The Biggest Estate on Earth

by Bill Gammage

  2. Yellow and Apple Box, Canberra, September 2006

  BG. Compare pictures 16, 21–22, 34.

  Adjacent eucalypts lean different ways to dodge the shade of neighbours. You can ‘see’ those neighbours after they’re gone: smaller trees lean from the site. If the light moves, for example if a neighbour grows, trees gyrate from the shadow, if necessary reversing 180 degrees, except for balance starving branches which fall into shade and unleashing new branches to the light.

  This picture shows such gyrations. At left a Yellow Box leans away from larger trees which once stood between it and the western sun. About 1938 they were cleared to make a view, and the Box pushed into the vacant light. A stump and two branches are shown; other branches are higher up. At right an Apple Box also reached for the vacant light, but turned sharply away as its neighbour’s branches took the space. ‘Seeing’ trees not there can be invaluable.

  This land has few big trees: the nearest is about 70 metres away. Yet at rear young eucalypts and wattles, survivors of regular mowing, clutter the ground—off photo at right they are even denser. Why aren’t their grandparents as dense? Many seedlings lose the race for light and die, but under similar conditions not in one generation more than another. Some giants may have been felled by axe, fire or age, but if so more should remain as stumps or root depressions.

  They were never there. In May 1832, 7–8 years after Europeans first occupied it, Robert Hoddle surveyed this land. The Box is on a ridge he called ‘open forest’, a category between ‘grassy’ and ‘dense’ which he used elsewhere. Along the crest and upper slopes he drew a 150–200 metre wide neck of ‘open box, gum and apple’ separating ‘grassy’ plains and lower slopes, carrying few trees or none.6 The edge between them oscillates over height contours, the same soil and the same aspects, and each side of it now carries post-1788 eucalypts. That was not so in 1832 because this land was controlled by fire.

  Hoddle’s survey supports other aspects of this picture. Off-picture at left (north) the Box spreads wide: for at least most of its life no trees were there. The tussock grasses prefer open land. Most survive shade for decades, but don’t invade it. Here they are dying under the trees but thriving in open patches beyond. This too indicates that this country was once open.

  2

  3. White Gum on Ellesmere Station south of Jericho, Tasmania, 1985–6

  Fred Duncan, FPB. Compare pictures 1, 4, 6, 18, 21–4, 40, 48.

  For help I thank Fred Duncan, Greg Taylor and Charles Burbury.

  A similar photo is the front cover of Tasforests 2, Dec 1990.

  The big White Gum (Ribbon or Manna Gum on the mainland) was 200–300 years old in 1985–6.7 Its branches spread, unlike the surrounding saplings which grow straight up, racing for light. Those fast-growing youngsters caught their parent, which first lost lower branches to the shade, then bent its next branches up to compete for light. This Gum began in the open, then adapted to forest.

  Open land typified this district in 1788.8 If trees grow there now, why not then? Soil, salt, climate or aspect do not explain the change. Fire does explain it, but not bushfires. Most big eucalypts survive them, as they prove each summer. Had bushfires kept this land clear, the big Gum would show more fire damage, there would be more big gums, and we would have to explain why bushfires stopped and let the saplings grow. The fires which made this landscape were deliberate, frequent and cool, preserving the big Gum and killing generations of its seedlings.

  3

  The saplings were young in 1985–6, showing that trees can grow here, but for most of the big tree’s life did not. The land remained open for about a century after the Tasmanians were dispossessed.9 Perhaps stock kept it so until a grazing break let the saplings take hold.10 They then shaded the grass. It is White Grass. It needs open land. Its presence among trees shows that once the country was open. Now it struggles, whereas in the open beyond it flourishes.

  4. Blakely’s Red Gum on Goorooyaroo reserve near Canberra, 7 August 2005

  BG. Compare pictures 3, 6, 14–16, 18, 21–4, 40, 48.

  4

  The big Blakely’s Red Gum died aged about 200. It has no low branches, and its high branches do not spread wide, indicating that it grew with now-gone neighbours not far away. Much later the larger saplings around it got away, perhaps in a grazing break. They began to spread, then were caught by the dense stand of younger saplings, and turned their branches up, chasing the light.

