South Coast NRM Biodiversity Inventory Program
Regional Salinity Hazard Assessment
on Priority Biodiversity Assets
Biodiversity Assets in Fitzgerald National Park
June 2008
Acknowledgements
This salinity hazard assessment report has been prepared by Deon Utber and Janet Newell,
Department of Environment and Conservation (DEC), on behalf of the South Coast NRM Inc.
as part of the Biodiversity Inventory Program. The salinity hazard data analysis was conducted
by Naeim Babaii, Geographic Information Services, Department of Environment and
Conservation using ArcMap 9.1.
The following people provided assistance and advice in the preparation of this report:
Ruhi Ferdowsian, John Simons
Tilo Massenbauer
Graeme Behn, Shane French, Katherine
Zdunic
Department of Agriculture
Esperance, DEC
GIS section, DEC
Species and Communities Branch, DEC
Table of Contents
SUMMARY............................................................................................................................................. I
INTRODUCTION ..................................................................................................................................1
BACKGROUND.....................................................................................................................................1
DRYLAND SALINITY .............................................................................................................................1
HAZARD V’S RISK.................................................................................................................................1
PRIORITY BIODIVERSITY ASSETS OF THE SOUTH COAST NRM REGION ...............................................2
PREVIOUS SALINITY MAPPING .............................................................................................................3
National Land and Water Resource Audit ......................................................................................3
Land Monitor ..................................................................................................................................4
Rapid Catchment Appraisal ............................................................................................................4
SALINITY INVESTMENT FRAMEWORK ...................................................................................................4
METHODS..............................................................................................................................................5
STUDY LOCATION.................................................................................................................................5
DATA SETS ...........................................................................................................................................5
DATA ANALYSIS...................................................................................................................................6
SALINITY HAZARD BIODIVERSITY SCORE ............................................................................................6
RESULTS AND DISCUSSION.............................................................................................................6
THREATENED FAUNA ...........................................................................................................................6
THREATENED FLORA ............................................................................................................................7
THREATENED ECOLOGICAL COMMUNITIES ..........................................................................................9
REMNANT VEGETATION .....................................................................................................................10
SALINITY HAZARD BIODIVERSITY SCORE ..........................................................................................13
CONSTRAINTS AND ISSUES..................................................................................................................14
RECOMMENDATIONS .....................................................................................................................15
REFERENCES .....................................................................................................................................17
APPENDIX 1 ........................................................................................................................................19
Summary
Dryland salinity is a major threatening process in the South Coast NRM region. The causes of
salinity and the impacts on agriculture are relatively well understood, but until recent years
there has been limited focus on how salinity may affect the health of native plants, vegetation
communities or interrelated ecosystem processes (Cramer and Hobbs 2002). The South Coast
NRM Inc. therefore identified a need to assess the potential impacts of salinity on priority
biodiversity assets of the region.
This report assesses salinity threat for occurrences of the South Coast NRM regions
biodiversity assets using existing regional scale datasets. This report is an assessment of
salinity hazard (has the potential to cause harm to an asset), rather than salinity risk (the
chance that a hazard will cause harm to an asset). This hazard assessment identifies the
biodiversity assets and catchments at a regional scale for which further research should be
focused in order to determine salinity risk.
This salinity hazard assessment found that salinity would probably not be a major threat for
most threatened fauna species on the South Coast. However, salinity would have the greatest
potential to impact aquatic species (e.g. Balston’s Pygmy Perch, Western Trout Minnow,
Western Mud Minnow, Black-stripe Minnow and the Sunset Frog) or species which rely on
water ecosystems (e.g. Water-rat).
Eight threatened flora species were determined to be at most hazard from salinity as over 50%
of their known locations are at hazard. All the records of two species, Apodasmia ceramophila
and Stachystemon vinosus, are located in the salinity hazard area.
Nearly all of the Herblands and Bunch Grasslands TEC was determined to be at hazard from
salinity. Therefore, salinity has the potential to be a major threatening process for this TEC.
The Ironstone heath and Banksia Coccinea thicket PEC were also found to have high potential
hazard from salinity.
A salinity hazard biodiversity score identified the Irwin Inlet_Kent_Bow catchment as the
catchment within which the greatest numbers of biodiversity assets were at hazard from
salinity. Therefore it is recommended priority should be given to this catchment, and others
that had a high score, for salinity risk mapping to identify the risk of salinity on biodiversity
assets.
This salinity hazard mapping project has identified the biodiversity assets (threatened fauna,
flora and ecological communities) that are at most hazard from salinity. Research into the
susceptibility of the identified biodiversity assets to salinity and the potential impacts of salinity
to habitat should be made a priority.
The results of this project are intended as only a guide to identifying priority biodiversity assets
and catchments in the South Coast NRM region for which further research into the risk and
impacts of salinity should be conducted. These results do not identify the degree to which the
assets would be affected by salinity.
i
ii
Introduction
The South Coast NRM region, covering over 9.7 million hectares, is part of the internationally
recognized southwest Western Australia biodiversity ‘hotspot’ due to its high species diversity,
number of endemic species and the level of risk from loss of habitat.
Dryland salinity is a major threatening process in the South Coast region. The causes of
salinity and its impacts on agriculture are relatively well understood, but until recent years there
has been limited focus on how salinity may affect the health of native plants, vegetation
communities or interrelated ecosystem processes (Cramer and Hobbs 2002).
South Coast NRM Inc. identified a need to assess the potential impacts of salinity on priority
biodiversity assets for the South Coast NRM region. This project assesses salinity threat for
occurrences of these priority biodiversity assets using existing regional scale datasets, in order
to identify assets for which further research should be focused.
