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
The term 'world's best practice' is often used to describe an agreed standard in management, and has sometimes been applied to natural resource management. It is not a term that sits very comfortably with many advisers or landholders, because of differences in society's value systems (see Are net primary productivity and total grazing pressure in balance? earlier in this section). Local conditions, and production objectives may be so diverse that there is seldom one 'best practice' that provides a fixed and static checklist, in the same way that the International Organisation for Standardisation (ISO) series of standards can. What should be widely achievable is the adoption of sensible, precautionary practices that seek to minimise ecosystem disruption, and are accepted as the best that any particular level of understanding and technology can achieve within the constraints of commercial operation.
'Best management practice' may therefore be more realistically called 'current recommended practice' (Murray-Darling Basin Commission 2000). Such recommendations are the combined synthesis of government resource management agencies, independent scientists and leading farmers who have tested the recommended practices within the context of the financial, technological and social constraints of the land users. It is often complemented by current action-learning iterations of producers and scientists working together. In the case of erosion control, many of the recommended practices were universally understood and well established, with the essential aspects of the physics of water and wind erosion having been worked out in the 1930s to 1950s (see for example Bagnold 1941; Weaver 1937; Wischmeier 1959). Their adoption, however, has only become widespread as a greater understanding of the social aspects of adoption has led to greater emphasis on Landcare and related human systems.
The Kimberleys cover twice the size of Victoria. Half the land is in pastoral leases and the rest is in national parks, Aboriginal and defence lands. There are approximately 25 000 people in the Kimberleys, with a growth rate of 2% per annum.
Today's big income earners are tourism, bringing in $140 million (1997 figures), and growing at 20% per annum in the past five years, and mining (primarily from the Argyle diamond mines) earning a massive $551 million per year. Pearl and fishing earn a further $150 million. Spectacular areas of natural beauty and dramatic geological formations exist in the Mitchell Plateau and the Bungle Bungle National Parks, which were too difficult to access until recently. Improvement in the region's accessibility, the rising interest in 'unspoilt nature' and the investment in good transport and communications for mining has stimulated the rapid expansion of eco-tourism.
For 140 years European development focused heavily on pastoralism, yet only 8% of the pastoral leases are rated as being of high quality (Wilcox and Cunningham 1994). Ninety-eight pastoral leases run as 60 businesses across 22 million hectares, supporting 450 000 cattle. In 1997 they had a gross value of only $29 million per year (1997 figures), compared with the Ord Irrigation Area (OIA) which produced a gross value of about $42 million from just 13 000 irrigated hectares of melons, vegetables, bananas, sugar cane and other crops.
Many of the poorer pastoral areas were so badly degraded in the past that some leases were reclaimed by the government and restoration work was carried out. However, since 1985 there has been a concerted effort to shift from open-range systems to managed paddocks, improved herd types, and eradication of feral cattle. Stock numbers have been halved over the period, many watering points have been fenced to prevent river bank degradation, and restrict access by native and feral herbivores. Successful eradication of wild donkey populations has been undertaken through the use of the 'Judas' technique, in which animals fitted with transmitting collars are tracked to find herds.
In the Pilbara, even more extreme has been the shift in importance from pastoralism to high-tech mining in the region to the south of the Great Sandy Desert and Kimberleys. Pastoralism in the Pilbara was never very productive; much of the grazing was on spinifex and hummock grassland. As many of the properties are sheep rather than cattle stations, viability has become increasingly tenuous over a long period. Since the 1960s, the effect of mineral and later gas-oil exploitation has been enormous and spectacular. In 1961 the population was estimated at 3240; in 1997 it was 41 225. Iron ore is extracted from the literal mountains of iron, Mount Tom Price and Mount Newman, and rail freighted to the coast for export, providing $3.6 billion per year in export earnings. In the 1980s the North West Shelf gas and oil deposits started to be exploited, using off-shore platforms and drill rigs. The cryoturbation plant at Karratha liquefies gas for pumping into vessels bound for Asia, earning a further $5 billion a year. Tourism has also expanded, with significant biological and geological rarities such as Ningaloo Marine Park and Millstream National Park, both renowned for the survival of ancient life- forms. Today there is an active program to purchase pastoral lands for both the conservation estate and Aboriginal land.
