Biodiversity

Gang-Gang Cockatoo. Source: Ryan Colley

This section provides an assessment of biodiversity in the ACT, including threatened and important species, conservation of ecosystems and species, native vegetation, and invasive plants and animals.

Key findings

52 species and 3 ecological communities are listed as threatened in the ACT

141,000 hectares have conservation status in the ACT, protecting 60% of the total ACT area

70% of woodland, grassland and open forest communities are outside conservation areas

Chronic degradation of habitat condition, mainly in fragmented landscapes, is a significant problem in the ACT.

Background

Biodiversity is the variety of life. This can include the diversity of genes within a species, the diversity of species within a landscape and the diversity of ecosystems across landscapes. It can also include the diversity of ecological processes that underpin the functioning of ecosystems such as seed dispersal, pollination and nutrient cycling.

Healthy biodiversity is essential to the natural world and fundamental to human life. The complex and dynamic interactions between plants, animals, microorganisms and soil, water and air underpin the health of the ecosystems. Whilst biodiversity is dependent on good ecosystem health, biodiversity itself plays a pivotal role in maintaining ecosystems. Biodiversity loss or decline can have significant consequences for natural processes, decrease the availability of habitat, and impact on predator–prey relationships. In severe cases, biodiversity loss can lead to significant changes in ecosystems and the functions they provide. 

Biodiversity may also make ecosystems more resilient to pressures such as climate change and fire. A diversity of species and ecological processes can help ecosystems to maintain their core functions in the face of environmental change. 

The complex and dynamic interactions between plants, animals, microorganisms and soil, water and air underpin the health of the ecosystems.

Because terrestrial ecosystems are intimately connected to aquatic ecosystems, their degradation has consequences for the condition of the ACT’s rivers, lakes, and wetlands. 

Healthy ecosystems, biodiversity and land provide a range of benefits to human wellbeing, including climate regulation, clean air and water, nutrient cycling, pollination, control of pests, carbon sequestration, and the supply of foods and fibres. It is important to maintain and, where necessary, improve the health of ecosystems to ensure the continued availability of the services they provide.

Pressures on biodiversity

The main pressures on biodiversity in the ACT are land use change (particularly greenfield development), climate change, invasive plants and animals, vegetation loss, habitat fragmentation and changes to fire regimes. The use of chemicals such as pesticides can also have significant impacts on biodiversity, especially insects. 

Climate change is predicted to compound existing pressures on biodiversity. Projections of significant shifts in local climates and increases in drought, bushfires and storms, will have an impact on biodiversity and natural ecosystems. 

Climate change is likely to impact species with limited capacity to migrate, such as those restricted to particular habitats and fragmented landscapes, or those that tolerate only narrow ranges of temperature and rainfall. Species dependent on wetland and mountainous ecosystems have been identified as being at greatest risk. Climate change will exacerbate current environmental pressures; therefore the capacity of natural ecosystems to adapt to climate change will improve if existing threats are addressed.

Key actions

That the ACT Government:

Yellow-tailed black cockatoo. Source: Ryan Colley
Yellow-tailed black cockatoo. Source: Ryan Colley
Action 1

increase the protection of mature and hollow-bearing trees to maintain critical habitat.

Action 2

continue monitoring to evaluate the effectiveness of environmental offset conservation outcomes and the condition of conservation areas.

Action 3

increase the representation of the threatened Natural Temperate Grasslands and Yellow Box/ Red Gum Grassy Woodland communities in conservation areas, and improve protection for
all grassland and open forest communities to support threatened species dependent on these ecosystems.

Action 4

improve knowledge on changes in vegetation extent from land use change and chronic degradation such as dieback.

Action 5

continue revegetation programs to improve native vegetation extent and connectivity.

Action 6

improve knowledge on vegetation condition across the ACT.

Action 7

ensure tolerable fire intervals are considered in prescribed burn decision frameworks.

Action 8

continue to undertake invasive and pest species management and ongoing control to minimise the impacts of established populations and to eradicate new outbreaks.

Action 9

improve funding and resourcing for biodiversity management on private land, and provide incentives to rural landholders to protect paddock trees.

Action 10

improve funding for citizen science groups that significantly contribute to the ACT’s biodiversity knowledge.

