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Bringing Back the Bush
The story of bush regeneration probably began as far back as 1957, when Eileen and Joan Bradley commenced their study of the Superb Blue Wren, several families of which lived in their garden and the neighbouring bushland of Aston Park and Chowder Head, both now part of Sydney Harbour National Park.
After the study was published in "The Emu" the following year, they turned their attention to the wrens' habitat which was becoming increasingly degraded. The managing authorities were diligent enough. They slashed, chopped, mattocked, raked and burned what was left or carted it away. The clearings were then planted with native shrubs and trees, often not the species of the area.
The result of all this labour was a regrowth of the same weeds or a succession of quick-growing, free-seeding weeds....or both. The volunteers who undertook the follow-up became discouraged by the never ending appearance of the weeds and finally gave up; most of these plantations were utter failures.
It was obvious that there had to be a better way.
Change to Vegetation
The sisters used to take their dog for daily walks through the reserves, picking out weeds as they went along. As time went by they noticed that native species were replacing the weeds they had removed.
This encouraged them to weed more systematically and to note the results.
In the early sixties they began vegetation surveys and species lists: they weeded, logged every plant they pulled out, every plant that came up and every hour that they worked.
At the end of three years they had sufficient data to write "Weeds and Their Control".
A Change in Aims
During the following four years, the initial aim to control the weeds was translated into something a little more ambitious.....to bring back the bush.
When "Bush Regeneration" was published in 1971 (under Joan's name), their records and observations revealed an ecologically sound way to approach the problem of weed invasion and that the bush could be coaxed back to health and stability with little physical effort and without the doubtful benefits of cultivation.
The 'Bradley Method', as it is commonly known, is as much a philosophy as a set of principles and a variety of weeding techniques.
|"The 'Bradley Method', as it is commonly known, is as much a philosophy as a set of principles and a variety of weeding techniques."|
It requires the aspiring regenerator to put aside all sense of creative self, as exemplified by the landscape architect or the bush gardener, and to do all things necessary to encourage the existing indigenous species to spread and to provide favourable conditions for the germination of native seed in accordance with the habit of centuries.
What it is not, is a determination to exterminate the enemy . . . the weeds.
Priority is given to helping the bush to help itself. It may come as something of a surprise to learn that there are times when weeds can be regarded as friends.
The Three Principles
The three principles which guide the mind and hands of the regenerator are:
The first principle argues a need for some knowledge of botany. It's not necessary to be a botanist (although it helps). It's not even necessary to be able to reel off the Latin names fluently, but it's absolutely essential to be able to distinguish a weed from a native species.
- Always work from good to bad areas.
- Disturb the soil as little as possible and restore it to its natural condition .
- Allow the rate of regeneration to dictate the rate of clearing.
That degree of skill is basic to site assessment; without it, it's not possible to determine which are good or bad areas or to estimate the chances of regeneration.
The second principle recognises the fact that disturbed ground favours the growth of weeds. It would be irresponsible to claim that the Bradley method creates no disturbance at all. It does, but it is minimal if the weeders discipline their feet, apply the techniques efficiently and replace soil, humus and mulch (right side up) in their natural order.
|"If a passer-by remarks 'What a lot of work you've done!' - you know you've failed the second principle"|
Before leaving the site, all trace of human activity should be obliterated. Except for the weeds draped around as extra mulch, or. in the case of vigorous re-growers, hung in the nearest natives, the casual observer should not be able to tell that any work has been done. If a passer-by remarks "What a lot of work you've done!" -- you known you've failed the second principle.
The third principle is probably the ultimate test in patience. In bush regeneration there are two kinds of time; working time and waiting time. Working time includes the primary clearing and follow-up sessions.
The second kind is the time spent in waiting for the native species to emerge and stabilise the weeded area. This time costs patience.
This may not be of much consequence in the good areas, but as the primary clearing moves into the thicker weeds, the rate of regeneration slows down, so the rate of clearing must be reduced to match.
Many an enthusiastic weeder has ignored this principle and has paid the price ... tiresome and unnecessary follow-up, discouragingly slow regeneration or none at all . . . and a shattered morale.
Wherever an artificial boundary is flung around an area of land it has to be managed, but before it can be managed, detailed information of the site has to be collected, analysed and evaluated.
In the case of bushland, vegetation maps and species lists of both the indigenous and exotic plants are essential. Soil types, terrain and neighbouring uses should be broadly noted and some observations made of the animal population.
A little of the area's history is useful and may explain why some spots are threadbare and others healthy. It may also give some clue to the presence, if any, of a viable seed bank in the ground.
In the metropolitan bushland reserves, where most of the regeneration programmes are being carried out, the vegetation surveys broadly define four classes of native to weed ratios. They are:
There is a fifth class. This includes previously cultivated areas, such as encroachments by private gardens, borders and entrances to reserves which are so depleted of indigenous species that they can't be classified as native bushland.
- Good Condition: native bush with scattered weeds.
- Fair Condition: two to one native to weed ratio.
- Poor Condition: weeds abundant, outnumbering the natives in a ratio of seven to three.
- Very Poor Condition: thicker and thicker weeds finally reaching complete replacement of the native species.
Commissioned by National Trust
Decisions on management and plans of work can only be reached when this information has been processed. When, in 1976, the National Trust decided to use the Bradley Method in one of its own properties, the Blackwood Memorial Sanctuary, Beecroft, it bought the whole package, management, principles and techniques.
