Ralph's Walk - November 2006

This is an edited transcript of Ralph Woodford’s presentation as he walked through Rosie Tongmar’s and the Nashes’ remnants at the latest BSRLG field day

As we move under the eucalypt here it is interesting to note how eucalypts’ sparse canopy lets light in, making a dappled shade. This dappled light allows many of our weed species to happily germinate and grow. Eucalypt plantations are great for creating Camphor forests. As you can see, it is not just Camphor though. With a bit of systematic weeding we can encourage the rainforest understorey that is moving in as well – the Guioas, Red Kamalas and Cherries.

From this hill we can get a view of the sites that we have been working in (see picture page 6). This sort of area typifies much of our land on the North Coast. It is a regrowth patch dominated by Camphor Laurel with a Privet understorey, but you can see that underneath those weeds, as is often the case, there were quite a few native trees. If you look above Rose’s fence line you can see the Camphor regrowth forest that this area looked like before we began our work below the fence line and I’m sure that if we removed what looks like solid Camphor up there we’d be amazed to see that perhaps a third of that area has an indigenous canopy.

From 2000 onwards we started to work this area in 4 or 5 blocks. In each block we took out all the weeds that were in that area. As Rose has said, it initially looked like a bomb had hit it. We were criticised by a lot of people in the restoration industry who wouldn’t have a bar of this approach. But come back 5 years later and look at it now; the existing canopy has spread and we have a seed bank that has germinated and grown up to create a canopy in that bare site.

This area here would have been described in the Big Scrub manual (Subtropical Rainforest Restoration produced by the BSRLG) as one that you wouldn’t have tried to regenerate; you would only plant in an area like this because the only plants germinating would be Privet and Camphor. Yes, you do get both those trees regenerating, but their seed has a short viability of only 1 or 2 years in the ground. Once you go past that period there are not many seeds coming up. For sure you get Privet and Camphor seed coming up, brought in by birds, but the seed rain from mother trees are the major part of any seed bank on the forest floor. Once that weed seed rain stops and the seed becomes unviable probably only 3% to 5% come in through bird transportation.

We finished working these areas in 2004. I came back a couple of months ago and we put in 6 days over-spraying all the young Camphors and Privets that had germinated on the forest floor and getting those trees that I had initially missed: I believe that I generally miss between 5% to 8% in my primary work. For the over-spraying the Privet, Mist Flower and Croftonweed we have been using Brushoff and for Camphors we use Roundup, so it is a mixture of both those herbicides.

Rosie has a picture taken in 1983 that shows this area as a grassy slope. Historical photographs are important for they make us appreciate how rapidly things move in the North Coast. From a grassy paddock to a 5 to 10 metre high Camphor-Privet regrowth forest and then converting it back to an indigenous rainforest has all happened in 22 years.

We have also tried to work using the seasons. I don’t like working in the heat of summer and so most of our heavy primary work is done in the winter (ie removal of the understorey). The Camphors are killed in the spring. We then follow up on the emerging seed bank, mainly annual weeds initially, as they very effectively take advantage of the light now reaching the forest floor. Once you have light, moisture and heat the annual weeds begin to germinate. We spray them until their seed bank is diminished, providing a competition-free environment in which the early successional species can germinate. It’s a matter of keeping the weeds at bay until the natives form a canopy. Once that canopy forms light levels are reduced on the forest floor and annual weed germination decreases and the only trees that germinate in that shaded situation are our mature phase species. We have a patch of scrub about 1.5 km away, Emery’s Scrub, so we have a good potential for birds to bring mature phase tree seed into this site and, slowly but surely, build up our diversity.

The most common species germinating on this site are Acacia melanoxylon, Mallotus phillippensis, Guioa semiglauca, Pittosporum undulatum, Commersinia bartramnia and Trema aspera. You can also see a little area of remnant forest; right in front of us you can see the crown of a Red Cedar, full of flower at the moment, and next to that is a big Elaeocarpus kirtonii (Silver Quandong) and above that is a Red Bean, so we do have individual mature phase species on the site and from them the seed will move again. Overall the site was pretty well dominated by Privet and Camphor.

