SoE 2003 > Biodiversity > 6.3 Terrestrial species diversity

6.3 Terrestrial species diversity

Two more species have been declared extinct in NSW and, while the number of recovery plans for threatened species has increased, many more species are now listed as threatened

The diversity of terrestrial species in NSW remains under threat. The scale of the problem is becoming clearer as the processes for recognising terrestrial species and ecological communities at risk improve. Two additional species have been listed as extinct since State of the Environment 2000 and there has been an increase of 18% in the number of species and communities listed as endangered or vulnerable in NSW.

Recovery planning for threatened species has improved recently but is not keeping up with the increase in newly threatened species and communities: finalised recovery plans are up by 44, but new listings increased by 137.

NSW Indicators

Importance of the issue

It is clear that human activities have a major impact on terrestrial species and ecosystems. Biodiversity is the basis for maintaining sustainable human societies and a healthy environment. An environment rich in genetic diversity, species and ecosystems is a powerful defence against changing conditions. Loss of diversity weakens essential natural ecosystems and ecosystem services. It can have impacts on a range of industries, including farming, forestry, fisheries and tourism, and reduce opportunities for new technologies in the pharmaceutical and agricultural industries. Declining biodiversity also degrades aesthetic, recreational and cultural aspects of life.

The loss of biodiversity in NSW is ongoing. It is not possible to be certain of its true level as the number of species is much greater than the state of knowledge about them (Possingham et al. 2002). In addition, biodiversity loss occurs naturally, such as through climate change and natural catastrophes, as well as through human activities. However, natural species loss is generally much slower than human-induced loss.

A common criterion for extinction is no sightings of a species for 50 years. This is the measure used by the Threatened Species Conservation Act 1995 (TSC Act) to define 'extinct'. A number of NSW species have not been seen for over four decades and, since State of the Environment 2000 (EPA 2000b), two species passed the 50-year horizon. These are the Lord Howe Island ground weevil (Hybomorphus melanosomus) and an orchid (Caladenia rosella).

One-third of the terrestrial vertebrate animals in NSW are considered to be under threat (NPWS 1999a). The proportion of terrestrial plants under threat is much lower at about 3%, but with a total of over 15,000 species, the number is significant. Over the past three years, the number of endangered and vulnerable species, and endangered ecological communities and populations has grown considerably. By December 2002, a total of 75 species had been added to the endangered list and 19 to the vulnerable list since the last State of the Environment report (see Table 6.3).

Table 6.3: Terrestrial NSW species, populations and ecological communities extinct or under threat

Source: TSC Act, as at December 2002

Note: ^(a) These are estimates from NSW National Parks and Wildlife Service.

The number of endangered ecological communities has doubled. However, this partly reflects improved processes for recognising and assessing communities nominated as potentially at risk, as well as the rate at which they are becoming endangered. This trend is expected to worsen because better research methods will identify some species and communities which are already past their limit of survivability.

Many species are not listed as 'vulnerable' or 'endangered' by the TSC Act even though their abundance and range may be declining. This is because their overall chance of survival in NSW is considered good. As a result, the listings do not give a complete picture of the broader decline that is occurring across the State as habitats shrink and become isolated. Changes to the size and range of individual populations can therefore be a useful supplementary measure of biodiversity decline.

The diversity of bird populations is a useful indicator of biodiversity because of their sensitivity to environmental changes. Surveys for the preparation of two bird atlases (Birds Australia 2002; Reid 2000) found that the direct loss of bird habitat has been significant and fragmentation of terrestrial ecosystems was placing pressure on their populations. Higher than expected numbers of threatened species have been found among ground-nesting and ground-feeding birds, with significant falls in population reported in up to half of the State's bioregions. Decreases in woodland species were also found. The surveys suggest that clearing of land for agricultural use is having the greatest non-climatic impact on bird populations. Other significant pressures include intensified land use and urbanisation, introduced predators and changed fire regimes. Climate change is also putting pressure on bird species, with alpine species in NSW and Victoria declining, possibly due to warming in upland areas (NLWRA 2002).

Response to the issue

Broad responses to terrestrial ecosystem decline were discussed in Biodiversity 6.1. Additional responses have been developed to deal specifically with difficulties faced by individual terrestrial species and communities as discussed below. The Australian National Strategy for the Conservation of Australian Species and Communities Threatened with Extinction (ESAC 1992) provides a national framework for managing threatened species. In NSW, the TSC Act is the main legislative tool for the protection of all threatened terrestrial plant and animal species.

