AUSTRALIA'S BEST KEPT SECRET: the wonder of our woodlands.
LIKE GATECRASHERS at a giant biological party, squatters and settlers revelled in the natural bounty of Australia's woodland ecosystems from the first days of European colonisation. The starry-eyed visions of future settlement and prosperity related by early explorers-and historians stand in contrast to the present-day stories of the same regions, which are all too often laden with warnings of extinction, salinity and rural decline.
What was it that lured the colonists so compellingly? Perhaps it was the same qualities that draw to these areas today an increasing number of botanists, bird-watchers and biologists, who are helping us to understand the ecological stories of these pastoral and agricultural districts.
Picture yourself ...
Woodlands span the gap between forests and grasslands. In a true `forest' the close canopy of trees captures much of the light and warmth of the sun and, together with the generally thicker under-brush, creates the dense structure and bulk of vegetation that make forests grand and `fat' ecosystems.
At the opposite end of the ecological spectrum are naturally treeless native grasslands and herbfields, where the sun and wind bless the ground-level plants and wildflowers.
Striking a happy medium are the woodlands.
With between 10 and 30-per-cent tree canopy, you can sit in the shade to eat your sandwiches but still get a tan checking out the wildflowers in the glades between the trees. You can see the wildlife unobscured in the middle-distance, and wander around at night spotlighting owls without banging into too many things.
You barely need binoculars to see the birds and gliders, as the trees grow to a convenient height, and if you don't like hiking up hills, relax! Gentle undulations are about as steep as it gets in the flat, fertile country where most of Australia's woodlands are found. No wonder the settlers got excited.
Where are we exactly?
There are no straight lines in nature, and there are few absolute definitions in ecology. In reality, forests merge into woodlands, just as open woodlands may mingle with grassy plains or thick acacia scrub.
To define Australia's woodland regions, ecologists are trying to get a handle on how natural patterns of climate, topography, soil, vegetation and land use interact. Those natural patterns are complex, and just as marshes, gorges and snowplains are interspersed in the forested regions of the coastal ranges, the woodland `biome', as described at the continental scale, also contains many other landscapes and vegetation types.
Woodland regions with heavy clay soils may support fields of mitchell grass, kangaroo grass or other treeless vegetation types. Those with sandy soils may foster diverse heathlands or mallee scrubs. Rocky uplands or river valleys may also house true forests, or even vine thickets, while claypans, wetlands and other landscape features add to the diversity of the regions that are dominated by woodland communities.
The most important ecological division within Australia's woodlands relates to climate. The tropical-- temperate woodland divide is reflected in the different natural processes and different human land-uses of Australia's northern and southern regions.
Land of sheep and honey -- the southern temperate woodland
`We traversed it over two directions meeting with no obstruction except the softness of the soil, and in returning over flowing plains and green hills fanned by the breezes of early spring, I named this region Australia Felix - the pleasant land'. Major Thomas Mitchell
`Temperate woodlands' are not always temperate, though it seems that in 1836, when Major Mitchell originally surveyed the cropping and grazing country of New South Wales and Victoria, the weather was especially balmy. The clement weather came with a lush growth of grasses -- just what the explorer had hoped to find. Within a few decades, there were ten million sheep chomping their way through the woodlands and grasslands of south-eastern Australia.
Temperate woodlands once covered around 80 million hectares of southern Australia. This includes such iconic landscapes as the ironbark woodlands of Victoria, Queensland and New South Wales (from which Banjo Paterson's `Man from Ironbark' sprang), the open grassy plains that are lightly treed with various box eucalypts, and the red gum woodlands of the inland rivers. Various communities of callitris pine, she-oak and bull-oak also fall under the temperate woodland umbrella.
In Western Australia, the woodland communities of salmon gum, york gum, gimlet and wandoo -- home to numbats and red-tailed phascogales -- were seen as indicators of fertile soils, and have now been extensively cleared. And in Tasmania, the dry forests and woodlands of the midlands cropping and grazing country, once habitat for the Tasmanian tiger, are still shrinking under the expansion of plantation forestry.
What are now farmlands and townships dotted with occasional patches of remnant bush, were once whole landscapes dominated by screaming flocks of parrots and honeyeaters, gorging themselves on nectar. While most colonists had eyes only for pasture, timber and gold, George Bennett made this observation of the woodlands of the new colony in 1860:
`In New South Wales there is a very numerous family of Honey-eaters ... (elegant and gaily coloured birds), and Parakeets of brilliant plumage and rapid flight ... their crops are found filled with honey from the flowers of the Eucalyptus or gum-tree, on which they feed ... They may be observed fluttering and darting among the trees and shrubs when in blossom ... glancing in the sun, uttering their cheerful, loud, shrill, but liquid notes, gaily frolicking and fluttering incessantly about the flowers ...'
