Chapter 1 Introduction to biodiversity and the inquiry
Biodiversity is the variety of life. It includes not only the
diversity of species of plants, animals, fungi, bacteria and viruses that
inhabit our planet, but also the genetic material within those species, the
diversity of ecosystems, habitats and communities within which they live, and
the diversity of processes that are performed by genes and species and the
interactions among them.[1]
1.1
Australia has a rich biodiversity, with between 7 and 10 per cent of all
species on Earth occurring here.[2] There are between 600 000
and 700 000 species found in Australia, many of which are unique (endemic) to
the country.[3] The main drivers
affecting the state of the environment are recognised as being climate change,
population growth and economic growth.[4]
1.2
In recognition of the immensity and relevance of these issues in current
debates and challenges facing government in Australia and internationally, the
Committee sought to conduct an inquiry into climate change impacts on
biodiversity, and on 2 June 2011 adopted broad terms of reference, with a focus
on nationally important ecosystems.
Conduct of the inquiry
1.3
The Committee received 89 submissions, 14 supplementary submissions and
60 exhibits. Based on those submissions, public hearings and site inspections
were held in each state and territory. In the course of these site inspections,
the Committee received extensive and valuable evidence on aspects of climate
change impacts in nationally important ecosystems. As a result, two interim
reports were published in May and November 2012. The interim reports provide a
useful platform on which this final report is based. Without duplicating the
narrative of the interim reports, some themes are further developed in this
final report, which takes a more strategic focus and makes recommendations for
changes to administration and policy in biodiversity conservation and related
areas.
1.4
The first interim report (May 2012) reviewed site inspections conducted
in south-west Western Australia, an internationally recognised biodiversity
hotspot; the Tasmanian Midlands and Central Plateau; the New South Wales Snowy
Mountains region, and areas around Sydney, NSW, which included biodiversity
conservation programs in urban areas.[5]
1.5
The second interim report (November 2012) reviewed museums and bird
habitats in Victoria, water and biodiversity in South Australia, Kakadu
National Park in the Northern Territory and the Wet Tropics of Queensland World
Heritage Area and Reef HQ Aquarium in Queensland.[6]
1.6
In conducting such a comprehensive inquiry, the Committee focussed on
the likely impacts of biodiversity if climate change projections are realised,
and the resultant implications for management and policy-making in biodiversity
conservation. The Committee did not focus on the causes of climate change or
sustainable population growth as relating to biodiversity. As the terms of
reference required, attention was given to ‘nationally important ecosystems’,
although themes and issues considered by the Committee in its 2009 report into
managing Australia’s coastal zone continued to inform members’ deliberations.[7]
Structure of this report
1.7
As noted earlier, both interim reports provided a platform; a means to
explore themes common to more than one term of reference, and across nationally
important ecosystems. For example, community engagement was a theme in projects
in most states, and across most ecosystem projects, although some of the challenges
faced by the projects may have related specifically to data-collection, or the
nature of the threat from pests or invasive species. An inquiry of this breadth
and complexity will inevitably produce many areas which ‘overlap’, and
structuring the interim and final reports to reflect these complexities will
inevitably result in intersecting discussions across some terms of reference.
1.8
The remainder of this chapter will follow the first term of reference,
and examine the state of Australia’s terrestrial, marine and freshwater
biodiversity.
1.9
Chapter two considers the third term of reference, and examines the
effects of biodiversity loss on human communities. Ecosystem services are
discussed, and conclusions and recommendations are made in relation to national
environmental accounts and citizen science initiatives.
1.10
Chapter three examines examples of the sustainable use of resources
encountered by the Committee, particularly during site inspections. Considering
the fifth and seventh terms of reference, the Committee acknowledges the
importance of government support for such initiatives and the benefits for
community engagement.
1.11
Chapter four considers connectivity conservation as a management
approach in a changing climate, following the second term of reference, and
also explores community engagement and the National Reserve System.
