The Memory of Trees: The future of eucalypts and our home among them

By Viki Cramer

Most Australians see their world through eucalypts. From towering forests to straggly woodlands, in city parks, by the coast and in the bush, these are the trees that inhabit our familiar landscapes and national psyche. Yet the resilience of our eucalypt ecosystems is being tested by logging and land clearing, disease and drought, fire and climate change. In many places they are a faded remnant of those known by past generations. How important is the memory of these trees?

In search of answers, Viki Cramer takes us on a journey through the richest botanical corner of the continent, exploring forests of rugged jarrah and majestic karri, woodlands of enduring salmon gum and burnished-bark gimlet. Spending time with the people caring for these precious places, she interrogates the decisions of the past, takes a measure of the present and glimpses hope for the landscapes of tomorrow.

The Memory of Trees will make you look anew at the trees and environments that sustain us and show the many ways that, together, we can ensure their future.

• Language: English
• Publisher: Thames & Hudson Australia Pty Ltd
• Release date: Jun 27, 2023
• ISBN: 9781760762377

Book preview

Most Australians see their world through eucalypts. From towering forests to straggly woodlands, in city parks, by the coast and in the bush, these are the trees that inhabit our familiar landscapes and national psyche. Yet the resilience of our eucalypt ecosystems is being tested by logging and land clearing, disease and drought, fire and climate change. In many places they are a faded remnant of those known by past generations. How important is the memory of these trees?

In search of answers, Viki Cramer takes us on a journey through the richest botanical corner of the continent, exploring forests of rugged jarrah and majestic karri, woodlands of enduring salmon gum and burnished-bark gimlet. Spending time with the people caring for these precious places, Cramer interrogates the decisions of the past, takes a measure of the present and glimpses hope for the landscapes of tomorrow.

The Memory of Trees will make you look anew at the trees and environments that sustain us and shows the many ways that, together, we can ensure their future.

–

Viki Cramer is a writer and ecologist who lives on Noongar Country in the south-west of Western Australia. In 2021 she was awarded a Dahl Fellowship from Eucalypt Australia.

‘This brilliant ecological history of south-west Western Australia is a testament to the area’s beauty and diversity, as well as a calling to account of the sustained failures in stewardship since white colonisation. The Memory of Trees celebrates the local while speaking to the global: the power of trees and community, and the urgent need to take responsibility for the landscapes that sustain us.’

—Inga Simpson

For Margaret and Luis, my roots and branches.

Note on the spelling of Noongar and Ngadju words

Noongar (the people of the south-west of Western Australia) are made up of fourteen dialectal groups, with each group connected to a particular geographic area and its associated ecosystems. These groups are Amangu, Yued/Yuat, Whadjuk/Wajuk, Binjareb/Pinjarup, Wardandi, Balardong/Ballardong, Nyakinyaki, Wilman, Ganeang, Bibulmun/Piblemen, Mineng, Goreng, Wudjari and Njunga. The Noongar Language Centre states that there may have been between three and fifteen Noongar dialects at the time of European colonisation. Many words are similar between the dialects but may be pronounced slightly differently. Noongar language also contains vowel and consonant sounds not found in English. This diversity and difference are reflected in many Noongar words having alternative spellings when transcribed into the Latin alphabet. For example, Noongar may also be spelt Nyungar, Nyoongar, Nyoongah, Nyungah, Nyugah or Yunga. For consistency throughout the text, I have used the spelling of Noongar words as given on the Kaartdijin Noongar – Noongar Knowledge website of the South West Aboriginal Land and Sea Council (noongarculture.org.au).

Ngadju is a language of the southern Goldfields region of Western Australia, with speakers centred around Norseman and east to Balladonia. The Goldfields Aboriginal Language Centre (wangka.com.au) states that the Ngadju language is severely endangered. Spelling of Ngadju words in the text have been taken from Ngadju Kala: Ngadju Fire Knowledge and Contemporary Fire Management in the Great Western Woodlands, published by CSIRO in 2013.

