Philip Murray outlines his experience in undertaking a bush regeneration project on his Rosebank property. Phil gives a frank and perceptive insight into an all too familiar journey
Three and a half years ago, my wife and I moved to Rosebank and became proud owners of a property that included about two hectares of mainly regrowth rainforest adjacent to Coopers Creek. It all looked wonderful and we enthusiastically embarked on a plan to get a grant to extend the forest into an adjacent paddock.
Mark Dumphy from Firewheel Nurseries visited to advise and we were surprised when he told us “we had a lot of work here”. He was referring not to the new planting, but to removal of small-leaved privet that dominated the understorey.
Not deterred, we put in for a grant to cover the new plantings and some existing rainforest clean up. We were also advised to get assistance with the application presentation and not to provide too much of a breakdown of the costs. So we removed this from our draft and sent it off. Our application failed with the main reason given being lack of financial details! Things do turn out for the best as we soon discovered that we had more than enough on our plate regenerating what was already there without adding to our workload.
Knowing where to begin on restoration was a dilemma. Mark’s simple advice was to start with what you regularly see, on the basis that you will be encouraged if you see the results of your labours. So we started working along the forest edge adjacent to the house. At least weed identification was not a problem as the only ability needed at this stage was to identify privet. According to size we sprayed, cut and painted privet, or for the larger trees, injected. This was quite good fun, but progress was very slow and although things did speed up with practice, I am still unsure of the best approach if, perish the thought, we were to start again.
As we moved further from the house, we widened our knowledge of weed species. Lantana, black-eyed Susan, freckleface, broad-leaved privet, mistweed, moth vine, passion fruit etc. – all could be controlled with varying degrees of ease. Most surprising was about half an acre carpeted with a Philodendron species – maybe resulting from someone’s discarded pot plant. This has proved challenging as it resists repeated spraying, at least using glyphosate, metsulfuron-methyl (see Metsulfuron-methyl, next page) and Pulse. Where it had climbed high into trees, every single aerial root in every tree crevice had to be removed and even then it could grow in the bowl of a tree and send roots down. It is still returning today though in much diminished form.
The real problem, far surpassing all other weeds, has been madeira vine, which existed in about a hectare of the rainforest. An article in a future newsletter will cover the madeira vine experience.
It took about two years to make a first pass through all of the forested area, much of which was impenetrable, and with some areas almost inaccessible, being rocky and steep. To give some picture of the work you must imagine me, old enough to know better, perched on a 50 degree slope, hanging on to nearby vegetation, trying to separate arrow-head vine, a threatened species to be cosseted, from the competing madeira vine, while trying to avoid the incredibly sharp cockspur prickles. Or, hacking through vines various, to give the overwhelmed trees some chance of survival.
The work then became controlling weed regrowth. Where the canopy was already established this was easy but there were significant areas of open terrain especially where lantana or large privets had dominated. Of the 300 metres or so of creek frontage, about half was a flat open area, about 30 metres wide, which was weed heaven, where it was difficult to know what to do (Picture 1). If I adopted a scorched earth approach and thoroughly sprayed, then this would not only encourage erosion but require an enormous commitment to tree replanting and more subsequent maintenance than could be managed. It was also clear that any efforts would be washed away in the first storm, when the creek can become 40 metres wide and 5 metres deep.
We were then fortunate to get a grant for riparian regeneration which enabled some replanting to take place. We replanted only at a high level above the creek, the idea being to spread the existing canopy nearer to the creek. Weed control is then limited to a metre or so around each tree.
I have not mentioned the wallabies, one in particular being quite friendly (Picture 2) and very partial to newly planted nursery stock. We have had to supplement the original tree protection by cutting up rolls of wire netting and protecting each tree. Wallaby attack is another reason why planting is difficult at lower levels where any protection will get washed away.
Surprisingly, and despite encouragement by the project manager, some of the professional help that came with the grant was reluctant to attempt long-stem planting (see Long-stem Planting, this page), but once it was found how easy it was to plant with an auger rather than swing a pickaxe they were converted! It is too early yet to judge the results.
Our approach for the lower areas nearer to the creek, as it has developed, has been to spray the whole area, as near as decent to the creek with just Metsulfuron-methyl and Pulse, thus leaving or effectively encouraging the mainly exotic grasses. It seemed to make sense to bring the weeds back to just grass, and get rid of the likes of castor oil plant, tobacco bush, tradescantia and billy goat weed. At some point, the intention is to try to win over the grassed area to lomandra (Picture 3) but this is a bridge too far at the moment; initial attempts have been overwhelmed by the existing rampant grasses, not to mention repeated floods. The natural creek-side understorey plant in less disturbed parts of the creek bank is mainly thorny pea, and it is an aspiration to get it to spread further into the disturbed areas.
