Australian forest profiles: Acacia

The genus Acacia occurs naturally on all continents except Europe and Antarctica and contains more than 1,500 species. Australia has around 955 species, making it the nation’s largest genus of flowering plants. The genus is remarkably varied in appearance, habit and location, encompassing species with small creeping forms and trees that can grow as tall as 30 metres. Australia has more than 50 species of forest-forming acacias.1

Acacias became known as wattles in Australia because their branches were used to build huts with what the early British settlers called the ‘wattle and daub’ method. This involved weaving acacia branches among stakes to create a frame that could be plastered with mud.

Many acacias produce spectacular golden flowers and are a conspicuous feature of the Australian landscape. An acacia was one of the first Australian plants collected by Europeans. 

Trees without leaves

Acacias produce leaves of great variety. Often, however, what look like leaves are not really leaves at all but phyllodes — flattened leaf stalks — that look and function like leaves. Some phyllodes are large — up to 30 centimetres long; others are so small they are hard to see. Some stems, such as those of A. glaucoptera, have distinctive wide wings with tiny phyllodes. Several acacias have bipinnate (fern-like) leaves, made up of a large number of small leaflets (pinnules) along a central stalk.

 

Values and uses

Wood

The arts and craft industry makes substantial use of the attractive timbers of some Acacia species, particularly blackwood. In the past, black wattle (Acacia mearnsii), silver wattle (A. dealbata) and brown salwood (A. celsa) have been harvested for their timber or to produce paper pulp.

Acacias have also been harvested and used for poles, posts and rails and for small-scale wood-turning. Some, such as lancewood, burn slowly and evenly and are valued as firewood.

Plantations of Australian acacias have been established in more than 70 countries. Mangium (A. mangium) occurs naturally in Queensland, Papua New Guinea and eastern Indonesia and is a major plantation species in tropical countries as well as in the Northern Territory. Queensland’s natural populations of this species therefore constitute a valuable genetic resource for the global plantation industry.

Mangium comprises 97% of Australia’s acacia plantations. The remaining plantings in Australia comprise a few hundred hectares of A. decurrens and A. melanoxylon and even smaller areas of 15 other species.

Mangium plantations Melville Island

With a land area of 5 788 km2, Melville Island is Australia’s second largest island after Tasmania and the larger of the two Tiwi Islands north of Darwin. The entire island is Aboriginal freehold land. Until recently, it remained mostly untouched by large-scale modern development, the exception being a small area of trial plantations and a somewhat larger area of exotic Pinus caribaea (about 2 200 hectares), which was planted in the period 1975–1997. Relatively high rainfall (ranging from 1 400 mm/yr in the east to 2 000 mm/yr in the northwest), warm to hot temperatures (16–29˚ in July to 25–35˚C in November), gentle terrain, low elevation (<102 m above sea level) and deep red and yellow sandy soils have attracted the establishment of short-rotation plantation forestry using Acacia mangium. First established in the late 1990s, these plantations have now expanded to more than 20 000 hectares.

 

Environmental

Because of their wide distribution, acacia forests are important for biodiversity conservation and the maintenance of ecosystem processes. The Brigalow Belt in northern New South Wales and Queensland, for example, supports at least 148 species of reptiles, 13 of which are rare or endangered, and 328 species of birds, 24 of which are threatened. Mature brigalow constitutes the sole food source of the vulnerable northern imperial hairstreak butterfly (Jalmenus evagoras subspecies eubulus), which is restricted to about 30 locations in the Brigalow.

Indigenous uses

Indigenous people have long used acacias for fuel, medicine, musical instruments (such as clap-sticks), tools and weapons (notably boomerangs and spearheads), and in ritual practices. The seeds of about 50 Australian dry-zone Acacia species are a traditional food. Acacia seeds were ground into flour to make cakes. Witchetty grubs, an important source of food, can be found under the bark and in the roots of some species. Indigenous knowledge of acacias is an invaluable guide to their potential wider use.

Other uses

Acacia forests supply industries based on cut flowers and oils and are also commonly used in land rehabilitation. Mulga is an important fodder tree across semi-arid northern Australia, sustaining stock in times of drought. Species such as black wattle were once used in Australia as a source of tannin for treating leather and are still used for this purpose overseas. Acacia seeds have been developed as a bush food used to flavour cakes, biscuits and ice cream.

Nitrogen Fixation

Acacias fix atmospheric nitrogen with the aid of symbiotic bacteria (rhizobia) that live in nodules on the roots. While this process occurs in nature, a wattle seed inoculant, Wattle GrowTM, has been developed to improve survival of planted acacias and reduce the amount of seed required to vegetate a given area. Containing four elite strains of Bradyrhizobium, it is effective on a range of wattle species used for revegetation in southeastern Australia.

Australian forest profiles: Callitris

Australian forest profiles: Callitris

The Callitris genus occurs only in Australia (14 species) and New Caledonia (two species). This distribution reflects the fact that Australia and New Caledonia were once part of a single landmass, the ancient super-continent of Gondwana.

Callitris trees are commonly called cypress pines because of their resemblance to northern hemisphere cypresses. They are not true pines, although they are conifers. The taxonomy of the genus was revised in 2005–06.

Australia has more than 2.5 million hectares of callitris forest, which is 2% of its total forest cover.1

In the absence of fire and grazing, callitris advances into eucalypt woodland (left). Fire reverses this tendency by killing most of the young encroaching callitris (middle). The small group of callitris shown on the right has survived in an upland rocky area that has insufficient ground cover to carry a fire.

Coastal cypress pine forest in the New South Wales north coast bioregion – proposed endangered ecological community listing

Coastal cypress pine forest is found typically on the inland side of coastal sand plains, north from the Angourie area on the far north coast of New South Wales, including the local government areas of Tweed, Byron, Ballina, and Richmond Valley. The community typically comprises a mixture of eucalypts, acacias, banksias and/or rainforest trees. Some stands of the community that have been partially cleared in the past are now reduced to scattered trees. Fires have also influenced stand structure, as the dominant tree species, Callitris columellaris, is generally killed when burnt. Post-fire regeneration of the community may therefore only have the structure of a shrubland or heathland and no longer be mapped as forest.

Estimates based on field observations of old remnant trees in cleared land around the remaining stands suggest that the geographic extent of the community has declined by more than 77%. The actual reduction in geographic distribution is likely to be greater than that, since any stands that were totally removed could not be included in this method of assessment. Small-scale clearing continues to threaten the community, mainly as a result of coastal development and associated roads. In the past 20 years, fragmentation of the community has increased as a result of clearing for tea tree plantations, caravan parks, road construction and associated quarrying. The integrity and survival of remaining small and isolated stands of the community are impaired by the small population sizes of the component species, disruption of pollination and dispersal of fruits and seeds, and likely reductions in the genetic diversity of isolated populations. Other threats include habitat degradation as a result of trampling by people and livestock, rubbish dumping, and weed invasion.

A number of threatened species have been recorded in coastal cypress pine forest or associated vegetation, including Acronychia littoralis (scented acronychia), Archidendron hendersonii (white lace flower), Geodorum densiflorum (pink nodding orchid) and Drynaria rigidula (basket fern).

Where are Australia’s callitris forests?

Australia’s 2.6 million hectares of callitris forests are components of many Australian ecosystems, from the arid tropics to the Australian Alps (Figure 1). The most common species is white cypress pine. New South Wales has 59% of the area of callitris forest, Queensland 23% (Table 2).

Changes in fire frequency and land management since European settlement have allowed white cypress pine forests to expand in extent. Woodlands and open forests of white cypress pine and other callitris species grow in Queensland, New South Wales and South Australia. Tall open forests of Port Jackson pine (C. rhomboidea) grow in Tasmania and there are open forests of Rottnest Island pine (C. preissii) in coastal Western Australia and South Australia. Woodlands dominated by black cypress pine (C. endlicheri) and family pine (C. verrucosa) grow in localised areas in Queensland, New South Wales and the Australian Capital Territory. Callitris oblonga is the only member of the genus adapted to riverine habitats, but it can also grow on very dry sites.

 

Ownership and management

Most callitris forests (83%) are found on leasehold and private land. About 7% is designated as multiple-use public forest (in which one possible use is wood production).

Values and uses

Wood

A large number of small local sawmills once relied on callitris forests for their timber supply. Many of these mills have now closed as much of the cypress pine forest devoted to timber production has been incorporated into conservation areas.

Nevertheless, Callitris is still the second most important genus in the native forest-based timber industry after Eucalyptus and is the only significant softwood timber harvested commercially in native forests. In 2007, 58 000 m3 of cypress pine sawlogs were harvested in New South Wales and, in 2004–05, 138 000 m3 were harvested in Queensland.

The strength and durability of the timber are important assets. It can resist decay and termites for up to 50 years and like all softwoods is immune to lyctid borer attack. The timber has been used widely for in-ground applications such as house stumps, fence posts and telephone poles, as well as for flooring and furniture. Callitris makes excellent kindling wood but burns too hot and too rapidly for use in domestic stoves and heaters.

Environmental

Fauna diversity is high in mixed eucalypt/callitris forest but extremely low in pure callitris stands. A survey in mixed eucalypt/callitris forest in the Barakula State Forest (south Queensland) found 127

native animal species, including 84 birds, 6 bats, 19 reptiles and two rare or threatened species (the yellow-bellied glider, Petaurus australis and the yellow-tufted honeyeater, Lichenostomus melanops).

Indigenous uses

Callitris forests are an important part of the culture of Australia’s Indigenous people and contain many sites of significant cultural value. Indigenous people have traditionally used northern cypress pine (also called blue cypress pine, now included in Callitris columellaris) wood for firewood and torches, as well as for the manufacture of spears, spear throwers, ceremonial objects, paddles and music sticks. Resin is used to make glue while the cones, bark, leaves and ash are components in various medicines. Callitris bark is used to make rope and to repel mosquitoes and, in Arnhem Land, to make waist belts. The Walbiri people of Central Australia make implements from the wood of the white cypress pine.

