9373.48 KB - South West NRM

STUDIES
ON THE VEGETATION
OF
SOUTH-WESTERN QUEENSLAND
by
Desmond Ernest Boyland (B.Sc.
A t h e s i s submitted i n fulfilment of t h e requirements f o r
t h e degree of
Master of Science
Department of Botany
University of Queensland
December, 1981
STATEMENT OF AUTHENTICITY
I c e r t i f y t h a t unless otherwise s t a t e d t h e
contents of t h i s t h e s i s a r e o r i g i n a l .
The
t h e s i s has not been submitted f o r any other
degree.
w3
D.E.
Boyland
P l a t e 1.
Water hole on Cooper Creek, Nappa Merrie with
fring+ng EucaZyptus rnicrotheca open woodland
( F l o r i s t i c association 3 ) .
ABSTRACT
The thesis comprises two sections.
The first section provides
nsive account of the vegetation of a 15 million hectare region
th-western Queensland.
The second section presents a collection of
hed papers and reports relevant to the region.
A
review of the region and its physical attributes is given.
It
n the 400 nun to 100 nun rainfall zone and experiences an arid climate.
aphy of the area slopes to the west and the south.
A
series of four
r less parallel ranges separate the various drainage catchments.
e is the "channel" country in the west.
A
The region forms part of
omanga Basin vhich is a sub basin of the Great Artesian Basin.
The
ical sequence of the Eromanga Basin is based on a conformable
sion of Jurassic, Cretaceous and Tertiary sediments all of which were
weathered in the Tertiary period.
a1 sediments in many areas.
Quaternary deposits overlay the
Landscape development reflects the
ying geology and geological situation.
are delineated.
Seven major physiographic
Soils can be grouped into eight major soil groups.
racking clays are the most productive but the red earths and associated
are the most extensive.
The flora of the region is poor.
ich 730 are angiosperms.
sperms.
A
Only 737 species were recorded
Dicotyledons (568 spp.) predominate the
list of all species recorded is given together with their
habitat preference.
Families with large numbers of different
es include Poaceae, Leguminosae (in the traditional sense),
podiaceae and Asteraceae to which in total 49% of all species belong.
genera present are Acacia, EremophiZa, Eragrostis, ScZeroZaena and
da.
Only five species are endemics and the region supports twelve
species now naturalized.
Comparisons with similar regions within
alia are carried out using the Index of Similarity developed by
nsen and the Coefficient of Similarity developed by Preston.
The
a exhibits most affinity to that of an area located to its immediate
h and least with the flora of the Simpson Desert.
The area is of
togeographic interest with major disjunctions of vegetation types
egion.
An examination of t h e genera supports
mposition of t h e present f l o r a i s of r e c e n t o r i g i n
sted t h a t the f l o r a comprises four elements, remnants of a
t f l o r a , genera t h a t reinvaded from adjacent regions t o which
d during c l i m a t i c v a r i a t i o n s , genera t h a t invaded t o occupy
acant niches and genera t h a t have evolved i n t h e area.
t h e genus
The
Acacia within t h e region i s examined and t h e
support the general hypothesis t h a t the f l o r a comprises four
Vegetation i s characterized by s t r u c t u r a l l y simple associations
e i g h t and p r o j e c t i v e f o l i a g e cover.
s t i n c t layering.
.
These associations usually
Twenty one s t r u c t u r a l formations were
S t r u c t u r a l formations favour p a r t i c u l a r s o i l groups.
e n t of these formations i s a l l i e d t o moisture a v a i l a b i l i t y .
The
The
on has been divided i n t o t e n major groupings based l a r g e l y on
c s o r i n some s i t u a t i o n s predominant life-form.
These groupings
divided on s t r u c t u r a l formation and f u r t h e r subdivided on f l o r i s t i c s
basic u n i t of d e s c r i p t i o n the f l o r i s t i c association.
s t i c associations i s erected.
A t o t a l of
These are described i n terms of
a1 formation range, t h e height, p r o j e c t i v e f o l i a g e cover and d e n s i t y
arious component s t r a t a and t h e frequently occurring species.
s on preferred h a b i t a t s and s o i l types a r e given.
Two vegetation maps, a t a s c a l e of 1:l 000 000, r e l e v a n t t o t h e
There i s an obvious d i f f e r e n c e i n the l e v e l of
a r e presented.
on and d e t a i l between t h e two maps.
The Major Vegetation Group map
t e s 10 d i s t i n c t mapping u n i t s whereas i n the more c o s t l y SouthQueensland, Vegetation of Queensland s e r i e s map 23 d i s t i n c t mapping
ad been erected.
Section I1 comprises four papers and seven chapters o r appendices
ious r e p o r t s .
These publications i l l u s t r a t e some p r a c t i c a l
a t i o n s of d a t a collected and add f u r t h e r t o t h e knowledge of t h e
ion of t h e region of south-western Queensland.
.
.
vegetation. Western Arid Region Land
U s e Study
P a r t I1
-
Land Systems. Western Arid Region Land
Use Study - P a r t I
Land Units. Western Arid Region Land
Part I
Use Study
.
.
.
.
.
.
-
Land Systems. Western Arid Region Land
Use Study
P a r t I1
-
Land Units. Western Arid Region Land
P a r t 11
Use Study
-
Resource Use. Western Arid Region Land
Part I
Use Study
-
Land Management i n South West Queensland
Resource Use. Western Arid Region Land
Use Study
P a r t 11
-
Comparison of t h r e e small-scale
vegetation mapping techniques
CONCLUSIONS
REFERENCES
(1:l 000 0 0 0 )
188
LIST UF
-
3.1
FIGURES
Average annual isohyets and histograms of
29
monthly r a i n f a l l from J u l y t o June a t
selected l o c a l i t i e s .
3.2
Mean monthly maximum and minimum temperatures
a t Thargomindah and Eulo.
30
Estimated average
d a i l y t o t a l r a d i a t i o n f o r each month general
t o t h e whole area.
3.3
~ o p o g r a p h i cmap.
32
3.4
~ i s t r i b u t i o nof physiographic u n i t s .
34
5.1
Locality map f o r regions compared.
61
5.2
The proposed sequence of t h e development of
71
t h e major groups of Acacia.
EucaZyptus ochrophloia open woodland, flood
80
p l a i n of t h e Paroo River near Eulo.
EucaZyptus microtheca grassy low open woodland,
floodplain
80
of t h e Wilson River west of
Thargomindah.
Acacia cambagei low open woodland, a l l u v i a l p l a i n
82
adjacent t o Bulloo River, near Quilpie.
Acacia cambagei t a l l open shrubland, extend&
flank of mantled pediment, west of Eromanga.
Acacia aneura, EucaZyptus popuznea grassy low open
84
woodland, run-on s i t u a t i o n on p l a i n s of low r e l i e f ,
Humeburn
.
Acacia aneura t a l l open shrubland, sand p l a i n e a s t
84
of Thargomindah.
AtaZaya hemiglauca, Acacia aneura low open woodland,
eroded dunes adjacent t o t h e floodplain
86
of t h e
Bulloo River, Bulloo Downs.
Acacia catcicoZa t a l l open shrubland, low dunes
86
south of Naryilco.
Acacia aneura t a l l open shrubland, Nerrigundah,
^
88
south-west of Quilpie.
Acacia stowardii low open shrubland, Grey Range
88
west of Quilpie.
AtripZex n m u l a r i a low open shrubland, edge of
90
floodplaizl of Bulloo River, Bulloo Downs.
Muehtenbeckia cunninghamii low open shrubland,
floodplain of t h e Cooper Creek.
90
adoxa open hummock grassland,
mobile c r e s t of l o n g i t u d i n a l dunes, Arrabury.
Triodia basedowii open hunuwck grassland,
extended dune f l a n k s with a s a l t l a k e i n t h e
background, Orientos.
AstrebZa pectitvzta open tussock grassland, stony
downs,Mt. Howitt
-
94
t h e r e s u l t of above average
seasonal r a i n s .
Sparse herbland, stony downs,
Mt.
Howitt
-
the
r e s u l t of below average seasonal r a i n s .
Open forbland, floodplain of Cooper Creek.
Sparse forblands with A r t h r o c n e m spp. low open
shrubland i n t h e background, Lake Bindegolly
e a s t of Thargomindah.
The Major Vegetation Groups.
Land Use Study
-
Western Arid Region
Pocket
Part I
South-western meensland.
1:l 000 000 Vegetation
p a r t 11
Western Arid Region Land Use Study
Rear
Pocket
survey of Queensland mapping s e r i e s
Vegetation.
Rear
-
Rear
Pocket
LIST OF TABLES
Suggested sera1 p a t t e r n s i n western Queensland.
Numerical dominants of t h e $round f l o r a f o r
t h e various groups.
Average monthly and seasonal r a i n f a l l (mm).
A t t r i b u t e s and c l a s s ranges used.
S t r u c t u r a l formations recorded i n the study
Proposed shrubland c l a s s i f i c a t i o n .
Number of f a m i l i e s , genera and species
recorded.
Families represented by 7 o r more species.
Genera represented by 7 o r more species.
Coefficients and indices of s i m i l a r i t y f o r
t h e various regions.
Regrouping of biophysical regions based on
vegetation.
Number of genera from t h e geographic elements
recognized.
Species, groups, geographic region a f f i n i t i e s
and h a b i t a t r e l a t i o n s h i p s .
Distribution of major s t r u c t u r a l formations on
-
major s o i l type groupings.
Major vegetation group and f l o r i s t i c associations
delineated i n the common area.
Number of i n t e r c e p t s of t r a n s e c t l i n e s with
f l o r i s t i c associations o r major group
boundaries and number of d i f f e r e n t map u n i t s
traversed.
SECTION
I
r i e d out t h e f i r s t d e t a i l e d study of vege
e s c r i b e a l l the important p l a n t communities i n
t e r n Queensland.
This region was bounded i n t h e
isohyet and included t h e study area.
Blake outlined
s of various communities giving limited species
d a t a and discussed b r i e f l y the s t a t u s of t h e communities and
ionship.
Limited q u a n t i t a t i v e d a t a on heights of some
ons were given but generally no q u a n t i t a t i v e d a t a on a t t r i b u t e s
l e s composition were supplied.
On a s t r u c t u r a l , f l o r i s t i c o r
b a s i s Blake c l a s s i f i e d t h e vegetation i n t o broad groups which
divided on a f l o r i s t i c b a s i s .
The outcome f o r t h e study area
TIES OF SANDHILLS.
5. Some claypans.
TEE SHRUB STEPPE FORMATION.
((1%)
DESERT FORMATION.
1. Simpson sand d e s e r t
(6%)
2. S t u r t stony d e s e r t
(41%)
Blake s t a t e ? t h a t the major f a c t o r s influencing the vegetation
a r t o be s o i l types, incidence of r a i n and drainage.
He commented
e f l u c t u a t i o n climax between chenopod predominant communities and
t c h e l l g r a s s a s s o c i a t i o n s , t h e apparent tendency f o r gidyea t o invade
avelly downs and t h e reverse s i t u a t i o n wher
i a lands.
He drew t h e conclusion t h a t , s i m i l
ueensland, t h e vegetation i s of an unstable nature.
udied t h e general ecological c h a r a c t e r i s t i c s of
e Australian plague l o c u s t (Chortoicetes term-inifera
he minor outbreak a r e a s was near Quilpie within the
d account of t h e vegetation was given which yielded
l o r i s t i c s o r p l a n t associations and their r e l a t i o n s h i p s .
