Download Australian Biodiversity Under Threat

Robert Boden
Consultant to
Science, Technology, Environment and Resources Group
29 May 1995
Parliamentary
Research Service
Research Paper No, 261994/95
Australian Biodiversity Under Threat
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CONTENTS
Major Issues
_
1
_
Introduction
3
What is it about Australia's environment which encourages biodiversity?
3
Isolation
Size
Rainfall
Soils
Fire
Summary
3
4
4
4
4
5
:
Australian biodiversity
Species diversity
Vegetation and habitat diversity
5
5
6
"
9
Importance of biodiversity
9
New uses for plant biodivenity
Phannaceutical products
10
10
10
Cutflowers
Forest tree seed
Land use and vegetation change
Past and present land use patterns
Vegetation change
11
Threats to divenity
17
17
18
11
12
Species lost and under threat
Loss of habitat.
Feral animals and weeds
Erosion and soi Idegradation
Fire
Dieback disease
lIIegal trapping
Conserving biodiversity
"
"
20
21
21
21
22
22
Plant communities
22
Research and survey
23
International conservation agreements
Parks and reserves system
24
24
Other public lands
Private and leasehold land
25
26
References
29
Appendix
32
TABLES
1.
Proportions of endemics at the species level for each major species group
2.
Forest cover in world regions
12
3.
Decline in forest cover 1788-1980 for each Australian State and
mainland Territory
13
Decline in woodland cover 1788-1980 for each Australian State and mainland
Territory
14
5.
Changes in vegetative cover between 1788 and 1980
17
6.
Numbers of endangered. vulnerable and presumed extinct species in Schedule 1
ofthe Endangered Species Protection Act /992 (at 30 April 1993)
17
4.
6
FIGURES
I.
Major vegetation types in Australia
7
2.
Distribution of threatened (endangered and vulnerable plant species)
16
3.
The distribution of the koala
19
Australian Biodiversity Under Threat
I
Major Issues
The tenn biodiversity, or biological diversity, has recently emerged from the scientific literature
into everyday language. The reason for this lies in an awakening to the fundamental importance
of biodiversity to Australia's wellbeing and the recognition of increasing threats to it.
Plants and animals and their environments are major factors in attracting international tourists
with over 75 per cent identifying natural scenery and wildlife as key elements in their decision to
come to Australia. In addition, it has been estimated that at least 10 million Australians visit
natural environments each year and over four million visit major zoological gardens. A
household survey carried out by the Australian Bureau of Statistics in 1993-94 revealed that 42.3
per cent of the Australian population over the age of 18 years visited at least one botanic gardens
in the previous year.
This paper describes the geographical characteristics which have resulted in Australia being
recognised as one of about a dozen world centres of megadiversity which, together, account for
60-70 per cent of the world's biodiversity. The extent of Australia's biodiversity is described in
tenns of species and habitats and its economic and cultural importance.
The major changes to biodiversity which have occurred since European settlement and are still
occurring, are identified. By far the most significant change is the continued clearing of native
vegetation with the subsequent loss of species of plants and animals and their habitats.
Compared to other major inhabited countries Australia is the least forested, making vegetation
management one of the most important resource management issues. In about 200 years,
approximately 50 per cent of the forest and 35 per cent of the woodland has been cleared. The
annual rate of clearing is still between 500 000 and 600 000 hectares; an area equivalent to about
five and a half million 'quarter acre' house blocks. Most clearing is occurring in Queensland and
NSW: 450 000 ha and ISO 000 ha respectively in 1990. Areas cleared in Victoria, Tasmania and
South Australia were much less: 6 156 ha, 5 999 ha and 4 4 71 ha respectively.
Since European settlement, 115 species of plants and animals have become extinct and about
300 are classified as endangered and therefore at risk of extinction in the short tenn unless the
existing threats to them are removed or drastically reduced. Leigh and Briggs (1992)
identified grazing and agriculture. mostly following clearing, as responsible for well over 90
per cent of plant extinctions and by far the major present and future threat to plant species
classified as endangered nationally.
Feral animals and weeds have had major impacts on the Australian natural environment. Rabbits,
pigs and faxes are three of more than seventy species of animals which have been introduced and
become established in the wild since European settlement began. At least 2 000 species of
introduced plants are now a pennanent part of the landscape; it is estimated that the total cost of
weeds to the Australian economy is $4 000 million annually.
Road and rail easements are significant areas of public land. In Victoria, for example, roads
occupy about 2.5 per cent of the State. In 1987 there were 870 OOOkm of roads in Australia.
While a large part of the road reserve is dedicated to its primary purpose of carrying traffic, in
rural areas there are often extensive verges which are important habitat for plants and some
Australian Biodiversity Under Throot
Z
animals. The significance of road easements for biodiversity conservation has been recognised
by the Australian Road Research Board which has prepared a draft National Strategy for
Roadside Reserve Management.
There is no doubt that the survival of animals is linked with that of vegetation. But while the
work of Dr Harry Frith and others who followed him clearly indicates that vegetation types have
fonned the most practical basis for detennining conservation reserves in the past, it is unwise to
assume that protecting examples of all of them will necessarily ensure that the diversity of
animals is also adequately conserved.
The major effort to protect biodiversity lies within the parks and reserves system which now
occupies about 6.4 per cent of the country. This system does not adequately cover the range of
habitats, however, and it is becoming increasingly clear that private land and land managed by
other public agencies must playa larger role in conserving Australian biodiversity.
Two ways of achieving this would be stronger controls on clearing remnant native vegetation on
both public and private land and greater incentives for private landowners and leaseholders to
become involved in nature conservation. Justification for public funding of such incentives lies in
recognising that it is the increasing number of urban dwellers which is driving the increasing
demand for food, fibre, water and recreation, most of which comes from rural land. It also lies in
the concept of intergenerational equity, bener known in the Australian ethos as 'wanting to look
after the kids'.
Australian Biodiversity Under Threat
J
Introduction
Biodiversity. greenhouse effect and the southern oscillation index are environmental terms
which now appear daily in the media and are part of the curricula in schools and colleges
around the country.
Biodiversity, or biological diversity as it is sometimes called, is the variety of life on which
the health of our environment depends. It comprises all living plants. animals including
humans, micro-organisms and their habitats. It is the source of foods, fibres, medicines,
building materials and recreational opportunities. Expressed in landscapes and seascapes it
provides inspiration for art, culture and reflection on the meaning of life.
According to the draft National Strategy for the Conservation of Australia (1994),
biodiversity is considered at three levels:
• genetic diversity - the variety of genetic information contained in all of the individual
plants, animals and microorganisms that inhabit the earth. Genetic diversity occurs
within and between the population of organisms that comprise individual species as well
as among species;
• species diversity - the variety of species on the Earth;
• ecosystem diversity • the variety of habitats, biotic communities and ecological
processes.
This paper aims to explain why Australian biodiversity is different and special and why it
is important to conserve it. Clearly, society's demands put pressure on biodiversity. Some
of these threats, how they are being handled now, and how they might be handled better,
are discussed in the paper.
Australians are sometimes apt to blame the inadequate knowledge of the past for the
present state of the environment. We now have much of the knowledge to do better, but do
we have the will to ensure that future generations can be grateful?
What is it about Australia's environment which
encourages biodiversity?