See all actions →

Indicator dashboards

B1: Threatened species and ecological communities

As at 2019, there were 7 critically endangered species, 18 endangered species, 26 vulnerable species and one regionally conservation dependent species in the ACT. Over the reporting period (2015–16 to 2018–19), 17 additional species were listed as threatened and 7 species were transferred to critically endangered to align with their Commonwealth status. There are 3 ecological communities classed as endangered, with High Country Bogs and Associated Fens added during the reporting period. In addition, ‘the loss of mature native trees (including hollow-bearing trees) and a lack of recruitment’ was listed as a key threatening process. While changes in listings do not necessarily represent a decline, it is clear that the future of some species and communities in the ACT are threatened without management intervention.

Condition & trend
  • ? Poor
  • ? Fair
  • ? Good
Data quality
High
B2a: Extent of conservation areas

Extent: Conservation areas protect 60% of the total ACT area and continue to increase as environmental offsets are added to the Canberra Nature Park network.

Condition & trend
  • Trending arrow Poor
  • Trending arrow Fair
  • Trending arrow Good
Data quality
High
B2b: Condition of conservation areas

Condition: At the time of reporting, it was not possible to determine the condition of conservation areas in the ACT. It is also not currently possible to assess whether offsets have ensured no net loss of biodiversity as a result of land development. However, assessments for offsets will likely take many years. Recently initiated monitoring programs will greatly improve condition knowledge in the future.

Condition & trend
  • ? Poor
  • ? Unknown
  • ? Good
Data quality
Low
B3: Representation of threatened species and ecological communities in conservation areas

While many of the ACT’s threatened species and ecological communities are well represented in conservation areas, some flora and fauna species and ecological communities remain poorly represented. This is particularly the case for Natural Temperate Grassland and Yellow Box/Red Gum Grassy Woodland. For species with large proportions of non-reserved habitat, this is due to their dependence on grassland and woodland habitats, which are not as well protected in conservation areas as other ecosystems (such as forests).

Condition & trend
  • Trending arrow Poor
  • Trending arrow Fair
  • Trending arrow Good
Data quality
Moderate
B4a: Extent of native vegetation

Extent: Due to the large area of conservation reserves, the ACT has extensive areas of native vegetation. Any recent native vegetation losses are estimated to be small and mainly due to changes in land use from urban development. There have also been substantial revegetation efforts to restore habitat and connectivity.

Condition & trend
  • Trending arrow Poor
  • Trending arrow Fair
  • Trending arrow Good
Data quality
Moderate
B4b: Condition of native vegetation

Condition: It was not possible to determine an overall assessment of vegetation condition for the ACT, or changes over the reporting period (2015–16 to 2018–19). Available condition assessments show an increased occurrence of dieback in the ACT, large areas of poor riparian connectivity, much vegetation outside tolerable fire intervals and vegetation dominated by early and young growth stages. However, woodlands, Natural Temperate Grasslands and secondary grasslands have shown an increase in native plant species richness suggesting an improvement in condition.

Condition & trend
  • ? Poor
  • ? Fair
  • ? Good
Data quality
Low
B5: Distribution and abundance of terrestrial plants and animals

Invasive plants and animals continue to have a significant impact on native species and ecosystem health, and also represent a significant management burden. In areas where invasive species are controlled, outcomes clearly demonstrate the value of well-resourced and ongoing invasive species management to control established populations and to eradicate new outbreaks where possible.

Condition & trend
  • Poor
  • Fair
  • Good
Data quality
Moderate
Indicator assessment legend
Condition
  • Poor
  • Fair
  • Good

Environmental condition is healthy across the ACT, OR pressure likely to have negligible impact on environmental condition/human health.

  • Poor
  • Fair
  • Good

Environmental condition is neither positive or negative and may be variable across the ACT, OR pressure likely to have limited impact on environmental condition/human health.

  • Poor
  • Fair
  • Good

Environmental condition is under significant stress, OR pressure likely to have significant impact on environmental condition/ human health.

  • Poor
  • Unknown
  • Good

Data is insufficient to make an assessment of status and trends.

Trend
Trending arrow

Improving

Trending arrow

Deteriorating

Stable

?

Unclear

Data quality
High

Adequate high-quality evidence and high level of consensus

Moderate

Limited evidence or limited consensus

Low

Evidence and consensus too low to make an assessment

N/A

Assessments of status, trends and data quality are not appropriate for the indicator

Data summaries

Threatened species and ecological communities

As at 2019, a total of 52 species of fauna and flora across all habitats (terrestrial and aquatic) were listed as threatened under the Nature Conservation Act 2014.