It of i n v e s t i g a t i o n s undertaken i n the channel
(1947a) contributed t o t h e e x i s t i n g knowledge of t h e
e channel country within t h e study area.
He c l a s s i f i e d
n t o two broad categories based on topography, t h e r e l i e f
e flooded country.
) and s p i n i f e x
The r e l i e f country c o n s i s t s of mulga
(T'riodia basedowii) sand-ridges with i n t e r -
ans, downs country variously covered w i t h gibbers,ranges of
sandhills.
The flooded country c o n s i s t s of t h e Cooper flood-
e floodplains of t h e l o c a l creeks and anyone may merge w i t h
i n years of high flood.
Skerman followed t h e formations and
s a s defined by Blake (1938) b u t added valuable d a t a on the
omposition of t h e v ~ i o u seissociations.
He discussed t h e
arious types of floods, t h e seasons of flooding and the
of flooding on species composition.
Local summer floods
e g e t a t i o n composed mainly of Panicwn whitei, IseiZema spp.,
teniton radulans, Brachyachne convergens and ChZoris spp. with
Zva and LeptochZoa digitata occurring i n the wetter s i t u a t i o n s .
ed herbage includes AtripZex mueZZeri, SaZsoZa kaZi, Bassia spp.
oZaena spp.) and Amaranthus mitcheZZii.
General summer floods
e s u l t i n extensive stands of EchinochZoa t m e r a n a whereas
looding y i e l d s pastures of T'rigoneZZa suavissima, Craspedia spp.
e r members of Compositae ( = Asteraceae).
The d i s t r i b u t i o n of the
e c i e s i s determined by a number of f a c t o r s chief of which i s the
of wetting.
The arboreal vegetation i s made up of associations
Zyptus camaZduZensis, E. microtheca with occasional patches of
uca Zineariifotia f= M. trichostachya I . Limited areas of
t u s ochrophZoia occur.
Acacia cambagei and A. cyperophyZZa
i t i e s a r e associated with l o c a l watercourses.
Depressions and
ay support shrublands of MuehZenbeckia cunninghmnii an&
d i m auricomwn.
The vegetation of t h e r e l i e f country ranges from
ns with A.
c d a g e i communities on the low
d i s s e c t e d r e s i d u a l s and t h e scarp r e t r e a t zones supportin
A. petraea) communities.
Triodia base
ed with the dunefields and sand-plains.
The
vegetation consisting of AstrebZa pectinata,
AtripZex spongiosa and Bassia spp.
(=
ScZeroZaena
The composition and abundance of species depends on l o c a l r a i n s .
t i t a t i v e d a t a were given.
The d i s t r i b u t i o n of Acacia aneura i n Queensland together with
limate, topography and s o i l s of areas supporting A. aneura were
ssed by E v e r i s t (1949).
e t i e s of A.
According t o E v e r i s t t h e r e a r e many
aneura which can be distinguished i n both the herbarium
f i e l d but t h e r e a r e two extreme v a r i e t i e s i n Queensland, the
eaved v a r i e t y i n the e a s t of the range and t h e narrow-leaved
i n t h e w e s t and towards t h e northern limits.
The various growth
d by grazing, whip-stick mulga immature t r e e s not modified by
dy loams of south-western Queensland.
I n Queensland, A. afleura
a i n l y between the 8-inch (200 mm) and 20-inch
.
(500 mm) annual
Within t h e A. aneura f o r e s t s and scrubs many species of grasses
age p l a n t s a r e found.
Other t r e e s and shrubs a l s o form p a r t of
EwtaZyptus popuZnea i s conspicuous i n t h e e a s t with
hZoia f l o u r i s h i n g on f i n e sands and E. terminalis more conspicuous
community.
est.
A l i s t of species collected during h i s s t u d i e s was compiled
g 257 spp. i n a l l .
An examination of t h i s l i s t shows t h a t only
a r e perennial woody species y e t t h e woody component of the
e s i s by f a r t h e dominant l i f e form.
Large families included
e , Leguminosae, Malvaceae, Compositae, Chenopodiaceae and
Some comments were given on the e f f e c t s of thinning A. aneura
rence of s o i l erosion i n lands supporting A. aneurrz.
s t of the d a t a were collected e a s t of the study area.the
have a d i r e c t relevence t o the A. aneura communities of the
A b r i e f overview of the Mitchell grass country of Queensland
ented by E v e r i s t (1964).
The climate, topography, s b i l s ,
a t i o n and productivity of the lands supporting mainly AstrebZa spp
e discussed.
The climate of t h e country i s semi-arid with the g r e a t
lk of i t l y i n g between t h e 500 mm and 250 mm isohyets.
e l i a b l e and v a r i a b l e .
Rainfall i s
S o i l s a r e mainly dark grey cracking clays.
trebZa spp. a r e tussocky perennial grasses with a b a s a l cover of
l l y l e s s than 4%.
E v e r i s t divided t h e p l a n t s which a r e associated
these grasses i n t o two broad c l a s s e s , drought r e s i s t e r s and drought
odgers.
The l a t t e r can be f u r t h e r divided i n t o perennials which can
rvive by means of storage roots o r rhizomes and annuals which grow
i d l y w h i l s t conditions a r e good producing seeds which l i e dormant
n t i l t h e next favourable season.
L i t t l e d e t a i l e d d a t a were given:.on
e floristics.
Burrows and Beale (1969) c a r r i e d out a d e t a i l e d botanical survey
woody species i n two Acacia aneura areas t o i n v e s t i g a t e t h e s t r u c t u r e
d p a t t e r n s exhibited by the various p l a n t associations.
The i n t e r p r e t -
t i o n of t h e i r d a t a r e s u l t e d i n a b e t t e r understanding of woody species
omposition of the various p l a n t associations and t h e r e l a t i o n s h i p between
e s i t e groups recognized.
Results from t h e Humeburn site and t o a
s s e r degree t h e Tobermor,y s i t e , suggested a gradation i n t h e s i t e
roups from depressions t o t h e top of scarps.
The depressions support
ucaZyptus populnea, Eremophila mitcheZZii associations with Acacia aneura
ommunities associated with ridges and t h e edges of scarps and tops of
carps supporting Acacia kempeana ( a c t u a l l y A. s t m a r d i i ) associations.
ncreasing elevation from f l a t s t o tops of scarps and perhaps decreasing
o i l depth seemed t o be t h e main f a c t o r s c o n s i s t a n t w i t h community changes.
t was a l s o indicated t h a t microtopography was an important determinant
f species d i s t r i b u t i o n i n the s i t e s studied.
Analysis suggested strong
vidence of contagion within these semi-arid woodland species which
n t r a s t s with random d i s t r i b u t i o n noted f o r many Australian dry larid
ants.
Evidence of random p l a n t d i s t r i b u t i o n was found by the authors
y f o r EucaZyptus populnea..
Burrows and Beale a l s o suggested t h a t
onsideration of species density d a t a as well a s frequency i s necessary
c l a s s i f y i n g communities i n t h i s area.
It was considered t h a t t h e
fluence of s o i l pH and other edaphic f a c t o r s on d i s t r i b u t i o n p a t t e r n s
4
species deserved f u r t h e r a t t e n t i o n .
Clark e t aZ. (1969), who were primarily i n t e r e s t e d i n l o c u s t
Ontrol i n south western Queensland and north western New South Wales,
escribed t h e f l o r i s t i c s of some p l a n t associations i n t h e study area.
t h e region on t h e land form c l a s s i f i c a t i o n of
i n t o areas presenting d i s t i n c t i v e h a b i t a t s .
These
were s t o n y h i l l s and r i d g e s , stony downs, d e s e r t l o w , sand
dune complex, channel flood p l a i n s , creek flood f l a t s and high
plains.
Each h a b i t a t type was described and t h e vegetation,
erms, was r e l a t e d t o s o i l groupings.
L i t t l e new d a t a were
o t h e e x i s t i n g knowledge of t h e vegetation.
Clark e t
aZ.
zed t h e importance of r a i n f a l l and i t s r e d i s t r i b u t i o n on t h e
fluence of microtopography on species d i s t r i b u t i o n .
a n t i t a t i v e d a t a were given.
Boyland (1973) discussed t h e vegetation of lands where
Acacia
a predominates o r contributes s i g n i f i c a n t l y t o t h e biomass of t h e
tern with s p e c i a l reference t o south-western Queensland.
I t was
aneura forms s t r u c t u r a l l y simple associations low
g h t and v e g e t a l cover.
The physiognomic complexity of A. aneura
a t usually A.
a t i o n s decreases along a g r a d i e n t from a favourable environment
ox. 500 mm annual r a i n f a l l ) t o a harsh environment (approx. 200 mm
1 rainfall).
The a s s o c i a t i o n s o c c w mainly a s t a l l shrublands and
open shrublands.
They reach t h e i r b e s t expression on red e a r t h s on
t l y undulating t o f l a t p l a i n s derived from t h e d i s s e c t i o n of t h e
ary land surface.
F l o r i s t i c a l l y these areas a r e r e l a t i v e l y p,oor
e t a i l e d d a t a were given f o r south-western Queensland.
Gramineae,
nosae, Compositae, Chenopodiaceae and Myoporaceae c o n t r i b u t e
Acacia, Bassia I=
Zaenal, Cassia, EremophiZa, Aristida and Eragrostis.
Boyland
luded t h a t Acacia aneura lands a r e not a s i n g l e a s s o c i a t i o n b u t
ficantly t o the flora.
Large genera include
i s e many varied p l a n t associations.
Studies by Roberts (1972) were primarily concerned with t h e
nation of t h e condition of t h e n a t u r a l grazing lands of western
ensland and with t h e evaluation of t h e p o s s i b i l i t i e s of grazing land
agement i n this region.
Data c o l l e c t e d during t h e s t u d i e s contributed
t h e knowledge of t h e composition of t h e ground l a y e r of both
ura and AstrebZa spp. communities.
Acacia
Roberts discussed p a t t e r n s and
t u l a t e d s u c c e s s i o ~ a lp a t t e r n s i n ground f l o r a communities.
gested p a t t e r n s a r e given i n Table 2.1.
These
f o r t h e various major s o i l
Pioneer spp.
Climax spp.
Digi t a r i a m o p h i Za
mitcheZliana
Themeda austraZis
Cymbopogon obtectus
(post climax)
Themeda avenacea
avenaceus
Themeda austraZis
Triodia basedowii
Triodia marginuta
Perotis r a m
Triraphis moZZis
Amphipogon earicinus
Eriachne mueronata
Monachatker paradoxa
SoZanwn elZipticwn
(=SeZeroZaena spp.)
cont
.
EvoZvulus alsinoides
Momchather paradoxa
Triodia basedowii
Amphipogon caricinus
PortuZaea sp. af f .
EremophiZa bowmanii
EremophiZa Zatrobei
!Thyridolepis mitcheZZiam
Aristida ZatifoZia
AstrebZa Zappacea
Brachyachne convergens
DactyZocteniwn raduZans
Dichanthiwn sericewn
Eragrostis setifoZia
AbutiZon maZvifoZiwn
AtripZex meZZeri
Bassia spp. (=ScZeroZaena spp.