Feral goats are well adapted to the rugged terrain in the Kimberleys and Pilbara regions.
Mining for iron ore, gold and off-shore gas has transformed the Pilbara.
The National Collaborative Project on Indicators of Sustainable Agriculture (NCPISA) provided some useful baseline information on how Australian farmers are changing their management practices to improve erosion control and the sustainability of their resource base (SCARM 1998). This study considered both the awareness of land managers (defined by their participation in training, information gathering and group activities) and their actual practices on the ground. The data used were drawn from a variety of surveys carried out by the ABS and ABARE, and statistics provided from the National Landcare Program.
The Landcare program has been the major government initiative responsible for developing the ethic of sustainable development among landholders during the 1990s. Since 1997 the Natural Heritage Trust (NHT) has drawn together a number of earlier government programs, together with additional investments contributed by the Federal Government, in partnership with state and territory governments, to address a suite of natural resource management issues (see the section Introduction of novel biota into natural habitats and communities for more detail). The largest initiative has been the Bushcare program, which, while focused on preservation and regeneration of native, perennial vegetation, is also intended to address erosion control. Other programs that are designed to control land degradation include the Murray-Darling Basin 2001 Initiative, the Farm Forestry program, Rivercare and Waterwatch.
A mid-term review of the NHT demonstrated that attitudinal changes initiated with the Landcare movement have expanded to include a wider cross-section of the community, with more training in natural resource management, and behavioural changes across many public and private groups. However the degree of change on the ground that may have physical effect on land degradation has been small (Dames and Moore-NRM 1999). The 10-year-old Landcare program has made a significant contribution to the adoption of sustainable production practices, but the review concluded that economic drivers have been at the base of most changes that have taken place, and could be more deliberately utilised in providing incentive to change. This concurs with findings of surveys assessing the factors affecting farmers' decision to adopt new practices: the most commonly cited factor is the effect it will have on farm profitability (Quiggin and Fisher 1989).
During the 1990s the Landcare movement has provided the main influence in changing land holder attitudes and behaviour to sustainable resource practices. In 1989 the program was launched as a non-partisan, inclusive movement by the combined forces of the National Farmers' Federation and the Australian Conservation Foundation, supported by both sides of Federal Parliament. The Federal Government endorsed the NFF-ACF initiative with The Decade of Landcare and the National Landcare Program. This has seen a steady increase of groups nationally (Figure 24), although the proportion of farmers involved in Landcare has tended to remain around 30-35% over the second half of the decade, with some members and groups declining and others being recruited and increasing.
Figure 24: Number of Landcare groups operating in farming regions nationally during the decade 1990-2000.
Source: ABARE National Landcare Program (unpublished)
The SCARM (1998) report showed a general relationship between group membership and interest in adult learning and training schemes. The majority of land managers first participate in informal or formal courses as members of a Landcare group, then move on to other types of activity (production of farm plans, membership of a catchment management group, implementation of changes on farm). ABARE surveys of Landcare groups have shown that members tend to be drawn from subsets of the whole farming population, where education levels, planning activities and sustainable practices are already rather higher than the average for the sector (Mues et al. 1998; Martin et al. 2000).
In 1998 a random survey of 2% of primary producers indicated that 80% of those surveyed had been or were active in some form of land management group activity (Solutions Marketing and Research Group 1999). Yet, as we have seen elsewhere, this apparently high degree of interaction does not necessarily translate into changes on the ground. The same survey found that only 58% of these landholders had a yearly farm plan, and only 43% of these plans included land and water management, whereas 92% of them had a fire insurance policy, and 82% of them monitored their production costs. Rather, as demonstrated by the mid-term review of the Natural Heritage Trust, the Landcare movement and program have been responsible for substantial attitudinal change among the farming population.
