Post on 03-Jan-2022
transcript
AN ASSESSMENT OF SECONDARY DRYLAND SALINITY IN VICTORIA
February 1994
CENTRE FOR LAND PROTECTION RESEARCH
Technical Report No. 14
Land Protection Branch
(•) Department of Conservation
AN ASSESSMENT OF SECONDARY DRYLAND SALINITY IN VICTORIA
February 1994
CENTRE FOR LAND PROTECTION RESEARCH
Technical Report No. 14
Margaret Allan
ISBN No. 0 7306 4046 9
ISSN No. 1038-216X
Land Protection Branch
Department of Conservation & Natural Resources
Allan, M.J.
631.41 6
An assessment of secondary dry land salinity in Victoria
Bibliography. ISBN 0 7306 4046 9
1. Salinity - Victoria. I. Centre for Land Protection Research. II. Victoria. Dept. of Conservation and Natural Resources. III. Title. (Series: Technical Report (Centre for Land Protection Research (Vic.)); no. 14).
2 Department of Conservation & Natural Resources
CONTENTS
ABSTRACT ... .............. ........ ................ ............ ........... ...... .... ....... .. ...... ........................ .......... .... .... ... ........ .. .. ...... ... ..... 5
INTRODUCTION .............................................. ......... ... ....... ............ .... ... ..... ............ .... .. .... .. .. ... ... ... ..... .... ......... ..... .. .. 5
Statewide Estimates of Dry land Salinity ..................... .. .............. .. ....................... ............. ... ... ..... ... ....... .......... ..... 5
Early Regional Mapping ............................. ............. ...... .............. ....................... ... ... ... ... ....... ....... ... .......... ...... ... .. 6
The Statewide Dryland Salinity Assessment Project .......... .. ........ .. ................................ ............ .... .... .. .. .... ........ .. . 6
Primary Salinity ......................... .......... ... ......... ... ....................... .. ... ..... ..... ... .. ...... .. .... .... .. ... ........... .... .... ....... ...... .. 6
METHOD ... ....... .. .. .... ............... .... ........ .... ... .... ......... ........... ...... .......... ......... .. ................ ..... ........ ..... ......... .... .... .. ...... .. ?
Field Procedure ..... ............... ...... .. ....... ................... ..... ...... ........ ... ........... ........ .. ... .... ...... ..... .... .. .... .... .. ..... .... ..... .. .. 7
Recognizing and Assessing Salinity .... .... ... ......... ....... ...... ... .. ............................. .... ............... ......... .. ..... ... .... ...... ... 7
The Mapping Procedure ............................... ....... .... ....... ... ......... .......... ... .... ..... ........ ... ..... ... .. .......... ... .. ........... .... .. 8
Determining the Origin of Salinity ................ .. .. ..... ...... ....... ............ ........ .... ............ ........ .... ........................ .. .. ... ... 8
RESULTS ... .... ........ ...... ......... ... ............... ..... .... ........... ................ ... ..... .. ........ .. .. ....... .... ...... .. .. .... ...... ... .. .. ....... .. .. ...... .. 8
Dryland Salinity in Victoria ..... ...... .. ..... ... ... .... ... ...... ........... ..... ....... .. .. ..... .... ....... ........ ...... ......... ...... .. .. ... .. ...... ...... 8
The Victorian Dry land Salinity Database ....... : .... ......................... ...... ........... ..... ............. .. ... .. .. .. .......... .............. .. . 9
Rate of Spread of Dry land Salinity .......... .. ........ .. ....... .. ..... .............................. ... .. ......... ................. .. ..... .... .. ........ 13
Salinity Classes ..................................................... .......... ...... ... .... .. .. ..... ....... ................. ...... ...... .. ... ..... ..... ... .... .... 13
An Overview ofDryland Salinity Discharge by Salinity Region .......................... .............. .................. ........ .. .... 13
CONCLUSIONS ... ......... ... .... ........ .......... ... .... ......... ........... .. .... ............ ....... ............. ... ......... ... ... .... ...... ... .... .... ...... .... 15
RECOMMENDATIONS .......... .. ... ... .. ....... .... .... ............ ..... ..... ...... .... ....... ..... ............ ........ ... ... .. ... .. ...... .... ...... ... .... .... 15
ACKNOWLEDGEMENTS ........ ............. ...... ...... ..... ............ ........ ....... .......... ....... .... ........................ ........ .... ..... ... ..... 16
REFERENCES ....... .......... ........... .... ....... .. .... .. ....... ......... .. .... ...... ..... ......... ........... ..... ...... ... .. ............ ... ........ .. .... .... ... .. 16
APPENDICES
Appendix 1. Recognising and Confirming Salinity .............. .. .. ...... ....... .... ..... .... .................... .......... .... ............... .. ... 18
Appendix 2. Salt Tolerant Plants .............................. ........... ...... .. ........ ... ......... ..... ............... ........ .. ... .... ..... ... .. .. .. ..... . 21
Appendix 3. Some Known Salt Sensitive Plants ............................ .. ........ .... .... ...... ........ ...................... ........ .. .. .. .. .... .24
Department of Conservation & Natural Resources 3
List of Maps
Map 1. Dry land Salinity Planning Regions. .............. ..... ...................... ...... ...... .............. ............ ............ .... ...... ...... .. 11
Map 2. CNR Regional Boundaries. .......................................................................................................................... 12
Map 3. Distribution ofDryland Salinity in Victoria (inside back cover)
List of Tables
Table 1. Natural Salinity in Victoria .......................... ...... .... .... .. ... .......... .. .......... .. ................. ........ .. ............. .... .......... ?
Table 2. Secondary Dryland Salinity by Salinity Planning Region ....................... ................................ ..... ................ 9
Table 3. Secondary Dryland Salinity in Victoria by CNR Region .... .. ........................ .............. .. ............ .. .... ........... 10
Table 4. Size Analysis on Discharge Sites in the Victorian Dryland Salinity Database by Salinity Plan Region .... 10
Table 5. Size Distribution of Discharge Sites in the Database ............ .... ............ .......................... ........ ......... ........... 13
4 Department of Conservation & Natural Resources
AN ASSESSMENT OF SECONDARY DRYLAND SALINITY IN VICTORIA
February 1994
M.J.ALLAN
Centre for Land Protection Research, Department of Conservation and Natural Resources, 22 Osborne Street, Bendigo, Victoria, 3550
ABSTRACT
The amount of land affected by secondary dry land salinity in Victoria has been calculated to total 120 000 hectares.