Other uses

Resin from the white cypress pine has been used as a substitute for sandarac resin, a raw material for specialist varnishes, and as incense. Blue cypress pine produces an oil suitable for aromatherapy; most production is derived from plantations rather than native callitris forests. Large areas of callitris forests are also used for grazing and beekeeping.

The Pilga Scrub

The Pilliga Scrub is a vast woodland in western New South Wales characterised by native white cypress pine and ironbark forests, spring flowers and abundant fauna. Pilliga is an Aboriginal word meaning swamp oak. The name was adopted in the mid-1800s for one of the original grazing properties, near where the town of Pilliga now stands. Occupying about 500 000 hectares between the Namoi River in the north and the Warrumbungle Ranges in the south, the Pilliga comprises the largest remaining area of native forest in New South Wales west of the Great Dividing Range.

The current forest structure reflects the history of settlement in the region, following many thousands of years of Aboriginal occupation. When European settlers arrived in the early 1830s they established grazing runs throughout the forests, which then comprised well-scattered large trees over a grassy understorey. Burning by Aborigines and grazing by kangaroo rats (Notomys spp.) had, up to then, kept the forest floor relatively free of regeneration.

The introduction of cattle and sheep by settlers resulted in significant ecological changes. The soils deteriorated and the mix and grazing quality of the native grasses changed. The kangaroo rats were displaced. A prolonged drought during the 1870s and early 1880s caused most of the grazing runs to be abandoned. Then, during the late 1880s and early 1890s, there was a succession of good seasons, which, in the absence of grazing pressure and regular burning, led to the massive regeneration of native cypress and eucalypts across much of the Pilliga.

The introduction and spread of rabbits throughout the area in the early 1900s reduced the potential for regeneration in the Pilliga until the introduction of the rabbit control agent myxomatosis in the 1950s. With the consequent decline of the rabbits, a new wave of young cypress and eucalypt seedlings was able to establish and grow.

The success of cypress regeneration represents a management challenge. Many hundreds of seedlings and saplings can be present on a single hectare, and competition among them can result in ‘lock-ups’ – where growth is brought to a standstill as available light, moisture and nutrients are expended solely on survival. In areas managed for sawlog supply, these stands must be thinned, a task that is carried out by workers using brushcutters.

The cypress regeneration that occurred in the late 1800s forms the basis of the timber industry operating in the Pilliga today. The 1950s regeneration and subsequent growth is being managed to provide a sustainable yield of timber into the future.

The New South Wales government, in its Western Woodlands decision, gazetted extensive new Community Conservation Areas (CCAs) under the Brigalow and Nandewar Community Conservation Act 2005, affecting the Brigalow Belt and Nandewar regions from Dubbo to the Queensland border. This added 352 000 hectares of land to nature conservation reserves, including the Pilliga, Goonoo, Terry Hie Hie and Bebo forests. Under the Act:

348 000 hectares of former state forest were included in the CCAs CCAs were created with four defined zones

o Zone 1: Conservation and recreation o Zone 2: Conservation and Aboriginal culture o Zone 3: Conservation, recreation and mineral exploration (mining and gas) o Zone 4: Forestry, recreation and mineral extraction.

A Community Conservation Council was established to oversee the CCAs and, in turn, will be advised by three community-based advisory committees based on catchment management areas

Timber industry participants have 20-year wood supply agreements and receive development assistance funds

New visitor infrastructure in the CCAs is being built with the assistance of a capital investment fund

A job creation package is being implemented for the non commercial thinning of productive cypress pine forests.

References and further reading

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Melbourne.

Council of Heads of Australasian Herbaria (CHAH) (2006). Australian Plant Census (see website address below).

Farjon A (2005). A Monograph of Cupressaceae and Sciadopitys, Royal Botanic Gardens, Kew, UK.

Hill K (1998). Cupressaceae. Flora of Australia, Volume 48 (Ferns, Gymnosperms and Allied Groups), CSIRO Publishing, Melbourne.

MIG (Montreal Process Implementation Group for Australia) (2008). Australia’s State of the Forests Report 2008, Bureau of Rural Sciences, Canberra.

NFI (National Forest Inventory) (2003). Australia’s State of the Forests Report 2003, Bureau of Rural Sciences, Canberra.

State Forests NSW and North West Catchment Management Committee (1997). Managing Cypress Pine on Your Property, State Forests NSW, Sydney.

Websites

www.anbg.gov.au/chah/apc/index.htmlwww.daff.gov.au/forestsaustraliawww.hardwood.timber.net.au/species/cypresspine.htm

Footnotes

1 Australia’s definition of forest is ‘an area dominated by trees having usually a single stem and a mature or potentially mature height exceeding 2 m and with an existing or potential crown cover of overstorey strata about equal to or greater than 20%.’

Australian forest profiles: Casuarina

The family Casuarinaceae occurs naturally in Australia, Southeast Asia and the Pacific and comprises four genera and 90 species. Australia has 66 species in three genera: six in Casuarina, 59 in Allocasuarina and one in Gymnostoma. Commonly called she-oaks (and sometimes oaks) because of the similarity of their timber to that of European oaks, casuarinas are a distinctive part of many Australian coastal and riverine landscapes.

The word ‘casuarina’ is derived from the Malay word for cassowary, kasuari, and is a reference to the similarity of the tree’s drooping branches to the feathers of the bird. Casuarinas also bear a resemblance to pine trees, with needle-like foliage and woody fruits. The foliage, however, is not composed of true leaves but rather of green, jointed branchlets that function like leaves. The true leaves are tiny, tooth-like structures protruding from around the top of each joint.

Only some casuarina species form forest communities1; others are too short or sparsely distributed to be classified as forest. Most casuarina forests are low in height, sometimes with a dense, shrubby understorey. The tallest casuarina forests occur along rivers, where trees can grow to more than 20 metres.

Casuarina forests occur as woodlands or open forests over more than 2.2 million hectares and make up about 1.5% of Australia’s total forest area.

Table 1 shows that the total area of casuarina forest increased by nearly a quarter of a million hectares between 2003 and 2008, mainly as a result of improved mapping in the Northern Territory.

The table also shows that more than 800 000 hectares of casuarina forest classified in 2003 in an ‘unknown’ crown cover class has been reclassified as either woodland or open forest, and that a large area of forest previously classified as open forest is now classified as woodland.

Where are Australia’s casuarina forests?

Casuarina forests occur in all states and territories of Australia (Table 2). Its largest expanse occurs in a band from the semi-arid zone in South Australia through western New South Wales and into Queensland (Figure 1). Significant forests are also found in coastal New South Wales. Belah (Casuarina cristata) forests have the widest distribution, growing in habitats ranging from stony slopes to heavy clay soils.

Common inland species include belah and river she-oak (C. cunninghamiana), which often occur in association with acacias and eucalypts. Coast she-oak (C. equisetifolia) occurs in pure stands on coastal fore-dunes in eastern Australia and, in less exposed sites, also in association with coastal banksias. Pure stands of the rock she-oak (Allocasuarina huegeliana) are found on granite soils and outcrops in Western Australia. Because it is more resistant than local eucalypts to drought, drooping she-oak (A. verticillata) forms pure stands on very dry sites in Tasmania.

Figure 1: Casuarina forest distribution, 2008

Table 1: Area of casuarina forest, by crown cover, 2003 and 2008 (’000 hectares)

Woodland Open Closed Unknown crown cover Total

Casuarina 2003 359 871 0 809 2,039

Casuarina 2008 2,082 191 0 0 2,274

Note: Crown cover is the area of ground covered by tree canopies, ignoring overlaps and gaps within individual canopies. It is usually measured from above using aerial photographs or other remote sensing imagery. In Australia, woodland has a crown cover of 20–50%, open forest a crown cover of 50–80%, and closed forest a crown cover of greater than 80%.Sources: NFI (2003), MIG (2008).

Ownership and management

New South Wales contains 52% of Australia’s casuarina forests, South Australia 30% and Victoria 6% (Table 2). About 45% of the casuarina forest estate occurs on leasehold land, 37% in nature conservation reserves and 13% on private land. Less than 5% is located in multiple-use public forests or on other crown land.

Table 2: Tenure of casuarina forest, by state and territory, 2008 (hectares)

Tenure ACT NSW NT Qld SA Tas. Vic. WA Australia

Leasehold land 42 918,135 34,408 20,165 13,427 0 0 20,036 1,006,213

Multiple-use forests 0 8,362 0 2,575 0 0 19,988 0 30,925

Nature conservation reserves 207 109,850 15 3,486 629,681 619 71,641 8,747 824,246

Other crown land 0 20,685 3,986 960 5,273 97 3,033 35,497 69,531

Private land 0 104,608 75,079 28,801 21,470 700 36,506 18,093 285,257

Unresolved tenure 0 5,922 284 5,366 1,078 0 0 0 12 650

Total 249 1,167,562 113,772 61,353 670,929 1,416 131,168 82,373 2,228,822

Note: Totals may not tally due to rounding. The six forest tenure categories above are defined at MIG (2008, ppxvii–xviii).Source: NFI (2003), MIG (2008)

 

Casuarina forest species are found in all states and territories. Examples include: Australian Capital Territory:

Casuarina cunninghamiana (river she-oak). New South Wales:

C. cristata (belah), C. cunninghamiana, C. glauca (swamp oak), C. pauper, Allocasuarina leuhmanii (buloke), A. verticillata (drooping she-oak), A. littoralis (black oak).

Northern Territory: A. decaisneana, C. equisetifolia (coast she-oak).

Queensland: A. leuhmannii, C. cristata, C. equisetifolia, A. torulosa (forest oak), A. littoralis, C. cunninghamiana, C. glauca, G. australianum (Daintree pine).

South Australia: A. verticillata, C. pauper, A. decaisneana, A. luehmannii.

Tasmania: A. verticillata, A. littoralis.