The concept for this project was to develop a salinity risk map for biodiversity assets. In
interpreting how this would be achieve the project staff sought advice from several experts who
have had extensive experience in either salinity risk mapping or prioritisation of assets at risk
from salinity. Examples of salinity assessment from the Kent River area and the Salinity
Investment Framework made it apparent that this project did not have the resources to
undertake an extensive salinity risk mapping exercise. The approach decided upon was a
much simpler one that assessed the salinity hazard rather than risk to specific biodiversity
assets that occurred within the 0.5 meter height above valley floor.
Background
Dryland Salinity
The WA State of Environment Report (Environment Protection Authority 2007) identified land
salinisation, salinisation of inland waters, and maintenance of biodiversity as three of the
highest priority environmental issues in Western Australia. The WA Salinity Action Plan 1996
reported that over 70% of Australia’s dryland salinity could be found in WA, with an estimated
1.8 million ha already salt-affected, and that this area could double in the next 15 to 25 years,
and then double again before reaching equilibrium (Caccetta et al. 2000).
Dryland salinity results from the clearing of deep-rooted perennial vegetation and its
replacement with annual crops with relatively shallow roots which do not dry out the soil profile
as deeply, resulting in a rising water table. As a consequence, salt stored in the soil above
previous water tables dissolves and rises to the surface, causing, along with water-logging, the
death of vegetation (George et al. 1995; Spies and Woodgate 2005).
Hazard v’s Risk
Hazard refers to anything that can potentially cause harm to an asset (Spies and Woodgate
2005). Salt becomes a hazard when it has the potential to move into a position where it has
the ability to threaten as asset. A dryland salinity hazard results from the combination of salt
and the potential for movement by surface or groundwater.
1
Risk is the change that a hazard will cause harm to an asset at some defined time in the future
(Spies and Woodgate 2005). Risk is classically defined as an adverse impact multiplied by its
likelihood of occurrence at some given time in the future. Risk implies a prediction about the
severity of the damage and when it will occur.
Priority Biodiversity Assets of the South Coast NRM Region
The South Coast NRM region contains 4687 known flora taxa (ie. species and subspecies),
around 400 of which are endemic to the region, 42 mammal, 270 bird, 22 frog and 70 reptile
species (Danks 2004). Around 120 vegetation associations, as described and mapped by John
Beard, are represented in the region, including forests, woodlands, mallee, mallee-heath and
shrublands.
For this salinity mapping project priority biodiversity assets have been defined as the flora,
fauna and ecological communities that are at risk of extinction unless effective remedial action
is taken and are included by the Department of Environment and Conservation in the lists of
the State’s threatened species and ecological communities. The priority biodiversity assets of
the South Coast NRM region are summarised in Table 1.
Table 1: The priority biodiversity assets that occur in the South Coast NRM region, including the
threatened (CE – critically endangered, EN – endangered, VU – vulnerable) and priority fauna, flora and
ecological communities. Data current to April 2008 (Species and Communities Branch, Department of
Environment and Conservation).
Fauna
Flora
Ecological
Communities
CE
EN
VU
Total
Threatened
Priority
3
11
20
34
37
31
40
56
127
779
2
1
3
6
20
Threatened species and communities are grouped into categories of risk according to
internationally accepted IUCN criteria (Danks 2004). The most seriously endangered are
placed in the Critically Endangered category followed by the Endangered and Vulnerable
categories. Extinct (or presumed Extinct) species are also listed as such. Species and
communities for which there is some concern about their conservation status, or which are too
poorly known for assessment as well as those only recently removed from the list due to
conservation action, are listed separately as Priority Species.
The first three Priority categories (Priorities 1, 2 or 3) are ranked in order of priority for survey
and evaluation of their conservation status so that consideration can be given to their
declaration as threatened flora or fauna (Danks 2004). Species that have been adequately
surveyed, are rare but not threatened, or meet criteria for Near Threatened, or that have been
recently removed from the threatened list for other than taxonomic reasons, are placed in
Priority 4. These species require regular monitoring. Conservation Dependent species are
also placed in Priority 4.
2
Previous Salinity Mapping
National Land and Water Resource Audit
The current extent of dryland salinity and predictions of future risk over the south west
agricultural areas of Western Australia has been mapped using two separate methods based
on (a) groundwater depth and trends (Short and McConnell 2000) and (b) DEMs (the National
Dryland Salinity Program (Land Monitor Program)). This area includes most of the south coast
NRM region but not all.
As part of the National Land and Water Resource Audit (NLWRA) Short and McConnell (2000)
mapped the current extent of salinity, predictions of future risk and impacts on social, economic
and biological factors at a regional scale over the south-west agricultural zone.
Short and McConnell (2000) used the Natural Resource Assessment Group (NRAG) within
Agriculture WA soil-landscape system to determine the spatial units. Groundwater depth and
trends in change of depth were used to determine the salinity risk. As the spatial location of
bores used by the Agriculture WA Catchment Hydrology Group to monitor water depth are
highly variable, with some areas with limited bores, the reliability of the salinity risk analysis is
variable over the region. This risk allocation is at a regional context, mapped at between 1:50
000 and 1: 100 000, and therefore the risk allocation is not suitable for extrapolation to the
catchment or farm scale. (Short and McConnell 2000).
The key results of this NLWRA salinity risk analysis for the south west region include (Short
and McConnell 2000):
- Groundwater trends are dominated by rising or stable trends. No land systems have
significant falling trends.
- Approximately 16% of the south west region had the potential for salinity in 2000 due to
shallow watertables, and predicted to increase to approximately 33% of the region (approx.
6.5 million hectares) by 2050.
- Surface water resources are likely to become more saline.
- Twenty-one of the 54 wetlands located within the region are potentially at risk of shallow
watertables, which may affect wetland health.
- In 2000 nearly 600,000 ha of perennial vegetation was estimated to be potentially at risk of
salinity, increasing to over 1.8 million ha by 2050. Perennial vegetation included both
remnant and plantation vegetation.
- An estimated 1500 plant species will be affected by salinity, with 450 possibly subject to
extinction.
- Salinity is likely to reduce fauna species by 30% in affected areas.