Other government initiatives strongly supported by industry peak bodies have focused on whole-farm planning and financial management, such as the Property Management Planning program run by individual state and territory agencies. This aims to provide integrated physical, financial and succession planning for farmers. Such programs have focused on the urgent need to restructure farm businesses in Australia, given the large proportion of unprofitable farms existing in Australia-at least a quarter of all farms are not making an adequate income to run a business (Tables 8 and 9).
|Net farm income||1988-89||1989-90||1990-91||1991-92||1992-93||1993-94||1994-95|
|Average||54 890||51 944||33 863||29 932||39 632||41 745||45 075|
|Base 25%||14 935||9 831||-1 121||922||4 402||7 381||4 630|
Source: SCARM (1998).
|All broadacre||-3 500||-9 600||-6 400|
|Grains||39 770||18 700||15 700|
|Sheep||-18 030||-29 800||-30 500|
|Dairy||-4 270||5 000||-8 300|
Source: ABARE (2000).
These planning activities are vital to adoption of more sustainable practices where change requires new equipment (such as direct-seeding machines, tree-planters or reticulated irrigation), or increased capital expenditure (such as re-fencing and feral-proof watering points). The NCPISA report reviewed progress in adoption of 21 farming practices monitored by ABS and ABARE, of which 6 are directly relevant to erosion control. Table 10 summarises statistics from various surveys undertaken in the past decade on farmer practices in both the ELZ and ILZ.
|Agricultural practice by census/survey||ELZ
|ILZ (wheat and sheep plus high rainfall zone)||Total
ABS 1993-94 Census
Number of trees/ha planted
ABS 1995-96 Census
% land protected from stock
% cropland with stubbles retained
ABARE 1995-96 Landcare Survey
% landholders protecting drainage lines
% landholders using pitting to check scalds
% landholders establishing trees/shrubs
ABARE 1998-2000 Landcare Survey
% of farms planting trees to stop degradation (3 or more problems)
% farms engaged in farm forestry
ABARE 1998-1999 Cropping Survey
% crop area sown by conservation tillage
% grain farmers in Landcare membership
33 (1996, 1997)
na = not applicable
Sources: ABS (1994); ABS (1996); Mues et al. (1998); Connell and Cooper (2000); ABARE (2000).
These figures are probably more instructive about what they do not tell us, than what they do, since nearly all are expressed as number or percentage of farmers, not of area managed. Only the 1993-94 ABS figures and ABARE grains survey provide information on area cropped or numbers of trees and shrubs planted per area. In the case of conservation tillage the area is now impressive, but in the case of trees the numbers are very small, although the proportion of farmers engaged in better practices is encouraging. ABARE's 1998-99 survey on trees on farms shows that there is a much increased interest in tree planting now compared with the early 1990s, particularly in the higher rainfall regions, where farmers are members of Landcare groups, and where land degradation problems are identified by farmers as severe.
A similar difference between numbers of landholders and area affected was recently reported in South Australia (DEHAA 1998). There, an estimated 91% of cropping farmers in hilly areas and 71% in low-rainfall areas had adopted stubble retention and mulching by 1997. This sounds a spectacular change from the early part of the decade, but the area of stubbled crops increased only by 102 200 ha between years. As South Australia cropped between 2.9 and 3 million hectares during the decade, the area of cropped land that is being protected from wind and water erosion by stubble retention may only have been 12-16% of the land area cropped each year. We know that there is a substantial amount of stubble burning from other evidence too, including direct satellite monitoring.
|Percent of farmers using stubble retention||52% farmers on Eyre Peninsula not burning at all and 60% farmers handling sandhill country differently from rest||71% in low rainfall regions, 56% in high rainfall regions, 91% in hilly, highest rainfall areas|
|Area and % of cropland with stubble mulching||355 248 ha (12%)||457 428 ha (16%)|
|Total area of crop land||3 070 000 ha||2 912 000 ha|
Sources: DEHAA (1998).
