Tuesday, 14 July 2009

UNDER FOOT: An Ecology of Lawns

There's a unique feeling of betrayal being the first to mow your lawn in the spring. Slowly the flat, matted mass of grass has stirred itself and reached to heaven till it can be ignored no longer.

But to be the first who heeds the call is not to endear yourself to neighbours who drive past as you decapitate the winter crop. The feelings of disapproval are palpable. You imagine the nudgings and promptings of the non-mowers in the cars."... which reminds me, isn't it time we cut our lawn?" It's a royal plural, but the grunting work will be peasant singular. And - gender equity notwithstanding - usually masculine. Hence the dark looks from my fellow males. I try to keep my eyes down.

But if the mass of living things found in the grass could look at me darkly they would too. Their tangled jungle is being brutally clear-felled. A wolf spider turns from hunter to hunted; a sleeping hawk moth flutters into life barely in time; there is mass exodus before the roar of the rotary mower.

The rotary lawn mower is Australia's gift to the backyards of the world, able to cut tall poppies with nationalistic indifference. Invented by Mervyn Victor Richardson in the early 1950's, he modestly patented the name "Victa" for it. Between the rotary mower and that other great Australian rotary invention, the "Hills Hoist", Australia has the backyards of the world marked out and tidied up.

Yet there is a futile territoriality about lawns. They are meant to tell something about us; certainly to say "this is mine", but also to display something of our command over nature. Lawns had come to prominence in Europe during an era in which the garden, for the rich, was the place to display the manipulative brilliance of human intelligence. Hedges, shrubs, and even trees were also shaped with this illusion in mind.

The property illusion created by lawns was taken to an amusing extreme by 18th century English landscape gardener William Kent, who frequently employed the "ha ha" fence. This consisted of a trench in the lawn at the boundary of the property. The trench could contain a stock-proof fence, but because it was hidden from view, the illusion of expansive holdings was maintained, even when the actual acreage was modest. Ha ha indeed!

Nature too laughs at our lawns, for grass provides only a Claytons mastery over our local environment. Even the best kept lawn is shared with hundreds, thousands, millions of crawling, creeping, flying, digging, sprouting, budding, living things, whether we know it or not. Try missing a few weekends of spring mowing and you'll soon see.

Still the illusion of ownership runs deep. I transgressed such a boundary as a child in Sydney. It was the drama of a cicada's death that made me forget myself. The insect called in alarm as a bird made a first unsuccessful snatch at it. The cicada was what we called a flowery baker - a large mottled brown and cream insect popular as a collected specimen. Firmly on the cicada's side, I followed as the bird made a second, this time successful pass. On the lawn in front of me the living, flapping, singing insect had its abdomen removed and ingested by the bird. The rest was discarded like a nut shell; a shell with face and wings and still-moving legs.

As I moved closer to confirm the grisly sight, a loud harrumph startled me. A woman was standing on her landing, rake held like a stave, a fierce and outraged look in her eye. It was only then that I saw I was on strange territory - her lawn. Knowing it would sound lame, I still wanted to tell her about the cicada; how its seven years beneath the ground had ended like this; how its passing seemed worth marking. But her look gagged my explanation. It was simplest to turn and run.

On other childhood days we would seek out the shilling-sized holes in our own lawns and flood them to try and bring the cicadas out. We reasoned that all those years in the nymphal stage wouldn't be hurt by staging a bogus summer flood. And up they would come like spirits from the grave - scarcely in the same form as the creatures they would become. A stiff but sodden brown caul held them prisoner still. Yet given time and careful handling they would dry out and soon begin their amazing metamorphosis. We would never tire of this unveiling, fascinated as much by the metaphysics as the physics, even if unable to articulate it. When it was all over we took the empty shell as a talisman.

In Tasmania our lawns are more subtly pocked by moths, but with a far greater impact. Moths are a winged metaphor for the power of fragility. They neither rip nor roar, yet their presence in the history of decay ranks with rust and Attila the Hun. Helen of Troy may have had the face that launched a thousand ships, but moths have the wings that tattered their sails.

