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Interim Recovery Plan No. 354
Clay pans of the Swan Coastal Plain
(Community types 7, 8, 9 and 10a - Gibson et al. 1994 and Clay pans with mid dense
shrublands of Melaleuca lateritia over herbs)
2015-2020
October 2015
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Foreword
Interim Recovery Plans (IRPs) are developed within the framework laid down in Department of Parks and Wildlife
Policy Statements Nos. 44 and 50.
IRPs outline the recovery actions that are required to urgently address those threatening processes most
affecting the ongoing survival of threatened taxa or ecological communities, and begin the recovery process.
The department is committed to ensuring that threatened ecological communities are conserved through the
preparation and implementation of Recovery Plans or Interim Recovery Plans and by ensuring that conservation
action commences as soon as possible and always within one year of endorsement of that rank by the
department’s Director of Science and Conservation.
This IRP will operate from October 2015 but will remain in force until withdrawn or replaced. It is intended that, if
the ecological communities are still ranked Vulnerable or Endangered after five years, this Recovery Plan will be
replaced or updated.
This IRP was approved by the Director of Science and Conservation on 14 October 2015. The provision of funds
identified in this IRP is dependent on budgetary and other constraints affecting the department, as well as the
need to address other priorities.
Information in this IRP was accurate as at September 2015.
ACKNOWLEDGEMENTS
This plan was prepared by Valerie English. Cover photograph by Valerie English.
The following people provided valuable advice and assistance in the preparation of this Interim Recovery Plan:
Kate Brown
Parks and Wildlife, Swan Region
Andrew Webb
Parks and Wildlife, South West Region
Anne Harris
Parks and Wildlife, Swan Coastal District
Ben Lullfitz
Parks and Wildlife, Busselton District
Marie Edgley
Parks and Wildlife, Wheatbelt Region
Adam Turnbull
Parks and Wildlife, Species and Communities Branch
Cathy Bourke
Parks and Wildlife, Perth Hills District
Ken Atkins
Parks and Wildlife, Kensington
Jason Wiktotwicz
Curtin University student
Brett Beecham
Parks and Wildlife, Wheatbelt Region
Bob Huston
Parks and Wildlife, Perth Hills District
Deanna Rasmussen
Parks and Wildlife, Moora District
CITATION
This Interim Recovery Plan should be cited as:
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Department of Parks and Wildlife (2015). Interim Recovery Plan 2015-2020 for Clay pans of the Swan Coastal
Plain (Swan Coastal Plain community types 7, 8, 9 and 10a) and Clay pans with mid dense shrublands of
Melaleuca lateritia over herbs. Interim Recovery Plan No. 354. Perth.
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SUMMARY
Name: This plan encompasses the clay pans of the Swan Coastal Plain that includes the following four Western
Australia listed threatened ecological communities (TECs):
Herb rich saline shrublands in clay pans (Swan Coastal Plain community type 7 as identified in Gibson et
al. 1994 (SCP07))
Herb rich shrublands in clay pans (SCP08 – Swan Coastal Plain community type 8)
Dense shrublands on clay flats (SCP09 – Swan Coastal Plain Community type 9)
Shrublands on dry clay flats (SCP10a – Swan Coastal Plain Community type 10a)
The plan also covers the ‘Clay pans with mid dense shrublands of Melaleuca lateritia over herbs’ (hereafter
termed the ‘Clay pans with shrubs over herbs’) that is ranked Priority 1 in Western Australia.
These four TECs and one PEC comprise the ‘Clay pans of the Swan Coastal Plain’ that is listed as a critically
endangered TEC under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC
Act). There are 114 occurrences of the five clay pan communities that cover a total of about 909 ha.
Description: The clay pan communities occur where clay substrate is low in the landscape and forms an
impermeable layer close to the surface. These wetlands that rely on rainfall and local surface drainage to fill are
considered unlikely to be connected to groundwater. The clay pans then dry out to form a relatively impervious
substrate in summer. A suite of
perennial plants that propagate by underground bulbs, tubers or corms
(geophytes), and annual herbs flower sequentially as the clay pans dry out. The clay pans are the most diverse of
the Swan Coastal Plain wetlands and contain a number of local endemic flora.