These figures are confirmed by ABARE's grains special survey in 1998-99 which showed that while all districts are retaining 40-70% stubble, burning is still occurring on 12-30% of cropland. Between 18 and 31% of farmers who used both stubble retention and burning on the same property, for different reasons (ABARE 2000). While stubble retention appears to be particularly widely practised in the northern region, there was a high statistical variation in this figure (standard error three times the mean), because practices varied greatly from year to year depending on the season.
The reality is that farmers are trying to manage a suite of production constraints and environmental pressures, in which there is no 'best practice' or 'right answer'. In southern Australia, farmers who do not burn the stubble may have to use more herbicides and fungicides. If they risk erosion for the sake of getting a good thick crop established early in the season, they will make a profit on a good crop; if their stubbles are too thick they will get poor late crops that make a loss. In northern Australia the same elements exist but the risks are different, a situation reflected in the behaviour shown in Figure 25. However, in either setting an unprofitable farmer has little chance of being a good resource manager.
Figure 25: Land preparation methods used by grain farmers.
Source: Connell and Cooper (2000)
The 1999-2000 National Land and Water Resources Audit study on how far Australian landholders are changing their practices to halt and reverse land degradation will provide us with a comprehensive comparative analysis when completed. This study is evaluating the current range of practices across all rural industry sectors, and comparing those with the recommended practices proposed by peak industry bodies, government agencies and research institutions, as described in codes of practice and guideline documents. Land, water, stock, nutrient, pest, and vegetation management practices have been assessed for each region and each industry.
In the last decade, few farmers have not been exposed to government-supported education, training and extension programs aimed at changing land management practices. Many studies show that adult-learning strategies based around group action have been effective in changing attitudes among those who enrol in membership of Landcare and associated programs. Changes in actual practices are slower and more patchy, because they require sustained effort in changing personal behaviour, and sufficient financial resources to adopt new technologies or planning regimes (Barr et al. 2000). Results on the ground are therefore patchy. Across much of Australia, conservation tillage, tree planting, and refencing to conserve waterways and remnant vegetation have been adopted by most farmers, but the actual area affected on each farm may still be relatively small. This occurs because change depends on labour inputs from single-farm operators, and local conditions (such as weeds or pests) may prevent the use of a practice that is, in principle sustainable. In addition sustainable management depends on access to new and sophisticated tools. In parts of regional Australia the adoption of these management tools has also been hampered until the late 1990s by telecommunications difficulties.
Erosion control in forestry and forested lands [L Indicator 1.9B]
While agricultural land use affects by far the largest extent of land, about 20% of Australia is covered with forest, much of it of a sparse, open type. The National Forest Inventory of Australia's definition of 'forest' is somewhat different to that used by the United Nations' Food and Agriculture Organization. The current Australian definition thus includes 112 million hectares of 'sparse forest' that are predominantly of leasehold tenure and often used for grazing purposes. Mallee forests which have more than one stem are also included, contributing a further 15.4 million hectares (Commonwealth of Australia 2001).
'Mallee' is an Aboriginal word for 'water'. Trees were prized for their spreading stems and lignotuber roots, which store large quantities of water.
Source: Murray-Darling Basin Commission
Localised point sources and linear sources of erosion may arise from forestry activities and the unsealed transport routes used in logging. Management practices are now much more tightly regulated in some parts of these industries (e.g. public or multiple-use forests) than they are in agriculture.
