table when iron oxides accumulate and
2
cement together to form a gravely or nodule-rich band (Hamilton-Brown et al., 2004). The
formation of the ferricrete/ironstone substrate is an ongoing process.
Hydrology
South-west WA receives an average of 800-1500mm of rain per year, most of which falls
between May and October (Wheeler, 2002). The ironstone and ferricrete substrate on which the
plant communities occur produces a specific hydrological regime. The shallow soil layer above
the substrate impedes drainage, leading to inundation of the ecological community during
heavy or prolonged rainfall (Meissner and English, 2005b). During the winter months, the plant
communities experience numerous waterlogging and drainage events (Poot et al., 2008). The
watertable is close to or above the surface for several months between May-October, drying out
at the surface in summer (Smith and Ladd, 1994; Luu and English, 2004; Meissner and English,
2005a,b). The depth and length of inundation varies between occurrences, with some having
very little or no standing water and others having obvious pools of water (Luu and English,
2004).
The plant communities are dependent on groundwater for formation and maintenance of the
ferricrete or ironstone substrate (Hamilton-Brown et al., 2004). Groundwater generally comes
close to or is above the surface during the winter months. Surface water which originates from
rainfall during wetter months can also make its way down into the groundwater (Meissner and
English, 2005b). As there are connections between the surface and groundwater through the
ironstone or ferricrete, then both these sources affect the quantity and quality of water in the
plant communities (Meissner and English, 2005b).
The occurrence of the plant community at Gingin is located on and connected to the Gnangara
Mound, a shallow groundwater aquifer (Meissner and English, 2005b). Local hydrogeology is
therefore likely to be very important in maintaining the community (Meissner and English,
2005b). The ferricrete plant communities around Eneabba are associated with organic mound
springs which experience continuous discharge of groundwater in raised areas of peat (Rees
and Broun, 2005). The groundwater which feeds these springs is related to the aquifer which
forms and maintains the ferricrete (Hamilton-Brown et al., 2004). Water from these mound
springs also flows into adjacent ferricrete plant communities adding to inundation in the wetter
months. The southern ironstones near Busselton have also been identified as groundwater
dependent ecosystems (Meissner and English, 2005a) and a suite of aquifers within sand or
sandstone occur beneath the Scott River plant communities (Luu and English, 2004).
Vegetation
The ecological community is variable in terms of species composition and structure. This
variation is found among regional types as well as among occurrences. Composition and
structure also varies in response to disturbances such as fire and clearing. The plant
communities are generally heathlands or shrublands with a proliferation of flowering annuals in
the spring following winter inundation. Plants from the families Proteacae and Epacridacae
make up the majority of woody vegetation. Low trees and/or shrubs can form a sparse to dense
canopy, with grasses, herbs and smaller shrubs in the understorey. Annual herbs flower in the
spring when the soil has dried out, and set seed in summer, generally dying out by autumn. The
floral composition of a particular occurrence is thought to be a response to soil depth and
degree of waterlogging (Smith and Ladd, 1994).
The Plant Communities on Ferricrete/Ironstone in South-West Western Australia ecological
community is currently known to include the following WA ecological communities:
Shrublands and woodlands on Perth to Gingin ironstone (Perth to Gingin ironstone
association) of the Swan Coastal Plain
3
This regional type consists of three occurrences within the Shire of Gingin, on heavy clay
soils on the eastern side of the Swan Coastal Plain. It experiences shallow seasonal
inundation with fresh surface water, and groundwater may come very close to or may
reach the surface in wetter months (Meissner and English, 2005b). It is the only plant
community on ironstone soils that is characterised by Rhodanthe spp. (massed
everlastings) in the understorey (Meissner and English, 2005b). This everlastingdominated herb layer does not occur on deeper soils adjoining the ironstone areas.
The vegetation is made up of a sparse shrubland over an herbaceous layer of annuals.
Typical and common native species in the community are the shrubs: Kunzea aff. recurva,
Grevillea curviloba subsp. incurva (narrow curved-leaf grevillea), Melaleuca viminea
(mohan), Acacia saligna (golden wreath wattle), Jacksonia furcellata (grey stinkwood),
Grevillea obtusifolia (Gingin gem) and Banksia sessilis (parrot bush); and the herbs:
Rhodanthe manglesii (pink sunray), Tribonanthes australis and Isotropis cuneifolia subsp.
glabra (granny bonnets).
Shrublands on southern Swan Coastal Plain ironstones
The plant communities of this regional type are species-rich and are found on the southern
Swan Coastal Plain bioregion near Busselton. Much of the high species diversity comes
from annuals and geophytes (Phillimore et al., 2001). Many of the plant species in these
communities are endemic to the region, and in some cases, to specific patches. Many of the
plant species are susceptible to dieback disease and/or are obligate seeders.
The vegetation is sparse to dense shrubland over an herbaceous layer. Typical and common
native species in the community are the shrubs: Kunzea aff. micrantha, Pericalymma
ellipticum (swamp teatree), Hakea spp., Hemiandra pungens (snakebush) and Viminaria
juncea (swish bush) and the herbs: Aphelia cyperoides, Centrolepis aristata (pointed
centrolepis). The introduced species Hypochaeris glabra (smooth catsear) is also common
in the community (Meissner and English, 2005a).
Ferricrete floristic community (Rocky Springs type)
The plant communities of this regional type are found on infrequently inundated red and
brown sandy loams over ferricrete soils in the Eneabba region. Surrounding vegetation is
generally sclerophyllous shrubland, or ‘kwongan’.
The vegetation of this regional type is a tall, generally dense shrubland. The occurrences
are dominated by Acacia blakelyi (Blakely’s wattle), Allocasuarina campestris (tamma),
Banksia strictifolia and Labichea lanceolata subsp lanceolata (Hamilton-Brown et al.,
2004). Associated species include Alyogyne hakeifolia (Australian hibiscus), Borya
sphaerocephala (pincushions), Isotoma hypocrateriformis (Woodbridge poison),
Petrophile seminuda, Stylidium dichotomum (pins and needles), Thysanotus patersonii
(twining fringe-lily) and Waitzia paniculata (woolly waitzia) (Hamilton-Brown et al.,
2004).
Scott River ironstone association
The plant communities of this regional type are found on the Scott Coastal Plain near
Augusta. The occurrences are highly variable in plant species composition, probably as a
result of variation in soil type and depth (Luu and English, 2004).
The vegetation of this regional type is heathlands and shrublands, with dominant species
depending on the degree of waterlogging (Luu and English, 2004). The occurrences are
variously dominated by Melaleuca preissiana (moonah), Hakea tuberculata, Kunzea
micrantha or Melaleuca incana subsp. Gingilup (grey honey-myrtle).The understorey is
generally dominated by Loxocarya magna. All occurrences (except the long inundated
4
wetlands and dense thickets) have a diverse annual flora of Stylidium spp. (trigger-plants),
Centrolepis spp., Schoenus spp. (bog-rush) and Brizula spp. (Luu and English, 2004).
Wet ironstone heath community (Albany district)
This plant community is found north of Albany in the Porongurups (DEC, 2012b). It is
located in a valley floor of the Twins Creek Conservation Reserve, adjacent to a stream
(CALM, 2006).
The vegetation of this regional type is heath dominated by Kunzea recurva, K. preissiana,
K. micrantha, Hakea lasiocarpha (long styled hakea), H. tuberculata, H. oldfieldii, H.
cucullata (scallop hakea), H. sulcata (furrowed hakea), Petrophile squamata, Dryandra
tenuifolia sp. tenuifolia, Adenanthos apiculatus, Melaleuca suberosa (cork bark honey
myrtle), M. violacea (violet paperbark) and Gastrolobium spinosum (prickly poison). The
understorey is made up of various moisture-loving species including sedges, Drosera spp.
(sundew), mosses and several orchid species (CALM, 2006).
Key diagnostic characteristics and condition thresholds
The ecological community no longer exists at many sites where it was formerly present. In
many cases, the loss is irreversible because sites have been permanently cleared or have
undergone some other substantial modification that has removed their natural hydrological and
biological characteristics. In other cases, the ecological community now exists in a disturbed or
degraded state, and may be so degraded that it is impractical to restore it.
National listing focuses legal protection on the remaining occurrences of the ecological
community that are functional, relatively natural and in relatively good condition. Condition
thresholds help identify a patch of the threatened ecological community and when the EPBC
Act is likely to apply to an ecological community. They provide guidance for when a patch of a
threatened ecological community retains sufficient conservation values to be considered as a
Matter of National Environmental Significance, as defined under the EPBC Act. This means
that the protection provisions of the EPBC Act would be focussed on the most valuable
elements of Australia’s natural environment, while heavily degraded patches, which do not
meet the condition thresholds, would be largely excluded from EPBC Act protection. The
condition thresholds for the ecological community are based on those developed and used to
assess condition by the WA Department of Environment and Conservation.
Although highly degraded patches would not be a part of the ecological community listed under
the EPBC Act, it is recognised that patches that do not meet the condition thresholds may still
retain important natural values. As such, these patches should not be excluded from recovery
and other management actions (see also the Surrounding environmental and landscape context
below).
Step 1 Key diagnostic characteristics
The key defining attributes for the ecological community are:



It occurs in the south-west botanical province of Western Australia (as per Beard et al.,
2000);
Soils are shallow, loamy sands above a substrate of ironstone or ferricrete at or near the
surface;
Rainfall is winter-dominated, mainly falling between May and October;
5




Sites are seasonally inundated in winter and may be waterlogged at this time;
Vegetation is generally shrubland or heathland with an open to closed structure;
A shrub or heath layer is present at all times, typically dominated by a combination of
species from the genera: Acacia, Adenanthos, Allocasuarina, Banksia, Dryandra,
Gastrolobium, Grevillia, Hakea, Hemiandra, Kunzea, Jacksonia, Labichea, Loxocarya,
Melaleuca, Pericalymma, Petrophile and/or Viminaria; and
An annual herbaceous layer is present in the dry season (Oct-April).
Step 2 Condition thresholds
The listed ecological community is limited to patches that meet the description, key
diagnostic characteristics and the following condition thresholds.
To be considered as part of the ecological community a patch should meet at least the Good
Condition category of the DEC ecological community condition criteria (Government of
Western Australia, 2000).
DEC assesses ecological community condition based on the following Vegetation Condition
descriptions:
Pristine: Pristine or nearly so, no obvious signs of disturbance.
Excellent: Vegetation structure intact, disturbance is only affecting individual species
and weeds are non-aggressive species.
Very Good: Vegetation structure altered, with obvious signs of disturbance. For
example, disturbance to vegetation structure caused by repeated fires, the presence of
some more aggressive weeds, dieback, logging and/or grazing.
Good: Vegetation structure significantly altered by very obvious signs of multiple
disturbance. Retains basic vegetation structure or the ability to regenerate it. For
example, disturbance to vegetation structure caused by very frequent fires, the presence
of some very aggressive weeds at high density, partial clearing, dieback and/or grazing.
Degraded: Basic vegetation structure severely impacted by disturbance. Scope for
regeneration but not to a state approaching good condition without intensive
management. For example, disturbance to vegetation structure caused by very frequent
fires, the presence of very aggressive weeds, partial clearing, dieback and/or grazing.
Completely degraded: The structure of the vegetation is no longer intact and the area
is completely or almost completely without native species. These areas are often
described as “parkland cleared” with the flora comprising weed and crop species with
isolated native trees or shrubs.
The following information should also be taken into consideration when applying
condition thresholds.

A patch of the listed ecological community is defined as a discrete and continuous area
of the ecological community, as described, and does not include substantial elements of
other ecological communities. As the ecological community occurs in restricted
locations that can be very small, no minimum patch size would be recommended. A
patch of the listed ecological community may include small-scale disturbances, such as
tracks or breaks, that do not alter its overall functionality, for instance the easy
movement of wildlife or dispersal of plant propagules, and may also include small-scale
variations in vegetation that are noted in the Description and National Context. In
particular, there can be a mosaic of different soil types and depths within a patch that
6
will produce differences in vegetation structure; however the whole patch should be
considered part of the ecological community.

Buffer zones around the ecological community are important for protection against
further weed invasions and disruptions to hydrology. To assist in the preservation of the
patch and persistence of the ecological community, it is recommended that a buffer
zone of at least 50 m be maintained from the outer edge of the patch. However, the
width of the buffer required may be greater, depending on the type of development
proposed, the local hydrology, the vegetation in the buffer and other factors.

The sampling protocol involves developing a quick/simple map of the vegetation
condition, landscape qualities and management history (where possible) of the site. The
area with the most apparent native vegetation cover in the ground layer should be
adequately sampled to determine estimates of ground cover.

Timing of surveys is an important consideration because the ecological community can
be variable in its appearance between wet and dry seasons and between years depending
on drought-rain cycles. Timing of surveys should also consider the detectability of mid
and ground layer species at different times of their life cycle, or their recovery after
recent disturbances (natural or human-induced) to the ecological community.
2.
Surrounding environment and national context
The Good condition class (or category) outlined above is the minimum level at which patches
are to be considered under the EPBC Act for actions that may require referral to the Australian
Government. The descriptions for Very Good, Excellent and Pristine categories represent a
more ideal state of the ecological community. In addition the larger and more diverse a patch is,
the greater the likely biodiversity value and its sustainability. Patches that link native remnants
in the landscape are also important as wildlife habitat and for the viability of the ecological
community into the future.
Therefore, in the context of actions that may have significant impacts and require approval
under the EPBC Act, it is important to consider the environment surrounding the listed patches
that meet the Good, Very Good, Excellent and Pristine condition classes (categories). Some
patches that meet the condition thresholds above will occur in isolation and require protection,
as well as priority actions, to link them with other native vegetation. Other patches will have
additional conservation value through being connected to other intact native vegetation. In
these instances, the following indicators should be considered when assessing the impacts of
actions or proposed actions under the EPBC Act, or when considering recovery, management
and funding priorities for a particular patch:

Large size and/or with a large area to boundary ratio – larger area/boundary ratios are
less exposed and more resilient to edge effect disturbances such as weed invasion and
other anthropogenic impacts;