The majority of the discharge sites have been assessed, recorded onto 1:25 000 scale maps, and are contained on the
Victorian Dryland Salinity Database. ·
Dryland salinity occurs in most regions of the State, except the forested Eastern Highlands. The more intensely
affected areas include the Mallee, the Wimmera, the Hamilton area, central Victoria, Colac region, Phillip Island and
Lake Wellington hinterland. A portion of the affected areas were salty before European settlement, however a number
of these sites have expanded or increased in severity due to land-use change since settlement.
INTRODUCTION
t Pry land salinity is a term used to describe salt that has
J )milt up in soil and water syste~s as a consequence of
f~.~native v~getatio~ clearing and its replacement w~t~ Io~ . i'water-usmg agncultural systems. Secondary salm1ty IS
\
used specifically to describe dryland salinity that has
occurred since European settlement, and to distinguish it
from primary (natural) salinity which existed long before
settlement.
Irrigation salinity is not addressed in this report, as the
causes of and solutions to the problem vary to those of
dryland salinity.
The Statewide Dryland Salinity Assessment (SDSA)
Project commenced in 1989, with the aim of collating
existing data on secondary discharge1 sites, and to
coordinate the collection of further data by CNR
regional staff, in order to derive accurate figures on the
extent of the problem. Previously, there had been a
variety of methods used to assess and classify salinity
sites so that direct comparisons between regions were
not possible. Also, not all parts of the State had been
surveyed and consequently estimates of the total area
affected by salinity in Victoria varied widely (see
1 Discharge refers to the dissipation of groundwater which is the driving·force behind dryland salinity.
following).
Statewide Estimates of Dry land Salinity
In the 1950s, Cope (1958) conducted the first appraisal
of dryland salinity in the State and estimated there to be
over 5000 ha affected.
After a series of wet years in the early seventies led to a
rapid expansion in area of discharge, interest in the
phenomenon of dryland salinity increased and further
surveys were carried out. By 1978 a figure of 85 000 ha
was used by the Soil Conservation Authority (1978) for
total dryland salinity in the state. In 1983 it was
estimated that 90 000 ha of 'seeps' (dryland discharge
sites) and 60 000 ha of scalds (where erosion of topsoil
leaves salty subsoil exposed) existed when ACIL (1983)
completed a study on dryland salinity for the
Government of Victoria. However when the major
policy document "Salt Action:Joint Action"
(Government of Victoria 1988) was released, a
conservative estimate of 55 000 ha of dryland salinity
was employed, which represented only the area of
salinity which was confidently known to exist.
Department of Conservation & Natural Resources 5
Early Regional Mapping
Prior to the establishment of th is project, a small number
of regions had been mapped for dryland salinity, and a
total of 18 000 ha were recorded.
A study of salinity in north-west Victoria (west of a line
from Swan Hill to Wycheproof) in the late-1960s
calculated that there were 5000 ha of salinity due to both
local and regional groundwater systems (Rowan 1971 ).
The amount of salinity was determined by Rowan to
The survey method of salt-affected land was based on
earlier work conducted under the federally funded
National Soil Conservation Program (NSCP) project
ISCON - the Inventory of Soil Conservation Needs
(Salinity Component). Extensive field work was
conducted under ISCON to develop a methodology for
recognising, assessing and recording dryland salinity
sites in Victoria (Matters 1987a; Matters 1987b ). The
basic tenet underlying the identification of discharge
sites was the use of plants as indicators of salinity.
have been underestimated as sites were mapped from Primary Salinity aerial photographs with limited ground-truthing.
It has been estimated that around 250 000 ha of natural
From 1976 to 1980 a fiel d survey of dryland salinity was (also known as primary) salting exists in Victoria (see
conducted in the Soil Conservation Authority region of Table 1). There are a number of types of natural salting
Otway (Duff 1983), and 7500 ha were identified. Three as described below.
categories of severity were used, however the categories
were not applicable across the state.
A comprehensive salinity survey was detailed in a report
prepared by the Ballarat Region (DCFL 2 1988). The
report incorporated previous fieldwork conducted over
sub-sections of the Region (Sturmfels 1982; Duff 1983;
Moore 1984) and in total 5500 ha of saline discharge
was recorded. A rating for severity of salinity was
allotted to some of the sites.
These surveys demonstrate the variation in approach to
salinity mapping which had been adopted, and
highlighted the need for a standardized methodology to
be used in all regions so that comparisons and priorities
for Statewide action could be made.
Salt marshes
This term is used to describe coastal plant communities
growing within the tidal influence of the sea (the source
of salts in these cases). A variety of native plants are
found in Victorian salt marshes (refer Bridgewater et al.
1981 ). An estimated 70 000 ha of salt marsh exists in
Victoria (Table 1), the main locations being Discovery
Bay (western Victoria), Westernport Bay, Andersons
Inlet, north of Wilsons Promontory, and along the
Gippsland Lakes.
The degree of influence. of the sea on the watertable
along the Victorian coast varies with geological
conditions. The coincidence of salt marsh and adjacent
dryland (groundwater driven) salting has been recorded
The Statewide Dryland Salinity Assessment in Yarram Region. A bore at one such site is artesian,
Project and the influence of seawater cannot be completely
discounted in this case.
A coordinated effort across the State was made to map
all known but previously unrecorded dryland salinity Salt pans
sites, and as far as possible, locate and record newly
emergent and previously unknown sites. In addition These are areas where the watertable is intermittently at
information was collated on expansion rates. the surface, and soil salinity levels are too high to allow
2 Department of Conservation, Forests and Lands (DCFL) is now called Department of Conservation and Natural Resources. DCFL Regions, of which Ballarat
was one, have been superseded by catchment based
management.
6 Department of Conservation & Natural Resources
plant growth. Such sites have also been known as 'salt
lakes' . Salt pans are predominantly found in · north
western Victoria, though this category also includes the
Lake Corangamite lacustrine complex (Working Party
on Dryland Salting 1982), and lakes around Willaura in
western Victoria.
Salt flats A total of I 00 000 ha of salt pans and salt flats is
Land with watertable close to, but not at the surface, estimated to exist in Victoria (SCA I983).
supporting salt-tolerant plants. Distributed throughout
the Mallee and Wimmera.