Victoria: C. pauper and/or A. luehmannii, A. verticillata.

Western Australia: C. cristata, A. huegeliana, A. decaisneana, C. obesa, A. fraseriana (Western Australian she-oak).

Values and uses

Wood

The wood of some casuarina species is used in flooring, cabinetmaking and other ornamental woodworking. The Western Australian she-oak (Allocasuarina fraseriana), for example, is used for making furniture and forest oak (A. torulosa) is used to make roof shingles. The quantity of wood available for such purposes is small because the resource is limited and the products are expensive and keenly sought after.

Coast she-oak is used for timber, poles, pulpwood and mulch and is also reputed to be an excellent fuelwood because it is relatively smokeless when it burns. It also produces high-quality charcoal. Belah is often used for fence posts and firewood.

Environmental

Casuarina forests are important for biodiversity, supporting a wide range of vertebrate and invertebrate fauna. The glossy black cockatoo (Calyptorhynchus lathami), which is endangered in parts of its range, depends on seeds of the forest oak and black oak (A. littoralis) as its primary food source.

In many agricultural areas, drainage and flood mitigation measures undertaken mostly during the period 1960–1990 caused a decline in casuarina forests along creeklines and watercourses.

Casuarina vegetation communities associated with swamps and rocky outcrops have been relatively protected from interference and many occur within conservation areas. Even these, however, are threatened by increased waterlogging and salinity as a result of clearing and the fragmentation of upland forests.

Coastal development and urbanisation are also affecting casuarinas in wetlands and in the zone just above high tide.

Casuarinas such as belah are often used in reforestation because of their value as windbreaks and in soil reclamation and erosion control. They are also planted in many other countries for these purposes – including in the United States (especially California and Hawaii), China, Egypt, India and New Zealand.

Indigenous uses

Indigenous people traditionally use the hard wood of she-oaks for making boomerangs, shields and clubs. In Wyrie Swamp, South Australia, archaeologists found a 10 000-year-old boomerang made of she-oak wood. Young shoots are chewed to reduce thirst, and cones are also eaten.

Other uses

The foliage of some species, such as river she-oak and belah, is used as fodder for stock during drought. Casuarina bark has been used in tannin production.

Atmospheric nitrogen fixation

Casuarina roots fix atmospheric nitrogen through nodules that contain specially adapted symbiotic actinomycete bacteria of the genus Frankia. Because of this, casuarinas can grow on nutrientpoor soils and in other marginal environments, such as granite outcrops or sandy soils.

References and further reading

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Melbourne.

Doran J and Turnbull J (eds) (1997). Australian Trees and Shrubs: Species for Land Rehabilitation and Farm Planting in the Tropics, ACIAR Monograph No 24, Australian Centre for International Agricultural Research, Canberra.

Gurumurthi K, Nicodemus A and Siddappa (eds) (2001). Casuarina Improvement and Utilization, Institute of Forest Genetics and Tree Breeding, Coimbatore, India.

Marcar N and Crawford D (1995). Trees for Saltland: A Guide to Selecting Native Species for Australia, CSIRO Press, Melbourne.

Midgley S, Turnbull J and Johnston R (eds) (1983). Casuarina Ecology, Management and Utilization, CSIRO, Melbourne.

MIG (Montreal Process Implementation Group for Australia) (2008). Australia’s State of the Forests Report 2008, Bureau of Rural Sciences, Canberra.

NFI (National Forest Inventory) (2003). Australia’s State of the Forests Report 2003, Bureau of Rural Sciences, Canberra.

Wilson K and Johnson L (1989). Casuarinaceae. Flora of Australia, Volume 3, Australian Government Publishing Service, Canberra.

Website

www.daff.gov.au/forestsaustralia

Footnotes

1 Australia’s definition of forest is ‘an area dominated by trees having usually a single stem and a mature or potentially mature height exceeding 2 m and with an existing or potential crown cover of overstorey strata about equal to or greater than 20%.’

Australian forest profiles: Eucalypts

Eucalypts are iconic Australian forests. Almost all the 700 known eucalypt species are native only to Australia.

Eucalypt forests evolved from rainforest ancestors, adapting to an environment in which nutrient-poor soils were common and the land was increasingly arid. Fire has also been an important evolutionary factor; many eucalypts have evolved strategies for adapting to and recovering from fire.

Eucalypt forests are by far the continent’s most common forest type, covering more than 116 million hectares (79% of Australia’s native forest estate).

Three genera – Eucalyptus, Corymbia and Angophora – are usually referred to as eucalypts. In this profile, ‘eucalypt forests’ are those forests dominated by Eucalyptus or Corymbia.

Eucalypts belong to the Myrtaceae family, which also includes, among other genera, bottlebrushes (Callistemon species) and tea trees (Leptospermum and Melaleuca species).

Where are Australia’s eucalypt forests?

Eucalypt forests are found throughout Australia except in the most arid regions (Figure 1). For national reporting, eucalypt forests are grouped into 11 categories defined by dominant species and structure (Table 1). The most important of these are the eucalypt medium woodland (38% of Australia’s total forest area), eucalypt medium open forest (19%) and the eucalypt low woodland (9%).

The forests of southeastern Australia contain a wider range of dominant eucalypt species than those of southwestern or northern Australia. In the southeast, the greater topographic variability results in major changes in species groupings.

In southwestern and northern Australia, where the topography is less variable, a few species of eucalypts, such as woollybutt (E. miniata), stringybark (E. tetrodonta) and jarrah (E. marginata), dominate large areas of forest, although many other species occur in localised areas.

What’s in a name?

The word ‘eucalyptus’ is derived from the Greek words eu, meaning ‘well’, and kalyptos, meaning ‘covered’. This refers to the operculum (bud cap) that covers the stamens (male floral parts) during the development of the eucalypt flower and falls off as the flower blooms.

Many eucalypts produce a resinous gum, giving rise to the common name ‘gum tree’. Most species produce large numbers of small flowers grouped in clusters, which attract insects to assist in pollination, but some develop fewer, larger flowers that are pollinated by birds and sometimes mammals.

 

Figure 1: Eucalypt forest distribution

Table 1: Area of eucalypt forest types

Forest type Area (’000 hectares) % of total native forest

Eucalypt low closed 44 0.03

Eucalypt low open 2,648 1.8

Eucalypt low woodland 13,423 9

Eucalypt mallee open 376 0.3

Eucalypt mallee woodland 8,871 6

Eucalypt medium closed 254 0.2

Eucalypt medium open 28,145 19

Eucalypt medium woodland

56,187 38

Eucalypt tall closed 123 0.2

Eucalypt tall open 5,881 4

Eucalypt tall woodland 497 0.3

All eucalypt 116,449 79

Other 30,948 21

Total native forest 147,397 100

Source: MIG (2008).

Values and uses

Wood

Wood harvested in eucalypt forests is used for many purposes, including house construction, furniture manufacture, handicrafts, veneer, poles, piles, girders, fuelwood and pulp and paper. Slow-growing eucalypts, such as those in the wheatbelt and goldfields of Western Australia, produce some of the world’s densest timbers.

   

Environmental

Eucalypt forests are extremely important for the conservation of Australia’s biodiversity and the maintenance of ecosystem processes. They provide habitat for a part of the continent’s rich array of plant and animal species, help protect soil and water values in important catchments, including the Murray–Darling Basin, and constitute a reservoir of carbon.

Indigenous uses

Indigenous people use a great range of materials from eucalypt forests for traditional purposes. The seeds of many eucalypt species are ground and made into cakes, while the forests also yield foods such as fruits and nuts, berries, tubers of rushes and yams, grass seeds, honey, wallabies, possums,

snakes and lizards. The bark of mallee roots is roasted, pounded and chewed, and flowers of some eucalypts are soaked in water to make sweet drinks. The wood is used for fuel and fashioned into spears, digging sticks, clap-sticks, clubs and boomerangs. Resins are used for making adhesives, medicines, and dressings for wounds.

Eucalypt forests also provide much of the raw material for a flourishing contemporary Indigenous art and craft industry that produces carvings, bark paintings, fibre craft weavings, ochres and dyes. The industry generates hundreds of jobs and is worth millions of dollars a year to Indigenous communities.

Other uses

Many eucalypt forests provide nectar and pollen for an economically and socially important apiary industry. Eucalypt forests, particularly open forests, are widely used for camping, bushwalking and bird watching.

Eucalypt woodland forest

Eucalypt woodland forest makes up nearly half (70.1 million hectares) of Australia’s total native forest estate. It occurs in four main areas: tropical northern Australia; subtropical and warmtemperate eastern Australia; the warm temperate southwest; and the cool temperate regions of southeastern Australia, including Tasmania (Figure 2).

More than one-third (42%) of all eucalypt woodland forests (excluding mallees) occur in Queensland and there are also large areas in the Northern Territory (29%) and Western Australia (16%). Tropical eucalypt woodland forests range in height from very low to very tall and often feature an understorey of palms, cycads and grasses. The majority of eucalypt species is evergreen, meaning that they retain their leaves year-round. Some species in the seasonally inundated cracking clays of northern Australia, however, lose all or part of their leaf canopies when waterstressed and flower and have a flush of growth just prior to the start of the monsoonal rains. This characteristic is called ‘drought deciduousness’.

In temperate regions, the natural distribution of eucalypt woodland forests largely coincides with the country’s agricultural heartlands. As a consequence, most such woodlands are now remnant patches in agricultural and pastoral landscapes.

River red gum (E. camaldulensis) is the most widely distributed of the eucalypt species and is found in all Australian mainland states. Some of its most extensive forests occur as woodlands along the Murray River and its tributaries.

   

Figure 2: Eucalypt woodland forest distribution

 

Figure 3: Eucalypt woodland forest tenure, by state and territory, 2008

Ownership and management

Most eucalypt woodland forests are on leasehold or private land (Figure 3), but nearly 9% are in nature conservation reserves and 3% are in multiple-use public forests. Forty-five per cent of Western Australia’s eucalypt woodland forests occur on ‘other crown land’, which is crown land

reserved for purposes such as scientific research, education, stock routes, mining and use by the defence forces or Indigenous communities.

