Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Ann Hamblin, Bureau of Rural Sciences, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06748 5
Many land-related changes that result from human activities take a long time to show themselves. The response time depends on a complex interaction of climate, geology and patterns of land development.
It is now well recognised that the management of Australia's lands has resulted in many land degradation problems. This recognition is not new. Tension between a desire to conserve and sustain Australia's unique flora and fauna and the pressure to develop and exploit have been persistent themes (Bonyhady 2000).
In the past decade there have been serious attempts by governments and primary industries to understand the Australian ecosystems more fully, and work within sustainable limits. Much of this has been driven by a realisation of the need to remedy past degradation. This response is particularly evident in southern Australia, where the extent of past degradation is greatest and most conspicuous. However, the continuation of poor practices and inappropriate land uses and landscape change continues in many instances.
Australia is in the process of transition from a predominantly primary industry-based economy to an advanced post-industrial economy. This change is being accompanied by a change in the value placed on land and has altered the relative revenues obtained from different land uses. In many regions of established agricultural land use strenuous attempts are being made to improve environmental, economic and social sustainability. Despite major adjustments to many agricultural industry sectors in the past decade, serious doubts exist as to whether these industries can finance the adoption of remedial and truly conservatory farming systems (NFF-ACF 2000).
In the light of these serious attempts to rectify the very significant environmental damage already done to the land, and its impacts on biodiversity conservation and water quality, it is worth assessing the extent to which current Australian policies on land are consistent with stated objectives on sustainable development. What is clear is that we are still making mistakes (see Will we ever learn). This report shows that in some parts of the continent the constraints of climate and soil are now appreciated. However, inappropriate land uses continue, driven by individual economic imperatives and, in some cases, an unwillingness to face, or accept, the reality of climate variability and the likelihood of environmental deterioration.
Land use fitted to climate?
In the 1860s the Surveyor-General of South Australia, George Goyder, correctly identified the limits to safe cropping in South Australia from natural vegetation associations. Responding to a question as to whether his famous line (closely following the edge of the 10 inch or 250 mm rainfall region) represented the boundary between cropping and pastoralism he replied:
"It does to a certain extent, but there is some of the country where, although the soil is eminently suited to tillage, and will grow anything, the peculiar position of it and its openness to hot winds render it such as can be only safely continued as pastoral land. That land is both inside the line and outside it, and is only fit for pastoral purposes."
Nevertheless settlers pushed north of 'Goyder's line', only to have disastrous crop failures 10 years later; and some are still cropping north of the line in some areas. Today the successful farmers now have a suite of risk management practices that provide operational and financial buffers, using conservation tillage, growing high value grade wheats, and forward selling.
In 1917 Professor J.W. Patterson of the University of Western Australia presented soil samples and a report to the Royal Commission on the Mallee and Esperance Lands, claiming a third of the area was too saline for profitable farming. The Commission's response (quoted in JAWA 1997) was:
"The Commission having given the question close condideration strongly urges that scientific prejudice against our mallee lands be not permitted to stand in the way of their being opened up for agricultural purposes."
Advice from other scientists, such as the pedologists Burvill and Teakle in the 1920s and 1940s, similarly went unheeded. It was not until 1981 that the first clearing restrictions were imposed in south-western catchments of WA, and this state now takes the challenge of secondary salinity very seriously. In sectors of the farming community in Queensland secondary salinity is still not appreciated as a consequence of clearing (NLWRA 2001a).
Desertification and risk management
In the 1890s and 1900s, the 1920s and 1930s, and again in the 1980s and 1990s, there were a number of government inquiries into the financial distress and desertification of the pastoral regions. Concern over the effects of herbivore grazing in semi-arid and arid rangelands has been expressed repeatedly in Australia, (e.g. Royal Commission 1901), particularly during the devastating effects of rabbit plagues in the pre-myxomatosis drought era of the 1940s as the following passage illustrates:
"The plain truth is that the pastoralists' existence will always be a gamble in the Australian inland, where the profits of the good seasons must be balanced against the losses of the droughts. The only sound and sarisfactory pattern of settlement in this region...must be built up of units each capable of meeting the recurrent droughts on its own resources. If the nation prefers to enforce a different system, based on the assumption that the occurrence of droughts can be ignored, it should be understood that it will be called on to pay for tis preference in good hard cash. Settlement on such a basis must in the end be subsidized, and subsudized more and more heavily as time goes on." (Ratcliffe 1938).
One of the most recent of such reports (Kerin and Hyder Consulting 2000) proposes a radical change to the tenure act that governs the use of the Western Division. However, we seem no nearer to achieving to this type of change than we were sixty years ago.