- Terrestrial animals will decline significantly (e.g. a 50% reduction in the number of water
birds using wheat belt wetlands is anticipated due to the salinity-induced death of shrubs
and trees).
- Species richness has already declined with the onset of salinity.
3
Land Monitor
The Land Monitor Project, as part of the WA Salinity Action Plan, mapped by another means
the current locations of salt-affected area and predictions of future salinity risk over the southwest agricultural zone (Caccetta et al. 2000). This process used land surface information and
satellite images (Landsat TM and digital elevation models (DEM’s)) to define areas of the
landscape that have a consistently low productivity that may be caused by salinity (Evans
2000, Dunne et al. 2001). On-ground truthing was then conducted and extrapolated to other
areas.
Advantages of the Land Monitor approach are that the process is 'electronic' and therefore able
to be updated and 'trained', and it reports its accuracy levels (George and Short 2006). The
biggest advantage of Land Monitor is that it reports at paddock and catchment scale, suitable
for use by land managers.
The Land Monitor Project also produced a DEM-derived product known as ‘height above flow
paths and areas at risk of high water table’, which is used as an indication of salinity hazard for
this project.
Rapid Catchment Appraisal
The Rapid Catchment Appraisal (RCA) project was initiated to support the state governments
State Salinity Strategy of 2000. The aim of RCA is to assess the condition of, and future risks
to, agricultural and natural resources within regional geographic catchments (Overheu 2003).
The process also attempts to identify the most suitable options to manage the risk. These
reports include assessments of the current and future risks of salinity at a catchment level.
RCA reports have been completed for several catchments within the South Coast NRM region,
which are available from the Department of Agriculture and Food Western Australia website
(www.agric.wa.gov.au).
Salinity Investment Framework
A Salinity Investment Framework (SIF) was developed as part of the WA Salinity Action Plan
and “is about setting priorities for salinity investment according to need, the level of threat to
our most important natural assets, saving our most important natural assets and getting value
for money”, (Sparks et. al 2006). The SIF focuses on the South West Agricultural Zone, which
included most but not all of the South Coast NRM Region.
As part of the SIF project, Natural Diversity Recovery Catchments were selected in order to
prioritise where public money would be invested to control salinity and maintain conservation
values (Walshe et. al 2004). These catchments were selected on the basis of their importance
for biodiversity and high level of threat from salinity (DEC 2003). To date six have been
established, with Walshe et al (2004) recommending further catchments to be included as
shown in Figure 1.
4
Figure 1: Current (hatched) and proposed Natural Diversity Recovery Catchments across the South
West Agricultural Zone (Walshe et al 2004)
Methods
Study Location
The South Coast NRM region includes approximately 9.7 million ha of the southern coastal
area of Western Australia, extending from Walpole in the west to Israelite Bay in the east and
inland to Ongerup and Salmon Gums. This area includes over 50 catchments (DoW 2007).
Data sets
Height Above Flow Path (HAFP) data is to be used to indicate areas that are at hazard from
salinity. This data was produced by the Land Monitor Project and was provided as a vector
dataset by Graeme Behn, Department of Environment and Conservation.
The HAFP of 0 to 0.5m was used to indicate the ‘low lying areas’, areas that have a salinity
hazard (John Simons, pers. comm. June 2008). These low lying areas are also at hazard from
other impacts of an altered hydrology such as higher runoff, higher recharge and water
accumulation and so are important to identify.
The locations of the priority biodiversity assets (the threatened flora, fauna and ecological
communities) were obtained from the Species and Communities Branch, Department of
Environment and Conservation. The threatened flora and fauna data was point data of all
recorded records of each threatened species, which the ecological communities data was
polygons of the locations of these communities.
5
The locations of the remnant vegetation in the region was determined using a polygon
shapefile of the remnant vegetation complied by the Department of Agriculture with assistance
from the Department of Environment and Conservation (DAWA/DEC 2006). To determine the
vegetation associations of this remnant vegetation, this shapefile was overlayed with a polygon
shapefile of Pre-European Vegetation (based on Beard’s vegetation associations mapping)
(DAWA/DEC 2007).
Data Analysis
Salinity Hazard was determined by intersecting the HAFP data with the locations of the priority
biodiversity assets and the remnant vegetation. For the threatened flora and fauna this
determined the percentage of records at hazard from salinity. For the threatened ecological
communities and the remnant vegetation, this determined the percentage of each vegetation
association at hazard from salinity.
This data analysis was conducted by Naeim Babaii, Geographic Information Services,
Department of Environment and Conservation using ArcMap 9.1.
Salinity Hazard Biodiversity Score
A salinity hazard biodiversity score was calculated for each of the catchments in the South
Coast NRM region by counting the number of biodiversity assets (threatened fauna, flora and
ecological communities) that were found to have a high salinity hazard that occurred in each of
the catchments. The assets were classified as having a high salinity hazard if:
- Fauna: 50% or more of the records of a species was located in the hazard area or is an
aquatic species or species which is reliant on water ecosystems.
- Flora: 50% or more of the records of a species was located in the hazard area
- Ecological communities: 50% or more of the records of a species was located in the
hazard area
This score was calculated to determine the catchments for which further salinity mapping
should be conducted.
Results and Discussion
Threatened Fauna
The South Coast NRM region has 57 listed terrestrial fauna species and 37 species classified
as priority. At least one location record of 30 of these threatened fauna species is located
within the salinity hazard area (Table 2). However, for 16 of these species less than 10% of
their records were located in this hazard area, and no more than 67% of records of a species
were located in this area.
Therefore salinity would probably not be a major threat for most threatened fauna species on
the South Coast. However, salinity would have the greatest potential to impact aquatic species
(e.g. Balston’s Pygmy Perch, Western Trout Minnow, Western Mud Minnow, Black-stripe
Minnow and the Sunset Frog) or species which rely on water ecosystems (e.g. Water-rat).