1.12
Chapter five examines climate change adaptation strategies in relation
to mitigation, resilience and adaptive management, as well as the resources
required to support these strategies. In considering the fourth term of
reference, conclusions and recommendations are made on a range of issues
including funding, the National Plan for Environmental Information, and
national biodiversity databases.
1.13
Chapter six considers the effectiveness of the natural resource
management structure in Australia, including its funding and the need for
regional approaches; these relate to the seventh term of reference.
1.14
Chapter seven assesses governance issues relating to the Environment
Protection and Biodiversity Conservation Act 1999 (Cth), international
obligations, cross-border management and integrated forest management,
following the sixth term of reference, and makes recommendations accordingly.
1.15
Aspects of community engagement, as referred to by the seventh term of
reference, are relevant to many areas of the report, and are therefore
considered in chapters two, three, four and six.
The state of Australia’s biodiversity
1.16
The Committee considered the state of biodiversity in terrestrial,
marine and freshwater environments, as well as examining biodiversity
‘hotspots’. The current state of these different environments and hotspots will
be canvassed, followed by an outline of threats, and current and projected
losses to biodiversity. Climate change is seen as an additional stressor on
biodiversity in each of these environments, to varying extents and with varying
effects. Some of the threats posed by climate change will then be discussed in
general terms, followed by a specific focus on marine and freshwater ecosystems.
At the conclusion of this chapter, observations of the Committee across its
range of site inspections are summarised, demonstrating the range of impacts
and the extent of variability.
Terrestrial
1.17
There are 85 bioregions in Australia, representing vast and diverse terrestrial
ecosystems including deserts, rangelands, tropical monsoon rainforests,
temperate grasslands, wet eucalypt forests, alpine regions, and sub-Antarctic
and Antarctic regions in the external territories.[8]
1.18
As mentioned above, there are many endemic species in Australia’s
terrestrial environment, including:
n 1350 endemic
terrestrial vertebrates
n 305 terrestrial
mammal species, of which 85 per cent are endemic
n 89 per cent of
reptile species
n 94 per cent of frog
species
n 45 per cent of bird
species
n 17 580 species of
flowering plants, of which 91 per cent are endemic.[9]
1.19
The 2011 State of the Environment report assessed terrestrial plant
species in ‘high-altitude, remote and/or very dry parts of Australia’ as in a
good state, with adequate high-quality evidence and a high level of consensus
supporting the assessment. Recent trends indicated that the assessment was
stable, with limited evidence or limited consensus.[10]
1.20
The outlook was not as positive for terrestrial birds, reptiles and
amphibians, which were all assessed as in a poor state, with recent trends
indicating that state was deteriorating, with limited evidence or limited
consensus on both the assessments and the trends. Terrestrial mammals fared
even worse, being assessed as in a very poor state, with recent trends
indicating that state was deteriorating, with limited evidence or limited
consensus on both the assessments and the trends.[11]
1.21
Terrestrial invertebrates were assessed as in a poor state and the trend
as being unclear, with evidence and consensus too low to make a confident
assessment on both the state and trend.[12]
Marine
1.22
Australia’s marine environment covers 16 million square kilometres and
37 000 kilometres of coastline, including Australia’s Exclusive Economic Zone,
the continental shelf and vast oceans incorporating tropical marine to
sub-Antarctic ecosystems.[13] These ecosystems include
coral reefs, seagrass plains, kelp forests, sand-bottomed habitats, seamounts,
mangrove forests and abyssal plains.[14]
1.23
The Census of Marine Life, completed in 2010, identified that Australia
has approximately 33 000 marine species recorded in the major marine databases,
with a further estimated 17 000 species being likely to occur (as reported but
not confirmed). Of the recorded species there are:
n 58 listed as
threatened
n an unknown number
being endemic
n 8525 species of
mollusc
n 6365 species of
crustacean
n 5184 species of fish.[15]
1.24
Further, ‘[i]t is crudely estimated that there may be as many as 250 000
species (known and yet to be discovered) in the Australian EEZ [Exclusive
Economic Zone]’.[16] The Australian Marine
Sciences Association stated that ‘there is a serious underestimate of our known
marine biodiversity’, especially in northern Australia and in deeper waters.[17]
1.25
The 2011 State of the Environment report stated that knowledge of
distribution and taxonomy of Australia’s marine species remains patchy.[18]