The following is a short summary of the issues that this report concludes are significant to Australia.
- Accelerated erosion and loss of surface soil
- Physical changes to natural habitats
- Introduction of novel biota into native habitats and communities
- Secondary salinity and acidity
- Nutrient and carbon cycling
- Soil and land pollution
- Soil erosion remains a perennial, but unglamorous problem, given the slow rates of soil formation.
- Measuring and managing grazing pressure, particularly in pastoral country-a critical area is the impact upon estuaries, reefs and river systems where pollutants within sediments (e.g. DOM, pesticides, nitrates, phosphates) lead to pollution of another system.
- Lack of ways of documenting and differentiating what has happened in the past from current areas and extents of accelerated erosion, especially the loss of topsoil impairs our ability to assess how well management practices are performing.
- Land clearing is a serious issue, in particular the problem of actually getting a definitive measure of the extent of clearing-with implications for greenhouse, potential salinity impacts and potential erosion impacts.
- Increasing pressure on AQIS and NRM incursion threats with a constantly increasing number of travel movements both international and internal.
- Actually getting on top of some of the weeds of national significance; herbicide resistance is a significant agricultural problem (but not so much an environmental one).
- Community perceived risk of GMO escapes is much greater than the best scientific assessment, which new legislation (December 2000) is designed to manage.
- Problem of getting adequate resources to tackle non-agricultural pests and diseases because little infrastructure or resources are devoted to this issue.
- The big issue is insufficient resources available to tackle even those species of identified national significance, let alone the threat from new incursions, and spreads of 'sleepers' or existing known problems (e.g. diamondback moth, phytophthera spp, western flower thrips-which all attack hundreds of endemic species). Risk assessment protocols, strategies for containment etc. are all very weak for exotic threats of non-agricultural species.
- The extent and likely spread of dryland salinity is now better understood, but can we develop agricultural systems that prevent recharge?
- The problem of massive increase in demand for water coming from an increasing number of users.
- Irrigated agriculture is rapidly expanding, especially outside traditional areas of reticulated systems, because of greater returns, reducing climate variability risk, etc.
- Some catchments and systems are now over-allocated (e.g. Namoi, five times over-allocated; Snowy, demands from traditional users versus urban populations and environmental flows etc.).
- Acid soils and acidification goes unrecognised as a contributory factor to low water use efficiency, yet the technology to improve plant water use is well developed.
- Carbon cycling in relation to land management issues:
- e.g. carbon credits-no well developed systems of commercial operation or accounting are yet established,
- incorporation of perennial vegetation into farming systems. The theory is well understood, but economic incentives and technical constraints under present land uses are still to be tackled.
- Nutrient balances of farming systems- an environmental issue-especially for intensive industries such as feedlots, in regard to off-site losses and eutrophication. It brings into question the level of industry self-regulation versus systems of government regulation and compliance. This is a critical issue. It is too costly for governments to police all types of effluent outputs, especially from diffuse sources, but is a difficult area for which to devise appropriate minimisation strategies.
- Lack of data on pesticide use and consequent inability to accurately measure potential risk or environmental impacts restricts sensible policy development and comprehensive use of 'clean green' labels. Also there is difficulty getting all stakeholders to a common view. There is no appropriate lead agency that is able (or willing) to take the role of monitoring, data acquisition and management of feedback.
- Lack of data on contaminated sites (industrial, urban, rural processing, orphan sites, rather than mining).
- Locations of past contaminated sites and their management is a 'grey' area: the regulation of small and medium enterprises that fall outside NPI are not well documented.
- Lack of scientific knowledge of impacts on biota and pathways to groundwater and other water bodies still hampers monitoring and regulation.
- The probable cost of clean-ups is often prohibitory except where high visibility or political pressure exists.
In comparison with the situation reported in the 1996 State of the Environment Report, the past five years have seen an increase in institutions and laws to protect the environment. However, Australian society is still struggling to come to terms with the scale of change that is required to halt or restore past and current land degradation.
- The dynamic nature of land use and land tenure. Big changes in tenure in inland Australia have occurred in the past 15 years particularly in relation to Aboriginal lands (see Human Settlements Theme Report for more detail). In addition substantial changes in land use have occurred, mainly on freehold land, throughout the eastern coast of Australia where lower value agricultural lands have been purchased for more profitable sub-division for residential housing, shops, tourist and service centres. This is leading to changes in the 'value prism' (how we see and value land for different purposes).