Areas of minimal weeds and feral animals or where they can be easily managed;

Connectivity to other, surrounding native vegetation remnants;

Patches that occur in those areas in which the ecological community has been most
heavily cleared and degraded, or that are at the natural edge of its range, and components
of the ecological community that are the least protected in conservation reserves; and/or

Patches that contain listed threatened species (state or national).
7
3.
Area critical to the survival of the ecological community
Areas that meet the condition thresholds and the buffer zone (page 6) are considered critical to
the survival of this ecological community. Abiotic features including the soil type, substrate
and the surface, groundwater and groundwater catchment hydrology that maintains the
vegetation of the ecological community are also considered critical to the ecological
community’s survival. Additional areas such as adjoining native vegetation and areas that meet
the description of the ecological community but not the condition thresholds are also
considered important to the survival of the ecological community. It is also important to
consider the surrounding environment and landscape context as outlined on page 7.
4.
Geographic extent and distribution
The ecological community occurs naturally as isolated patches due to the restricted nature of
the ferricrete/ironstone substrate. However, it has undergone a decline in distribution, largely as
a result of clearing for agriculture. Table 1 below presents information on the pre-European
extent and current extent, based on information provided by DEC (DEC, 2012c) and Meissner
and English (2005a). The figures have been calculated for each regional type that comprises the
ecological community. The Ferricrete floristic community is thought to be largely uncleared
since pre-European times. There is no pre-European extent data for the Wet ironstone heath
community (Albany district). However, the current extent is estimated at 53-75ha based on
information provided by DEC (2012c). For the purposes of Table 1, it has been assumed that
this regional type has not declined in extent.
The remaining known patches of the ecological community occur on a variety of tenures from
private, freehold land to Nature Reserves managed by DEC. The available patch size data
provided by DEC (2012c) and presented in Table 2 indicate a high degree of fragmentation
across the range of the ecological community with most patches (88%) less than 50ha.
Table 1. Estimates of pre-European and current extent
Regional type
Pre-European
extent (ha)
Current total
area (ha)
Percentage
decline
Shrublands and woodlands on Perth to Gingin
ironstone (Perth to Gingin ironstone association) of
the Swan Coastal Plain
900-1500
27-51
94-98
Shrublands on southern Swan Coastal Plain
ironstones
1200
130-164
86-89
Ferricrete floristic community (Rocky Springs
type)
395-473
395-473
0-16
Scott River ironstone association
1100-1700
276-404
63-84
Wet ironstone heath community (Albany district)
53-75
53-75
0-29
3648-4948
881-1167
68-82
Total
Table 2. Patch data for the ecological community
Patch size (ha)
<1
1 - 10
10 - 20
Number of patches
Percentage of total
patches
10
27
10
Cumulative percentage
17
46
17
17
63
80
8
20-50
>50
Total
5.
5
7
59
8
12
100
88
100
100
Summary of threats
The main ongoing threats to the ecological community are:




Land clearing;
Dieback disease caused by root-rot fungus (Phytophthora cinnamomi);
Grazing by native and non-native animals; and
Weed invasion.
The ecological community is potentially threatened by:



Altered fire regimes;
Hydrological changes; and
Climate change.
Further details about the threats to the ecological community can be found at Appendix D.
6.
Other existing protection
Relationship to nationally-listed ecological communities
Two of the regional types that make up the ecological community were previously listed as
separate endangered ecological communities under the EPBC Act:


Shrublands and woodlands on Perth to Gingin ironstone (Perth to Gingin ironstone
association) of the Swan Coastal Plain; and
Shrublands on southern Swan Coastal Plain ironstones.
Relationship to state-listed ecological communities
Four regional types included in the national ecological community are listed in WA as
Threatened Ecological Communities (TECs) endorsed in December 2006 (DEC 2012a). Table
3 below shows these ecological communities and their status.
Table 3. Ecological community regional types listed in WA.
TEC name
Shrublands and woodlands on Perth to Gingin ironstone
Shrubland association on southern Swan Coastal Plain ironstone
(Bussleton area) (southern ironstone association)
Ferricrete floristic community (Rocky Springs type)
Scott River ironstone association
DEC community
identifier
NTHIRON
SCP10b
Ferricrete
SCOTT
IRONSTONE
WA status
Critically
Endangered
Critically
Endangered
Vulnerable
Endangered
One regional type included in the ecological community is listed on the WA DEC website as
Priority 1 for assessment as a threatened ecological community (DEC, 2012b): Wet ironstone
heath community (Albany district). There has been do endorsement of TECs for listing in WA
since 2006. There is currently no legislation specifically covering the protection of listed TECs
in WA. However, informal non-statutory processes are in place.
9
Listed threatened flora species
Table 4 below provides a list of flora species protected under state and/or national legislation,
by regional type.
Table 4. Threatened plant species known to occur in the ecological community.
Scientific Name
Common name
Shrublands and woodlands on Perth to Gingin ironstone
Grevillea curviloba subsp. incurva
narrow curved-leaf grevillea
WA
National
DRF
E
Shrubland association on southern Swan Coastal Plain ironstone (Bussleton area) (southern ironstone
association)
Eremophila microtheca
heath-like eremophila
DRF
Brachyscias verrucundus
ironstone brachyscias
DRF
CE
Gastrolobium modestum
broad-leaved gastrolobium
DRF
V
Gastrolobium papilio
butterfly-leaved gastrolobium
DRF
E
Chamelaucium roycei
Royce’s waxflower
DRF
V
Darwinia whicherensis
abba bell
DRF
E
Banksia nivea subsp. uliginosa
swamp honeypot
DRF
E
Banksia squarrosa subsp. argillacea
Whicher Range dryandra
DRF
V
Grevillea elongata
ironstone grevillea
DRF
V
Grevillea maccutcheonii
McCutcheon’s grevillea
DRF
E
Lambertia echinata subsp. occidentalis
western prickly honeysuckle
DRF
E
Petrophile latericola
laterite petrophile
DRF
E
Brachyscias verecundus
ironstone brachyscias
DRF
CE
Scott River ironstone association
Banksia nivea subsp. uliginosa
Darwinia ferricola
Lambertia orbifolia subsp. Scott River
Plains
swamp honeypot
Scott River darwinia
roundleaf honeysuckle
DRF
DRF
DRF
E
E
E
Legend: WA= Wildlife Conservation Act 1990; National= EPBC Act; DRF= Declared Rare
Flora; CE= critically endangered; E= endangered; V= vulnerable.
7.
Summary of eligibility for listing against EPBC Act criteria
Criterion 1 – Decline in geographic distribution
Based on available data for the known occurrences, the ecological community has declined in
extent from approximately 3600-4900 to 900-1200ha (Table 1). This represents a substantial
decline in the order of 68-82%. It is important to note that some patches of the ecological
community that are included in the data above may not meet the condition thresholds, such as
patches with a high degree of disturbance, so the decline may actually be more than is
estimated. As there is no accurate pre-European extent data for the Ferricrete floristic
community (Rocky Springs type) or the Wet ironstone heath community (Albany district), the
actual decline may be further still.
The ecological community appears to have undergone a substantial decline in geographic
distribution. Therefore the ecological community would meet the relevant elements of Criterion
1 to make it eligible for listing as vulnerable.
Criterion 2- Small distribution coupled with demonstrable threat
The remaining area of occupancy for the ecological community is approximately 900-1200ha
as presented in Table 1. The lower end of the estimate is indicative of a very restricted
geographic distribution (i.e., total occupancy ≤ 100ha). An analysis of patch size based on DEC
data indicates that there are 59 patches of the ecological community remaining (Table 2). Of
the patches remaining, 63% are less than 10ha and 88% are less than 50ha. The available patch
10
size data indicate a high degree of fragmentation across the range of the ecological community
consistent with a restricted geographic distribution (i.e. patch size is typically less than 100ha).
The ecological community appears to have a very restricted geographic distribution, based on
the generally small and fragmented size distribution of patches. It appears that the demonstrable
ongoing threats detailed in Appendix D could cause the ecological community to become lost
in the near future. Therefore, the ecological community would meet the relevant elements of
Criterion 2 to make it eligible for listing as endangered under this criterion.
Criterion 3 – Loss or decline of functionally important species
The ecological community has variable species composition across its geographic range and it
is not possible to identify a single species or suite of species that has critical functions to the
ecological community as a whole.
There is no information available to the assessment judge if the ecological community has
undergone a loss or decline in functionally important species. Therefore, as the ecological
would not have been demonstrated to meet any of the required elements of Criterion 3, it would
not be eligible for listing in any category under this Criterion.
Criterion 4- Reduction in community integrity
Weed incursion, dieback disease and changes to hydrological regimes all have the potential to
reduce the integrity of the ecological community by disruption of important community
processes and to degrade the ecological community.
However, there is not enough evidence to indicate that these factors are having an impact on
the whole of the ecological community. Therefore, as the ecological community would not
have been demonstrated to meet any of the required elements of Criterion 4, it would not be
eligible for listing in any category under this Criterion.
Criterion 5 – Rate of continuing detrimental change
The ecological community is suspected to be undergoing continuing detrimental change
(through clearing, weed incursions, grazing and changes to hydrological regimes) over the
immediate past.
However, there are no data available to the assessment to judge the rate of continuing
detrimental change experienced by the ecological community. Therefore, as the ecological
community would not have been demonstrated to meet any of the required elements of
Criterion 5, it would not be eligible for listing in any category under this Criterion.
Criterion 6- Quantitative analysis showing probability of extinction
There is no quantitative data available to the assessment to evaluate this ecological community
under this criterion. Therefore, it would not be eligible for listing under this criterion.
Further details about the ecological community’s eligibility for listing can be found in
Appendix E
11
PART B
1.
PRIORITY CONSERVATION ACTIONS
Research priorities
Research priorities that would inform future regional and local priority actions include:
 Design and implement a monitoring program or, if appropriate, support and enhance
existing programs.
 More precisely assess distribution, ecological requirements and the relative impacts of
threatening processes.
 Undertake survey work in suitable habitat and potential habitat to locate any additional
populations/occurrences/remnants.
2.
Priority recovery and threat abatement actions
The following priority recovery and threat abatement actions could be done to support the
recovery of the Plant communities on ferricrete/ironstone in southwest Western Australia
ecological community.
Habitat Loss, Disturbance and Modification