Contents

Map of south-west Western Australia

Chapter 1 The catena

Chapter 2 Surviving in one place

Chapter 3 The illimitable forest

Chapter 4 Of virgins and veterans

Chapter 5 The target and the tension

Chapter 6 Islands of yesterday

Chapter 7 The last great woodland

Chapter 8 Whatever happened to salinity?

Chapter 9 Healing land, healing people

Chapter 10 A different kind of love

Common and scientific names of plant species referred to in the text

Acknowledgements

Notes

Index

When we destroy trees, we destroy ourselves.

Jakelin Troy

Map of south-west Western Australia

CHAPTER ONE

The catena

The sun has sunk low to the horizon but the temperature remains defiant. The dog can wait no longer so we leave the house and cross the road to the park to begin our circumnavigations. The air is heavy and still, pressing hot against my cheek like the breath of an unwelcome confidante, resisting my legs as I wade through it. We meander on and off the concrete path. The dog follows his nose and I follow the canopy line of the trees, seeking out their cool shade.

I have walked among these trees for so many years now that their life stories are intertwined with my own. There’s the towering tuart, (Eucalyptus gomphocephala) blown apart by lightning on the day I fell off the ladder while trying to clear the gutter amid the downpour of a summer storm, while my then-toddler son screamed in fear and fury through the screen door. I was not injured and, though decapitated, the tuart made an astonishing recovery. We thought it was done for. There’s the slender banksia (Banksia attenuata), with open branches held at amenable angles, the first tree I lifted my son up into to climb. I fear every summer will be its last, as its scant leaves fade dull brown and brittle, but each mid-winter it regains its colour. Just beyond, there’s the small and shapely tuart by the rust-coloured rock where we stood with the wedding celebrant as our friends semicircled us, champagne or beer in hand. The flower buds of a tuart are shaped like an ice-cream cone bearing a single, perfectly domed scoop. There was once a grand old grass tree here too, tall and skirted with a heavy petticoat of dead leaves. Its crown has since toppled and been carted away by the local council. On the low corner near our house is a grove of marri (Corymbia calophylla), bloodwoods with tessellated bark. They always make me think of witches, with the distinctive curve of their gnarled branches held out from their trunk like the raised arms and arthritic hands and fingers of a crone conjuring over a crystal ball. They stand in a coven of animated conversation, the ground beneath them knobbly with a carpet of their fallen fruit, so chunky in size they are known locally as ‘honky nuts’.This summer the marri flowered with such abundance that their pale blossoms outshone the lights of any Christmas tree. Later, flocks of Carnaby’s black cockatoos will descend to chomp and crunch the marri fruits before daintily plucking out the seeds with their searching tongues. I swear I have seen them grasp the topped nuts in their claws and lift them like a chalice to their beaks, drinking down a stream of seeds.

There are a few hulking dark pines in the corner near the car park and, on the corner opposite, an eclectic arboretum of eucalypts from other places planted in a long-armed right-angle. Some I can easily identify from books and websites. The red ironbark (Eucalyptus sideroxylon) and yellow gum (Eucalyptus leucoxylon) from south-eastern Australia are common street trees in my neighbourhood. When they flower, their canopies become a foliage diamanté, studded with coral-pink blossoms. There’s a warted yate (Eucalyptus megacornuta) from the far south of Western Australia, its long flower buds reminiscent of a cockatoo’s rough tongue and its flowers of a yellow anemone. There are trees I feel are river red gums (Eucalyptus camaldulensis), familiar to me from the banks of the slow-flowing rivers of inland Queensland, and a species I once studied, but so widespread across the continent and varied that seven subspecies have been described. I collect leaves, flower buds and fruits from the ground and use an online identification key just to be sure. I snap off small branches bearing glossy olive-green leaves from a short tree with a Y-shaped trunk, and use the key to reveal long-flowered marlock (Eucalyptus macrandra).There are the ramrod trunks, mottled with smooth dusk-pink bark, of what I think to be lemon-scented gums (Corymbia citriodora), native to tropical and temperate eastern Australia. Or they could be spotted gums (Corymbia maculata). Their lower branches are too high, and so I search day after day for a sprig of fresh leaves fallen to the ground. I crush a pliant young leaf between my fingers and it releases a rush of the scent of citrus – citriodora. And then there are the other trees I pass as I do other dog-walkers: I acknowledge them with a smile, but do not know their name.