John van Voorst, Gatherings of a Naturalist in Australia, London 1860
The flocks have shrunk and disappeared from many areas, but you can still witness the mad mayhem of rioting honeyeaters, lorikeets, parrots and friarbirds when the rich woodland eucalypts are in bloom.
Nectar, pollen, wattle-gum and other carbohydrates are key resources for woodland wildlife. Some bird species migrate from as far away as Papua New Guinea, enticed by the flowering yellow box and other eucalypts. Several mammals also depend on these rich food sources, including sugar gliders, squirrel gliders, and to a lesser extent tuans, which leaven their diet of spiders and cockroaches with nectar.
In spring though, the ground-level wildflowers leave the trees for dead. Lilies and orchids, peas and native bluebells, wattles and everlastings, in an infinite range of colours, attract their own migration of naturalists and wildflower tourists.
Strolling through a honey-scented dell carpeted with chocolate lilies and orchids, one is at a loss to understand how we have permitted so much of our temperate woodlands to be destroyed. One wonders, too, why we continue to allow what is left of these woods to be treated so poorly.
Today, about 90 per cent of Australia's temperate woodlands have been eliminated. Some communities, particularly grassy woodlands, have fared worse still, for example only 0.01 per cent of grassy white-box woodlands in New South Wales and Victoria survive.
The culprit has been land clearing (permanent conversion of natural ecosystems to agricultural or urban land uses), along with inappropriate management and use of most remnant woodlands. This loss and degradation has caused an array of severe, long-term environmental problems, including large and growing areas of dryland salinity (the greatest threat to flora and fauna in some regions) and major losses in biodiversity, best exemplified by a wave of extinctions in woodland birds.
Domestic stock are grazing away the diversity of the ground-flora, at the same time suppressing the recruitment of tree and shrub seedlings. Meanwhile, cutting of firewood, posts and railway sleepers, in volumes that rival the woodchip industry, is simplifying the woodland structure and leading to denser stands of younger trees.
As a result, today's southern woodlands have few tree hollows for owls, gliders and other wildlife to nest in. The young trees are also unable to produce nectar in such profusion as older ones, pushing many nectar-dependent wildlife to the brink. On top of this, the wildlife now have to compete for food and habitat with domestic and feral bees, other pests and weeds, the mining industry and urban development.
Of all Australia's wooded habitats, temperate woodlands are the most depleted and suffer from the greatest range of severe threats. Yet their level of protection in conservation reserves is shockingly low. While as much as one third of some tall, wet forest types are protected, as they should be, in national parks and reserves, less than two per cent of most temperate woodlands are similarly protected.
With so much gone and so much to lose, every patch of bush counts. In some districts most remnant bush is on public lands allocated to timber production or other resource extraction, where creation of major new reserves should be a priority. In other areas, remnants scattered on private and leasehold land are all that is left. Here, incentives for farmers to manage their remnant bush appropriately, controlling stock or establishing voluntary conservation covenants are the way ahead.
Woodland species at steak -- the tropical zone
`So bleak is the picture ... that the bulldozer and not the atomic bomb may turn out to be the most destructive invention of the 20th century'.
Phillip Shabecoff on the destruction of wildlife habitat, New York Times Magazine, 4 June 1978
Bulldozers linked by massive chains and followed by plumes of diesel smoke and salt are now racing northward into Queensland's tropical woodlands. This clearing, mostly for beef farming but also for cropping and urban development, is repeating the mistakes made in the woodland regions further south where huge areas of temperate and subtropical lands have been plundered. But while there have been many media stories about this over recent years, little has been said about what exactly is being lost.
Northern Australia's tropical eucalypt woodlands (also known as tropical savannas) cover the great bulk of the country from central and northern Queensland, across the Top End to the Kimberley and south to the drier acacia (wattle) woodlands of the semi-arid zone of Central Australia. In the far north these tropical woodlands are dependent on the monsoonal summer rains, which lead to a dense growth of grasses that dry out in the winter.
These grasses hold the key to the ecology of tropical savannas. Pigeons, finches and other seed-eating birds flock in their thousands throughout northern Australia, feeding on the abundant grass seed in the great swathes of savanna woodland and grassland. Tourists flock here too, of course, to see savanna landscapes evocative of Africa's Serengeti plains, abounding with wallarroos, emus and other wildlife.