The case for conservation of Australian plants and animals and their habitats is often based on
the argument that Australia is very different from the rest of the world, particularly the
northern hemisphere where the vast majority of people live. But, is this really true and, if so,
why?
Isolation
Australia was originally part of a huge land mass called Gondwanaland consisting of what
is now Antarctica, South America, Africa, India and New Zealand. It broke free about 40
million years ago and began drifting slowly northwards, isolated from other lands by deep
oceans which only a few birds and marine mammals could cross. About ten million years
ago the Australian tectonic plate made contact with that of Asia enabling some invasion
from the north by plants and animals. The first human settlers arrived between 40 000 and
Australian Biodiversity Under Threat
if
60 000 years ago bringing some new species with them. However it is only in the last 200
years that major introductions of new plants and animals have occurred.
This history means the great majority of native plants and animals have evolved m
isolation and are therefore very different from those in other parts of the world.
Size
The large size of the country, about 7.68 million square kIn or 5.7 per cent of the land surface
of the earth, is also important. It is nearly 25 times the area of Great Britain and Ireland and
about equivalent to the United States of America, excluding Alaska. It spans 4 000 kIn east
to west and about 3 700 kIn north to south with 39 percent in the tropics and 61 percent in the
temperate zone.
Rainfall
Australia's geographic position in relation to large ocean masses results in an intensive
atmospheric circulation pattern. Rainfall is not only low but unreliable over much of the
country. varying widely from year to year. Droughts and floods occur so frequently in many
areas they are considered part of the 'normal' climatic pattern. In these areas successful plants
and animals are those adapted to withstand both very wet and very dry periods as well as
average conditions.
The average annual rainfall is only 42 mm compared to 86 rnm for the world's land surfaces
as a whole. This means there are few large rivers and the largest, the Murray River system,
has a very small average run-off. By contrast. run-off from the Mississippi is 40 times, the
Congo 118 times and the Amazon is 148 times greater than the Murray.
Soils
There has been no significant mountain building in the last 100 million years and no recent
volcanic activity (both of which result in new soil formation). Australian soils are therefore
very old. Even though annual rainfall has been low, the long period over which it has acted
on the soils has resulted in severe leaching of nutrients so that naturally occurring nitrates and
phosphates are about half those of some overseas soils.
Prairie soils which enable crops to be grown throughout vast areas of the United States and
Canada are poorly represented in Australia. Generally low phosphorus levels mean that many
native plant species have become so well-adapted to this condition they will not thrive in
phosphate-enriched soils in cultivation. Naturally saline soils are common due to ineffectual
continental drainage.
Fire
Fire was part of the natural environment long before humans arrived and many native plants
developed adaptions related to periodic burning. The natural fire pattern was changed by
Aboriginal people who developed 'fire stick fanning' to drive game out into the open when
Australian Biodiversity Under Threat
5
hunting, to clear paths through the rainforest and to regenerate plant food for themselves and
the animals they used.
It has been demonstrated convincingly that the sedgeland of the west coast of Tasmania is the
result of long use of fire which gradually changed the original rainforest, dominated by the
fire-sensitive beech, Nothofagus cunninghamii, through a phase of mixed eucalypts and
rainforest to scrub and finally heath and sedgeland. With cessation of Aboriginal burning,
rainforest is invading its former habitat in some places.
Different fir~ regimes were used in different parts of the continent. In Amhem Land fire
management was designed to spare fire-sensitive jungle thickets which contain many edible
plants that do not readily regenerate after burning. Wide firebreaks were burnt around these
areas early after the wet season so that later burning in the dry period would not enter the
protected areas.
Aborigines had no capacity or incentive to put fires out and camp fires were left to smoulder
and hunting fires to bum themselves out. Regular burning of tribal territory every three or
four years prevented the accumulation oflitter and disastrous wildfires.
The fire pattern changed again with European settlement. Frequent light burning gave way to
attempts to prevent fire which inevitably led to large accumulations of fuel and devastating
fires. Contemporary Australians are still trying to come to terms with the 'red steer'.
Summary
This combination of long isolation, large size, rainfall, soils and fire prevalence has produced
an array of plants and animals which are different from those in the rest of the world; so
different in fact that considered together over 80 per cent of Australian plants and animals
occur only in this country.
Not only are Australia's plants and animals different from those in the rest of the world but
they are very different from each other. It is these differences which make up biodiversity.
Australian biodiversity
Species diversity
Some idea of biodiversity on a world basis can be gained when it is recognised that there are
more than 9 000 species of birds, 6 300 species of reptiles, 4 000 species of mammals, 4 000
species of amphibians, 21 000 species of fish, 275 000 species of plants and over 1 million
invertebrates and micro-organisms (Australian Academy of Science, 1994).
Some parts of the world are richer than others in numbers of species of plants and animals.
Australia is accepted internationally as one of about a dozen megadiversity countries which
between them account for 60-70 per cent of the world's biodiversity (DASET. 1991).
AuslraJian Biodwersily Under Threat
6
Australia has the planet's second highest number of reptile species (750), is fifth in flowering
plants (22 000), and tenth in amphibians (200) (House of Representatives Standing
Committee on Environment, Recreation and the Arts, 1992).
lbe richness of biodiversity is reflected in the fact that there are more species of ants
inhabiting Black Mountain in Canberra than in the whole of Britain. Furthennore, only
I 600 vascular plants are found in Britain compared to the much smaller area around Sydney
which has over 2000 species (Flannery, 1994).
As indicated above, a distinctive feature of Australia's plants and animals is that many species
are endemic, that is, they are found naturally only in Australia. The proportions of endemics
at the species level for each major group are presented in Table 1 and range from 45 per cent
for birds to almost 100 per cent for insects.
Table J
Proportions of endemics at the species level
for each major species group.
Species Group
Birds
Reptiles
Mammals
Amphibians
Invertebrates
Number of Australian
Species
777
750
282
200
est. 225 000
Flowering Plants
22000
Proportion of endemic
species oAt
45
89
82
93
generally high approaching
100 for some groups
85
Source. Dept. ofthe Environment, Sport and TerritorIes, J994
Vegetation and habitat diversity
In its simplest expression there are seven major land vegetation or habitat types in Australia
although within each there is a myriad of different associations, each with its individual
complement of plants and animals. The major vegetation types are open and closed forest,
woodland, shrubland, scrub (mostly mal lee), heath and herbland or grassland (Figure J)
Although the boundaries between vegetation types are sharp on maps, in reality they are often
gradual and fluctuate over time. For example, the boundary between woodland and open
forest and woodland and grassland may often be hard to detect and certainly the more mobile
animals move freely from one to the other. Birds in particular may rest and nest in the forest
but feed in the open grassland most of the time.
Vegetation types are classified according to height, fonn and density of crown cover
projected onto the ground leading to terms like closed or tall forest, open forest, woodland
and grassy woodland. Within the major vegetation types, descriptive terms indicating the
most obvious species are used. For example, river red gwn forest, yellow box woodland,
brigalow scrub and kangaroo grassland are common terms.
Australian Biodiversity Under Threat
.
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Figure 1: Major Vegetation Types in Australia
Source:
Leigh, J., Boden, R and Briggs. J (198-1) £r/ine' and Endangered Planls of
Australia, Macmillam Australia.