We are now at the bottom of Rosie’s property. This is a very frosty gully that has remained a grassy slope for a long time. We have planted frost resistant species, mainly Acacia melanoxylon; it’s great in wet areas and in frosty sites. It’s probably our hardiest early successional species; it gets up quickly and establishes a canopy over the site. This is a big tree in front of us; sometimes they’re a bit too big and powerful and they need a little manipulation by taking 1 or 2 out here and there or by removing branches. Melanoxylon has got a suckering habit so once you’ve got it you can cut one down and another will come up nearby; in that respect they’re good. Melanoxylon planted on wet sites, like where rocks come to the surface forming springs (ie waterlogged) will die but, on the edges of creeks, where your tree is not sitting in water, Melanoxylon will do very well. Melanoxylon is a favourite of Wallabies so you will have to protect it initially but they seem to reach a threshold where suckers or seedlings start coming up and the Wallabies can’t cope with all of them.

You can see a couple of other species here that are good in frosty sites; Corkwood (Duboisia myoporiodes) and Brown Kurrajong, (Commersonia bartramnia) are both good trees. Corkwood is particularly good, almost as good as Melanoxylon, as they will take temperatures down to -7°C but have less of a tolerance for wet feet than A. melanoxylon. It is a fast growing early successional species, and as you can see this one here is already starting to look quite woody. They produce a lot of leaf in the first 18 months and then, when they get up, they become a much more open tree. In some respects that’s good if you have mature phase species around it, as it lets the light in, allowing those trees to get away, but if you haven’t got those species there then the light will allow weeds to grow.

I like to use the early successional species in a suite. Try to plant as many different early successional species as you can so that you get lots of different forms and shapes that will form a dense canopy. You would say Corkwood has a fairly open canopy; A. melanoxylon a fairly dense canopy; Macaranga has an incredibly dense canopy. You mix all those species together and you start to shade out the forest floor. You also have structure in the architecture of the canopy. You have some trees that will pop out the top, (ie Polyscias) some trees spread out laterally (ie Brown Kurrajong), some trees that are balls (Omolanthus and Macaranga). When all these shapes are combined they produce a lot of niches, like you see in our mature phase forest, which are going to attract different insects, birds and animals. This is what we want to do from day one for it is all those birds, insects and animals that really make the forest work.
As you walk through the property you will not see much Wild Tobacco. I see Wild Tobacco as a very competitive plant and I remove it from the sites that I work. A lot of people will see it as a positive plant and if you haven’t got anything other than Wild Tobacco then I would say “fair enough”. On this site we have a lot of pioneers that will fill that niche and do the job just as well as Wild Tobacco. I look at areas where Wild Tobacco dominates and you don’t get to see too many other species growing underneath; it’s just a solid stand of Wild Tobacco with bare ground underneath. I don’t like Wild Tobacco at all but birds love it.

Here we had a very solid stand of Camphor Laurel. There were very few natives growing in here originally but as you can now see there is a dense growth of those common early colonising species that I have mentioned previously: Red Kamala, Guioa and Pittosporum. There are not very many gaps in there now; I don’t mind gaps as they give an opportunity for other species to move in. If we had come in here and had only taken out scattered Camphors and left others, then the trees that we had left would still be taking up most of the nutrients and moisture from this site; they wouldn’t allow that competition-free area that allowed these seedlings to get up and grow. It is only 3.5 years since this was bare soil with Camphor Laurel canopy.

How do I kill Camphors? I have a little generator, an electric drill and a sheep drenching kit on my back. I use a 5/8 inch wood auger bit to drill here and here, around the base of the tree following the cambium layer. I fill the hole with a 2-water to 1-Roundup mix solution.