6
Table 2: The percentage of location records within the South Coast NRM region of threatened and
priority fauna which are within the salinity hazard area.
Rank
Percentage
of Records
at Hazard
CR
EN
EN
EN
EN
VU
VU
VU
VU
VU
VU
VU
VU
VU
VU
VU
EN
P3
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P5
P5
10.00
12.50
14.29
10.53
7.14
4.88
17.24
9.52
6.90
3.64
19.05
20.69
30.00
8.33
15.74
11.11
9.09
50.00
8.70
10.00
5.13
33.33
3.85
7.69
22.92
28.57
10.00
66.67
3.06
2.78
Threatened Fauna Species
Common Name
Scientific Name
Western Ground Parrot
Baudin's Black-Cockatoo
Carnaby's Black-Cockatoo
Western Trout Minnow
Dibbler
Australasian Bittern
Forest Red-tailed Black-Cockatoo
Recherche Cape Barren Goose
Chuditch
Western Mud Minnow
Numbat
Balston's Pygmy Perch
Brush-tailed Phascogale
Western Rosella (inland ssp)
Heath Mouse
Sunset Frog
Western Whipbird (w heath subsp)
Black-stripe Minnow
Australian Bustard
Hooded Plover
Crested Shrike-tit (sw ssp)
Water-rat
Western Brush Wallaby
Eastern Curlew
Crested Bellbird (southern)
White-browed Babbler (w wheatbelt)
Western Mouse
Western Whipbird (s WA subsp)
Quenda
Tammar Wallaby
Pezoporus wallicus flaviventrus
Calyptorhynchus baudinii
Calyptorhynchus latirostris
Galaxias truttaceus lesperius
Parantechinus apicalis
Botaurus poiciloptilus
Calyptorhynchus banksii naso
Cereopsis novaehollandiae grisea
Dasyurus geoffroii
Galaxiella munda
Myrmecobius fasciatus
Nannatherina balstoni
Phascogale tapoatafa ssp. (WAM M434)
Platycercus icterotis xanthogenys
Pseudomys shortridgei
Spicospina flammocaerulea
Psophodes nigrogularis nigrogularis
Galaxiella nigrostriata
Ardeotis australis
Charadrius rubricollis
Falcunculus frontatus leucogaster
Hydromys chrysogaster
Macropus irma
Numenius madagascariensis
Oreoica gutturalis gutturalis
Pomatostomus superciliosus ashbyi
Pseudomys occidentalis
Psophodes nigrogularis oberon
Isoodon obesulus fusciventer
Macropus eugenii derbianus
Total at Hazard = 30 species
Threatened Flora
The South Coast NRM region contains 127 declared rare flora (DRF) taxa and 779 taxa
classified as priority. At least one location record of 66 threatened flora species (7 DRF, 59
priority) is located in the salinity hazard area (Table 3). For 8 of these species, over 50% of
their records are at hazard. All the records of two species Apodasmia ceramophila and
Stachystemon vinosus are located in the salinity hazard area.
7
Table 3: The percentage of location records within the South Coast NRM region of threatened
and priority flora which are within the salinity hazard area.
Threatened Flora Species
Commersonia sp. Mt Groper (R. Cranfield & D.
Kabay 9157)
Microtis globula
Myoporum cordifolium
Orthrosanthus muelleri
Rhizanthella gardneri
Sphenotoma drummondii
Stachystemon vinosus
Astus duomilius
Atriplex muelleri
Coleanthera coelophylla
Conospermum coerulescens subsp. coerulescens
Cyathostemon sp. Dowak (J.M. Fox 86/271)
Dicrastylis archeri
Dillwynia acerosa
Acrotriche dura
Adenanthos cacomorphus
Angasomyrtus salina
Apodasmia ceramophila
Banksia aculeata
Bentleya diminuta
Caesia viscida
Daviesia campephylla
Frankenia brachyphylla
Haegiela tatei
Hybanthus volubilis
Hydatella australis
Isolepis australiensis
Keraudrenia adenogyna
Otion rigidum
Pimelea halophila
Wurmbea sp. Cranbrook (A.R. Annels 3819)
Allocasuarina hystricosa
Andersonia amabile
Astroloma microphyllum
Calytrix nematoclada
Chorizema carinatum
Conostephium marchantiorum
Cymbonotus preissianus
Desmocladus biformis
Goodenia filiformis
Hemigenia microphylla
Isopogon alcicornis
Lechenaultia acutiloba
Meziella trifida
Olax scalariformis
Parmeliopsis macrospora
Pityrodia chrysocalyx
Sarcocornia globosa
Rank
Percentage of
Records at
Hazard
R
2.78
R
R
R
R
R
R
P1
P1
P1
P1
P1
P1
P1
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P2
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
P3
9.47
4.55
12.50
16.67
17.65
100.00
4.71
20.00
8.96
11.11
1.64
15.00
66.67
2.22
4.88
20.00
100.00
6.74
37.50
11.43
50.00
25.00
7.41
7.23
14.29
25.00
2.78
17.07
11.11
27.27
50.00
6.67
28.57
7.14
17.39
16.81
66.67
5.88
4.42
14.29
9.52
50.00
33.33
33.33
6.06
4.48
25.00
8
Threatened Flora Species
Rank
Percentage of
Records at
Hazard
Stirlingia divaricatissima
Thelymitra jacksonii
Acacia aemula subsp. aemula
Asplenium aethiopicum
Billardiera drummondii
Centrolepis caespitosa
Corybas limpidus
Eremophila biserrata
Grevillea aneura
Jacksonia calycina
Lysinema lasianthum
Muiriantha hassellii
Pleurophascum occidentale
Pterostylis sp. Ongerup (K.R. Newbey 4874)
Regelia cymbifolia
Rumex drummondii
Siegfriedia darwinioides
Tyrbastes glaucescens
Total at Hazard = 66 species
P3
P3
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
P4
17.78
10.71
11.11
11.76
3.03
17.65
14.29
19.05
14.29
33.33
15.12
9.09
1.96
14.29
14.29
66.67
20.00
33.33
Threatened Ecological Communities
The South Coast NRM region including 6 threatened (TEC) and 20 priority (PEC) ecological
communities. At least part of two TEC and seven PEC’s occur in the salinity hazard area
(Table 4). For most of these communities only a small percentage are at hazard of salinity, but
nearly all of the Herblands and Bunch Grasslands TEC, while over 60% of the Ironstone heath
and nearly 50% of Banksia Coccinea thicket PEC are within the hazard area.