7
Australian Biodiversity Under Threat
8
It is rather more difficult to describe animal habitats in tenns of the species within them. This
is due in part to the fact that botanists have produced vegetation classifications to meet their
own purposes which do not necessarily have much to do with the distribution of vertebrate
fauna. For example, botanists attach less significance than zoologists to habitat features such
as dead or decaying trees with holes or hollows essential for some animals.
There are also many difficulties with the animals themselves. The distribution of amphibians
and reptiles seems to be controlled largely by micro-environment rather than by broad
vegetation associations. Soil hardness, ground vegetation, amount of shade and other factors
may be more important to some small manunals than vegetation structure at a level which can
be seen and mapped.
Migratory species may live in different habitats at different times of the year; for example. it
is estimated that 44 per cent of the 260 species of birds found near Canberra spend part of the
year elsewhere. An example is the pink robin, Petroica rodinogasler, which lives in
rainforest in Tasmania in summer and woodland on the mainland in winter. This pattern
again emphasises the importance of habitat conservation at both ends of migratory paths, and
often in between, for some species to survive. On an international scale this concept forms
the basis for agreements between Australia and some other countries such as China and Japan
for the protection of birds which migrate between them. There are at least 55 species of
wading birds in Australia, 35 of which are regular migrants from Asia. It would be sadly
ironic for the Japanese goverrunent to protect the grasslands where the Japanese snipe.
Gallinago hardwickii, breeds if, when it migrates to Australia in summer. the estuaries and
mud flats it needs have been converted to destination resorts for tourists, many of them also
from Japan.
Where forest, woodland. scrub and grassland tend to merge into one another it is difficult to
assign an animal to one particular vegetation type. Also some species are 'fringe dwellers'
inhabiting the interface between one plant community and another and are favoured by a
mosaic of different types.
Despite these difficulties the late Dr Harry Frith in his· pioneering work Wildlife Conservation
(published in 1973) was able to determine the approximate distribution of most species of
birds and mammals among the different vegetation associations Australia wide. Woodland
was found to support more species than any other vegetation type.
Among the birds 323 species (48 per cent) are able to live in woodlands and to 227 species (34 per cent)
it is the most important habitat; 20 per cent of the bird species are practically confined to it. Among the
mammals the percentages are higher; excluding the bats, 135 species (76 per cent) live in woodlands and
to 227 species (34 per cent) it is the most important habitat; 20 per cent of the bird species are practically
confined to it. Among the mammals the percentages an: higher, excluding the bats, 135 species (76 per
cent) live in woodlands. It is the main habitat of 30 per cent of the mammal species and the great
majority of these live nowhere else (Frith, 1973).
Australian Biodiversity Under Threat
9
There is no doubt that the survival of animals is linked with that of vegetation. But while the
work of Dr Harry Frith and others who followed him clearly indicates that vegetation types
have fonned the most practical basis for detennining conservation reserves in the past, it is
unwise to assume that protecting examples of all of them will necessarily ensure that the
diversity of animals is also adequately conserved.
Importance of biodiversity
Biodiversity provides variety in human food and is the source of many medicines and
industrial products. It is also important in enriching human cultural life and stimulating
artistic endeavour. One of the great deprivations identified by people who have been
confined as hostages for long periods is the absence of other living things around them; the
sound of birds, the scent of flowers.
Plants and animals and their environments are major factors in attracting international tourists
with over 75 per cent identifying natural scenery and wildlife as key elements in their
decision to come to Australia. In addition, it has been estimated that at least 10 million
Australians visit natural environments each year and over four million visit major zoological
gardens (DEST, 1993). A household survey carried out by the Australian Bureau of Statistics
in 1993-94 revealed that 42.3 per cent of the Australian population over 18 years of age
visited at least one botanic gardens in the previous year (Fagg and Wilson, 1994).
Biodiversity is economically important in protecting water catchments from extreme events
such as floods and droughts. A Victorian Government sponsored study calculated the
financial benefit of water supplied to Melbourne from forested catchments at $250m per year
(Read, Sturgess and Associates, 1982). Not only is the yield from vegetated catchments more
consistent than from cleared catchments but the filtering process through leaf litter results in
water of high quality.
The top few centimetres of soil are fundamental to continued productivity of the land.
Diverse soil microorganisms living there are essential for litter breakdown and nutrient
recycling while plant roots in the zone prevent erosion and soil loss. Biodiversity in
microorganisms is also essential in the breakdown and absorption of many pollutants and
wastes created by humans.
New uses for plant biodiversity
The importance of native timbers in the Australian economy began with the export of the first
red cedar, commonly known as 'red. gold', from Sydney within seven years of settlement.
Although cedar logging had virtually ceased by the beginning of this century due to
overexploitation, eucalypt woodchips remain important, if somewhat contentious, export
products.
Australian Biodiversity Under Threat
10
Pharmaceutical products
An example of a less contentious use of a native plant product is the discovery of the
chemical compound conocurvone in a Western Australian smokebush belonging to the genus
Conospermum. Conocurvone has shown promise as a treatment for AIDS.
Following the discovery of conocurvone, the Western Australian Department of Conservation
and Land Management established three vital principles to be followed in further
development. These are:
• that the species be protected;
• that Australian science be involved directly in developing the compowld; and
• that in the event a drug is developed, then the community of Western Australia should gain
an equitable share of the profits (Letter from Acting Executive Director CALM to the
Editor, The Bulletin 7/1/93).
A research consortium of government and university scientists was established to develop
conocurvone to a marketable product. In addition to the phannaceutical aspects, research
involves determining methods of vegetative propagation and limits on wild harvesting of
smokebush.
The cost of developing a natural plant product into a marketable drug is enormous and the
Western Australian Government has joined with an Australian company to carry out further
research. It has been estimated that if the early promise shown by concurvone is realised and
it becomes a successful drug the State could receive royalties by the year 2002 of $100
million a year (Armstrong and Hooper, 1994).
Cutflowers
Export of native wildflowers and plants is an expanding industry which has grown from $2m
in 1981 to $22m in 1993. Almost two-thirds are fresh flowers from Western Australia but
dried flowers and foliage are also important and other states are now participating. The top
customer countries are Japan, USA, Germany and the Netherlands (RIRDC, 1994).
The domestic market for cut flowers is estimated to have a present retail value of S250-350m
but at this stage only 5-8 per cent of the market is native flowers with exotics like roses,
carnations and daffodils being more popular. This is clearly an area where national taste
could be changed.
Forest tree seed
Apart from limited alpine areas above the treeline, rainforest, extreme desert and some
treeless grassland, the Australian landscape is distinguished by gum trees and wattles. There
are more than 500 species of eucalypts, 800 species of acacia and I 200 tree species of
rainforest origin. Over 90 per cent of these species are found only in Australia.
Australian Biodiversity Under Threat
1J
About 200 tree species are commercially significant in Australia and overseas at this stage
and there is considerable interest in the potential of others for both their wood and
pharmaceutical products.
