Sunset at Longreach. (Credit: Steve Wilson)

Desert channels: heart of Australia

  • May 19, 2011

The desert channel country of western Queensland is a region of historical geography and great beauty.

CONSERVATION DEMANDS THAT WE assess what we value about a place - its biodiversity, its human history, its resources, its community. Each of these defines the edges of the 'place' differently.

The desert channels are the north-eastern reaches of the great arid zone that extends over 70 per cent of the Australian continent. In this context, the region is the part of the Australian arid zone where all desert rivers rise before draining away towards the great depression of Lake Eyre. From a continental perspective, the deserts of Australia are ecologically driven by fire in the west and water in the east.

The braided channels of our region create that difference. In the western shield, there are no rivers or big flood-outs. Waterholes are patchy and more ephemeral than in the east, where irregular but large and dramatic floods make for richer ecological resources. Grasses, trees, animals and people of the desert all depend on floods in the east. Plants and animals are not conscious of political borders.

And for tens of thousands of years before British settlement, the national boundaries within continental Australia were defined very differently by Aboriginal groups. Sometimes political boundaries can be cruelly inappropriate. When the Simpson Desert peoples came together to make a native title claim in the 1990s, many people met their relatives for the first time.

The Aboriginal welfare systems of Queensland and the Northern Territory were so different that families had been separated for generations: they had lost touch with each other and with the country on either side of a border that had no meaning for their traditional culture.

Beyond borders: heart of desert channel country

Pastoralists also had a view beyond borders. European settlers did not immediately take up permanent settlement; rather, they treated this region as part of the Mitchell grasslands stock-droving trail from New South Wales to the Kimberley. As the water ran out they moved the stock on, leaving the grasslands to recover behind them - water, not grass, was the limiting factor.

They moved cattle northwards into the channel country, then into the Mitchell grass downs of the Northern Territory and beyond. Each time, the stock was moved on before the pasture ran out. The decision to move on and rest the country behind was a key to their success, but it only worked because of the continental scope of the operation.

Most of the desert channels region is in Queensland, so that state's land tenure systems have shaped its land use patterns for the past century and a half. It is now mostly pastoral leasehold and freehold country. There has been little crown land historically reserved as nature reserves or national parks - this was country that could carry stock, and development in the late 19th and early 20th centuries favoured that use.

In the era when European explorers and settlers arrived with their stock, there was little interest in the conservation of desert lands for other purposes. Even by the 1930s, when Queensland had developed an active interest in national parks and had one of the first and most active National Parks Associations in Australia, the focus was on forested temperate lands, especially those that were close to Brisbane and perceived as 'threatened'. The early Queensland National Parks Association did not consider remote outback country as either threatened or in need of conservation.

Unique regions of Australia's outback

The desert channels region is distinctive for many reasons. First, there is the immense scale of the river systems. The catchments of the Georgina, Diamantina, Thomson and Barcoo rivers begin in northern Australia and extend for more than 1000km into central and south-eastern Australia. They feed floodwaters from monsoonal Australia into Lake Eyre, in effect making this playa lake operate as a gigantic continental rain gauge.

Second, the dynamics of the slow movement of floodwater into the heart of the continent, through a variety of sumps and storages, adds another layer of environmental variability beyond that due to fluctuations in local rainfall.

And last, these long channels give the country a distinctive grain - sometimes linear, sometimes reticulate - that is more developed than in other Australian deserts.

Historical geography of the Queensland outback

There is an old idea that the structure of a landscape affects not just the ecology of a region but also its historical geography. The French Annaliste historians called it la longue durée, emphasising that long-term historical structures provided an element of continuity across the various histories of a region, contrasting with the ruptures, discontinuities and nervous ripples of more recent events.

In the case of the desert channels region, these deeper structures are provided by the arid rivers that create a broad corridor along the eastern margin of the arid zone. They form a chain of ecological, cultural and historical connections across 10° of latitude, a vast swathe across the interior of the Australian landmass. We can see this structure in the geography of Aboriginal trade and exchange systems in the Lake Eyre basin.

The archaeologist John Mulvaney popularised the phrase 'the chain of connection' to describe the exchange of goods, ideas and ceremonies in Aboriginal Australia. He pointed out that the distances travelled by groups or individuals for these exchanges were greater in the Carpentaria-Lake Eyre region than in most other parts of the arid zone. At 400-480 km, these were some of the longest 'chains of connection' in arid Australia (and probably the world).  

Desert Channel partnerships

National and international organisations have recognised the unique importance of the desert channels region in the megadiverse continent of Australia. They have also recognised the crucial role for partnerships between the people on the ground, governments and private conservation organisations in achieving national and international conservation aspirations.

Conserving a community is good for biodiversity, and respecting cultural heritage does not mean losing natural diversity. Working together across the visions for conservation is essential for all of them.

This is an edited extract from Desert Channels: the impulse to conserve (CSIRO publishing).

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