Although indigenous woody weeds are an improvement on introduced woody weeds it is debatable as to how much better. There is no doubt, however, that it is much easier to return an indigenous woody weed patch into a wirra than it is with its introduced cousin.
The point is that any plant species, if given the right conditions, can take over an area and smother all other growth. It is also fairly easy for an area of any woody weeds, indigenous or introduced, to deteriorate into a fire managed regime where each wave of weeds is totally destroyed by wild fire to again return to nothing but woody weeds.
Note that I use the term “wild fire” rather than “bush fire”. I do this deliberately because I believe that bush burning is a symptom that that bush was not being managed properly. There is no place for fire in a properly managed wirra.
Suppose you are lucky enough to select a block for your wirra that contains no introduced plants or that you have managed to remove all the introduced plants from your wirra. Suppose then you just manage your wirra to ensure any introduced plants that do return are removed. As you then monitor your wirra, you will notice that once the biodiversity has reached its peak, it will then gradually reduce.
After about ten years this reduction will become very noticeable. After twenty years there will be very little left other than indigenous woody weeds. This is because the events that are necessary to keep your wirra happy are no longer happening.
When you notice a decrease in biodiversity it is time to get out your lawnmower or slasher. It is time for you to do a bit of “eventing”.
A word of warning here however. Firstly you should ensure you do not ruin something you had rather not. For example if there is a species in very small numbers, it may be better to leave them so they can continue building up their seed-bank. It is also a good idea to leave a few of each species for insurance purposes.
Secondly it is good idea to start with a fairly small area. Pick one where biodiversity is lowest. Only do an area you are confident you can manage. You should get an explosion of growth. Much of it may be introduced rubbish you do not want. Do not get your lawnmower out again till you have the first bit under control again.
A list of Wirrapunga indigenous woody weeds are given below. These will all need some control.
Acacia myrtifolia
Acacia pycnantha
Acacia verniciflua
Daviesia leptophylla
Exocarpos cuppressiformis
Grevillea lavandulacea
Hakea carinata
Hakea rostrata
Leptospermum myrsinoides
Pultenea daphnoides
Pultenea involucra.