The abundant seeds and grasses are also relished by many unique mammals such as the spectacled hare-wallaby and the delicate mouse. Other species, like the golden-backed tree-rat and black-footed tree-rat, extend their diets to the trees' fruits, flowers and nectar. Then there are the many woodland-dwelling reptiles such as the frilled lizard and the northern bandy-bandy, which, along with the great majority of our woodland animals, are found nowhere else on earth. In fact, the abundance, variety, colour and curiosity of life in the northern savanna woodlands is one of Australia's greatest natural wonders.
So amid all this life, and with relatively little clearing of monsoonal tropical woodlands as yet, why we are witnessing a serious decline in the region's bird species? Populations of gouldian finches and many other savanna birds are gradually disappearing. The beautiful golden-shouldered parrot is facing extinction. The paradise parrot is already extinct, and was in fatal decline at the turn of the twentieth century, well before the widespread clearing of its habitat began in southern Queensland.
These birds are declining because, just as temperate woodland birds are suffering from the loss of the nectar-rich eucalypts, so these savanna birds are missing out on their meals of grass seeds. The introduction of stock, along with changes to the timing and frequency of fires, has caused complex changes in savanna ecology and reduced the availability of seed. Tree-rats and other mammals are also known to have suffered marked contractions in range since European settlement, for reasons which are not yet clear, but may also be linked to grazing and changed fire regimes.
Continued research and cooperative management planning between ecologists, pastoralists and Aboriginal people is vital, so that the right timing, frequency and intensity of grazing and burning can be achieved in the northern savannas.
That is assuming that the bulldozers do not get there first. While only small areas of the far northern tropical woodlands have been cleared so far, they are increasingly at risk from clearing proposals for irrigated horticulture, pastoral development and cropping. Meanwhile, the gross clearing and resultant extinctions and salinity problems which occurred in southern temperate woodlands are now far advanced in sub-tropical New South Wales, and extend well into Queensland's tropical woodlands.
Every minute of every day, an area of native bush, mostly woodlands, the size of between one and two football fields, is destroyed in Queensland (see February 2000 Habitat). Poplar box, gidgee, brigalow, melaleuca and other woodland ecosystems are fast disappearing, taking with them mahogany gliders, squatter pigeons, bilby snakes, regent honeyeaters and many other dependent species.
Woodlands for our future
`Although we talk of species, the patterns described are of entire ecosystems disappearing. The scale of change is not of individuals or of populations, but of functional units of interacting organisms. Once destroyed, it is no more likely that an ecosystem can be restored to its original state ... than an extinct species can be resurrected from its bones'. Recher and Lim 1990
Before European arrival, woodland ecosystems covered nearly 40 per cent of Australia, or more than three million square-kilometres. These woodlands, almost five times the size of Australia's original forest ecosystems, formed a complex mantle across what are now Australia's cropping and grazing lands. The soil, water and ecological resources of Australia's woodlands formed the basis of a huge experiment in pastoral and agricultural development that continues today.
The richness and diversity of the woodlands attracted rapid development, particularly in temperate regions. In sub-tropical woodlands, `development' is still synonymous with land clearing, a practice that today is rapidly eating north into tropical woodland areas, which are already suffering from a complex range of ecological disturbances.
Despite their many unique species, special characteristics and the range of looming threats they face, Australia's woodlands have received far less conservation attention than better known and relatively better managed ecosystems.
It is said that we learn from our mistakes, so let there be no doubt: we will lose many of our woodland seed eaters, nectar feeders, hollow-dwelling animals, birds and reptiles if we continue destroying our woodland ecosystems. To lose the mellifluous fluting of the regent honeyeater would be tragic, and to deny future generations the bedazzling sight of flocking finches and firetails would be unforgivable.
There is also no doubt of the need to change land use and management practices in these regions if we want to stem the decline of agricultural productivity and halt the scourge of salt.
This way, once again, `travellers throughout these vast plains [may] all concur in their admiration of the luxuriance of the soil, the salubrity of the climate, and the loveliness of the entire landscape ...'.
`Travellers throughout these vast plains all concur in their admiration of the luxuriance of the soil, the coolness and salubrity of the climate, and the loveliness of the entire landscape. We could fill pages with descriptions of a countless rills rising, cool and limpid, from their vine-clad slopes -- of deep rivers stealing through waving meadows -- of the golden sunlight, the rosy atmosphere, and the songs of innumerable birds, which gave an additional charm to each scene.'
David Blair, The History of Australasia, London 1879
Woodland? What woodland?!
The Macquarie Dictionary entry for `woodland' is `land covered with woods or trees', which is about as useful as defining a human as a mammal. A more informative definition is provided by Raymond Specht et al, who, while admitting that the definition of plant communities is largely subjective, hold that a woodland is a vegetation community whose tallest element is trees (woody plants usually with a single stem) and where the foliage projective cover, or tree canopy, is between 10 and 30 per cent.