Two ghost moths of the Oncopera species have Tasmania's grass divided between them. They are better known at their larval stage as corbie grubs, or just corbies. The winter corbie (Oncopera intricata) is more common in the north and north-west of the state. As a moth it is small - about march fly sized - with an unassuming mottled brown appearance. It is the larval stage of the moth that is notorious. During winter and spring the grubs of this innocent-looking moth come out at night to feed on grass. Patches of dead pasture and telltale vertical tunnels are the giveaway. They are so prolific that pasture damage has an economic impact.

Another small moth, Oncopera rufobrunnea - commonly called simply "corbie" - has an impact that is better known to the lawnmakers of southern Tasmania. Again it is the larval stage that causes the damage, hatching in our lawns as winter days lengthen into spring. Just how prolific they can be was discovered by a lawn-proud friend who offered his children ten cents a grub. A few tubs of water and detergent later they had relieved their father of nearly $50.

Australians are not the only people to be obsessed with neat green lawns. Czech playwright Karel Capek, writing in the late 1920's, chronicled the same kind of fixation among the gardeners of Prague.

As for us, owners of small gardens in town, please do not think that one dewy
morning we shall whet the scythe, and then with open shirt, with powerful
rustling sweeps, and singing popular songs, we shall cut the sparkling grass.
Things are rather different with us. First of all we want to have an English
lawn, green like a billiard cloth, and dense like a carpet, a perfect lawn, a
grass plot without blemish, turf like velvet, a meadow like a table.

There is a comforting familiarity in Capek's unfolding account of his lawnmaking efforts, found in his delightful but out-of-print classic 'The Gardener's Year'.

Well, then, in spring we find that this English lawn consists of bald patches,
dandelions, clover, clay, and a few hard and yellow tufts of grass. When weeded
all that's left is a waste land, trampled, and as bare as if bricklayers or a
herd of zebras has been dancing on it. Then it is watered and left to crack in
the sun, after which we decide that it really needs cutting.

There are many other ways to create holes and bare patches in grass. Its green sward is subject to attack from claw, fang, hoof, tooth, turd, mold, micturition and much more besides. At home our grass becomes the community noticeboard for the territoriality of mammals. Dogs and possums both scratch marks in the grass, telling others of their species how large, strong or virile they are. Dog urine is another notorious patch-maker. An overdose of ammonia quickly yellows then kills grass.

Other lawn holes have other causes. The introduced blackbird (Turdus merula) and the native White's thrush (Zoothera dauma) have similar aims in making holes in the lawn. Both are searching for earthworms and grubs. Having seen them at it often enough I'd thought an unusual frequency of holes in my grass was their doing.

But the shape of the holes was wrong. A blackbird probes a very small hole, only enlarging it if the prey is large or stubborn. The holes in question are all large, a few centimetres deep, about the same wide, and distinctly conical in shape. The scats (droppings) behind a few of the holes help to identify the culprit. It's the work not of a bird at all but of a native mammal, the eastern barred bandicoot (Perameles gunnii). This small insectivorous marsupial is considered rare and vulnerable in mainland Australia - with only a few established colonies in western Victoria. In Tasmania it is plentiful enough for some people to complain about the pasture or lawn damage it causes. To me it is a privelege to have their holes in my lawn!

It is one thing to know bandicoots are about, another to actually see them. The presence of an introduced grass helped me here. Though most of our grasses are immigrants, one that is no longer welcome is pampas grass. This hardy and invasive South American grass grows into enormous clumps that can spread into the bush.

But removing them is no light work. After a solid day with a mattock and spade I remove the last roots as dark falls, then retire into the house for refreshment. Sitting, drink in hand, by the window, I am not far from the hole that was a pampas plant. Suddenly a slight movement catches my attention. Something snuffles through the newly dug earth. It is about as long as my boot, and has noticable pale stripes down its grey/brown body. It moves cautiously and quickly to enjoy the feast that has just been laid on for it. I don't know which of us is happier.

