Plant and animal species

2011

 

Species diversity is a key component of biodiversity. In this subsection, we review what general conclusions can be drawn about the state and trends of specific groups of animal and plant species at national and subnational scales.

Threatened species lists

Each Australian state and territory has a legislated process for listing species as threatened (with categories such as rare, vulnerable, endangered and extinct) if the size and trend in populations and the pressures that the species face satisfy certain scientifically established criteria. Some jurisdictions also have the capacity to list threatened ecological communities. SoE reports usually report total numbers of species listed as threatened (Figure 8.4) as well as changes since previous reports.

Changes in numbers of listed species must be interpreted with care, because they are only partly due to declines or improvements in the status of species. Often they are due more to the effort put into collecting information, the groups of organisms that are focused on in a particular period and reviews of listed species (conducted by the Australian and state and territory governments), as well as differences in how species are listed by different jurisdictions. A recent analysis of taxa listed under the EPBC Act found that the formal status of 75 nationally listed flora taxa and 44 fauna taxa changed between 2002 and 2007.15 It was concluded that about 46% of these changes occurred because of improved knowledge and 36% were due to taxonomic updates. Real change attributed to decline accounted for 21.3% of flora taxa and 52.3% of fauna taxa. There were no cases of real improvement in the status of listed taxa at the national level.

Another consideration when interpreting total numbers of threatened species is that they partly reflect the overall number of species in a group (e.g. there are many threatened plants but also many species of plants) and so numbers of threatened species should be considered in relation to total numbers of known species. This is done wherever possible in the following sections.

Figure 8.5 shows the geographic distribution of all terrestrial species listed as threatened under the EPBC Act. The highest numbers occur down the east coast and in the south-west of Western Australia. As will be discussed in Section 3, these areas represent areas of high historical and current pressures.

As well as the Australian continent, the Australian external territories should also be mentioned: although these territories comprise a small proportion of Australia by area, they include some unique environments. The territories include Christmas Island, Norfolk Island, Cocos (Keeling) Islands, Heard Island and McDonald Islands, Ashmore and Cartier Islands, Coral Sea Islands, the Australian Antarctic Territory and some Indian Ocean territories.80 We have been unable to compile detailed information on the state of biodiversity in each of these territories (some aspects are covered in other chapters, including Chapter 6: Marine environment and Chapter 7: Antarctic environment). The Director of National Parks reported on the state of national parks on three external territories in 2009–10 (Table 8.9).

Table 8.9 Summary of species listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999 in national parks in three Australian external territories in 2009–10
Territory Fauna Flora Total species recorded
Pulu Keeling National Park 1 critically endangered
4 endangered
5 vulnerable
24 migratory
36 marine
None 5 mammals
24 birds
6 reptiles
31 plants
Christmas Island National Park 2 extinct
1 critically endangered
4 endangered
7 vulnerable
63 migratory
92 marine
2 critically endangered
1 endangered
3 mammals
95 birds
9 reptiles
More than 2000 invertebrates
213 plants
Norfolk Island National Park and Botanic Garden 5 extinct
5 critically endangered
2 endangered
5 vulnerable
37 migratory
57 marine
15 critically endangered
16 endangered
15 vulnerable
2 mammals
50 birds
2 reptiles
180 plants

Source: Australian Government Department of Sustainability, Environment, Water, Population and Communities81

2.4.2 Plant species

Although information on state and trends for some plant species in some parts of Australia is good, most jurisdictions report that survey information overall is inadequate to establish recent trends (Table 8.10). For example, in New South Wales, where gaps in information have been particularly well documented, no data are available for 73% of threatened plant species, let alone other plant species.35 Especially in areas of high species diversity, new species are still being discovered or described. In Queensland, for example, more than 50 previously unknown plant species are being described every year.40