Therefore, salinity has the potential to be a major threatening process for the Herblands and
Buch Grasslands TEC. Further research should also be conducted to determine the level of
potential threat for the Ironstone heath and Banksia Coccinea thicket.
Table 4: The threatened and priority ecological communities that at least part of occur within the
salinity hazard area and the percentage of the area of each within this hazard area.
Threatened Ecological
Communities
Montane
Herblands and Bunch Grasslands
Cheynes2 Open Tree Mallee
Montane Mallee
Banksia coccinea thicket
Reedia swamps - Warren region
Esperance
Esperance Sandplain
Ironstone heath (wet)
Rank
Percentage
of Total Area
at Hazard
Critically Endangered
Vulnerable
Priority
Priority
Priority
Priority
Priority
Priority
Priority
0.12
99.99
0.89
0.17
46.17
9.41
0.06
36.44
60.53
9
Remnant Vegetation
The South Coast NRM region contains approximately 120 Beard vegetation associations. At
least part of 100 of the remnant vegetation of these associations occur in the salinity hazard
area (Table 5). For the majority of these, only a small percentage of the vegetation association
occurs in the salinity hazard area. However, for five of these associations over 50% of their
current occurrence occurs in the salinity hazard area. These would be the vegetation
associations for which further research should be conducted to determine the risk of this
hazard.
Table 5: The vegetation associations of the remnant vegetation of the South Coast region that at least
part of which occur within the salinity hazard area and the percentage of each association within this
hazard area. % of original and current occurrence of veg assoc gives the (a) percentage of the original
association occurrence that remains in the region; (b) the percentage of the original association
occurrence that remains in Western Australia; (c) the percentage of the current occurrence of the
association occurring in the region; and (d) the percentage of the original occurrence that occurred in
the region.
Veg
Assoc
Code
No
1
Beard
Code
4
e1Tc
e2,3M
c
e3,5Mi
7
e5,6Mi
8
e8,34
Mi
9
e12,13
Mi
10
14
23
e22Mi
e2Lc
e2bLi
27
mLi
3
38
41
e6Mr
m5Sc
xSc
mSi
42
eaSi
31
48
e26SZ
c
xSZc
50
xZi
51
xGc
125
126
128
129
sl
fl
r
ds
142
e6,8Mi
352
e6Mi
47
Vegetation Association Description
Tall forest; karri (Eucalyptus diverscolor)
Medium forest; jarrah-marri
Medium woodland; marri & wandoo
Medium woodland; York gum (E.
loxophleba) & wandoo
Medium woodland; salmon gum & gimlet
Medium woodland; coral gum (E.
torquata) & goldfields blackbutt (E. le
soufii) (also some e10,11)
Medium woodland; red mallee group
Low forest; jarrah
Low woodland; jarrah-banksia
Low woodland; paperbark (Melaleuca
sp.)
Shrublands; Melaleuca thyoides thicket
with scattered York gum
Shrublands; thicket, mixed
Shrublands; teatree scrub
Shrublands; mallee & acacia scrub on
south coastal dunes
Shrublands; tallerack mallee-heath
Shrublands; scrub-heath
Shrublands; dwarf scrub on granite
(South coast)
Sedgeland; reed swamps, occasionally
with heath
Bare areas; salt lakes
Bare areas; freshwater lakes
Bare areas; rock outcrops
Bare areas; drift sand
Medium woodland; York gum & salmon
gum
Medium woodland; York gum
% of original and current
occurrence of Veg Assoc
a
b
c
d
% at
Salinity
Hazard
16,154
58
78
17
24
3.8
284,049
46
71
12
19
7.2
17,340
16
23
6
9
23.8
136
37
13
1
0
45.9
5208
4
47
0
0
0.3
6925
75
100
0
1
0.0
44,841
72,650
5322
31
75
89
98
75
76
0
99
11
1
99
9
1.3
7.7
0.6
50,202
80
73
38
34
10.7
209
95
26
27
8
0.1
2444
5255
100
45
100
92
99
3
99
6
1.6
28.6
124,235
88
96
25
27
2.6
364,471
35
36
96
97
9.6
3768
17
29
19
30
19.1
4523
71
71
100
100
0.7
11,926
40
59
27
39
9.0
129,227
3760
30,251
16,154
22
39
69
42
92
94
85
58
0
2
5
14
1
4
6
20
9.1
43.1
1.2
1.6
334
12
26
0
0
15.7
7197
28
16
6
3
11.1
Total Ha
in
Region
10
Veg
Assoc
Code
No
380
x3SZc
413
a33Sc
423
aSZc
482
486
511
Beard
Code
e11,22
Mi
e8,22
Mi/e15
Si
e8,9Mi
512
e15,32
Si
515
e30Si
516
e27Si
519
e15Si
676
e8,22
Mi
k3Ci
691
edSc
697
x7SZc
521
925
929
931
e15,22
Si
e22Si
e33Lc
e7Mi
934
e28Si
936
938
e8Mi
e6,7Mi
e6Mi
mSp
k3Ci
e27Si/
e26SZ
c
e7Mi/e
27Si
924
939
940
942
963
964
965
967
968
969
e7mMi
e27,67
Si
e2,3Mi
e5,7Mi
e2,3,5
Mi
e2,3M
c/e2Lc
Vegetation Association Description
Shrublands; scrub-heath on sandplain
Shrublands; Acacia neurophylla & A.