   

Eucalypt open forests

Figure 4 shows the distribution of eucalypt open forests in Australia. In the southeast, these forests can be quite diverse, containing up to 10 eucalypt species per hectare. Others, such as the southwest’s open jarrah forests, are dominated by only one or two species. The largest expanses of eucalypt open forest are in New South Wales (44% of the total), Queensland (18%), the Northern Territory (17%) and Victoria (12%). In general, open forests occur where average annual rainfall exceeds 600 millimetres and where the phosphate level of the soil is moderate by Australian standards. Tall open forests (with trees at least 30 metres tall) are found in southwestern Australia and, on the east coast, in a discontinuous arc of high-rainfall country ranging from northeastern Queensland to southern Tasmania, where the dominant species changes gradually with latitude.

   

Ownership and management

One-third of eucalypt open forests (12.2 million hectares) is owned privately, 29% (10.8 million hectares) is on leasehold land, and just over 18% (6.69 million hectares) is in nature conservation reserves (Figure 5).

Historically, jarrah (E. marginata) and karri (E. diversicolor) forests in Western Australia’s southwest have provided much of the state’s timber supply. In recent years the sustainable sawlog yield has declined as more of these forests have been placed in nature conservation reserves (and consequently are no longer available for harvesting) and as forest harvesting practices have been modified.

One of the most commercially important forest species in coastal New South Wales and Queensland is blackbutt (E. pilularis).

Australia’s tall trees

Tall open forests – also known as wet sclerophyll forests – are open forests dominated by trees at least 30 metres tall. This forest type contains large quantities of plant biomass per unit area, and also includes trees that are among the tallest in the world.

Mountain ash, Eucalyptus regnans, is the world’s tallest flowering plant, reaching heights of more than 100 metres. Mountain ash forests occur in Victoria’s Central Highlands (east of Melbourne), the Otway Ranges, and the Strzelecki Ranges in Gippsland. Other tall-growing ash species include alpine ash (E. delegatensis), silvertop ash (E. sieberi), and messmate stringybark (E. obliqua), which occur in the wetter mountains of Victoria and Tasmania. The ash group of eucalypts is particularly important for the supply of timber for house frames, flooring, furniture and, because of their light colour, much of the native forest pulp production for papermaking in southeastern Australia. Ash forests are also critical for the conservation of biodiversity and watershed protection.

Figure 4: Eucalypt open forest distribution

Figure 5: Tenure of eucalypt open forest, by state and territory, 2008

Research on alternatives to clearfelling in Australia’s eucalypt forests

Recent research has led to the development of new silvicultural regimes designed to replace most clearfelling and improve forest conservation. As a result of research undertaken at the Warra Long-term Ecological Research Site in Tasmania, for example, variable retention silviculture has been applied operationally in several locations in the state.

 

Eucalypt closed forest

Eucalypt closed forest usually occurs in wet or sheltered areas at the margins of, or within, open eucalypt forest. Victoria contains more than half the 420 587 hectares of eucalypt closed forest

mapped in Australia, the Northern Territory almost 20%, Western Australia 13%, Queensland 10% and New South Wales just over 2% (Figure 6). There are no significant eucalypt closed forests reported in the Australian Capital Territory, South Australia or Tasmania.

Ownership and management

Nearly half (44%) of all eucalypt closed forest is in multipleuse public forests, mainly in Victoria, about 21% is in nature conservation reserves, and 19% is on private land.

Figure 6: Eucalypt closed forest distribution

 

Figure 7: Trends in the area of jarrah andkarri available for timber harvesting, 1970 to 2005

Reductions in sustainable yield in Western Australia

Since 1970, the area of native forest available for timber production in the state’s southwest has decreased by about 50% (Figure 7). This reflects a shift in state government policies.

Recently sustainable yields were reviewed during the preparation of the Forest Management Plan 2004–13, which covers all the main timber production areas in the state’s southwest. As a result of this review, the sustainable yield for sawlogs was reduced because of large increases in conservation reserves (and therefore decreases in the area of forest available for harvesting) and more conservative forest management practices. Sustainable yields for jarrah and karri sawlogs were lowered by 63% and 64%, respectively, over pre-2004 levels (Figures 8 and 9).

Figure 9: Karri (Eucalyptus diversicolor) sawlogtimber harvested relative to agreed limits

Note: 2003–4 limits represent a transition from previous limits tocurrent limits established under the Forest Management Plan 2004–13.

Figure 8: Jarrah (Eucalyptus marginata) sawlogtimber harvested relative to agreed limits

Note: 2003–04 limits represent a transition from previous limits to current limits established under the Forest Management Plan 2004–13.

 

Eucalypt mallee forest

Mallee eucalypts have multiple stems arising at ground level from a large woody structure known as a lignotuber or mallee root. There are up to 250 eucalypt species of mallee form. Most are found in southwestern Australia, where as many as threequarters of the eucalypt species are mallees (Figure 10). Not all mallee is forest; trees must be taller than 2 metres at maturity and crown cover greater than 20%.

Most eucalypt mallee forests occur in areas where average annual rainfall is in the range 250–400 millimetres and most rain occurs in winter. Where rainfall is higher, mallees are replaced by woodlands of single-stemmed eucalypts, sometimes of the same species. Where rainfall is lower, mallee forests usually give way to acacia forests or to shrublands and grasslands.

Ownership and management

Most mallee forests are found in South Australia (68%), New South Wales (23%), Victoria (16%) and Western Australia (13%). There are no mallee forests in the Australian Capital Territory, the Northern Territory or Tasmania. A substantial proportion (51%) of mallee forest is within nature conservation reserves, the majority in Victoria and South Australia (Figure 11).

Almost all mallee forest outside nature conservation reserves is used for cattle grazing. There is little active management for wood production because productivity is low.

 

 

Further reading

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Melbourne.

Brooker M and Kleinig D (2002). Field Guide to Eucalypts: Volume 2: South-western and Southern Australia, Revised edition, CSIRO Publishing, Melbourne.

Brooker M and Kleinig D (2004). Field Guide to Eucalypts: Volume 3: South-eastern Australia, 2nd edition, CSIRO Publishing, Melbourne.

Brooker M and Kleinig D (2006). Field Guide to Eucalypts: Volume 1: South-eastern Australia, 3rd edition, CSIRO Publishing, Melbourne.

Eldridge K, Davidson J, Harwood C and van Wyk G (1994). Eucalypt Domestication and Breeding, Clarendon Press, Oxford.

Hillis W and Brown A (1984). Eucalypts for Wood Production, 2nd edition, CSIRO Publishing, Melbourne.

MIG (Montreal Process Implementation Group for Australia (2008). Australia’s State of the Forests Report, Bureau of Rural Sciences, Canberra.

Slee A, Brooker M, Duffy S and West J (2006). EUCLID: Eucalypts of Australia, 3rd edition, Centre for Plant Biodiversity Research, Canberra.

Turnbull J (2003). Eucalypts in Asia. Proceedings of an International Conference held in Zhanjiang, Guangdong, People’s Republic of China, 7–11 April 2003, ACIAR Proceedings No 111.

Australian forest profiles: Mangroves

Mangroves are important and widespread coastal ecosystems in the intertidal zone of tropical, subtropical and protected temperate coastal rivers, estuaries and bays. Individual species have characteristic tidal-zone or preferred upriver estuarine locations. Australia has around 980 000 hectares of mangrove forests, which is less than 1% of Australia’s total forest cover.1

Australian mangrove forests comprise 41 species from 19 families of plants, which vary with degree of tidal inundation and latitude. More than half the world’s mangrove species occur naturally in Australia.

Mangroves live in a constantly changing environment. Typically they are inundated by seawater at high tide, exposed at low tide, and might receive flushes of fresh water, especially during periods of high rainfall. Apart from rapidly altering salinity levels, such influxes of fresh water are often accompanied by significant changes in water temperature.

Mangrove species have specialised dispersal mechanisms. The seeds of many germinate on the tree and remain attached through early development, before falling into the ocean to be washed to distant shorelines, where they may lodge and grow.

White mangrove (Avicennia marina) is Australia’s most widespread and common mangrove tree species. Several other salt-tolerant species grow in mangrove forests, such as the mangrove palm (Nypa fruticans), which occurs in tropical mangrove forests, and the mangrove fern (Acrostichum speciosum), which inhabits the mangrove forest floor. In tropical areas, ferns and orchids often grow on the trunks and branches of mangrove trees.

The structure and height of mangrove forests vary with the environment. Mangrove trees are usually between two and 10 metres in height, but in high rainfall areas of far north Queensland they can grow to 30 metres. Mangroves can form dense, almost impenetrable stands of closed forests, often dominated by only one or two species, as well as less dense stands characterised as open forests and, to a lesser extent, woodlands. Closed mangrove forests, which comprise about 56% of the total mangrove forest estate, provide coastal protection from storm and wave action. Mangrove trees can live for up to 100 years.

A forest assessment revised the area of mangroves upwards from 749 000 hectares in 2003 to 980 000 in 2008 (Table 1). This is largely explained by an improvement in forest measurement technology, particularly the increasing availability of highresolution remotely sensed data.

Source: National Forest Inventory, 2008Note: The resolution of forests shown on this map has been enhanced to ensure their distribution is

visible at the national scale.

Dealing with salt

Mangrove species are adapted to tidal inundation and high salinity in coastal estuaries, inlets and bays. They deal with salinity in three ways: by excluding the dissolved salt as their roots absorb water; by absorbing the salt and then exuding it through special glands in their leaves; and by concentrating the salt in bark or older leaves, which carry it with them when they are shed. Some mangroves use only one of these methods, others two or more. A number of features serve to prevent water loss from mangrove plants. These include a thick waxy surface layer, and dense hairs on the leaf to reduce the loss of water through transpiration.