These species include 7 critically endangered, 18 endangered, 26 vulnerable and 1 regionally conservation dependent.
During the reporting period (2015–16 to 2018–19), 17 additional species were listed as threatened and 7 species were transferred to critically endangered to align with their Commonwealth status.

Critically endangered species include the Regent Honeyeater (Anthochaera phrygia), Swift Parrot (Lathamus discolor), Northern Corroboree Frog (Pseudophryne pengilleyi), the locally extinct Yellow-spotted Bell Frog (Litoria castanea), Canberra Spider Orchid (Caladenia actensis), Brindabella Midge Orchid (Corunastylis ectopa), and the Kiandra Greenhood (Pterostylis oreophila).

Action plans and/or conservation advice have been developed for all species listed as threatened in the ACT.
Three ecological communities are listed as endangered. These are Natural Temperate Grassland, Yellow Box/ Red Gum Grassy Woodland, and High Country Bogs and Associated Fens which was added to the endangered category in 2019.

In 2018, ‘the loss of mature native trees (including hollow-bearing trees) and a lack of recruitment’ was listed as a key threatening process in the ACT, adversely affecting 4 vulnerable bird species including the Superb Parrot (Polytelis swainsonii), Brown Treecreeper (Climacteris picumnus), Glossy Black Cockatoo (Calyptorhynchus lathami) and Little Eagle (Hieraaetus morphnoides).

Conservation: extent of conservation areas

In 2019, 141,000 hectares have conservation status in the ACT, protecting 60% of the total ACT area. This not only represents a significant proportion of the ACT’s natural environment, but is also a much higher proportion than any other jurisdiction in Australia.

The Namadgi National Park and Bimberi Wilderness Area account for nearly 80% of the conservation area and around 46% of the total area of the ACT. Nature reserves (including Canberra Nature Park) account for 14% of the conservation estate, with water supply and special purpose reserves accounting for 5% and 3% respectively.
Over the reporting period (2015–16 to 2018–19), just over 1,000 hectares were added to the reserve system, primarily through environmental offsets added to the Canberra Nature Park network.
The area of environmental offsets has grown from 18 hectares in 2009 to 1,865 hectares in 23 offset areas in 2019.
This increase reflects the need to compensate for adverse environmental impacts from the significant increase in the ACT’s urban footprint that has taken place since 2000, and continues today.
In 2019, 47% (871 hectares) of offsets were protected by nature reserve. Environmental offsets now contribute to around 16% of the ACT’s urban and peri-urban reserve areas.
Outside of protected areas, progress in conservation of biodiversity, including both habitats and species, remains a challenge.
Although conservation areas provide protection by excluding damaging land uses and activities, they are still at risk from a range of pressures. Invasive species, inappropriate fire regimes, pathogens and diseases can all threaten ecosystem health and require ongoing intervention to minimise impacts.
Conservation: condition of conservation areas
At the time of reporting, it was not possible to determine the condition of conservation areas in the ACT.
It is also not currently possible to assess whether offsets have ensured no net loss of biodiversity following land development. However, assessments for offsets will likely take many years, particularly given that management interventions need to be undertaken over long periods of time to effect the desired ecosystem and biodiversity outcomes.
The ACT Government is implementing a Conservation Effectiveness Monitoring Program to evaluate the effectiveness of management actions in achieving conservation outcomes. This will greatly improve knowledge of conditions in the future.
Climate change will threaten conservation areas, especially where changes to temperature and rainfall, and the occurrence of fire, exceed the tolerances of ecosystems.
Representation of threatened fauna in conservation areas

The Broad-toothed Rat, Greater Glider, Northern Corroboree Frog, and Smoky Mouse threatened species have all, or close to all, of their known and potential habitat in ACT conservation areas.

Other threatened fauna with significant proportions of their known and potential habitat in ACT conservation areas include the Pink-tailed Worm-lizard (80%) and Spotted-tailed Quoll (70%).

