Bush Regeneration
Restoration of degraded areas of natural vegetation is a daunting task that often defeats the resolve of even the most dedicated environmentalist. A method that has become popular in New South Wales, particularly, is the "Bradley Method of Bush Regeneration". This has proven to be extremely effective and has been taken up by both government agencies and community groups. Its main drawback is that it requires patience; immediate gratification cannot be expected.
The method was developed by sisters Eileen and Joan Bradley and is based on allowing the native plants to re-colonise areas following, mainly, hand clearing of weeds. The following article from the December 1983 issue of "Native Plants for New South Wales" (newsletter of the Society's NSW Region) outlines the basic methodology. The methods have not changed appreciably over the years and still produce outstanding results.
Regeneration of the Bush
Based on a lecture by Evelyn Hickey to the Society's North Shore Group
The names Eileen and Joan Bradley are of course synonymous with bush regeneration. These pioneers came from a family of scientists and they themselves followed that tradition in an era when women were not generally accepted in that field. It is not surprising therefore that they turned out to be the persevering ladies they were. They were employed by the National Trust in 1976 to train workers in their techniques to work at the Blackwood Sanctuary.
They started out with 3 people! The Trust now employs 75 workers, advising 13 municipalities, governments and private concerns, and is constantly training new recruits -- quite a success you might say.
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The Mystery of the Method
The greatest mystery of the whole Bradley method is that no-one knows why it works -- it just does! Its advantages are:
- It works
- It is economically sound
- It encourages a more diverse plant community to establish itself.
Its disadvantages are:
- It requires skilled workers
- It takes a long time
- There is only a subtle change -- no dramatic changes occur.
Basic Principles
To quote from the National Trust pamphlet on the Bradley method, the basic principles are:
- Work from the least weed infested areas to the most densely infested. In the least infested areas there are abundant native plants and seed to colonise the area from which weeds have been removed. In the dense weed infestations, the number of weed propagules far out number native propagules so weed growth rather than native plant growth is favoured.
- Minimise soil disturbance. This includes replacing top soil in its correct position so that the stored seed is not buried too deeply and keeping the soil deeply mulched.
- Allow native plant regeneration to dictate the rate of weed removal. Native plants which regenerate must be allowed to form a dense and healthy group before the adjoining weeds are removed. These natives can then successfully colonise the newly weeded area. If too large an area is cleared before native plants are capable of colonising it (over-clearing), weeds will successfully compete with native plants.
The Temptation
It is tempting to make a spectacular effort and remove an eye-sore of introduced plants from along a track or creek. This leaves the area open to the regrowth of more of the same type of seedlings and, worse, the introduction of quick-growing, free-seeding introduced plants. These work their way deeper into the bush and widen the weed boundary. Further effort spent on the removal of these plants simply compounds the mistakes.
If, on the other hand, the bush behind the weed-barrier is strengthened, work can be carried out on the basis of working from good to bad and specific areas of introduced plants can be removed so that the strong bush can move in to replace them. It is all very subtle and requires a great deal of patience. By tipping the balance of power towards the natives, weeds will be inhibited and finally eliminated so that very little attention need be given to the area ...possibly a follow-up once every year or two.
The disadvantages are mostly those of human impatience. The method cannot proceed faster than the native plants regenerate. One should not expect the bush to return to a weed free state overnight as it has taken many years to reach the weed infested state.
An example is the "Wingham Brush" -- an area of rainforest on the north coast of New South Wales. It is estimated that it will take 20 years to return the Brush to itself, but fortunately the local Government body has had the wisdom to support the Bush Regeneration program and has been converted to the fact that, while it will take time, this tourist attraction will eventually return to its original state.