Monitor known populations to identify key threats.
Monitor the progress of recovery, including the effectiveness of management actions and
the need to adapt them if necessary.
Ensure road widening and maintenance activities (or other infrastructure or development
activities) involving substrate or vegetation disturbance in areas where the ecological
community occurs do not adversely impact on known patches.
Manage any changes to hydrology that may result in changes to water table levels and/or
increased run-off, salinity, sedimentation or pollution.
Manage any disruptions to water flows.
Investigate formal conservation arrangements, management agreements and covenants on
private land, and for crown and private land investigate inclusion in reserve tenure if
possible.
Manage any other known, potential or emerging threats.
Diseases and Fungi


Develop and implement suitable hygiene protocols to protect known sites from further
outbreaks of dieback caused by Phytophthora cinnamomi.
Use control methods such as spraying of phosphate to control identified patches infected
with dieback caused by Phytophthora cinnamomi.
Trampling, Browsing or Grazing


Develop and implement a stock management plan for roadside verges and travelling stock
routes.
Develop and implement a management for the control and eradication of rabbits in the
region.
Invasive Weeds
12


Manage sites to prevent introduction or further spread of invasive exotic weeds, and
targeted control of existing key weeds which threaten the ecological community, using
appropriate methods.
Ensure chemicals or other mechanisms used to eradicate weeds do not have a significant
adverse impact on native ferricrete/ironstone species.
Fire



Develop and implement a suitable fire management strategy for Plant communities on
ferricrete/ironstone in southwest Western Australia.
Identify appropriate intensity and interval of fire to promote seed germination and
vegetation regeneration.
Where appropriate provide maps of known occurrences to local and state Rural Fire
Services and seek inclusion of mitigation measures in bush fire risk management plan(s),
risk register and/or operation maps.
Conservation Information


