Forestry

This content is currently under review. Statistics date from 1990.

Forests can be defined in many ways, largely depending on the objectives and perceptions of those making the definitions. The following definition is that used in the National Forest Policy Statement (CA 1992):

An area that is dominated by trees having usually a single stem and a mature or potentially mature stand height exceeding 5 metres, and with existing or potential projective cover of over story strata about equal to or greater than 30 per cent*. This definition includes Australia's diverse native forest and plantations, regardless of age. It is also sufficiently broad to encompass areas of trees that are sometimes described as woodlands.

A distinction is made between forests and woodlands essentially on the basis of crown or canopy cover, forests having greater than a 50 per cent cover and woodland being in the 20 to 50 per cent range. However, the terms 'forest' and 'woodland' are not always used in such a specific way, and many areas regarded as woodlands under this definition are commonly termed forests.

Forests are incredibly diverse, dynamic and complex ecosystems, providing habitats for flora and fauna. They contain valuable renewable resources, especially timber, and they provide a variety of important services, such as water catchment, recreation, and aesthetic value and appeal. They satisfy a great variety of needs for large numbers of people.

* : The 30 percent cover of overstorey is equivalent to the 50 per cent crown cover figure used in the National Forest Inventory.

Forests in the Murray-Darling Basin

On the basis of the definition given above, there are 2.03 million hectares of forests and 16.56 million hectares of woodland in the Murray-Darling Basin (Figure 1). However, it should be noted that many of the areas thus classified as woodland are commonly referred to as forests. It should also be noted that much of the Basin's native forests and woodland are in national parks and other reserves and so not available for timber production, while large areas of state forests are also reserved for conservation (see National Parks and other Reserves).

Figure 1: Forest and woodland in the MDB

No data are available on the overall value of forestry production in the Murray-Darling Basin. The only indicators are provided by two of the categories of manufacturing industry (see Manufacturing Industry). Most useful is the 'Wood, wood products and furniture' group, which had a turnover of $601.1 million in 1991-92. Of less value is 'Paper, paper products and publishing', with a figure of $617.0 million, though a significant part of this would be accounted for by the newsprint mill at Albury.

In terms of production, most of the native eucalyptus forests are of low productivity, which explains why the Basin accounts for only 5 per cent of Australia's total eucalypt timber. Other factors are the distance to markets and the absence of large scale wood chipping operations. There are, however, three exceptions. The first is the native white cypress pine (Callitris glauca). With 78 per cent of Australia's area and 91 per cent of the production, the Basin is the major source of this white ant resistant timber. The main areas are the Pilliga State Forest, to the north of Coonabarabran, and a number of areas in the Queensland portion of the Basin (including the Barakula State Forest north of Chinchilla), where it is the most important timber. The second exception are the ash forests, primarily alpine ash (Eucalyptus delegatensis), the only Class I productivity Eucalyptus forests in the Basin, located in some of the higher parts of south-east New South Wales and north-east Victoria. The third exception is the river red gum (Eucalyptus camaldulensis Dehn.), the main areas of which are to be found along the Murray in the Barmah-Millewa and Gunbower-Perricoota forests.

The prime function of state forests and most managed forests is timber production. It is likely that timber production from native forests will decline significantly over coming years, though that from cypress pine should be maintained. The creation of additional national parks in New South Wales will add to the decline (see National Parks and other Reserves). However, the forests also have other functions, including providing habitats for native fauna, and flora preservation, as under the NSW Native Forest Preservation Program through designated Flora Reserves. Forests also provide grazing for livestock, water catchment, and are important for honey production. The native forests also have significant value for recreation.