Table 1: Natural Salinity In Victoria (areas in hectares)
0
*
+
Note:
Wetlands0
Semi-permanent saline (includes coastal and inland) 66 IOO
Permanent saline - Intertidal flats (exclusively coastal) 69 IOO
- Shallow (predominantly inland) 3I 300
- Deep (predominantly inland) 40 700
Subtract: Freshwater wetlands that have become saline * 4 900
Man-made saline wetlands (mainly evaporation basins) 1 500
Saline areas increased in size 60
Total natural saline wetlands in Victoria 199 740
Dry lands
Estimated natural saline drylands (salt flats) in Victoria+ 50 000
Total natural salinity in Victoria 249 740
Wetlands data from Andrew Corrick, Wetland Survey Group, Flora and Fauna Branch, CNR.
Conservative estimate of total amount salinized, as it is impossible to determine the original condition of all wetlands, and hard to quantify land-use effects since European settlement (Corrick pers. comm.) .
S.C.A. estimate (Speedie and Gibbons, 1984) oftotal natural inland dryland and wetland salinity is 100 000 hectares. No separate calculation was made for amount of salt flats in Victoria, so it was assumed to be half (50 000 ha). Salt pans are quantified in Corrick's survey as they are permanent, saline wetlands (shallow and deep); salt flats (where the watertable is below the surface) are not.
Definitions for both salt pans and salt flats vary slightly between the Wetland Survey Group where pans and flats are coastal or inland, and Dryland Salinity Research (see S.C.A. 1983) where the terms are used exclusively for inland natural discharge sites.
METHOD
Field Procedure
remaining sites were located by systematic surveys m
each of the study areas.
At each of the discharge sites an examination and record
Field work was conducted by assessors who were was made of evidence for dryland salinity . Once salinity
supervised by Salinity Officers, in each of the I5 was confirmed at each site, the assessor would examine
participating Regions (all except Orbost Region, which the wider region for associated discharge.
has negligible salinity). Co-ordination of data collection
was conducted by the author. Geological information Recognizing and Assessing Salinity and aerial photographs were utilized to conduct broad
reconnaissance of the regions to locate apparent
discharge sites. Local landholder responses were sought
on the location of discharge through mailouts, LandCare
There are five major indicators of salinity (see Appendix
I for details) :
groups, and articles in local newspapers. Known I . Vegetation
discharge sites provided training sites for assessors. The 2. Position in the landscape
Department of Conservation & Natural Resources 7
3.
4 .
5.
Surface moisture
Bare soil
Salt stains.
Vegetation was also used to assess the level of salinity at
a site . The three classes of salinity (see below) are based
on known field tolerances of a range of plant species, a
method developed (Matters 1987a) for conditions within
V ictoria.
Soil salinity class
2
3
EC 1:5 (!lScm-1 )
300- 600
600-1 400
> 1400
So il testing was conducted where there was uncertainity
salinity, an effort was made to distinguish it from
primary sites in the field . Primary salinity however may
also have a secondary (induced) component due to land
use since European settlement that has caused an
increase in salinity severity at the site, an expansion of
the original site, or both. Where primary sites have been
reactivated, an estimate of the area of expansion was
made for the purposes of calculating total secondary .
salinity in the region, and in the state.
Undisturbed primary sites are characterised by the
presence of native salt-tolerant species which tend to be
mature, perennial, and halophytic, whereas sites of
induced salinity are colonized by volunteer species
which are usually annuals.
as to what class the site was in, or whether there was In the north-west of the state, the presence of clay
salinity at all. Soil test resu lts at the same site however lunettes--crescentic dunes on the eastern side of lakes or
can vary depending on when the samples are taken. This depressions-is also an indicator of natural salinity.
variation is attributable to leaching and concentration of
salts that occur on a seasonal basis, and between years, The grazing of some primary sites has lead to the
related to rainfall patterns. Plant indicators were found to introduction of volunteer salt-tolerant species and other
be more consistent than soil testing, as they give a weeds, making the distinction between primary and
picture of the range of salinity conditions experienced at secondary salinity difficult in these cases.
a site .
The Mapping Procedure
Because of the small size of most of the discharge sites
(50% are less than 2 ha), the standard scale adopted fo r
record ing data was 1 :25 000. For most areas of the state,
aerial photography and topographical bases are available
at this scale. Sites were drafted from the aerial photos
onto copies of the 1 :25 000 bases. Areas were measured
using digital planimeter, digitizer, or dot grid.
Sites have also been digitized onto the CNR GIS
(Geographic Information System) to enable the
discharge mapping to be overlaid with other data, and to
be displayed at a range of scales fo r specified areas. The
full Australian Map Grid Reference of six-digit Easting
and seven-digit N orthing was calculated for each site to
enable small-scale (less than 1:250 000) map work to
also be performed using GIS .
RESULTS
Dryland Salinity in Victoria
The total area of secondary dry land salinity in Victoria is
around 120 000 hectares. This figure consists of
85 000 ha that have been mapped, and an additional
35 000 ha known to occur but not yet documented. This
result is slightly above the estimated figure of
100 000 ha (using data collated from regional sources at
the beginning of the project) and compares to the
estimate for irrigation salinity of approximately 140 000
hectares (Government of Victoria 1988). The salinity
area is 1.0% of the total cleared or naturally treeless,
non-irrigation, non-urban land (also referred to as
dryland agricultural area) in the state. The results are
presented by salinity region or plan area in Table 2 (see
also Map 1 ). The data in Table 2 does not contain all the
salinity in the state as some parts of the state have not
been included in plans. The results in Table 3 give a
Determining the Origin of Salinity more accurate picture of statewide secondary salinity.
As the aim of the project was to document secondary The mapping project has confirmed or exceeded original
8 Department of Conservation & Natural Resources
estimates within each of the former CNR Regions (refer both of which were recorded.
Table 3 and Map 2). In most cases the area was greater
than originally believed due to : The Victorian Dryland Salinity Database
I.
2.
3.
4.
inclusion of low level salt-affected land in this
mapping project, which is not as visually apparent
as the higher classes, and has tended to be
overlooked in previous surveys;
discovery of previously unknown discharge sites;
the process of committing the known sites to maps
revealed more salinity than previously had been
thought to exist.
lack of ability by some of the original assessors to
accurately estimate size. All areas in the Victorian
The database (Allan 1993) consists of every mapped
discharge site in the State. The record for each site
includes a unique number, an area in hectares, an Easting
and a Northing. Depending on the level of assessment,
there may also be a salinity class. Sites that were
assessed as being predominantly (>95%) or totally
natural, or due to irrigation or seepage from a water
supply channel, have been recorded, but are not included
on the database.