Boerhavia d i f f u s a
Hibiscus trionwn
MaZvastmvn americanwn
Minuria integerrima
PhytZanthus maderaspatensis
Potymeria marginata
PortuZaca spp.
Rhynchosia minima
SaZsoZa kaZi
SoZanwn esuriaZe
Trimthema triquetra
These s t.u d i. e.s by Roberts h i g h l i g h t s the important contribution
a such a s Aristida, Eragrostis, AstrebZa, Monachather, Th@idoZepis,
Lon, Sida and Bassia I= ScZeroZaeml make t o t h e f l o r a of t h e region.
mportance of moistwe and i t s over-ruling e f f e c t on vegetation of
egion was emphasized.
The r e s u l t s of t h e f i e l d s t u d i e s sh6wed t h a t
and t h e numerical dominants are s i m i l a r on s i m i l a r s o i l s .
cover which may be expected t o develop.
Results
Some of t h e s i t e s studied
p o s ~ t l o n e doutside t h e study area b u t overal
r e c t relevence t o i t s vegetation.
) reviewed t h e e x i s i t i n g knowledge of
ia.
AstrebZa spp.
The review b r i e f l y examined what l i t t l e d a t a
n f l o r i s t i c s and s t r u c t u r e generally.
Astrebta Zappacea
t a a r e widely d i s t r i b u t e d t h e former dominant with
i n more e a s t e r l y a r e a s and t h e l a t t e r o f t e n with A.
e s t e r n edge.
. depends
Zappacea
I t was s t a t e d t h a t l o c a l d i s t r i b u t i o n of
on s o i l moisture.
A. ezymoides occurs on runon
s A. sqtcarrosa w h i l s t A. Zappacea tends t o favour well drained
e l o c a l d i s t r i b u t i o n of A.
pectinata i s not c l e a r .
A. Zappacea
nata are k i l l e d by flooding unlike t h e more t o l e r a n t A. eZym0ides
rosa.
Because of t h e wide l a t i t u d i n a l spread of Mitchell
sslands and t h e incidence of summer and winter r a i n t h e r e can be
a 1 d i f f e r e n c e s i n the minor components a t any p a r t i c u l a r s i t e .
i n produces a wide v a r i e t y of both annual and perennial grasses
DactyZocteniwn raduZans, IseiZema spp., SporoboZus
erhavia d i f f u s a and Bassia spp. (= ScZeroZaena spp.).
Regions
grasses such a s
' g n i f i c a n t winter r a i n f a l l e x h i b i t pastures which usually contain
proportion of non-grass species.
O r r s t r e s s e d t h a t t h e composition
bZa spp. associations w a s influenced not only by seasonal conditions
a s t grazing h i s t o r y .
Various workers, including Wood (1949), Williams (19551, Wood and
s (19601, Moore and Perry (1969), Specht (1970) and Carnahan (1976),
i n g w i t h t h e vegetation of Australia covered t h e study area.
Because
road nature of t h e various accounts no new d a t a on f l o r i s t i c
t i o n o r r e l a t i o n s h i p s of t h e various p l a n t associations were added.
s contribution is notable because of t h e introduction of a new
c a t i o n of s t r u c t u r a l formations which has gained wide acceptance
h w i t h some minor modifications by some workers.
This c l a s s i f i c a t i o n
so eliminated most of t h e confusion i n nomenclature used f o r various
u r a l categories.
According t o the map accompanying Specht's t e x t ,
udy area was mapped a s low woodland and t a l l shrubland i n +?he e a s t
imately 55% of the a r e a ) , d e s e r t complex i n t h e north west
imately 1 0 % ) ' tussock grassland i n t h e c e n t r a l w e s t (approximately
d low shrubland i n t h e c e n t r a l southern region (<5%).
Complexes
r t complex/tall open shrubland and low shrubland/tussook grassland
ndicated i n the west of the area.
26.
c a r r i e d out studies on t h e vegetation
ea b u t these s t u d i e s have been orientated towards productivity
Lon
t o t h e pastoral industry.
These studies contribute very
t h e knowledge of the f l o r i s t i c 5 of the area and t h e s t r u c t u r e
- THF
.. .- STllnY
- .-- .
3- .
ART2 HISTORY
.ARFA
.. .-..
a i n l y e a s t of Quilpie and Thargomindah sub-division
e r settlement were a f e a t u r e of t h e region u n t i l t h e
01p r i c e s , poor seasons and increased i n t e r e s t
d t h i s trend and amalgamations i n t o more economic
curring.
A more d e t a i l e d account of settlement and
e region i s given by Allen (1968).
The p a s t o r a l industry i s t h e major e n t e r p r i s e i n t h e area
et aZ.,1974).
and sheep.
Pastoral a c t i v i t y i s confined t o t h e grazing of
Beef production comprises both breeding and f a t t e n i n g
urs mainly i n t h e west of t h e area.
The sheep industry i s mainly
n wool production with t h e g r e a t e s t proportion of replacement
s bred within the area.
Sheep a r e confined t o t h e e a s t of t h e
but t h e r e i s a tendency f o r many e a s t e r n p r o p e r t i e s t o run some
Generally i n t h e e a s t t h e r e a r e s u f f i c i e n t watering places i n
on t o carrying capacity of t h e p a s t u r e t h a t sheep may use p r a c t i c a l l y
e area except f o r the dissected country where access i s l i m i t i n g .
west the area remained v i r t u a l l y i n an unimproved s t a t e f o r many
Graziers used t h e country on an open range b a s i s with access t o
1 watering holes determining stock numbers.
t u a t i o n has changed.
Over t h e l a s t 40 years
As a r e s u l t of improved technology and
t i s e , b e t t e r stock water f a c i l i t i e s are a v a i l a b l e and country s u i t a b l e
0th water storaqe and qrazinq now has been opened t o stock.
The climate of t h e a r e a i s a r i d , meaning t h a t t h e low r a i n f a l l
igh evaporation r e s u l t s i n inadequate s o i l moisture f o r crop
c t i o n (Winkworth and Thomas, 1974).
The low r a i n f a l l i s u n r e l i a b l e and frequently inadequate f o r
t growth.
, the
Even when s u f f i c i e n t r a i n f a l l i s received f o r p l a n t
high r a d i a t i o n and low humidity causes rapid evaporation from
o i l r e s u l t i n g i n dry s o i l s and p l a n t growth stops.
As a r & s u l t , t h e
a t i o n is characrerized by d i s t i n c t e r r a t i c and r e l a t i v e l y s h o r t
th periods followed by long periods of i n a c t i v i t y .
Winkworth and Thomas (1974) have discussed f u l l y t h e climate of
area and t h i s account i s based on t h e i r report.
31.
Humidity is low throughout the year.
Since the temperature of
ew p o i n t is lower i n dry a i r , t h e very low r e l a t i v e humidity values
ound i n this a r e a imply t h a t minimum night temperature w i l l r a r e l y be
ss than dew p o i n t .
Thus dew i s a negligible source of f r e e water.
Evaporation d a t a covers l e s s than 5 years and i s too s h o r t t o
s t a b l i s h r e l i a b l e averages.
Winkworth and Thomas,using simple water balance models described
McAlpine (1970),made estimates of growth periods a t several l o c a t i o n s
h i n and adjoining the study area.
The incidence of growth periods closely r e f l e c t s the r a i n f a l l
A t Nappamerrie i n t h e dry south-western s e c t o r an average of a
ime.
t l e less than 3 growth periods occur i n a year.
I n the north-eastern
t o r an average of 4 t o a l i t t l e l e s s than 5 growth periods can be
ected annually.
More than 60% of t h e growth p e r i o d s h a v e a duration
ss than 4 weeks.
TOPOGRAPHY
The area slopes both t o t h e west and t o t h e south w i t h a l t i t u d e s
ng from 373 m i n the north-eastern corner t o less than 54 m a t Cooper
e a r Nappa Merrie (Fig. 3.3).
The area comprises a s e r i e s of four
l e s s p a r a l l e l ranges separating the catchment areas of the major
I n the e a s t t h e W r i a r t y Range forms t h e divide between Paroo
rego catchments.
However i n the v i c i n i t y of Eulo-Cunnamulla t h e
becomes very degraded loosing i t s i d e n t i t y and a continuous b e l t of
l i n k s the two systems.
The Willies Range forms the catchment
r y of t h e Bulloo and P a r w Rivers both of which a r e major drainage
ms.
Further west t h e Grey Range separates t h e Bulloo River catchment
the Cooper Creek-Wilson River catchment, t h e Wilson feeding i n t o
Creek.
The a r e a west of the McGregor Range i s drained by the
A major fekture of t h e topography i s t h e complex drainage system
d by t h e l o c a l water courses i n association w i t h the major systems
i s i n g t h e Cooper and Kyabra Creeks and t h e Wilson, Bulloo an3 Paroo
s.
The Wilson catchment i s the only one of t h e main systems
ained within t h e study a r e a , t h e headwaters of a l l o t h e r s being outside.
red i n the T e r t i a r y
ediments were deeply w
Since then, T e r t i a r y l a t e r i t i c developments and Quaternary
s have obscured t h e o r i g i n a l sediments i n many areas.
The basement rocks a r e low grade metamorphics intruded by g r a n i t e
e Eulo Ridge, b a s a l t s i n the north-west of t h e Q u i l p i e sheet and
aleozoic c l a s t i c s .
Localized outcrops of the g r a n i t e basement occur
e s t of Eulo.
The Cretaceous Winton Formation which comprises mainly mudstones,
and f e l o p a t h i c sandstones ( i n p a r t calcareous) and minor developf coal, i s the most common outcropping u n i t i n t h e area.
These
t s a r e of f r e s h water o r i g i n formed under f l u v i a t i l e and paludal
The Mesozoic sedimentary rocks were folded i n t h e Late Cretaceous,
olding continuing throughout t h e Cainozoic i n t o recent times.
The
retaceous land surface was l a t e r i t i z e d and subsequently eroded
l y t h e lower p a r t of t h e l a t e r i t e p r o f i l e , comprising chemical1
Winton Formation, remains i n places.
Some
s l i g h t foldin
y erosion a l s o probably occurred t o give r i s e t o these v
s of these a l t e r e d Cretaceous sediments.
During the e a r l y T e r t i a r y , r i v e r d e p o s i t s were l a i d down on this
face.
T e r t i a r y gravels and sands were consolidated t o form
t e s and sandstone.
orm s i l c r e t e .
The upper sandstone beds were s i l i c i f i e d i n
During the l a t e T e r t i a r y t h i s s u r f a c e was warped
folding with associated f a u l t i n g .
Erosion removed l a r g e t r a c t s
a n t rocks p a r t i c u l a r l y from a n t i c l i n a l areas ( d u r i c r u s t ) on the
hills.
Synclinal depressions i n the land surface were i n f i l l e d
t s , muds and sands, building up l a r g e areas and thicknesses of
s a s subsidence continued i n downwarped areas i n t o t h e Quaternary.
Thick Quaternary alluvium covers over 25% of t h e area and these
i t s a r e mainly associated w i t h flood p l a i n s of t h e major drainage
Dune and s h e e t sand cover large areas i n the south an8 the
.
These sands a r e derived from t h e weathering of T e r t i a r y rocks and
i t i s e d sandstones.
S i l c r e t e gravel mantles a r e a l s o widespread.
