Soil

Ind

icat

ors

of Q

uee

nsla

nd W

etla

nds Carbrook Wetlands

Study Area Carbrook Conservation Park is located approximately 35 km south-east of Brisbane, South-East Queensland. The park covers 103 ha of Melaleuca quuinquinervia (Paper Bark Teatree), Casuarina glauca (Swamp Oak) and mixed Eucalypt forest which runs along tidally influenced Native Dog Creek1.

This study area is a typical example of a coastal and sub-coastal floodplain tree swamp (melaleuca and euclyptus spp.) in the South-East Queensland Bioregion.

Climate2

0

100

200

300

400

500

600

700

800

900

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

Rain

fall-

Evap

orat

ion

(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 subtropical climatic region with a wet and dry season. Evaporation exceeds rainfall in the majority of months. The average annual rainfall for the area is 1257 mm.

Landform and Inundation

Swamp next to creek and river floodplainsFreshwater seasonal inundation from overland flow Some tidal influence on extremely high tides

Soils3 Hydrosols

Vegetation4 Melaleuca quinquenervia open forest on coastal alluvium (RE 12.3.5)

Geology5 Estuarine, floodplain and tidal delta deposits

Disturbance No effective disturbance

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Location GDA94 • MGA Coordinates : 526726 E, 6937382 N, Zone 56 • Lat/Long : -27.68752 S, 153.27104 E

Landscape Diagram

Saturated zone

Native Dog creek

Phragmites australis

Transition zone

Melaleuca quinquenervia community

Site 215Site 217

Levee

Water table

0.2m

Site 216

100 m

Soil ProfilesSite 217Site 216Site 215

0.1 mP1

0.2 m

0.45 m

0.8 m

A1

B2

P2

0.1 mA11

0.3 m

0.45 m

0.7 m

0.9 m

A12

A3

B1

1.0 m

B21

B22

0.1 mP1

0.3 m

0.5 m

1.0 m

0.8 m

P2

A1

B21

B22

Organic materials,

high organic carbon content,

dark soil colours, high water table

and presence of sulfidic

materials are all positive

indicators of a saturated or reduced

environment

Organic materials, high organic carbon content, dark soil colours, high water table and

ferruginous root channel linings are all indicators of a saturated or reduced

environment

Brighter sub-surface colours reflect elevated

drainage and comparatively less inundation

Organic materials, high organic carbon content, dark soil colours, high water table and

mottling are all indicators of a saturated

or reduced environment

Soil

In

dic

ator

s of

Q

ue

ensl

and

W

etla

nd

s Soil Indicators Present (within 0.3 m of surface)

Indicator6 Site 215 Site 216 Site 217 Organic materials and organic carbon (OC)*

Organic materials to 0.3 m OC%: 28.2

Organic materials to 0.1 m OC%: 16.3

Organic materials to 0.3 mOC%: 19.2

Matrix colour Dark brown to black Black Black

Chroma (thickness of layer)**

Present (0.2 m) Present (0.3 m) Present (0.3 m)

Mottles and Segregations

Not present Not present Few <5 mm distinct dark mottles

Depth to groundwater 0.02 m 0.2 m 0.05 m

Ferruginous root channel and pore linings

Not present Present Not present

pH*7 Very strongly acid Very strongly acid Very strongly acid

Texture Loam to light clay Loam to light clay Loam

Acid sulfate material Present Not present Not present

Electrical Conductivity (EC)7

Moderately saline Non saline Moderately saline

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

Summary of Field ObservationsPresence of swamp hummock microrelief denotes a saturated environment

Dark soil surface colours and greyish colours at depth are positive indicators of saturated conditions

High organic carbon levels and organic material within the surface 0.3 m indicate saturated conditions at all sites

Thickness of the organic material layer in the surface 0.3 m at site 216 is smaller than at the other sites, this is due to the site being located higher in the landscape (on a levee) and therefore not inundated as long as the other sites

Poor external drainage predisposes the area to saturated conditions

Hydrogen sulfide gas detected in the saturated zone and presence of iron staining of the surrounding environment indicates a reduced environment and the presence of sulfidic materials.