species thicket
Shrublands; Acacia scrub-heath
unknown spp
Medium woodland; merrit & red mallee
Mosaic: Medium woodland; salmon gum
& red mallee / Shrublands; mallee scrub
Eucalyptus eremophila
Medium woodland; salmon gum & morrel
Shrublands; mallee scrub, Eucalyptus
eremophila & Forrest's marlock (E.
forrestianna)
Shrublands; mallee scrub, blue mallee
(Eucalyptus socialis)
Shrublands; mallee scrub, black marlock
Shrublands; mallee scrub, Eucalyptus
eremophila
Medium woodland; salmon gum & red
mallee
Succulent steppe; samphire
Shrublands; Dryandra quercifolia &
Eucalytpus spp. thicket
Shrublands; scrub-heath on lateritic
sandplain in the southern Geraldton
Sandplain Region
Shrublands; mallee scrub, Eucalyptus
eremophila & red mallee
Shrublands; mallee scrub, red mallee
Low forest; moort (E. platypus)
Medium woodland; yate
Shrublands; mallee scrub Eucalyptus
nutans
Medium woodland; salmon gum
Medium woodland; York gum & yate
Succulent steppe with woodland;
yorkgum, sparse teatree scrub &
samphire
Mosaic: Shrublands; mallee scrub, black
marlock / Shrublands; tallerack malleeheath
Mosaic: Medium woodland; yate /
Shrublands; mallee scrub, black marlock
Medium woodland; yate & paperbark
(Melaleuca spp)
Shrublands; mallee scrub, black marlock
& Eucalyptus decipiens
Medium woodland; jarrah & marri
Medium woodland; wandoo & yate
Medium woodland; jarrah, marri &
wandoo
Mosaic: Medium forest; jarrah-marri /
Low forest; jarrah
Total Ha
in
Region
% of original and current
occurrence of Veg Assoc
a
b
c
d
% at
Salinity
Hazard
480
24
53
0
0
14.6
1351
100
47
37
17
0.1
18,397
79
82
83
86
0.5
638,530
62
99
2
3
1.2
154,427
24
62
18
47
8.8
3618
24
65
0
0
6.8
61,143
25
25
98
99
18.0
60,361
5
100
0
0
0.0
339,947
44
53
71
84
6.8
789,878
53
60
15
17
2.8
20,327
80
100
2
2
1.0
75
9
95
0
0
5.7
34,967
98
78
98
78
2.9
23,609
16
29
35
61
28.9
61,629
22
55
23
56
5.0
3759
7623
13,476
71
76
43
73
75
43
90
95
94
93
93
94
1.1
4.6
23.4
4285
85
85
100
99
4.6
38,479
18,212
36
20
97
20
0
98
0
98
2.1
21.3
6
6
6
100
100
59.2
111,269
41
41
100
100
6.2
10,403
25
25
100
100
19.3
575
21
38
14
25
55.4
1545
41
41
100
100
12.7
3214
11,843
44
12
55
12
59
79
72
79
11.3
30.6
33,580
39
33
33
28
7.9
10,692
35
35
100
100
8.0
11
Veg
Assoc
Code
No
Beard
Code
971
e67Si
972
e2,3,5,
7Mi
973
mLc
974
975
976
977
978
979
980
e6,8,9
Mi
e2Li
mLi
k3Ci
mcLc
e2,65,
c7Lc
e2,3M
c/ecLc
982
986
987
e2SZc
e5,6,7
Mi
e67Li
enSZc
e2,5Mi
991
e5Mi
993
c5e6M
i
994
e2cLc
981
1003
1004
1023
1047
1073
1075
1077
1085
1088
1095
1130
1134
1139
e2,3,5
Mc
e5Mr/x
Zc
e5,6,8
Mi
e29SZ
c
e5,64
Mi
e15,27
Si
e2,18
Mi
e5,69
Mi
e64,69
Mi
e6,7,8
Mi
e1,68
Tc
e2Mi
e1,74
Tc
Vegetation Association Description
Shrublands; mallee scrub, Eucalyptus
decipiens
Medium woodland; jarrah, marri, wandoo
& yate
Low forest; paperbark (Melaleuca
rhaphiophylla)
Medium woodland; York gum, salmon
gum & morrel
Low woodland; jarrah
Succulent steppe with low woodland;
myoporum over samphire
Low forest; teatree & casuarina
Low forest; jarrah, Eucalyptus staeri &
Allocasuarina fraseriana
Mosaic: Medium forest; jarrah-marri /
Low forest; jarrah & casuarina (probably
Allocasuarina fraseriana)
Shrublands; jarrah mallee-heath
Medium woodland; wandoo,York gum &
yate
Low woodland; Eucalyptus decipiens
Shrublands; mallee-heath (Stirling Ra.)
Medium woodland; jarrah & wandoo
Medium woodland; small wandoo
patches surrounded by e2, 5Mi; e5, 7Mi
Medium woodland; York gum &
Allocasuarina huegeliana
Low forest; jarrah & casuarina (probably
Allocasuarina fraseriana)
Medium forest; jarrah, marri & wandoo
Mosaic: Medium open woodland; wandoo
/ Shrublands; mixed heath
Medium woodland; York gum, wandoo &
salmon gum (E. salmonophloia)
Shrublands; Eucalyptus incrassata
mallee-heath
Medium woodland; wandoo & mallet
Shrublands; mallee scrub, Eucalyptus
eremophila & black marlock (E.redunca)
Medium woodland; jarrah & river gum
Medium woodland; wandoo & blue mallet
(E. gardneri)
Medium woodland; mallet & blue mallet
Medium woodland; York gum, yate &
salmon gum
Tall forest; karri & red tingle (E. jacksonii)
Medium woodland; jarrah (south coast)
Tall forest; karri & yellow tingle (E.