`Open' woodlands are treed areas with even less than 10 per cent canopy cover. Those areas with between 30 and 100-per-cent canopy cover are considered to be true forests. The trees in woodlands tend to be shorter than forest trees, possibly due to the generally lower or more episodic rainfall in woodland regions.
Most experts draw a further distinction, defining `tropical woodlands' or `tropical savannas' as north of the Tropic of Capricorn, while temperate woodlands are to the south. Some definitions also list as separate the sub-tropical woodlands of south-central Queensland and northern New South Wales.
Another line of differentiation is that of land use and threatening processes. While forests form the basis of the ghastly woodchip industry, firewood is the major timber product stripped from remnant woodlands. Timber cutting, as well as grazing, mining and other degrading processes, have significant and widespread impacts. But clearing is far and away the greatest threat to the sub-tropical woodlands, and an increasing problem in tropical woodlands too. Generally speaking, what chainsaws are to forests, bulldozers are to woodlands.
The ironbark ark
As dusk fell, the dead tree in Victoria's Chiltern forest came alive. If you sat quietly nearby, you could watch as two squirrel gliders gingerly emerged from its rotting trunk, ascended the tree and floated off through the dry inland air to feed on flowering ironbarks. Then the tuans would take their turn -- a mother and two kids, spiralling energetically up the bole of the tree and foraging for insects under the peeling bark, silhouetted in the moonlight.
The next year, when the tree finally fell, there was not even one other large, old, hollow tree in the surrounding hundred hectares of woods. With nowhere to go and the scarce tree hollows further afield no doubt fully occupied, the future for the animals was grim.
This situation is typical throughout the broad arc of woodlands dominated by ironbarks and box trees, which characterise much of the wheat-sheep belt of Victoria, New South Wales and parts of southern Queensland. About 90 per cent of this huge area has been cleared, and what is left has been dramatically altered by timber cutting, grazing and mining. Few tree hollows remain and this, combined with declining nectar availability, is rapidly pushing species such as barking owls, tuans, regent honeyeaters and swift parrots towards extinction. In Victoria alone, 187 species of box-ironbark plants and animals are classified as threatened or near-threatened.
While Landcare groups and land-holders are making inroads with private-land conservation, the larger remnants on public land are critical for the conservation of wide-ranging and migratory woodland species. The home range of tuans can reach across 100 hectares, and some individual owls have been recorded foraging over 2000 hectares. Large areas must be set aside to sustain viable populations of such species.
In Victoria, planning for public-land use is taking a bioregional approach, and new box-ironbark conservation reserves have been recommended in a draft report from the Environment Conservation Council. While the ECC proposals will lift woodland reserves from the existing three per cent to six per cent of the ecosystem's original extent, it falls well short of what is required to protect and re-invigorate the state's woodlands. Meanwhile, in New South Wales and Queensland there has been no systematic review of public land use in the box-ironbark country at all.
So long, and thanks for all the beef: Queensland's Brigalow Belt
The Brigalow Belt in Queensland is a fine example of how to diminish diversity: encourage clearing ... through taxation and other incentives; fail to secure in conservation reserves representatives of all vegetation types in the region; recognise late, after several species have become extinct or are in decline, that a major problem in maintaining diversity exists; and proceed with plans for further development ...
JA Covacevich, PJ Couper, KR McDonald, Memoirs of the Queensland Museum, 1998
Queensland's Brigalow Belt stretches in a 350-kilometre swathe from the New South Wales border north to Townsville, and is characterised by the Acacia harpophylla (brigalow) woodlands. Only 2.2 per cent of the area is protected in conservation reserves.
While grazing pressure, timber cutting, inappropriate fire regimes and exotic weeds (most notoriously the prickly pear) have all placed stress on the species and ecosystems of this region, the ball and chain is the major culprit. Clearing using large bulldozers harnessed together with a ship's anchor-chain weighted by a giant steel ball has been a speciality of the region since the 1960s. Clearing continues at around 2000 square kilometres per year, every year.
This has resulted in the Brigalow Belt now having the largest number of threatened ecosystems of any Queensland bioregion (70 out of a total of 163 vegetation types are considered threatened), and some of Australia's most threatened woodland species. Included in the toll is the northern hairy-nosed wombat, which has been reduced to just 70 animals. Eighteen reptile species are considered at risk, including the pretty golden-tailed gecko and Allan's lerista (a burrowing skink that may soon have the dubious distinction of being the first reptile extinction in Australia's history).