About 25~30 tonnes of tree seed worth S9m are exported annually to over 130 countries to
establish plantations for timber, firewood, amenity and erosion control. Export of this
amount of seed raises a dilemma in relation to access to Australia's unique forest genetic
resources (Fryer, 1994). On the one hand, it may be argued that Australia has relied heavily
on imported genetic resources for its agricultural industries and should reciprocate with forest
genetic resources. On the other hand the Convention on Biological Diversity encourages
countries to conserve genetic resources and to seek an appropriate share of the benefits. A
balance between 'free' exchange for research and development for commercial purposes needs
to be achieved. Fryer (1994) recommended that State and Commonwealth forestry agencies
develop policies which would meet commitments under international agreements while
protecting sovereignty over biological resources.
Land use and vegetation cbange
Past and present land use patterns
Australian land use has progressed through three major phases. The first ~as the Aboriginal
phase of hunting and gathering which lasted for more than 40 000 years. The second phase
covered just over a hundred years of European colonisation from 1788 to early this century.
It involved pioneering agriculture, grazing and timber harvesting. Mining was intensive
where it occurred but occupied only a relatively small part of the country.
The third phase from the early 1900s has seen consolidation of the pioneering efforts,
intensification of land use and large increases in land productivity where new scientific or
technical discoveries could be applied.
About 64 per cent of the country is allocated to agriculture and grazing. However, only 4 per
cent of this area is cropped and 6 per cent is sown pasture. The remaining 90 per cent is
modified or unmodified native vegetation some of which is vulnerable to clearing.
There has been an increase in the area allocated to mining as open-eut methods have been
developed for extraction of coal and iron ore. Beach sands have been mined for rutile and
zircon. Urban expansion, often onto agricultural land, and alienation of coastal and estuarine
areas for industrial, recreational and tourist activities have occurred. Even so, only about 0.6
per cent of the country is used for urban development, transport routes and mining although it
must be recognised that these activities have influences well beyond the area where they
occur. For example, urbanisation requires raw materials such as sand and gravel during the
construction phase and once established, draws on other land for water, food and recreation.
Australian Biodiversity Under Threat
In a discussion of vegetation clearance controls
emphasised that
In
12
South Australia, Bradsen (1994)
modem agriculture only exists because of the demands of cities which in tum can exist
only because of modem agriculture...it must be acknowledged that the whole community
has a responsibility, and a legitimate interest in, the sustainability of both agriculture and
biodiversity.
Australia has about 417 000 sq km of native forests but the area available for logging is only
about 134 000 sq k.m after inaccessible areas, roads, streambanks and other reserves are
excluded. There are 8 918 sq Ian of softwood and 846 sq Ian of hardwood plantations (RAe,
1991).
Land fonnally dedicated to nature conservation has increased to 403 867 sq km or about 6.4
per cent of the total land surface (Hooy and Shaugnessy, 1991). Aboriginal land occupies
about 12 per cent while the remainder is either unused or put to other undefined uses.
Vegetation change
Compared to other major inhabited regions of the world. Australia is the least forested,
making vegetation management one of the most important resource management issues
(Table 2).
Table 2
Forest cover in world regions
Geographic Region
Forest area 'OOOsq km
7916
Former USSR
7393
South America
4593
North America
3619
Asia (excluding USSR)
Africa
2359
1370
Europe
417
Australia
World Total 27667
Forest area as
percentage of total
land area
36
37
25
14
8
29
5
23
Source. AustralIan Academy a/ScIence, /994
An inquiry into the use of Australian forests and timber by the Resource Assessment
Commission (1991) found that about 50 per cent of forest had been cleared or severely
modified since European settlement. Calculations made by Wells, Wood and Laut
reproduced in the State of the Environment Source Book published in 1986 (Table 3) also
indicate about 50 per cent loss of forests.
Australian Biodiversity Under Threat
IJ
Table 3
Decline in forest cover 1788-1980
for each Australian State and mainland Territory
State or Territory
% with forest
cover 1788
NSW
Vic
Qld
WA
SA
Tas
NT
ACT
Australia
20
38
21
I
0.2
47
4
59
9
0/0 with forest
cover 1980
6
13
11
0.4
0.07
25
3
26
4.5
0.10 of original
forest cover lost
70
66
47
60
66
47
25
56
50
Source. State ofthe Environment In Australia. Source Book., AGPS /986
While loss of woodland has not been as great, it still amounts to about 35 per cent (Table 4).
There are more endangered and vulnerable plant species in some parts of the country than in
others. Figure 2 (see page 16) taken from Briggs and Leigh (1995 in press) shows the
number of threatened (endangered and vulnerable) plant species in each of 80 botanical
regions across Australia. Generally the high numbers occur along the eastern seaboard and in
the south-west of Western Australia where the greatest amount of clearing has taken place.
The high number in Cape York results from both clearing and overcolJecting of orchids and
ferns.
Examination of the figures presented in Tables 3 and 4 reveals that the percentage of forest
and woodland lost varies markedly from state to state with the south-eastern states, where the
majority of Australians live, suffering most. Even within individual states there is
considerable variation in intensity of clearing. In some cases this is related to the type of
native vegetation and new technology. For example. 'the development of new clearing
techniques has allowed the almost complete destruction of the brigalow and now, the poplar
box woodlands' (in Queensland) (Kirkpatrick, 1994).
Australian Biodiversity Under Threat
14
Table 4
Decline in woodland cover 1788-1980
for each Australian State and mainland Territory
State or Territory
NSW
Vic
Qld
WA
SA
Tas
NT
ACT
Australia
woodland
cover in 1788
0/0
57
34
28
14
6
31
22
38
23
0/0
31
8
20
9
3
20
22
13
15
woodland cover
in 1980
of original
woodland cover
lost
46
76
28
36
50
35
0/0
66
35
Source. State o/the EnVIronment In Australta. Source Book. AGPS 1986
The mean annual deforestation rate for forest and woodland from 1788-1985 has been
estimated at 359 OOOha or 0.09 per cent per annum (AUSLIG, 1990) (Forest and woodland
were defined as natural vegetation dominated by trees. excluding mallee and mangroves).
Estimates compiled recently for the National Greenhouse Gas Inventory reveal that the
annual rate of clearing forest and woodland, largely for agriculture, between 1983-93 was
568 OOOha, far exceeding the average annual rate for the past 200 years. Even more alarming
are the annual figures for the latter part of this decade. In 1988,719 OOOha were cleared and
in 1990 the figure still reached 665 OOOha (NGG1 Committee, 1994).
These figures were obtained from a range of sources within each state and territory.
However, the Inventory includes the qualification that '...these figures are very preliminary
estimates which we have no way of verifying until land clearing rates can be developed using
remotely sensed data'. Even with this qualification, however, the present rate of clearing far
outstrips the capacity of any programmes to 'regreen' the country. For example, the One
Billion Tree program is likely to replant at best 50 OOOha per year. While it is significant in
addressing the most denuded areas and is supported by other Landcare programs such as Save
the Bush, the gap between treed and untreed land can only widen dramatically each year if
present clearing rates are allowed to continue.
Clearance is usually expressed in hectares while planting is expressed in numbers of trees.
This obscures the reality that some areas of malIee have a tree density before clearing of
I 000 trees per hectare. 'In blue gum woodland and stringy bark woodland numbers of
significant or mature trees are estimated to range between 50-100 and 100-900 trees per
hectare respectively' (Bradsen, 1995). Where understorey plants are concerned, the figures
are far higher. For example, counts of up to 7 900 broom bush per hectare have been
recorded where it is relatively pure and 5 200 as a combined understorey on Kangaroo Island
(Bradsen, 1995).