Dryland Salinity Database (Allan 1993) have been Five thousand discharge sites, encompassing a total area
measured from maps. of 85 000 ha, have been located. Three thousand of the
sites are recorded onto I :25 000 mapsheets, three
The most startling result was for Bendigo CNR Region hundred in number; the remainder are recorded only as
where a six-fold difference exists between the original point data.
estimate (5000 ha) and the actual result (30 000 ha).
The sites range in size from less than one hectare, up to
The apparent over-estimate in 1989 prior to the two thousand hectares. However, fifty percent of the
commencement of assessment, for Horsham and sites are less than two hectares in size, and only one-
Geelong Regions, is due in part to the differentiation quarter of the sites are greater than 25 hectares. See
between sites of primary and sites of secondary origin, Tables 4 and 5 for analyses of sites in the database.
Table 2: Secondary Dryland Salinity by Salinity Plan Region (areas in hectares)
Salinity Plan Region Secondary Salting Secondary Salting as
in Dryland Agricultural Percentage ofDryland
Areas Agricultural Area 1
Avoca 5 570 0.9
Avon-Richardson 10 500 3.6
Campaspe 3 200 0.9 Corangamite 10 900 0.7 Glenelg 20 ooo4 1.0
Goulbum 3 500 0.3 Lake Wellington 10 000 4.5
Loddon 7 400 1.0
Mallee 15 ooo4 0.6 North-East 250 <0.1 South-East2 10 000 0.6 Wimmera3 13 000 1.0
Dryland agricultural areas derived using CNR GIS data
2 Excluding Lake Wellington catchment
3 Excluding Avon-Richardson catchment
4 Not a final figure- accurate mapping is incomplete (Glenelg) or is out of date (Mallee)
Department of Conservation & Natural Resources 9
Table 3: Secondary Dryland Salinity in Victoria by CNR Region (areas in hectares)
CNRRegion Area estimated at June I989 Area mapped at June I993 Estimated total Alexandra 900 900 1 800 Baimsdale 376 543 1 000 Ballarat 5 500 5 5I5 5 515 Benalla 2 600 2 600 5 200 Bendigo 5 500 30 oooi 30 000 Central Gippsland IO I20 I5 8602 20 000 Co lac 7 500 8 650 8 650 Dandenong I 000 2 000 2 000 Gee long 6 000 I 22I I 221 Horsham 20 000 9 000 9 000 Melbourne - I70 300 Mil dura I2 000 5 000 I5 000 North-East 90 200 250 Portland I3 000 0 I6 000 Yarram 600 700 2 000
1 This figure includes 3500 ha of salinity mapped on non-agricultural land, which is predominantly wetland around Lake Buloke.
2 This figure is derived from calculated areas for the Lake Wellington catchment (Lake Wellington SMP Technical Support Group 199I) as follows:
Dry land Wetland
Private land 12 000 3 980
• Public land
540 4 I45
Table 4. Size Analysis on Discharge Sites in the Victorian Dryland Salinity Database
Dryland Salinity Plan No. of Sites Average Size Minimum Size Maximum Size
Region (see Map 1) (ha) (ha) (ha)
Avoca 63 84.1 0.1 985.6
A von Richardson 57 I94.1 1.0 2000.0
Campaspe 143 14.9 0.6 108.1
Corangamite 847 13.3 0.1 935.4
Glenelg 436 8.3 0.1 I89.0
Goulburn 449 I O.I 0.1 I45.6
Lake Wellington 116 139.1 0.1 1552.4
Loddon II5 62.9 0.2 761.2
North-east 25 3.9 O.I 29.4
Phillip Island 28 44.9 2.7 428.8
South-east 1 I35 8.8 O.I I58.5
West ofWimmera 2 54 25.2 0.2 222.0
Wimmera catchment 546 I6.8 O.I 329.6
Excludes Lake Wellington and Phillip Island data. See separate listings.
2 The area west of Wimmera catchment is not incl uded in a plan.
Note: Detail mapping necessary for the above analysis was not available for sites in the Mallee. The data presented
here for Glenelg only includes sites that have been mapped, and these occur in the north-east corner of the Region.
10 Department of Conservation & Natural Resources
Table 5: Size distribution of discharge sites in the quantified (and qualified) at regular intervals.
Database
Size
category (ha)
::;1
1 - 10
10- 100
> 100
Percentage of sites
(rounded to nearest 5%)
20
50
25
5
It is likely that rates will vary with geology, topography,
history of clearing, and land-use.
Salinity Classes
Salinity class has been recorded for 57% of mapped
sites. Comparisons based on class, between sites and
regions, can be conducted to a limited degree as many
At this stage 75% (by area) of total estimated dryland factors, including geology, land-use, climate and season,
salinity in the State has been mapped. Regions with a affect the level of salinity
large area to survey and a large estimate of salinity
(Mallee and Glenelg) are yet to complete discharge In the Corangamite Region mapping exercise, soil
assessment. salinity levels, sampled in summer, were higher than
expected for the indicator plants present, when compared
Even in those Regions where assessment has been to the three ISCON salinity classes and recorded
substantially completed, further sites may be located in tolerance levels of the plants. This phenomenom is due
the future . The database will need to be updated to the plants being able to tolerate the high salinity levels
regularly for this reason, and also because of the active recorded at the time of sampling for limited periods
nature of many discharge sites. only. The plants that establish and persist reflect the
general salinity levels experienced at a site; the soil
The map references of each site on the database, has
been combined with a broad analysis of salinity in
Glenelg Region, to produce Map 3 at a scale of
1:1,000,000 using GIS.
Rate of Spread of Dry land Salinity
To date scant data has been available on the annual
samples were giving only a snapshot of conditions
experienced throughout the year.
An Overview of Dry land Salinity Discharge by Salinity Region
Avon-Richardson
percentage increase in dryland salinity across the State. There has been 14 200 ha of discharge mapped, and this
An arbitrary figure of 2% has been used (Govt. Viet. occurs throughout the catchment, concentrated within
1988) as an average Statewide, though in estimates so and beside low-lying areas such as watercourses and
far obtained, the rate at individual sites varies from zero lakes. Three-quarters of the salt-affected land is
to around 15% (Dept. CFL, 1988). agricultural. The remaining quarter (3 500 ha) is around
wetlands.