The report gave an assessment of the overall state of marine species and
ecosystem as in good condition, with recent trends indicating that good
condition as stable, with limited evidence or limited consensus on both the
assessment grade and trend. The report further assessed a few areas,
specifically coastal places and areas on the continental shelf and upper slope,
as in very poor condition due to the effects of specific human activities. The
recent trend indicated that very poor condition as deteriorating, with limited
evidence or limited consensus on both the assessment grade and trend.[19]
Freshwater
1.26
Freshwater ecosystems incorporate, among others, lakes, swamps,
wetlands, waterways and rivers. The Australian Bureau of Statistics’ (ABS) 2009‑10
Year Book identified a likelihood of high levels of locally endemic freshwater
species, and some species with limited distribution, including crayfish,
dragonflies and mountain stream frogs.[20]
1.27
In terms of monitoring the biodiversity of freshwater ecosystems, an
example given in the 2011 State of the Environment report highlighted that
‘only 17 [per cent] of Australia has comprehensive mapping of wetlands’.[21]
The Water Resources and Freshwater Biodiversity Adaptation Research Network
also indicated that for large parts of Australia, including 75 per cent of WA:
… there is limited mapping of freshwater ecosystems or
information about freshwater system values, typology, hydrology or variability.
Even less knowledge exists about groundwater-dependent ecosystems in
Australia.’[22]
1.28
The ABS 2009‑10 Year Book also stated that many of Australia’s
aquatic [marine and freshwater] species are endemic and that ‘there are likely
to be many more aquatic species in Australia than are currently described’.[23]
1.29
The 2011 State of the Environment report assessed the state and trends
of aquatic species and ecosystems in northern and central Australia and in
southern, eastern and south-western Australia. The freshwater ecosystems in
northern and central Australia were assessed to be in good condition, with
adequate high-quality evidence and a high level of consensus on the assessment
grade. The trend was assessed as stable, with limited evidence or limited
consensus on the trend.
1.30
The southern, eastern and south-western Australian freshwater ecosystems
were assessed as being in a poor condition and deteriorating in recent trends
in areas heavily developed for agriculture. The assessment summary also
indicated that ‘information on wetlands is limited but there is good evidence
of losses and poor health of rivers in large areas of south-eastern and
south-western Australia’. There was limited evidence or limited consensus on both
assessment of the state and trend.[24]
Biodiversity hotspots
1.31
Australia is one of 17 ‘megadiverse’ countries, with 15 national
biodiversity hotspots across the continent.[25] National biodiversity
hotspots were first identified in 2003 as areas:
n that ‘support natural
ecosystems that are largely intact and where native species and communities
associated with these ecosystems are well represented’
n with high levels of
locally endemic species
n where the levels of
stress or future threat were considered to be high.[26]
1.32
The Committee visited the Tasmanian Midlands national biodiversity
hotspot and one in the south-west of WA—the Busselton‑Augusta national
biodiversity hotspot—during its site inspection program. The south-west WA
hotspot is the only one of the national hotspots to have been designated one of
34 global biodiversity hotspots.[27] Global biodiversity
hotspots must contain at least 1500 endemic species of vascular plants and must
have lost at least 70 per cent of its original habitat.[28]
1.33
The south-west of WA is a ‘flat, stable highly weathered low plateau
dominated by old landscapes with nutrient-deficient soils’, an area in which
fire plays a major role. The south-west of WA displays a number of notable
statistics:
n more than 7400 named
plant taxa and an estimated 6500 vascular flora species, with greater than 50
per cent being endemic
n approximately 20 per
cent of plant species are listed as threatened, rare or poorly known
n approximately 100
species of vertebrates are endemic
n sixty-three wetlands
of national significance are located in the region
n in 2007 there were 82
threatened ecological communities, 351 threatened plant taxa (111
critically endangered) and 69 threatened non-marine animal taxa in the region.[29]
Threats to biodiversity
1.34
There are many threats to Australia’s biodiversity, including:
n land-use practices
and changes
n grazing pressure
n habitat fragmentation
n climate change
including pollution
n invasive species
n fire regime change
n hydrology change
n consumption of
natural resources.[30]
1.35
The impacts of these threats vary across the continent, as the Committee
discovered throughout its site inspection program, with some examples given
below.