A small grove of olive trees drops fruit the colour of a deep bruise onto the concrete path. Before it became surrounded by the brick and tile of late 1960s suburbia, this square of land was once part of a smallholding, one of many carved out of a 400-hectare bullock paddock. Before that it was coastal forest, and most of the trees here – tuart, jarrah, marri, banksia, sheoak, peppermint and balga (grass tree) – are from this place. I leave the path where it curves before the line of olive trees, and walk behind a patch of bush fenced and replanted by the local council. Here, hidden away in the loneliest corner of the park, is a tuart made up of three great trunks and one lesser one, rough with grey bark. They are arranged like the toes on a foot of one of the juvenile magpies I often see lying prone in play with a sibling. I walk this way just to greet it. I have no story for this tree. I like to take a moment to appreciate its old age and quiet dignity. In the past this tree might have been revered for the power of its presence, but now people park their cars under it or drive past without turning their heads, urgent to get home. Some days my head is full of words and I only give it a passing nod. Some days I have a feeling that, if I sat with it a while, it might have a story to share with me.

I live on Whadjuk boodja – Whadjuk land – which stretches along the Swan Coastal Plain from Yanchep in the north to Derbal Nara (Cockburn Sound) in the south, east across the Darling Scarp and west into the Indian Ocean around Wadjemup (Rottnest Island). You might know this land as the Perth metropolitan region and the rolling hills of forest and farmland to its east. Whadjuk are part of the Noongar Nation, the people of the south-west of Western Australia, and one of the fourteen Noongar dialectal groups whose ‘tribal boundaries’ were mapped by anthropologist Norman Tindale in the late 1930s.¹ I have learnt that the way Noongar think about such things is far more nuanced and complex, and that I must view Tindale’s map as merely a guide rather than a cartographic fact.

I was not born on Noongar boodja but made my way here a little over twenty years ago, moving across the continent on a whim. I came here with one way of knowing, the science of ecology, which helped me see patterns in the landscape and the signs of whether the land was healthy or not. But I had no knowledge grown in this place. I found my way into this landscape through its trees. It was a slow journey. It still is. I am a poor botanist, failing to store the distinguishing traits and names of species in a way that I can easily conjure from memory. My brain, I have decided, is just not wired that way. And the south-west of Western Australia was like no place I had been. Botanically, it is the richest corner of the continent. An analysis of data held at the Western Australian Herbarium found the Southwest Australian Floristic Region (the area west of a line that runs roughly from the north of Kalbarri, 500 kilometres north of Perth, to east of Esperance on the state’s far south coast) contains 8379 plant taxa (species and subspecies).² Just one national park, Fitzgerald River National Park on the south coast east of Albany, contains more than 1750 species of flowering plant. And therein was my problem. Few plants looked familiar and there was too much of everything, especially in the Proteaceae, that spiky, hard-nutted family of plants that contains banksias, grevilleas and hakeas. I could not reliably tell my Grevillea from my Hakea, my Isopogon from my Petrophile. I was secretly relieved when taxonomists decided that everything formerly known as Dryandra was now to be lumped in with Banksia. I still couldn’t name even the most common species, but at least I had a chance of getting the ‘banksia’ bit right.

The eucalypts, though, I had a chance with them. Well, I had a chance with the most widespread species: jarrah, marri, tuart, karri, wandoo, York gum, salmon gum and gimlet, perhaps even some of the mysterious mallets. They are the trees, in the words of author Murray Bail, that compose the landscape.³ The colour and texture of their bark, the pattern of their branching, the way they held their leaves and how they glinted in the sun or absorbed the light, the shape of their flower capsules and spent gum nuts: these things I could recognise.