  The dead Gum grew in open woodland because the land was burnt, but not by bush-fire. A bushfire would either kill the young Gum, or let it and more of its generation survive, like the youngest saplings. Killing all the saplings required fires about every 2–4 years. Kept up long enough, this would destroy all seed stock in the soil, so that except around mature or sheltered trees the country would stay open. No-one now knows how long ‘long enough’ is. For most eucalypts it is certainly centuries, but non-Aborigines have not been in Australia long enough to know how many.

  PICTURES 5–12: FIRE

  5. Eucalypt recovery from fire or drought:

  Thredbo, NSW, 17 February 2006

  BG. Compare pictures 6, 9.

  5

  These Snow Gums are regenerating from lignotubers after the hot January 2003 fire. –Mallees too re-sprout like this: near Australia’s coldest and hottest extremes eucalypts regrow similarly. In the background are gums twice this size, but really big gums are rare. Why, since the young gums are so dense?

  Snow Gum spacing varies with altitude. Near Canberra they grow in dense, tall stands at 1500 metres, are shorter, more branching and wide spaced at 1670 metres, and stunted, wide canopied and scattered at 1840 metres. In general the higher they are the tougher the conditions, the fewer they are, the more light each gets, and the more each spreads.11 But these gums, crowded young trees visible, older trees at rear, big trees absent, are at the same altitude. The change is between generations. This suggests that fire was once more common than it is now.

  Australia’s high country meadows are supposedly natural. This may be true above the present tree line (though don’t assume it), but here gums have captured meadow. How did it become meadow? Why isn’t it still, if it is natural? The obvious answer is a change from regular to sporadic fire.

  In 1840 Stewart Ryrie passed near here. He crossed the Thredbo, climbed Rams Head Range, and followed it southwest to Merritt’s Spur above Thredbo Village. ‘The highest part I reached’, he wrote,

  was covered with a short and coarse wiry grass mixed with heath, and a little lower down, long coarse grass and herbage with short scrub at places . . . The only timber growing upon them is the white gum [Snow Gum] and Messmate: the latter only at the foot of them. The white gum scrub extends two thirds of the distance to the summit and is, in most parts, dead.

  The lower part of the Mountains is covered with long, luxuriant grass.12

  Six years later surveyor Thomas Townsend saw what converted Snow Gum to grass:

  The summits of the peaks were generally more densely clad than any other part . . . The Blacks had visited the Snowy Mountains, a short time previously to us . . . the consequence was, the country throughout the whole survey was burnt, leaving my bullocks destitute of food. During the time I was on the range the lower parts of the country were burning . . . dense masses of smoke obscuring the horizon in all directions.13

  In 1788 these slopes averaged big fires every 50 years, but the 2003 fire may have been the hottest the valley ever experienced, because regular cool fires left fewer trees in 1788.14

  6. Eucalypts and acacias after a December 2001

  bushfire, Canberra, 31 August 2008

  Peter Greenham, Canberra. Compare pictures 3–4, 16, 18, 24, 28, 35, 40, 48.

  Southern Blue Gum and Cootamundra Wattle, exotics in this locality, compete to recover from fire. Southern eucalypts promote fire via highly flammable oil, leaves and bark (ch 3), recovering via beards and lignotubers (ch 1). Already taller than regenerating competition, they take
what light they need and block it from competitors, even their own beards. These saplings stand above competing plants, with enough light to branch evenly.

  After fire or drought most acacias regenerate from seed, densely and quickly. Before this fire no wattles grew here: for at least 30 years this was a eucalypt plantation. The fire liberated seed in the soil, so wattles crowd the gums, and unless another fire comes might overtop them. But they are short-lived, and in time the gums will outgrow their descendants, take the nutrients, block the light, and kill them. Seed then waits in the soil for another liberating fire.