In Australia, state and territory governments have primary responsibility for forest management, while the Federal Government coordinates a national approach to environmental and industry development issues. Legislation has developed in a piecemeal way, with gradual extension of legislation to cover more than the simple setting aside areas of state forests for commercial operation, such as water catchment control, conservation and environmental protection. Seventy-four separate Acts that are relevant to forest management across state, territory and commonwealth jurisdictions are listed in the recent State of the Forests Report (National Forest Inventory 1998). Forested regions have also been the focus of significant new arrangements through Regional Forest Agreements (RFAs) in Tasmania, Victoria, south-western Western Australia, coastal New South Wales and parts of south-eastern Queensland (see Figure 26).
Figure 26: Location of Australian forest types and the regions covered by Regional Forest Agreements.
Source: NFI (2000)
All jurisdictions in Australia are signatories to the 1992 National Forest Policy Statement (NFPS). This statement provides the framework within which the governments can cooperatively achieve sustainable management of forests and ensure a balanced use of forests by the community. The policy has broad national goals within regional plans that cover:
- conservation of biodiversity,
- wood production and industry development,
- integrated and coordinated decision-making and management,
- private and public forests and plantations,
- water supply and catchment management,
- tourism and other economic and social opportunities,
- employment, education and training,
- public awareness and involvement, and
- research, development and international responsibilities.
Forest management practices have come under considerable scrutiny in the past three decades, as the result of community concern about environmental impacts from logging and conservation values. Public (or multiple-use) forests have been most affected, and state forestry agencies have increasingly based the management of forests on approved plans required by legislation. Some public forests are now managed by private companies, usually in regions where there are also plantations. Changes in management have been stimulated by Australia's ratification of the International Convention on Biodiversity in 1992, and the development of the NFPS from 1997 onward.
The first formal code of forest practice was enacted in Tasmania in 1985. Codes have since been developed in most states in consultation with scientific experts. They are ratified by state parliaments and there are mechanisms for their application, supervision, monitoring and reporting. Responsibility for ensuring that codes of practice are adhered to lies with the management agency, and timber harvesting contractors and other forest users may be penalised for breaches of the mandatory code.
A range of silvicultural practices are used in forests. For example, fire is generally used as a forest protection measure or after harvesting to promote regeneration, and various degrees of selective logging are associated with different types of forest and terrain. Few public-owned native forests are now clearfelled or subject to mechanical disturbance, though many still allow and require regeneration burns to be carried out after felling. Practices have been codified relative to the forest type (species composition), its life-cycle and ecology. In some cases, fire and canopy removal may be essential to ensure good regeneration. Habitat trees and natural seed stock trees are retained in all forest types that are logged. Rainforests are not logged except in Tasmania, where light felling (>60% canopy retention) is allowed. Further details of logging practices are provided in The State of the Forests (National Forest Inventory, 1998).
Clearfelling, defined as less than 15% of the canopy retained after harvesting, is practised in wet eucalypt forests in Western Australia, Tasmania and Victoria, ash forests in Tasmania, south-eastern coastal eucalypt forest in Victoria, and some open forests in Tasmania. This controversial practice has been widely criticised by environmental groups, but its effects vary considerably depending on site conditions, the structure and composition of the forest, the extent of the methods used to cut and extract logs, and the time for forest renewal. Provided clearfelling retains seed trees and involves only selected coups within a large forest stand, it frequently has only a short-term transient effect on hydrology, microclimate and nutrient cycling until the forest regrows. The general consensus from erosion studies is that clearfelling itself does not contribute much to increased erosion: it is the roads and tracks created for any harvesting operation that are most likely to cause accelerated runoff (Keenan and Kimmins 1993).
Significantly less concern or attention has been paid to forest management and operations in privately owned and leasehold tenures, despite the fact that these forests occupy nearly 70% of forest-designated land, and are used extensively for grazing and sporadically for timber harvesting (National Forest Inventory 1998). In Victoria and Tasmania the codes have been extended to cover logging of private forests.