Table 8.10 Summary of assessments of terrestrial plant species in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State and trend
ACT Continued decline in woodlands and grasslands
NSW Status is variable among plant groups and the overall trend is unknown
Plant species diversity has declined significantly since settlement, but there are limited suitable data to quantify the rate or magnitude of decline. Since European settlement, 35 plant species have become extinct
NT The government website lists 65 species of plants as threatened
Qld There are 428 plant species listed as threatened. Numbers have generally increased but are highly variable between bioregions
SA The number of threatened plant species is increasing. In 2007, 187 plant species were listed as presumed extinct, endangered and critically endangered, and 196 were listed as vulnerable (around 7% of known plant species in the state)
Tas Trend is unknown but probably declining. There are 270 forest-associated vascular plant species considered to be at risk from isolation and loss of genetic diversity. Species listed as threatened in 1995, 2000 and 2007 were 465, 460 and 487, respectively
Vic Of 3140 known species of vascular plants, 1826 (58%) are included on the Advisory List of Rare and Threatened Plants, of which 49 are considered extinct, while only 288 are listed under the Flora and Fauna Guarantee Act 1988. In 2007 (compared to 2002), 20 bioregions had more threatened species, 4 had the same number and 4 had fewer
WA The number of threatened and priority taxa increased by 14% between 1998 and 2007 (from 2309 to 2625 taxa)
National The proportion of threatened taxa is up to around 30% of total taxa for vascular plants in the best surveyed regions

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

Figure 8.6 shows the proportion of EPBC-listed plant species in Interim Biogeographic Regionalisation of Australia (IBRA) bioregions. Given the limitations on listing data discussed above, it is unwise to draw detailed inferences from this figure. The general trend is for higher proportions of plants to be threatened along the east coast and Cape York, and in the south-west. While the maximum proportion shown in this figure is 15.1%, higher proportions are reported for state and territory-listed species (up to around 30% in the best surveyed bioregions).15 In Victoria, where some of the greatest survey effort has been made, it is reported that 58% of all known plants are either threatened or under assessment for listing (Table 8.10). Different patterns between national and jurisdictional listings are not unexpected, because some species can be threatened in one state or territory but not nationally (because they are secure in other states or territories).

Fungi and other nonplant, nonanimal species

Very few data are reported by any jurisdiction on fungi or other species not classified as plants or animals (Table 8.11). This is a major data gap, because many of these species, especially fungi, play vital roles in ecological processes such as the distribution of carbon and nutrients throughout plant–soil systems. Although the evidence is limited, it is highly likely that native fungal species are declining in cleared landscapes and being replaced by introduced species in many areas.82

Table 8.11 Summary of assessments of fungi and other nonplant, nonanimal species in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State (and trend if reported)
ACT The new plant list for the ACT, when published, is expected to include cryptogams (fungi) (about 600 species), lichens (about 405 species), liverworts and hornworts (about 107 species) and mosses (about 208 species)
NSW There are an estimated 30 000 species of fungi in NSW. Nine communities are listed as threatened. Of an unknown number of aquatic and terrestrial algae, 2 are listed as threatened
NT No information on website
Qld No mention in report
SA No mention in report (sampling and curating of fungi has been progressing but data are not available electronically)
Tas Ecological importance is recognised in report but no assessment is given
Vic Of an unknown number of fungi, nonvascular plants and lichens, 146 were included on the Victorian Advisory List, 2 of which are considered extinct, while 15 are listed under the Flora and Fauna Guarantee Act 1988
WA Noted in the report as being poorly understood
National Fungi are the most diverse group of organisms apart from the insects. Australia is estimated to have 160 000–250 000 fungal species, of which less than 5% have been described. There appear to be no fungi listed as threatened nationally under the Environment Protection and Biodiversity Conservation Act 1999

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

2.4.4 Animal species overall

Recent SoE reports from around Australia, as well as previous national reports for over a decade, have expressed moderate to high levels of concern about a decline in many groups of fauna in their jurisdictions, although frequently it is acknowledged that data are inadequate to draw firm conclusions about which groups are declining and by how much. Many of the concerns are based on the pressures that exist and the known effects of these pressures on biota, rather than reliable data on the distribution and abundance of the species themselves.