In addition to the native forests, there are close to 300,000 hectares of exotic coniferous plantations in the Basin, including 245,000 hectares in the New South Wales portion. These account for a significant proportion of Australia's area of coniferous plantations and production of softwood timber. The main species is Pinus radiata, which makes up over 90 per cent of the total area, with new planting being of genetically-improved stock. The largest growing regions are the Tumut-Batlow-Tumbarumba and Oberon-Bathurst-Orange districts in New South Wales, the Ovens, Kiewa, Koetong and Benalla-Mansfield districts in Victoria, and a number of districts in south-east Queensland (which provide a significant proportion of that State's timber production). There are many new plantings in all districts, on both state and private land. Other areas include the ACT and Queanbeyan, Carcoar, and the Glen Innes district of New England. The plantations have been concentrated in a number of selected areas in order to provide the required support services. In turn, they provide the bases for industrial activities both within the Basin and beyond (see Manufacturing Industry).

The area of softwood plantations is small in comparison to that of native forests and woodland, but in terms of timber production, the reverse is the case. Further, as many Pinus radiata plantations are not yet mature, softwood production will increase dramatically over the coming years. Only the best Class I native forests can match the productivity of the exotic softwood plantations.

Over recent years, the expansion of softwood plantations has been paralleled - though thus far on a much smaller scale - by extensive tree planting programs on farms, especially of native hardwoods. Many of the planting have been undertaken by individual farmers in response to a range of soil and land degradation problems, especially in dryland and irrigated areas affected by highly saline watertables. More recently, there has been increasing support for such plantings by various federal and state government agencies, such as the Federal Government's 'Farm Forestry Program', Greening Australia's 'River Murray Corridors of Green' program, and the 'Trees for Profit' program in Victoria and southern New South Wales. A number of plantations have already been established, such as at Deniliquin, Mildura and Dubbo, with others under consideration. In NSW, State Forests are establishing eucalypt plantations on private land as joint ventures with farmers, while there are indications of growing interest in large-scale plantings of hardwoods by private entrepreneurs. NSW State Forests are also becoming involved in the management of native forests on private land, as in the Riverina.

Figure 2 Tree loss in the MDB (source: Brett 1993)

However, it does not seem possible that there can be a significant closing of the gap between present-day tree numbers in the Murray-Darling Basin of some 8 billion and the estimated 20-23 billion when European settlers arrived (Figure 2) (Brett 1993; Carnahan et al. 1990), even with the 'One Billion Trees' program: "The replanting of 12-15 billion trees over a wide area is unlikely due to high costs and current land uses.  Strategic planting based on significant impacts on local and regional water balances seems the most useful approach" (Walker et al. 1993). There also has to be a halt to further indiscriminate clearing of native trees and forests (see Land and its Changing Use). However, the creation of national parks that result in the elimination of sawmilling, as in the case of the small town of Coolah, seemingly without adequate investigations, consultation, or the consideration of a compromise, is an equally undesirable situation (The Australian, December 20, 1995).

Case studies

Tumut and district

In the Tumut-Batlow-Tumbarumba area, there are some 118,000 hectares of State Forests of New South Wales pine plantations (93 per cent Pinus radiata), plus over 20,000 hectares of private plantations (one company owns over 8,400 hectares) (Figure 3).

Figure 3 Forest in the Tumut district (source: NSW State Forests)

The State Forests' Bondo Nursery produces 4 million seedlings each year. There are also hardwoods in the Bago, Maragle and Buccleugh State Forests, including 12,000 hectares of alpine ash (Eucalyptus delegatensis) in the 44,000 hectares Bago State Forest (plus 1,600 hectares in Maragle), the most northerly locations for alpine ash, a fast growing, high quality timber. As outlined in the Manufacturing Industry page, the plantations and hardwood forests provide over 500,000 cubic metres of timber a year for a number of saw mills and industries in Tumut and other locations. The State Forests also cater for tourist and recreation activities.

Logging began in the area in the 1870s, while the first softwoods were planted in 1921, when various trial plantings were carried out. Pinus radiata proved to be most suited to the area's soils and climatic conditions. Much of the recent plantings have been on former farmland.