I borrowed John Beard’s Plant Life of Western Australia.⁴ The key to understanding the vegetation of the south-west region, more than any other, he wrote, was to understand the catena, the sequence of soils along a single slope.⁵ Beard was adamant: soil and vegetation are absolutely interrelated, and controlled by topography. The sequence repeats itself across the region, but the species found in any segment varies with rainfall. Here was a pattern I could follow and a few dominant eucalypts I could learn to identify. I studied his diagram of the relationship between soil and vegetation typical of the wheatbelt region that encompasses much of the south-west of the state. On the valley floors where soils are loams heavy with clay, I could expect to find salmon gum (Eucalyptus salmonophloia) and gimlet (Eucalyptus salubris). In late summer, both bare burnished new bark that has a lustre as if lit from within – orange-pink for salmon gum and copper-red for gimlet. Salmon gum leaves are held aloft on long branches like fabric across the spokes of an umbrella. They sparkle in the sun. When not copper-red, the deeply grooved and often twisted trunks of gimlet can be olive-green or bronze. They too bear a crown of glossy leaves.

A little upslope on loam soils, I would see wandoo (Eucalyptus wandoo) with its dull blue-green leaves, straight trunk and smooth white bark that turned a creamy yellow. But I had to be careful not to confuse it with the powderbark wandoo (Eucalyptus accedens) that often grows with it, but is distinguished by winter bark that is rougher, creamy pink to orange and decidedly powdery to the touch. Or with the similar-looking wheatbelt wandoo (Eucalyptus capillosa) that replaces wandoo in the soil sequence in the central and eastern wheatbelt. A little higher still, on the sandy loams, there would be woodlands of York gum (Eucalyptus loxophleba subsp. loxophleba), easily recognised by their wide canopies borne on multiple stems clothed in rough and flaky grey bark. But here it got a little tricky – on the western edge of the wheatbelt, where rainfall is more reliable and streams flow regularly, York gum grew on the valley floors. The sequence Beard described, though reliable, needed interpretation.

As I approached the top of the valley slope, the soils would become sandy loam over clay, known as duplex soils, and the vegetation would become mallee – eucalypts that grow as tall shrubs, hardy and many stemmed. Then, as the valley rise curved up onto the plain between valleys, the duplex soils would become sands, the most nutrient poor and water scarce of the sequence. This is where woodland and mallee give way to heath-like vegetation called ‘kwongan’ (derived from kwongkan, the Noongar word for sandplain⁶). In the western and central parts of the wheatbelt I would become most familiar with, deep sand supports taller species such as acorn banksia (Banksia prionotes), slender banksia and sandplain woody pear (Xylomelum angustifolium), while an alliance of Acacia, Allocasuarina and Melaleuca known as mixed kwongan grows on soils of moderate depth. Shallow sand over ironstone gravel supports a short scrub-heath of dense tamma (Allocasuarina campestris), where small shrubs of Acacia, Hakea, Grevillea and Melaleuca jostle for a space within the tamma thicket. Plant communities merge and mingle into each other, the pattern of vegetation following the design of the soil. Woodlands are mixed with mallee; mallee mixed with heath and studded with patches of woodland.

Growing between and among the handful of easy to identify trees and less knowable shrubs were roughly another 153 species of eucalypt, in the wheatbelt alone, for me to learn to identify. But it was a start. I already knew jarrah (Eucalyptus marginata) and marri from the Swan Coastal Plain and, in the forests further south, karri (Eucalyptus diversicolor), all towering pale bark and architectural bend to its branches, could not be mistaken for anything else. Here too the sequence: karri on the edges of creeks and swamps and on the foot slopes, merging into karri and marri, then jarrah and marri as the slope rises, the trees getting shorter as the soil becomes poorer. Then, at the top of the rise, jarrah grows small and crooked where soils are leached and poorly drained.

Once I learnt to pay it the right kind of attention, the landscape revealed itself to me through the location and form of its trees and shrubs. Since then I have learnt – and often promptly forgotten – the names of many other species, even of those elusive banksias, hakeas and grevilleas. But I still view the world around me through the lens of eucalypts.