Department of Parks and Wildlife Regions: Swan, South West, Midwest and Wheatbelt
Department of Parks and Wildlife Districts: Swan Coastal, Perth Hills, Wellington, Blackwood, and Moora
Districts.
Local Government Authorities: Serpentine–Jarrahdale, Harvey, Murray, Armadale, Gosnells, Swan, Waroona,
Gingin, Beverley, Bunbury, Busselton, Capel, Dardanup, Kalamunda, Boyup Brook, Toodyay and Kojonup.
Conservation status: Community types 7, 8 and 9 were endorsed by the WA Minister for Environment in
November 2001 as Vulnerable, and community type 10a as Endangered. Clay pans with mid dense shrublands of
Melaleuca lateritia over herbs was ranked Priority 1 in Western Australia in May 2006. The umbrella type ‘Clay
pans of the Swan Coastal Plain’ was listed as Endangered under EPBC Act in March 2012.
Habitat requirements: These communities typically occur on clay soils in low lying flats that are seasonally wet
or inundated.
Habitat critical to survival: The critical habitat for this community is the clay soils on which the community
occurs, and the fresh surface water that helps to sustain key species in this community, and the catchment for
this surface water.
The habitat critical to survival is: The area of occupancy of known occurrences; similar habitat adjacent to
important occurrences (i.e. within approximately 200m), i.e. poorly drained flats, depressions or winter wet clay
flats; remnant vegetation that surrounds or links several occurrences (this is to provide habitat for pollinators or
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to allow them to move between occurrences); and the local catchment for the surface and potentially
groundwater that maintains the winter-wet habitat of the communities (these clay pan communities would be
dependent on maintenance of the local hydrological conditions).
Important occurrences: Occurrences that provide for representation of the community across its geographic
range and that can be managed for conservation and/or with conservation included in their purpose are
considered important occurrences of this community. Occurrences within conservation reserves and Bush
Forever sites, and occurrences with comparatively large intact areas of the community that are in relatively good
condition outside of Bush Forever, are considered important occurrences.
Affected interests: Land owners and managers of all occurrences may be affected by actions in this plan, in
particular on those lands not managed by Parks and Wildlife or intended to be transferred to the department’s
management. Occurrences are within the Shires of Armadale, Busselton, Boyup Brook, Capel, Gosnells, Murray,
Serpentine-Jarrahdale, Swan, Waroona, Gingin, Bunbury, Capel, Dardanup, Kalamunda, Toodyay and Kojonup.
They occur on land managed by Main Roads WA, Parks and Wildlife, Water Corporation, University of WA, WA
Planning Commission, local governments, and on private land.
Indigenous interests: An Aboriginal Sites Register is kept by the Department of Indigenous Affairs, and lists one
Artifact/Scatter site and a Ceremonial and Morphological site within the vicinity of the occurrences. The South
West Aboriginal Land and Sea Council (SWALSC), an umbrella group, covers the areas considered in this plan.
Appendix 1 identifies areas of the ecological community that contain sites that are known to have particular
aboriginal significance. Actions identify the intention to continue liaison with relevant groups, including
indigenous groups.
Social and economic impacts and benefits: The implementation of this recovery plan has the potential to have
some social and economic impact, where occurrences are located on lands not specifically managed for
conservation, such as road reserves and private property. Recovery actions refer to continued liaison between
stakeholders with regard to these areas. Negotiations will continue with land managers with respect to the future
management of occurrences not in conservation estate.
Related biodiversity impacts and benefits: Thirteen other TECs co-occur within remnant vegetation that
contains the clay pan communities, and will benefit from their management.
Twelve declared rare flora (DRF) are known from the clay pan communities: Calytrix breviseta subsp. breviseta,
Verticordia plumosa var. vassensis, Verticordia densiflora var. pedunculata, Chamelaucium sp. S Coastal Plain
(previously Chamelaucium roycei ms), Diuris purdiei, Grevillea curviloba subsp. incurva, Lepidosperma rostratum,
Ptilotus pyramidatus, Synaphea stenoloba, Trithuria occidentalis, Eleocharis keigheryi and Synaphea sp. Fairbridge
Farm; and 42 priority flora taxa also occur in the communities. Recovery actions implemented to improve the
quality or security of the community are also likely to improve the status of component species.
