Took the trek in to check on the progress of this site recently. Part of our strategy against Wallaby predation, as well as using big guards, had been to plant Mountain Ash among some of the large dead Sycamore Maple that had been fallen at the site. Initially it had seemed that this plan had worked a treat, but we had underestimated the Wallabies and last time I visited the site (6 months ago) the pesky Macropods had pretty much munched all of the carefully placed plants; all but confirming that our conventional method of using big wire mesh tree guards is the only way to beat these beasts.
Even species that were meant to be Wallabies least preferred food such as Olearia lirata (Snowy Daisy-bush) were being heavily chewed.
On this visit things were actually looking a little better and it seemed that there had been some recovery of planted tubestock; although the ones not properly guarded were not much bigger than when they were planted over 18 months ago.
The Sycamore Maple which had once completely covered the 2ha site is also not giving up without a fight. A clamber around the site revealed many seedlings emerging and we as a group will focus on removing them before they become large feral trees. On the plus side there is mass natural regeneration of native understorey occurring with an impressive diversity of species, including plenty of Wattles; that have germinated without the aid of fire. The Maple logs that we left in-situ have been a massive bonus because the micro-climate they created has been perfect for fern regeneration, which is happening all over the site. The logs are breaking down quickly now with a variety of Fungi helping the process. We will have another planting day later in the year on this site (using the big Wallaby guards) so keep a look out for it if you are keen to lend a hand.
Overall view of site, showing the mass regeneration of shrubby understorey.
Hiding among the undergrowth a planted Mountain Asf
Snowy Daisy-bush showing the impact of Wallaby grazing.
New Sycamore Maple Seedling emerging.
Rainbow Fungus – Trametes versicolor aiding the decay of the Maple logs.
Logs left on the site aiding fern regeneration
Another log microhabitat providing a great site for fern regeneration.
Prickly Coprosma full of red berries
Lots of Kangaroo Apple with ripe fruit at the site.
Naturally Regenerated Tree Lomatia
Pine Tree that should have been dead by now.
No shortage of Sycamore Maple on site to be found and exterminated.
Last Saturday we held a working bee, weeding at a site (which we do annually) where an invasion of Sycamore Maple seedlings entered the Park from a surrounding property. Initially we were pulling out hundreds of new seedling and now the ongoing effort to remove newly detected seedlings is working well. Like last year there was not a lot of Maple to remove and a lot of the time was spent moving through the site to ensure that the area was clean of weeds, (although we did not get cross to the other side of the gully where there are some more Maples growing). The main area where Maple was found was an open disturbed area that also has a very bad Tutsan infestation.
It was interesting to discover that much of the Tustsan in the area was covered by rust with some foliage looking quite heavily impacted. We didn’t notice the rust last year but when I looked back at some photos I took then, I did see that some Tutsan leaves had tell tale rust spots present. Tutsan Rust (Melampsora hypericorum) is a fungus that was found to be very successful in the Otway Ranges in the 1990’s where it had a significant impact on reducing the cover of this shade tolerant invasive weed.
Our site (or somewhere in a close vicinity) had Tutsan Rust artificially introduced a couple of years back and after some follow up inspections It was thought that it had not taken. After a bit of research I found a document that suggested that Tutsan Rust was already present at Tarra Bulga, A report from 1999 describes rust taken from Tarra Bulga (as well as some from the Morwell River area) being used as part of research project. The Tarra Bulga rust was found to impact the plants in the trial to an intermediate level (i.e. OK but not great). Whether or not the rust is from the attempted introduction a couple of years ago (of which I assume was a more virulent strain) or whether it is the same rust that has been around for longer, can probably not be known without complex Laboratory analysis. But we will continue to monitor the site with interest given the threat that Tutsan presents to the park.
As well as the Maple and Tutsan there were new Blackberry seedlings that we carefully hand pulled as well as a few new outbreaks of English Ivy which we need to remain vigilant for. There were some larger clumps of Blackberry that will need to be sprayed.
Recently trekked in to monitor progress I had been putting it off until the heat wave had passed. It was four and half months since I had last seen the site so I was anxious to see how things were progressing. First impressions where that there has been a lot of regrowth of under-storey the Snowy daisy-bush (Olearia lirata) had really taken off, and it was even harder to move around the site and to spot the Mountain Ash we had planted. With careful searching the good news was that the planted trees were still there and looking healthy and mostly untouched by Wallabies although I was expecting a bit more growth over summer.
The other concern I had was how much regeneration there had been of the Sycamore Maple trees that had dominated this site until they were cut down cleared several years ago. When I had visited in October there were hundreds of new seedlings that had popped up since our planting day in August. I was happy to see that in the more open areas there were few if any Maples (I think the hot summer may have killed them off) it was noticeable however that some of the large stumps had varying amounts of re-shooting from the base that needs to be dealt with.
Hopefully they won’t be a huge threat to the ecology of Tarra-Bulga National Park but it was interesting to spot this crop of potatoes that seem to have become naturalised in a small patch in the park on the roadside along the Bulga Park Rd.
When cyclists from the Great Victorian Bike Ride “ascend” on Tarra Bulga next week they will notice along with the many native plants in flower some attractive looking flowering plants that are in fact not so desirable. One of the most obvious they will see is Creeping Buttercup – (Ranunculus repens). Although there are native Buttercup species this one comes from the Northern hemisphere. As can be seen by the sea of yellow along the roadsides at this time of the year, it has been well established for a long time and has also penetrate to some moist areas deeper in the park resulting in the displacement of native species.
Another weed that is threatening to take over and become more of a pest is Myosotis sylvatica or Wood forget-me-not. There are also native relatives of this plant in existence, but this species is native to Europe and has been introduced to Tarra Bulga from garden escapes. It is popping up all over the roadsides and is threatening to penetrate deeper into the park. Park staff and volunteers are vigilant in trying to remove seedlings whenever they are encountered but the task seems to be getting more difficult.
Made the trek out to the re-vegetation site for the first time since the planting was done which was a bit over two months ago.
From looking around the site there was both good and bad news. First the good, there was virtually no sign of any Wallabies managing to get to chew any of the new seedlings, despite the fact I heard one hopping away when I reached the site. There was good fresh new growth on all the seedlings that I found, hopefully when they become more conspicuous as they get taller the wallabies will still find them too difficult to reach. The bad news is that after seeing very, few new seedlings of Sycamore Maple
The Friends of Tarra Bulga planting day last Saturday was a great event, which will hopefully result in the return of some towering wet forest in years to come. It will also greatly assist efforts to prevent the re-infestation of Sycamore Maple trees into this area of the National Park.
Volunteers managed to plant 600 Mountain Ash (Eucalyptus regnans) species across the site, which was no mean feat given that each plant needed to be carefully placed in a position where they will be guarded from browsing by hungry Swamp Wallabies. This involved scrambling over steep areas thick with fallen branches, while trying to avoid human hazards such as stinging nettles and leeches. While this may sound arduous there were no complaints from the willing and enthusiastic volunteers happy to be out making a difference to the park and enjoying the scenic (but muddy in spots) walk into this secluded planting site.
The group will now carefully monitor this site over the coming years to check that the newly planted trees are growing successfully and retreat any Sycamore Maple regrowth that sprouts from the treated stumps and pull out any new seedlings that pop up. Funding for this project has been supplied by the Victorian Government’s “Communities for Nature” Program.