- Many current government programs on natural resource management are targeted at a stewardship ethic for existing land use, taking the view that the land will continue to be in the current land use, rather than changing use (such as farm forestry, recreation on former farms, marinas, hobby farms).
- The lack of sufficient finance to rehabilitate and restore vast areas of degraded rural land has been heavily emphasised in recent policy documents from non-government sources. Government response is to consider further ways of cost sharing through partnerships, but these have not proved successful in adequately addressing the overall financial demands so far.
- Laws and tenure conditions have traditionally enshrined rights to primary industries over rights of community, (water and health, biodiversity etc.) and these are now being increasingly challenged. There has been a rapid development of new property rights, with water being uncoupled from land, and new markets for salt and carbon trading developing.
- The value of ecosystem services is being seriously investigated, and environmental benefits of such functions as waste recycling by micro-organisms and fertilisation of food crops by insects is being estimated. Private sector investment is occurring as well as public research (e.g. the Myer Foundation project).
At present there is a strong focus on salinity and greenhouse as the two major land issues, but several others may be more important. These could include:
- Inadvertent introduction of a devastating pest or disease. This is always a potential risk, and the threat from the myrtaceous rust that is now devastating eucalypts in South America, for example, would be a case in point.
- Acidification. Acidification has been largely overlooked, as has the problem of managing dispersive sodic soils, both of which cover vast areas of Australia and contribute as much or more to poor water quality, secondary salinity and loss of ecosystem function than does clearing. These problems are 'sleepers' because they have not been able to be elevated to the position of political concern enjoyed a decade ago by algal blooms, or currently by salinity.
- Pesticide residue levels and pesticide resistance. At present these are considered of local and topical concern only, but the lack of knowledge about usage, extent and level of residues and resistance are very worrying, both in terms of managing pests, weeds and diseases, and in validating claims for 'clean and green', which is a strong trade imperative for primary produce in Australia.
The scale of community and government response and action on the ground is still inadequate relative to the scale of the problem in the case of salinity and erosion. Evidence for this includes the following:
- Estimates for land clearing (and tree loss) vary from 424 444 ha in 1999 (AGO 2001) and 564 800 for 2000 (ACF 2001) and an annual loss of 428 280 ha in the period 1990-95.
- Net loss (all gains versus all losses) was about 232 210 ha in the 1990-95 period, and AGO estimates for net losses from clearing in agriculture are twice the sinks occurring through forestry plantations, tree planting and other sequestration.
- Net loss is occurring despite the very substantial efforts of the NHT in revegetation and remnant vegetation preservation. The Bushcare program aims to protect and revegetate a total 300 000 hectares in 5 years, and while Landcare projects have added several million trees to the environment in the past decade, this is probably less than has been lost through natural decline and clearing native vegetation.
- Recent estimates from the ACF and NFF (NFF-ACF 2000) indicated that the current level of capitalisation for natural resource restoration, of $640 million per year, is only 10% of the $6.4 billion that their paper suggests is needed.
- Recent climate change studies show that there is annual to biennial fluctuations in the amount of carbon dioxide entering the atmosphere; globally, twofold variations are not uncommon.
- Variation in rainfall on the Australian continent likewise has a 20-50% variability between wet and dry years (ENSO variation), translating into differences in net biomass of 20-50%.
- These oscillations are so large that only the very largest anthropogenic changes are likely to have any measurable impact.
- Modelled estimates of the revegetation needed in those river basins that have less that 25% perennial vegetation is for 30-50% of cleared land to be restored to full perennial cover. Only a handful of subcatchments (principally in south-western Western Australia) are achieving this.
- The chronic problems of under-performance in grazing industries are not being solved by current levels of industry restructuring.
- Most meat and wool production is not sufficiently profitable, except on large corporate farms, or where the livestock are part of mixed farming enterprises, for the industries to have sufficient resources to invest in natural resource management, let alone restoration. Alternatives could include:
- destocking in most financially and environmentally stressed areas with farmers paid as land stewards,
- deliberate rescheduling of those areas that are valuable for other purposes, such as water catchments, biodiversity value and tourism potential, for alternative land uses, rather than waiting for market forces to achieve this (which may not occur if land becomes too degraded).
- Changes in society's attitudes to land and what it is used for is increasing in southern and coastal Australia. These include:
- recent natural resource management policies of the Commonwealth government emphasise greater collaboration and partnerships among stakeholders, a range of economic and regulatory interventions, alternative wealth generation, education and research to improve environmental condition,
- competition for land in high value zones (peri-urban, coastal, along transport routes), is shifting land use from predominantly agricultural to multiple use, or intensive high value products.