 

Source: Environmental Protection Agency, Queensland.

Table 1: Area of mangrove forest, 2003 and 2008 (’000 hectares)

2003 2008 Difference Difference %

Mangrove forest 749 980 +231 +31

Source: NFI (2003), MIG (2008).

Where are Australia’s mangrove forests?

Mangrove forests are widespread in tropical, subtropical and some temperate regions of the world. In Australia, most mangrove forests are located across the tropical north. But there are also isolated stands of one species, the white mangrove, in Victoria, South Australia and temperate Western Australia (Figure 1). The southernmost occurrence of mangroves in Australia is at Wilson’s Promontory, Victoria.

In tropical regions, mangrove forests are more diverse and widespread than those in the temperate zone, with the greatest concentration of species along the northeastern coast of Queensland. The number of species decreases further south as a result of lower winter temperatures, and from east to west across the tropics with decreasing rainfall. Some experts consider mangroves to be a special form of tropical rainforest because the two forest types have many families of plants in common. In Australia, however, mangroves are usually considered to be a separate forest type.

Mangrove roots

All plant roots need oxygen to survive. The soft sediments in which mangroves grow, however, are frequently low in oxygen. To cope with this, most mangroves have developed aerial roots (pneumatophores) that rise above the surface of the mud. These take in oxygen, which is then transported to the deeper roots, where water and nutrients are absorbed. The shapes of the aerial roots vary enormously, but the three most conspicuous types are pencil roots (found in Avicennia species), knee roots (found in Bruguiera species) and stilt roots (found in Rhizophora species). The true root systems of mangrove trees are shallow, extending less than two metres below the mud surface, but they spread horizontally in a dense mass over large distances. Many mangrove species have a greater proportion of plant material below the surface than above, a feature that helps them to remain anchored in the soft mud and sand.

source: Environmental Protection Agency, Queensland

 

Ownership and management

Queensland has the largest area of mangrove forest (44%), while the Northern Territory (37%) and Western Australia (17%) have most of the remainder. More than 34% of the total area is on private land, including Indigenous land (Table 2).

Mangrove management today falls under a wide range of legal jurisdictions. It has been estimated that approximately 18% of Australia’s mangrove forest communities are protected in national parks and other forms of reserves (MIG 2008). In Queensland, all mangroves are completely protected under the Fisheries Act 1994.

Values and uses

Wood

Historically, many mangrove forests have provided useful products such as tannin, poles, firewood, charcoal and, occasionally, milled timber. Australian mangrove forests, however, are no longer harvested commercially for timber.

Environmental

Mangroves play important roles in the ecology of wetlands and estuaries. By reducing the speed of currents and trapping sediments, mangroves protect the shoreline from erosion and help to reduce silt accumulation in adjacent marine habitats. In addition, river-borne nutrients and chemicals are trapped and recycled within these communities. Mangroves are highly valued for their unique biodiversity. They provide habitat and breeding sites for a wide variety of birds, fish, amphibians, insects, small mammals and other aquatic fauna. Several rare species are found in mangrove ecosystems, such as the rusty monitor (Varanus semiremex), which utilises the hollows of mature or dead mangrove trees in northeastern Queensland.

The lesser noddy (Anous tenuirostris melanops), a sea bird that builds a platform nest out of leaves in mangrove trees, is listed as vulnerable under Australia’s Environment Protection and Biodiversity

Conservation Act 1999.

Table 2: Tenure of mangrove forest, by state and territory, 2008 (’000 hectares)

Tenure NSW NT Qld SA Vic. WA Australia

Leasehold land 0 56 74 0 0 13 143

Multiple-use public forests 0 0 0 0 0 0 1

Nature conservation reserves 2 5 57 3 2 35 104

Other Crown land 0 5 89 1 0 114 210

Private land 1 248 83 0 0 2 335

Unresolved tenure 2 44 132 10 0 0 188

Total 5 359 436 14 2 164 980

Note: Totals may not tally due to rounding. The six forest tenure categories above are defined in MIG (2008, pp xvii–xviii).Source: MIG (2008).

Indigenous uses

Mangroves are an important resource for Indigenous people, particularly in the Northern Territory, providing honey, fruit and medicines. Mangrove worms, found within decaying mangrove wood, are collected for food. The timber is used for implements, firewood and construction. Indigenous Australians harvest many edible fish and shellfish from mangrove ecosystems.

Shell middens

Shell middens are places hundreds to thousands of years old where the debris from shellfish and other food has been discarded by Indigenous people over very long periods. Middens in mangroves contain shellfish remains, the bones of fish, birds and land and sea mammals, charcoal from campfires, and tools made from stone, shell and bone.

Other uses

One of the key beneficiaries of mangroves is the fishing industry. Mangrove forests constitute breeding nurseries for a high proportion of Australia’s commercial and recreational fish catch, including barramundi (Lates calcarifer) and banana prawn (Penaeus merguinensis). An estimated 75% of the fish and prawns caught for commercial and recreational purposes in Queensland spend at least part of their lifecycles in mangroves.

Mangroves also provide protection for both the natural and built environments from waves and storm surges.

Some species have leaves that are palatable for livestock when other food is unavailable.

Mangrove forests provide a focus for tourism in some coastal communities. Boardwalks in particular are popular with tourists and provide an opportunity for educating people about the ecological and economic importance of mangroves.

Mangrove forests in a changing environment

Mangrove forests are naturally dynamic environments, subject to periodic fluctuations in climate and ever responsive to changes in sea level. Because of the longevity of individual mangrove trees they can provide a record of the effects of past changes in environmental conditions and of human influence in their structure and composition.

Mangrove communities interact closely with other tidal vegetation, such as saltmarsh. There is evidence that these two ecosystem types cycle from one to the other depending on the amount of freshwater flushing that occurs, which in turn depends on changes in rainfall over nearby land.

The future of mangrove forests in Australia is uncertain. While they demonstrate extraordinary adaptations to the estuarine environment, it is expected that changes such as sea level rise and increased storm severity as a result of climate change will challenge their existence in some areas. They also face increasing pressure from coastal urbanisation.

References and further reading

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Australia.

Duke N (2006). Australia’s Mangroves: The Authoritative Guide to Australia’s Mangrove Plants, University of Queensland, Brisbane.

FAO (2007). The World’s Mangroves, FAO Forestry Paper 153, Food and Agriculture Organization of the United Nations, Rome, Italy.

Lovelock C (1999). Field Guide to the Mangroves of Queensland, Australian Institute of Marine Sciences, Townsville.

MIG (Montreal Process Implementation Group for Australia) (2008). Australia’s State of the Forests Report 2008, Bureau of Rural Sciences, Canberra.

NFI (National Forest Inventory) (2003). Australia’s State of the Forests Report 2003, Bureau of Rural Sciences, Canberra.

Northern Territory Government (2002). Mangrove Management in the Northern Territory, Department of Infrastructure, Planning and Natural Resources, Darwin.

Websites

www.aims.gov.auwww.daff.gov.au/forestsaustraliawww.epa.qld.gov.au/nature_conservation/habitats/wetlands/wetlands_habitats/mangroves

Footnote

1 Australia’s definition of forest is ‘an area dominated by trees having usually a single stem and a mature or potentially mature height exceeding 2 m and with an existing or potential crown cover of overstorey strata about equal to or greater than 20%.’

Australian forest profiles: Melaleuca

There are hundreds of species in the genus Melaleuca and many other species in closely related genera, such as Callistemon. Classification of these species is being reviewed. When that review is completed, Melaleuca will likely contain 260 species or more, of which more than 220 are endemic to Australia. The remainder occur in New Caledonia, India, Indonesia, Malaysia, New Guinea and the Pacific Islands. Only a small number of these species develop the required community structure and height to be classified as forests.1

Although melaleuca forest makes up only 5% of Australia’s forest area, it is the third most extensive forest type after eucalypts and acacia. There are more than 7.5 million hectares in Australia, almost all being woodland and open forests (Table 1).

The word ‘melaleuca’ comes from the Greek melas (meaning black) and leucon (meaning white) and, when first coined, was probably a reference to the fact that some species have white bark over an inner layer of black bark, although it might also have referred to trees with white trunks and bases burnt black by fire, or to the black trunks and white branches of some Asian species. Another commonly used name for melaleuca is tea tree, although this is also applied to the closely related genus Leptospermum. It stems from the observation that shed leaves and bark can turn stream water the colour of tea. Some melaleucas are known as paperbarks because of their distinctive light, flaky bark.

Melaleuca forests occur mainly as large tracts of low woodland forest across estuarine plains and seasonal swamps in the coastal and near-coastal areas of monsoonal northern Australia. They also occur as narrow strips of dense, pure stands beside streams and in and around swamps, although these ecologically important forests are often too small to be mapped at the national level.

Where are Australia’s melaleuca forests?

About 75% of Australia’s melaleuca forest occurs in Queensland, particularly on Cape York Peninsula (Table 2 and Figure 1). A further 22% is found in the northern part of the Northern Territory. Small pockets occur along the subtropical and temperate coasts of Queensland, New South Wales and Victoria, and on the fringes of rivers and coastal wetlands, including in brackish and saline areas.

Extensive stands of swamp dominated by melaleucas, blackwood (Acacia melanoxylon) and Leptospermum species occur on poorly drained sites in northwestern Tasmania.

The dominant species in melaleuca forests vary markedly. Northern Australian melaleuca forests are dominated by broadleaved paperbark (Melaleuca viridiflora), weeping or long-leaved paperbark (M. leucadendra), silver paperbark (M. argentea), blue paperbark (M. dealbata) and yellow-barked paperbark (M. nervosa).

In southern and eastern Australia, melaleuca forests are confined to permanently wet watercourses and swamps. The most common coastal species is the paperbarked tea tree (M. quinquenervia). In Western Australia, melaleuca forests are restricted to small pockets on specific sites, such as Preiss’s paperbark (M. preissiana) in near-coastal swampy areas and freshwater or swamp paperbark (M. rhaphiophylla) along watercourses.