These mantles a r e
oped by t h e erosion of t h e T e r t i a r y s i l c r e t e beds and t h 8 r e d i s t r i b n of this material.
the f r e s h Cretaceous sediments b u t
p a l l i d zones a r e exposed.
p l a i n s occur about t h e margins of t h e
and a l s o cover l a r g e t r a c t s of a l t e
p a r t l y dissected.
They a r e made up of
t e and weathered mantle d e t r i t u s w i t h s o f t e r Winton
i n somevalley f l o o r s .
Stony red e a r t h s a r e t h e most
mantle of s i l c r e t e gravel generally covers these
It of complete s t r i p p i n g of t h e
Formation which has weathered t o form cracking c l
i s s e c t e d r e s i d u a l s and on t h e lower scarps g i v
epth of these deposits
0 m.
v a r i e s from l e s s than 30 m
I t has been deposited a s a l l u v i a , mantled
Red e a r t h s a r e t h e most common s o i l s .
t h e drainage l i n e s , on associated flood p l a i n s and i n lakes.
a of t h e l o c a l streams tend t o be mixed c l a y , s i l t and
s e c t i o n s becoming more sandy i n the upper s e c t i o n s where
f t h e major r i v e r s tends t o be mainly clays.
t u r e of t h e Paroo and Bulloo Rivers and Cooper Cre'ek i s
l l i n g with f i n e material a l s o occur.
LAINS:
The sand-plains a r e of a e o l i a n o r i g i n .
0th a l l u v i a l p l a i n s and upland surfaces.
They have developed
Sand-plains developed
a l l u v i a a r e usually interspersed w i t h claypans and a l l u v i a l deposits.
north, sand p l a i n s cover s i l c r e t e capped dissected r e s i d u a l s and
p l a i n s b u t i n t h e south they occur mainly over gently undulating
r e t e covered surfaces.
These sand p l a i n s may e x h i b i t l i m i t e d dune
ion.
ELDS:
This u n i t i s spread over old a l l u v i a and t h e lower slopes of
t i n g p l a i n s mainly west of t h e Grey Range.
The dune form v a r i e s ;
o s t common form i s the r e t i c u l a t e dune which i s common i n drainage
s b u t l o n s i t u d i n a l dunes a l s o occur.
The s o i l s of the area have been described and discussed by various
rs including P r e s c o t t (1931, 1944), Skerman (1947b), Northcote et a t .
),
Isbell e t
az. (1967) and Dawson and Ahern (1973, 1974).
The r e c e n t
e s by Dawson and Ahern a r e t h e m o s t comprehensive and d e t a i l e d
able and a r e t h e b a s i s of t h i s account.
s o i l development has been strongly influenced by l i t h o l o g y , t h e
r i n g s t a t u s of parent material and p a s t geomorphic cycles.
The major
h i c processes involved i n producing the present landscape have been
emical a l t e r a t i o n of Cretaceous sediments during the T e r t i a r y , t h e
quent erosion of t h a t landscape exposing f r e s h sediments and t h e
i t i o n of d e t r i t u s on outwash p l a i n s .
Past climate and drainage a l s o
ad s i g n i f i c a n t e f f e c t s on s o i l development and d i s t r i b u t i o n .
The cracking c l a y s a r e t h e m o s t productive s o i l group i n t h e
The red e a r t h s of t h e sand-plains and the s i l i c e o u s and earthy
of t h e
dunefields a r e not a s productive.
CRACKINGCLAYS:
These s o i l s occur both i n alluvial. s i t u a t i o n s and on
a t i n g downs.
-
via.
Grey c l a y s a r e associated w i t h poorly drained areas and t h e
p l a i n s of major streams.
These s o i l s a r e extensive and bestdeveloped
flood p l a i n s of Cooper Creek and t h e Paroo and Bulloo Rivers.
The
a r e deep, frequently gilgaied and crack widely when .dry1'.
Brown clays tend t o be associated with the l e s s frequently
ed a l l u v i a .
S o i l r e a c t i o n of these s o i l s i s n e u t r a l a t t h e
c e tending t o be more a l k a l i n e a t depth.
The surface s o i l s a r e non-
Ironstone shot
The deep, red eaxths a r e massive and porous.
commonly present on t h e surface and throughout the p r o f i l e .
The
s a r e predominantly stxongly acid t o s l i g h t l y a c i d a t the surface
coming l e s s a c i d with depth.
The s o i l s a r e non-sodic and non-saline
Nutrient l e v e l s a r e low, with l o w t o very low available
roughout.
osphorus, organic carbon and nitrogen, exchangeable potassium i s low
fair.
Available s o i l water capacity i s low.
The shallow red e a r t h s occur i n the upper p a r t of t h e landscape
sociated with dissected tablelands, mesas and b u t t e s .
s s i v e w i t h an earthy f a b r i c .
The s o i l s a r e
Surface stone cover is common and ironS o i l r e a c t i o n ranges
one shot and gravel occur throughout the p r o f i l e .
om extremely acid t o medium acid.
Nutrient l e v e l s are very low f o r
i l a b l e phosphorus, organic carbon and nitrogen.
Available s o i l water
a c i t y i s low t o very low.
Y RED EARTHS:
These s o i l s a r e associated with the sandplains found
movement of aeolian sand over both the Tertiary upland s u r f a c e and
ypans.
The s o i l s occurring over t h e upland s u r f a c e are deep and the
1 r e a c t i o n i s n e u t r a l t o acid.
Those developed over clayplains a r e
e r a t e l y deep w i t h n e u t r a l t o a l k a l i n e s o i l r e a c t i o n trends and with
ruginous hardpans.
ic
The s o i l s a r e massive, porous non-saline,
and s u b j e c t t o erosion.
non-
Nutrient l e v e l s a r e low with low t o very
,'j
.a
,I
I4
s8
a v a i l a b l e phosphorus, organic carbon and nitrogen, exchangeable
assium ranges from low t o f a i r .
Y SANDS:
Available s o i l water capacity i s low
These s o i l s occur i n the dunefields and r e l a t e d sandplains
a r e c l o s e l y associated with s i l i c e o u s sands.
south of Cooper Creek.
They a r e extensive west
The earthy sands have a s i n g l e grain s t r u c t u r e
a r e loose when disturbed but may be massive i n
situ due t o bridging
P r o f i l e s a r e usually deep
t h e sand p a r t i c l e s by small amounts of clay.
Very deep with hardpans occurring infrequently.
Nutrient l e v e l s a r e
t o very low, with very low available phosphorus, organic carbon and
ogen.
Available s o i l water capacity is vexy low.
ICEOUS SANDS:
~ f i e s es o i l s a r e associated w i t h the dunefields.
Oussands a r e loose and s i n g l e grained.
.
The
They a r e mainly quartzose
All n u t r i e n t l e v e l s a r e very low a s i s t h e a v a i l a b l e s o i l water
use surveys i n Australia f o r many years.
The present
e term land form instead of land u n i t .
Coaldr
o a s t a l Queensland based h i s survey on these con
rm landscape i n place of t h e complex o r compound land system.
The b a s i c methodology of t h i s survey i s a s l i g h t modification of
tegrated land system approach of C h r i s t i a n and StewKt.
In past
t h e land system description has been t h e important d e s c r i p t i v e
re.
I n this survey more emphasis has been placed on t h e description
sessment of t h e land u n i t s and more q u a n t i t a t i v e d a t a have been
ed from each land u n i t .
Land use o r p o t e n t i a l land use was a l s o
ered i n defining land u n i t s .
Simultaneous with the c o l l e c t i o n of vegetation d a t a , other
list workers recorded d a t a on land fonn, geology, s o i l s and land
zation f a c t o r s .
This s i t e d a t a were then c o l l a t e d providiag a
hensive d e t a i l e d description f o r each u n i t .
SAMPLING
Although many d i f f e r e n t sampling techniques e x i s t they can be
ed i n t o two broad categories
- objective
approaches and subjective
survey of t h e study a r e a was undertaken
l a t i v e l y homogenous s i t e s were selected along t h e t r a v e r s e s
jective b a s i s avoiding obvious ecotones.
A s i t e was considered
i f on inspection t h e d i r e c t i o n and percentage slope were
d -/ariation within t h e association seemed more a r e s u l t of
an t h a t of s o i l heterogenity.
Vegetation d a t a recorded included major species p r e s e n t and
r a l fornation.
Tree and shrub d e n s i t i e s were estimated f o r most
Following c o l l a t i o n of d a t a and i n t e r p r e t a t i o n , the photomapping
vised i n l i g h t of experience obtained u n t i l a s a t i s f a c t o r y standard
ieved.
This completed t h e preliminary s t u d i e s stage.
After c r i f i c a l examination of t h e photomapping a number of
i c t e d length t r a v e r s e s were selected.
d from 115 kilometres.
The length of the t r a v e r s e s
These t r a v e r s e s were chosen
not only to
n sampling s i t e s within land u n i t p a t t e r n s b u t a l s o t o e s t a b l i s h
ionships between the land u n i t s .
Where p o s s i b l e t h e t r a v e r s e s were
p a t t e r n s were represented a t l e a s t t h r e e t i m
cated s o t h a
d t h e range
o p a t t e r n s were covered t o record p o s s i b l e
:ion.
t e s along t h e t r a v e r s e s were selected c a r e f u l l y
t h a t they were apparently homogenous and exhibited no major signs
f disturbance.
S i t e s were usually located a t l e a s t 40 m from t h e edge
the road t o avoid any roadside e f f e c t s .
DATA COLLECTION
Isolated
<1
1-5
5-10
10-20
20-30
30-50
Density varied g r e a t l y .
1
2
3
4
5
6
7
B e l t t r a n s e c t s (40 m x 10 m) were used
t o e s t a b l i s h t r e e and t a l l shrub density.
I n dense stands
where t h e b e l t t r a n s e c t was not p r a c t i c a l f o r t h e estimation of
t r e e and t a l l shrub d e n s i t i e s and f o r low shrub d e n s i t i e s p l o t s
(5 m x 5 m) r e p l i c a t e d 4 times were used.
I n very dense stands,
t h e p o i n t centred q u a r t e r method ( P h i l l i p s , 1959) f o r determining
t r e e density was used.
ve f o l i a g e cover:
Estimated v i s u a l l y with randomized checking
using a modified periscope t o ensure consistancy.
e r class:
Estimated v i s u a l l y w i t h p e r i o d i c c ki+cking using c a l l i p e r
t o ensure consistancy.
tage dead t r e e s :
eration:
Recorded when density counts were undertaken.
Evidence of regeneration of s p e c i e s was recorded a s well as
t h e agent involved i . e .
vegetative means.
suppressed seedlings o r regeneratibn by
Quantitative measurements were not recorded.
.4XONOMIC AND OTHER CATEGORIES USED.
The species i s t h e b a s i c taxon used i n describing the.vegetation.
S
no r e c e n t l y published account of t h e f l o r a of t h e a r e a a v a i l a b l e .
l a t u r e followed is t h a t used by the Queensland Herbarium (Cataiogue
ts, unpublished d a t a )
.
on p r o j e c t i v e f o l i a g e cover and height and/or
l e s t stratum.
The t a l l e s t stratum i s not
c h a r a c t e r i s t i c nor does i t always d e f i n e the
o characterize t h e association and not necessarily the t a l l e s t
.
