Flora and vegetation of the Eastern Goldfields Ranges: Part Mt Manning Range



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35

Flora and vegetation of the Eastern Goldfields Ranges:

Part 6. Mt Manning Range

N Gibson


Science Division, Department of Conservation and Land Management, Wildlife Research Centre,

PO Box 51 Wanneroo, WA 6065

 neilg@calm.wa.gov.au

(Manuscript received July 2003; accepted June 2004)

Abstract

This study of the flora and plant communities of the Mt Manning greenstone belt (some 100 km

N of Koolyanobbing) recorded a total flora of 238 taxa, of which 234 were native and four were

introduced. The species list is poorer than reported for previously studied ranges and shows a

compositional shift consistent with the more semi-arid nature of the climate. The most common

life-forms were shrubs 50% and annual herbs 23.5%. No taxa were found to be endemic to the

greenstone belt. Seven community types were defined from 54 quadrats established along the

range system. These communities types were strongly correlated with edaphic factors, and are

compositionally distinct from those of nearby ranges to the south. The vegetation of the Mt

Manning Range, like that of the Helena & Aurora Range to the south and Die Hardy Range to the

west, is very poorly conserved. The results of the current survey support previous

recommendations for the inclusion of the Mt Manning greenstone belt into the Nature Reserve.



Keywords

: flora, vegetation, Goldfields, Mt Manning Range, Western Australia, greenstone



Introduction

The Mt Manning greenstone belt extends some 30 km

from the Mt Manning Range north to the Evanston-

Menzies Road, about 100 km north of Koolyanobbing. It

consists of ca a 1 km-thick sequence of variously

metamorphosed basalt overlain by chert and banded

ironstone, which in turn is overlain by high-Mg basalt

and minor gabbro separated by banded ironstone

(Greenfield 2001). These belts are a common landform of

the Eastern Goldfields and incorporate most of the

mineralization. As a consequence, they have been heavily

exploited for mineral exploration and mining for over

100 years. Despite this, a detailed knowledge of the flora

and vegetation of individual ranges is still lacking,

although broad scale structural vegetation mapping

(Beard 1972) and regional surveys (Keighery et al.1995)

are available.

This paper continues a this series of papers that report

on detailed floristic studies on some of these ranges, to

address this deficiency (Gibson et al. 1997; Gibson &

Lyons 1998a,b; Gibson & Lyons 2001a,b). The Mt

Manning greenstone belt is the most arid system yet

studied, and provides contrast to the biogeographic

patterns reported from other range systems.



Study Locality

The study area lies ca 100 km north of Koolyanobbing

and covers all of the Mt Manning greenstone belt (Fig 1;

Greenfield 2001). The belt runs north-south and is ca 6

km wide but quickly narrows to less than 2 km. The

geology of the study area has been mapped and

described in detail in the Lake Giles and Bungalbin 1:

100000 sheets (Greenfield 2001, Chen & Wyche 2001)

following earlier regional studies of Walker & Blight

(1983). The lenticular greenstone belts of this region are

believed to be 3000 My old and to have subsequently

undergone multi-staged metamorphism that peaked with

the major granitiod intrusion between 2710 and 2670 My

ago. These ancient rocks have weathered into gently

undulating plains and broad valleys covered by Tertiary

soils (< 65 My old). These soils may develop in situ from

the weathering of laterite duricrusts, or represent

depositional soils derived from the ancient rocks or the

Tertiary laterization (Greenfield 2001). The net result is a

very subdued landscape except for the highly resistant

banded ironstones which form a series of abrupt rocky

outcrops.

The climate of the region is warm dry mediterranean

with warm winters and hot summers. Mean annual

rainfall at Diemals Station (ca 45 km NW of the range) is

275 mm, with moderate seasonal variation over the 23

years of record (1970-1994; decile 1, 157 mm; decile 9, 436

mm) Most rain falls in winter generally associated with

frontal activity from April through August. Summer falls

are highly erratic and result from thunderstorms.

Heaviest falls (to 127 mm) are associated with rain

bearing depressions forming from tropical depressions

(Milewski & Hall 1995; Bureau of Meteorology 2004). The

temperature data from Diemals show mean maximum

temperatures is highest in January (36 °C) with

November through March all recording mean annual

temperatures above 30 °C. Lowest mean minimum

temperatures of 4 °C are recorded in July. The highest

daily maximum temperature recorded was 46.5 °C with

the lowest being –4.6 °C. On average there are 15.9 days

a year over 40 °C and 67.2 days above 35 °C, with 11.1

days per year with the minimum below freezing (Bureau

of Meteorology 2004).