The state and territory SoE reports reviewed in the following sections, together with the recent national assessment of Australia's terrestrial biodiversity,15 conclude that data on species of animals around Australia are very limited for most groups in most jurisdictions. In many cases, it is not possible to draw conclusions about trends in the state of animal species groups and sometimes it is not even possible to draw confident conclusions about the state of the taxon itself. The most recent New South Wales SoE report presented this lack of data very clearly (Figure 8.7).

Mammals

Mammals have been the best studied group of animals and major extinctions since European settlement have been documented. Assessments from state and territory SoE reports are summarised in Table 8.12. Excluding extinct species, it is estimated that in many subregions of Australia, more than 15% of known mammal species are listed as threatened nationally, and in many this proportion is 25–50% (Figure 8.8).

Table 8.12 Summary of assessments of mammals in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State (and trend if reported)
ACT Numbers of some kangaroos are growing to problematic levels. Since 2003, one new mammal species has been listed as vulnerable or endangered
NSW Mammals have experienced the greatest rate of extinction among flora and fauna since European settlement (26 of 138 species [19%] now extinct). A further 10% of species (18% of those assessable) have lost at least half their distribution. Curently, 1% of species is considered at high risk of being unsustainable, another 1% to be at moderate risk, 3% at low risk and 76% had no data available. A general pattern of decline over the longer term is evident, although some species have flourished
NT 14 species are listed as extinct, 1 as extinct in the wild, and 23 as threatened
There have been reports of major declines in numbers of small mammals
Qld Around 70% of Australia’s native mammals (210 species) live in the state; 38 species are listed as threatened
Assessments of trends are based on a few target species and are variable; northern hairy-nosed wombats appear to be recovering while koalas have declined in some areas
SA At least 28 species have become extinct since European settlement
Currently, 47 species are listed an endangered and 20 as vulnerable (together, 38% of the total known)
Tas The most ecologically diverse group of large marsupial carnivores in Australia occur in the state. Among selected species, some populations are increasing, some are declining and some are stable
5 forest-dwelling species have been assessed as being at risk from loss of genetic diversity
Vic 18 species are listed as extinct
The Advisory List of Threatened Vertebrate Fauna lists 41 extant species compared with 34 listed under the Flora and Fauna Guarantee Act 1988
WA Medium-sized mammals have undergone considerable decline in the north-west; of an estimated total of 220 mammal species, 11 are presumed extinct and 42 are listed as threatened
National There is accumulating evidence of a decline in small mammals in northern Australia. Almost every bioregion of Australia contains numerous threatened taxa. Threatened taxa range up to around 60% for mammals in the best surveyed regions
Modern mammal extinctions have mostly occurred in central and northern bioregions, with losses of up to 12 taxa recorded

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

For EPBC-listed mammals, the highest proportions of threatened to total species occur throughout central Australia, in Western Australia and in the south and south-west of the continent.15 A broadly similar pattern is seen for mammal species listed as threatened in states and territories, but the proportions in most subregions are greater than 15% and the highest proportions range up to around 70%.

Recent reports of major declines in mammals in northern Australia, where it had previously been assumed that impacts of humans were less, were unexpected and are raising concerns among ecologists (Box 8.3).

Box 8.3 Into oblivion? The disappearing mammals of northern Australia

Since European settlement, the greatest loss of Australian biodiversity has been the spate of extinctions of endemic mammals. Historically, these losses occurred mostly in inland and temperate parts of the country, and largely between 1890 and 1950. A new wave of extinctions is now threatening Australian mammals in northern Australia. Many mammal species are in sharp decline across the north, even in extensive natural areas managed primarily for conservation. The main evidence of this decline comes consistently from two contrasting sources: robust scientific monitoring programs and more broadscale Indigenous knowledge.