1.36
Land use poses a threat to biodiversity. Land clearing for timber
harvesting, urban expansion, mining, agriculture and tourism can impact
negatively on biodiversity. In some areas, such as the south-west of WA, there
has been extensive clearing for agricultural and urban use, creating small
pockets of remnant vegetation thereby making conservation management and
species movement difficult.[31]
1.37
Invasive species can have a devastating impact on ecosystems,
like phytophthora dieback has on native forests.[32]
The myrtle rust disease has spread on windborne spores up the east coast of
Australia, threatening to infect over 200 plant species in the wet tropics of
Queensland.[33] Invasive weeds like para
grass in the Northern Territory quickly dominate and create monocultures in the
ecosystems they invade, having the potential to alter fire regimes due to the
resultant increased fuel loads.[34]
1.38
Fire poses a threat to biodiversity, making fire management an
important land management tool for biodiversity and ecosystem protection. Fire
management in Kakadu National Park is based on Indigenous methods for burning,
hazard reduction, and for managing species, with the interrelationships being
used to protect the habitat of species that are important for ecological and
cultural reasons.[35]
Biodiversity losses
1.39
The many threats to Australia’s biodiversity have resulted in losses in
biodiversity, with more losses predicted in future. The 2011 State of the
Environment report included a number of national assessments of species, with
statistics on biodiversity losses which included:
n small mammals in
northern Australia are declining, with modern mammal extinctions having mostly
occurred in central and northern bioregions, with up to 12 taxa having been
lost
n up to 25 per cent of
known species for reptiles are threatened
n many amphibian
species have become regionally extinct in the past decade
n 90 per cent of
floodplain wetlands in the Murray-Darling Basin have been lost.[36]
1.40
The ABS reported that:
Australia has experienced the largest documented decline in
biodiversity of any continent over the past 200 years. Under the EPBC Act, more
than 50 species of Australian animals have been listed as extinct, including 27
mammal species, 23 bird species, and 4 frog species. The number of known
extinct Australian plants is 48. Australia’s rate of species decline
continues to be among the world’s highest, and is the highest in the OECD.[37]
1.41
A number of species have been declared as threatened under the Environment
Protection and Biodiversity Conservation Act 1999 (Cth) (EPBC Act); as at
March 2009 there were 1318 threatened plant species and subspecies and 402
threatened animal species and subspecies listed under the EPBC Act.[38]
1.42
In January 2010, the ABS reported on the increase in threatened species
and communities in the ten years between the introduction of the EPBC Act in
1999 to 2009:
[During this period] … the number of threatened fauna has
risen by 35%, from 315 to 426 in 2009. In 2009, almost half (47%) the species
on the list were vulnerable, 40% were endangered or critically endangered, and
13% were extinct or extinct in the wild.
Together, birds and mammals accounted for the majority of
vulnerable and endangered species, and almost half the extinct species were
mammals.
Since the commencement of the EPBC Act, the number of listed
threatened flora has risen by 15%, from 1,147 in 2000 to 1,324 in September
2009. In 2009, there were 24 eucalypt species listed as endangered and 49
listed as vulnerable. Two species of wattle were listed as extinct, three as
critically endangered, 29 as endangered and 44 as vulnerable.