Raise awareness of Plant communities on ferricrete/ironstone in southwest Western
Australia within the local community.
Maintain liaisons with private landholders and land managers of land on which populations
occur.
This list does not necessarily encompass all actions that may be of benefit to the Plant
communities on ferricrete/ironstone in southwest Western Australia, but highlights those that
are considered to be of highest priority at the time of preparing the Conservation Advice.
3.
Existing plans/management prescriptions
Hamilton-Brown S, Broun G and Rees R (2004). Ferricrete floristic community (Rocky Springs
type). Interim Recovery Plan 2004-2009. Department of Conservation and Land
Management, Wanneroo.
Available on the internet at:
http://www.dec.wa.gov.au/pdf/plants_animals/threatened_species/irps/tec/ferricrete_15
4.pdf
Luu R and English V (2004). Scott River ironstone association. Interim Recovery Plan 20042009. Department of Conservation and Land Management, Wanneroo.
Available on the internet at:
http://www.dec.wa.gov.au/pdf/plants_animals/threatened_species/irps/tec/scott_ironsto
ne_irp217.pdf
Meissner R and Engish V (2005a). Shrubland association of southern Swan Coastal Plain
ironstone (Busselton area) (southern ironstone association). Interim Recovery Plan
2005-2010. Department of Conservation and Land Management, Wanneroo.
Available on the internet at:
http://www.dec.wa.gov.au/pdf/plants_animals/threatened_species/irps/tec/southern_iron
stone_irp215_update.pdf
Meissner R and English V (2005b). Shrublands and woodlands on Perth to Gingin ironstone.
Interim Recovery Plan 2005-2010. Department of Conservation and Land Management,
Wanneroo.
Available on the internet at:
13
http://www.dec.wa.gov.au/pdf/plants_animals/threatened_species/irps/tec/northn_ironst
one_irp197update.pdf
These prescriptions were current at the time of publishing; please refer to the relevant agency’s
website for any updated versions.
14
PART C
APPENDICES
Appendix A - Species lists
Table 1. Characteristic plant species, by regional type (Hamilton-Brown et al., 2004; Luu and
English, 2004; Meissner and English, 2005a,b). *indicates that the species is not native
Regional type
Name
Common name
Shrublands and woodlands on Perth to Gingin ironstone
Shrubs
Kunzea aff. recurva
Grevillea curviloba subsp. incurva
narrow curved-leaf grevillea
Melaleuca viminea
mohan
Acacia saligna
golden wreath wattle
Jacksonia furcellata
grey stinkwood
Grevillea obtusifolia
Gingin gem
Banksia sessilis
parrot bush
Herbs
Rhodanthe manglesii
pink sunray
Tribonanthes australis
Isotropis cuneifolia subsp. glabra
granny bonnets
Shrubland association on southern Swan Coastal Plain ironstone (Bussleton area) (southern ironstone
association)
Shrubs
Kunzea aff. micrantha
Pericalymma ellipticum
swamp teatree
Hakea spp.
Hemiandra pungens
snakebush
Viminaria juncea
swish bush
Herbs
Aphelia cyperoides
Centrolepis aristata
pointed centrolepis
*Hypochaeris glabra
smooth catsear
Ferricrete floristic community (Rocky Springs type)
Shrubs
Acacia blakelyi
Blakely’s wattle
Allocasuarina campestris
tamma
Dryandra stricta
Labichea lanceolata subsp lanceolata
Alyogyne hakeifolia
Australian hibiscus
Borya sphaerocephala
pincushions
Isotoma hypocrateriformis
Woodbridge poison
Petrophile seminuda
Herbs
Stylidium dichotomum
pins and needles
Thysanotus patersonii
twining fringe-lily
Waitzia paniculata
woolly waitzia
Scott River ironstone association
Shrubs
Melaleuca preissiana
moonah
Hakea tuberculata
Kunzea micrantha
Melaleuca incana subsp Gingilup
grey honey-myrtle
Herbs
Stylidium spp.
trigger-plants
Centrolepis spp.
Schoenus spp.
bog-rushes
Brizula spp.
Wet ironstone heath community (Albany district)
Shrubs
Kunzea recurva,
Kunzea preissiana
Kunzea micrantha
Hakea lasiocarpha
long styled hakea
Hakea tuberculata
Hakea oldfieldii
Hakea cucullata
scallop hakea
Hakea sulcata
furrowed hakea
Petrophile squamata
15
Herbs
Dryandra tenuifolia sp. tenuifolia
Adenanthos apiculatus
Melaleuca suberosa
Melaleuca violacea
Gastrolobium spinosum
Drosera spp.
cork bark honey myrtle
violet paperbark
prickly poison
sundew
16
Appendix B - Detailed description of biology and ecological processes
Vegetation dynamics
The Southwest Botanical Province where the ecological community occurs is an internationally
recognised biodiversity hotspot (Beard et al., 2000). The generally poor soils of the south-west
WA region are thought to have produced plant species that are highly specialised with many
species which are endemic, not only to the region, but also to specific occurrences (Beard et al.,
2000). The plant communities are restricted in occurrence and geographically widespread. This
isolation often results in species with restricted distributions and the ecological community
contains a relatively high proportion of endemic species. Gibson et al. (2000) found twenty taxa
that were endemic or had their major distribution centred on ironstone communities of the
Swan Coastal Plain (this includes the regional types around Gingin and Busselton) and/or the
Scott River Plain. Some of these species also occur in the plant communities on ironstone near
Albany (DEC, 2012b). Table 1 below lists those species in the ecological community which are
restricted to, or have their major distribution centred on, ironstone soils.
Table 1. Taxa restricted or largely restricted to the ecological community on the Swan Coastal
Plain, Scott Coastal Plain and/or near Albany (Gibson et al., 2000; DEC, 2012b).
Species
Andersonia ferricola ms
Gastrolobium modestum
Gastrolobium papilio
Chamelaucium roycei ms
Darwinia whicherensis
Banksia squarrosa subsp.
argillacea
Grevillea elongata
Grevillea maccutcheonii
Hakea oldfieldii
Common name
Lambertia echinata subsp.
occidentalis
Petrophile latericola ms
Brachyscias verecundus
Banksia nivea subsp. uliginosa
western prickly honeysuckle
broad-leaved gastrolobium
butterfly-leaved gastrolobium
Royce’s waxflower
abba bell
Whicher Range dryandra
ironstone grevillea
Maccutcheon’s grevillea
laterite petrophile
ironstone brachyscias
swamp honeypot
Calothamnus sp. Scott River
Chordifex isomorphus
Loxocarya magna
Darwinia ferricola ms
Grevillea manglesioides subsp.
ferricola
Hakea tuberculata
Scott River bell
Lambertia orbifolia
Melaleuca incana subsp. Gingilup
roundleaf honeysuckle
grey honey-myrtle
Location
Swan Coastal Plain
Swan Coastal Plain
Swan Coastal Plain