Source: National Forest Inventory, 2008.Note: The resolution of forests shown on this map has been enhanced to ensure their distribution is

visible at the national scale.

Table 1: Area of melaleuca forest, by crown cover, 2003 and 2008 (’000 hectares)

WoodlandOpe

nClose

d

Unknown crown cover

Total

Melaleuca 2003

1056 763 15 5 222 7 056

Melaleuca 2008

6 654 878 26 0 7 556

Note: Crown cover is the area of ground covered by tree

canopies, ignoring overlaps and gaps within individual canopies. It is usually measured from above using aerial photographs or other remote sensing imagery. In Australia, woodland has a crown cover of 20–50%, open forest a crown cover of 50–80%, and closed forest a crown cover of greater than 80%.Source: NFI (2003), MIG (2008).

Ownership and management

Nationally, 72% of melaleuca forest occurs on leasehold land and 16% on private land (Table 2). In both cases, the main land use is grazing for cattle production. Only 8% of melaleuca forest is within nature conservation reserves, while about 2% is located in multiple-use public forest or on other Crown land. 

Table 2: Tenure of rainforest, by state and territory, 2008 (’000 hectares)

Tenure NSW NT Qld Tas. Vic. WA Australia

Leasehold land 8 28 281 0 0 0 318

Multiple-use forests 82 0 184 171 9 0 446

Nature conservation reserves 309 0 881 387 9 2 1588

Other crown land 5 6 115 13 0 3 143

Private land 88 264 383 22 0 0 757

Unresolved tenure 1 4 24 0 0 0 29

Total 495 302 1867 593 18 5 3280

Note: Totals may not tally due to rounding. The six forest tenure categories above are defined in MIG (2008, pp xvii–xviii). Source: MIG (2008).

Values and uses

Wood

Melaleuca wood contains a high proportion of silica, which makes it durable in both soil and water and highly resistant to termites. It also makes the wood difficult to mill and dry, so it is not widely used commercially. Logs of straighter trees are sometimes used locally for marine piling and in boat building.

Environmental

Even small areas of melaleuca forests can provide important habitat for a wide range of species. Swamp paperbark (Melaleuca ericifolia) in the Damper Creek Reserve in Monash, Victoria, for example, contains a diversity of habitats and is considered to be a site of regional zoological significance. Melaleuca forests provide habitat for the vulnerable southern bell frog (Litoria raniformis) and an assortment of other fauna.

Drainage and flood mitigation measures, taken mostly during the 1970s and 1980s, as well as increased waterlogging and salinity, particularly in irrigation areas, have affected melaleuca forests along creek lines and watercourses in many agricultural areas. Peat and other materials have been extracted from swamps for use in horticulture, further damaging such forests. Melalueca forests have also been cleared, including for sugarcane on the Herbert River floodplain in northern Queensland.

Indigenous uses

Indigenous people in parts of the Northern Territory traditionally use the bark of long-leaved paperbark for many purposes, including for sheaths to hold stone knives and spearheads, as tinder for starting fires, to cover baking food, as a component of fish traps, as a material for blankets or capes, and to make canoes. The flowers can be sucked for nectar or soaked in water to make a sweet drink.

Other uses

Plantations of some melaleucas, particularly Melaleuca alternifolia, supply the raw material for the tea tree oil industry. Tea tree oil is an effective antiseptic and is used in creams for cuts and abrasions, shampoos, soaps, mouthwashes and toothpastes. Paperbark is used in the horticultural industry as a lining for hanging baskets. Melaleuca flowers are important for apiarists as a food source for bees and are sometimes known as ‘honey myrtles’ for this reason.

Crocodile egg industry

Saltwater crocodile (Crocodylus porosus) eggs are often taken from melaleuca wetlands. The harvesting of saltwater crocodile eggs in the wild, largely by Indigenous Land and Sea Ranger groups on Indigenous lands, has been taking place in the Northern Territory since 1984, when the controlled international trade of the species and of products derived from it was legalised.

Harvested eggs are hatched in farms. The crocodiles are grown to the desired market size and then used for skin and meat production.

 

 

Tea tree oil industry

The indigenous Bundjalung people of eastern Australia use tea trees in traditional medicine. They inhale the oil from crushed leaves to treat coughs and colds. Leaves are sprinkled on wounds and also soaked in water to make an infusion for treating sore throats and skin ailments.

The commercial tea tree oil industry came into being after the medicinal properties of the oil were demonstrated in the 1920s. When applied topically, the anti-microbial activity of tea tree oil was rated 11 times more active than phenol. The oil was produced from foliage collected from natural stands of Melaleuca alternifolia. The plant material was hand-cut and often distilled in the forest in makeshift, mobile, wood-fired bush stills. Production declined after World War II but was revived in the 1970s as part of the general resurgence of interest in natural and organic products. Many small operators collected foliage from both the wild and a large number of small plantations to meet demand.

In the 1970s and 1980s some 6 000 hectares of Melaleuca alternifolia plantations were established and mechanisation enabled the large-scale production of a consistent essential oil product. The ingredient active in most of the antimicrobial actions of tea tree oil is terpinen- 4-ol, which is now defined by an international standard.

A wide range of tea tree oil-based medical and cosmetic products is now available.

References and further reading

Baskorowati L (2006). Controlled Pollination Methods for Melaleuca alternifolia (Maiden & Betche) Cheel. ACIAR Technical Report No. 63, Australian Centre for International Agricultural Research, Canberra.

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Melbourne.

Doran J, Baker G, Williams E and Southwell I (2002). Improving Australian Tea Tree, Report for the Rural Industries Research and Development Corporation, Canberra.

MIG (Montreal Process Implementation Group for Australia) (2008). Australia’s State of the Forests Report 2008, Bureau of Rural Sciences, Canberra.

NFI (National Forest Inventory) (2003). Australia’s State of the Forests Report 2003, Bureau of Rural Sciences, Canberra.

Australian forest profiles: Plantations

In many ways, plantation forests are not much different to most agricultural crops, although they take longer to mature. They are sometimes established solely to provide environmental benefits, such as salinity or erosion control. In this profile, however, ‘plantation forest’ refers to plantations established mainly to produce a commercial product, wood.

Plantation forests are composed of softwood or hardwood tree species. Softwood species are cone-bearing trees with needle-like foliage (conifers); they mostly produce relatively soft, light-coloured wood. Hardwoods are angiosperms; they have flowers and broad leaves and their wood is generally dense, hard, strong and richly coloured.

Most softwood plantations in Australia consist of exotic (non-native) species, especially radiata pine (Pinus radiata). The one native softwood species used in plantation forestry, hoop pine, is described later in this profile. Most hardwood plantations in Australia are made up of native eucalypts.

Why grow plantations?

Plantations provide an economically viable and environmentally sustainable log resource that can be used to make timber products. They can also rehabilitate land, improve water quality and meet other environmental and economic objectives.

Australian plantations produce about two-thirds of the nation’s log supply. They dominate the economically important forestry and forest products industries, which generate about $19 billion per year in turnover and employ an estimated 120 000 people. On average, each Australian uses about one cubic metre of timber products per year, much of it derived from plantations.

The history of plantations in Australia

Australia’s first plantations were established in the 1870s, prompted by the need for timber to support settlement in regions that had little useful local supply. The early mining industry also used substantial amounts of timber and left large areas of land denuded and in need of reforestation.

Many exotic and native species were tested to identify those best suited to the climate and available sites. Radiata pine was first planted for forestry in 1876 at Bundaleer, South Australia, and in 1880 at Macedon, Victoria. By 1900, it was evident that this species was suitable for plantation forestry in many parts of southern Australia. Over time, other conifers were tested for their suitability in other regions, including the tropics and subtropics, and successful species were planted on a larger scale from the 1920s onwards.

Eucalypts were also tried; small areas of eucalypt plantation dating from the late 19th and early 20th centuries still exist today. The establishment of large areas of eucalypt plantations, however, didn’t start until the 1990s.

In 1997, the Australian, state and territory governments and the plantation timber-growing and processing industry formed a strategic partnership called Plantations for Australia: The 2020 Vision. The aim of the partnership is to increase the plantation estate to 3 million hectares by 2020. In the ten years to 2007, the plantation area increased by about 50% at an average annual rate of nearly 77 000 hectares, due mainly to private investment.

Area

Today, forest plantations cover about 1.90 million hectares, which is just more than 1% of Australia’s total forest estate and a relatively small area compared to other crops like wheat and barley (Table 1). About 1.0 million hectares (53% of the total plantation estate) is softwoods and 883 000 hectares (46%) is hardwoods.

Victoria and Western Australia each has around 21% of the nation’s total plantation forest estate. New South Wales has 19%, followed by Tasmania with 14% and Queensland with 13% (Table 2 and Figure 1).

 

Table 1: Australia’s major crops by area

Crop Area (million hectares)

Wheat 12.3

Horticulture 5.7

Barley 4.2

Timber plantations 1.90

Canola 1.24

Lupins 0.93

Oats 0.92

Sorghum 0.75

Notes: Agricultural crop areas are the five-year averages shown in Australian Crop Report 2007 (Australian Bureau of Agricultural and Resource Economics). The horticulture area comes from Bureau of Rural Sciences land use data and includes fruit and nut trees, vineyards, vegetables and flowers. The timber plantation area is for 2007.

 

Table 2: Total area of plantation forest by state and territory (hectares)

Plantations ACT NSW NT Qld SA Tas Vic WA Australia

Hardwood (mostly eucalypts) 0 70 616 23 689 49 446 54 974 199 068 190 986 294 714 883 494

Softwood (mostly pines) 9 500 285 702 2 239 188 751 122 871 75 005 219 426 106 662 1 010 155

Total* 9 500 359 139 25 928 240 305 178 301 274 173 411 876 403 681 1 902 903

* Includes mixed hardwood and softwoods and plantations for which species were not reported.

