Soil

Ind

icat

ors

of Q

uee

nsla

nd W

etla

nds

Study AreaLake Wombah is located approximately 50 km east of Hungerford, South-West Queensland, on the NSW/Queensland border.

The lake forms part of the Lake Wombah – Kungie Lake group which is an aggregation of ephemeral to permanent lakes and claypans.

Lake Wombah is an example of a semi-arid floodplain lake in the Mulga Lands Bioregion.

Climate1

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 or dry season. Evaporation exceeds rainfall in every month. The average annual rainfall for the area is 288 mm.

Landform and Inundation

Shallow lake on gently undulating sand plains Permanently inundated lake from overland flow however may become dry in times of prolonged drought

Soils2 Hydrosols and Rudosols

Vegetation3 Halosarcia spp. open succulent shrubland on alluvium (RE 6.3.10)6.3.10)

Geology4 Quaternary alluvium

Disturbance No effective disturbance except grazing by hoofed animals

Lake Wombah

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Location GDA94 • MGA Coordinates : 287027 E, �794351 N, Zone 55 • Lat/Long : -28.9�115 S, 144.81451 E

Landscape Diagram

Saturated zone

Playa lake

Site 170

Outer zone

Site 172

Transition zone

Halophytic species present

Site 171 Deposition from bordering scarpment

90 m

Germination bands at different lake levels

Soil ProfilesSite 172

0.05 mA1

0.4 m

0.9 m

1.0 m

3D

4D

5D

Site 171Site 170

0.02 m

A1

0.3 m

0.4 m

B21

B22

0.01 mA1

0.05 m

1.0 m

0.85 m

1D

2D

3R

0.2 m

0.1 m

B3

C

0.5 m2B

0.3 m

B20.1 m

0.15 m2D1D

Higher organic carbon content, gley colours, low chroma values,

mottling, ferruginous root channel linings, a soil water interface and the presence of sulfidic materials

all indicate that the area is permanently reduced

Lower organic carbon

content, low chroma values, grey

surface colours and

mottling all suggest

area is periodically

reduced

Surface material is deposited by erosion from the

escarpment above the

site

Mottling is the only

wetland soil indicator present

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Soil Indicators Present (within 0.3 m of surface)

Indicator5 Site 170 Site 171 Site 172Organic materials and organic carbon (OC)*

No organic materials OC: 1.29%

No organic materials OC: 0.21%

No organic materials OC: 0.1%

Matrix colour Greyish brown to greenish black

Olive brown to brownish grey

Olive to brown

Chroma (thickness of layer)**

Present (0.3 m� Present (0.2� m� Not present

Mottles and Segregations

Few <5 mm prominent brown mottles Many 5-15 mm prominent brown mottles Many <5 mm distinct brown mottles Common 5-15 mm faint brown mottles Very few <2 mm calcareous soft segregations Very few <2 mm saline crystals

Many <5 mm distinct orange mottles Many 5-15 mm faint brown mottles Few <2 mm saline crystals Very few <2 mm calcareous soft segregations

Few 5-15 mm faint yellow mottles Few <5 mm faint brown mottles Very few <2 mm calcareous soft segregations

Depth to groundwater 0.5 m Not present Not present

Ferruginous root channel and pore linings

Present Not present Not present

pH*� Mildly alkaline Mildly alkaline Strongly alkaline

Texture Silty light clay to light clay Fine sandy clay loam to fine sandy light medium clay

Clayey sand to sandy clay

Acid sulfate material Present Not present Not present

Electrical Conductivity (EC)�

Moderately saline Highly saline Slightly 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 algaeFaint, distinct and prominent mottling (Figure 1) all indicative of water fluctuation at all soil profilesFerruginous root channel linings in the saturated zone (Figure 1� are evidence of plants growing in

saturated conditionsGley colours (Figure 1� and low chroma values suggest a permanently reduced environment in the

saturated zoneSulfidic materials confirmed by laboratory testing in saturated zone indicate a reduced environmentEvaporative profile in transition zone from capillary fringe effect indicated by high EC and presence

of halophytic species Uniform salt profile in saturated zone A thin layer of red or orange soil colours exist as evidence of the oxidation reactions occurring at

the soil water interface in the saturated zone (Figure 1�

•

••

•

••

••

Figure 1. Mottling, ferruginous root channel linings, gleyed soil

colour and a soil water interface in the surface of the

saturated zone

Soil Indicators of Queensland WetlandsSo

il M

orph

olog

y

Site

170

Cl

assi

fica

tion

Au

stra

lian

Soil

Clas

sifi

cati

on

Mot

tled

, 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

ns

A10

to .