Swan Coastal Plain
Swan Coastal Plain
Swan Coastal Plain
Endemic
Yes
No
Yes
No
Yes
Yes
Swan Coastal Plain
Swan Coastal Plain
Swan Coastal Plain and
Albany
Swan Coastal Plain
Yes
Yes
No
Swan Coastal Plain
Swan Coastal Plain
Swan and Scott Coastal
Plains
Swan and Scott Coastal
Plains
Swan and Scott Coastal
Plains
Swan and Scott Coastal
Plains
Scott Coastal Plain
Scott Coastal Plain
Yes
Yes
Yes
Scott Coastal Plain and
Albany
Scott Coastal Plain
Scott Coastal Plain
No
Yes
Yes
No
No
Yes
Yes
Yes
Yes
The reason for this relatively high number of endemic species is likely due to the
environmental constraints placed on the ecological community. Poot et al. (2008) note that the
need to cope with waterlogging in winter and drought in summer, shallow soil, and potentially
high levels of iron in plant tissues, are likely to lead to species specifically adapted to that
environment. The special adaptations of plant species to these environmental constraints may
17
actually be a disadvantage on deeper soils, which may explain why some species do not occur
anywhere else (Poot and Lambers, 2008).
Many of the perennial woody species in the plant communities have morphological or
physiological adaptations to the shallow ironstone/ferricrete soils and seasonal waterlogging
(e.g. Kunzea aff. recurva) (Smith and Ladd, 1994; Meissner and English, 2005b). As discussed
under Geology the soil in the ecological community is generally very shallow. Therefore, plants
that establish on this shallow soil need to have special adaptations. Poot and Lambers (2008)
found that shallow-soil endemic plants have a specialised root system that allows them to
explore a large area, which presumably increases their chances of locating water through cracks
in the rock.
The shallow soil and impenetrable nature of the ironstone/ferricrete substrate mean that plant
roots are generally unable to obtain enough water to survive during the dry summer months
(Smith and Ladd, 1994). However, it is thought that the inundation in the wetter months
provides enough water for plant species to survive the hot, dry summers (Poot and Lambers,
2008). In addition the herb layer, which is a major distinguishing characteristic of this
community, would probably not occur in late winter and early spring without winter inundation
(Meissner and English 2005a, b). The duration and degree of seasonal waterlogging is also an
important determinant of species composition (Smith and Ladd, 1994). The water table can be
at or above the surface at this time, meaning plant roots may be submerged for months at a
time. The roots of many plant species are not able to survive in the anaerobic conditions created
by waterlogging and many seedlings of sclerophyllous trees are not able to establish in areas
that are waterlogged for several months of the year (Smith and Ladd, 1994). It seems that many
plant species which occur in the ecological community have root systems that are adapted to
this annual inundation.
Examples of faunal roles and interactions
No surveys have been conducted specifically on the fauna of this ecological community;
therefore there is very limited information available. No fauna species are known to be
exclusively restricted to the ecological community. A number of invertebrate species are found,
including ants and spiders (N. Burton pers obs.). Some fauna species are likely to be visitors to
the ecological community, for food and shelter, or using patches as stepping-stones to preferred
habitat. For example, parrots such as Calyptorhynchus baudinii (Baudin’s black cockatoo) have
been seen feeding within the ecological community (N. Burton pers obs.). Macropus rufus (red
kangaroos) are frequent visitors, grazing on the grasses and resting in the ecological community
(J. Pryde pers comm.).
18
Appendix C - Detailed description of national context
Distribution
The ecological community occurs as extremely restricted, disjunct patches within the
Southwest Botanical Province of Western Australia (Meissner and English, 2005a,b). Within
this Province, there are restricted areas of ironstone and ferricrete soils which are associated
with unique plant communities. These occur in a number of areas: near Eneabba, at Gingin, at
Busselton, the Scott River and near Albany. The ecological community is known to occur in
the Swan Coastal Plain, Geraldton Sandplains, Jarrah Forrest and Warren IBRA bioregions
(Interim Biogeographic Regionalisation of Australia version 6.1).
There may be other occurrences of the ecological community in other locations throughout
south-west WA that have not been adequately documented. Patches which meet the
Description, Key Diagnostics and Condition Thresholds in Part A are considered to be part of
the listed ecological community.
Landuse history
The ecological community is generally unsuitable for agriculture due to the shallow soils which
overlie the ironstone/ferricrete substrate. However, the surrounding landscape in which
occurrences are found is generally productive and much of the vegetation has been removed
since European settlement for grazing and cropping. This is especially the case in the
agricultural areas north and south of Perth around Gingin, Busselton and the Scott River. In
some cases, the ironstone substrate has been dug up and removed to make the soil more
productive. In these cases, the ecological community is irretrievable. As many of the patches
of the ecological community are surrounded by grazing and cropping, these patches are subject
to edge effects which exacerbate threatening processes, such as weed invasion.
Relationships to State-listed ecological communities
Four components of the national ecological community are listed on the WA DEC website as
Threatened Ecological Communities (TECs) endorsed in December 2006 (DEC, 2012a).
Table 1. Ecological community regional types listed in WA.
TEC name
Shrublands and woodlands on Perth to Gingin ironstone
Shrubland association on southern Swan Coastal Plain ironstone
(Bussleton area) (southern ironstone association)
Ferricrete floristic community (Rocky Springs type)
Scott River ironstone association
DEC community
identifier
NTHIRON
SCP10b
Ferricrete
SCOTT
IRONSTONE
WA status
Critically
Endangered
Critically
Endangered
Vulnerable
Endangered
One component is listed on the WA DEC website as Priority 1 for assessment as a threatened
ecological community (DEC, 2012b).