There are three critically endangered fauna known to be dependent on clay pans and the surrounding
communities for a portion of their life/breeding cycle. These are Pseudemydura umbrina (Western Swamp
Tortoise) and two native bees: Leioproctus douglasiellus and Neopasiphae simplicior.
Term of plan: The plan will operate from 2015 to 2020 but will remain in force until withdrawn or replaced. It is
intended that, if the ecological communities are still ranked vulnerable or endangered in Western Australia after
five years, the need for further recovery actions and the need for an updated recovery plan will be evaluated.
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IRP Objective(s): To maintain or improve the overall condition of the clay pan communities and reduce the level
of threat.
Criteria for success:
90% or more of the aerial extent of occurrences of each clay pan type covered by this recovery plan
maintained at the same condition rank, or improved (Bush Forever condition scales) over the life of the
plan, excluding effects of drying climate that are outside the scope of this plan.
An increase in the number of occurrences of the clay pan types managed for conservation and/or with
conservation included in the purpose.
Representative areas of the clay pan types across their geographical range maintained in the same or
improved condition (Bush Forever condition scales).
Criteria for failure:
Decline in condition rank to a lower category (Bush Forever condition scales) of 10% or more of the total
aerial extent of the sub-communities covered by this plan, excluding effects of drying climate that are
outside the scope of this plan.
Failure to achieve an increase in the area managed for conservation for the communities covered by this
plan.
Summary of Recovery Actions:
Liaise with stakeholders to implement recovery
Identify potential new occurrences
Monitor extent and boundaries of occurrences
Map habitat critical to survival
Encompass monitoring in an adaptive management
framework
Seek to minimise direct clearing and hydrological
change
Develop and implement fire management strategy
Implement disease hygiene procedures
Implement weed control
Seek long term protection for conservation
Investigate, monitor and manage water quality and
hydrology
Ensure best practice land management in areas of
competing interests
Implement and monitor control of feral and grazing
animals
Develop management guidelines
Protect clay pans from physical damage
Report on recovery plan implementation
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1.
BACKGROUND
1.1
History, defining characteristics and conservation significance
The clay pan basins and clay flats of south western Australia are collectively termed clay pans, and occur where
clay soils form an impermeable layer close to the surface. Wetlands in clay pans rely on rainfall and surface
runoff to fill and are probably not connected to groundwater. These wetlands contain a rich suite of geophytes
and annual species that flower at different times as the clay pans dry towards summer. The clay pans are the
most diverse of the Swan Coastal Plain wetlands and contain high numbers of local endemics. There are no
specific suites of flora that characterise all the clay pans, but they share general characteristics of substrate,
landform, hydrology and vegetation structure. They also all meet Keeley and Zedler’s (1998) definition of vernal
pools; ‘precipitation-filled seasonal wetlands inundated during periods when temperature is sufficient for plant
growth, followed by a brief waterlogged-terrestrial stage and culminating in extreme desiccating soil conditions
of extended duration.’
The clay pans are comprised of reasonably productive agricultural soils and many were cleared and drained soon
after European settlement. Other areas were mined for clay for brick and tile manufacture. Remnant vegetation
in clay pans was largely on the Swan Coastal Plain close to metropolitan Perth including in some areas that have
been cleared more recently for urban development.
Gibson et al. (1994) defined a series of floristic community types across the southern Swan Coastal Plain based
on analysis of 509 quadrats. This included four units that occurred on clay substrates, and that varied in floristic
composition due to a suite of factors including substrate and rainfall. These are:
Herb rich saline shrublands in clay pans (Swan Coastal Plain community type 7 as identified in Gibson et
al. 1994 (SCP07))
Herb rich shrublands in clay pans (SCP08 – Swan Coastal Plain community type 8)
Dense shrublands on clay flats (SCP09 – Swan Coastal Plain Community type 9)
Shrublands on dry clay flats (SCP10a – Swan Coastal Plain Community type 10a)
All of these clay pan types were listed as threatened ecological communities (TECs) in Western Australia in the
1990s.