02 s

harp

to

silt

y lig

ht c

lay

dark

gre

enis

h bl

ack

(10G

31�

few

(2-

10%)

fine

(<5

mm

) pr

omin

ent

brow

n m

ottl

esno

nem

assi

veve

ry f

ew (

<2%)

fine

(<2

mm

) ca

lcar

eous

so

ft s

egre

gati

ons,

few

(2-

10%)

fine

(<2

mm

) fe

rrug

inou

s ro

ot li

ning

s

B21

.02

to .1

cle

ar t

olig

ht c

lay

grey

(10

YR51

� m

any

(20-

50%�

med

ium

(5-

15 m

m�

prom

inen

t br

own

mot

tles

none

wea

k 2-

5 m

m s

uban

gula

r bl

ocky

very

few

(<2

%) fi

ne (

<2 m

m)

salin

e cr

ysta

ls

B22

.1 t

o .2

cle

ar t

olig

ht c

lay

grey

ish

brow

n (1

0YR5

2�

man

y (2

0-50

%) fi

ne (

<5 m

m)

dist

inct

bro

wn

mot

tles

none

mod

erat

e 2-

5 m

m

suba

ngul

ar b

lock

yve

ry f

ew (

<2%)

fine

(<2

mm

) sa

line

crys

tals

B3.2

to

.3 c

lear

to

light

cla

ygr

eyis

h br

own

(2.5

Y52�

co

mm

on (

10-2

0%�

med

ium

(5

-15

mm

� fa

int

brow

n m

ottl

esno

nem

oder

ate

2-5

mm

su

bang

ular

blo

cky

very

few

(<2

%) fi

ne (

<2 m

m)

salin

e cr

ysta

ls

C.3

to

.4 c

lear

to

light

cla

ylig

ht o

live

grey

(5

Y�2�

fe

w (

2-10

%) fi

ne (

<5 m

m)

fain

t br

own

mot

tles

none

mas

sive

none

2B.4

to

.5lig

ht m

ediu

m

clay

light

gre

y (5

Y72

� m

any

(20-

50%�

med

ium

(5-

15 m

m�

dist

inct

ora

nge

mot

tles

none

mas

sive

very

few

(<2

%) fi

ne (

<2 m

m)

man

gani

fero

us

soft

seg

rega

tion

s

Site

171

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

Ep

ical

care

ous,

Hyp

ersa

lic H

ydro

sol

Land

form

Ele

men

t Pl

aya

Mor

phol

ogic

al T

ype

Mid

slop

eH

oriz

onD

epth

(m

)Bo

unda

ryTe

xtur

eCo

lour

Mot

tles

Coar

se F

ragm

ents

Stru

ctur

eSe

greg

atio

nsA1

0 to

.01

sha

rp t

ofin

e sa

ndy

clay

lo

amve

ry d

ark

grey

(1

0YR

31�

none

none

-fe

w (

2-10

%) fi

ne (

<2 m

m)

salin

e cr

ysta

ls

B2.0

1 to

.05

dif

fuse

to

fine

sand

y cl

ay

loam

light

oliv

e br

own

(2.5

Y5��

m

any

(20-

50%)

fine

(<

5 m

m�

dist

inct

ora

nge

mot

tles

none

mas

sive

very

few

(<2

%) fi

ne (

<2 m

m)

calc

areo

us s

oft

segr

egat

ions

1D.0

5 to

.3

sha

rp t

ofin

e sa

ndy

light

m

ediu

m c

lay

light

bro

wni

sh

grey

(2.

5Y�2

� m

any

(20-

50%�

med

ium

(5

-15

mm

� fa

int

brow

n m

ottl

es

none

mas

sive

none

2D.3

to

.85

sha

rp t

ofin

e sa

ndy

med

ium

cla

ylig

ht b

row

nish

gr

ey (

2.5Y

�2�

none

none

mas

sive

none

3R.8

5 to

1-

-lig

ht r

eddi

sh

brow

n (2

.5YR

�3�

few

(2-

10%)

fine

(<5

mm

) di

stin

ct r

ed m

ottl

esve

ry a

bund

ant

(>90

%�

mud

ston

e m

ediu

m

pebb

les

(�-2

0 m

m�

-no

ne

Soil Indicators of Queensland WetlandsSi

te 1

72Cl

assi

fica

tion

Au

stra

lian

Soil

Clas

sifi

cati

on

Stra

tic

Rudo

sol

Land

form

Ele

men

t Pl

aya

Mor

phol

ogic

al T

ype

Upp

er s

lope

Hor

izon

Dep

th (

m)

Boun

dary

Text

ure

Colo

urM

ottl

esCo

arse

Fra

gmen

tsSt

ruct

ure

Segr

egat

ions

A10

to .