The Mt Manning Range lies in the South Western

Journal of the Royal Society of Western Australia, 87:35–47, 2004

© Royal Society of Western Australia 2004



36

Journal of the Royal Society of Western Australia, 87(2), June 2004



Figure 1.

 Location of the study area and distribution the 54 quadrats along the Mt Manning Range (solid triangles). Most of the uplands

(and the quadrats sampled) fall in an enclave of Unallocated Crown Land within the Mt Manning Nature Reserve.

Interzone close to the border with the Murchison

botanical region (Beard 1990). The Interzone is generally

dominated by eucalypt woodlands and shrublands on

yellow sandplains and it marks the transition in

vegetation from the species-rich south west to the more

arid communities of the desert regions. The Murchison

region is dominated by mulga (Acacia aneura) low

woodlands.

Beard (1972) described the major structural formations

of the Jackson 1:250 000 sheet which lies immediately

south of the Mt Manning Range. He consideres the Die

Hardy vegetation system on the northern edge of that

map sheet to be similar to that occurring on the banded

ironstones of Mt Jackson and Koolyanobbing Range, but

slightly different due to its lower rainfall. Brachychiton



gregorii and Dryandra arborea are occasional trees on the

range crest, with the northern slopes dominated by open

scrubs of Acacia aneura, A. linophylla, A. acuminata, A.

tetragonophylla and Dodonaea sp. The southern slopes

support dense thickets of Allocasuarina acutivalvis and A.



campestris with some acacias and eucalypts.

Keighery et al. (1995) ascribe the vegetation of the Mt

Manning Range to this vegetation system. They identify

30 major structural vegetation units as occurring along

the range. The ridges of the range support five structural

units; Acacia aneura tall shrubland, Eucalyptus ebbanoensis

mallee,  Acacia quadrimarginea tall shrubland, Dryandra

arborea tall shrubland, and Allocasuarina acutivalvis tall

shrubland. The E. ebbanoensis mallee is a stunted version

of the vegetation of the lower slopes. The two Acacia

shrublands have similar composition but differing

dominance and the Dryandra shrubland occupies lateritic

patches on the ridge crests. Pure Acacia aneura low

woodlands occur on lower slopes on deep colluvial soils

while the valleys are dominated by Eucalyptus salubris

and/or E. salmonophloia woodland or by Casuarina pauper

(syn C. cristata) low woodland around the base of the Mt

Manning Range and on small rises of greenstone on the

plain. The surrounding sandplain is dominated by



Eucalyptus formanii over Plectrachne rigidissima.

The aim of the present work was to undertake a

detailed floristic survey of the Mt Manning greenstone

belt. This involved the compilation of a detailed flora list,

and the description of the vegetation patterning of the

area based on a series of permanently located quadrats.



Methods

Fifty-four 20 m x 20 m quadrats were established on

Mt Manning Range, side slopes and outwash plains

surrounding the range (Fig 1). These quadrats attempted

to cover the major geographical, geomorphological and

floristic variation found in the study area. Care was taken

to locate quadrats in the least disturbed vegetation


37

available in the area being sampled. All vascular plants

were recorded within each quadrat. Quadrats were

permanently marked with four steel fence droppers and

their positions determined using a GPS unit. Twenty-four

soil samples from the upper 10 cm were collected from

each quadrat. These were bulked and analyzed for

electrical conductivity, pH, total N, total P, available K

(McArthur 1991).

Quadrats were sampled in early November 1995. Data

on topographical position, slope, aspect, percentage litter,

percentage bare ground, percentage surface rock

(bedrock and surficial deposits) and vegetation structure

were collected from each quadrat. Topographical position

was scored on a subjective six point scale; ridge tops = 1,

upper slopes = 2, midslopes = 3, lower slopes = 4, valley

flats =5, small rise in valley =6. Slope was scored on a

one to three scale from flat to medium, to steep. Aspect

was recorded as one of 16 cardinal directions. Altitude

was taken from 1:100000 series topographical map to

nearest 10 m. Vegetation structure was recorded using

Muir’s (1977) classification.

Quadrats were classified according to similarities in

species composition. In these analyses only perennial

species were used to facilitate comparisons with

classifications from other ranges (Gibson et al. 1997;

Gibson & Lyons 1998a,b; Gibson & Lyons 2001a,b). The

quadrat and species classifications undertaken used the

Czekanowski similarity coefficient and “unweighted

pair-group mean average” fusion method (UPGMA

module in PATN, Belbin 1995, beta value -0.1, Sneath &

Sokal, 1973). Semi-strong hybrid (SSH in PATN)

ordination of the quadrat data was undertaken to show

spatial relationships between quadrat groups (here

referred to as community types) and to elucidate possible

environmental correlates with the classification (Belbin

1991). Methods of Dufrene & Legendre (1997) were used

to determine best indicator taxa for each group (from PC-

ORD v 4.24, McCune & Mefford 1999).