I gradually discover that in my local area bandicoots are almost plentiful. Scottish gorse, another introduced and rampant weed, gives bandicoots improvised cover from the cats and dogs that are their most dangerous enemies. But in my yard they seem to have taken up residence in a large clump of New Zealand mint, with only faint tunnels and occasional scats to give away their presence.

More formal bandicoot studies in Tasmania have shown that they have a surprisingly varied diet. Most commonly they feed on the invertebrates they dig from the soil, including corbies, earthworms, crickets, beetles, slaters and spiders. But at times they'll feed on whatever else is available, including fungi and fruit.

In my yard they seem to get plenty of everything. Beneath the brief layer of green that passes for lawn, there are rich pickings. The introduced lumbricid earthworms that tend to dominate pasture and lawns can breed at an amazing rate. Where conditions are right, such as with an increased input of water and nitrogenous matter, worms can reach population densities of nearly 1,000 per square metre - making grass and lawn a bandicoot heaven.

But we are not the only ones to make lawns. In parts of the state, native animals not only benefit from lawns; they actually create their own. Two of our national parks, Mount William and Asbestos Range National Parks, were once grazing properties. When introduced grazing stock was first excluded from these parks, it was expected the pasture would revert to bush and forest cover. Though this happened to some extent, large parts of the parks have remained free of shrubs, giving the appearence of closely cropped lawns. In effect that is what thay are - marsupial lawns. Even in the wilder parts of the state, wallabies, wombats and other native animals favour grass over bush, creating clear grassed areas by and for their own grazing.

All of this may help us to imagine that grass has always been here. Yet geologically speaking it is a relative newcomer. Only during the last 10 - 15 million years has grass been at all common in Australia. Before that rainforest tended to dominate the vegetation of our once wet continent. It is only as the continent dried out that grass became widespread, which is a nice irony when we consider how much water we pour annually onto the (imported) grasses that make up our compulsorily green lawns.

Even those marsupials that don't directly eat grass may end up depending on it. So it is with the mountain pygmy possum (Burramys parvus). These tiny marsupials travel long distances to feast on bogong moths in the Snowy Mountains.

The larval stage of the bogong moth (Agrotis infusa) is the cutworm whose love of grass causes major pasture and crop damage over inland Australia. Once fattened up on grass, the larvae metamorphose. Then each summer the moths migrate to the Snowy Mountains, where they congregate in large numbers in crevices and rock shelters. They rest together (aestivate), overlapping one another in a single layer of up to several thousand individuals. While in the mountains they neither feed nor breed, but through this summer at rest they avoid the sparsely grassed and inhospitably hot inland.

Historically bogongs were also a target for Aboriginal groups, who cooked and ate vast numbers of them in annual highland feasts. The fat content of moth abdomens is supposed to be remarkably high, so it could be said that both humans and burramys lived off the fat of the land. And all thanks to the humble grass we tread underfoot.

Woken by Woodpeckers

[a travel piece about the Adirondacks published in the Sunday Tasmanian, late 2000]

It is dark. I am in an unfamiliar room in one of the world’s most violent countries. A sound startles me out of sleep. Is that a door creaking? I open one eye, but the sound stops. Then, closer still, another door creaks, then another, until the room seems under attack from all sides.

Before complete panic takes over, I remember where I am, and start to guess what the strange creaking sound is. My “attackers” are none other than woodpeckers! Or to be precise a combination of woodpeckers and yellow-bellied sapsuckers tapping away in the adjacent woods.

I am staying at a woodland retreat in the Adirondack Mountains in the north-eastern United States. Though just a few hours up the road from New York City, the Adirondacks (said Adder-RON-dacks) contain some of the wildest country anywhere in the USA. It is a loosely defined region of mountain, lake and forest, a vast area of wild country fringed by towns and low-key resorts favoured by New Yorkers wanting to get back to nature (or "head to the woods" as they might say).