Salinity area increase was calculated at a number of sites
across a geographical range in the Corangamite Salinity Campaspe
Region, and was found to range from 1.2% to 6.6%, and
gave an average of 2% (Corangamite Salinity Forum Major outbreaks of salinity are found along Mt Camel
1993). Range and at Knowsley (north and west of Heathcote
respectively), Elphinstone, west of Tooboorac, and the
In order to develop a range of reliable data from which sedimentary country south-east of Bendigo, including
salinity growth rates could be calculated, a series of Axe Creek catchment.
monitoring reference areas is being established across
the state. Representative discharge areas are pegged, and The area of salinity mapped totals 3200 ha, though an
soil and plant information recorded. This information additional 780 ha is estimated to be affected.
will be used as a baseline from which changes can be
Department of Conservation & Natural Resources 13
Corangamite Due to the steep dissection of land in the Upper
Goulburn, discharge sites are relatively small, and the
Of the 16 200 ha of sal inity mapped, 11 000 is total area affected is limited, however the greater impact
considered to be secondary salinity. The secondary is of discharge directly into streams.
salinity is predominantly found in the Heytesbury
settlement, Upper Woady Yaloak, and the Bamgamie- Loddon-Avoca Meredith area, on the basalt plains, in the Upper
Maribyrnong catchment, at Moriac and Barwon Downs.
Detail on the mapping results is reported in Scott (1992)
and Muske ( 1992). Mapping has yet to be completed for
Discharge in these two catchments total 13 000 ha, and
this is concentrated in the southern, upland areas.
Localities with significant levels of salt-affected land are
the areas south of Ballarat, and the southern Burkes Flat, Natte Yallock, Lexton, Ravenswood,
Corangarnite. Nuggetty (near Maldon), Leichhardt, Woodstock,
Eddington, Dunluce, and north of Campbelltown. In the
The remaining 5000 ha is natural salinity and this is
distributed around Lake Corangamite (Beeac and Leslie
Manor locales), Lake Murdeduke, Bellarine Peninsula,
and the coast between Geelong and Point Cook.
Glenelg
Approximately 20 000 ha of salinity has been calculated
as occurring in Glenelg Region. This is based on
extrapolation from existing mapping.
Major outbreaks occur in the Dundas Tablelands, the
Willaura Plains and Victoria Valley.
Discharge occurs in almost every gully and creek line on
the Dundas Tablelands.
The alluvial and basalt areas of the Willaura Plains, to
the southeast of the Grampians, is an area in the region
where detailed mapping has been conducted, and 3600
ha of salinity recorded. Salinity presents a threat to many
wetlands on the basalt plains.
Goulbum-Broken
northern Loddon, major outbreaks occur at Kamarooka
and Bears Lagoon.
Mallee
A total of approximately 105 000 ha of discharge has
been calculated as occurring in the Mallee. This figure is
derived from salinity mapping for the area conducted in
the late 1960s (Rowan 1971 ). Of this total, roughly
90 000 ha is termed natural and was present at the time
of European settlement. Major discharge features
associated with natural salinity include Pink Lakes, Raak
Plains, Lake Tyrell, Noora Depression and Kowangee.
The estimated 15 000 ha of secondary (induced) salinity
has been brought about by low water-using agricultural
practices. Twelve thousand hectares of secondary
salinity is due to rises in the regional water-table, and the
remaining 3000 ha is discharging on dunes and near
water-supply channels from local groundwater systems.
There is a program currently in operation that replaces
the open, earthen water-supply channels with concrete
pipe, which will minimize discharge from this source.
Control of salinity from other sources is concentrating
Intensive mapping exercises have located 3500 ha of on improving water use over a large part of the Mallee
discharge in this region . Around Benalla, discharge is landscape through strategic tree planting, sowing lucerne
concentrated around the northern and western flanks of and other perennial pastures, and minimizing fallow.
the Strathbogie Uplands and the roll ing hills north of
Violet Town. Further south, discharge is concentrated in
the Majors, Gardiner, Whiteheads and Hughes Creek
catchments, and these have been assigned priority for
treatment in the Salinity Management Plan (Goulburn
Broken Salinity Pilot Program Advisory Council 1989).
14 Department of Conservation & Natural Resources
North-east
Salinity has been found in the Springhurst and Byawatha
areas (north-east of Wangaratta), and at Middle Indigo
(east of Chiltern). Further investigation is to be
conducted in the King River Valley, where salinity is
thought to be a larger problem than currently recognised.
South-east
Twenty thousand hectares of dryland salinity have been
recorded in this region.
The worst affected areas are at Phillip Island, and the
hinterland of Lakes Wellington and Victoria (in the
western Gippsland Lakes).
Salinity on Phillip Island is widespread, with discharge
occurring in many of the drainage lines. There is a total
of 1200 hectares of salinity which represents 12% of the
island.
The hinterland of Lake Wellington carries significant
areas of wetland which has high conservation value,
particularly for waterbirds. However these wetlands are
threatened by increasing salinity levels (Nash 1991).
The causes of salinity in the hinterland are complex.
There would have been lake edge salinity before
European settlement (estimated at 5% of the current
area). After the permanent opening of Lakes Entrance,
levels in the lakes dropped, and salinity increased.
Salinity has also come about through tree-clearing and
grazing/cropping regimes in the upper catchment.
To the north-west of Lake Wellington are located the
Nambrok-Denison and Macalister Irrigation Districts,
and a proportion of the water applied on these areas
reaches the watertable and plays a role in dryland
salinity lower in the catchment, around the Lake.
Wimmera
Over 18 000 ha of dry land salinity have been recorded in
this region. Most of the class 3 (high-severe level)
salinity occurs along the Wimmera River south of Lake
Hindmarsh, and most of this is natural discharge from
the regional Parilla Sand aquifer. This system continues
along a string of lakes west of Mt Arapiles. Natural
salinity is estimated to total 7000 hectares.
Small amounts of salting occur m restricted irrigation
districts near Horsham. Channel seepage from the
Wimrnera-Mallee Stock and Domestic Water Supply
System occurs at various locations throughout the
Region.
Salinity Management Plans
The information reported in this section and Tables 2
and 3 has been obtained from regional staff, in particular
the assessors, in each of the relevant CNR offices (see
acknowledgement list) . Further information can be
obtained by consulting the salinity management plan for
any salinity region. The plans are available through
CNR.
CONCLUSIONS
The extent of dryland salinity is much larger than
previously recorded. The difference between the fmal
figure of 120 000 ha, and the previously published figure
of 55 000 ha (Government of Victoria 1988), does not
represent the magnitude of increase in salinity area over
that period, but illustrates the effort invested in recording
salinity.