guilfoyleii)
Total Ha
in
Region
% of original and current
occurrence of Veg Assoc
a
b
c
d
% at
Salinity
Hazard
206
61
61
100
100
88.8
9176
37
37
100
100
37.5
1662
60
33
81
44
54.3
866
8
8
100
100
32.4
11,843
92
91
76
75
0.3
1173
30
30
100
100
69.1
141
47
47
100
100
15.5
20,784
37
37
100
100
2.6
1431
15
15
100
100
8.2
69,560
42
42
100
100
6.1
1321
9
9
100
100
28.4
813
15,930
802
47
51
88
47
51
36
100
100
61
100
100
25
13.1
6.9
2.5
271
86
86
100
100
10.2
792
29
29
100
100
37.3
5201
29
29
100
100
6.9
672
77
42
11
6
0.1
2556
24
37
56
83
48.2
639
7
7
0
0
38.9
188,021
9
85
2
16
1.3
146
17
33
2
5
6.2
23,447
10
12
29
36
22.2
1547
48
48
100
100
47.6
742
7
9
16
20
22.1
22
11
35
16
49
2.6
527
19
19
100
100
48.9
992
70
90
4
5
0.0
4326
62
83
5
7
2.7
14,909
84
93
29
32
3.4
12
Veg
Assoc
Code
No
Beard
Code
1144
e1,3Tc
1150
1151
1152
1153
e1,68,
74Tc
e2,68
Mc
e2,74
Mc
e2,75
Mc
1200
e8,9Mi
/e15,2
7Si
1413
acmSc
1516
1967
2048
e27,32
Si
e5,7,1
8Mi
x13SZ
c
2051
mLc
xGc
3106
e8,14
Mi
4048
x15SZ
c
4801
nLr
xZc
6048
bSZc
7048
bSZc
Vegetation Association Description
Tall forest; karri & marri (Corymbus
calophylla)
Tall forest; karri, red tingle & yellow tingle
Total Ha
in
Region
a
b
c
d
% at
Salinity
Hazard
17,530
100
79
0
0
5.3
5158
95
96
90
90
0.5
2016
96
93
91
87
4.8
7323
98
99
51
51
2.4
1039
87
87
100
100
0.3
3355
6
8
20
28
28.4
42,305
85
74
0
0
0.2
59,757
24
44
38
70
11.7
7704
22
22
100
100
39.7
14,949
76
48
3
2
0.7
7780
71
71
100
100
10.4
20,374
24
98
0
2
1.8
30,472
55
65
66
78
2.4
8475
12
15
75
96
11.9
17,624
15
15
100
100
20.0
110,516
63
82
38
49
0.9
Medium forest; jarrah & red tingle
Medium forest; jarrah & yellow tingle
Medium forest; jarrah & Rates tingle
Mosaic: Medium woodland; salmon gum
& morrel / Shrublands; mallee scrub
Eucalyptus eremophila & black marlock
(E. redunca)
Shrublands; acacia, casuarina &
melaleuca thicket
Shrublands; mallee scrub, black marlock
& Forrest's marlock
Medium woodland; wandoo, yate & river
gum
Shrublands; scrub-heath in the Mallee
Region
Sedgeland; sedges with low tree
savanna woodland; paperbarks over &
various sedges
Medium woodland; salmon gum &
Dundas blackbutt
Shrublands; scrub-heath in the
Esperence Plains incl. Mt Ragged scrubheath
Shrublands; heath with scattered Nuytsia
floribunda on sandplain
Shrublands; banksia scrub-heath on
sandplain in the Esperence Plains
Region
Shrublands; banksia scrub-heath on
coastal plain in the Esperence Plains
Region
% of original and current
occurrence of Veg Assoc
Total number of vegetation Associations = 100
Salinity Hazard Biodiversity Score
The South Coast NRM region includes 58 catchments. The Salinity Hazard Biodiversity Score
developed to indicate the catchments that contain the most biodiversity assets that have a high
salinity hazard is shown in Appendix 1. Twenty-six of these catchments contain at least one
biodiversity asset that had a high salinity hazard. The Irwin Inlet_Kent_Bow catchment had the
greatest score, followed by Moates_Goodga_Angove, Nornalup Inlet_Frankland River, Oyster
Harbour_Kalgan King and Torbay Inlet catchments.
13
Salinity Hazard Biodiversity Scores were also calculated for threatened fauna, flora and
ecological communities separately, as are shown in Appendix 1. The catchments with the
highest scores for each of these groups were:
- Threatened Fauna: the western catchments of the region, in particular the Irwin
Inlet_Kent_Bow catchment.
- Threatened Flora: the central catchments, in particular, the Stokes Inlet_Lort_Young,
Jerdacuttup River, and Culham Inlet_Phillips_West_Steere catchments.
- Threatened Ecological Communities: Oyster Harbour_Kalgan_King, Moates_Goodga_
Angove and Magenta Internal catchments. Of most concern is the Magenta Internal
catchment which contains the most at hazard community, the Herblands and Bunch
Grasslands.
Constraints and issues
The methodology that was used for this salinity hazard assessment was used in order to give
regional overview of the potential salinity hazard to the regions biodiversity. However, due to
the broadness of the project and the availability of data there are some constraints which affect
the accuracy of the hazard assessment. These include:
- The Height Above Flow Path (HAFP) of 0 to 0.5m indicates the ‘low lying areas’ of a
catchment, but this does not necessarily mean hazard of salinity for some catchments, as
many other factors in a catchment, such as general topography, water table levels, etc,
affect the HAFP of which is hazard of salinity for that catchment. However, John Simons,
an experienced hydrologist in the Department of Agriculture in Esperance, has found that 0
to 0.5m is a good general indicator of hazard of salinity.
- The HAFP data is derived from Landmonitor satellite imagery. However, this imagery
misses some of the coastal areas of the South Coast NRM region, so there are some gaps
in the data. HAFP has also not been determined for some of the Esperance sand plain
region in the northwest of the South Coast region.