Australian Biodiversity Under Threat
/5
It must also be recognised that clearing removes not only the trees but the shrubs. grasses and
other small plants which comprise the whole plant community. When the plants are lost so
are the animals including the insects and often the soil fauna which depend upon them.
Most clearing is occurring in Queensland and NSW; 450 OOOha and 150 OOOha respectively in
1990. Areas cleared in Victoria, Tasmania and South Australia were much less: 6 156ha,
5 999ha and 4 471 ha respectively.
The dynamics of vegetation change are reflected in results published by AUSLlG, 1990, and
presented in simplified form in Table 5 taken from the Australian Academy of Science
textbook for senior school students Environmental Science.
The biggest change in the type of vegetation cover between 1788 and 1980 has been the
increase of 130 per cent in the area of grasslands and pastures at the expense of the forest,
woodland and shrubland.
Grassland in southern Australia, however. is now dominated by exotic grass species. The
sweeping expanses of native grasses which excited early explorers like Major Mitchell have
been lost. It is estimated that a staggering 99.5 per cent of native grasslands in Victoria have
been destroyed in only 150 year.; (Scarlett et aI, 1992). Not only have the native grasslands
species gone but also the animals that lived there.
This loss of grassland species is exemplified in a record by pioneering journalist John Gale
published in 1927. While walking through what is now the centre of Canberra, John Gale
came across a flock of plain turkeys (bustards) 'scores in number' which 'continued feeding.
merely parting to permit my passing though the flock' (Gale, 1927).
The only turkeys to be found now in Canberra are domesticated ones in supermarket freezers!
A massive reduction in the rate of clearing native vegetation accompanied by replanting
native species of trees, shrubs and grasses is essential if further loss of plant and animal
species is to be avoided. Existing remnants of native vegetation must be protected and
encouraged to expand to fonn first corridors and then broad superhighways linking national
parks and nature reserves.
.-
Australian Biodiversity Under Threat
•
•
.
...
Figure 2: Distribution of threatened (endangered and vulnerable)
plant species.
Source: Briggs, 10 and Leigh, JH (1995), Rare or ThreaJened Australian Plants, 1995 Revised
Ed. CSIRO Melbourne (in press).
16
Australian Biodiversity Under Threat
/7
Table 5
Changes in vegetative cover between 1788 and 1980
(thousand sq km)
1788
Vegetation
1980
690
1 570
1650
1610
1470
500
Forest
Woodland
Open woodland
Shrubland
Open shrubland
Grassland and
pasture
Changes in cover
%
390
1070
2000
860
2020
1 150
-43
-32
+21
-47
+37
+130
Source. EnVIronmental &tence, AustralIan Academy a/Science, /994
Tbreats to diversity
Species lost and under threat
Since European settlement began, about 74 species of flowering plants and 41 species of
birds and mammals have become extinct. Many others are threatened with extinction unless
actions are taken to remove or relieve the threatening processes.
Species which are presumed extinct, endangered or vulnerable on a national basis are listed in
schedules to the Endangered Species Protection Act 1992 which came into effect on 30 April
1993 (Table 6). See also Figure 2, a map of threatened Australian plant species.
Table 6
Numbers of endangered, vulnerable and presumed extinct species
in Schedule 1 of the Endangered Species Praleclion Act 1992 (at 30 April 1993)
Endangered
Groups
Fish
Amphibians
Reptiles
Birds
Mammals
Plants
Total
7
7
6
25
28
226
229
Vulnerable
Extinct
6
2
15
25
18
660
0
0
0
20
21
74
726
115
Source. Austrahan Nature ConservatIon Agency, /994
Note: There is no /isting/or invertebrates, e.g., insects
Other schedules to this Act provide for listing endangered ecological communities and key
threatening processes. No ecological communities have been scheduled to date although a
discussion paper has been released which outlines the views of the Endangered Species
Australian Biodiversity Under Threat
/8
Scientific Subcommittee on the process proposed for listing endangered ecological
communities under the Endangered Species Protection Act (Endangered Species Scientific
Subcommittee, 1995).
Key threatening processes listed in Schedule 3 of the Act are:
•
Predation by the European red fox (Vulpes vulpes);
•
dieback caused by the root-rot fungus (Phytophthora cinnamoml);
•
predation by feral cats;
•
competition and land degradation by feral rabbits; and
•
competition and land degradation by feral goats.
Leigh and Briggs (1992) identified grazing and agriculture, mostly following clearing, as
responsible for well over 90 per cent of plant extinctions and by far the major present and
future threat to plant species classified as endangered nationally.
The question must be asked: when will 'excessive vegetation clearing' be recognised as a 'key
threatening process' in the Commonwealth Endangered Species Protection Act?
Loss of habitat
One of the difficulties in gammg general acceptance of the significance of habitat loss
through clearing arises because a few very obvious animals, including the larger kangaroos
and some parrots, have actually increased in numbers as land has been cleared and pastures
established. The )994 commercial culling quota set by governments for large kangaroos was
4170100.
The land development ethic which prevailed in Australia gave credit to those who cleared the
bush to make way for cows, sheep and wheat. Eucalypts were regarded as the farmer's
enemy_ Before the bulldozer appeared after World War n they had to be removed laboriously
by hand but 'shot up again as soon as your back was turned'.
Hunting individual animal species like the koala and harvesting specific timber species like
red cedar were obvious actions exerting direct pressure on species. By contrast, loss of
habitat is more insidious and less subject to public criticism.
TIlis anomaly is epitomised in the old English verse:
The law goes hard on man or woman
Who steals the goose from offthe common
But lets the greater sinner loose
Who steals the common from the gOOje.
Australian Biodiversity Under Threat
/9
Activities which foHow clearing such as introduction of exotic crops and grasses. fertilisers.
pesticides. weeds, exotic animals and subsequent increases in erosion and soil salinity all
make it more difficult for remnant habitat to survive and native plants and animals to
recolonise.
Extensive clearing on private land has relegated many rare plants to roadsides where they are
vulnerable to weed competition, changes to the water table, dust, pollution from motor
vehicles and direct damage during vegetation control methods involving mowing and use of
herbicides. Animals sheltering in roadside remnant vegetation are vulnerable to similar
adverse effects and have the added risk of being killed by vehicles.
The koala, one of Australia's national symbols, is a striking example of the impact on species
numbers through loss of habitat. Leaves from only a few species of eucalypt are an essential
component of the koala's diet. Although it will eat leaves of other eucalypts and sometimes
even other types of tree, one or two particular species always fonn the major part of the diet.
Koalas are found natura1ly only in forests containing these particular trees and as forests have
been cleared koala numbers have declined. This is illustrated in Figure 3 showing the
probable range of the koala in 1788 compared to the very limited current distribution.
,
"',
..
.,"
",
pr~blf"ange
Dol ~l.n in 1788
.~pproIim.J11.' curr('fll
d,lol"l>l>llon 1b.1\.<.-d
on siJ:h1inlo-s in r~"Ccnl
N~'ooruJ KU.lI~ Sur'...."1
Figure 3: The distribution oftbe koala
Source: £m>ironmental Science. 1994 Australian Academy a/Sciences.
derivedfrom ECOS 735 Spring /992 CSIRO
Australian Biodiversity Under Threat
20
Other threats beside loss of habitat include feral animals and weedy plants. dieback disease.
uncontrolled fire, erosion and soil loss. illegal trapping of animals (particularly birds and
reptiles), illegal harvesting of plants such as orchids and palms. and uncontrolled use of
herbicides.