The main drivers of the mammal decline in northern Australia include inappropriate fire regimes and predation by feral cats. Cane toads are also implicated, particularly in the recent catastrophic decline of the northern quoll. Some impacts are due to vegetation changes associated with the pastoral industry. Disease could also be a factor, but there is little evidence for or against it.

Based on current trends, many native mammals will become extinct in northern Australia in the next 10–20 years, and even the largest and most iconic national parks in northern Australia will lose native mammal species. This problem needs to be solved. The first step towards a solution is to recognise the problem, and this report seeks to alert the Australian community and decision-makers to this urgent issue. Targeted management of known threats, based on the evidence currently available, is urgently required to ensure the survival of northern Australian mammal species. In part, the answer lies in more rigour and accountability in the management of conservation reserves, but it also lies in seeking to identify and deliver more conservation outcomes from all other areas. In the shorter term, strengthening the safeguards on islands off northern Australia would enable their use as a temporary refuge for ‘at risk’ species until a more comprehensive solution can be reached on the mainland.

Source: Fitzsimons83

Birds

The status of birds, and the information available to establish that status, is highly variable between different parts of Australia (Table 8.13). Threatened taxa range up to 30% for birds in the best surveyed regions. At least part of this variation might be due to differences in survey effort, which has been greater in the south and centre of the country and in the Northern Territory.15

On a statewide scale, the proportions of known bird species considered to be threatened in South Australia and New South Wales are 34% and 25%, respectively (Figure 8.9). In Victoria, 17% are listed as threatened under the formal state-listing process, but an additional 11% are included on the advisory list of species under consideration. In Queensland, which claims to be home to 80% of Australia's bird species, 6% are listed as threatened but there are concerns that the legacy of past loss of habitat might not yet be fully evident.40 In Western Australia, 7% of bird species are listed as threatened.

Table 8.13 Summary of assessments of birds in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State (and trend if reported)
ACT There are large fluctuations in different species partly due to habitat changes after 2003 bushfires and prolonged drought, and possible declines in some woodland species
NSW Historical data show that birds have been relatively resilient to declines compared with other vertebrate groups; however, over the shorter timeframe of the past decade, the distribution of many birds has declined and the prospects for sustainability of many species are at risk. Status is given as poor. Of 452 known species, 126 species or populations are listed as threatened (28% of the total or 25% if the 12 extinct species are excluded). Of the total species, 2% are presumed to be extinct, 4% in severe decline, 7% in moderate decline, 40% in no significant decline and no data are available for the other 47%. There are adequate data to assess future sustainability for around half of all known species, but only 16% are considered sustainable or at low risk of being unsustainable—the rest being at moderate to severe risk or extinct
NT 19 species are listed as threatened and 1 is regarded as extinct
Qld Around 80% of Australia’s bird species (594) live in the state; 35 species are listed as threatened. There are concerns that for some long-lived bird species there is a timelag between loss of habitat and consequent loss of species, a process that has been referred to as ‘extinction debt’
SA 42 species are listed as endangered and 32 as vulnerable (together, 16% of all recorded species); and 7 species are reported to have become extinct
Tas Few general conclusions are possible due to high variability of populations and limited long-term data sets
Vic There are concerns about declines in forest and woodland birds where these habitats have been disturbed. Of 447 total recorded species, 126 are included on the Advisory List of Threatened Vertebrate Fauna (versus 78 listed under the Flora and Fauna Guarantee Act 1988)d
WA Of 611 species recorded, 45 are listed as threatened and 2 are extinct
National Mammals and birds account for the high numbers of threatened species in central and northern Australia. Threatened taxa range up to around 30% for birds in the best surveyed regions. Threatened birds occur in high numbers along the east coast, in Vic and SA, in the centre of the continent and in the south-west of WA

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

Birds Australia produces regular national assessments of the state of Australia’s birds, using methods for surveying the presence or absence of birds that can be used by volunteers and that are amenable to rigorous statistical analysis.84 The 2008 report, The state of Australia’s birds, presented the results of around 50 continuous monitoring studies of birds undertaken from as early as 1967.85 It reported both favourable and unfavourable conclusions.