Figure 1: Plantation forest distribution

Figure 2: Tenure of plantation forest by state and territory*

Source: National Plantation Inventory data.

Plantation ownership

Until the 1990s, state governments owned most plantations in Australia, but the ownership mix is changing. Governments have sold large areas of plantations and, in addition, most new plantations are now established by the private sector. In 1999, the proportions of public and private plantations were equal at 46% (the balance being owned jointly). By 2007, however, governments owned 36% and 60% were owned privately (Figure 2).

Plantation species

Softwood species are widely used in plantation forestry because they grow well on a broad range of sites and the wood they produce is suitable for many purposes. The dominant plantation softwood species in temperate regions is radiata pine, although maritime pine (P. pinaster) is also planted widely in southern Western Australia. The main exotic softwoods planted in tropical and sub-tropical regions are Caribbean pine (P. caribaea) and slash pine (P. elliottii) and hybrids of those species.

The only native conifer planted for wood production in Australia is hoop pine (Araucaria cunninghamii). It occurs naturally in rainforests and, in plantations, performs best on deep loam soils. First planted in 1916, the total hoop pine plantation estate covered 45 684 hectares in 2005, of which 95% was in southeast Queensland, 3% was in northern Queensland and 2% was in northern New South Wales.

Due to the rapid expansion of hardwood plantations, the proportion of softwoods in the total plantation estate declined from more than 80% in 1995 to 53% in 2007.

More than 90% of the hardwood plantation estate is composed of Eucalyptus species, particularly Tasmanian blue gum (Eucalyptus globulus), which makes up almost two-thirds of the total. Other commonly planted eucalypts are shining gum (E. nitens), blackbutt (E. pilularis), flooded or rose gum (E. grandis), mountain ash (E. regnans), Gympie messmate (E. cloeziana) and Dunns white gum (E. dunnii). Other hardwood species used in Australian plantations include Corymbia species (which are closely related to Eucalyptus), acacias, African mahogany and teak.

Table 3 shows the main plantation species grown in various climatic regions and their uses.

How are plantations managed?

Forest plantation management has many similarities to the management of agricultural crops. The species is chosen depending on the desired end-use and site suitability, the site is prepared

using mostly mechanical means, and the crop is established and tended to ensure efficient production. Pesticides are used to reduce weed growth when the trees are small and fertilisers are sometimes applied to boost growth. The pesticides used by plantation forestry in Australia were all first developed for use in agriculture. The process of establishing, growing and harvesting a single crop of trees is called a rotation.

Table 3: Main plantation species used, by climatic region

Region Main species Main products

Hardwoods

Tropical – high rainfall

Mangium

Paper productsSub-tropical – medium rainfall

Flooded gum, Dunns white gum, Gympie messmate

Temperate – medium-to-high rainfall

Blue gum, shining gum

Tropical – high rainfall

African mahogany, teak, some native species

Sawn timber for furniture, flooring and other high-value uses

Several regions Various eucalypts Sawn timber for building and furniture

Softwoods

Temperate – medium rainfall

Radiata pine

Sawn timber for building, joinery, furniture, plywood, other high-value uses, posts and poles. Residues are used for paper, particleboard and other panels

Tropical, sub-tropical – medium rainfall

Caribbean pine, slash pine and hybrids

Temperate – low-to-medium rainfall

Maritime pine

Tropical, sub-tropical – high rainfall

Hoop pine

In Australia, softwood plantations are managed primarily to produce sawlogs, usually on rotations of 30 years or more (50 years for hoop pine). At specified times, thinning operations remove the smallest and most poorly-formed trees, leaving the best-performed ‘sawlog’ trees to grow to the end of the rotation. These trees may also be pruned to remove lower branches, helping to improve sawlog quality. Harvested sawlogs are processed in sawmills and their products used in the 150 000– 170 000 houses built in Australia each year, as well as to make furniture, toys and other items. In 2007, nearly 4 million cubic metres of sawn timber were made from sawlogs harvested from Australian softwood plantations. The products of thinnings are used as fence posts and poles and, along with the residues of sawmilling, to make fibreboard, particleboard and paper products.

Most hardwood plantations are managed to produce pulpwood for paper. Pulpwood from some eucalypts – including Tasmanian blue gum – is especially suitable for printing and writing papers, whereas softwood pulp is generally used to make packaging and other lower-quality papers. Eucalypt and acacia pulpwood plantations can be grown in rotations as short as 10 years.

A small proportion of Australia’s hardwood plantations are managed on rotations of 20 years or more to produce sawlogs for furniture, flooring and other products where appearance is important. Interest in growing hardwood sawlogs in plantations is increasing as supplies dwindle from native forests.

As well as producing fibre for paper, logs from short-rotation eucalypt plantations can also be used to make structural timber products. Technology has been developed to saw young eucalypt logs to make timber suitable for studs, bearers, joists and trusses in residential, commercial and industrial building. Small eucalypt logs can also be shredded and recombined to make ‘engineered strand lumber’ that has applications in industrial flooring, engineering, formwork and exceptionally long-span girders.

 

Environmental aspects

Many studies have found that timber has a lower environmental impact than alternative materials such as steel, aluminium, concrete and plastic. Table 4 shows, for example, that the materials used in a typical wood-framed house act as a net store of carbon, while the materials used in a steel-framed house cause net emissions of greenhouse gases.

Figure 3: Number of bird species observed duringsurveys in three habitats in northeast and central-west Victoria

Table 4: Comparison of material use and effect on carbon emissions and storage to build a typical 180 m2 house

Wood-framed house Steel-framed house

Frame only 13 m3 wood 5 tonne steel

Total house 21 m3 wood 8 m3 wood

Total carbon stored (tonnes) 9.7 3.7

Total carbon released to the atmosphere (tonnes) 2.2 6.6

Balance of carbon (tonnes stored (+) or released (-) to the atmosphere) +7.5 -2.9

Source: Turner (1990).

Forest plantations provide habitat for flora and fauna species that might be absent on cleared agricultural land. Surveys in northeast and central-west Victoria, for example, found that eucalypt plantations supported higher densities of forest birds than nearby cleared farmland, and slightly lower densities than native forest (Figure 3).

Native animals frequently observed in exotic softwood plantations include echidnas, kangaroos, wombats, possums, birds (such as the yellow-tailed black-cockatoo) and a wide range of insects. Generally, however, the level of biodiversity in such plantations is less than in eucalypt plantations.

Codes of Practice or other regulatory requirements apply to plantations across Australia to protect environmental and other values. These codes and regulations prescribe operational practices such as stream buffer areas that can’t be planted, how to build and maintain roads, use of chemical fertilisers and pesticides and fire protection requirements. In addition, plantation owners may voluntarily apply for certification under schemes that require assessment of environmental management practices by independent organisations. Over half of Australia’s plantations have been certified.

Properly sited in the landscape, plantations provide other environmental benefits; they can act as windbreaks, increase water quality, reduce erosion and help control salinity.

Other uses

Plantation forests are widely used for recreational activities such as walking, cycling, riding and camping. Plantations are also being established to supply non-wood products, especially essential oils. In Western Australia, for example, mallee eucalypt plantations produce eucalyptus oil for use in pharmaceutical and cleaning products, and sandalwood (Santalum spicatum) plantations produce sandalwood oil, which is highly valued for its aromatic properties. In New South Wales, tea-tree oil, an antiseptic, is extracted from plantations of Melaleuca alternifolia. Other products produced in small quantities in plantations include resins, bush foods, fodder, cut flowers and foliage, and medicines.

An expanding plantation industry also has the potential to supply biomass for electricity and ethanol production. Some plantation timber residues are already used in place of coal for electricity generation and a number of new projects to make fuel pellets or generate energy from plantation biomass are being developed.

Other benefits and impacts

Plantations provide other benefits as well as timber products, for example, providing employment and contributing financially to the economy (Table 5). They also have impacts that are sometimes contentious, especially in rural communities where other agricultural land uses are considered more traditional. There are divergent perspectives on aspects such as social and economic values, impacts on water use, salinity and soils, use of chemicals and fire risk. A summary of these and other aspects is provided in Australia’s Plantations 2006 (Parsons et al. 2006).

Table 5: Socio-economic contribution of plantations

Plantation region Employment1 Economic value2

South east Queensland 3 452 $571 million

Green Triangle, South Australia and Victoria 8 765 $778 million

Central Tablelands, New South Wales 1 947 $525 million

Murray Valley, New South Wales and Victoria 5 885 $837 million

Central Gippsland, Victoria 2 997 $512 million

Notes:1 Direct and indirect employment in plantation timber growing, harvesting and processing.2 The measures of economic value used in regional studies differ so that it is not practical to compare these figures directly. Source: Compiled from regional study reports published from 2000 to 2005 (refer Parsons et al. 2006).

Competition for water has become a major issue in many water supply catchments around Australia. Annual crops and pasture use less water than perennial vegetation, including trees, primarily because of their shorter growing seasons and shallower root systems. The canopies of native and plantation forests intercept more rainfall than pastures and other crops; this adds to their higher water use. Reforestation of pasture with timber plantations can therefore lead to reduced run-off and streamflow.

Because plantations generally occupy only a few percent of the catchments in which they are located, their impacts on water availability are usually limited. The main land uses are agriculture

and native forests (Table 6).