That's in summer at least. In winter the region is more likely to be invaded by skiers, with areas like Lake Placid famous for its ski slopes and cross-country trails. The 1980 Winter Olypics were held here, and the US Winter Olympic team still trains here.

Most of the Adirondacks is contained in the Adirondack Park. At 6 million acres the Park is bigger than Yosemite or Yellowstone or most other parks in the USA. Though it has never achieved National Park status, the park is afforded virtually the same level of protection. So the moose, bears and beavers found here are as safe as they can be anywhere in this heavily industrialised nation.

It wasn't always so. During the 19th century the Adirondacks was the scene of widespread devastation as huge tracts of forest were cleared for their timber, and roads were driven into country that was so wild even the Native Americans had seldom visited. The name “Adirondack” appears to be based on a native American word meaning “bark eater” – a possible reference to their belief that, in comparison with the rich hunting lands nearby, the Adirondacks would only support people who could live off the bark of trees!

Certainly trees were the main resource extracted from the area through the 19th century. It wasn't until the late 1800s, with the support of President Roosevelt, that it was realised the same trees were worth more when left for wildlife and tourism. New York State finally declared that the area "shall be kept as wild forest lands" forever. At the time that declaration was wishful thinking, given the extent to which the forests had already been logged. Yet a century or so later their dream is a remarkable reality. The wild forests really do teem with wildlife, and people from all over the world come here to share the natural wonders so close to some of the world's biggest and busiest cities (including New York, Boston and Montreal).

For a Tasmanian in the States for the first time, there is a cartoon-induced unreality to meeting the local wildlife. Just as people's “knowledge” of Tasmanian devils is often derived from "Taz", the cartoon character, so too was my knowledge of woodpeckers, skunks, bears and beavers rather too closely modelled on Warner Brothers and Hanna-Barbera. With the expert help of local naturalist and author Ed Kanze, I am soon put on the right track. I learn, for instance, that beavers are strong and powerful animals, and considerably larger than I had thought (weighing perhaps as much as a large dog.)

I visit a pond and wetland that has been created by beavers damming up a stream with the trunks and limbs of some sizeable trees that they’ve downed with their own teeth. It is a feat of engineering far more serious than you’d expect of the cute toothpaste touting "Bucky Beaver".

Ed then shows me a pileated woodpecker, a bird about the size of a rosella, and pretty much the model for "Woody Woodpecker". I learn that their tapping noises are not for nest construction purposes. The male woodpeckers use pecking as a territorial sound – in lieu of vocalised calls. When they build nests they do peck out hollows in tree trunks, though then they choose softer wood, and the nest building is a much quieter exercise.

One of the other delights of the area is the canoeing, with dozens of streams and hundreds of fresh water lakes accessible to paddlers. The lakes result from the extensive glaciation of the area during the last ice age. New York’s Long Island is itself a vast terminal morraine, marking the point where the bulldozing glacier finished its work.

Whatever the cause the result for the adventurous canoeist is a network of lakes and streams on which it is possible to paddle for weeks. At times it seems that every second car in the Adirondacks has a canoe strapped on. We stop for a paddle on one of the remote forest-fringed lakes, and I soon begin to understand the attraction. It comes as no surprise that James Fenimore Cooper, author of “The Last Mohican”, spent a lot of time in this region. In such a place it isn’t hard to picture yourself living back in those times.

Just out of the Adirondacks, in the neighbouring Green Mountains of Vermont, I visit the backwoods cabin of another famous local author – the poet Robert Frost. Best known for writing “The Road Not Taken”, Frost spent many years teaching at Middlebury College in Vermont, retreating to this cabin for much of the summer to think and write. Today the log cabin is virtually as it was during the 1950s and 60s, when Frost frequented it. Surprisingly it isn’t sign-posted, and it is only through luck and persistence that we locate it at all. It seems the locals are happy for it to remain a road less travelled.