Joan Bradley and I were employed to train a small team which, luckily, included a young botanist, who dealt with the survey and plant list and saved us many trips to the herbarium. Where the Bradley's records of man-hours spent hadn't convinced local government authorities that bush regeneration was an economic alternative to their conventional methods
of clearing weeds from bushland, the figures the Trust produced did.
After four and a half years of working in Blackwood, the Trust was able to estimate that the cost of bush regeneration (per hactare) over a five year period was approximately one-tenth of the cost of one municipal solution-- clearing followed by mass planting. That kind of comparison was hard to ignore and although local councils didn't rush the Trust for surveys and teams, a steady stream of enquiries began.
Having said all that, I must now admit that the very first council to take the plunge, did so quite independently of the Trust's attractive figures. Early in 1978, five months after a bushfire had swept through a part of Warraroon Reserve, Lane Cove Council offered Joan and me a contract to employ regenerators and deal with the burnt area.
The fire was not the only reason for the council's decision. there was a strong feeling in the Lane Cove community that the bushland reserves were not improving under conventional methods of clearing and that the Bradley Method should be tried.
The Warraroon Reserve
The Reserve is a fairly typical example of urban bushland but it has some special features which give it a character all its own. It suffers the usual hydrological problems surrounding developments (roads, houses and stormwater pipes) and internal structures like a scout hall and the sewer, with its attendant vents and inspection eyes, along the length of the creek.
The disturbance caused by providing these human amenities created favourable seedbeds for opportunist weeds so, as could be safely predicted, the perimeter of the reserve, the edges of the curtilage of the scout hall, the banks of the creek and the edges of the paths all supported walls of weeds of varying widths and densities.
Two pluses in our favour were the variety of plant communities, from rainforest to mangrove, and the 1978 fire which must have been very intense because it left a fine grey ashbed, highly
mineralised and very fertile. Both natives and exotics shot up in their hundreds.
For the weeders, it was a race to remove the exotics before they engulfed the natives and the minerals lost their punch, usually estimated between 18 months and three years. In this case, the effects of the minerals lasted well over two years. By that time the natives had the
upper hand and were beginning to compete with each other for the nutrients .
By 1983, the burnt area was stable and only required maintenance checks about twice a year.
That kind of dramatic response doesn't often come our way. More often it is slow progress. Of course, neither result could be effected without the trained regenerators and their skills in
handling the tools and applying the techniques.
|"....bush regeneration is
not a recipe for instant bush."|
The Tools Chosen
The tools have been chosen for their relevance to the principle of disturbing the bush as little as possible. First come the fingers; they are used for the delicate work of twiddling and pulling tiny seedlings etc.
Then there are the small hand tools; a knife, a pair of anvil-headed secateurs, a fern trowel and a small pair of pliers. These are carried in separate sheaths or combination pouches, hung on a belt and worn on the person. Just about every weed can be dealt with by these small implements.
Some exceptions are the large woody species like the two privets, camphor laurel and the very largest of the lantanas. For these you need bigger tools carried on toolboards. These are the long-handled, anvil-headed loppers, a hatchet, a folding saw, a tiny wood saw and the latest addition, a type of jemmy.
Other items carried on the toolboards include sharpening stones, oil and oily rags and a first-aid kit.
With each person equipped with hand tools, the toolboards are sufficient for a team of eight weeders....plus the necessary 10x lens, calico bag for weeds, plastic bag for specimens and a plant press.
Clothing may not seem terribly important and it is largely a matter of choice if you wish to bare your limbs to the savagery of lantana, blackberry or bursaria.
However, two items of apparel do need some thought, gloves and footwear. Gloves should be well-fitting and pliable, fairly tough but thin enough to allow the sensitivity of the finger-tips to feel the stems of small plants. These are made of very soft leather and are available in men's and women's sizes. They're not perfect but they are the best on the market for the purpose.
Even more important is the choice of footwear. The first technique a trainee learns is not how to handle a tool, but how to walk in the bush.
Both men and women are expected to step lightly and to avoid treading on the natives, scuffing or compacting the soil. There's not much point in attempting to bring back the bush if at the same time the emerging generation of natives is being flattened by the human macropeds.
So to help mitigate the impact, footwear should be light, soft-soled, pliable and well-fitting. It's difficult to maintain your balance while tippytoe-ing through the ground cover if a tight shoe is crunching a bunion or a loose one is going in the opposite direction from your foot! Old crepe-soled shoes, sandshoes with lightly scored soles, or very old desert boots with the sharp edges worn off are ideal. But, please, not gumboots or those joggers with soles like the tyre treads of a scrambler bike!
Technique -- Light as the Tools
The techniques are designed to create as little disturbance as possible. I'm not going to attempt any detailed explanation of them here, they're much better demonstrated in the field. It's enough to say that for those who are prepared to apply them with care and patience the rewards can be very satisfying.
My first experience of this came after removing a blanket of buffalo grass and six months later finding that it had been replaced by a carpet of "Nodding Greenhoods". Rough handling could have scattered the orchid bulbs, separating them from the mycorriza with which they share a symbiotic relationship, and it's unlikely that they would have survived.
The Bradley method has application to any native stand of bush where weeds are causing problems. I hope I haven't dampened your ardour by repeated references to care. discipline. caution and calculating progress over years rather than months. But bush regeneration is
not a recipe for instant bush. Rather it's a systematic way top restore and maintain a native plant community through natural regeneration.
Reprinted from the August and October 1985 issues of "Native Plants for New South Wales", the newsletter of SGAP's New South Wales. The article is based on a talk given by Toni to the Society's Hawkesbury Group in December 1984.
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Australian Plants online - December 1996
The Society for Growing Australian Plants