Soil

Ind

icat

ors

of Q

uee

nsla

nd W

etla

nds Lake Wyara

Study AreaLake Wyara is located in Currawinya National Park, approximately 120 kmsouth west of Eulo, South-West Queensland.

The area is an aggregation of large and small ephemeral lakes, claypans and drainage depressions1. Lake Numalla is part of the Currawinya Lakes, which are on the Ramsar List of Wetlands of International Importance.

At the time of sampling the lake was dry. Lake Wyara is an example of a semi-arid saline lake in the Mulga Lands Bioregion

Climate2

0

100

200

300

400

500

600

700

800

900

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonth

Rai

nfal

l-Eva

pora

tion

(mm

)

0

5

10

15

20

25

30

35

40

Tem

pera

ture

(Deg

.C)

Rain Evap

Temp (min) Temp (max)

The study area is situated within a semi-arid climatic region with no distinct wet and dry season. Evaporation exceeds rainfall in every month. The average annual rainfall for the area is 271 mm.

Landform and Inundation

Shallow salt lake on gently undulating sand plainsSaline permanently inundated lake from overland flow

Soils3 Hydrosols and Kandosols

Vegetation4 Halosarcia spp. open succulent shrubland on alluvium (RE 6.3.10)6.3.10)

Geology5 Quaternary alluvium

Disturbance No effective disturbance except grazing by hoofed animals

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Location GDA94 • MGA Coordinates : 230071 E, �817384 N, Zone 55 • Lat/Long : -28.74273 S, 144.23�05 E

Landscape Diagram

Site 4

Saturated zone

Site 1

Outer zone

Site 2Site 3

Transition zone

Salt crystals on soil surface 700m

Footslope of first lunette

Complex of lunettes moving out of lakeSparse shrubland and bead weedDry salt lake

Sand ridge

Soil ProfilesSite 158Site 157Site 156Site 155

0.02 mA1

0.05 m

0.1 m0.13 m

0.2 m

A21

B?

B?

0.3 m

0.� m

B?

B?

B?

B?

0.01 mA11

0.1 m

A12

0.55 m

0.9 m

B21

B22

0.08 mA

0.15 m2A11

0.4 m

0.5 m

2A12

2C

0.8 m

2C

0.1 m

A1

0.5 m

0.� m

A2e

0.8 m

0.9 m

2A1

2A3

2B2

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Soil Indicators Present (within 0.3 m of surface)

Indicator� Site 155 Site 156Organic materials and organic carbon (OC)*

No organic materials OC: 1.98%

No organic materials OC: 0.23%

Matrix colour Greenish grey Pinkish grey to greenish grey

Chroma (thickness of layer)**

Present (0.25 m� Present (0.3 m�

Mottles and Segregations Common <5 mm distinct yellow mottles Many 5-15 mm prominent red mottles Few 5-15 mm prominent yellow mottles Few 5-15 mm distinct brown mottles

Not present

Depth to groundwater 0.� m Not present

Ferruginous root channel and pore linings

Not present Present

pH*7 Strongly alkaline Strongly alkaline

Texture Light clay Clay loam to light clay

Acid sulfate material Present Not present

Electrical Conductivity (EC)7

Brine (Seawater� Highly saline

Indicator� Site 157 Site 158Organic materials and organic carbon (OC)*

No organic materials OC: 0.14%

No organic materials OC: 0.09%

Matrix colour Greyish brown to grey Light grey

Chroma (thickness of layer)**

Present (0.3 m� Present (0.2 m�

Mottles and Segregations Very few <5 mm faint brown mottles Very few <2 mm saline crystals

Not present

Depth to groundwater Not present Not present

Ferruginous root channel and pore linings

Not present Not present

pH*7 Strongly alkaline Strongly alkaline

Texture Loamy sand to light clay Sand

Acid sulfate material Not present Not present

Electrical Conductivity (EC)7

Moderately saline Non saline

*Organic carbon % (Dumas method) and pH taken from surface (0-0.1 m) **Chroma value is less than or equal to 2