Climate estimates (mean annual temperature, annual

temperature range, mean annual rainfall, rainfall

coefficient of variation) were obtained from BIOCLIM

(Busby 1986), a prediction system that uses mathematical

surfaces fitted to long term climate data. Relationships

among and between physical site parameters and climate

estimates were examined using Spearman rank

correlation coefficient. To reduce the probability of type I

errors given the number of intercorrelations, significance

differences were reported at a level of P<0.01. Vectors for

the physical site parameters, latitude, altitude and

climatic estimates were fitted to the ordination along axes

of highest correlation using the principal axis correlation

routine (also known as rotational correlation analysis) in

the PATN package (Belbin 1995). Statistical significance

of these vectors was determined using random

permutations of the values of the variable among sites

(Faith & Norris 1989). Statistical relationships between

quadrat groups for physical site parameters and climate

estimates were tested using Kruskal-Wallis non-

parametric analysis of variance (Siegel 1956).

Nomenclature generally follows Paczkowska &

Chapman (2000). Voucher specimens have been be

lodged in the Western Australian Herbarium. Introduced

taxa are indicated by a “*”.



Results

Flora

A total of 238 taxa (species, subspecies, varieties) were

recorded from the Mt Manning greenstone belt

(Appendix 1). The flora list was compiled from taxa

found in the 54 quadrats or the adjacent area and from

collections of the Western Australian Herbarium. Of

these 238 taxa, 234 are native and four are weeds.

Sampling was undertaken in the first week of November

1995 and although good rains had fallen in winter and

spring of 1995, the annuals and geophytes were largely

finished and further additions could be expected to the

flora list. The best represented families were the

Asteraceae (37 native taxa and 2 introduced taxa),

Myrtaceae (32 taxa), Chenopodiaceae (13 taxa), Poaceae

(12 native taxa and 2 introduced taxa) Myoporaceae (11

taxa), and Mimosaceae (10 taxa). This pattern is typical of

the flora in changeover zone between the of the South

Western Botanical Province and the Eremaean (Gibson et



al. 2000). The most common genera were Eucalyptus (17

taxa),  Eremophila (11 taxa) and Acacia (10 taxa). Most

common life-forms were shrubs 50%, annual herb 23.5%,

perennial herbs 5.5%, mallee 5.0%, trees 4.6% and

perennial grasses 4.2%. These six life-forms accounted for

over 92% of taxa recorded.

Six taxa of conservation significance (Atkins 2001)

were recorded (Calytrix creswellii, Daviesia purpurascens,



Eremophila sp (GJ Keighery 4372), Eucalyptus formanii,

Grevillea erectiloba, and Grevillea georgeana). Of these

Eremophila sp (GJ Keighery 4372) and Calytrix creswellii

are the most poorly known, being represented by only 5

and 15 collections respectively in the Western Australian

Herbarium. All six taxa with the exception of Daviesia



purpurascens have a geographic range of ca 200 km and

can be considered regional endemics of the greenstone

and banded ironstone ranges (Eremophila sp (GJ Keighery

4372),  Grevillea erectiloba, Grevillea georgeana) or the

surrounding sandplain (Calytrix creswelliiEucalyptus

formanii), although the latter two taxa do also occur on

the lower slopes or outwash plains of the Mt Manning

Range.

Vegetation

Only plant material that could be identified to species

or subspecies level was included in the analysis (ca 95%

of records). In the 54 quadrats established on the Mt

Manning Range, 197 taxa were recorded of which 142

were perennial. Fifty-five perennials occurred at only one

quadrat. Preliminary analyses showed these singletons

had no effect on the community classification and were

therefore not considered further. As a result the final data

set consisted of 87 perennial taxa in 54 quadrats. Species

richness ranged from five to 23 taxa per quadrat, with

individual taxa occurring in between two and 38 of the

54 quadrats.

The 54 quadrats were divided into two primary

groups, the first group (types 1-5) containing quadrats

with skeletal soils over banded ironstone or weathered

yellow sand on banded ironstone or laterite, the second

group (types 6 & 7) containing quadrats on greenstone or

colluvial soils (Fig 2).

• Community type 1 were species poor quadrats that

Gibson: Flora and vegetation of Mt Manning Range


38

Journal of the Royal Society of Western Australia, 87(2), June 2004

generally occurred on massive banded ironstone

near the crest of the range. Species richness was

low (mean 10.5 taxa plot

-1

) with only some taxa in



species groups A and F (Appendix 2) being

consistently represented. Best indicator species for

this group were the rock fern (Cheilanthes

austrotenuifolia), Calycopeplus paucifolius, Austrostipa

trichophylla,  and  Eremophila clarkei. Other constant

species to this group included the perennial grass



Amphipogon strictus. One quadrat in this group

occurred on massive greenstone on a small rise

near the base of the range.