The number of threatened communities rose from 21 in 2000 to
46 in 2009. However, these increases may reflect improved information and field
investigations and do not necessarily represent a change in conservation status
of ecological communities.[39]
1.43
The Australian Coral Reef Society stated in its submission that,
globally, 19 per cent of coral reefs have been lost and 35 per cent are
threatened, mostly due to human activity.[40]
1.44
The Water Resources and Freshwater Biodiversity Adaptation Research
Network stated that ‘freshwater systems have the highest rates of extinction of
any ecosystem, with estimates of at least 10 000—20 000 freshwater species
extinct or at risk’.[41]
Impacts of climate change
1.45
Climate change is expected to act as an additional stressor on
biodiversity, at the same time interacting with existing threats to exacerbate
pressure and transform ecosystems, presenting managers with novel ecosystems
and challenges.
1.46
The 2012 State of the Climate report highlighted a number of key changes
that have occurred in the climate, and the predicted impacts of those changes,
as follows:
n both natural and
human influences have affected climate over the past 100 years
n human activities have
also influenced ocean warming, sea-level rise, and temperature extremes
n it is clear that
increasing greenhouse gas concentrations will result in significant further
global warming
n further uncertainties
relate to tipping points in the climate system, such as the break-up of
ice-sheets, which can lead to rapid climate change.[42]
1.47
The Committee heard from Professor Will Steffen that climate is ‘not
just another environmental issue,’ and that:
… climate actually affects the basic physical and chemical
underpinning of life …
It changes temperature, it changes rainfall, it changes water
availability, it changes CO2 and, of course, plants are affected by that
because it is indeed a plant food and they react to that. We change the acidity
of the ocean and the land and so on. These are the very fundamental basic
underpinnings of life.
… the rate of change is unprecedented at least since the last
mass extinction event about 60 million to 65 million years ago.[43]
1.48
Changes in temperature, rainfall, extreme weather events and sea level
rise, among others, have already affected Australia’s biodiversity. The
Commonwealth Scientific and Industrial Research Organisation (CSIRO) stated, in
a terrestrial biodiversity context, that climate change is predicted to affect
almost all aspects of biodiversity conservation, as well as amplify and further
complicate the management of existing threats to biodiversity, such as those described
earlier.[44] The CSIRO also
highlighted that:
Species and ecosystems are very likely to be affected
directly by impacts cascading from individuals to populations to ecosystems and
indirectly via changes to the interactions between species, provision of
habitat, regulation of ecosystem processes and feedbacks on the climate.[45]
1.49
The National Climate Change Adaptation Research Facility (NCCARF)
Terrestrial Biodiversity Network stated that:
Australia’s biodiversity is unique and there is strong
evidence to demonstrate that negative impacts due to climate change are already
occurring across many taxonomic groups and environmental processes, and that
these impacts will continue to get significantly worse in the future.