  6

  Early settlers knew this. West of Sydney in 1834 Charles von Hugel noted:

  The woods assume a pleasing aspect here; Acacia decurrens and marginata, with their bright green foliage and their golden buds just forming, cover every open space in the many clearings, which have partly reverted to forest. It is most extraordinary how, in all those parts of the colony where these trees occur at all, Acacia decurrens germinates in every spot which has been cleared of forest and where the felled trees have been burnt, even where not a single tree of that species is to be seen in the vicinity. This led Mr W. Macarthur to conduct an experiment. He covered one half of a bed sown with various varieties of Acacia with brushwood and set it alight. This had the expected result. Whereas only a few seeds came up on one side, the other half which had been laid with twigs was covered in seedlings.

  This phenomenon appears to demonstrate that the seeds of the acacias of New Holland remain viable for a long time, but always require a high degree of heat in order to germinate. The same appears to be the case with most of the seeds of plants classed as ‘New Holland plants’ . . . These scrubs were subjected to regular firing by the Aborigines for so long that it would have been impossible for any plant to grow there without this characteristic.15

  Various acacia and eucalypt fire histories appear in early colonial art: hot fires (beards, dense wattle), cool fires (trees wide spaced), or no fire (several generations of the same species), while the ratio of eucalypts to acacias can convey how intense and how long ago a fire was. Banksia, casuarina, Mountain Pepper and others also display their fire history, so that artists painting soon after a 1788 fire regime ended often unconsciously depict it.

  Eucalypt recovery from fire or drought

  7. Orroral Valley, ACT, 1 September 2007

  8. Erudina Station, SA, 17 August 2007

  BG. Compare picture 9. For help with picture 8 I thank John and Sue McEntee.

  7

  Many eucalypts have a remarkable capacity: their bark heals their wounds and revives trees apparently dead (ch 3). Picture 7 shows a Ribbon Gum at an old hut site. It was lopped, dropped branches when boots and hooves compacted the soil, and seemed to die. The hut was abandoned; the tree revived. At left a lignotuber grows, and bark is re-clothing the old trunk. In time, a long time, bark and branch will conceal the scars as though they never were. Some eucalypts are much older than we imagine.

  Picture 8 shows River Red Gums (erudina) on Wilpena Creek floodplain on John and Sue –McEntee’s Erudina Station in northern South Australia. John stands at right. ‘Dead’ for decades, the centre stump was cut for firewood years ago, but began re-barking after 1968. In the background are ‘dead’ and re-barking gums. When the creek changed course in 1937, several miles of gums began to die, and by 1955 almost all seemed dead. In 1968 sand choke forced the creek back into its old course, and the trees began re-barking. By 2007 half the forest was back to life.16

  8

  Harold Cazneaux’s famous 1937 photo, Spirit of Endurance, shows a River Red Gum bark-regenerating near Wilpena Pound, west of Erudina.

  9. Eucalypt recovery from fire: Yelvertoft Station, Qld, 27 August 2007

  BG. Compare pictures 5–8, 14–15, 40.

  9

  This is pastoral land, patch-burnt as opportunity permits to bring on green pick. A recent fire has not touched background scrub, but foreground Snappy Gums have been burnt too often and are stressed. From their height in this dry country, they survived a fire perhaps 4–5 years before, and have just been burnt again. The contrast between green foreground and prickly background explains why pastoralists burn such land. In 1788 people had more room to rest country.

  Many of the ways in which eucalypts treat fire are shown. At left a tree was re-barking and growing a lignotuber before this fire scorched it, at centre a stump seemingly dead is re-barking and growing lignotubers, some with beards, at right lignotubers regenerate. Smaller trunks lean away from larger neighbours, and fire has killed mistletoe on the saplings at right. Of the trees this light soil might carry, only gums have survived the recurrent fires, and even pick vanishes near them.

  10–11. Kangaroo Grass near Berridale (NSW) (10)

  and in Canberra (11), late summer 2008

  BG. Compare picture 12.

  10

  Most introduced grasses are winter or spring flourishing annuals; most natives are summer flourishing perennials. Fire and drought kill annuals readily but native perennials rarely. This made native perennials invaluable: being perennial they re-shoot green when burnt, and being summer flourishing they feed grazing animals when drought is worst and fires most easily lit. Burning thus attracted the animals, and limiting the burn concentrated them. People burnt carefully, for perennial pastures also carried herbs, annuals, tubers and bulbs, each needing different fires.