14
Recommendations
The results of this project are intended as only a guide to identifying priority biodiversity assets
and catchments in the South Coast NRM region for which further research into the risk and
impacts of salinity should be conducted. These results do not identify the degree to which the
assets would be affected by salinity.
This salinity hazard mapping project has identified the priority biodiversity assets (threatened
fauna, flora and ecological communities) that are at most hazard from salinity for the South
Coast NRM region. Research into the susceptibility of the identified biodiversity assets to
salinity and the potential impacts of salinity to habitat should be made a priority.
The salinity hazard biodiversity scores identified the catchments at which the greatest numbers
of priority biodiversity assets were at hazard from salinity. Priority should be given to these
catchments for salinity risk mapping to identify the risk of salinity on these biodiversity assets.
It is recognized that more detailed mapping of some of these identified catchments has already
been conducted through programs such as the RCA’s (www.agric.wa.gov.au), however further
research including the susceptibility of the biodiversity assets in these catchments would still be
a priority. Spies and Woodgate (2005) outline a methodology for salinity mapping in the
Australian context which should be considered as a method to use for salinity risk mapping in
the South Coast region.
The Natural Diversity Recovery Catchments identified in the Salinity Investment Framework
(SIF) are different from the priority catchments identified using the salinity hazard biodiversity
scores in this report. As well as threatened species, the Natural Diversity Recovery
Catchments take into account the representative of areas of high biodiversity value (DEC
2003).
15
16
References
Caccetta, P., Allen, A. & Watson, I. (2000) The Land Monitor Project, www.cmis.csiro.au/
RSM/research/pdf/CaccettaP_Impaper2000.pdf, accessed: 20 June 2008.
Cramer, V. A. & Hobbs, R. J. (2002) ‘Ecological consequences of altered hydrological regimes
in fragmented ecosystems in southern Australia: impacts and possible management
responses’, Austral Ecology, 27, p. 546-564.
Danks, A. (2004) South Coast Biodiversity: an Overview of Biodiversity Values, Threats and
Conservation in the South Coast Region, Department of Conservation and Land Management,
Albany.
DAWA/DEC (Department of Agriculture/Department of Environment and Conservation) (2006)
Remnant Vegetation, accessed June 2008, Department of Environment and Conservation.
DAWA/DEC (Department of Agriculture/Department of Environment and Conservation) (2007)
Pre-European Vegetation, accessed June 2008, Department of Environment and Conservation.
DEC (Department of Environment and Conservation) (2003), Salinity Investment Framework
Interim Report – Phase 1, Department of Environment and Conservation, Salinity and Land
Use Impacts Series No. SLUI 32.
DoW (Department of Water) (2007) Hydrographic Catchments, digital data (ArcMap shapefile),
accessed: March 2008, Department of Environment and Conservation.
Dunne, R., Caccetta, P. & Beetson, B. (2001) Predictions of Areas at Risk of Salinity: The
Agricultural area of Western Australia, Report number CMIS 01/183,
www.rss.dola.wa.gov.au/landmon/reports/, accessed 20 June 2008, Land Monitor Project.
Environmental Protection Authority (2007) State of the Environment Report: Western Australia
2007, www.soe.wa.gov.au, accessed: 20 June 2008, Department of Environment and
Conservation, Perth, Western Australia.
Evans, F. H. (2000) Land Monitor Salinity Risk Prediction Dumbleyung and Mt Barker
Regions, CSIRO CMIS Task Report No. 2000/45.
George, R. & Short, R. (2006) Estimating the extent of salinity, http://www.agric.wa.gov.au/
content/ LWE/SALIN/SMEAS/salinity_extent.htm, accessed 24 June 2008, Department of
Agriculture and Food Western Australia.
Short, R. & McConnell, C. (2000) Extent and Impact of Dryland Salinity in Western Australia,
Agriculture Western Australia
Sparks, T., George, R., Wallace, K., Pannell, D., Burnside, D. & Stelfox, L. (2006), Salinity
Investment Framework Phase II, Western Australian Department of Water, Salinity and Land
Use Impacts Series, Report No. SLUI 34, 86p.
17
Spies, B. & Woodgate, P. (2005) Salinity Mapping Methods in the Australian Context: Users
Guide, Commonwealth of Australia: Department of the Environment and Heritage; and
Agriculture, Fisheries and Forestry, Canberra.
Overheu, T. (2003) Albany Eastern Hinterland Catchment Appraisal 2002, Resource
management technical report 242, www.agric.wa.gov.au, accessed 26 May 2008, Department
of Agriculture.
Walshe, T. V., Halse, S. A., McKenzie, N. L. & Gibson, N. (2004), Towards identification of an
efficient set of natural diversity recovery catchments in the Western Australian Wheatbelt,
Records of the Western Australia Museum Supplement No. 67, pp. 365-384.
18
Appendix 1
The salinity hazard biodiversity scores for the catchments of the South Coast NRM region. The scores
represent the numbers of biodiversity assets that were identified through the salinity hazard assessment
as been at most hazard from salinity.
19
20
Figure 1.1: The salinity hazard biodiversity scores for the catchments of the South Coast NRM region. The scores represent the number of biodiversity assets that were identified through the salinity hazard assessment as been at most hazard from salinity.
21
Figure 1.2: The threatened fauna salinity hazard biodiversity scores for the catchments of the South Coast NRM region. The scores represent the number of biodiversity assets that were identified through the salinity hazard assessment as been at most hazard from salinity.
23
Figure 1.3: The threatened flora salinity hazard biodiversity scores for the catchments of the South Coast NRM region. The scores represent the number of biodiversity assets that were identified through the salinity hazard assessment as been at most hazard from salinity.
25
Figure 1.4: The threatened ecological communities salinity hazard biodiversity scores for the catchments of the South Coast NRM region. The scores represent the number of biodiversity assets that were identified through the salinity hazard assessment as been at most
hazard from salinity.
27