Consequently, Australian natural ecosystems are highly vulnerable to global
climate change and it is recognised that they have a lower capacity to adapt
compared to other settings such as agricultural and urban environments … These
negative trends compound the pressures on ecosystems that are already stressed
by invasive species, habitat loss and fragmentation, fire, feral animals and
natural climate variability.[46]
Impacts on marine and freshwater biodiversity
1.50
The CSIRO stated that:
Marine, coastal and estuarine biodiversity is already, or
highly likely to be, affected by sea level rise, increased ocean storm
intensity, ocean acidification, increasing sea surface temperatures, the
southern penetration of the East Australia Current … These effects are expected
to cascade throughout food chains with flow-on effects that cannot fully be
anticipated.[47]
1.51
The CSIRO gave examples of how ‘human, land and resource use pressures
are likely to interact with climate change to exacerbate the impacts on marine
systems’:
n poor water quality
(e.g. due to terrestrial runoff at the coast) increases coral bleaching risk
n coastal development
may limit landward migration of estuarine habitats as sea levels rise
n fishing pressures may
limit the capacity of species to repopulate habitats following disturbance
events.[48]
1.52
The 2012 Marine climate change in Australia report card highlighted a
number of key changes that have already occurred in the marine environment due
to increasing sea temperatures, as follows:
n sea temperature
increases of between 2 and 4 degrees Celsius on the west coast (in early 2011),
with changes in the local abundance and distribution of seaweeds, abalone, and
fish species reported, and a shift towards a more tropical fish community
observed, providing insight to possible long-term change
n a demonstrated
southwards retreat of macroalgae (a foundation species that supports marine
life ) by 10 to 50 kilometres per decade, being likely to affect entire marine
ecosystems
n changes in sex ratios
of sea turtles, more frequent bleaching of corals, changes in abundance of fish
species, and ocean acidification leading to a potential reduction in coral
calcification
n southwards movements
of seaweeds, phytoplankton, zooplankton and some fish species have been
documented.[49]
1.53
The report card also indicated that increasing sea temperatures are likely
to impact on the distribution of marine mammals and seabirds, with species
likely to move southwards.[50] Sea level rise was
stated to be increasing at 3mm per year, which will threaten coastal systems.[51]
1.54
The Australian Institute of Marine Science stated that the trend of
increasing carbon dioxide in the atmosphere:
… means that the threat from ocean warming and acidification
to Australia’s coral reefs will grow significantly stronger over the coming
decades. Predictions are more intense coral bleaching events, more frequent
severe cyclones and declining capacity for damage repair.[52]
1.55
The Great Barrier Reef Marine Park Authority stated that climate change
is likely to be the greatest influence on the long-term outlook for the Great
Barrier Reef.[53]
1.56
The Australian Marine Sciences Association (AMSA) stated that:
… extinction risk is highest for endemic species and those
that have narrow distributional ranges … As the ocean warms, these [endemic]
species will increasingly be restricted to a smaller portion of Australian
waters, and range shifts will be limited by the southern extent of our
coastline.’[54]
1.57
AMSA also discussed how climate change will affect key physical
processes in the marine environment, as follows:
… the increased frequency and severity of catastrophic events
such as cyclones will damage marine coastal habitats impairing their function
and, in turn, impacting biodiversity. These habitats will be among the first
and most severely affected by sea level rise … Rising sea levels will affect
the distribution of wetlands and seagrasses and drown intertidal habitats which
are critical to biodiversity because of their nursery ground value and their
role in translocation of nutrients to offshore habitats. In some cases these
communities will migrate to follow rising sea levels, but in many situations
this movement will be blocked by human structures such as training walls and
roadways.[55]
1.58
In terms of climate change impacts on freshwater biodiversity, CSIRO advised
the Committee that:
Freshwater aquatic biodiversity is predicted to be altered by
climate change via direct and indirect pathways. The direct pathways that are
predicted to affect water quality and quantity are:
n changes in global air
and sea temperature are reflected in equivalent changes in water temperatures
of streams, lakes, wetlands, etc;
n an increase in air
temperature will result in increased water temperature, longer stratification
periods in reservoirs and lakes, as well as advances in spring events and
delays in autumn events;
n intensification of
coastal winds mainly due to higher cyclonic activity increase shore erosion,
alter mixing patterns, and lead to changed salinity conditions in coastal lakes
and estuaries;
n changes in
precipitation and evaporation will result in changes of hydrological cycles, river
flow regimes, sediment and nutrient transport, and can promote salinisation;
n changes of flow
regime classes due to decrease in precipitation;
n reduction of water
availability in large parts of Australia;
n sea level rise will
result in inundation of coastal freshwater ecosystems, saltwater intrusion in
coastal groundwater systems, and upstream movement of the tidal influence; and
n increased CO2
absorption will result in fresh water becoming more acidic, in some cases an
increase in phytoplankton productivity or a decrease in, for example molluscs,
is possible.