Nomenclature of s t r u c t u r a l formations follows t h a t proposed by
rejective f o l i a g e cover of l e s s than t e n percent.
.2
S t r u c t u r a l formations recorded i n t h e study area.
Projective f o l i a g e cover of C h a r a c t e r i s t i c Stratum
open woodland
low open woodland
open hummock
open sedgeland
herbland i s used t o r e f e r t o associations i n which speciesion and abundance i s dependent on seasonal conditions and a t any
e grasses o r forbs may predominate.
The scheme put forward by
has been a major development; confusing and c o n f l i c t i n g nomenclature
en eliminated and t h e scheme has been more widely accepte* than any
t there i s need f o r f u r t h e r divisions i n the height categories of
ands and a re-examination of t h e l i m i t s of p r o j e c t i v e f o l i a g e cover
10%l e v e l .
Data c o l l e c t e d suggested t h a t t h e r e is a need f o r four
s of shrublands and not two a s proposed by Specht.
r a t e s t h e suggested sub-division of shrublands.
Table 4.3
Although these
4.3
Proposed shrubland c l a s s i f i c a t i o n
Proposed Nomenclature
Example associations
dwarf shrubland
Arthrocnemvm spp. ;
Cassia phyZZodinea
low shrubland
shrubland
Chenopodiwn auriconnun;
Acacia s towardii
Acacia aneura
t a l l shrubland
Acacia aneura
o r i e s were recorded f o r consistancy with other workers only the two
e s recognized by Specht were used i n the description of the vegetat
A t o t a l of 242 s i t e s were sampled i n d e t a i l and 603 observational
s were recorded.
These were adequate t o represent the major vegetation
s b u t d i d not represent a11 minor v a r i a t i o n s .
Two minor types were not
rved during f i e l d work (Silcock, pers. comm.) but these have been
The time spent i n recording d a t a a t observational sites varied
l e s s than one minute up t o twenty w i t h an average time of about 15
tes.
The time spent i n recording data a t d e t a i l e d s i t e s ranged from
than 1 minute on scalds t o 85 minutes on a complex a l l u v i a s i t e .
-.
The l a r g e v a r i a t i o n i n time is a
average time was 35 minutes.
e c t i b n of t h e complexity and d i v e r s i t y of the f l o r a a t various s i t e s .
Some workers (e.9. Lambert
and Dale, 1964) suggested t h a t
rding only presence d a t a r e s u l t s i n a l a r g e saving of time Vith l i t t l e
i n analyses.
I n this survey the t i m e a c t u a l l y spent a t s i t e s
ording d a t a reprffiented about 30% of t h e t o t a l workable f i e l d time, t h e
nder being used i n t r a v e l l i n g .
I f q u a n t i t a t i v e d a t a were not
ected time spent i n d a t a recording a t s i t e s would have been approximately
of t o t a l workable f i e l d hours.
This would have r e s u l t e d , i n an o v e r a l l
ng of only 8%i n time, a reduction of about 10 f i e l d days.
-
-
OF METHODS
Techniques used were s a t i s f a c t o r y f o r t h e purpose of t h e
rcise.
me v i s u a l assessments of d a t a were a c c u r a t e enough
number of s i t e s both d e t a i l e d and o b s e r v a t i o n a l w e r e s u f f i c i e n t .
The f l o r i s t i c d i v e r s i t y of woody s p e c i e s only could be
s s e d f ~ o mthe methods used.
I t i s considered t h a t t h e use of a
, are
a l s o included i n t h i s group.
The
ading p l a n t s , whose a e r i a l p a r t s d i e during
l a n t regenerates by vegetative regrowth when moisture
includemany of t h e perennial grasses such a s Aristida SpP.
The r e s u r r e c t i o n p l a n t s such as Tripogon
rostis spp.
mis (family poaceae) and FimbristyZis dichotoma (family
Resurrection p l a n t s have
e ) a l s o belong t o t h i s category.
r e f u l l y discussed by Graff and Latz (1978).
e n n i a l £orbs may a l s o f a l l i n t o t h i s group.
Some sub-shrubs
The t h i r d grouping,
a 1 drought evading p l a n t s o r ephemerals complete t h e i r l i f e
b r i e f periods when moisture l e v e l s a r e adequate and survive t h e
d s a s dormant seeds.
The ephemerals include many members of
y Asteraceae such as Brachyscome spp. and CaZotis spp. b u t a l s o
r a s s i a c e a e and Apiaceae contain a l a r g e number of ephemerals.
hemerals appear i r r e g u l a r l y and t h e i r germination responses are
programmed t o d i f f e r e n t environmental cues (Mott 1972, 1974a.
, Mott
and McComb 1974)
.
. .
I f t h e r e a r e f e a t u r e s t h a t characterize t h e vegetation they
be t h e high l e v e l of development of phyllodineous species of
a and t h e l a r g e number of f a m i l i e s , approximately 37% of families
ded, represented by a s i n g l e genus including 28 families represented
s i n g l e species.
Sclerophylly i s the outstanding c h a r a c t e r i s t i c of
a l i a n f l o r a and a phyllode, an adaption of the p e t i o l e of t h e l e a f ,
s e n t i a l l y a sclerophyll organ.
Phyllodes are not r e s t r i c t e d t o
a t i o n of a r i d a r e a s b u t modifications t o phyllodes do a s s i s t p l a n t s
urvive i n regions subject t o moisture s t r e s s f o r extended periods.
f i c a t i o n s included p o s i t i o n a l arrangement, s i z e , glaucesence and
escence.
Modifications t o phyllodes even occur within species a s
u s t r a t e d by Acacia anewa.
I t s phyllodes become elongated up t o
cm long and 0.2 cm wide i n more x e r i c s i t u a t i o n s compared with 2 cm
and 1.2 cm wide i n the e a s t .
Phyllodes a r e not r e s t r i c t e d t o
ia and o t h e r genera f o r example Cassia a l s o e x h i b i t this phenomenum.
f l o r a a l s o contains i n t e r e s t i n g paleotropic representatives but t h i s
ypical of o t h e r a r i d regions throughout the world such as the
nan Desert i n America (Axelrod, 1979).
Lequminosae
Myoporaceae
Chenopodiaceae
Chenopodiaceae
Chenopodiaceae
Amaranthaceae
Leguminosae
Cyperaceae
Asteraceae
Solanaceae
Asteraceae
Chenopodiaceae
Euphorbiaceae
Goodeniaceae
Species of t h e genus Acacia a r e t h e most f r e q u e s t l y occurring
t r e e s with a t o t a l of 29 species being recorded.
These species
cuous on most land types occurring a s a dominant o r codominant i n
c i a t i o n s covering approximately 63% of t h e t o t a l area.
Of the
c i e s recorded only Acacia aneura, A. caZcicoZa, A. cambagei,
, A.
petraea and A. stowardii a r e s i g n i f i c a n t i n terms of a r e a l
These s i x species e i t h e r dominate o r codominate 95% of the Acacia
ant associations.
A. aifleura i s t h e most widespread and i t i s the
o r codominant species i n 8 2 s i t e s out of 95 s i t e s where it was
Besides having a wide geographic range it t o l e r a t e s a wide
s o i l types from red cracking clays t o red s i l i c e o u s sands.
eloped on red earths.
A. c d a g e i i s widely d i s t r i b u t e d occurring
ow loamy s o i l 2 t o cracking clays.
soils.
It i s
1t o b t a i n s i t s b e s t development
A. petraea and A. stowardii a r e widespread on shallow s o i l s
ed with dissected r e s i d u a l s throughout the region.
A. tephgna
ensively developed outside t h e study area favours cracking c l a y s
A. calcicoZa is associated with
taceous sediments.
s t o loamy coarse sands i n t h e south-west of t h e region.
EucaZyptus i s not well represented.
Thirteen species
butE. cambageana, E. Zargiflorens, E. metanophloia,
carpa and E. tesseZZark a r e r e s t r i c t e d t o the e a s t of the region
genus
a t the western l i m i t of t h e i r range.
Of the remainder, only
heca, E. camaldutensis, E. ochrophtoia, E. temninatis and
Znea dominate o r codominate p l a n t associations of any s i g n i f i c a n t
Of these E. microtheca i s t h e comrnonest associated w i t h t h e
land zones b u t E. temninalis would be t h e most widespread
ing on most s o i l types.
Other species including E. ezserta,
etiana and E. papuana have r e s t r i c t e d h a b i t a t preferences the
ng associated w i t h sand p l a i n s and t h e o t h e r s with dissected
Eucalyptus lends support t o t h e observf Perry and Lazarides (1962) t h a t i n general EucaZyptus spp. a r e
als.
The d i s t r i b u t i o n of
e l l represented i n t h a t p a r t of A u s t r a l i a north of the southern
--,
---
EremophiZa spp. a r e w e l l represented w i t h 21 taxa present out
e 24 recorded f o r Queensland.
They reach t h e i r b e s t expression i n
u s Acacia aneura associations although Eremophila species occur i n
t a l l habitats.
Some species a r e very s e l e c t i v e i n t h e i r h a b i t a t
rnaedonne7,Zii occurring only on extended flanks of dunes and
nsmithii confined t o very r e s t r i c t e d s i t e s associated with dissected
uals.
E. macutata is widespread growing on a range of s o i l types
a s E.
cracking c l a y s t o s i l i c e o u s sands.
Several species a r e troublesome
because of t h e i r capacity f o r rapid population i n c r e a s e s , t h k i r
ion t o a d r i e r h a b i t a t and a b i l i t y t o escape grazing because of
r non a c c e p t a b i l i t y t o domestic stock.
Undoubtedly
E. gilesii which
rs red e a r t h s i s t h e most troublesome and m o s t s i g n i f i c a n t i n terms
E. bowmanii, associated with sandy red e a r t h s and
y sands, and E. mitcheZZii, associated w i t h clays and t e x t u r e
a s t s o i l s mainly i n t h e e a s t , a r e o t h e r troublesome species. Cassia
e a l extent.
' e s a r e t h e o t h e r shrubs well represented i n the region.
s are not
-
yene~q5
-,,,,e,k~ , , dabr\dcie*.
Chenopod
Unlike southern p a r t s of a r i d
.
Grasses a r e numerous
o c c u r r i n g i n almost a l l a s s o c i a t i o n s
Eragrostis has t h e l a r g e s t r e p r e s e n t a t i o n with
There were 15 s p e c i e s of Aristida c o l l e c t e d b u t
p e c i e s recorded.
a r e a occupied by A r i s t i d a spp. i s more e x t e n s i v e than t h e a r e a
Because of t h e s e f a c t o r s Aristida spp.
i e d by Eragrostis spp.
some f o r b l a n d s .
d be considered t h e most important g r a s s genus w i t h i n t h e a r e a . Triodia
owii occupies e x t e n s i v e a r e a s i n t h e west being r e s t r i c t e d t o
eous sands and e a r t h y sands a s s o c i a t e d w i t h t h e d u n e f i e l d s and
lains.
AstrebZa pectinata a l s o occupies e x t e n s i v e a r e a s ,
r i n g t h e cracking c l a y s on t h e u n d u l a t i n g downs.
Some s p e c i e s
a s Eragrostis austraZasica and ZygochZoa paradoxa a r e s e l e c t i v e i n
s i t e requirements favouring mobile dune c r e s t s and claypans o r
s r e s p e c t i v e l y b u t many g r a s s e s a r e semi-arid t o a r i d wides.