Favourable conclusions included the following:

  • Knowledge of long-term patterns and trends in bird populations is improving.
  • Of the 18 threatened taxa with long-term monitoring programs, the populations of 4 have increased, 2 are more or less stable and 12 have decreased.
  • Numbers of Gould’s petrel, glossy black cockatoo, superb parrot and Tasman parrot have all increased since their monitoring programs and management began, while populations of the orange-bellied parrot and Lord Howe Island woodhen have stayed about the same.
  • Interventions to address key pressures is improving the status of threatened and nonthreatened species (see Section 3).

Unfavourable conclusions included the following:

  • Since 2003, observed numbers of common and widespread birds have sharply declined, most notably across the Murray–Darling Basin.
  • Studies point to major change in Australia’s bird communities, with many species declining (those of woodland, forest, grassland, heathland and wetland habitats) and a very few increasing (e.g. larger more aggressive honeyeaters).
  • A number of robins, thornbills, fantails, shrike-thrushes, treecreepers and other small insectivores, particularly those that feed on or near the ground, are decreasing in various south-east woodlands.
  • At least two intercontinental migrants show steeply declining trends at all sites reported on and a third is of concern. Numbers of eastern Australian waterbirds in general, and some resident shorebirds in particular, have fallen significantly.
  • Gaps in monitoring include forest and island birds, both of which are suspected or predicted to be suffering declines. Studies are only just beginning to track changes in birds (particularly seed-eaters) of the tropical savannas and uplands. The arid and semi-arid zones are also poorly covered.
  • Apart from the studies reported on by Birds Australia, monitoring is generally piecemeal and too short term to detect meaningful trends in bird populations.

Freshwater fish

Freshwater fish are discussed in detail in Chapter 4: Inland water. For comparison with other groups in this section, Table 8.14 summarises what jurisdictional reports have said about freshwater fish.

Table 8.14 Summary of assessments of freshwater fisha in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmentb
Jurisdiction State (and trend if reported)
ACT Significant threats to survival of local populations of some threatened fish species remain
NSW Of 55 known species of freshwater fish, 12 are listed as threatened
NT 8 river-dwelling fish species are listed as threatened
Qld 6 species of fish are listed as threatened
SA Freshwater fish are included in broader biodiversity assessment and not discussed separately
Tas Freshwater fish are the most threatened group in inland waters. Several species are listed as threatened in the last state of the environment reporting period bringing the total listed to 11 of the 25 Tasmanian native species
Vic 21 freshwater and estuarine fish species are considered to be threatened
WA Marine and aquatic biodiversity is generally less well known and described than terrestrial taxa, and the lack of knowledge remains a significant shortcoming
National In the Sustainable Rivers Audit of the Murray–Darling Basin, native fish species were found in only 43% of valley zones where they were predicted to occur under reference condition, indicating a decline of native fish in the Basin. The Lake Eyre Basin (LEB) Rivers Assessment found the rivers and catchments of the LEB to be in generally good condition, with critical aquatic ecosystem processes remaining intact

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See also Chapter 4: Inland water

b See notes below Table 8.5 for caveats and sources

Reptiles and amphibians

Data on the state of reptiles and amphibians are extremely variable across Australia. The combination of sightings, survey efforts and knowledge about pressures has led to the expression of general concern about many species in these groups in SoE reports from most jurisdictions (Table 8.15). This is especially true of species that live in native grasslands and woodlands.