Indirect pathways by which freshwater biodiversity is
predicted to be affected include:
n levels of dissolved
oxygen tend to decrease due to increasing temperature, possibly decreasing wind
speeds, and possible increase in eutrophication
n changes in air
temperature will lead to changes in evaporation impacting mainly shallow water
bodies and wetlands by reducing water levels.
The net effect of these factors is that freshwater ecosystems
are likely to be significantly affected by climate change; however, in general
the research base here is poorer than in other environments.[56]
1.59
The Water Resources and Freshwater Biodiversity Adaptation Research
Network outlined a number of ways that freshwater ecosystems are expected to be
affected by climate change, including by changes in hydrological regime, global
warming, sea level rise, and aquatic chemistry through groundwater and
sub-surface water exchange.[57]
Variable impacts of climate change nationally
1.60
The Committee observed variations in climate change impacts across the
country, as displayed in different regions and different ecosystem types,
including terrestrial, marine and freshwater. Much of this variation is
described following observations and evidence from site inspections which
resulted in the Committee’s two interim reports:
n the decline of
woodland tree species due to hotter and drier conditions, combined with an
increased susceptibility to existing stressors such as diseases
n likely increase in
threats from pests and diseases due to projected temperature rises
n a shift in bird
ranges further south in general, and upslope in alpine areas, due to increasing
temperatures
n possibility of
alteration of sex-ratios and species decline of reptile species with
temperature-dependent sex determination due to predicted temperature rises
n loss of species
adapted to living in high altitudes due to increased temperatures
n coral bleaching of
reef ecosystems that can inhibit coral reproduction, due to increased sea temperatures
n a drying trend and
reduced groundwater levels due to changed rainfall patterns in southwest WA
n the decline in tree
species due to reduced rainfall in the Tasmanian Midlands
n the spreading of
invasive weeds into inaccessible locations due to the predicted increase in the
frequency and intensity of cyclones
n loss of bird habitats
due to inundation of roosting sites by sea level rise
n negative impacts on
the Indigenous communities of Kakadu National Park resulting from loss of
biodiversity due to climate change.
1.61
Further to the climate change impacts listed above, the Committee made
several observations relating to fire regimes and increased temperatures in
different ecosystems. Alpine ecosystems, such as in the Tasmanian Central
Plateau, have evolved largely in the absence of fire, whilst the ecosystems in
northern Australia, such as are present in Kakadu National Park, have adapted
in the presence of fire over thousands of years.
1.62
The Committee observed that inappropriate fire regimes had been
implemented in the alpine ecosystems of Tasmania, contributing to the decline
of some species (such as the miena cider gum). On the other hand, the Committee
noted that fire management in Kakadu National Park was based on traditional
Indigenous fire burning methods, hazard reduction, and for managing species (as
noted above). In both cases, the Committee noted the importance of fire
management for ecological and safety reasons, as well as for cultural reasons
in the ecosystems of Kakadu National Park.[58]
1.63
In terms of variable impacts arising from increased temperatures, the
Committee observed the impacts of species decline in alpine regions as compared
to wet tropical regions. In the NSW Snowy Mountains region the Committee heard
about the potential for loss of species adapted to living in high altitude
conditions due to small increases in the average temperature. In the wet tropics
of Queensland region, the Committee heard about the decline in numbers of the
endemic lemuroid ringtail possum, partly due to an extreme, extended heat wave
experienced in the region in 2005.
1.64
In the NSW Snowy Mountains region, the Committee noted the complexity of
interactions taking place in the alpine environment in response to climate
change, and that precise outcomes for individual species were difficult to
predict but that some species would be threatened with extinction. The
Committee also observed changes to the level of the alpine tree line due to
increasing temperatures. In the wet tropics of Queensland, the Committee noted
the potential for species adapted to living in high altitude conditions having
to move to higher altitudes to survive.[59]
1.65
Having assessed in this chapter the state of Australia’s biodiversity,
the threats to biodiversity and biodiversity losses, and the variable impacts of
climate change, the Committee will, in the next chapter, discuss the effects of
biodiversity loss on human communities.