Data for the vegetation of the seasonal clay-based wetlands across the extent of south western Australia were
analysed by Gibson et al. (2005) and vegetation units were identified based on floristic patterning. An additional
clay pan type named ‘Clay pans with mid dense shrublands of Melaleuca lateritia over herbs’ was identified
through the analysis, and was included on the Priority ecological community list for Western Australia in 2006. In
2012 the four clay pan types identified by Gibson et al. (1994) and the ‘Clay pans with mid dense shrublands of
Melaleuca lateritia over herbs’ were listed as a critically endangered community under the EPBC Act, under the
umbrella title ‘Clay pans of the Swan Coastal Plain’.
There are 114 occurrences of the clay pan communities in 50 separate locations that occupy a total of about 909
ha. The communities are highly fragmented, with about 60% of occurrences under 10 ha in size.
The clay pan
communities occur in significant bushland including Ellenbrook, Forrestdale Lake, Moore River, Byrd Swamp,
Austin Bay, Drummond and Kooljerrenup Nature Reserves;
Wandoo National Park, the Greater Brixton Street
Wetlands, Anstey-Keane damplands, Jandakot Regional Park, and Brickwood Reserve (See Appendix 1, 3).
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A summary of total areas in land management categories for the clay pan types occurs in Table 1.
Table 1: Land management categories for clay pan communities
Community
Conservation
reserves (ha)
Other state, local
government
reserves (eg road,
rail, recreation
etc) (ha)
C’mwealth
lands (ha)
Private
lands (ha)
Bush
Forever
(ha)
Total (ha)
SCP 07
124.6
70
7.1
14.4
35.9
216.1
SCP08
116.6
168.5
0.1
12.9
127.3
298.1
SCP09
195.4
23.1
0
0
3.4
218.5
SCP10a
24.8
62.9
0
5
35.4
92.7
Clay pans with
shrubs over
herbs
82.9
1.2
0
0
0
84.1
Total (ha)
544.3
325.7
7.2
32.3
202
909.5
A
reas of the clay pans are listed as Wetlands of National Significance, including Brixton Street Wetlands, Ellen
Brook swamp systems, and Forrestdale Lake Nature Reserve which is also a Ramsar site (Environment Australia,
2001). The threatened and priority flora that occur in the clay pan communities are listed in Table 2. Some of the
clay pan sites were identified through surveys completed for Bush Forever, and some also occur in Bush Forever
sites (Keighery et al. 2012; Government of Western Australia 2000; see Appendix 1). The aim of Bush Forever is to
seek to protect listed sites through a specified planning process.
A suite of fauna depend on the vegetation and surface water habitat, and seasonal changes in the clay pans
communities. Three species listed under the EPBC Act are dependent on clay pans and adjacent areas. These are
the critically endangered western swamp tortoise (Pseudemydura umbrina), and two species of native bee;
Leioproctus douglasiellus (endangered) and Neopasiphae simplicior (critically endangered).
Appendix 1 provides a summary of information about the occurrences including land tenure, extent, soils and
condition.
1.2
Biological and ecological characteristics
Seasonal wetlands occur on the clay flats as the clay impedes water movement horizontally and vertically.
Rainfall therefore collects on the surface and soils become waterlogged. These wetlands tend to dry soon after
the rain stops in the late spring and early summer.
The hydrology is the main driver of the ecological functions of the assemblages that occur in clay pans.
Variations in depth and timing of inundation have a major influence over the suites of flora that occur in a
particular location and this explains some of the variation in the community’s composition across its extent.
Changes in hydrological status will significantly alter the assemblages in the communities. More than 90% of the
clay pan communities have been lost through clearing and drainage of their habitat since European settlement.
Much of the high species richness arises from geophytes and annual flora that flower sequentially as the clay
pans dry. Perennial shrubs and herbs contribute less to total species richness (Gibson et al. 2005). The shrubs in
clay pans may appear stressed or dead over summer with leaves yellowing, but can recover when water is again
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added to the system.
The clay pans contain a rich and variable flora including a series of wetland genera that are widespread such as
Isoetes, Myriophyllum, Cotula and Eryngium and a suite that are characteristic of southern Australia including
Stylidium, Tribonanthes, Drosera and Centrolepis. The clay pans also include a series of terrestrial taxa (Gibson et
al. 2005).
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