Summary of Field ObservationsOrganic carbon content increases moving into the saturated zone, whilst there is no visible

accumulation of plant materials this can be attributed to the presence of microscopic algaePresence of faint, distinct and prominent mottling indicative of water fluctuation throughout the

soil profile in the saturated and transition zoneGley colours (Figure 1) and sulfidic materials confirmed by laboratory testing indicate a permanently

reduced environment in the saturated zoneThe average pH in the saturated zone is mildly alkaline however there is a layer (between 0.15 and

0.25 m) where the pH is strongly acidic, this could be from the oxidation of sulfidic materials

•

•

•

•

Figure 1. Gley soil colours

When a soil is exposed to an anaerobic environment ferric iron (Fe III) in the soil is quickly reduced to the colourless and

mobile ferrous Iron (Fe II)

This gives the soil a characteristic grey/green/blue colour called “gley”

Soil Indicators of Queensland WetlandsSo

il M

orph

olog

y

Site

155

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

Su

lfidi

c, H

yper

salic

Hyd

roso

lLa

ndfo

rm E

lem

ent

Play

aM

orph

olog

ical

Typ

e Fl

at

Hor

izon

Dep

th (

m)

Boun

dary

Text

ure

Colo

urM

ottl

esCo

arse

Fr

agm

ents

Stru

ctur

eSe

greg

atio

nsCo

nsis

tenc

e

A10

to .

02 s

harp

to

light

cla

yye

llow

ish

brow

n (1

0YR5

4�

none

none

mas

sive

none

-

A21

.02

to .

05-

light

cla

ybr

own

(10Y

R53�

co

mm

on (

10-2

0%)

fine

(<5

mm

� di

stin

ct y

ello

w

mot

tles

none

mas

sive

none

-

B?.0

5 to

.1-

light

cla

yda

rk g

reen

ish

grey

(10

GY4

1�

none

none

mas

sive

none

-

B?.1

to

.13

-lig

ht c

lay

light

gre

enis

h gr

ey (

10G

Y71�

man

y (2

0-50

%� m

ediu

m

(5-1

5 m

m�

prom

inen

t re

d m

ottl

es,

few

(2-

10%�

m

ediu

m (

5-15

mm

� pr

omin

ent

yello

w m

ottl

es

few

(2-

10%�

an

gula

r qu

artz

sm

all p

ebbl

es

(2-�

mm

�

mas

sive

none

-

B?.1

3 to

.2

-lig

ht c

lay

gree

nish

gre

y (1

0GY�

1�fe

w (

2-10

%� m

ediu

m

(5-1

5 m

m�

dist

inct

bro

wn

mot

tles

none

mas

sive

none

-

B?.2

to

.3-

light

cla

ygr

eeni

sh g

rey

(10G

Y51�

none

few

(2-

10%�

an

gula

r qu

artz

sm

all p

ebbl

es

(2-�

mm

�

mas

sive

none

-

B?.3

to

.�-

light

cla

ylig

ht g

reen

ish

grey

(10

GY7

1�

very

few

(<2

%) fi

ne

(<5

mm

� fa

int

brow

n m

ottl

es

very

few

(<2

%�

angu

lar

quar

tz

smal

l peb

bles

(2

-� m

m�

mas

sive

none

-

B?.�

to

.7-

light

cla

ylig

ht g

reen

ish

grey

(10

GY8

1�

none

none

mas

sive

none

-

Soil Indicators of Queensland Wetlands

Site

156

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

H

aplic

, H

yper

salic

Hyd

roso

lLa

ndfo

rm E

lem

ent

Foot

slop

eM

orph

olog

ical

Typ

e M

idsl

ope

Hor

izon

Dep

th (

m)

Boun

dary

Text

ure

Colo

urM

ottl

esCo

arse

Fra

gmen

tsSt

ruct

ure

Segr

egat

ions

Cons

iste

nce

A10

to .