All public (Crown land) commercial forests are managed to minimise erosion. Spatially this can be assessed accurately only in the areas that provide the majority of the native forest timber production. The most recent estimate of the area available for harvesting is 16.4 million hectares. This comprises 7.2 million hectares of public State managed forest, 0.4 million hectares of leasehold forested lands, 1 million hectares of plantation forest, and 6.7 million hectares of privately owned forested lands, on which episodic clearing and logging operations could expose soil to occasional erosion.
Work being undertaken to respond to the Montral Process is assessing the extent to which codes of practice, assessment and research on erosion are actually in place on these lands. Research related to logging operations has been restricted to catchments that are used for water resources. In such catchments forest harvesting activities such as road construction, and associated disturbances on logged hill slopes are considered to be potential non-point sources of stream water pollution. Most research has been aimed at improving the protection of water quality in forested catchments, but often it has concentrated on before-and-after treatment monitoring, or on small plot-scale operations. International experience demonstrates that activities such as road and track construction are the prime causes of runoff and sediment yield into streams in forest operations (Croke et al. 1997, 1999). Thus the location of such tracks relative to stream patterns, watersheds and hill slope pathways is of critical importance in forest management design, especially in areas of high and intense rainfall.
There is little data for the vast majority of the 156 million hectares of designated sparse and open forested lands. As the predominant land use on these tenures is pastoral grazing rather than forestry.
The most recent information on the impact of forestry practices has come through Australia's contribution to the Montral Process, reporting on the sustainability of temperate and boreal forests. Measures implemented to protect soil and water values will be reported on in 2001. Laws, regulations and institutional frameworks are attempting to report on all forests-multi-purpose, conservation, Crown and private. However, the level of adoption and implementation of recommended practices on privately owned and harvested forests remains limited, except in Tasmania, where all tenures have been included in codes of practice since their inception.
Forestry management codes of practice and regulatory controls have focused largely on the public forests and plantations. Table 12 shows that these areas comprise a minority of forest lands where timber operations may take place.
|Tenure and forest type||Area||% of total wood used for timber, pulp or paper|
|Public native forests||15% of mapped forest extent||75% sawn timber|
|Private and public plantations||1% of mapped forest extent||50% of the wood extracted for processing|
|Private native forests||84% of mapped forest extent||25% sawn timber, 50% of wood for processing|
Actually harvested each year:
0.8% or 10 000 ha from multiple-use forests
16.4 million ha of which 13.3 million ha is public forest
Source: BRS State of the Forest (1998).
Where government responsibilities predominate through tenure obligations, forestry management is reinforced through agreed codes of practice that are thoroughly implemented, assessed and reported on. In privately owned forests the level of required management and reporting on this are both much more variable and may be very limited. In terms of management to reduce accelerated erosion, the most problematic land types are those where forest are open or sparse, and the primary land use (and in many cases tenure) is pastoral grazing. These very large expanses include the areas of woody regrowth and clearing in Queensland as well as other extensive areas of northern savanna woodlands which are subject to very different types of management, including a range of natural and induced fires. 'Forested lands' includes a very wide range of management practice, for erosion control ranging from very good to very poor.
Timber harvesting in native forests inevitably requires the use of large-scale machinery, operating in regions of high rainfall and sloping land where accelerated erosion is a risk.
- Measurements of operating procedures and erosion rates, incorporating the use of 137 Caesium tracers, has confirmed that most sediment generated in forests comes from recently disturbed and compacted surfaces of tracks ('snig lines') in a series of experiments conducted on 22 forest sites in Victoria and NSW. The results showed:
- snig tracks generate on average 7 times as much surface flow and 20 times more sediment than general harvesting areas,
- maximum sediment yields from such tracks were up to 11 tonnes/hectare for a once in a 100 year storm of 30 minutes,
- higher erosion rates occur on granitic soils with coarse sandy soils (e.g: Bombala in NSW, Victoria) than on metamorphic sediments with more clay in the soil, and
- between 40% and 90% of sediment can be trapped and controlled by using cross-banks, culverts and road drains at appropriate spacing.
Forest logging activities cause localised erosion.