Feral animals and weeds
About 73 vertebrate animals have been introduced and become established in the wild since
European settlement. In addition, there are many introduced insects, other invertebrates such
as snails, and disease-causing organisms.
Introduced animals which have had major direct effects on native species through predation
include the domestic cat. wild dog and fox. For example, foxes and feral cats contribute
significantly to the endangered status of both malleefowl. Leipaa acellata, and the western
swamp tortoise. Pseudemydure umbrina.
Introduced animals which have destroyed habitat and have thereby adversely affected native
animal species include the rabbit. feral pig. horse, donkey. water buffalo. camel and European
carp. The vulnerable status of the Lord Howe Island Woodhen, Tricholimnas sylverstris. is
due in part to egg predation by rats and habitat damage by pigs and goats introduced to the
island. Similarly. the vulnerable status of the bilby, Macro/is lagatis, is due in part to
competition with rabbits for burrows.
At least 2 000 exotic plants are now a pennanent part of the Australian biota. Ross (1976)
calculated the rate of introduction of non-Australian plant species to Victoria had averaged
five to six species per year over the previous 100 years and there was no sign that this was
diminishing.
The estimated total cost of weeds to Australia annually is $4 DOOm (Australian Horticulture,
1991) and the annual losses due to one species, blackberry, in New South Wales. Victoria and
Tasmania rose from $42m in 1988 to at least $77m in 1990.
These costs relate primarily to the impact on agricultural and pastoral production. However.
some weeds are major problems in conservation reserves and have the potential to reduce
biodiversity through competition. Bitou bush, Chrysanthemoides monilifera, has become a
major problem invading coastal vegetation; giant sensitive plant, Mimosa pigra, has
colonised floodplains in the top end of the Northern Territory; and Athel pine. Tamarix
aphylla. is expanding in some of the dry river beds in Central Australia.
In some cases introduced species may cause genetic contamination. For example, Norfolk
Island pine. Araucaria he/erophylla, is endemic to that South Pacific island and is the only
species of Araucaria occurring there. A small plantation of Queensland Hoop pine,
A.cunninghamii. was established on Norfolk Island but was subsequently removed to prevent
the possibility of hybridisation and consequent genetic contamination of the native Norfolk
Island pine.
Australian Biodiversity Under Threat
]J
Introduced honey bees may have adverse effects on native bees and pollination of some
native plants. Commercial beehives are now prohibited in some conservation areas.
Leigh and Briggs (1992) estimated that weed competition was the cause of extinction of four
plant species. It was also the past threat to 12 and the present and future threat to 57 species
now classifled as endangered.
Erosion and soil degradation
Soil erosion following a combination of excessive tree clearing, extension of cropping into
marginal lands, droughts and feral animals such as the European rabbit, is the major factor in
soil degradation in Australia. A national survey in 1975 revealed that degradation had
occurred on 55 per cent of the arid zone due largely to deterioration of vegetation followed by
wind erosion. In the non-arid zone 68 per cent of extensive cropping land, 63 per cent of
intensive cropping land and 36 per cent of grazing land had deteriorated to the extent that
remedial work was needed. In present values, the cost of construction works to treat land
degradation is estimated to far exceed $A2 billion (Robert, 1989).
High salt levels are typical of large areas. Salinity problems have been exacerbated by land
management involving removal of tree cover with subsequent rises in the water table. The
problem of high salt levels has increased markedly in irrigated areas and 10 000 sq kIn in the
non-arid zone are considered degraded through salinity.
Fire
Many Australian plants are adapted to fire and may even require burning to open woody
fruits or crack hard seed coats. However, if plants do not have time to mature and produce
seed 'between burns they may be replaced by other species. The fire frequency for heathland
is about ten years and more frequent burning will lead to the disappearance of some heath
plants. Birds such as ground parrots tend to disappear from heath if the fire pattern does not
ensure their food supply.
High intensity wild fires such as those which occurred in New South Wales in 1994 can
destroy local populations of animals unable to fly or flee from the fire. This aspect is
particularly important for sedentary animals in relatively small patches of remnant vegetation
where recolonisation after fire is difficult and any animals which do survive the fire may
starve through loss of food plants.
Dieback disease
Dieback disease caused by the cinnamon fungus, Phytophthora cinnamomi, is widespread
across Australia and is of particular concern in the south-west of Western Australia where it
has spread into some conservation reserves. About 50 per cent of Cape Ie Grande National
Park and more than 20 per cent of Stirling Range National Park are infected. The Western
Australian Department of Conservation and Land Management also estimates that 70 per cent
of Two People Bay Nature Reserve, habitat for the vulnerable noisy scrub-bird, Atrichornis
clamosus, is infected by a combination of dieback and aerial canker.
Australian Biodiversity Under Threat
22
Dieback fungus attacks plants at their roots preventing uptake of water and nutrients to the
stems and leaves. PI~ls may collapse within two weeks of infection.
It is estimated that 2 000 plant species are threatened including banksias which are important
in the wildflower trade and honey industry and as a food source for many birds and small
mammals.
Cinnamon fungus has already struck heathlanc\s in Tasmania, rainforests in Queensland and, to a lesser
extent, the eucalyptus forests of New South Wales and Victoria. Hardest hit are the jarrah forests of
Western Australia (Sydney Morning Herald. 24 September 1994).
The fungus is spread when infected soil is moved from place to place by bushwalkers,
vehicles, roadworks and even sharp-hoofed feral pigs and native animals with dusty paws.
No cure has yet been found and control centres on quarantining infected areas and complete
washdown of vehicles moving through these areas.
As indicated earlier Phytophthora cinnamomi is listed as a key threatening process in the
Commonwealth Endangered Species Protection Act (1992).
megal trapping
Illegal trapping of fauna and harvesting plants has a severe conservation impact when it is
concentrated on uncommon and threatened species which have special appeal to collectors
because of their rarity. There is often associated cruelty to animals when attempts are made
to hide them during transport either within Australia or to overseas destinations. Birds and
reptiles are the main animal targets while orchids from North Queensland have a ready
market overseas.
Conserving biodiversity
Plant communities
Much of the effort in biodiversity conservation has been directed. at identifying and protecting
rare and threatened. species. Without this effort more species would become extinct and there
are very few people who would consciously wish to add to the number of species now known
only from herbarium and museum specimens. Australia already holds the record for the
highest number of mammal extinctions of any country. a record which cannot be held with
any pride.
In general, public sympathy and support is easier to muster for an endangered species than an
endangered community. This explains in part why public appeals to save the helmeted
honeyeater, Lichenostomas me/anops cassidix, or the northern hairy-nosed wombat,
Lasiorhinus krefjiii, are more successful than appeals to conserve the community or habitat
where they live. Sometimes of course, an animal can be a focus of interest for habitat
conservation as in the case of the long-footed potoroo, P%rous /ongipes, in the south-eastern
forests of New South Wales.
Australian Biodiversity Under Threat
23
Emphasis on species conservation has, however, overshadowed the need for community
conservation and more attention must be given to this aspect in the interests of conserving
biodiversity.