• Community type 2 occurs on the lower flanks of

the ranges on somewhat deeper soils. This

community type is generally dominated or co-

dominated by Eucalyptus ebbanoensis, Acacia

ramulosa, A. aneura, A. quadrimarginea and/or at the

foot of the range by Callitris glaucophylla. Indicator

taxa include Callitris glaucophylla, Prostanthera

althoferi subsp althoferi. Species groups G and H are

largely restricted to this community type but at

low constancy levels (Appendix 2). Species group

A is also well represented, as is Eremophila latrobei

subsp  latrobei. Average species richness was 12.7

taxa plot

-1

.

• Around the base of the range and on some upland



units, a characteristic yellow sand unit develops

over laterite. Community type 3 occurs on this unit

and is characterized by high constancy of taxa in

species group F, half of which are indicator

species. Typical co-dominant indicators include,

Allocasuarina acutivalvis, Melaleuca nematophylla and

Acacia quadrimarginea. Typical shrub indicators

include Baeckea elderiana, Hibbertia rostellata,



Grevillea obliquistigma, Phebalium canaliculatum,

Grevillea paradoxa and G. georgeana (Appendix 2).

Average species richness is high at 14.5 taxa plot

-1

.

This community is most common around the base



of the range but does occur where ever the laterite

sheet remains.

• Community type 4 occurs on eroding breakaways

which are dominated by Eucalyptus capillosa subsp



capillosa. This landform is very restricted at the Mt

Manning Range; it is more common on the banded

ironstones of the Helena and Aurora Range and

the Yendilberin Hills to the south (Gibson et al.

1997; Gibson & Lyons 2001b).

• Community type 5 occurred at a single quadrat on

sandy alluvial soils in a narrow drainage line at

the base of the range. Species richness was low

with only eight perennial species being recorded,

three of which were only recorded at this quadrat.

This quadrat was dominated by Eucalyptus

formanii; it may represent either a depauperate

example of community type 2 or be more

representative of the surrounding sandplain that

were not sampled in this study (Keighery et al.

1995).

• Community types 6 and 7 appear to represent



community types on the more fertile soils lower in

the landscape. Taxa in species group A are most

faithful to these two communities.

• Community type 6 are eucalypt mallees and

woodlands which are found on the lower slopes,

valley and small rises in the valleys. These

quadrats are generally dominated by Eucalyptus

griffithsii and/or E. ebbanoensis or occasionally by

Casuarina pauper. This community differs from

community type 7 by the general lack of

chenopods (Appendix 2). Best indicator taxa of this

community included Eucalyptus griffithsii, Olearia



muelleri, Acacia tetragonophylla, Ptilotus obovatus and

Acacia erinacea. Average species richness was high

at 16.9 taxa plot

-1

.

• The final community type (type 7) is the chenopod



rich eucalypt woodlands of the valleys and small

rises. Common dominants include Eucalyptus



salubris and occasionally Casuarina pauper. Indicator

taxa were largely chenopods (Appendix 2).

Average species richness was again high at 14.5

taxa plot

-1

.

Physical Correlates



Soil parameters showed high levels of intercorrelation,

as did the site parameters and the climate parameters.

Total P was not correlated with any other soil parameter

except for total N, while total N was not correlated with

pH (Table 1). All other soil parameters were

intercorrelated. Of the site parameters only topographic

position showed no intercorrelation while slope, aspect,

percentage rock, percentage litter and percentage bare

ground were all highly intercorrelated. Altitude, latitude

and the four climate parameters also showed a significant

degree of intercorrelation. A much lower degree of

intercorrelation was evident between these three

different types (soil, site and climate) of parameters

(Table 1).



Figure 2.

 Dendrogram of 7 group level classification of 54

quadrats established along the Mt Manning greenstone belt.

  1  2  3  4  5  6  7

Community type

1.31 _

1.21 _

1.11 _

1.02 _

0.92 _

0.82 _

 Information 

statistic


39

Table 1

Matrix of Spearman rank correlation coefficients between site physical parameters and climate estimates. Only correlation signi

ficant at P < 0.01 shown. (Climate parameter codes: Tann, mean

annual temperature; Tar, annual temperature range; Rann, mean annual rainfall; Rcv, rainfall coefficient of variation.)



EC

p

H

N

P

K

Position

Slope

Aspect

% rock



litter



bare

altitude

latitude

Tann

Tar



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