Biodiversity
Theme commentary
Steven Cork, Land & Water Australia and CSIRO
Paul Sattler, Paul Sattler Eco-consulting Pty Ltd
Jason Alexandra, Alexandra and Associates Pty Ltd
prepared for the 2006 Australian State of the Environment Committee, 2006
Executive summary
Despite large investments and some promising responses, biodiversity in Australia continues to decline. Because of ongoing pressures and the legacy of past pressures, we cannot expect to see major reversals in this decline in the near future.
This is the third national state of the environment report that raises concerns about the lack of long-term, systematic biodiversity information that would allow firm conclusions to be drawn about the details and mechanisms of this decline and, especially, whether responses are being effective or are likely to be effective.
Australia’s biodiversity is of incalculable value to this and future generations. As well as underpinning the culture of Australian society, it provides raw materials (for example, water, fibre, food products, chemicals) and services (for example, water filtration, pest control, waste disposal, stabilisation of waterways and coasts, regulation of air quality) that support industries as diverse as tourism, forestry, agriculture, fishing, boat building, manufacturing, human life and wellbeing in general.
Data on the relative strength of pressures on biodiversity, changes in the number and status of species, and the effectiveness of responses are too patchy in geographic spread and too narrowly focused on a few pressures, species or responses. Data are also not systematic enough to allow firm conclusions to be drawn about changes from one state of the environment reporting period (1997, 2001, 2006) to the next at a national scale. A greater commitment to long-term ecological research and strategic monitoring of key biodiversity indicators is required to allow assessments of change over these time scales.
Some broad conclusions can, however, be made about trends operating over a longer time frame. It is clear that the major pressures on biodiversity that have been operating for decades are still strong and will continue to drive decline in biodiversity across large areas of the continent, together with new and emerging pressures. Some responses to biodiversity decline are beginning to have effect and promise to provide substantial future benefits. Involvement of people from across Australian society in actions to conserve biodiversity is providing important human and financial resources.
A wide range of experts across Australia identify some of the major pressures that threaten biodiversity on a national scale (not in order of significance) to be: total grazing pressure, weeds, invasive organisms, changed fire regimes, and habitat fragmentation. For example, grazing and the conversion of pastures to support it have reduced the extent of native grasslands in a range of temperate Australian ecosystems to less than two per cent of that present in 1750 and have simplified the structure and quality of habitat for animals in these systems. As of 2004, a total of 95 species of animals and 68 plants were listed under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act) as threatened by at least one invasive organism and it is estimated that Australia gains around 20 new pests or diseases each year; and major habitat changes have occurred in both northern and southern Australia due to changed fire regimes, especially with widespread drought conditions in recent years.
Other pressures are of particular significance in some regions. These include vegetation clearing, pollution of waterways by nutrient enrichment, changed hydrology, and salinity, which are of concern both because of their direct effects and their interaction with other pressures.
These major pressures are interrelated and operate over a range of scales, from local to regional to national. They have been operating over long periods of time, resulting from patterns of economic development, population growth in Australia, and global processes like increased movement of species within and between countries. The pressures have a legacy (often called an ‘extinction debt’) that will continue for decades to come, even as Australia takes remedial action. Notably, vegetation clearing may become a less significant direct threat in the future. Most states and territories have now introduced legislation aimed at regulating broadacre vegetation clearing, but the legacies of past vegetation clearing—including changed hydrology, habitat loss and fragmentation, and impacts on seed supplies and regeneration of native vegetation—remain strong drivers of biodiversity decline.
Climate change will further compound and intensify pressures on biodiversity, especially by affecting rainfall patterns, and hence fire frequency, affecting regeneration of vegetation, and changing where plants and animals can live. Different pressures are more or less important in different parts of Australia. Minimising their impacts will require improved knowledge and strategic action tailored to each part of the continent.
Notable recent responses to pressures on biodiversity include: major policy reforms intended to phase out broadscale vegetation clearing, and commitments to providing environmental flows for some rivers and wetlands. These reforms should make significant contributions to protecting Australia’s biodiversity in the future.
Significant investment has been made through the Natural Heritage Trust (NHT) and the National Action Plan for Salinity and Water Quality (NAP). Funding of regional projects through these programmes resulted in increased awareness, interest, and community involvement in biodiversity conservation. Detailed evaluations of the effectiveness of these ambitious programmes are not yet available. Because responses are dispersed between all tiers of government, regional organisations, communities and industries, coordination, measuring of biodiversity outcomes, and identifying which actions were or were not successful remain major challenges.
National objectives and targets for biodiversity conservation have been agreed by all states and territories other than Queensland, Tasmania and the Northern Territory. The only major review available on progress towards these targets (Griffin NRM Pty 2004) concluded that progress was encouraging on only 38 per cent of the 29 targets which were mostly policy, regulatory or planning process targets rather than biodiversity outcome targets.
Effective management of biodiversity in Australia requires an improved capacity to collect, synthesise and interpret key information and to consider biodiversity in the context of broader environmental change. Planning effective management responses requires a commitment to significant increases in research on understanding and measuring biodiversity and its roles in ecosystem function, mapping of vegetation and ecosystems at appropriate scales, and development and implementation of monitoring frameworks at a range of scales (regional, state and national). Monitoring should directly lead to adaptive management and be incorporated into an experimental learning framework that tells us how different strategies perform.
The National Land and Water Resources Audit’s Australian Terrestrial Biodiversity Assessment (NLWRA 2002) provided an important review of information and trends related to various elements of biodiversity at a bioregional scale across the continent. There is a need for ongoing collection and dissemination of this type of information to allow assessment of progress in biodiversity conservation and to support strategic interventions to protect biodiversity.
Many responses to biodiversity decline have been reactive. In some bioregions—particularly those subjected to intense development for urbanisation or agriculture—major programmes of ecosystem restoration are required. Restoration programmes need to be planned carefully and based on best available science, to deliver multiple biodiversity and other natural resource benefits. Prevention is more cost effective than restoration, and proactive and anticipatory policies are required that focus on preventing ecosystem and species decline.
Australia’s terrestrial protected area system is a central strategy in protecting biodiversity and, while it has increased to cover about 10.5 per cent of the continent, it is not representative across bioregions. Specific effort is needed to meet commitments to develop a fully representative system across all bioregions where the opportunity remains.
As knowledge of Australia’s ecosystems improves so does the understanding of the scale of the pressures and the challenges for responding to those challenges. The authors believe that implementation of programmes across the broader landscape has not been sufficiently proactive, strategic or adequately resourced to address the accumulating impacts that are driving biodiversity decline.
Stemming biodiversity decline will require biodiversity initiatives in which detailed responses are tailored to each bioregion of Australia and are sufficiently understood to focus the current investment in regional delivery processes. A basic platform of knowledge and community commitment now exists to develop such initiatives.