Sources: Croke et al. (1997, 1999)
Today the mining industry is probably the most conscientious land user, in terms of environmental management, of any sector in Australia. Much of the impetus has come from the mining industry itself, although government has been a broker and coordinator through the Minerals Council of Australia. The Australian Minerals Industry's Code for Environmental Management is the centrepiece of an ongoing program of industry self-management and improvement that is impressive in its reliance on voluntary compliance and its comprehensive nature.
Australia has several thousand operating open mine sites, ranging in size from such giant activities as the Mt Tom Price iron ore mine in north-western Western Australia to numerous small quarries that supply road metal, lime, and gypsum to local industries. Without the current water and sediment quality standards, all could be localised sources of sediment from runoff, which could contain adsorbed or entrained metals, salts or toxic chemicals. This is all the more likely in many instances because their bare surfaces are frequently composed either of dispersive subsoils or rotted regoliths that erode easily. The progressive introduction of regulatory compliance requirements has reduced this risk to negligible proportions in the majority of current mining operations.
Many mines are located in arid regions where rainfall is infrequent but torrential, and mine site design and management requires careful assessment of the topography, drainage and potential off-site impacts from runoff. In addition, many mines produce acids both from the mineral spoil tips, and from extraction processes, and both air and water emissions can be highly damaging to most life-forms. Past mistakes, a strong research investment, and current sensitivity to community concerns have stimulated the mining industries to mend their own practices in an admirable manner.
All new mines are registered with State or Commonwealth agencies, and must conform to environmental guidelines and submit regular reports on mine site management. After closure of a mine an extensive mine site rehabilitation procedure is required, to return the mine site to a condition which complies with agreed environmental standards (such as return of topsoil, biota, and a full vegetation cover).
The Australian Mining Industry Council developed an initial handbook for industry members in 1991, and an initial code was launched by the Minerals Council of Australia in 1996. A substantially revised code was released in June 2000. Thirty-nine major companies, representing 85% of Australian mineral production, have committed themselves to the new code, all being listed publicly through the Minerals Council of Australia, and on the World Wide Web, and more companies that are signatory to the original code are proceeding with conversion to the new code. Forty-four reports have been published through this scheme to date.
While the code provides a very strong set of prescriptions for operating in a responsible manner to minimise environmental impact, it has nothing to say about abandoned historical mine sites and past degradation resulting from mining and associated processing activities. In many cases private ownership of such mines has lapsed, and responsibility for environmental impact and public safety resides with the government. Nevertheless, the mining industry has set itself a number of challenging restoration projects that aim to overcome such problems as acid leakage from old closed mines that were not operated or designed to manage environmental impact, as at Mt Lyell in Tasmania. This large copper mine was developed during an earlier era when there were no environmental controls. Over 100 million cubic metres of tailings were deposited in the Queen and King rivers and Macquarie Harbour. In this high-rainfall region, water seeping through the mine area gives rise to huge flows of metal-rich acid drainage, with the result that aquatic life in the rivers and estuary has all been killed. An average two tonnes of copper were still discharging into the area from the lease site each day in 1998 (Needham and McBride 1998)!
The Mount Lyell Remediation Research and Demonstration Program, funded jointly by Commonwealth and Tasmanian governments has identified the sources of the acid and copper. Work is in progress to reduce copper and other metal concentrations and treat the acidity, in consultation with community groups, under a Natural Heritage Trust program entitled 'Clean up the King River'. (Riverworks Tasmania reports progress regularly at http://www.ea.gov.au/ssg/remediation/riverw.html)
Management practices to control accelerated erosion and its associated runoff problems differ widely among industries, regions and types of land use. An approximate assessment is provided in Table 13.