Recovery and threat abatement plans

Recovery plans for threatened species, populations and communities are a major component of the NSW Government's response to declining species diversity. The aim of a recovery plan is to evaluate the key threats to the species concerned and recommend measures to counteract them.

The NSW National Parks and Wildlife Service (NPWS) is responsible for preparing recovery plans for species, populations and ecological communities listed as threatened in the TSC Act. Table 6.4 shows the number of recovery plans required and approved since State of the Environment 2000 (EPA 2000b). Of the 47 recovery plans approved, five are multi-species plans covering a total of 60 threatened species. Another 206 plans are in various stages of preparation, including 20 multi-species plans covering a total of 284 threatened species, populations and ecological communities.

Table 6.4: NSW terrestrial recovery plans

Source: NPWS data, as at December 2002

Note: ^(a) Excludes species presumed extinct

Recovery plans are implemented through a wide range of measures including surveys to locate threatened populations and ongoing monitoring; management of habitat, such as weeding and fencing to contain threats; baiting of predators; reducing competition from introduced species; and education and awareness programs to get the assistance and support of the community.

The NPWS is required to prepare a threat abatement plan for each key threatening process listed under the TSC Act. These plans outline methods to abate, ameliorate or eliminate the threat. By December 2002, a total of 16 threat abatement plans were required and one had been approved for the red fox (Vulpes vulpes). A threat abatement plan for the mosquito fish (Gambusia holbrooki) has been submitted for approval and a draft plan for bitou bush has also been completed.

Planning/regulatory tools and community activities

There are a number of specific planning and regulatory requirements relating to threatened species. Proponents of certain developments that are likely to significantly affect a threatened species or critical habitat are required to prepare a species impact statement under the Environmental Planning and Assessment Act 1979. Threatened species must also be considered when a State environmental planning policy, regional environmental plan or a local environmental plan is being prepared.

Any activity likely to harm a threatened species, population or ecological community or damage its habitat requires a licence under the TSC Act, except for specified exemptions such as routine agricultural activities.

The involvement of the community in conservation activities is of enormous benefit to biodiversity. There has been a growing level of community participation in volunteer initiatives to conserve biodiversity and protect native vegetation across NSW. A wide range of activities is supported by government through funding mechanisms such as the Natural Heritage Trust. Many of these actions to conserve, protect and restore native vegetation, habitats and ecosystems have significant benefits for threatened species, populations and communities.

Numerous community programs are continuing with the efforts of volunteers across the State (see EPA 2000b). The Threatened Species Network, for example, is community-based and jointly administered by the World Wide Fund for Nature Australia and the Natural Heritage Trust's Endangered Species Program. The network aims to increase public awareness and involvement in the protection and recovery of Australia's threatened species and habitats. It facilitates the involvement of individuals and community groups in on-ground conservation projects to secure threatened species and their habitats. The network also provides financial assistance to community groups for research, monitoring, habitat management and education projects.

Effectiveness of responses

Recovery plans have been effective in assisting the long-term survival of many priority species. For example, recovery actions for the little tern (Sterna albifrons) have successfully increased their numbers in NSW (NPWS 2000).

The pace of completion of recovery plans has increased recently. However, it is uncertain whether the long preparation process for recovery and threat abatement plans will keep up with increases in threatened species and communities.

Some existing populations in the wild may have already been pushed past the point of no return because of declining numbers or loss of habitat. Deciding between 'worthwhile' and 'non-worthwhile' species for recovery is both difficult and extremely contentious, but may have to be considered in the future (Possingham et al. 2002).

Future directions

Government needs to continue its efforts to increase the rate of preparation of recovery and threat abatement plans.

Government should also continue to control developments likely to cause the loss, depletion or degradation of habitat, species or communities. It should also promote practices that protect or restore native habitats and minimise or reverse the fragmentation of habitat, such as creating wildlife corridors.

Government and landholders can work to extend protected areas across the ecosystems, habitats and populations most at risk in NSW. They should also work in partnership to develop better models for conservation on private land.

Government and industry should support community and non-government conservation activities in recognition of the benefits of this work for preserving biodiversity.

Linked issues

2.1 Population and settlement patterns

3.2 Climate change

4.1 Land-use changes

4.3 Induced soil salinity

6.1 Terrestrial ecosystems

6.2 Native vegetation clearing

6.4 Introduced terrestrial species

6.5 Fire