Forbs a r e abundant w i t h l a r g e genera i n c l u d i n g SCZeroZCena,
t e x , Maireana and Sida.
Members of Asteraceae a r e found through-
t because of t h e i r ephemeral n a t u r e t h e i r presence i s dependent
ourable seasonal conditions.
ENDEMIC SPECIES
The p r o p o r t i o n of genera and s p e c i e s r e s t r i c t e d t o t h e a r e a i s
mely low.
Only one genus XerothamizeZZa and f i v e s p e c i e s
rvijoliiim, EremophiZa ZinsnrCtI~ii,PtiZotus remot~ij7orus ( a l l
r i c t e d t o d i s s e c t e d residuals),Crii'zun p e s t i z e n t i s ( a l l u v i a of major
ams) and Acacia amophita (sand s h e e t s o v e r l y i n g c l a y ) f a l l i n t o
category.
S t e b b i n s (1952) has given reasons why p l a n t e v o l u t i o n
be r e l a t i v e l y r a p i d i n a r i d and semi-arid r e g i o n s .
Laen moisture
i m i t i n g o t h e r f a c t o r s have a g r e a t e r e f f e c t on t h e f l o r a and
a t i o n than i n r e g i o n s where moisture i s adequate.
Also semi-arid
t e s with t h e i r r e g i o n a l d i v e r s i t y promote t h e d i v i s i o n 0f.medium
l a r g e s i z e d p o p u l a t i o n s i n t o s m a l l e r u n i t s which a r e i s o l a t e d from
o t h e r b u t can exchange genes by occasional
l a t i o n s t h a t may g i v e r i s e t o new t a x a .
migration and e s t a b l i s h
Finally i n dry regions
d i f f e r e n t s p e c i a l i z e d v e g e t a t i v e s t r u c t u r e s ( e . g . reduced l e a f
I
I
I
ii
I
Xanthiwn s
downs.
ems mainly i n t h e e a s t with
Nicotiane gZauea i s a l s o associated with a l l u v i a but, i t s
poradic.
Prosopis flexuosa a n a t i v e of South America
t o t h e Bulloo a l l u v i a i n t h e v i c i n i t y of Quilpie b u t has
1 t o become a troublesome woody weed.
The grasses were a l l
p a s t u r e species and a r e found mainly on sandy red e a r t h s
disturbed a r e a s b u t none of these grasses a r e very wide-
hrus ciziaris a l s o occurs on t e x t u r e c o n t r a s t s o i l s .
the region i s towards t h e extremities of t h e favoured
C. ciziaris i s
Germination and establishment of C. ciziaris i s
Once established C. ciZiaris i s capable of
e f o r C. ciziaris probably accounts f o r why
spread.
factor.
l i m a t i c conditions.
@1TH SIMILAR REGIONS WITHIN AUSTWIA
a marked s i m i l i a r i t y i n the composition of the f l o r a
t h a t of c e n t r a l Australia a t t h e family leve
i s t of c e n t r a l Australian p l a n t s prepare
t h e p l a n t s recorded f o r t h e Alice Springs region
r y and Lazarides (1962) with t h e l i s t f o r t h i s area t h e same f o
es contribute
most t o t h e f l o r a i n a l l regions.
The check l i s t
e Simpson Desert National Park i n Queensland (Boyland, 1970) a l s o
l e c t s similar trends.
There appears t o be a d i f f e r e n c e i n the
o s i t i o n of t h e f l o r a of t h i s region with t h a t of the Simpson Desert
presented by Crocker's c o l l e c t i o n s (Eardley, 1946).
I n those
l e c t i o n s t h e l a r g e s t representation of species i s by t h e families
uminosae, Chenopodiaceae, Myoporaceae and Amaranthaceae.
sons f o r the apparent d i f f e r e n c e can be offered.
Several
Crocker's
i o n s were few i n number and it i s obvious not a l l material was
ed.
Crocker probably concentrated on c o l l e c t i n g specimens which
e new species o r those not r e a d i l y recognized.
The absence of
ae and Asteraceae may be explained by t h e f a c t t h a t many of these
es are ephemerals and t h e i r presence is governed by seasonal
itions.
I n a check l i s t of t h e flowering p l a n t s of the Simpson
r t and i t s immediate environs prepared by Symon (1969) t h e four
l i e s with t h e l a r g e s t representation were t h e same a s i n t h e study
b u t i n the order Leguminosae, Chenopodiaceae, Asteraceae and
The comparison of stands i n terms only of t h e species present
t reference t o t h e abundance of species i s a crude and i n s e n s i t i v e
of c h a r a c t e r i z a t i o n ( ~ h s m i t h 1964).
,
However on a l a r g e s c a l e
a p l a n t geography viewpoint, comparison of species l i s t s a r e
a b l e and give an objective assessment of t h e degree of s i m i l a r i t y
een f l o r a s of various regions.
Comprehensive lists of t h e species of various regions f o r
a i l e d comparison a r e not r e a d i l y available.
Only t h e l i s t s compiled
Chippendale (1959), Symon (1969) and Boyland (1980) of Centrala l i a , t h e Simpson Desert and an area immediately north of t h e study
respectively a r e s u i t a b l e (Fig. 5.1)
.
Comparisons a t the s p e c i f i c l e v e l were c a r r i e d out by two methods
proposed by Sorensen (1948) and t h e other formulated by ~ C e s t o n
62a, 196233) and' used by Rzedowski (1973) i n s t u d i e s on t h e Mexican
ra.
These two techniques were chosen because t h e former i s one of
more widely applied indices of s i m i l a r i t y according t o ~ u e l l e r - D ~ m b ~ i S
Ellenberg (1974b)and t h e l a t t e r attempts t o overcome t h e problem of
l i s h i n g r e l a t i o n s h i p s between f l o r a s of l a r g e a r e a s not necessarily
Ir
where L i s t h e a c t u a l number of species
common t o A and B.
.cients and indices of s i m i l a r i t y f o r t lne v a r i o
t h e study a r e a a r e given i n Table 5.4.
Lents and i n d i c e s of s i m i l a r i t y f o r t h e various
Total
Species
Number i n
Sample
~ d e ofr
common
species
C o e f f i c i e n t of
similarity
CS
Inaex of
similarity
ISS
1 Australia
f o r both CS and ISs shows t h e existence of an evident f l o r i s t i c
t i o n between t h e study area/WARLUS I T and the Central Australia/
The high l e v e l of s i m i l a r i t y between WARLUS I1
on Desert regions.
e study a r e a i s not unexpected a s they a r e s i t u a t e d adjacent t o
e r and enjoy t o a l a r g e degree a s i m i l a r range of h a b i t a t and
c conditions.
The f a c t t h a t the CS and ISs were not higher i s
o t h e more ext-ensive development of t h e undulating downs and t h e
e (Acacia cambagei) l a r d s i n t h e e a s t and north-east of W E & U S II
The Cential Australian and Simpson Desert regions both showed
degree of s i m i l a r i t y .
The ISs f i g u r e s e s p e c i a l l y can only be
i n broad terms a s indicated by Mueller-wmbois and Ellenberg (19741
ated t h a t i n comparing s i t e s , i n d i c e s l e s s than 25% r e f l e c t
t i c d i s s i m i l a r i t y and those g r e a t e r than 50% a r e s i m i l a r f o r a l l
i c a l purposes.
I n vi@w of t h i s , the f i g u r e s derived f o r t h e IS,
n t r a l A u s t r a l i a and t h e Simpson Desert can be considered equal.
t e r e s t i n g f e a t u r e of these f i g u r e s f o r t h e Simpson Desert and t h e
1 Australian region is t h e i r s i m i l a r i t y .
A lower l e v e l
t h e phytogeography of Australia,
d a t a , Burbidge (1960) places
r e a (approximately 95%) i n t h e Eremaean Zone.
The
l i e s i n the Tropical-Eremaean
3 area.
According t o Burbidge t h e climate of t h e Eremaean
r i a b i l i t y of t h e r a i n f a l l both
y.
The Zone i s crossed obliquely by t h e junction
ummer and winter r a i n f a l l systems.
The f l o r i s t i c s of the
not a s c l e a r l y defined with ranges i n Central Australia a c t i n g
f o r northern and southern elements.
Apart from such refugia,
ion from north t o south i s probably
e n t s and possibly a l s o day length
11.
Burbidge considers t h a t the Eremaean f l o r a
r i g i n a t e d from a c o a s t a l and l i t t o r a l type involving elements
grated t o t h e Australian region a s e a r l y a s the Cretaceous but
s t h a t many of t h e c h a r a c t e r i s t i c elements may be of r e l a t i v e l y
velopment.
The interzone 3 i s broadly t h e 'black s o i l ' system
vers much of c e n t r a l Queensland.
The general representation is
he i n t e r s e c t i n g r i v e r systems not primarily because
cause of edaphic d i f f e r e n c e s and
nce of deep alluviums.
The interzone i s not c l e a r l y defined.
More recently i n a much broader study using dominant and
e r i s t i c species of t h e vegetation, Doing (1970) a l l o c a t e d
mately 68% of t h e area t o t h e Eastern Mulga P r o v i n z c e , about 20%
Eastern Desert Provinz.ce and t h e remaining 12%t o t h e Northern
rovin.:-e.
The blulga ProvinCce i s dominated by
Acacia aneura
d i v i s i o n s i n t o northern and e a s t e r n is based on climate with the
f t h e Northern P r o v i n Z ~ eoccurring i n t h e t r o p i c s and t h e Eastern
Z c e being confined t o the subtropics.
The Desert Provin"_.ce i s
ribed a s a more o r l e s s vegetated but l a r g e l y t r e e l e s s area, the
n Desert Provin.:;ze
being the most a r i d region i n Australia.
rs within Australia appear t o have largelyGvciiuokedthis work of
Both the spproach of Bwbidge and Doing a r e very broad'scale.
boundaries erected by bothworkers do have
nce i n the region.
The boundary a s delineated by Burbidge c u t s
e north-eastern corner, t h e most moist region of the area.
This
neura low woodland t o t a l l shrubland frequently
ea emerging and i n places E. populnea dominates.
a t i o n s occur elsewhere i n t h e a r e a these associations
i n the north-east.
Doing's boundaries a r e a l s o
e s t e r n boundary of the Eastern Mulga Provin,;ce
ms the western l i m i t s of t h e major Acacia anewa
ominant associations.
The tongue of t h e Northern Mulga
?ri?vtn<a
cides approximately with t h e major channel country and t h e undulating
Whilst it does not d e l i n e a t e
ny downs land zones.
o c i a t i o n s a s t h e name of t h e Provin
Acacia anezira
ce suggests, the grouping
land types mentioned is not u n r e a l i s t i c on a broad
t h e name applied t o the P r o v i n r c e f o r t h i s area
rranted.
The region defined by Doing as t h e Eastern Desert
v i n 3 c e supports Trtodia basedowii open hummock grassland with forb
the west and Acacia s t m a r d i i
st.
+ A.
anemu low open shrubland i n t h e
Generally this region supports sparse vegetation and althoug
o r i s t i c s and s t r u c t u r a l forma
a c t i c a l and acceptable.