Faint and distinct mottling signifies water fluctuation throughout all profiles

References1. QPWS (1999) Carbrook Wetlands Conservation Park: Management Plan. Queensland Parks and Wildlife Service. Brisbane

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 (1978). Moreton: 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

•

•

•

•

•

•

•

Soil Indicators of Queensland WetlandsSo

il M

orph

olog

y

Site

215

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

Su

lfur

ic E

xtra

tida

l Hyd

roso

lLa

ndfo

rm E

lem

ent

Swam

pM

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

P10

to .1

-fib

ric

loam

brow

nish

bla

ck

(10Y

R32)

no

neno

nem

oder

ate

angu

lar

bloc

kyno

neve

ry w

eak

wet

P2.1

to

.2-

sapr

ic lo

amda

rk b

row

n (1

0YR3

3)

none

none

mod

erat

e an

gula

r bl

ocky

none

very

wea

k w

et

A1.2

to

.45

-sa

pric

ligh

t cl

aybl

ack

(5Y2

1)

none

none

mod

erat

e an

gula

r bl

ocky

none

wea

k w

et

B2.4

5 to

.8

-m

ediu

m

clay

brow

nish

bla

ck

(2.5

Y31)

ve

ry f

ew (

<2%)

fin

e (<

5 m

m)

fain

t ye

llow

mot

tles

none

mas

sive

none

firm

wet

Site

216

Clas

sifi

cati

on

Aust

ralia

n So

il Cl

assi

fica

tion

Su

lfur

ic E

xtra

tida

l Hyd

roso

lLa

ndfo

rm E

lem

ent

Leve

eM

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

P20

to .1

cle

ar t

osa

pric

loam

blac

k (5

Y21)

no

neno

nem

oder

ate

gran

ular

very

few

(<2

%)

fine

(<2

mm

) fe

rrug

inou

s ro

ot

linin

gs

wea

k m

oist

A1.1

to

.3 g

radu

al t

olig

ht c

lay

blac

k (5

Y21)

no

neno

nem

oder

ate

suba

ngul

ar b

lock

yno

new

eak

moi

st

A3

.3 t

o .4

5 g

radu

al t

ohe

avy

light

cl

ayol

ive

blac

k (5

Y22)

few

(2-

10%)

fine

(<

5 m

m)

fain

t ye

llow

mot

tles

none

mod

erat

e su

bang

ular

blo

cky

none

firm

wet

B1.4

5 to

.7

gra

dual

to

light

m

ediu

m

clay

yello

wis

h gr

ey

(2.5

Y41)

co

mm

on (

10-2

0%)

med

ium

(5

-15

mm

) pr

omin

ent

yello

w

mot

tles

none

mas

sive

none

firm

wet

Soil Indicators of Queensland WetlandsSi

te 2

17Cl

assi

fica

tion

Au

stra

lian

Soil

Clas

sifi

cati

on

Sulfi

dic,

Ext

rati

dal H

ydro

sol

Land

form

Ele

men

t Sw

amp

Mor

phol

ogic

al T

ype

Flat

H

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

P10

to .1

-fib

ric

loam

blac

k (5

Y21)

fe

w (

2-10

%) fi

ne

(<5

mm

) di

stin

ct

dark

mot

tles

none

-no

neve

ry w

eak

moi

st

P2.1

to

.3-

sapr

ic

loam

blac

k (2

.5Y2

1)

none

none

mod

erat

e su

bang

ular

blo

cky

none

wea

k w

et

A1.3

to

.5-

light

m

ediu

m

clay

brow

nish

bla

ck

(2.5

Y31)

very

few

(<2

%)

fine

(<5

mm

) fa

int

brow

n m

ottl

es

none

mas

sive

none

firm

wet

B21

.5 t

o .8

-m

ediu

m

clay

grey

(2.

5Y51

) fe

w (

2-10

%)

med

ium

(5

-15

mm

) pr

omin

ent

yello

w

mot

tles

, ve

ry f

ew

(<2%

) m

ediu

m

(5-1

5 m

m)

dist

inct

bro

wn

mot

tles

none

mas

sive

none

firm

wet

B22

.8 t

o 1

-m

ediu

m

clay

grey

(5Y

41)

very

few

(<2

%)

med

ium

(5

-15m

m)

dist

inct

br

own

mot

tles

none

mas

sive

none

firm

wet

Soil

Chem

istr

y

Site

Dep

th (

m)

pH*

EC (

dS/m

)Cl

(m

g/kg

)N

O3-

N (

mg/

kg)

TC%

**TN

%**

215

0.00

-0.1

05

1.56

4100

<128

.21.

23

0.20

-0.3

05.

64.

0860

80<1

7.22

0.37

0.40

-0.5

06.

44.

9471

00<1

3.15

0.17

216

0.00

-0.1

04.

80.

4154

0<1

16.3

0.88

0.20

-0.3

04.

50.

5362

7<1

5.31

0.34

0.40

-0.5

04.

30.

9312

40<1

3.05

0.18

217

0.00

-0.1

04.

42.

0745

40<1

19.2

0.89

0.20

-0.3

04.

12.

1328

50<1

4.01

0.25

0.40

-0.5

04.

12.

0628

50<1

1.67

0.11

*Aqu

eous

1:5

**To

tal c

arbo

n an

d to

tal n

itro

gen

93

11

66

21

80

64

3