There is no doubt that there are some discharge sites that
have been overlooked during the surveys, but this is
believed to be equivalent to a very small proportion of
the total area mapped statewide. Updating of the
database will be an ongoing task.
RECOMMENDATIONS
It is necessary to complete discharge mapping in
Glenelg, and update the Mallee, in order to complete
discharge mapping for the state, in line with aims and
targets of the Statewide Dryland Salinity Assessment
Project.
Reference areas, to monitor salinity, have been
established at a number of discharge sites in the Loddon,
Campaspe, Corangamite, and Wimmera Regions. The
sites have been selected on the basis of representing the
broad range of groundwater systems, rainfall, and land-
Department of Conservation & Natural Resources 15
use. This project should continue to complete the
network within these Regions, and across the state. Cope, F. (1958) Catchment salting in Victoria. Soil
Reassessment of the salinity reference areas should be Conservation Authority, Victoria, Technical Series
conducted at 2-yearly intervals. 1.
ACKNOWLEDGEMENTS Corangamite Salinity Forum (1993) Restoring the
balance. A strategy for managing salinity m the
The salinity field mappers: Corangamite Salinity Region. CNR, Colac.
H . Anderson- mid Wimrnera, C. Barry-Bengworden, Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and
M. Blurnl-Dandenong CNR Region, P. Codd, J. Duff, Leigh, J.H. (1981) Plants of Western New South
J. Modra, E. Muske and K. White--Colac CNR Region, Wales. Soil Conservation Service ofNSW.
R. Durie--Bendigo CNR Region, M. McKenzie,
G. M oore & C. Sturmfels- Ararat district, Department of Conservation, Forests and Lands (1988)
J. M atters- Lake Wellington hinterland, Salinity control strategy. Ballarat Region ( unpubl.)
J. Rowan- Mallee, K. Scott--Geelong CNR Region,
G. Slater- N orth-east, J. Smith & B. Garrett-Benalla Duff, J. S. (1983) Soil salting in the Lake Corangamite
CNR Region, G. Stockfeld- northern outskirts of region of south-western Victoria. M.Ag.Sc. (thesis),
M elbourne, D . Strudwick & M. Wilson-Lower Uni. ofMelbourne.
Wimmera, G. Trease- Yarrarn CNR Region.
The following CNR staff for general assistance: P. Codd,
D . Herpich, L. Hodgson, A. Kennelly, T. Lewis, J.
M cRoberts, P . Ockenden, J. O'Neill, N. Penrose, B.
Radford, C. Sturmfels.
Colleagues at CLPR: C. Clifton, C. Day, S. Hill,
T. Kevin, S. Ryan & D. Strudwick, fo r advice
throughout project, and reviewing this report. P. Cook,
W. Harvey, R. Clark & L. Wieneke, for technical
assistance. J. Bowman and K. Ferrari for word
Goulburn-Broken Salinity Pilot Program Advisory
Council (1989) Goulburn dryland salinity
management plan.
Government of Victoria (1988) Salt Action:Joint Action,
Victoria's strategy for managing land and water
salinity.
Lake Wellington Salinity Management Plan Technical
Support Group (1991) The Lake Wellington
catchment salinity management plan, draft outline
processing assistance. report.
Special thank you to James Matters for training in the Matters, J.M. (1987a) Dryland salinity component
mapping method, and for imparting his extensive criteria and methodology of assessment. Land
knowledge on salt-indicator plants. Protection Division, Viet. (unpubl.)
REFERENCES Matters, J.M. (1987b) Metliod of assessment of dryland
ACIL (1 983) Causes, extent and effect of salinity m
Victoria ACIL Australia Pty. Ltd .
Allan, M.J. (1993 ) Victorian dryland salinity database.
CLPR, CNR, Bendigo.
Bridgewater, P.B., Rosser, C. and de Corona, A. (1981 )
The Saltmarsh Plants of Southern Australia.
Monash University, Melbourne.
16 Department of Conservation & Natural Resources
salinity. Land Protection Division, Viet. (unpubl.)
Matters, J.M. and Boruvka, V. (1987) Field Guide to
Plants Associated with Saline Soils of Victoria. Dept.
Conservation Forests and Lands.
Matters, J.M. and Bozon, J. (1989)Spotting Soil Salting.
DC FL.
Moore, G. (1984) A survey of dryland salting in the
Willaura district. SCA, Victoria (unpubl.)
Muske, E. (1992) Saline discharge in the Corangamite
Salinity Region. Background report no. 2, Colac
Region, CNR.
Nash, N. (1991) Lake Wellington catchment wetlands
salinity study. Central Gippsland Region, Dept.
Conservation and Environment.
Ross, J.H. (1990) A census of the vascular plants of
Victoria (Third Edition). National Herbarium of
Victoria, Dept. of Conservation, Forests and Lands.
Rowan, J.N. (1971) Salting on dryland farms in north
western Victoria. Soil Conservation Authority.
Scott, K. (1992) Salinity discharge mapping for the
eastern section r of Corangamite Salinity Region.
Background report no. 1, Geelong Region, CNR.
Soil Conservation Authority (1978) Dryland salting in
Victoria, Australia.
Soil Conservation Authority (1983) Dryland salinity in
Victoria. Evidence for parliamentary enquiry.
Speedie, T. W. and Gibbons, F. R. (1984) Dryland
salinity in the Victorian Mallee. Soil Conservation
Authority.
Sturmfels, C. (1982) Survey of saltland in the Ararat
district, Victoria. Soil Conservation Authority,
Victoria (unpubl.)
White, K.G. (1981) Plants as indicators of dryland soil
salinity. Soil Conservation Authority ( unpubl. ).
Willis, J. H. (1970) A Handbook of Plants in Victoria:
Vol. I (Ferns, Conifers and Monocotyledons)
Melbourne University Press.
Willis, J.H. (1972, publ. 1973)A Handbook to Plants in
Victoria: Vol. II.
University Press.
(Dicotyledons). Melbourne
Willis, J.H. ( 1988) A Handbook to Plants in Victoria -
Supplement. Melbourne University Press.
Working Party on Dryland Salinity (1982) Salinity of
non-irrigated land in Australia. SCA, Victoria, for
the Standing Committee on Soil Conservation.
Department of Conservation & Natural Resources 17
APPENDIX 1. RECOGNISING AND CONFIRMING SALINITY
1 Major Indicators
The following characteristics are major indicators of
salinity.