01 s

harp

to

clay

loam

, sa

ndy

pink

ish

grey

(7

.5YR

�2�

none

none

stro

ng 1

0-20

mm

pl

aty

none

-

A12

.01

to .1

cle

ar t

ocl

ay lo

amgr

ey (

10YR

�1�

none

few

(2-

10%�

sub

angu

lar

quar

tz s

mal

l peb

bles

(2

-� m

m�

mod

erat

e 5-

10 m

m p

laty

com

mon

(10

-20%

) fin

e (<

2 m

m�

ferr

ugin

ous

root

lini

ngs

-

B21

.1 t

o .5

5 g

radu

al t

olig

ht c

lay

light

gre

enis

h gr

ey (

10Y7

1�

none

none

mas

sive

none

-

B22

.55

to .9

light

cla

ygr

eeni

sh g

rey

(10Y

�1�

none

none

mas

sive

none

-

Site

157

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

H

aplic

, H

yper

salic

Hyd

roso

lLa

ndfo

rm E

lem

ent

Lune

tte

Mor

phol

ogic

al T

ype

Sim

ple

slop

eH

oriz

onD

epth

(m

)Bo

unda

ryTe

xtur

eCo

lour

Mot

tles

Coar

se

Frag

men

tsSt

ruct

ure

Segr

egat

ions

Cons

iste

nce

A10

to .

08 a

brup

t to

loam

y sa

ndgr

eyis

h br

own

(2.5

Y52�

no

neno

nem

assi

veno

ne-

2A11

.08

to .1

5 c

lear

to

light

cla

ygr

eyis

h br

own

(2.5

Y52�

ve

ry f

ew (

<2%�

fin

e (<

5 m

m)

fain

t br

own

mot

tles

none

mod

erat

e 5-

10 m

m

suba

ngul

ar b

lock

y

very

few

(<2

%) fi

ne

(<2

mm

� sa

line

crys

tals

-

2A12

.15

to .

4 c

lear

to

light

cla

ylig

ht b

row

nish

gre

y (2

.5Y�

2�no

neno

new

eak

5-10

mm

su

bang

ular

blo

cky

very

few

(<2

%) fi

ne

(<2

mm

� sa

line

crys

tals

-

2C.4

to

.5 c

lear

to

sand

y lig

ht

clay

light

bro

wni

sh g

rey

(2.5

Y�3�

no

neno

nem

assi

veno

ne-

2C.5

to

.8-

clay

loam

light

bro

wni

sh g

rey

(2.5

Y�2�

no

neno

nem

assi

veco

mm

on (

10-2

0%)

fine

(<2

mm

� sa

line

crys

tals

-

Soil Indicators of Queensland Wetlands

Site

158

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

Bl

each

ed,

Mes

otro

phic

, Ye

llow

Kan

doso

lLa

ndfo

rm E

lem

ent

Play

aM

orph

olog

ical

Typ

eFl

at

Hor

izon

Dep

th (

m)

Boun

dary

Text

ure

Colo

urM

ottl

esCo

arse

Fr

agm

ents

Stru

ctur

eSe

greg

atio

nsCo

nsis

tenc

e

A10

to .1

cle

ar t

osa

ndlig

ht b

row

nish

gre

y (2

.5Y�

3�

none

none

sing

le g

rain

none

-

A2e

.1 t

o .5

cle

ar t

osa

ndlig

ht g

rey

(2.5

Y72�

no

neno

nem

assi

veno

ne-

2A1

.5 t

o .�

gra

dual

to

loam

y sa

ndda

rk g

reyi

sh b

row

n (2

.5Y4

3�

none

none

mas

sive

none

-

2A3

.� t

o .8

gra

dual

to

light

san

dy

clay

loam

grey

ish

brow

n (1

0YR5

2�

none

none

mas

sive

none

-

2B2

.8 t

o .9

-cl

ay lo

am,

sand

y-

none

none

mas

sive

none

-

Soil

Chem

istr

y

Site

Dep

th (

m)

pH*

EC dS/m

Cl mg/

kgN

O3-

Nm

g/kg

TC**

%TN

**%

Ca meq

/100

gM

gm

eq/1

00g

Na

meq

/100

gK m

eq/1

00g

ESP

%CE

Cm

eq/1

00g

155

0.00

-0.1

08.

5�2

.511

4000

81.

980.

195.

715.

4115

.�2.

�5�2

.425

0.20

-0.3

0�.

�34

.951

000

110.

520.

0�3.