Apart from
s
othe
d i v i d e Queensland i n t o phytogeographic regions o r natural ecological
ions was t h a t of Laut e t aZ. (1975).
I n an attempt t o provide a
liminary r e g i o n a l i z a t i o n of t h e Australian biophysical environment,
e t aZ. divided A u s t r a l i a i n t o 309 biophysical regions based t o a
e degree on c l i m a t i c d a t a and r i v e r watershed areas.
The r e s u l t a n t
ions erected were intended t o form a b a s i s f o r organizing d e t a i l e d
o l o g i c a l and land use information.
~t was thought t h a t these groups
uld enable a f f i n i t i e s within t h e region and outside t h e region t o be
The study area i s covered by twelve ( 1 2 ) o r p a r t thereof of
s e biophysical regions.
According t o Laut e t aZ. c3.975) s e v e r a l
these biophysical regions have s i m i l a r predominant vegetation
n i t i e s and i f these regions a r e grouped on t h a t b a s i s then.seven
groupings emerge (Table 5.5).
The vegetation d a t a base i s broad a s can be seen from Table 5.5
d inaccurate i n places.
This would permit only generalized conclusions
be drawn a t the b e s t which could be only t r e a t e d with reservation. The
cept of these regions i s sound b u t t h e value of t h e regions a s
l i n e a t e d by Laut e t az. i s questioned.
SOURCES OF THE FLORA
Until t h e f o s s i l record i s b e t t e r known any attempt t o account
e present composition of t h e f l o r a has t o be l a r g e l y conjectional.
amination of t h e present day vegetation.
For t h e purposes of examining t h e f l o r a a s a whole discussions
be confined i n i t i a l l y t o t h e generic l e v e l .
Following t h e s e
r n s within the f l o r a r e f l e c t e d a t t h e generic l e v e l a l s o apply a t
Some genera appear t o reach t h e i r b e s t expression i n a s p e c i f i c
matic geographic region, some genera tend t o favour c e r t a i n geographic
e a r e other genera nhich show no a f f i n i c y f o r any geographic o r
Discarding t h e 9 a l i e n genera recorded f o r the area, t h e
aining 285 genera l i s t e d have been grouped i n t o t h e geographic element
Number of genera from the geographic elements recognized
l e 5.6
-
demic t o area
stralian
no climatic
Cosmopolitan
Cosmopolitan
s t r a l i a n - tropical
Stralian
temperate
stralian
eremae4n
smopolitan
no c l i m a t i c
North American
South American
-
-
-
temperate
- eremaean
r e l a t i o n s h i p s e x i s t between t h e broad h a b i t a t s
groups.
Of t h e species which favour t h e t e r t i a r y remnants,two
belong t o t h e JuZifZorae.
itat.
Almost a l l t h e JuZ<florae occur on
The t e r t i a r y remnants a r e t h e most ancient of t h e land
present i n t h e study area and the JuZifZorae a r e postulated
he e a r l i e s t of t h e Acacia groups.
A. rigens (Ph?inerves)
i s r a r e i n the area and i s associated with the t e r t i a r y remnants
l l y favours recently degraded o r reworked sands i n the region where
hes i t s b e s t expression.
c u l t t o explain.
Its occurrence i n t h e study a r e a i s
A. microsperma (PZwinsrues) i s associated with
wer slopes of dissected r e s i d u a l s occurring i n an interzone
s h e e t s and t h e residuals and i s not widespread.
on sands overlying clays.
between
Further e a s t it
A. ensifozia (PkyZZodineae), t h e other
l e s i n this broad h a b i t a t group, occurs on t h e recently eroded breaknd is endemic t o t h e area.
t o occupy a vacant niche.
It i s suggested t h a t t h i s species
On t h e other hand, a high proportion
e species belonging t o the PhyZlodineae favour the dunefields and
sheets.
This is t h e most r e c e n t h a b i t a t and over half t h e
odineae the suggested most recently derived group of Acacia favour
abitat.
I t appears these d a t a lend strong support f o r Pedley's
ested sequence of development.
Pedley i n deriving h i s sequence
h i s work on p o l l e n grains and c h e d c a l d a t a t o a l a r g e degree and
, habitat
and ecology were not taken i n t o consideration.
An examination of t h e geographic regions of o r i g i n and t h e
s a l s o r e v e a l s i n t e r e s t i n g p a t t e r n s with JuZiflorae favouring the
thern eremaean o r t r o p i c a l region.
This i s f u r t h e r supporting
nce f o r t h e e a r l i e r hypothesis t h a t t h e o r i g i n a l f l o r a of the study
exhibited t r o p i c a l a f f i n i t i e s .
I t i s a l s o i n t e r e s t i n g t h a t tQe
f l o r a e has t h e highest percentage of endemics suggesting a longer
f o r speciation.
The Ph2inemes, with a high l e v e l of species
th t r o p i c a l a f f i n i t i e s occupying more recently developed h a b i t a t s
ared with t h e t e r t i a r y remnants, support t h a t an invasion of species
t h t r o p i c a l a f f i n i t i e s occurred a t a l a t e r time.
This information
s more support t o , t h e e a r l i e r hypothesis of how t h e present day
o s i t i o n of t h e f l o r a may have eventuated.
I f the a r e a l e x t e n t of the species comprising the t h r e e groups
A. ~aneuraand
stowardii would be t h e main contributors w i t h A. brachystmhya and
e considered then the JuZifZorae occupy the most land.
6. VEGETATION
Changes may be due t o
Vegetation of t h e area is dynamic.
t i n g v a r i a t i o n s of c l i m a t i c f a c t o r s and modifications of h a b i t a t s .
'nclude progressive changes due t o cumulative e f f e c t s of l i t t e r o r
e s caused by s o i l erosion and accidental, purposeful o r n a t u r a l
trophes.
The present s t a t u s of t h e vegetation i s a r e f l e c t i o n not
f r e c e n t land use b u t land use over a long period of time.
However
egetation types conditioned a s they a r e by c l i m a t i c and edaphic
o r s could not have changed g r e a t l y during recent times.
They may
o s t o r gained c e r t a i n of t h e components with minor o s c i l l a t i o n s of
a t e but t h i s would not have a f f e c t e d t h e i r permanancy o r existence.
e r man a s an ecological f a c t o r has had f a r reaching e f f e c t s .
The
opment associated with the p a s t o r a l i n d u s t r i e s has r e s u l t e d i n the
uction of l a r g e areas of n a t u r a l vegetation.
Acacia shrub, tussock grasslands, hummock grasslands, forblands and EucaZyptus
The major vegetation types found i n the area a r e
ands f r i n g i n g the major r i v e r s and channels.
Specialised p l a n t
c i a t i o n s i n h a b i t swamps and mobile c r e s t s of sand dunes and other
a t s o£ limited areas.
A s the dominant species change with h a b i t a t ,
pearance of t h e associations a l t e r s accordingly but there a r e
a1 f e a t u r e s exhibited by the vegetation regardless of the dominant
e s o r s t r u c t u r a l formation.
Usually t h e p l a n t s form s t r u c t u r a l l y simple associations, low i n
t h height and p r o j e c t i v e f o l i a g e cover.
p t i n favoured s i t u a t i o n s .
The l a t t e r r a r e l y exceeds 30%
Although t h e associations a r e s t r u c t u r a l l y
l e they commonly e x h i b i t d i s t i n c t layering.
The components of these
ous stratum a r e not always constantly associated w i t h one anothe;.
s layered e f f e c t has been observed i n other a r i d areas i n Australia by
ious workers including Everist (1949),Perry and Lazarides (1962) and
d and Webb (1974).
Another f e a t u r e of these assocations i s t h a t
quently only a few species contribute s i g n i f i c a n t l y t o t h e biomass of
ns dominated by various species of EucaZyptus a r e not
'
approximately 5% of t h e area.
twelve (12) associations i s recognized ( ~ p p e n d i x11).
ccur mainly on grey c l a y s , a l l u v i a l s o i l s and t e x t u r e
o i l s associated with a l l u v i a l p l a i n s and braided channels.
They
eveloped along the Paroo and Bulloo Rivers and associated creeks
i n varying degrees of complexity along a l l r i v e r s and major creeks
Less extensive areas a r e found on t e x t u r e c o n t r a s t s o i l s and
r e e red e a r t h s i n t h e e a s t associated with Acacia aneura
Limited areas of various Eucazyptus spp. predominant
e found on pediments and eroded lower slopes of t h e dissected
e e a s t of t h e region.
Other EucaZyptus spp.
ined t o specialized h a b i t a t s such a s i s o l a t e d dunes
r i v e r t e r r a c e s associated with a l l u v i a l p l a i n s .
S t r u c t u r a l l y the associations range from low open woodland t o open
Various s t r a t a may be conspicuous and these range from a pronounced
l a y e r through shrubby l a y e r s t o t a l l understorey.
There i s a
cy f o r a decrease i n physiognomic complexity of t h e association with
sing distance from t h e main channel and increasing a r i d i t y .
~pproximately
F l o r i s t i c a l l y these associations a r e r e l a t i v e l y r i c h .
t h e t o t a l species recorded occur i n these associations.
Major f a m i l i e s
buting t o t h e f l o r a include Poaceae, Asteraceae, Leguminosae f i n the
n s e ) , Chenopodiaceae, Myrtaceae and Cyperaceae.
Genera which Occur
y a r e EucaZyptus, Eragrostis, ScZeroZaena, Acacia, Cypems,
Species d i v e r s i t y of t h e various associations
and EremophiZa.
eases with increasing a r i d i t y .
Various species of EucaZyptus predominate depending on l o c a l
ation i n habitat.
The most extensive association i s the EucaZyptus
ZduZensis, E. microtheca open woodland associated with t h e a l l u v i a l
ns of a l l major r i v e r s .
E. microtheca low open woodland and
chrophZoia woodland a l s o contribute s i g n i f i c a n t l y t o the vegetation
e region.
E. p~puzneapredominant associations, found mainly i n the
t with an a f f i n i t y f o r transported d e t r i t u s
and dissected r e s i d u a l s
t h e l a t e r i t e and s i l c r e t e land surface, a r e of a r e a l importance.
aining associations are limited i n extent.
The
ecotones a r e frequently noticeable between these
d adjacent associations.
associations occur throughout the area and occupy
0% of t h e area.
t a l of e i g h t ( 8 ) associations were erected and described
They a r e developed i n two d i f f e r e n t s i t u a t i o n s , one
h t h e a l l u v i a and t h e other on mantled pediments and
t s of t h e d i s s e c t e d r e s i d u a l s .
t r u c t u r a l l y , t h e associations range from woodland t o sparse
n shrubland.
The a l l u v i a l s o i l s , cracking c l a y s , and t e x t u r e
s o i l s support woodlands t o t a l l open shrublands.
Various
t r a t a may occur and contribute s i g n i f i c a n t l y t o t h e biomass.
If
s s o c i a t i o n has been disturbed then dense shrubby layersmay be
loped.
Sparse, t a l l open shrubland t o t a l l open shrublands occur
acking c l a y s , and t e x t u r e c o n t r a s t s o i l s associated with the mantled
ments and scarp r e t r e a t s of t h e dissected residuals.
The number of species recorded from these associations i s about
.5% of t h e t o t a l recorded f o r the area.