1.1 Vegetative indicators
1.1.1 Salt-tolerant species
The most common criterion for recognising salinity was
1.1.3 The plant community
With increasing salinity a previously non-saline
vegetation community will change in composition from
one containing salt-sensitive species to a community
containing an increasing number and variety of salt
tolerant species. . In pasture and natural vegetation
associations, a change would be evident over a number
of seasons, to a dominance by annuals (White 1981;
Matters 1987a). White (1981) also found in his study of
saline discharge sites in the Corangamite region of
Victoria, that the number of grasses and clovers
decreased with increasing salinity, while species in the
rush and sedge groups thrived. the presence of known salt-tolerant species (listed in
Appendix 2). The presence of two to three known salt
tolerant species with any of the physical indicators 1.2 (listed later) generally confirmed salinity without the
Groundwater
need to take soil samples. Free water or dampness at the ground surface
(particularly in summer) may be due to groundwater
In the absence of known salt-tolerant species it was discharge, though of course recent rain and waterlogging
necessary to examine the plants present for (see later section on waterlogging) are also possible
morphological evidence of salt-tolerance, such as causes. The free water was analysed for salt using a field
stunting, thickening of the cuticle, reduction of leaf electroconductivity (E.C.) meter.
hairiness, short internode length, semi-succulence in
leaves, and reddening of the plant.
1.1.2 Salt sensitive species
Salt-sensitive species (see Appendix 3), including some
crop and pasture plants, were used as indicators of
increasing salinity in the absence of salt-tolerant plants,
as the following changes are observed in populations of
salt-sensitive plants (Matters 1987a): much slower
growth rate, incomplete life cycle, diminished
abundance, depressed health (commonly apparent by
characteristic yellowing and stunting of crop or pasture
species), greater susceptibility to disease, decreased seed
viability, decreased germination rate.
The absence of salt-sensitive species, for example
subterranean clovers, otherwise present in the near
1.3 Bare soil
The soil may be bare due to death of the original salt
sensitive native vegetation, crop or pasture, or at the
other extreme, the soil salinity may be too high for any
plants to tolerate. Once bare, the soil is prone to erosion,
and salt accumulates at a faster rate, as higher
evaporation rates of groundwater occur than when the
soil is vegetated. A pattern of baring begins in low points
in the microtopography, these being marginally but
critically closer to the watertable. As part of the process
of degradation salt-tolerant species may then establish,
though this is dependent on a suitable seed source in the
region.
1.4 Salt
vicinity, is an indicator of salinity. This was an Salt was sometimes observable (more so on bare soil) as
important diagnostic tool, particularly where the only a white stain, or actual salt crystals (an encrustation).
salt-tolerant species present are also capable of growing This is one of the more definitive indications of salinity.
in non-saline environments.
18 Department of Conservation & Natural Resources
1.5 Position in the landscape
Local groundwater aquifer systems have watertables
confusion was avoided to some extent by leaving
assessment to late spring, summer or early autumn, when
rainfall is generally lower.
which generally follow the surface topography. Regional
groundwater' aquifer systems have flat or gently sloping 3.2 Plants outside documented range
watertables and extend under a number of surface water
catchments. Discharge within both systems tends to
appear at topographically low sites on flats, drainage
lines, lake margins, depressions and stream banks where
the surface intersects the watertable. Local systems may
also discharge on hillsides from perched watertables
caused by an aquifer overlaying a confining (usually
clay) layer. Break-of-slope describes a change in surface
gradient correlated with an increase in clay thickness
causing groundwater to 'slow down' and consequently
discharge.
2 Secondary Indicators
In general, the distribution maps in the Spotting Soil
Salting booklet (Matters and Bozon 1989) and Willis
(1970 and 1972) can be used as an aid to plant
identification. However, by the very nature of induced
salinity, which is an unnatural environmental situation
that is worsening, a salt indicator plant (especially an
introduced species) may be found outside the previously
recorded range. In such cases a record, including a
pressed specimen, was made and the State Herbarium
and the SDSA Officer notified.
4 Physical Factors Affecting Assessment
Less common indicators of soil salinity include tree 4.1 health decline and soil blackening.
Masking
2.1 Tree health Cultivation, slashing or harvesting can conceal the
presence of salinity at a site.
Dieback or death may be due to salinity, though other In a suspected case of masking, a return visit was paid
factors can cause tree decline and this was a when the next crop or pasture had developed
consideration during field assessment. For this reason
tree decline is used only as a secondary indicator.
2.2 Soil blackening
Soils low in phosphorus and nitrogen, and saline affected
can sometimes be recognized by a blackening due to the
dispersion and dark coloration of the organic matter of
the soil (Matters 1987a). This phenomenon was not
encountered during this study.
3 Limitations of Plants as Indicators
3.1 Salt-sensitive plants in discharge sites
4.2 Waterlogging
It is necessary to distinguish waterlogged sites from
discharge of saline groundwater. Waterlogging is the
ponding of surface water due to slow or inadequate
drainage. Waterlogging is a serious problem in itself,
and may exacerbate salinity discharge. Plants adapted to
waterlogging include sedges and rushes.
Mild salinity was recorded in closed depressions in the
Wimmera Catchment well above the watertable, through
a process whereby salt in the surface water is
concentrated by high evaporation rates (D. Strudwick,
CLPR, CNR, pers. comm.). This was distinguishable
Confusion can arise when salt sensitive species such as from groundwater driven salinity only where the depth to
Subterranean Clover or Yorkshire Fog Grass occur in watertable was known.
what appears to be a discharge site. This may be due to
leaching of salt during periods of high rainfall, and is If surface water was present, a salinity test was
more likely to happen during winter when annual plants performed, and the usual criteria (see Major Indicators)
in particular can complete their life-cycle before salt applied, in order to determine if dryland salinity was
levels in the soil rise again as summer progresses. This occurring.
Department of Conservation & Natural Resources 19
4.3 Incipient salting
Low levels of surface salinity can be due to a high
watertable which is close to, but not actually discharging
at, the soil surface, and which is within the reach of plant
roots (known as incipient salting and included in the
mapping) . Low incipient-type levels of salinity can also
result from leaching of salt down the soil profile after
rain; this process can also reduce the level of apparent
salinity at the soil surface to a lower class (e.g. from S3
to S2, or from S2 to S 1 ).