Pilliga State Forest

The Pilliga, located north of Coonabarabran, is the only large area in the Murray-Darling Basin that has naturally regenerated from sparse open woodland to forest over the period of European settlement. This is essentially due to the elimination of Aboriginal burning and reduced grazing. By the early 1900s, the elimination of burning was resulting in very dense growths of the pine and in order to bring about the proper management of the area, the State Forests were established. Now the largest expanse of inland plains forest in Australia, it is a highly modified forest environment (Rolls 1981; FCNSW 1988; Rolls 1997) (Figure 4).

Figure 4 Pilliga State Forests (source: Rolls 1997)

The main species is the native white cypress pine (Callitris glauca), occurring over 80 per cent of the Pilliga Management Area which covers over 421,000 hectares. The significance of white cypress pine is its resistance to white ants, making it a valued construction timber, especially for floorboards. Some 53,000 cubic metres are cut each year. Other species in the area include narrow leaved ironbark (which is used for railway sleepers, fence posts and other hardwood products). In order to maintain production of cypress pine timber, new production areas may need to be established. The bushfires of late 1997 resulted in significant losses of white cypress and eucalypts over 143,000 hectares of the area.

The forests are also important for grazing, beekeeping, as a source of broombrush (for fencing), recreation, and their historical sites. The Pilliga Nature Reserve, which is included in the Management Area, represents one of the major plant and animal communities in the Central West of New South Wales.

Barmah-Millewa Forests

Riverine forests are a feature of the Murray, its tributaries and its many associated waterways and wetlands (Bren 1991; Binnington et al. 1994). The principle tree species is the River red gum (Eucalyptus camaldulensis Dehn.). The most widely distributed of the Eucalypts and present in all mainland states, some trees are up to 500 years old and 40 metres high. The major concentrations are on the Riverine Plain, especially the Barmah-Millewa Forests (Figure 5).

Figure 5 Barmah-Millewa and other Riverine Plain forests

Covering some 70,000 hectares, it is the largest stand of river red gum in the world, with a further 44,500 hectares on the nearby floodplains of the Murray and Edward Rivers. Other associated species are the more open woodlands of grey, yellow and black box.

The Barmah-Millewa Forest is a complex ecosystem, with more than 400 species, and in addition to its importance as a forest, it is also among Australia's most important wetlands. It is listed under the Ramsar Convention as a wetland of international significance, being a breeding ground for waterbirds, including the sacred straw-necked ibis. Some 8,000 hectares are in a State Park on the Victorian side of the River, with much of the remainder in state forests. These are managed for various uses, including the flora and fauna (especially the waterbirds), native fish, bee keeping, grazing, their scientific value, and recreation, as well as timber and charcoal production. Timber is used for many purposes, including railway sleepers, construction purposes (including bridges), furniture, etc. Some years ago, the total value of forest products from Victoria's Barmah and Gunbower Forests was estimated at over $6.6 million per annum (Parsons et al 1987), while overall values are now clearly much larger (Table 1) (Binnington et al. 1994).

Aboriginal occupation of the forests dates back at least 40,000 years, with many indications of their occupation, such as carved trees (for canoes and dishes), fish traps, middens, ceremonial grounds, and burial grounds. The forest continues to be of much significance to the local Aboriginals.

The various phases of European activity have left their marks on the Barmah-Millewa Forest. Grazing has given parts of the forest a parkland landscape, though not without its impact on the trees and other vegetation. Reminders of the early logging periods are seen in the remains of barges, wharves and punts. More recently, have come the recreational and educational amenities and evidence of management for the sustainability of the forests.

Given the region's climate, and especially the rainfall of some 450 mm per annum, the trees are critically dependent on the rivers. Not only that, they require periodic flooding. Under natural conditions, the forests were flooded almost every winter and spring. However, since the construction of the first Hume Dam in 1934, there have been reduced winter and spring flows and increases in summer and autumn flows, as well as a reduction in the frequency and duration of winter and spring floods. The impacts of these changes on the trees, other vegetation and fauna have been significant and they have been accentuated since the construction of Dartmouth Dam. Some trees have died, or are dying, from too much water, others from too little, while there has been substantial decline in growth and regeneration within the forests.