05 s

harp

to

light

san

dy c

lay

loam

oliv

e (5

Y54�

none

very

few

(<2

%� a

ngul

ar s

hell

smal

l peb

bles

(2-

� m

m�

-no

ne

1D.0

5 to

.1 s

harp

to

clay

ey s

and

oliv

e (5

Y53�

few

(2-

10%�

med

ium

(5

-15

mm

� fa

int

yello

w m

ottl

es

very

few

(<2

%� a

ngul

ar s

hell

smal

l peb

bles

(2-

� m

m�

-ve

ry f

ew (

<2%)

fine

(<2

mm

) ca

lcar

eous

sof

t se

greg

atio

ns

2D.1

to

.15

sha

rp t

osa

ndy

clay

pale

bro

wn

(10Y

R�3�

few

(2-

10%)

fine

(<

5 m

m�

fain

t br

own

mot

tles

very

few

(<2

%� a

ngul

ar s

hell

smal

l peb

bles

(2-

� m

m�

-ve

ry f

ew (

<2%)

fine

(<2

mm

) ca

lcar

eous

sof

t se

greg

atio

ns

3D.1

5 to

.4

sha

rp t

ocl

ayey

san

dol

ive

brow

n (2

.5Y4

4�no

neve

ry f

ew (

<2%�

ang

ular

she

ll sm

all p

ebbl

es (

2-�

mm

�-

very

few

(<2

%) fi

ne (

<2 m

m)

calc

areo

us s

oft

segr

egat

ions

4D.4

to

.9 s

harp

to

med

ium

cla

ylig

ht b

row

nish

gr

ey (

2.5Y

�3�

none

none

-no

ne

5D.9

to

1-

light

med

ium

cl

aylig

ht b

row

nish

gr

ey (

2.5Y

�2�

none

none

-co

mm

on (

10-2

0%)

fine

(<2

mm

) gy

pseo

us c

ryst

als

Soil

Chem

istr

y

Site

Dep

th (

m)

pH*

EC dS/m

Cl mg/

kgN

O3-

Nm

g/kg

TC**

%T

N**

%C

am

eq/1

00g

Mg

meq

/100

gN

am

eq/1

00g

K meq

/100

gES

P%

CEC

meq

/100

g

170

0.00

-0.1

07.

87.

08�2

307

1.29

0.1�

119.

5�10

.12.

7131

.�32

0.20

-0.3

07.

79.

1911

000

<10.

50.

052.

9�11

.114

.�2.

4�43

.134

0.40

-0.5

07.

89.

�12

000

230.

090.

043.

3�13

.41�

.73.

314�

.43�

171

0.00

-0.1

07.

813

1�40

022

0.21

0.04

2.�8

10.2

�.44

1.82

2�.8

24

0.20

-0.3

08.

28.

3910

100

150.

120.

041.

9412

.�12

.32.

�443

.928

0.40

-0.5

08.

35.

�57

4010

0.1

0.03

2.2

11.7

13.5

2.55

41.3

33

172

0.00

-0.1

08.

51.

4591

�5

0.1

<0.0

34.

041.

240.

450.

35�.

47

0.20

-0.3

09.

21.

3215

20<1

0.07

<0.0

31.

481.

051.

2�0.

2829

.34

0.40

-0.5

08

10.2

1320

01

0.11

<0.0

33.

229.

0513

.12.

3552

.725

*Aqu

eous

1:5

**

Tota

l car

bon

and

tota

l nit

roge

n

Refe

renc

es1.

Que

ensl

and

Dep

artm

ent

of N

atur

al R

esou

rces

and

Wat

er (

2008

). S

ILO

[on

line]

. Av

aila

ble

at h

ttp:

//w

ww

.lon

gpad

dock

.qld

.gov

.au/

silo

/ [a

cces

sed

5/11

/200

7].

2. I

sbel

l RF

(20

02).

The

Aus

tral

ian

Soil

Clas

sifi

cati

on.

CSIR

O P

ublis

hing

, Co

lling

woo

d, V

icto

ria,

rev

ised

edi

tion

.

3. E

PA (

2008

) Re

gion

al E

cosy

stem

s. [

onlin

e].

Avai

labl

e at

htt

p://

ww

w.e

pa.q

ld.g

ov.a

u/na

ture

_con

serv

atio

n/bi

odiv

ersi

ty/r

egio

nal_

ecos

yste

ms/

[ac

cess

ed 2

8/06

/08]

.

4. B

urea

u of

Min

eral

Res

ourc

es (1

971)

. Eu

lo:

Aus

tral

ia 1

:250

,000

Geo

logi

cal

Seri

es,

Bure

au o

f M

iner

al R

esou

rces

, Ca

nber

ra.

5. B

ryan

t KB

, W

ilson

PR,

Big

gs A

JW,

Brou

gh D

M a

nd B

urge

ss J

W (

2008

). S

oil

Indi

cato

rs o

f Q

ueen

slan

d W

etla

nds:

Sta

te-w

ide

asse

ssm

ent

and

met

hodo

logy

. Q

ueen

slan

d D

epar

tmen

t of

Nat

ural

Res

ourc

es a

nd W

ater

. Br

isba

ne.

6. H

azel

ton

P an

d M

urph

y B

(200

7).

Inte

rpre

ting

Soi

l Te

st R

esul

ts:

Wha

t do

all

the

num

bers

mea

n?.

[2nd

ed]

. CS

IRO

pub

lishi

ng.

Colli

ngw

ood

Vict

oria

.

93

11

66

21

80

64

3