Threatened fauna with less than 50% of their known and potential habitat in ACT conservation areas include the Perunga Grasshopper (47%), Golden Sun Moth (44%), Striped Legless Lizard (33%), and Grassland Earless Dragon (25%). However, these species have a substantial proportion of their habitat on national land (between 20% and 50%) and are subject to management as required under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

The Grey-headed Flying Fox does not have habitat in ACT conservation areas but there are colonies occurring in Commonwealth Park (national land) and at Lake Ginninderra (urban open space).
Threatened species with substantial proportions of their known and potential habitat on non-reserved land (outside both ACT reserved and national lands) include the Pink-tailed Worm-lizard (20%), Spotted-tailed Quoll (27%), Golden Sun Moth (28%), Perunga Grasshopper (32%), and the Grassland Earless Dragon (33%). Of particular concern is the lack of reserved habitat for the Striped Legless Lizard with 46% of habitat not reserved.
For species with large proportions of non-reserved habitat, this is due to their dependence on grassland and woodland habitats which are not as well protected in conservation areas as other ecosystems such as forests.
All of the ACT-listed aquatic species have around 90% to 100% of their potential distribution in conservation areas.
Representation of threatened flora in conservation areas

Over half of the known threatened plant sites in the ACT are located in reserves or on other land managed by the ACT Parks and Conservation Service (PCS). An additional 20% occur on national land, which is managed by the National Capital Authority.

Threatened flora species with a substantial proportion of known locations outside ACT conservation areas include Black Gum (Eucalyptus aggregata), Button Wrinklewort (Rutidosis leptorrhynchoides), Tarengo Leek Orchid (Prasophyllum petilum), Canberra Spider Orchid (Caladenia actensis), Small Purple Pea (Swainsona recta), and Murrumbidgee Bossiaea (Bossaiea grayi).

Representation of threatened ecological communities in conservation areas
Of the three ecological communities listed as endangered in the ACT, only High Country Bogs and Associated Fens are fully protected in ACT conservation areas.
Natural Temperate Grassland has just over half of its known distribution in ACT conservation areas, and Yellow Box/Red Gum Grassy Woodland has only 30% reserved. However, both Natural Temperate Grasslands and Yellow Box/Red Gum Grassy Woodland have substantial proportions of their extent on national land at nearly 30% and 20% respectively, and are subject to management as required under the EPBC Act.
Despite this, nearly half of the ACT’s Yellow Box/Red Gum Grassy Woodland is not reserved, and some 20% of Natural Temperate Grasslands are also unreserved. The low levels of reservation add to the pressures on these communities and the species they support.
For the 11 vegetation classes assessed, 8 had more than 80% of their extent protected, and another 2 had over 60% of their extent protected. The most under-represented vegetation class was Southern Tableland Grassy Woodlands which only has 30% of its extent in conservation areas.

The least protected vegetation communities in the ACT are woodland, grassland and open forest communities, with under 30% of their extent protected in conservation areas.

Native vegetation: extent
It was not possible to determine changes in the extent of native vegetation over the reporting period (2015–16 to 2018–19).
Native vegetation losses are estimated to be small and mainly due to changes in land use due to urban development.
It is important that there is consideration of the cumulative impacts of small modifications to habitat, because these can lead to thresholds being crossed unknowingly and unintentionally for at least some aspects of vegetation and ecosystem health.
Most of the ACT’s vegetation loss has been from historic clearing on lowlands and modification of ecosystems for agriculture and urban development. It is estimated that there has been little change in the distribution of upland vegetation types.
Prior to European settlement, Natural Temperate Grasslands were thought to cover over 25,000 hectares or 11% of the ACT area, but today they only cover around 1,100 hectares, less than 1% of the ACT.
For Lowland Box Gum Woodlands, the pre-European settlement distribution was thought to be over 47,000 hectares or 20% of the ACT area, but these woodlands now only cover some 11,500 hectares, around 5% of the ACT.

While the loss of native vegetation due to urban development remains of concern, it is unlikely to be the largest source of native vegetation change in the ACT. Chronic degradation of habitat condition, mainly in fragmented landscapes, is a significant problem in the ACT.

There has been substantial revegetation in the Murrumbidgee River Corridor nature reserves, Lower Cotter Catchment and other areas of public lands to restore habitat and connectivity. This has included planting some 100,000 tube stocks and 200 kilograms of native seed.
In addition, there were revegetation activities on some 1,500 hectares of private land between 2015 and 2018, mainly through works undertaken by Greening Australia.
Native vegetation: condition
It was not possible to determine changes in the condition of native vegetation over the reporting period (2015–16 to 2018–19). Nor was it possible to provide an overall assessment of vegetation condition.
Climate change has led to an increased occurrence of dieback in the ACT.