  1788’s most widespread grass was Kangaroo Grass (ch 3). Its summer tan was Australia’s dominant colour in 1788. Under heavy grazing later it was reduced to refuges, but is now returning to destocked land. Picture 10’s dense swathe, ‘like an even, sweeping field of oats’ as Leichhardt put it in 1844,17 indicates land not heavily grazed. The lighter vestiges are Wild Oats, an introduced annual dead in summer. Picture 11 shows Kangaroo Grass green, dense and moisture shielding in late summer. Its myriad corkscrew seeds can pincushion kangaroo and bull hides, but Aborigines and early settlers burnt it every 1–3 years to lure and locate grazing animals.

  11

  12. Arthur Streeton (1867–1943), Golden

  Summer, Eaglemont, Victoria, 1889

  95.604, NGA. Compare pictures 10–11, 17, 57.

  This land near Melbourne (overleaf) has no stumps, and scattered trees lacking low branches and spreading narrowly, so they grew in forest. They pre-date European occupation, suggesting that settlers cleared the country.

  12

  The scene reflects how soon settlers upset Australia’s grasses. For over a century Impressionist paintings such as this, Streeton’s Near Heidelberg (1890) and Tom Roberts’ A break away! (1891) have declared the colour of Australia. They use glaring whites or creams to conjure up the heat and dry of summer, transforming earlier depictions which mimicked Europe by portraying the land green. They moved the common perception of Australia from other seasons to summer. Thousands of landscapes since have repeated their impression.

  They do not depict native grasses. Some do look white or cream in summer, but most look purple to tan. The first Australian grass named by western science, White Grass (Common Tussock), widespread in eastern Tasmania and the southeast mainland, has purple–tan seed heads, as do many other poa, while Kangaroo Grass seeds in dense tan plumes. By Streeton’s time that Australia had largely vanished. ‘Throughout most of the continent’, Curr recalled in 1883,

  the most nutritious grasses were originally the most common; but in consequence of constant over-stocking and scourging the pastures, these, where not eradicated, have very much decreased, their places being taken by inferior sorts and weeds introduced from Europe and Africa.18

  Introduced winter or spring flourishing annuals, dead in summer, replaced summer flourishing perennials. Golden Summer’s golden creams are colours of death. Conserving drought-shielding perennials took more skill than newcomers had.

  PICTURES 13–22: BROAD-SCALE FIRE

  13. Sydney Parkinson (1745?-71), A view of

  Endeavour River, Qld, July 1770<
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  an9193430, NLA. This picture first appeared in Hawkesworth vol 2, pl 19. Ignaz Klauber’s almost exact copy, used here because it is coloured, was for the 1795 Dutch translation. Compare pictures 13–31, 39, 42–51, 57–8.

  13

  This is Cooktown, where Cook beached Endeavour for repairs. It shows a very varied mosaic. On the mountain at right rear a sharp edge separates trees from grass, and the hill below is mostly grass. At right a dense shoreline forest gives way to a mere line of young trees, perhaps broken when Cook’s crew cleared a camp and got firewood. At left is an open shore. Hills and slopes carry tree lines or lanes, a feature much more common in colonial art than in the bush today (pictures 19, 20, 27, 38, 58). Careful cool fires made them.

  The hills at left carry Blady Grass in different fire recovery stages, some tall, some lawn, some between. It is a rapid coloniser after fire, and useful feed when young. On 19 July Aborigines set fire to it around Cook’s camp, and its sudden fury caught his crew by surprise. People were using an ally as a weapon, though July is in the dry season, when grass is still burnt to keep back snakes and to make pick.

  The hill at left still has Cook’s name for it: Grassy Hill. It is tree covered now. A plaque on it states, ‘The Guueu Yimithirr often burnt this hill to encourage a “green pick” and bring wallabies to the grass shoots. When the Wangarr (non Aborigines) arrived in 1873 burning was reduced. Tree seeds, carried by birds and the wind, germinated across the slopes. Grassy Hill slowly converted to woodland.’19 Parkinson shows at least two tree species on the hill, which may have been the seed source.