Expansion of beef farming is the main excuse for clearing. A major destroyer of vegetation, AMP, owns the biggest cattle herd in Australia and holds permits to clear more than 100,000 hectares of bush (equivalent to one fifth of Australia's total annual clearing rate) through its subsidiary, Stanbroke Pastoral Company. Most of this bush is said to be `regrowth', or previously cleared vegetation. Regrowth bush can still have high conservation values, however, and the impact of clearing 100,000 hectares on ground-water tables, regional salinity and greenhouse gas pollution may be considerable. The great irony is that AMP is also a major player in the insurance industry, which is struggling to limit the risks involved with global climate change.
What you can do
You can help to protect woodlands in your state or territory by supporting local conservation groups and letting our politicians know your views.
Federal government -- Write to the Prime Minister, Parliament House, Canberra, ACT 2600. Urge him to protect our wildlife, farmlands and future prosperity by
* listing land clearing as a Matter of National Environmental Significance under the Environment Protection and Biodiversity Conservation Act, and
* providing funds to ensure that enforceable clearing controls are introduced in all states and territories.
Queensland -- Write to the Premier of Queensland, PO Box 185, Brisbane Albert Street, 4002. Urge him to enact the Vegetation Management Act 1999 and provide funding to ensure that land clearing is prohibited in
* endangered and `of concern' ecosystems
* areas of high nature conservation value
* areas vulnerable to land degradation.
For more information contact the Queensland Conservation Council, Ph: (07) 3221 0188.
Tasmania -- Write to the Premier of Tasmania, Executive Buildings, 15 Murray Street, Hobart 7000. Ask him to enact interim native vegetation clearing controls in line with federal-state agreements.
For more information contact the Tasmanian Conservation Trust, Ph: (03) 6234 3552 or The Wilderness Society, Ph: (03) 6234 9366.
Western Australia -- Write to the Premier of Western Australia, 197 St Georges Terrace, Perth 6000. Urge him to put an end to land clearing in the rural, urban and pastoral districts of Western Australia. For more information contact the Conservation Council of Western Australia, Ph: (08) 9420 7266.
ACT -- Write to the Chief Minister of the ACT, GPO Box 1020 Canberra 2601. Ask her to guarantee protection of grassy woodlands and grasslands from urban, plantation or road development and to provide adequate funding to protect woodland and grassland species. For more information call the Conservation Council of the South-East Region and Canberra on Ph: (02) 6247 7808.
South Australia -- Write to the Premier of South Australia, GPO Box 2343, Adelaide 5001. Urge him to
* strengthen the Native Vegetation Act and the Development Act
* protect woodland remnants in a comprehensive reserve system
* create a Biodiversity Act to protect threatened communities.
For more information contact the Conservation Council of South Australia, Ph: (08) 8223 5155.
Northern Territory -- Write to the Chief Minister of the Northern Territory, PO Box 3146, Darwin NT 0801. Ask him to introduce enforceable land clearing controls across all land tenures.
For more information call the Environment Centre of the Northern Territory on Ph: (08) 8981 1984.
New South Wales -- Write to the Premier of New South Wales, Parliament House, Macquarie Street, Sydney 2000. Ask him to ensure that
* the Native Vegetation Conservation Act is properly enforced
* breaches are prosecuted,
* a comprehensive and scientific assessment of NSW western woodlands is undertaken and a comprehensive, adequate and representative woodland reserve system is established.
For more information call the Nature Conservation Council of NSW, Ph: (02) 9279 2466, or National Parks Association of NSW, Ph: (02) 9299 0000.
Victoria -- Write to the Minister for Environment and Conservation, 8 Nicholson St, East Melbourne 3002. Ask her to
* stop land clearing in Victoria
* protect remnant box-ironbark and brown stringybark woodlands in northern and south-western Victoria in a comprehensive reserve system.
For more information contact Environment Victoria, Ph: (03) 9348 9044, or Victorian National Park Association, Ph: (03) 9650 8296.
You can also help by becoming an ACF member or making a donation to help fund our woodlands campaign. Call us toll free on Ph: 1800 332 510. For more information about woodlands and land clearing, visit ACF's website: www.acfonline.org.au/campaigns.htm.
This supplement is part of Habitat magazine of the Australian Conservation Foundation. 340 Gore Street, Fitzroy, 3065 Ph: 9417 0767 Fax: 9416 0767 Website: www.acfonline.org.au Copies are available for $1.50 each by calling ACF on Ph: 9926 6732. Special prices apply to bulk purchases.
Charlie Sherwin is ACF's Biodiversity Campaign Coordinator. He can be contacted by email: firstname.lastname@example.org.
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|Date:||Aug 1, 2000|
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