The importance of community conservation is evident in the example of the interaction of the
sugar glider, black wattle, apple box and scarab beetle. Sugar gliders are common in eucalypt
forest and woodland although being nocturnal, they are not often seen. They feed on scarab
beetles, eating up to 1S large adults per hour at night when the beetles are active. Scarab
beetles feed voraciously on eucalypt foliage, sometimes causing defoliation.
Their
appearance is seasonal, however, and sugar gliders must have alternative food when scarab
beetles are absent. Research in Victoria has shown that gums produced by black wattle and
apple box are the major food for sugar gliders in winter. Tree hollows, groundcover,
flowering trees and shrubs also improve the habitat for gliders although without black wattle
they will not survive through winter. In the absence of gliders, scarab beetles may increase in
numbers to the point where trees are defoliated and dieback sets in (Smith, 1993). If trees
die, the watertable rises, bringing salts to the surface and resulting in soil degradation and
poor quality runoff water.
Major advances in developing techniques for direct sowing of native seed mixtures
helped to improve opportunities to reconstruct plant communities but we need to learn
about seed ripening times and gennination requirements There are major long
biodiversity advantages in attempting to restore communities rather than replanting
alone.
have
more
tenn
trees
Research and survey
Research and survey is fundamentally important to Australian nature conservation.
Universities, museums, herbaria, zoological and botanical gardens, various divisions of
CSIRO and territory, state and Commonwealth departments all play important roles with
funding provided by governments directly and through private agencies such as the
Worldwide Fund for Nature.
Much of Australia's biodiversity is still not studied (Richardson, 1984). More than SO per
cent of the estimated 200 000 Australian invertebrate species and 2S per cent of higher plants
remain to be described. Historically, scientific effort has been concentrated on conspicuous
elements of the flora and fauna. Organisms such as fungi, protozoa and arthropods which are
fundamental to the function of terrestrial ecosystems have been ignored.. These organisms are
integral to such diverse functions as biogeochemical cycles, nutrient uptake, maintenance of
soil fertility and pollination (House of Representatives Standing Committee on Environment,
Recreation and the Arts, 1992).
Some conservation reserves have been established without detailed surveys of flora and fauna
within them. Such surveys are essential as a basis for monitoring the effects of management
to ensure that the values which justify reservation are being retained.
Surveys may uncover unknown species, greatly enhancing the scientific value of the reserve.
The recent discovery of a previously unknown species of native conifer in a secluded gorge in
the Wollemi National Park in NSW is a prime example (The Canberra Times 1S December
Australian Biodiversity Under Threat
24
1994). There appear to be only forty specimens of this tree whose closest relatives are fossil
Araucarites known only from the Jurassic and Cretaceous periods 200 to 65 million years
ago. This discovery is as significant to science as that of the dawn redwood, Metasequoia
glyptostroboides, in a remote valley in China in 1941. Millions of dawn redwoods are now
grown as ornamental trees and Wollemi pine may have similar potential.
Volunteers are playing an increasing role in research and survey work. The Atlas of
Australian Birds produced by the Royal Australasian Ornithologists Union in 1984 was based
on observations by more than 3 000 volunteers 'who had passively watched birds in their own
backyards from Cairns to Perth, Wyndham to Oodnadatta' and then 'trekked into the outback'
(Blakers, Davies, Reilly, 1984).
The Western Australian Department of Conservation and Land Management now runs a
program where volunteers actually pay for the opportunity of joining expeditions to work
with research scientists in the field.
One of the consequences of having such a diverse flora and fauna with so many endemic
species is that ecological and conservation based research must be carried out in Australia. It
cannot be carried out in other countries.
Apart from the human 'need to know' which has always driven inquiry. competent research
and implementation of findings is an investment in ensuring that Australia's biodiversity
continues to anract international tourists.
International conservation agreements
Australia's strong commitment to international conservation agreements since the 1970s has
often been clouded in controversy over 'states' rights' although supported in principle.
A list of agreements to which Australia is a party (Appendix) is a measure of national and
international concern for nature conservation. It is also clear recognition that, despite our
geography, Australia is part of the world scene where migratory birds and marine species and
international trade in wildlife are concerned.
Implementation of these agreements is provided for in nature conservation legislation which
regulates management of conservation reserves and protection of native plants and animals
both in reserves and on other public and private land.
Parks and reserves system
The national parks and reserves system on public land which began in earnest with the
establishment of Royal National Park south of Sydney in 1879, the second only in the world, is a
fundamental component of conservation of biological diversity. In fact, it 'is the major tool
presently available to protect biodiversity' (Flannery, 1994).
The reserve system has grown remarkably in the last 115 years and now covers 50 million
hectares or about 6.4 per cent of the country. Like many other activities in Australia, the pattern
of development varied from state to state and there was no national approach. In some cases,
Australian Biodiversity Under Threat
25
reserves stopped at a state border even though the same habitat continued into the adjacent area
and was in equal need of protection.
Attempts to examine the adequacy of the reserve system in covering the diverse range of
ecosystems have long been made by academics and organisations like the Australian Academy
of Science. It was not tackled at the parliamentary level, however, until 1970 when the House of
Representatives established a Select Committee to inquire into the state of wildlife conservation
in Australia.
The Select Committee considered the adequacy of the national park and reserve system and
recommended:
That a national policy be initiated aimed at acquiring such portion of the total land area of each State and
Territory in the fonn of secure national parks and reserves as will ensure that all habitat types will be
preserved (Recommendation 2(a), House of Representatives Select Committee on Wildlife Conservation,
1972).
The area of national parks and reserves at 30 June 1972 was 16 001 921ha or 2.1 per cent of
the country. Although it now occupies 6.4 per cent it still does not fully represent the range
of Australian biodiversity.
In 1993 the House of Representatives Standing Committee on Environment, Recreation and
the Arts inquired into the role of protected areas in conserving biodiversity. The Committee
heard evidence of major gaps in the system and recommended:
that, in setting up a core protected area system nationwide, the Commonwealth set as a minimum
target the representation of at least 80 per cent of bioregional ecosystems in core protected areas by the
tum of the century (House of Representatives Standing Committee on Environment, Recreation and the
Arts, 1993.)
(7)
The Committee recognised a need for definition and agreement between the States,
Territories and the Commonwealth on the range of bioregions and urged the Australian and
New Zealand Environment and Conservation Council, ANZECC, to address this.
An Interim Biogeographic Regionalisation of Australia, IBRA, project has been initiated by
the Australian Nature Conservation Agency working with State and Territory agencies and
80 bioregions identified (Thackway and Cresswell, 1995). When these are validated and
overlaid by the existing reserve system they will form an agreed basis for determining
priorities in land reservation for Commonwealth funding under the National Reserves
System Cooperative Program, NRSCP (ANCA, 1994).
Other public lands
The great diversity which exists in Australian flora and fauna together with the fact that
many species occupy small ranges scattered across the continent mean that:
To protect all biodiversity within reserved lands would require a huge increase in the reserved lands
system (Flannery, 1994)
This is not likely to occur, and other means of conserving biodiversity will need to be found.
Society will also have to make some difficult decisions on the amount of biodiversity which
is needed or can be afforded.