I am not alone. Most Australians see their world through eucalypts, even if they don’t pay heed to the texture of their bark or the sheen of their leaves. Four out of five of us live within 50 kilometres of the coast, well within the domain of the forests and woodlands dominated by species of Eucalyptus, Corymbia or Angophora – the eucalypts.⁷ They are the trees people are most likely to encounter in local bush reserves or on weekend excursions beyond the city’s limits.

The coastal plains east of the Great Dividing Range in south-east Queensland, New South Wales and eastern Victoria, the eastern half of Tasmania and the south-west of Western Australia, are the domain of eucalypt open forests.⁸ Here, trees grow to between 10 and 30 metres tall and, if you look upwards, you can see the sky between their crowns. Where rainfall is more abundant, trees may grow beyond 30 metres and, in the south-east, this wetter and taller eucalypt forest may encompass patches of rainforest.⁹ The forests in the southern corners of the continent are home to the tallest flowering plants in the world: mountain ash (Eucalyptus regnans), Tasmanian blue gum (Eucalyptus globulus) and ribbon gum (Eucalyptus viminalis, also known as manna gum) in the south-east; karri in the south-west.¹⁰

Between this slim margin of forest and the vast centre of hummock and tussock grasslands and acacia woodlands and shrublands lies a transitional zone where, as rainfall drops away into the arid interior, both people and trees become increasingly sparse. Here, eucalypt forests segue into eucalypt woodlands, where the trees stand farther apart, their crowns not touching.¹¹ More sun than shade hits the ground in the middle of the day. In the dry Mediterranean climates that sweep from the south of Western Australia, across the coastline of the Great Australian Bight through South Australia and into western Victoria, eucalypts lose their tree form and become squat, multi-stemmed mallees.¹² In the tropical north, eucalypts grow straggly over a cover of tussock grasses as savanna, or spread far apart as open woodlands over grasses and shrubs.¹³

As a nation we may have a romance with the red dirt of the outback, where spinifex and mulga mingle across vast sandy plains, but, as the song goes, most of us make our home among the gum trees.¹⁴

Or perhaps it’s more correct to say we make our homes where the gum trees were.

Together, the eight major vegetation groups that are dominated by eucalypts – forests and woodlands that may be tall or low, widely spaced or less so, and mallee woodlands and shrublands that may be dense or sparse – account for over 70 per cent of all of the vegetation cleared within Australia.¹⁵ Eucalypt open forests, eucalypt woodlands and mallee woodlands and shrublands have fared the worst. About 430,000 square kilometres of eucalypt woodland and over 100,000 square kilometres each of eucalypt open forest and mallee woodland and shrubland have been cleared – a third of each vegetation group’s original extent – mostly in the intensively farmed agricultural regions of eastern and southern Australia.¹⁶ More than 13,000 square kilometres, or almost 40 per cent, of mallee open woodland and sparse mallee shrubland have been removed. If all of the land that has been stripped of its eucalypt communities was amalgamated in one place it would extend over 725,000 square kilometres – that’s 90 per cent of the land area of New South Wales.¹⁷ Imagine driving from Sydney to Hay, out to Broken Hill, up to Bourke, across to Lismore and then back down the coast through nothing more than urban sprawl, wheat stubble and desultory sheep searching for the last tufts of grass to gnaw, with not a single tree on the horizon.

In February 2000, just a month or so before I moved to Perth, conservation scientists published a map of the world’s twenty-five ‘biodiversity hotspots’ – places where ‘exceptional concentrations of endemic species are undergoing exceptional loss of habitat’.¹⁸ Only one part of Australia was marked in emergency red, a stubbed toe throbbing at the far extremity of the continent: the south-west.