Families which are well
resented by r e l a t i v e l y l a r g e numbers of s p e c i e s a r e Poaceae,
enopodiaceae, Leguminosae f i n the broad s e n s e ) , Myoporaceae, Cyperaceae,
vaceae and Amaranthaceae.
Genera. contributing s i g n i f i c a n t l y t o t h e
r a of these associations include Sclerolaena, Eremophila, Cyperus,
grostis, AtdpZex and Cassia.
Overall Chenopodiaceae makes a major
n t r i b u t i o n t o t h e f l o r a not only i n the number of d i f f e r e n t species
esent but the abundance i n which these species occur.
Blake (1938) s t a t e d t h a t A. cmnbagei enjoys t h e widest range of
a b i t a t s of a l l t r e e s and shrubs i n western Queensland b u t observations
uggest t h a t A. aneura had adapted t o a wider range of h a b i t a t s .
. cambagei
woodland and A. cambagei t a l l shrubland would be the most
xtensively developed of t h e associations recognized.
A. cambagei may form complexes with Eucalyptus spp. i n a l l u v i a l
s i t u a t i o n s and with A. aneura on mantled pediments.
They frequently
f r i n g e AstrebZa spp. tussock grassland on t h e undulating downs and i n
some s i t u a t i o n s give t h e impression of invading t h e downs.
This was
ophyZZa communities a r e not extensive and
these associations, A. karpopkyZla predominant
ed under t h i s grouping.
A. harpophyZZa associations range from low open
i s t i c a l l y these associations a r e r e l a t i v e l y poor compared
roupings i n t h e area.
c i a t i o n s a r e found throughout the area on f l a t t o
Totally t h e associations occupy approximately 30%
teen (15) f l o r i s t i c associations were delineated and described
A. aneura predominant associations occurs on a wide
11).
landscapes from dissected r e s i d u a l s through transported d e t r i t u s
ssected r e s i d u a l s of t h e l a t e r i t e and s i l c r e t e land surface t o sand
overlying both a l l u v i a and t e r t i a r y land surface and f i n a l l y dune-
.
S o i l s supporting these associations vary g r e a t l y from s i l i c e o u s
through red e a r t h s t o deep cracking, red clays.
However these
i a t i o n s reach t h e i r b e s t expression i n t h e e a s t of t h e region on
loamy red earths.
S t r u c t u r a l l y these associations range from low woodland t o sparse
1 open shrubland.
The most frequently occurring s t r u c t u r a l formations
t a l l shrubland and t a l l open shrubland.
A. aneura a l s o forms
e r s t o r e y s t r a t a i n layered woodlands o r emergent l a y e r s i n hummock o r
sock grasslands.
The physiognomic complexity of mulga associations
creases along a gradient from a more favourable environment i n t h e e a s t
the region t o t h e harsh environment i n the west.
A. aneura
s o c i a t i o n s a l s o e x h i b i t a v i s u a l l y recognisable p a t t e r n r e f e r r e d t o a s
grove p a t t e r n .
i d areas.
The groving appears t o be b e t t e r developed i n the more
Groving i s exhibited by some A. aneura associations i n the
s t b u t it i s very d i f f u s e and d i f f i c u l t t o recognize without tlie a i d of
r i a l photographs.
Other p a t t e r n s probably e x i s t i n A. enema
s o c i a t i o n s i n view 'of Anderson's findings (1970) but these p a t t e r n s a r e
t r e a d i l y v i s i b l e and s t a t i s t i c a l methods a r e needed t o recognize them.
I shrubland and A. aneura t a l l open shrubland.
A. aneura
e complexity of both s t r u c t u r a l formation and f l o r i s t i c s
A t t h e o t h e r extremity i s sparse A. aneura t a l l open
. terminaZis codominant i n places.
It may be considered
e x h i b i t varyin; degrees of a f f i
cia aneura + Acacia spp. + EwaZyptus terminalis low open woodland
ughspecies composition and a tendency t o favour s i m i l a r h a b i t a t s .
1s a r e red earthy sands t o red s i l i c e o u s sands l e s s frequeritly yellow
s t r u c t u r a l l y these associations vary g r e a t l y and include low
land, t a l l open shrubland, sparse t a l l open shrubland, wooded
a d s and forblands.
lori is tic ally t h e composition of these associations is v a r i a b l e .
e r of species recorded from these associations is r e l a t i v e l y high
ng approximately 30% of a l l species l i s t e d f o r t h e area.
An
f e a t u r e i s the 'high percentage of ephemerals recorded f o r
ciations.
Families with l a r g e representation include Poaceae,
ceae, Leguminosae, Asteraceae, Myoporaceae and Amaranthaceae.
r a p r e s e n t a r e ScZeroZaena, Acacia, EremophiZa, Eragrostis,
PtiZotus.
The major associations contributing t o t h e vegetation of t h i s
aneum + &acia spp. + EucaZyptus
nazis low open woodland and A. caZcicoZa + A. anetcra t a l l open shrubmng are AtaZaya hemigZauca
and.
+ Acacia
The former a s s o c i a t i o n i s r a t h e r diverse and undoubtedly t h i s could
have been subdivided i n t o more homogenous u n i t s with more d e t a i l e d study.
Acacia petraea, A. catenuZata, A. stowardii predominant associations.
These associations a r e found throughout t h e a r e a and a r e
r e s t r i c t e d ' t o dissected r e s i d u a l s , t h e scarps and adjacent f l a t tops.
These associations occupy approximately 1 2 % of the area.
Six (6) associations were erected and described (Appendix 11).
Delineation of these associations a r e d i f f i c u l t i n places.
There i s
a high c o r r e l a t i o n between p o s i t i o n i n the landscape and f l o r i s t i c
association.
A s the f a c e t s of the landscape grade i n t o each other s o
do the a f f i l i a t e d f l o r i s t i c associations.
earths t o lithosols.
S o i l s vary from shallow, red
Exposed p a r e n t rock i s common.
S t r u c t u r a l l y these associations range from low open shrubland
t o low woodland.
A. petraea and A. catenuzata form low woodlands t o
low open woodlands a t the e a s t e r n limits of t h e area and i n i s o l a t e d
pockets on the Grey Range.
Similar t o other vegetation of t h e region,
these associations do not usually e x h i b i t any physiognomic complexity.
The woodlands a r e associated more frequently with the jump-up o r dropo f f s and the t a l l open shrubland o r low open shrubland occur on the f l a t
tops adjacent t o the drop-offs o r the lower slopes of t h e mesas and
"uttes.
I n places t h e f l a t tops and undulating p l a i n s may support low
open woodland.
P l a t e 12.
AtripZex n m z a r i a low open shrubland ( F l o r i s t i c
a s s o c i a t i o n 5 1 ) , edge of f l o o d p l a i n of Bulloo
R i v e r , Bulloo Downs.
P l a t e 13.
Muehlenbeckia cunninghamii low open shrubland
( F l o r i s t i c a s s o c i a t i o n 5 0 ) , floodplain of t h e
Cooper Creek.
racking brown and grey clays.
s t r u c t u r a l l y , these associations range from low open shrubland t o
en shrubland and r a r e l y shrubland.
Frequently these associations
lexes with EucaZyptus microtheca low open woodland and various
These associations a r e f l o r i s t i c a l l y v a r i a b l e , but usually low
diversity.
do occur.
Under c e r t a i n conditions a l a r g e number of
I t i s these species, which appear i n profusion a f t e r
e s p e c i a l l y i f t h e a r e a has been submerged f o r a period of time,
i d e s the bulk of fodder most important f o r c a t t l e f a t t e n i n g .
ch occur i n abundance following flooding include EchinochZoa
Craspedia pZeiocephaZa, T~igoneZZasuavissima and Senecio Zautus.
i t h l a r g e representation includes Poaceae, Chenopodiaceae,
and Leguminosae ( i n the broad s e n s e ) .
Genera which a r e
ed by l a r g e numbers a r e ScZeroZaena, Eragrostis and AtripZex.
Of the f l o r i s t i c associations, those which a r e of a r e a l s i g n i f i c nclude Chenopodiwn auricomum low open shrubland, Chenopodiwn auriconm,
nbeckia c u n n i n g h i i low open shrubland, M. cunninghamii low open
and and Eragrostis austraZasica open tussock grassland.
i
I n the "channel country" t h e various p l a n t associations grade i n t o
another.
Delineation of t h e various associations i s d i f f i c u l t and it
onvenient t o consider it a s a complex.
These associations occur on dunefields and adjacent f l a t p l a i n s
s t and occupy approximately 10%of t h e t o t a l area.
A t o t a l of two (2) f l o r i s t i c associations were delineated and
(Appendix 111.
Tr-iodia basedmii predominant associations a r e
e s t r i c t e d t o t h e more s t a b l e slopes and inter-dune f l a t s and a r e
only found on mobile c r e s t s .
The mobile c r e s t s may support
a paradoxa open hununock grassland.
These two associations have
uped togethel; because of t h e common broad h a b i t a t and s i m i l a r i t y
i a t e d species.
S o i l s vary from r e d , s i l i c e o u s sands t o red,
t u r a l l y , t h e associations range from open hummock grassland
land.
Scattered low shrubs o r low t r e e s may emerge and
r dense stand approaching a t a l l open shrubland o r low
t i c a l l y the a s s o c i a t i o n s a r e v a r i a b l e , t h e species present
a1 environmental conditions.
Considering only t h e ground
asedowii forms almost pure stands i n t h e undisturbed s t a t e .
, by
grazing o r f i r e , species d i v e r s i t y increases.
This
species d i v e r s i t y decreasing a s an a s s o c i a t i o n approaches
pears t o be exhibited by s e v e r a l p l a n t associations i n t h i s
The l a r g e number of composites and t h e l a r g e proportion of
i n t e r e s t i n g but not an unexpected f e a t u r e of the f l o r a .
In
Id be unusual, i f a l a r g e percentage of t h e species present were
,particularly
llable.
i n a region where p r e c i p i t a t i o n i s s o v a r i a b l e
Families with l a r g e representation include Asteraceae,
podiaceae, Poaceae, Leguminosae ( i n t h e broad s e n s e ) , Rmaranthaceae
oporaceae.
Genera which a r e represented by l a r g e numbers a r e
Zaem, Acacia, Eragrostis, EremophiZa, Cassia, CaZotis and PtiZotus.
.
ZygochZoa paradoxa open humock grassland is f l o r i s t i c a l l y very
I n good seasons t h i s association approaches a forbland and species
r s i t y increases with ephemerals occupying the bare a r e a s between the
s of 2. paradom.
I n Triodin basedowii predominant associations t h e r e a r e undoubt-
y many groups of p l a n t s which would be considered "plant c o m u n i t i e s "
er s t i l l " h a b i t a t types" i n the sense of Wiedemann (1971). To
t e these, d e t a i l e d study would have been necessary.
One objective
i s p r o j e c t was a b a s i c inventory of the vegetation f o r land use and it
onsidered unnecessary t o subdivide t h e .'2
basedowii p r
These associations occur i n the west on f l a t t o undulating downs.
i t e d areas a r e dev'eloped on the a l l u v i a l p l a i n s .
These associations
cupy approximately 8% of t h e area.
A t o t a l of t h r e e ( 3 ) f l o r i s t i c associations were erected and
escribed (Appendix 11).
S o i l s a r e predominantly deep, stony; red and
rown c l a y s and shallow t o moderately deep, stony d e s e r t loams.