Australian Biodiversity Under Threat
26
While national parks and nature reserves are the mainstay of nature conservation, other
public lands (and private lands, see below) have important roles to play. Forestry legislation
in all states provides for areas within state forests to be set aside for special purposes
including conservation of flora, fauna and landscapes (Boden, )984). In some cases the
areas are regarded as reference stands which can be used to assess the effects of forest
management. In others, they have been established to protect rare species. For example, the
Bunal Forest Preserve near Inverell in NSW contains Baker's mallee, Eucalyptus bakeri, and
several other unusual tree occurrences; and the Whipstick Forest Park near Bendigo in
Victoria includes the rare Whirrakee wattle, Acacia williamsonii.
Road and rail easements are significant areas of public land. In Victoria, for example, roads
occupy about 2.5 per cent of the state. In 1987 there were 870 OOOkm of roads in Australia.
While a large part of the road reserve is dedicated to its primary purpose of carrying traffic,
there are often extensive verges in rural areas which are important habitat for plants and
some animals.
Remaining native vegetation on roadsides often provides evidence of the type of vegetation
which occurred before adjacent paddocks were cleared and is therefore a useful guide to
rehabilitation programmes. They are also seed reservoirs for revegetation projects if
harvested carefully. A measure of the importance of road and rail reserves as habitat for
threatened plants lies in the fact that roadworks are the major threat to 61, or more than a
quarter of species classified as endangered (Leigh and Briggs, 1992).
Linear easements, including fonner stock routes, act as corridors for wildlife movement and
may be particularly important in assisting some species to move from areas which are burnt.
Sugar gliders have been known to disperse more than one kilometre along roadside corridors
and can survive at high densities in linear forest habitats of little more than a single tree in
width. Ironically, they may initially survive better than the trees themselves which suffer
when reduced to a thin band exposed on both sides.
The significance of road easements for biodiversity conservation has been recognised by the
Australian Road Research Board which has prepared a draft National Strategy for Roadside
Reserve Management (Farmar-Bowers, 1994).
Private and leasehold land
The area of nature conservation reserves on public land has increased markedly in recent
years. 1bis often appears to be stimulated by imminent elections suggesting the political
importance attached to this aspect of nature conservation. Unfortunately, additions to the
reserves system have occurred at times of shrinking management resources, including staff
numbers. There is therefore a growing perception that present reserves are not adequately
managed. This has increased opposition among some rural communities to further
acquisitions.
Under these circumstances, innovative ways need to be found to encourage landholders to
manage native vegetation on their land for conservation rather than relying only on the
public reserve system.
Australian Biodiversity Under Threat
27
Two-thirds of the State of Victoria is privately owned and some of it contains important
habitats not represented on public land. Between 80 and 95 per cent of the original native
vegetation in the wheat belt of NSW has been cleared and what little remains is on private
land (Sivertsen, 1994).
A Land for Wildlife Scheme has now been operating successfully in Victoria for several
years. Over 2 500 properties covering more than 270 OOOha of private land of which some
5 000 - 7 OOOha are managed for wildlife, are participating. The brolga, Grus rubicundus, is
a majestic bird standing up to 1.4 metres tall and living for forty years. It fonnerly occurred
in large numbers in Victoria but only about 600 birds now remain there. About a third of
this population migrates each year to the southern Grampians in Western Victoria where
they forage for fallen grain and insects in stubblefields after the wheat, barley and oats have
been harvested. Pizzey (1994) believes these birds rely:
... for nearly six months every year on the tolerance, goodwill and generosity of a few dozen private
landholders.
The display perfonned by this magnificent bird is as elegant as Graham Pizzey's eloquent
description of it:
As they drop steeply to earth with raised necks and lowered legs, several indulge in wild aerobatics.
Once down, they leap and bow, toss tufts of straw in the air, go bounding off with widespread
wings...For brolgas. and everything a brolga does is touched with a wild spirit.
While it is appreciated that this type of conservation is species rather than communityoriented, it is biologically significant for a nomadic or migratory species like the brolga and
valuable in stimulating public interest in wildlife conservation.
The 'stick' approach to protecting native vegetation on private land comes from controls on
land clearing. South Australia pioneered the concept of clearance controls and voluntary
Heritage Agreements in the Native Vegetation Management Act 1985. This legislation was
replaced by the Native Vegetation Act 1991 which controls the clearance of native vegetation
as well as having a number of initiatives to assist conservation, management and research of
native vegetation on lands outside the declared parks and reserves system.
An analysis of the perfonnance of the scheme since it was introduced in 1985 has recently
been prepared by J R Bradsen, Chainnan of the (SA) Native Vegetation Council, which is
responsible for decisions on clearance applications and for providing advice to the Minister
of Environment and Land Management on the condition of native vegetation in South
Australia (Bradsen, 1995).
An integral part of the legislation provides for Heritage Agreements between the landowner
and the State Government for the protection in perpetuity of a particular area of native
vegetation. The landowner retains ownership of the property and there is no right of public
access without landowner approval. In return for entering into the Heritage Agreement the
landholder may be compensated for the cost of fencing to protect the area from grazing, may
be released from rates and taxes on the land, and may receive some management assistance
through the Native Vegetation Fund.
Australian Biodiversity Under Threat
28
By 1994 more than 850 agreements had been signed for the protection of 550 OOOha of
bushland. Areas of land covered by individual agreements range in size from about two
hectares to 10 OOOha with an average size of about 400ha. Assuming a natural stocking rate
of between 300 and 400 trees per hectare this amounts to saving about 200 million trees and
the associated understorey.
Some other states have introduced similar schemes and the Australian and New Zealand
Environment and Conservation Council has recently established a working group to develop
a coordinated national approach to nature conservation on private land. One scheme to be
assessed for suitability to the Australian scene is the Ecological Sensitive Area concept now
being applied in the European Union (Bridgewater, 1994).
In South Australia over $70 million in financial assistance has been paid to landowners who
have entered into heritage agreements to save bushland on their fanns. This may seem a
high figure but it is only about 35 cents per tree saved. It is less than the cost of planting and
has the added benefit of saving the interacting plant and animal community.
The tenn intergenerational equity has now joined biodiversity as part of the common
language. Stated simply, it means ensuring that children and grandchildren inherit a country
as rich and diverse as their parents and grandparents did. The ethos of intergenerational
equity, which most Australians know better as 'wanting to look after the kids', is expressed
most strongly in times of war. It should be expressed equally strongly now in the battle to
conserve biodiversity.
Australian Biodiversity Under Threat
29
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Australian Biodiversity Under Threat
32
Appendix
International Conservation Agreements to which Australia is a Party
Antarctic Treaty
China-Australia Migratory Birds Agreement (CAMBA)
Convention Concerning the Protection of the World Cultural and Natural Heritage
Convention for the Conservation of Antarctic Seals
Convention for the Protection of the Natural Resources and Environment of the South
Pacific Region
Convention on Biological Diversity
Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)
Convention on the Conservation of Antarctic Marine Living Resources
Convention on the Migratory Species of Wild Animals (CMS)
Convention on the Conservation of Nature in the South Pacific
Convention on Wetlands of International Importance (Ramsar)
International Tropical Timber Agreement
Japan-Australia Migratory Birds Agreement (JAMBA)
Plant Protection Agreement for the South-East Asia and Pacific Region