Table 8.15 Summary of assessments of reptiles and amphibians in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State (and trend if reported)
Reptiles
ACT There is a continued decline in species reliant on woodland and grassland
NSW Of the 230 known species, 42 (18%) are listed as threatened, of which 1 is listed as presumed extinct
8% of all reptile species are assessed as in severe decline, 14% as in moderate decline, 21% as in no significant decline and no data are available for the other 57%
There are inadequate data to assess the sustainability of over 99% of species
NT 11 species are listed as threatened
Qld A little over half of Australia’s reptile species (429) live in the state; 21 are listed as threatened
SA 9 species are listed as endangered and another 9 as vulnerable (together 8% of the total known)
Tas No assessment is reported
Vic Declines are noted, especially in some disturbed forests; of 133 known species, 49 are on the Advisory List of Threatened Vertebrate Fauna, of which none are listed as extinct, while 29 are listed under the Flora and Fauna Guarantee Act 1988
WA Of 510 known species, 23 are listed as threatened (none as extinct)
National Threatened taxa range up to around 25% of known species for reptiles in the best surveyed regions
Amphibians
ACT There is a decline in records, probably due to drought
NSW Of 83 known species, 28 (34%) are listed as threatened, none of which are considered extinct
10% of all species are considered to be in severe decline, 7% in moderate decline, 28% in no significant decline and no data are available for 55%
Data are inadequate to assess future sustainability for over 96% of species
NT Only 1 species is listed as threatened (vulnerable)
Qld Around half of Australia’s frog species (114) live in the state; 25 are listed as threatened
SA No species are listed as endangered, but 4 are listed as vulnerable (15% of total recorded); a further 2 are extinct
Tas Few data are available, but there is concern about effects of drought and fungal infections
Vic Of 33 known species, 17 are included on the Advisory List of Threatened Vertebrate Fauna, none of which are considered extinct
WA Of 77 recorded species, 3 are listed as threatened
National Amphibians are represented in relatively low numbers in all jurisdictions; many have become regionally extinct in the past decade

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

In those states that have reported proportions of known species that are listed as threatened or are of concern (i.e. New South Wales, Queensland, Victoria and Western Australia) the estimates range widely and some are very high (i.e. 5–37% for reptiles and 4–52% for amphibians) (Table 8.15).

Invertebrates

Despite their importance in many ecological processes like carbon and nutrient cycling in soils, pest control and pollination,63,67 there has been very limited assessment of the state of invertebrate species and populations across most of Australia (Table 8.16).

Table 8.16 Summary of assessments of invertebrates in state and territory state of the environment reports and the most recent national terrestrial biodiversity assessmenta
Jurisdiction State (and trend if reported)
ACT Some research is under way but no data are presented
NSW Of an unknown total number of species, 19 species and 2 populations are listed as threatened
NT 35 species (mostly snails) are listed as threatened
Qld Invertebrates are not mentioned in the report
SA Invertebrates are mentioned but not specifically reported on
Tas The state has an estimated 35 000 nonmarine invertebrate species; approximately one-third are endemic
119 species listed as threatened, including some beetles, butterflies, moths, snails, spiders and crayfish
Vic Knowledge of the status of invertebrates is extremely poor
WA Poorly understood in general. Many species are threatened by changes to plant communities caused by Phytophthora dieback
Stirling Range trapdoor spiders and Kimberley land snails are threatened by too much fire
National The counts for invertebrates are patchy, reflecting the lower intensity of survey for invertebrates relative to other taxonomic groups

ACT = Australian Capital Territory; NSW = New South Wales; NT = Northern Territory; Qld = Queensland; SA = South Australia; Tas = Tasmania; Vic = Victoria; WA = Western Australia

a See notes below Table 8.5 for caveats and sources

Cork S (2011). Biodiversity: Plant and animal species. In: Australia state of the environment 2011, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/science/soe/2011-report/8-biodiversity/2-state-and-trends/2-4-plant-and-animal-species, DOI 10.4226/94/58b65ac828812