Wet ironstone heath community (Albany district)
There has been do endorsement of TECs for listing in WA since 2006. There is currently no
legislation covering the conservation of TECs in WA. However, informal non-statutory
processes are in place.
Relationships to other vegetation classifications
The ecological community falls within the National Vegetation Information System (NVIS)
equivalents of:

Major vegetation group 17 Other shrublands
19

Major vegetation group 18 Heathlands
Differences to similar or intergrading ecological communities
Kalbarri ironstone community
This plant community is located near Kalbarri in the north of the Geraldton Sand Plains
bioregion and is surrounded by sandplain. It is listed as a Priority 1 Ecological Community by
WA. The vegetation is dominated by mallee and/or Melaleuca spp. with an herbaceous
understorey (DEC, 2012b).
This ecological community may be part of the listed plant communities on ferricrete/ironstone,
however very little is known about it and there is no available data to determine whether it
meets the Description, Key Diagnostics and Condition Thresholds set out in Part A.
Shrublands and woodlands of banded ironstone formations in the Yilgarn Craton
The banded ironstone formations are found in the Yilgarn Craton in the Midwest and
Goldfields regions of WA. The plant communities associated with them are highly variable in
terms of floristics, containing many endemic species. A number of ecological communities
associated with banded ironstone formations are listed as Threatened or Priority 1 by WA
(DEC 2012a,b).
The formation of the ironstone in these ranges is a different process to that of the substrate of
the plant communities on ferricrete/ironstone. The banded ironstone formations are found on
the edge of the Southwest Botanic Province and extend into the more arid interior of WA.
Therefore rainfall is lower and winter inundation does not occur to the extent that it does in
south-west WA.
Assemblages of organic mound springs of the three springs area
This ecological community is found in conjunction with the ferricrete floristic community
regional type near Enabba. It is listed as an endangered Threatened Ecological Community by
WA. The ecological community consists of raised areas of peat formed and fed by continuous
discharge of groundwater (Rees and Broun, 2005). The peat provides a permanently moist
environment which supports a diversity of invertebrate fauna (Rees and Broun, 2005).
Level of protection in reserves
Based on information contained in interim recovery plans, just over half (52%) of the
ecological community is currently protected in some form of conservation reserve (HamiltonBrown et al., 2004; Luu and English, 2004; Meissner and English, 2005a,b; DEC, 2012c).
20
Appendix D - Description of threats
Threats to the ecological community vary across the regional types and occurrences. The
biggest threats are clearing and dieback disease caused by Phytophthora cinnamomi. The
ecological community occurs as isolated patches and is therefore subject to threats from
grazing and weed invasion. Threats which have the potential to significantly impact the
ecological community are altered fire regimes, changes to hydrological regimes and climate
change.
Clearing
The ecological community occurs in the south-west of WA, where the main cause of habitat
loss has been agricultural expansion (Conservation International, 2007). The plant communities
which make up the ecological community are naturally restricted in the landscape due to the
restricted nature of the substrate. However, clearing has occurred in the past and remains a
threat. The shallow soils associated with the ferricrete/ironstone are not ideal for agriculture as
it is hard for many crop species to establish. Therefore the vegetation on deeper soils
surrounding the plant communities has been more extensively cleared. However in many cases,
the plant communities have been removed and the ironstone substrate dug up to allow more
suitable plant species for grazing and cropping to grow. Where the substrate has been removed,
the ecological community is irretrievable. The regional types which have suffered the greatest
loss in extent since European occupation are those that are in the agricultural districts north and
south of Perth. The Perth to Gingin ironstone association regional type has suffered a 94-98%
loss (DEC, 2012c) and the Shrublands on southern Swan Coastal Plain ironstone near
Busselton have suffered an 86-89% loss (Meissner and English, 2005a) in extent since
European occupation.
Where patches of the ecological community have not been cleared, they generally occur as
isolated patches within a cleared landscape. These patches are therefore subject to a range of
associated threatening process including increased runoff, weed invasion, grazing and changes
in hydrological regimes.
Dieback disease
This disease is caused by the pathogen Phytophthora cinnamomi, a water mould which was
inadvertently introduced from south-east Asia and impacts a number of native flora across
Australia. Propagules are spread over large distances through root systems, movement of
people and vehicles which have come into contact with infested soil, and in water flowing in
surface and near-surface drainage systems (Shearer et al., 2007). WA is thought to be the most
impacted state due to favourable climate, soil and susceptible plant species (dieback.org.au,
2012). It is estimated that 800 plant species in the south-west of WA, including the families
Proteaceae and Epacridaceae, are highly susceptible to the disease (Lu and English, 2004;
Shearer et al., 2004).
Three out of the five regional types are known to be impacted by this pathogen. The Perth to
Gingin ironstone association is not believed to be susceptible as there are very few dieback
indicator species present (Meissner and English, 2005b). There is no information on the
susceptibility of the Wet ironstone heath community (Albany district), although as it contains
plants from the Proteaceae and Epacridaceae families it is likely to be susceptible. The regional
types that are impacted by dieback are seriously threatened by the disease. These communities
contain a high proportion of susceptible species from the Proteaceae and Epacridaceae families.
The disease causes the plant roots to rot, resulting in death from drought stress (HamiltonBrown et al., 2004). Rare species such as the endangered Banksia nivea subsp. uliginosa
(swamp honeypot) are highly susceptible (Meissner and English, 2005a). Dieback disease has
the potential to significantly impact on the ecological community through loss of plant species
21
and changes in community structure. Loss of plant species is also likely to increase the chance
of weed invasion which would lead to further impacts on the ecological community.
Grazing
Grazing is known to impact on all regional types of the ecological community. Remaining
patches are subject to varying degrees of grazing by both native and non-native species. As
many patches are isolated in agricultural landscapes, they are currently being grazed or have
been grazed in the past by sheep (Ovis aries) and cattle (Bos taurus). Many patches are also
grazed by Macropus rufus (red kangaroo) and rabbits (Oryctolagus cuniculus). Kangaroos have
a large impact on vegetation through grazing, as well as trampling and breaking foliage (Luu
and English, 2004). Grazing in areas of the ecological community can assist weed invasion
through soil disturbance, altered soil fertility and spread of weed propagules. Preferential
browsing of the understorey, particularly on herbaceous species, may impact the structure and
diversity of the ecological community.
In the Scott River ironstone association regional type the species composition has been altered
by selective grazing of edible species, introduction of weeds and nutrients and trampling (Luu
and English 2004). This is also the case in the Perth to Gingin ironstone association and
Shrubland on southern Swan Coastal Plain regional types (Meissner and English, 2005a,b).
Grazing is thought to have caused an increase in weed species such as capeweed (Arctotheca
calendula), ursinia weed (Ursinia anthemoides), silvergrasses (Vulpia spp.), onion grass
(Romulea rosea) and big quaking grass (Briza major) (Meissner and English, 2005b). In the
Ferricrete floristic community regional type, grazing by rabbits is thought to have caused an
increase in nutrient levels from droppings leading to introduction of weed species (HamiltonBrown et al., 2004).
Weeds
The extent and impact of weed invasion is variable across the ecological community due to
differences in the level of disturbance and surrounding landscape use. Weed invasions are
usually assisted by disturbance to the soil, along with increased soil fertility. If weed
propagules are present in a patch then fire, grazing, nutrient enrichment, mowing and spraying
of chemicals can all predispose areas to weed invasion. The creation of tracks through patches
of the ecological community is known to facilitate weed spread (Lu and English, 2004;
Meissner and English, 2005a). When weeds are present in the ecological community they have
significant impacts through competition with native species, by competing for soil moisture,
nutrients and light. The presence of weed species can also lead to altered fire regimes through
easy ignition of high fuel loads produced by annuals and may assist the spread of dieback
disease (Phytophthera cinnamomi) (Luu and English, 2004).
In the Perth to Gingin ironstone association regional type the following exotic species are
common: onion grass (Romulea rosea), quaking grass (Briza maxima), suckling clover
(Trifolium dubium), corn spurr (Spergula arvensis) and hesperantha (Hesperanthura falcata)
(Meissner and English, 2005b). Weed species have severely degraded the remaining
occurrences of this regional type (Meissner and English, 2005b).
Inappropriate fire regimes
The fire regime requirements of the ecological community are not fully understood, however,
the impact of too frequent fires or exclusion of fire can be deduced. Impacts from altered fire
regimes are noted in the Interim Recovery Plans for four of the regional types (HamiltonBrown et al 2004; Luu and English, 2004; Meissner and English, 2005 a,b). Many plant species
in the ecological community are obligate-seeding, which means they require heat from fires for
their seeds to germinate. If fires are too frequent, there will not be enough time for these plants
to flower and set seed. Alternatively, if the time between fires is too long, these plants may
22
senesce and be unable to reproduce. The disturbance created by fire can create niche gaps
which allow weed species to become established. Some weeds (e.g. grasses) are highly
flammable and can increase the intensity and frequency of fires.
Hydrological changes
A potential threat to the functional integrity of the ecological community is a change in
hydrological regimes. A defining characteristic of the ecological community is seasonal
inundation from winter rainfall and groundwater. Changes to the regular hydrological regime
could therefore have a significant impact. A number of occurrences are located on the boundary
of areas that are highly cleared which can lead to increases in surface flow and groundwater
recharge (Meissner and English, 2005a). Alternatively, abstraction from irrigation bores and
from sand mining operations may lower groundwater levels. Changes to groundwater levels
may also lead to salt accumulating near the surface (Luu and English, 2004).
Changes to the period or depth of ponding could affect structure and composition through
changes in the timing of growth of annuals which could then favour different plant species
including weeds (Luu and English, 2004; Meissner and English, 2005a,b). Plant species in the
ecological community, which are adapted to fresh water inundation, are unlikely to be able to
cope with increased saline or water-logged conditions (Hamilton-Brown et al., 2004).
Climate change
There has been an observed significant change in rainfall in south-west WA. A sharp drop in
rainfall occurred in south-west WA in the mid-1970s, with some of the driest years on record
occurring since 1975. This drop in rainfall was most apparent in late autumn and winter, with
fewer storms and less rainfall per storm. The driest winter on record was recorded in 2010
(Western Australia Climate Sciences Centre, 2010). South-west WA’s significant drying trend
is forecast to worsen under climate change. If current climate trends continue, there will be up
to 80 per cent more droughts in south-western WA by 2070 (Department of Climate Change,
2010).
As inundation following winter rainfall is a defining characteristic of this ecological
community, any changes to the timing or degree of rainfall is likely to have an impact through
altered species composition and structure. The annual herbs that rely on winter rainfall to
flower are unlikely to persist.
Key threatening processes
Key Threatening Processes are listed under the EPBC Act. A threatening process is defined as a
key threatening process if it threatens or may threaten the survival, abundance or evolutionary
development of a native species or ecological community.
Key Threatening Processes that operate in the ecological community include:



Competition and land degradation by rabbits
Dieback caused by root-rot fungus (Phytophthora cinnamomi)
Land clearing
23
Appendix E - Eligibility for listing against the EPBC Act criteria
Criterion 1: Decline in geographic distribution
Estimates of pre-European extent and current extent are based on information provided by DEC
(DEC, 2012c) and Meissner and English (2005a) and are presented in Table 1 below. The
figures have been calculated for each regional type that comprises the ecological community.
The Ferricrete floristic community is thought to be largely uncleared since pre-European times.
There is no pre-European extent data for the Wet ironstone heath community (Albany district).
However, the current extent is estimated at 53-75ha based on information provided by DEC
(2012c). For the purposes of this Criterion, it has been assumed that these regional types have
not declined in extent.
Table 1. Estimates of pre-European and current extent
Regional type
Pre-European
extent (ha)
Current total
area (ha)
Percentage
decline
Shrublands and woodlands on Perth to Gingin
ironstone (Perth to Gingin ironstone association) of
the Swan Coastal Plain
900-1500
27-51
94-98
Shrublands on southern Swan Coastal Plain
ironstones
1200
130-164
86-89
Ferricrete floristic community (Rocky Springs
type)
395-473
395-473
0-16
Scott River ironstone association
1100-1700
276-404
63-84
Wet ironstone heath community (Albany district)
53-75
53-75
0-29
3648-4948
881-1167
68-82
Total
Based on the available data, the ecological community has declined in extent from
approximately 3600-4900 to 900-1200ha. This represents a substantial decline in the order of
68-82%. It is important to note that some patches of the ecological community that are included
in the data above may not meet the condition thresholds, such as patches with a high degree of
disturbance, so the decline may actually be more than is estimated. As there is no accurate preEuropean extent data for the Ferricrete floristic community (Rocky Springs type) or the Wet
ironstone heath community (Albany district), the actual decline may be further still.
The ecological community appears to have undergone a substantial decline in geographic
distribution. Therefore the ecological community would meet the relevant elements of Criterion
1 to make it eligible for listing as vulnerable.
.
Criterion 2: Small geographic distribution coupled with demonstrable threat
This criterion aims to identify ecological communities that are geographically restricted to
some extent. Three indicative measures apply: 1) extent of occurrence (i.e. the total geographic
range of the ecological community); 2) area of occupancy (i.e. the area actually occupied by the
ecological community within its natural range); and 3) patch size distribution (an indicator of
the degree of fragmentation). It is recognised that an ecological community with a distribution
that is small, either naturally or that has become so through modification, has an inherently
higher risk of extinction if it continues to be subject to ongoing threats that may cause it to be
lost in the future.
24
The ecological community is subject to a range of demonstrable threats, as outlined in
Appendix D. Many of these threats will continue to operate, or even intensify and compound
each other, rather than diminish, particularly without further coordinated recovery and
management effort.
The ecological community occurs in highly restricted patches from Eneabba in the north, down
to Scott River in the south, and across to Albany in the east. This is a large area that covers the
south-west corner of WA. Therefore, the extent of occurrence exceeds the one million hectare
threshold for considering its geographic distribution to be limited.
The remaining area of occupancy for the ecological community is approximately 900-1200ha
as presented in Table 2 above. This is indicative of a restricted geographic distribution (i.e.
>10 000ha but <100 000ha), and the lower end of the estimate is indicative of a very restricted
geographic distribution. An analysis of patch size based on DEC data indicates that there are 59
patches of the ecological community remaining (DEC, 2012c). Of the patches remaining, 63%
are less than 10ha and 88% are less than 50ha (Table 2). The available patch size data indicate
a high degree of fragmentation across the range of the ecological community consistent with a
restricted geographic distribution (i.e. patch size is typically less than 100ha).
Table 2. Patch data for the ecological community
Patch size (ha)
<1
1 - 10
10 - 20
20-50
>50
Total
Number of patches
Percentage of total
patches
10
27
10
5
7
59
Cumulative percentage
17
46
17
8
12
100
17
63
80
88
100
100
The ecological community appears to have a very restricted geographic distribution, based on
the generally small and fragmented size distribution of patches. It appears that the demonstrable
ongoing threats detailed in Appendix D could cause the ecological community to become lost
in the near future. Therefore, the ecological community would meet the relevant elements of
Criterion 2 to make it eligible for listing as endangered under this criterion.
.
Criterion 3: Loss or decline of functionally important species
The ecological community has variable composition and it is not possible to identify a single
species or suite of species that has critical functions.
There is no information available to the assessment judge if the ecological community has
undergone a loss or decline in functionally important species. Therefore, as the ecological
would not have been demonstrated to meet any of the required elements of Criterion 3, it would
not be eligible for listing in any category under this Criterion.
Criterion 4: Reduction in ecological community integrity
There are a number of threatening processes that may lead to a reduction in the integrity of the
ecological community. Incursion of weeds could change the structure of the ecological
community and out-compete native species. In the occurrences near Gingin there are very
small, degraded patches which occur on road reserves (Meissner and English, 2005b). All of
these small patches are considered totally destroyed as they have been severely degraded by
weeds and there are few ironstone plant species left (Meissner and English, 2005b).
Dieback disease caused by root-rot fungus (Phytophthora cinnamomi) is known to have
infected patches of the ecological community near Busselton, Scott River and Eneabba. As
25
many of the plant species in the ecological community are susceptible to this fungus, it has the
potential to have a very severe impact on the integrity of the ecological community through
change in structure, function and species composition.
Hydrological regimes are important to the ecological community as they provide the conditions
in which the substrate is formed and maintained. They also influence species composition due
to wetting and drying cycles throughout the year. Changes to hydrological regimes and/or
increased salinity are likely to have a severe impact on the ecological community.
Weed incursion, dieback disease and changes to hydrological regimes all have the potential to
reduce the integrity of the ecological community by disruption of important community
processes and to degrade the ecological community.
However, there is not enough evidence to indicate that these factors are having an impact on
the whole of the ecological community. Therefore, as the ecological community would not
have been demonstrated to meet any of the required elements of Criterion 4, it would not be
eligible for listing in any category under this Criterion.
Criterion 5: Rate of continuing detrimental change
The ecological community is suspected to be undergoing continuing detrimental change
(through clearing, weed incursions, grazing and changes to hydrological regimes) over the
immediate past.
However, there are no data available to the assessment to judge the rate of continuing
detrimental change experienced by the ecological community. Therefore, as the ecological
community would not have been demonstrated to meet any of the required elements of
Criterion 5, it would not be eligible for listing in any category under this Criterion.
Criterion 6: Quantitative analysis showing probability of extinction
There is no quantitative data available to assess this ecological community under this criterion.
Therefore, it would not be eligible for listing under this criterion.
There is no quantitative data available to the assessment to evaluate this ecological community
under this criterion. Therefore, it would not be eligible for listing under this criterion.
26
PART D
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