When you tell a person that this flat and dry corner of the country, this place of scraggly scrub and dull-leaved trees, is home to more plant species than the rainforests of the well-watered north and east coasts of Australia – well, they scarcely believe you.¹⁹

Many of the places that have evolved a similar munificence of plant species are indeed in the tropics, where there is an abundance of water and energy from the sun, or in mountainous regions where steep slopes create a change of climate every few hundred metres.The south-west of Australia has ample sun, but most rain falls in the duller winter months.Topography varies little over hundreds of kilometres. What the south-west has had in abundance is time: tens of millions of years where no glaciers scoured the land, no new mountains were built and the climate was held steady by the proximity of the Indian Ocean to the west and south.²⁰ Tens of millions of years for rock to slowly weather away, for the mineral grains to gently shift and fan, and for plant species to evolve and diverge uninterrupted.

But then things shifted – violently – in a matter of decades. What happened to the landscapes of the south-west after Europeans arrived has been described as ‘radical disappearance’.²¹ The clearing of the forests and woodlands for agriculture was fast and loose. As the goldmining boom of the 1890s faded, jobs were scarce and export income flagged. The state government saw an opportunity for prosperity in another form of gold – wheat, the golden grain – and it aggressively pursued the expansion of agriculture.²² Farming was encouraged under an array of settlement schemes, including the group settlement of migrants from Great Britain in the early 1920s and the schemes to settle returned servicemen after both world wars.

The clearing was rapid, indiscriminate and a condition of purchase. ‘We are supposed to take everything up to nine inches out and leave the big stuff for the time being,’ reported one farmer to the 1925 royal commission into the group settlement schemes.²³ The ‘big stuff ’ was ringbarked. Each and every tree, except those needed for fence posts.²⁴

The big trees resisted their own destruction.Their roots refused to die, sending up new shoots for years. Each year, the suckers needed to be ‘bashed’ to keep the country ‘subjected’ until the trees died and could be pulled. It was often more efficient to just blow the trees up. Settlers would bore holes into the trunks and pack them with explosives, a method called ‘shooting’.²⁵

By 1949, 120 years after the establishment of the Swan River Colony in 1829, 6.48 million hectares of land had been cleared for cultivation. In the two decades that followed to 1969, the area of land cleared for farms more than doubled to 13.77 million hectares.²⁶ The big machinery developed during the Second World War meant that trees no longer needed to be ringbarked and shot. Bulldozers could push them over and heap them up for burning or, to improve efficiency, a pair of crawler tractors could drag a 2.5-metre metal ‘hi-ball’ between two 100-metre-long chains. Working this way, 200 hectares of heavy timber could be ‘disposed’ of in a forty-hour week.²⁷ By the mid-1950s, the state government’s War Service Settlement Scheme was the largest land clearance program in Australia. At the pinnacle of clearing in the early 1960s, more than 400,000 hectares (a million acres) a year were ‘alienated’ (allocated to farmers by the government) under land releases such as the New Farm Lands Scheme and the – literally named – Million Acres a Year Scheme.²⁸

The mercy seemingly granted upon the thin scrap of jarrah forest that remains between the suburban sprawl of the Swan Coastal Plain and the lightly treed paddocks at the western edge of the wheatbelt is a mirage. Most of it has been cut over – at least once, and possibly two or three times since the 1870s.²⁹ Even Charles Lane Poole, Western Australia’s famed Conservator of Forests, admitted that in the state’s ‘cultivated’ forest, trees would be cut when they reached maturity. ‘Sentiment may dictate the preservation of a few for a period far beyond that of maturity, as reminders of the giants of former days, but whole forests of giant trees will no longer be seen,’ he wrote in 1920.³⁰

Alienated: it’s an apt term for the hostility wrought as settlers tried to remake a foreign land in the image of their own.

By the 1980s, public attitudes towards trees were changing, and they were no longer viewed as, at best, a source of timber or, at worst, an obstacle to agricultural progress. In 1984, the newly elected Labor government declared a moratorium on further mass land releases and, after 1986, landholders were required to obtain a permit to clear one or more hectares of native vegetation.³¹ In 1989, Western Australia became one of the founding states of the national Landcare movement, when the Australian government committed $320 million to its ‘Decade of Landcare Plan’.³² Conservation organisations such as the Western Australia Forest Alliance drew attention to the ongoing exploitation of the northern jarrah forests, warning as early as 1991 that the ecosystem could