452.

�217

.32.

8557

.730

0.40

-0.5

08.

131

.945

300

140.

27<0

.03

�.37

3.01

15.2

2.52

58.5

2�

15�

0.00

-0.1

08.

921

3030

09

0.23

<0.0

32.

�51.

974.

381.

0840

11

0.20

-0.3

08.

517

.925

800

50.

19<0

.03

2.�2

2.3�

122.

11�3

.219

0.40

-0.5

08.

�13

.218

300

30.

25<0

.03

2.88

1.89

8.5

1.39

5�.7

15

157

0.00

-0.0

88.

82.

4427

202

0.14

<0.0

31.

850.

380.

530.

4513

.24

0.08

-0.1

58.

73.

5540

00<1

0.21

<0.0

33.

540.

782.

470.

9827

.49

0.20

-0.3

08.

��.

5483

705

0.28

<0.0

3�.

121.

�7.

231.

8742

.517

0.40

-0.5

08.

59.

1412

200

20.

54<0

.03

7.71

1.82

10.4

2.1�

43.3

24

158

0.00

-0.1

09

0.12

853

0.09

<0.0

30.

718

<0.3

10<0

.091

0.11

3<3

0.20

-0.3

08.

�0.

02<2

01

<0.0

5<0

.03

0.87

3<0

.310

<0.0

910.

123

<3

0.40

-0.5

09.

10.

1712

5<1

<0.0

5<0

.03

0.54

7<0

.310

0.11

0.12

3.7

<3

*Aqu

eous

1:5

**To

tal c

arbo

n an

d to

tal n

itro

gen

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s

0

0.1

0.2

0.3

0.4

0.5

0 0.5 1

E C (d/S /m )

Dept

h (m

)

0

0.1

0.2

0.3

0.4

0.5

0 10 20 30 40 50 60

E C (d/S /m )

Dept

h (m

)

0

0.1

0.2

0.3

0.4

0.5

0 5 10 15 20 25

E C (d/S /m )

Dept

h (m

)

0

0.1

0.2

0.3

0.4

0.5

0 5 10 15

E C (d/S /m )

Dept

h (m

)

References1. DEWHA (2008). Australian Wetlands Database. [online]. Available at http://www.environment.gov.au/water/publications/environmental/wetlands/database/ [accessed 21/08/08].

2. Queensland Department of Natural Resources and Water (2008). SILO [online]. Available at http://www.longpaddock.qld.gov.au/silo/ [accessed 5/11/2007].

3. Isbell RF (2002). The Australian Soil Classification. CSIRO Publishing, Collingwood, Victoria, revised edition.

4. EPA (2008) Regional Ecosystems. [online]. Available at http://www.epa.qld.gov.au/nature_conservation/biodiversity/regional_ecosystems/ [accessed 28/06/08].

5. Bureau of Mineral Resources (1971). Eulo: Australia 1:250,000 Geological Series, Bureau of Mineral Resources, Canberra.

6. Bryant KB, Wilson PR, Biggs AJW, Brough DM and Burgess JW (2008). Soil Indicators of Queensland Wetlands: State-wide assessment and methodology. Queensland Department of Natural Resources and Water. Brisbane.

7. Hazelton P and Murphy B (2007). Interpreting Soil Test Results: What do all the numbers mean?. [2nd ed]. CSIRO publishing. Collingwood Victoria.

8. Department of Natural Resources (1997). Salinity Management Handbook. Queensland Department of Natural Resources, Brisbane.

Electrical CondictivityElectrical conductivity (EC� is a measure to describe the salinity, or the presence of soluble salts, of water, a soil water extract or suspension8. Moving along the transect from the saturated zone to the outer zone there is a distinct difference in profiles sampled.

Site 155

Salts are accumulating at the surface

due to an evaporative

concentration

This level of salt

concentration is considered hypersaline

Site 158

Very little salt is observed in the outer zone

Site 157

Salt is being leached through the soil

profile with accumulation

at depth

Site 156

Salts are accumulating at the surface

due to an evaporative

concentrationbut the

effect is less pronounced

9 3 1 1 6 6 2 1 8 0 6 4 3