As things stand we have the forest almost under control. The open areas are gradually filling in, with native seedlings appearing, and the adjacent canopy closing over to reduce light levels; but weed control is a problem without having done a dense replanting in all open areas.
In the three years the total effort taken has been about 2,000 hours. This may seem a lot for two hectares. Without the madeira vine it might have been, say 1,200 hours; on easier terrain it might have further reduced to 800 hours; with more experience and if I had the energy of youth it might have reduced to 600 hours. With less care of native species this might have been reduced further. Weed control has also been particularly onerous having barely had a dry period in the three years. Of course there is no management overhead or travel time to supplement numbers and work can be more effective with frequent short work episodes to keep on top of weeds. Currently maintenance takes about five hours per week.
What are the lessons learned? Most important is to realise what a potentially dangerous activity bush regeneration is, especially on a steep, rocky and unfamiliar terrain. I am struck by the variety of hazards and my lack of any significant injury is partly just down to luck. If one does have even a minor incident it is worth stopping and reflecting on why it occurred, whether it could have been serious and how the circumstance can be avoided in the future. Tripping, eye damage and ticks might be my top three risks, but they could be supplemented with anything from drowning to snakebite. Having a means of communication if working on one’s own is essential. I carried a two-way radio, given there was no mobile phone coverage. Safe Work Methods statements for Bush Regeneration can be found on the Internet and are worth reading.
In the same vein, working comfort is important. In my case this means carrying the minimum necessary equipment up and down slopes – quality lightweight loppers and a good small handsaw are a necessary investment. I could not get on with a poison pot and a brush as being too cumbersome and instead used a small plastic dripper bottle. I stuck brightly coloured sticky tape on all equipment but even then I still lost a few things. Especially in difficult terrain make sure that you create satisfactory access and do not put up with walking on dead branches and the like. Always carry some coloured tape with you to mark any issues that you need to return to, and remove it afterwards.
I should have been less reluctant to cut back the native vines, mainly cockspur and water vine that were not only slowing the development of the canopy but also obstructing maintenance. At worst, a lone tree 25 metres tall supported 20 metres worth of thick vine (see Picture 4). I did not remove native vines where the canopy was well developed, but in open areas there was no alternative to reducing them. In fact water vine regrowth provided quite a useful temporary ground cover.
On easier ground, I wonder if it would have been more effective to take a brush cutter to the privet up to a few metres high, accepting the extra collateral damage to natives, and then spray the regrowth. Successive sprayings will be necessary anyway, so why not just try to remove the younger privet as quickly as possible and rely on fresh native regrowth? I am struck by the paradox that in the time it takes to pull up an individual privet seedling, the rest of the privet population may have grown by more than the size of privet I am pulling up. It is nevertheless the best approach, because if you take out the biggest privets first, the smaller privets quickly become a bigger problem. However, it may be worth addressing the biggest privet first if you will avoid another season’s worth of seeds. I wonder if it is better to take a chainsaw to the larger privets, also cutting up the trunks, rather than injecting, so that you can avoid the long slippery fallen stems later. Privet seedlings left on the ground after pulling up seemed less likely to regrow that a neatly cut metre long privet stem. I did try scrape and paint on privet but found this less successful with a tendency for partial recovery after a couple of years.
One piece of advice that leaves me puzzled is “that tobacco bushes can be left to provide an initial canopy – they will eventually die back”. The only thing I achieved was a tobacco bush forest together with seed bank, which inhibited natural native regrowth. More easily said than done is never to let an area regress having got it more or less under control.
Although I kept a photographic record I found this difficult. Initially I innocently misunderstood the concept, thinking that the main objective was to compare the weed-infested forest as the starting point, with the forest minus its weeds. This is very difficult as photographing densely growing privet gives a hopeless result, and a photograph after the privet is killed just looks more dismal than the starting point. I hope, with regrowth now occurring, that the record will get more interesting.
A concern is that by cleaning up the rainforest, local bird life may not agree that a more attractive environment is being created. Non-rainforest species, such as wrens and honeyeaters, are quite happy with the lantana etc as it is. Yellow-tailed black cockatoo seemed to love tearing into the privet stems to get to the grubs in the sapwood. Even rainforest species may be deterred by the disturbance and general reduction in ground cover. I suspect that a spectacled monarch nest became exposed during the clearance, and then got raided.
At least we still see or hear several rainforest specialists: figbird, pacific baza, logrunner, rufous fantail, little shrike thrush, large-billed scrubwren, regent bowerbird, noisy pitta, brown cuckoo-dove, wonga pigeon, emerald dove and rose-crowned fruit dove with a single visitation by a wompoo fruit dove. The white-headed pigeons and topknot pigeons seem more attracted by the camphor laurel.
How could I not mention the half hectare or so of camphor laurel yet to be addressed? That is another project.
Most important is to enjoy the experience and privilege of being in such a precious environment.