20 Department of Conservation & Natural Resources
APPENDIX2. SALTTOLERANT PLANTS
Below is a list of plant species compiled during the
ISCON project and found in association with saline soils
in Victoria. The salinity classes of only · those plants
featured in the handbooks (Matters and Boruvka 1987;
Matters and Bozon 1989) are known.
Taxonomy has been updated using Willis (1970, 1973,
Herbs
(?) Angianthus preissianus
* (?) Aptenia cordifolia
* (?) Carpobrotus aequilaterus
* (A) Cotula bipinnata
(AlP) Cotula coronopifolia
(P) Disphyma crassifolium
ssp. clavellatum
(?) Dysphania glomulifera
(?) Einadia trigonos
(?) Lawrencia glomerata
* (A) Lotus subbiflorus
* (?) Medicago minima
(?) Mesembryanthemum crystal/inurn
(A) Myosurus minimus
(?) Osteocarpum salsuginosum
* (P) Plantago coronopus
(P) Samolus repens
(P) Sarcocornia quinquejlora
* (?) Sarcozona praecox
(?) Selliera radicans
(P) Spergularia marina
* (?) Spergularia media
*(A/B) Spergularia rubra
(P) Suaeda australis
* (?) Trifolium arvense
* (P) Trifolium fragiferum
* Trifolium campestre
Zygophyllum crenatum
(A) Zygophyllum iodocarpum
1988), Cunningham eta/ (1981), and Ross (1990).
Life Cycle:
*
A- Annual
B- Biennial
P - Perennial
? -not known
Exotic species
Salt Angianthus
Heart Leaf Iceplant
Angled Pigface
Ferny Cotula
Water Buttons
Rounded Noon-Flower
Red Crumbweed
Lax Goosefoot
Clustered Lawrencia
Hairy Bird's-foot Trefoil
Little Medic
Ice Plant
Mousetail
'Bonefruit
Buck's-Hom Plantain
Creeping Brookweed
Beaded Glasswort
Sarcozona
Selliera (Swamp Weed)
Salt Sand-spurrey
Coast Sand-spurrey
Red Sandspurrey
Austral Seablite
Hare's-foot Clover
Strawberry Clover
Hop Clover
Notched Twin-leaf
Violet Twin-leaf
Department of Conservation & Natural Resources 21
Grasses
* (?) Aira caryophyllea Silvery Hair-grass
(A) Agrostis avenacea Blown Grass
(?) Bothriochloa decipiens Pitted Blue Grass
* (A) Briza maxima Large Quaking Grass
* (A) Briza minor Lesser Quaking Grass
* (A) Bromus rubens Red Brome
* (P) Chloris gayana Rhodes Grass
(AlP) Chloris truncata Windmill Grass
* (A) Critesion marinum Sea Barley Grass
(P) Cynodon dactylon Couch
(P) Danthonia eriantha Wallaby Grass
(B!P) Diplachne fusca Brown Beetle-grass
(P) Distich/is dischtophylla Australian Salt Grass
(P) Eragrostis australasia Cane Grass
(P) Eragrostis setifolia Bristly Love-grass
* (A) Hainardia cylindrica Common Barb-grass
* (A) Lolium rigidum Wimmera Rye-grass
* (P) Lophopyrum elongatum Tall Wheat Grass
* (A) Parapholis incurva Coast Barb-grass
* (A) Parapholis strigosa Slender Barb-grass
* (A) Poa annua Annual Meadow-grass
* (P) Poa bulbosa Bulbous Meadow-grass
* (A) Polypogon monspeliensis Annual Beard-grass
(A) Puccinellia stricta Australian Saltrnarsh-Grass
(P) Sporobolus actinocladus Katoora
(P) Sporobolus caroli Yakka Grass
(P) Sporobolus virginicus Salt Couch
(P) Stipa tuckeri Spear-grass
(P) Tripogon loliiformis Rye Beetle-grass
* (A) Vulpia bromoides Squirrel-tail Fescue
Shrubs
(P) Atriplex leptocarpa Slender-fruit Saltbush
(P) Atriplex nummularia Old-man Saltbush
(A) A triplex pseudocampanulata Saltbush
(P) Atriplex vesicaria Bladder Saltbush
(P) Enchylaena tomentosa Ruby Saltbush
(?) Halosarcia pergranulata Samphire
(?) Maireana aphylla Cotton Bush
(?) Maireana brevifolia Short-leaf Bluebush
(?) Maireana georgei Satiny Bluebush
(?) Maireana humillima Bluebush
(P) Melaleuca ericifolia Swamp Paper-bark
(P) Melaleuca halmaturorum Salt Paper-bark
22 Department of Conservation & Natural Resources
(P) Nitraria billardieri Dillon Bush
(?) Osteocarpum acropterum Babbagia
(P) Sclerolaena brachyptera Short-winged Copperburr
(P) Sclerolaena diacantha Grey Copperburr
(P) Sclerolaena divaricata Pale Poverty-bush
(P) Sclerolaena eriacantha Silky Copperburr
(?) Sclerostegia tenuis Slender Glasswort
(?) Sclerostegia triandra Desert Glasswort
Rushes
(?) Jsolepis congrua Club-rush
(A) Isolepis hookeriana Club-rush
* (A) Jsolepis hystrix Awned Club-rush
(A) Isolepis victoriensis Club-rush
* (P) Juncus acutus Spiny Rush
(A) Juncus bufonius Toad Rush
(P) Triglochin striata Streaked Arrowgrass
Department of Conservation & Natural Resources 23
APPENDIX 3. SOME KNOWN SALT SENSITIVE SPECIES
Grasses
* Anthoxanthum odoratum Sweet Vernal-grass
* Briza minor Shivery Grass
Danthonia carphoides Short Wallaby Grass
Deyeuxia sp. Creeping Bent Grass
* Holcus lanatus Yorkshire Fog Grass
Hordeum leporinum Barley Grass
* Latium perenne Perennial Rye Grass
* Romulea rosea Onion Grass
Themeda triandra Kangaroo Grass
Rushes
* Juncus articulatus Jointed Rush
Juncus planifolius Broad-Leaf Rush
Juncus subsecundus Finger Rush
Herbs
* Arctotheca calendula Capeweed
Erodium sp. Heron's-bill
* Leontodon taraxacoides Hairy Hawkbit
Spergularia diandra Small Sandspurrey
* Trifolium subterraneum Subterranean Clover
* Trifolium dubium Suckling Clover
* Trifolium tomentosum Woolly Clover
24 Department of Conservation & Natural Resources