|Factor||Pastoral grazing||Rain-fed and irrigated agriculture||Commercial forestry||Open-cast mining|
|Percentage of total land area of Australia||61% 469 million ha in pastoral leases and freehold tenure.||7.7%35 million ha improved grazing, permanent pasture or rotated with 25 million cropping, of which 2 million are irrigated||2%16 million ha total forest estate is 20% (157 million ha) of which 11% (17.6 million ha) is conservation land||0.0013%2 million ha|
|Percentage with effective erosion control (estimated)||unknown-insufficient data||20-75%depending on region and farming system||Probably 85% of commercial forestry; much private forest depends on level of pastoral management||>90% of all large companies. Small operators not well documented|
Mining is now the most highly self-regulating industry, and it must also meet high standards set by relevant government agencies such as Departments of Mines and EPAs. In Australia there are very few non-compliant operations, and all large international companies are keenly aware of the importance of community environmental programs in their public relations. Some companies, such as WMC and Alcoa, have contributed substantially to local community activities in catchment management well beyond the confines of their own mining responsibilities.
Forestry operations have the potential to create significant soil erosion unless they are carefully managed, as they are frequently carried out on sloping lands in high-rainfall environments. In general, where harvesting operations comply with relevant harvesting and erosion controls there is a relatively small effect on erosion, and the increase in runoff from logged areas is generally small in well-managed modern operations which retain a full surface cover of brush and litter even in clearfelling operations.
Farmers at a crop management field day.
Source: A Hamblin
Our knowledge about what happens in much of the forest estate is still patchy, but will shortly be much greater as reporting on Montral Process indicators is compiled in 2001-2. Bearing in mind that much of the private and leasehold land on which 'forest' occurs is designated for or used for grazing, such forested and wooded lands must be considered in the light of their grazing management. Only 6.6% of all leasehold, private and Crown forest lands are actually available for harvesting. The rest does not contain enough commercial species.
In agricultural areas the record is much more patchy. Some intensive cropping industries have a good level of erosion control, such as the northern and central sugar cane areas of Queensland that practise green-trash harvesting, and horticultural or viticultural irrigated blocks with permanent pasture or green-manure crops. All state and territory primary industry agencies have developed guidelines for sound management (SCARM 1998), and actively promote these practices through demonstration and training courses.
However, there are still large areas of cropping where only partial erosion control is practised, such as stubble retention in southern grain-growing areas. Grazing practices are highly variable and across much of the country are good only when rainfall is good, stocking levels are low or both. Much of the most degraded rangeland never recovers a full cover of understorey vegetation because there is a constant grazing pressure. In some cases (Western Australia and South Australia) limited duration and flexible tenures and monitoring of management standards provides some measure of control. In others (notably Queensland and the Western Division in New South Wales), leases are virtually indistinguishable from freehold, yet allow only pastoralism to be practised, creating an inflexible system with little opportunity for aggregation of properties or diversity of land use.
Comparisons across various primary industries prompt the question: 'Are voluntary environmental management practices sufficient to control accelerated erosion and reduce surface soil loss on agricultural lands?'
All indications are that a mixture of government regulation and inspection is required in addition to industry self-regulation to achieve lasting improvement. Miners and, increasingly, foresters operate under stringent guidelines, but any suggestion that farmers should do the same is met with concern. Voluntary schemes such as Landcare have not, in up to 10 years of operation, managed to recruit all landholders, and there are still many examples of good practices coexisting with poor practices in the same district. At present there are few financial or other business incentives that provide sufficient reward or encouragement to draw in all landholders, other than the feel-good ethic of those landholders who are committed to careful environmental management and those non-landholders who advocate sustainable land management.
As the reasons for non-participation include lack of landholder funds to implement change, there are serious questions about whether current levels of combined government and private investment can achieve any significant change in the foreseeable future. The National Farmers Federation and Australian Conservation Foundation have recently joined forces to commission estimates of the annual cost of degradation in rural landscapes. They estimate that erosion alone costs $80 million per year in infrastructure repairs, but a much larger $450 million in water quality contamination. They argue for a massively increased public contribution to achieve sustainability targets.