Because of the damage being done to the health of the trees and the integrity of the Forest, a Water Management Plan was endorsed by the Murray-Darling Basin Commission in 1993 (MDBC 1992; MDBC 1994). A specific water allocation of 100,000 ml per year has been made available, to be released according to the Forest's environmental requirements. The managed flooding will attempt to replicate as closely as possible the pre-1934 natural conditions. Only about 10 per cent of the water entering the forest is taken up, the remainder leaving the forest in a much cleaner condition than when it entered.

Woodlands

As can be seen from the map (Figure 1), there are significant areas of woodland in all parts of the Murray-Darling Basin. They are made up of many different species, such as the Poplar box (Eucalyptus populnea) that cover much of the northern and western parts of the Basin, Mulga (Acacia aneura and related species) and Mallee. "The term 'mallee' describes eucalypts with a multi-stemmed habit and the vegetation dominated by them" (Carnahan et al. 1990, 36). There are over 100 mallee species. Mallee extends over large areas in north-west Victoria, south-west New South Wales and adjoining areas of South Australia. During the period of the paddle-steamers and steam-powered pumps for the irrigation areas, the mallee roots and trunks were the main source of fuel. Mallee continues to be a source of wood for domestic fuel in some areas, while the blue mallee (E. polybractea) is a source of oils. Broombrush (Melaleuca uncinata), which grows in association with mallee, is harvested in some licensed areas for fencing (Noble et al. 1990).

Conclusion

Forests and woodlands occupy a critical place in the ecology and economy of the Murray-Darling Basin. The realisation of the full extent of the reduction in tree numbers since European settlement and the consequences of this, has resulted in much tree planting activity over recent trees. This must be continued and expanded, not least as a means of helping to stem and reduce land and water degradation, such as lowering watertable levels. In the medium to longer term, these trees will provide a valuable source of significant quantities of timber. Not only will this reduce the pressures on remaining natural forests, it will be an important addition to the economies of parts of the Murray-Darling Basin.

References

Binnington, K. et al. (1994): Australian Forest Profiles. 3: River Red Gum. National Forest Inventory, Bureau of Resource Sciences, Canberra.

Bren, L.J. (1991): "River red gum forests:. pp. in The Murray, edited by N. Mackay and D. Eastburn. Murray-Darling Basin Commission, Canberra.

Brett, D. (1993): "Restoring the Murray-Darling Basin". pp. 30-35 in Land Care: science in action, edited by B. Morris. CSIRO Publications, Canberra.

CA (1992): National Forest Policy Statement: a new focus for Australia's forests. Commonwealth of Australia, Canberra.

Carnahan, J. et al. (1990): Atlas of Australian Resources, Third Series, Volume 6: Vegetation. Australian Surveying and Land Information Group, Canberra.

FCNSW (1988): Pilliga Forests: managing your State Forests. Forestry Commission of New South Wales, Sydney.

MDBC (1992): Watering the Barmah-Millewa Red Gum Forest: issues paper. Murray-Darling Basin Commission, Canberra.

MDBC (1994): Murray-Darling Basin Commission: annual report 1993-94. Murray-Darling Basin Commission, Canberra.

Noble, J.C. et al. (Editors)(1990): The Mallee Lands: a conservation perspective. CSIRO Publications, Melbourne.

Parsons, M. et al (1987): "Riverine forests of the Central Murray Valley". pp. 343-359 in Forest Management in Australia: 1987 Conference of the Institute of Foresters of Australia: proceedings. Institute of Foresters of Australia, Perth.

Rolls, E. (1981): A Million Wild Acres: 200 years of man and an Australian Forest. Thomas Nelson Australia, Melbourne.

Rolls, E. (1997): The Pilliga. Murray-Darling Basin Commission, Canberra.

Walker, J. et al (1993): "Ecohydrological changes in the Murray-Darling Basin. The number of trees cleared over two centuries". Journal of Applied Ecology, 30, 265-273.

Table 1 Recent annual production from river red gum forests in New South Wales and Victoria* (source: Binnington 1994, 6)

*Excludes freehold land in Victoria