In a week I felt I scarcely scratched the surface of this delightful region. I reached the top of only one mountain – and there are 46 of them over 4 000 feet! And though I was lucky enough to see a black bear in the wild, I didn’t get to meet a moose or confront a coyote. I guess there’s always next time.

An Ascent of Mt La Perouse

Through a quirk in geology, the long ascent of Mt La Perouse begins atop one of Australia’s longest descents. Exit Cave worms its way 23km into the Ordovician limestone beneath these Southern Ranges. Lesser holes pepper the forest and unwary walkers in this wild area have disappeared without trace. But such chilling thoughts are soon distracted by the steepness of the uphill walk. It is all climb, through still, damp and overwhelmingly green forest. The hue is not just on the mossy forest floor or in the leaves but at every level, from roots to trunks to branches to fungi. There are fluorescent greens, sombre olives, glaucous blue-greens, lively gold-tinged greens and deep sea greens. The very air has a greenish tinge.

But thoughts of colour are unlikely to distract you for long from the relentless climb. There is nothing to do but hoist and haul yourself between, through, around and sometimes over the trees. After an hour, perhaps two, of sweat-raising effort you may sense a change in the air, and notice a change in the scale and type of trees. As you break out of forest and into a more open tea-tree and paperbark scrub, there are glimpses of the distant coast. The scent of decay-tinged damp is replaced by a sharper, cleaner air that somehow smells blue. After the shy light of the forest the sun here can be blindingly bright. If the day is calm – and sunny, calm conditions are not the norm here – you may find yourself sharing the air with a myriad flying insects: beetles, dragon flies, butterflies and a host of diptera. Most won’t trouble the walker, though march flies may show an interest in any exposed skin. As will leeches.

Although the scenery has changed, the incline of the track has not. And the more open going is countered by sections of deep mud that stand between here and the blandly named Hill 1. By the time you have trudged up to this bald, wind-battered eminence, you will have gained nearly 800m in altitude as well as a good thirst. While you take your break, the other bare hills of Moonlight Ridge are still ahead. By blunt logic these are named Hills 2, 3 and 4. But they are dwarfed by the majestic mountains that start to dominate the scene above: the Hippo, La Perouse, the Cockscomb.

Geological dramas from many eras have helped create the landscape around you. Even in (geologically) recent times – the last couple of million years – glaciers calving off Mt La Perouse and nearby peaks have dozed out deep valleys, gouged cirques, deposited morraines and left resistant rock standing above the fray. In the last several millennia, although the glaciers have gone, wind, water and ice have continued to chip away at the landscape. As you traverse Moonlight Ridge and close on Mt La Perouse itself, you climb through sedimentary rocks scraped almost clean by glaciers. First are the often softer Permian siltstones, then the more recent Triassic sandstones. Downvalley to your left Arndell Falls plunges from a cliff at the edge of a later dolerite intrusion. Although it’s tempting to leave the track here and head straight for the growing bulk of Mt La Perouse, the more oblique approach via the Pigsty Ponds is far easier. Just as you start to climb from these morraine-dammed lakes onto Maxwell Ridge, a cairned route to the left leads you up the long humped slope to the remarkably bare and flat-topped “peak” of Mt La Perouse.

The sandstone here was laid flat on a sandy plain, and despite all the ructions of the last 200 million years, remains remarkably flat to this day. If you were inclined to celebrate your ascent with a football game, the top of La Perouse would not look out of the question. But the winds that blast here most of the time, and prompted walkers to build a massive (and sheltering) summit cairn, would rule out most forms of football most days of the year. A quick and grateful look towards the indented coast; a peek over the edge towards the classic cirque lakes called Swallows Nest Lakes; an admiring photograph over the striking doleritic Cockscomb; a quick celebratory drink; these would be the best you could ask of La Perouse, even on a good day.