This is the second of a four-part article by BEC member GEOFF DAWE, regenerator consultant for the Cumbebin Wetland in Byron Bay.
Part 2: Strategy
Since weeds are co-regenerators, they are not considered to be part of the problem. Rather, the problem is the spaces between native trees, and a narrowed focus view that weeds are of little use.
Camphor Laurel for example is not seen as an invasive alien, but as a source of organic matter that has potential among other things, for food production.Tweed Shire councillor, Henry James has said that Tweed Shire Council landscape workers notice no difference in the growth of trees from those mulched with Camphor Laurel chip and those mulched with the chip of other species.
In small area farm production where orchard trees are incrementally introduced, chipping can be bypassed with the use of a chainsaw that cuts camphors into carriable lengths that are then placed around orchard trees. Beetles and other small animals add manure in the reduction of logs to sawdust over an extended period. Camphor Laurel has a significant ability to recycle potassium.
Native Tree Canopy
Weeds particularly in sun positions are extremely rampant, and so they need to be to protect soil. Chemical free weed control involves keeping weeds off natural regeneration trees and adding further trees in order to keep a native tree spacing of an arbitrary 2.7-3.0 metres which is considered presently to be optimal in providing canopy cover.
Chemical Free Weed Control
The Strategy is not focused on weed eradication. It is the native trees' production of a shading canopy that primarily does that. Weeds in sun areas are cut or pruned away from native trees so that the energy of the weed is not eradicated, and the native seedling selected above that of the weed.
There is an attempt to time return so that tree seedlings are covered by weeds, ideally no longer than a fortnight.
A stake and fluorescent tape are important because often trees can be lost among weeds. There is also an attempt to return as infrequently as possible and freshly weed covered trees do not appear to suffer knockback.
During the recent drought, it appeared that the encroaching weed canopy may have given seedling trees overall respite from the drying effects of no shade. Certainly a study on the survivability rates of trees devoid of surrounding vegetation and those growing within maintained weedscapes would tend to eliminate the potential for weed myths.
Seedbank removal not a priority
The attempt to remove seedbanks is regarded by this regeneration technique as 'pissing against the wind'. Weeds serve as indicators that land use techniques have been poorly considered. The problem is not fixed by simply eradicating the weeds or neutralising seed dispersal but by considering better land use techniques and in so doing, weed proofing lands.
Landowners should be aware that current conventional land use methods are involved in the process of 'killing off what wants to grow, and trying to keep alive what wants to die'.
A closed canopy native tree area does not tend to harbour weeds. Pasture areas that are made more fertile strengthen grasses so that they have greater ability to lock out weeds naturally. Fertile pasture lands in these areas are more often than not the flatter areas.
Grasses on hillslopes are often not enough vegetation, bare patches of soil emerge, and it is here that weed seed such as groundsel, mist & croften weeds take hold to add more biomass than can be offered by grass.
Hillslopes in these sub-tropical areas need re-treeing to prevent weed incursion. Roadside verges, as demonstrated by the RTA, can be thickly planted with suitable native vegetation to leave no niche areas for weeds. In all of these areas there is no doubt that weed seed is on the ground, but if the land area is used correctly with regard to increasing organic matter levels (OMLs) the seed does not tend to germinate.
The seed that is on the ground lies there as an indicator; a warning of deteriorating land use and movement against it, is in effect, a movement against NatureÆs emergency response.
Easily let go of Principles
Nature appears to take delight in its insistence upon diversity to such an extent that it tends to create exceptions to all rules.
Chemical free weed control is an evolving process involving observation and experimentation with every regenerator able to offer more constructive ways. Madeira vine, for example, presents a problem with the general principle that seed bank removal is not a priority.
At present we tree at close spacing with dense canopy, shade-loving trees on the perimeter of severe Madeira growth areas in the hope that future layered canopies may produce extremely low light levels that prevent Madeira germination. We have no idea whether this will work or not.
In the meantime with new or minor infestations, corms and plants are removed according to conventional regen. methods. There is also a tendency not to eradicate weeds, but since weed hatred appears to occupy some workers presently, there is not an insistence on cutting weeds rather than pulling them out. It is not definitive answers that are sought, but balance.
Letting go of eradication: Noticing and using the Energy of Weeds
All weed species have a beauty as well as a difficulty, so does everything else on the Earth. Chemical free bush regeneration involves going with the beauty of a weed so that it is not nullified, and using its difficulty to select in favour of native vegetation. As to how that happens, requires a focus in turn on particular weeds at Cumbebin.