Table 6: Land use in catchment areas with above 600mm average annual rainfall

Land use Plantations5 Agriculture %

Native forest %

Other uses %

Catchment Proportion of catchment %

Proportion of all Australian plantations %

Millicent Coast 13.6 8.8 72.2 11.1 3.1

Glenelg, Portland, Hopkins

7.2 9.2 74.9 17.0 0.8

Lachlan, Macquarie–Bogan

1.5 3.6 73.9 21.7 3.0

Murrumbidgee 4.0 6.2 53.8 40.0 2.2

Upper Murray 2.5 2.2 27.1 68.1 2.5

Northern Victoria1 2.2 2.9 43.1 52.9 1.8

Tamar, Esk 4.1 2.2 29.9 63.9 2.1

North-west Tasmania2 9.6 4.4 35.0 54.1 1.2

Western Australia3 5.7 16.3 35.0 58.1 0.3

South east Queensland 4 2.5 9.6 47.5 48.2 1.8

Notes:1 Northern Victoria is the Goulburn, Broken, Ovens and Kiewa River catchments.2 North-west Tasmania data are for the Smithton–Burnie Coast, Mersey, Rubicon and Forth River Catchments.3 Western Australia data include all catchments in south west Western Australia from Perth to Albany.4 South east Queensland data are for the Brisbane, Burnett, Noosa, Maroochy and Mary River catchments.5 Based on plantation areas as at 2005.

 

References and further reading

Australian Bureau of Agricultural and Resource Economics 2008. Australian Forest and Wood Products Statistics, September and December quarters 2007.

Bureau of Rural Sciences and Forest and Wood Products Research and Development Corporation 2005. Socioeconomic Impacts of Plantation Forestry. Bureau of Rural Sciences, Canberra.

Davidson, J. 2008. Wood is Good: The Climate Change Mitigation and Environmental Credentials of Australia’s Wood and Wood Products, Bureau of Rural Sciences, Canberra (in press).

Davidson, J., Davey, S., Singh, S., Parsons, M., Stokes, B. and Gerrand, A. 2008. The Changing Face of Australia’s Forests. Bureau of Rural Sciences, Canberra.

Gavran, M. and Parsons, M. 2008. National Plantation Inventory 2008 Update, National Forest Inventory, Bureau of Rural Sciences, Canberra.

Jenkin, B. and Tomkins, B 2006. Chemical use in plantations and agriculture. Forest and Wood Products Research and Development Corporation, Melbourne.

Loyn, R. H., McNabb, E. G., Macak, P. and Noble, P. 2006. Eucalypt Plantations as Habitat for Wildlife. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Heidelberg, Victoria.

Montreal Process Implementation Group for Australia (2008). Australia’s State of the Forests Report 2008. Bureau of Rural Sciences, Canberra.

Parsons, M., Frakes, I. and Gerrand, A. 2007. Plantations and Water Use. Science for Decision Makers series, Bureau of Rural Sciences, Canberra.

Parsons, M., Gavran, M. and Davidson, J. 2006. Australia’s Plantations 2006. Bureau of Rural Sciences, Canberra.

Turner J. 1990. Forestry, the Timber Industry and the Greenhouse Effect. Forestry Commission of NSW Miscellaneous Paper. Forestry Commission of New South Wales, Sydney.

Australian forest profiles: Rainforest

Australia’s rainforests comprise only about 2% of the country’s total forest area but make a disproportionately large contribution to its biodiversity.

‘Rainforest’ is a general term for a range of broad-leaved forest communities with closed canopies. Rainforest canopy species are shade-tolerant trees that are able to establish in the understorey and take advantage of canopy gaps that might open up as a result of tree falls, lightning strikes or other disturbances. Unlike many Australian forest species, rainforest canopy trees do not depend on fire for their regeneration.

 

Part of the appeal of rainforests is their strong contrast with the arid and semi-arid communities that dominate most of the Australian continent. Conservation campaigns and tourism advertising have contributed to their popularity by promoting lush, iconic images of them. The high biological diversity, structural complexity and aesthetic appeal of tropical rainforests in particular, together with the presence of unique animals such as the cassowary (Casuarius casuarius), have also contributed to the high level of interest in rainforests and the priority given to their conservation.

There are many types of rainforest in Australia, varying mainly with rainfall and latitude. Tropical and subtropical rainforests occur in northern and eastern Australia in wet coastal areas as far south as New South Wales. Dry rainforests are a variation of tropical and subtropical rainforests; they occur in pockets protected from frequent fire in sub-coastal and inland areas across northern and eastern Australia. Monsoon rainforests occur in northern Australia in the seasonally dry coastal and sub-coastal regions. Some of the tree species in these rainforests are semideciduous, often losing their leaves at the end of the dry season.

Temperate rainforests occur in eastern and southeastern Australia. Warm temperate rainforests grow in New South Wales and Victoria and cool temperate rainforests in Victoria and Tasmania, with a few outliers at high altitude in New South Wales and Queensland.

Rainforests are remnants of some of the oldest types of vegetation in Australia. Many existing plant species have ancestors that date back more than 65 million years. For this reason, rainforests have major historical and scientific significance. Australian tropical rainforests contain eight of the 14 primitive flowering plant families, while the cool temperate rainforests of Tasmania contain several primitive flowering plants and conifers, such as Huon pine (Lagarostrobus franklinii) and celery top pine (Phyllocladus asplenifolius).

Because of the small amount of light that filters through their dense tree canopies, many rainforests have only sparse vegetation at ground level, but mosses, vines and other aerial plants are common on tree trunks. Some rainforests, particularly those in the wet tropics of northern Queensland, grow vines in abundance and form the continent’s most diverse vegetation communities. Temperate rainforests and high-altitude tropical rainforests often feature ferns and mosses.

Tropical rainforest, Nightcap National Park, northeastern New South Wales.

Source: National Forest Inventory, 2008. Note: The resolution of forests shown on this map has been enhanced to ensure their distribution is visible at the national scale.

Where are Australia’s rainforests?

Rainforests account for most (77%) of Australia’s closed crown cover forest. They extend across the top of northern Australia from the Kimberley to Cape York and down the east coast to the cool temperate zone in Tasmania (Figure 1). Rainforests occur in all states and territories except South Australia and the Australian Capital Territory (Table 1). Queensland has the largest area (57% of all rainforests), followed by Tasmania (18%), New South Wales (15%) and the Northern Territory (9%).

Rainforest in a sheltered, moist gully, where it receives protection from frequent fire.

In all but the areas of highest rainfall, rainforest occurs in discontinuous patches in locally sheltered, moist areas that are protected from frequent fire. It occurs in relatively large tracts in Queensland’s wet tropics, where average annual rainfall is above 3 600 millimetres, and in western Tasmania, where average annual rainfall is higher than 3 500 millimetres. Rainforest generally does not develop where average annual rainfall is less than 1 000 millimetres.

Since European settlement, large areas of Australia’s rainforest have been cleared for agriculture. In parts of Queensland and northern New South Wales, rainforest has displaced tall, open eucalypt forests, probably because of a reduction in fire frequency.

A forest assessment in 20081 revised the area of rainforest in Queensland downwards from 2.9 million hectares (reported in 2003) to 1.9 million hectares, and the area in the Northern Territory upwards from 224 000 hectares to 302 000 hectares. This is largely explained by an improvement in forest measurement technology, particularly the increasing availability of high-resolution remotely sensed data, and improvements in forest typing methods. Estimates of the rainforest area in other jurisdictions were unchanged between 2003 and 2008.

Table 1: Tenure of rainforest, by state and territory, 2008 (’000 hectares)

Tenure NSW NT Qld Tas. Vic. WA Australia

Leasehold land 8 28 281 0 0 0 318

Multiple-use forests 82 0 184 171 9 0 446

Nature conservation reserves 309 0 881 387 9 2 1588

Other crown land 5 6 115 13 0 3 143

Private land 88 264 383 22 0 0 757

Unresolved tenure 1 4 24 0 0 0 29

Total 495 302 1867 593 18 5 3280

Note: Totals may not tally due to rounding. The six forest tenure categories above are defined in MIG (2008, pp xvii-xviii).Source: MIG (2008).

Ownership and management

About 48% of Australia’s rainforests are in formally gazetted nature conservation reserves, an increase from 44% in 2003; 23% are on private land, and 14% are in multiple-use public forests and on other Crown land.

Values and uses

Wood

Rainforest timbers are prized for their fine aesthetic qualities. Although large areas of rainforest are now protected, small-scale, selective harvesting still occurs on private land in some states. In

Tasmania, some rainforests provide a small ongoing supply of timber for high-value uses such as joinery and woodcraft.

Environmental

Australian rainforests cover a relatively small area of the continent (about 0.4%) but are disproportionately important for the conservation of biodiversity. They contain 60% of the country’s unique plant families and about 17% of all Australian bird species. Far north Queensland’s wet tropical rainforests contain about 30% of Australia’s marsupial and frog species and 62% of its butterfly species. Five of the 13 ‘hotspots’ of plant diversity identified in Australia are dominated by rainforest and a further three have rainforest components.

About 1.04 million hectares of rainforest (32%) is in Australia’s World Heritage conservation areas; 654 000 hectares (63%) of this is in Queensland, and there are also significant areas in the Tasmanian Wilderness World Heritage Area.

Indigenous uses

Rainforests have a high density of tree-dwelling fauna, such as possums and birds, and have traditionally been used as hunting grounds. Freshwater creeks in tropical rainforests are home to many traditional food sources, including yabbies, fish and turtles.

Other uses

Tourism is now the main economic use of rainforests, particularly in far north Queensland and Tasmania. Bioprospecting surveys continue to seek species useful for medical and dietary purposes. The production of honey from the Tasmanian rainforest species leatherwood (Eucryphia lucida) is another important use.

References and further reading

Boland D, Brooker M, Chippendale G, Hall N, Hyland B, Johnston R, Kleinig D, McDonald M and Turner J (2006). Forest Trees of Australia, 5th edition, CSIRO Publishing, Australia.

Floyd A (1989). Rainforest Trees of Mainland South-eastern Australia, Inkata Press, Melbourne and Sydney.

Francis W and Chippendale G (1970). Australian Rainforest Trees, 3rd edition, Australian Government Publishing Service, Canberra.

MIG (Montreal Process Implementation Group for Australia) (2008). Australia’s State of the Forests Report 2008, Bureau of Rural Sciences, Canberra.

Webb L and Kikkawa J (eds) (1990). Australian Tropical Rainforests: Science, Values, Meaning, CSIRO Publishing, Melbourne.