There has been a significant increase in the incidence of dieback in Blakely’s Red Gum (E. blakelyi).

Significant areas of riparian vegetation on the Murrumbidgee and Molonglo Rivers have poor connectivity particularly in areas outside of reserves.
Since 2009, woodlands, Natural Temperate Grasslands and secondary grasslands have shown an increase in native plant species richness suggesting an improvement in condition.
However, woodland native species richness has seen a slight overall decline since 2014, possibly due to drought conditions experienced in 2018.
Native grass cover across all vegetation formations has been declining since 2012. This decline does not appear to be linked to drought. More analysis is required to determine if it is linked to management practices. The decline in this indicator is a concern because it has implications for fauna habitat and for weed invasion.
In 2018, only 34% of the total area of native vegetation assessed was found to be within the optimal tolerable fire interval to maintain vegetation communities, 53% was below minimum TFI (fire interval too short to maintain vegetation in its optimal state), 7% above the maximum TFI (fire interval too long to maintain vegetation in its optimal state), and 6% classed as long unburnt.
Native vegetation growth stages across the ACT reflect a similar pattern to tolerable fire interval status, with extensive areas of the uplands being dominated by early and young growth stages due to the 2003 bushfires. This has significant implications for biodiversity, especially for fauna that require older growth stages.
In the longer term, conservation needs to focus on diversifying growth stages. In the lowlands, this can be achieved through the ecological burning of late
and mature growth stages for vegetation resilient to fire. However, in the uplands achieving growth stage diversity will require time and deliberate protection of the relatively rare older growth stages from prescribed fire and bushfire until more of the landscape reaches post-fire maturity.
Invasive terrestrial plants and animals
Invasive plant and animal species continue to pose a major threat to biodiversity, ecosystem health, primary production, social amenity and human health.
Data on management outcomes clearly demonstrates the value of invasive species management to control established populations and to eradicate new outbreaks where possible.
Management results also show the risk of invasive plant and animal populations re-establishing themselves in the absence of ongoing control.
Invasive terrestrial plants and animals: invasive plants
There have been 592 invasive plant species recorded in the ACT.
Data on management activities clearly demonstrates the value of invasive plant management to control established populations and to eradicate new outbreaks where possible.
Management results also show the risk of invasive plant populations re-establishing themselves in the absence of ongoing control.
Over the reporting period (2015–16 to 2018–19), 54,000 hectares of invasive plant control was undertaken in the ACT for over 100 invasive plant species.
Serrated tussock accounted for the largest area treated at nearly 14,000 hectares, followed by St. John’s wort (over 10,000 hectares), blackberry (7,700 hectares) and African lovegrass (6,900 hectares).
Invasive terrestrial plants and animals: invasive animals
It was not possible to comprehensively determine the distribution and abundance of invasive animals in the ACT for this report.
Records show the presence of 64 introduced animal species in the ACT, including 17 mammals, 33 birds, 2 lizards, 1 frog and 11 fish.
The invasive animal species of most concern in the ACT are feral pigs, deer, foxes, rabbits, horses and wild dogs, with control programs undertaken for all these pests.
Rabbits are the most widespread and damaging invasive animal in the ACT, impacting on natural and rural lands. Rabbit control is the most common invasive animal management undertaken.
Deer and horses have the potential to cause significant environmental damage to sensitive alpine bogs and fens, woodlands and agriculture.
As with invasive plants, to be effective the management of mobile and rapid breeding animals such as rabbits requires ongoing control.
Despite the significant impacts on native wildlife, the ACT has no formal programs to manage stray or feral cats. The exception is cat containment legislation for new suburban developments.
Foxes have been shown to have a devastating impact on native wildlife in the ACT with the potential to cause local extinctions of vulnerable native species. Foxes were responsible for the loss of Bettongs released in the Lower Cotter Catchment between 2015 and 2017.
The restoration of native populations is dependent on the effective control of invasive species.
Annual kangaroo culls are undertaken to protect the ACT’s grassy ecosystems from overgrazing. Between 2009 and 2019, over 22,000 kangaroos were culled. The largest annual cull was 4,035 kangaroos conducted in 2019. The annual cull numbers have increased annually since 2013, mainly due to the increased number of management sites.

Indicators