After the initial poisoning we might have 4 to 5 sprays in the first year, followed by about 2 sprays the next summer and then 1 spraying each year. Rosie concentrates on the woody weeds and doesn’t worry too much about the Farmer’s Friends. I see Farmer’s Friends as a mini forest; they’re no different to a big rainforest, only with a lower canopy. Farmer’s Friends are stopping light from hitting the ground and take up the nutrients and moisture that the seeds need to germinate. So while you have Farmer’s Friends you will have sporadic germination of natives, unlike that of a bare forest floor. If they go to seed you have 7 years of potential weed germination. They can be shaded out. Rainforests expand; they don’t contract, that is unless we interfere, so you have the edge rainforest ecosystem moving out and out. We need to encourage that and take advantage of it. Most of the weed activity is on that edge and if you break that edge you can let the weeds in. It is a common rainforest restoration practice to keep the weeds away from the edge and slowly allow the edge to move out.

Mistflower can tolerate more shade. So should we be spraying the Mistflower and the Farmer’s Friends? I'd spray the Mistflower as it is a perennial and will persist under the rainforest canopy but not necessarily the annuals as they will disappear as the canopy moves out. In this situation we have a canopy that is going to get denser, move out and shade out the weeds. Rosie has had enough spraying the Farmer’s Friends; she probably has other things to get on with in her life. Look at what is regenerating here; they’re long-lived species, Red Kamala and Guioa, that will be hanging around, get denser and moving out. If all we had was short-lived species like Pittosporum, Omalanthus (Bleeding Heart) and Trema (Trema 4 or 5 years before it dies out, Omalanthus about the same) then we know we need longer living species moving into that site or we are going to move backwards towards a weedy site.

You’re always looking at what’s happening on your site. To me, observation is very important. From your observations you can move in the direction that your site is moving you to. Restoration is about you and your site. You have to be involved before you can make decisions. That is why this site is a success because Rose is really involved in her site.

You can see a few other trees here. This is a Cudgerie and just up the track is a Red Cedar. Both of these trees have wind-borne seeds. In my system, if you bare the soil when these trees are fruiting, you will get mass germination. It is good to coordinate the baring of the soil with fruiting of mother trees.

If you look up high on your left you will see the Red Cedar mother tree. What I want to point out here is that the closer you are to a mother tree, the more likely you are of having seedlings come up. If you look in this gap you can see Red Cedar seedlings at about 30 to 50 cm distance so if we had bared all the soil around here at the same time as this tree had fruited we would have the whole area covered in dense seedlings. But this is only a tiny gap that the seedlings have taken over, along with Trema and Duboisia (Corkwood). These seedlings will thin themselves out.

Editor’s note: The battery expired at this point on the recorder and I didn’t begin recording again for some time into the Nash’s afternoon walk. Unfortunately I missed 2 important parts of the field day, a very interesting and detailed discussion on Wallabies and, after lunch at the Nash’s, Ralph’s description of a recently ‘bombed’ site where he has done his latest work (see picture, page 10). Ralph continues his talk as they leave the recently worked area in the Nash’s remnant.

This Pepperberry Tree, Cryptocarya obvata, is typical of what I was saying about Wallabies (see picture, front page): the bark has been eaten, luckily only halfway around. This is a mature phase species that would have come up under the Camphor canopy. But this tree will now appreciate the lack of competition and this summer it will really start to grow.

I’ve been asked how the young rainforest trees survive the full sun when the woody weed competition has been removed. You kill the Camphor and Privet in the spring, before the hot weather, and then they have a couple of months to adjust to the sun. Generally these guys are tough enough. A lot of people say that that is the reason you only take out the Camphors here and there because “you’ve got to give your little trees some protection, they’re really delicate little things”. But on the other hand our Big Scrub manual tells us that we can plant all our mature phase species out into open sunlight – into bare paddocks! We’re contradicting ourselves. These trees are hardy. The only reason that you couldn’t plant rainforest trees into a bare paddock is not because they can’t withstand full sun but because of what is lacking in the soil. We don’t have the micro fauna in those paddocks that we have in these already forested areas. There are a lot of positives in reforesting an area that was already a forest, such as a Camphor forest or Privet forest. We’re starting a long way ahead if we’re working with a Camphor or Privet forest than a bare paddock.

We don’t replant. We don’t need to replant on this site. Planting is the big cost and while we have Wallabies it’s an even bigger cost to the point that it is really hard to justify planting on most sites. I would like to emphasize that you don’t need to plant, even in sites like this which are so heavily impacted with weeds. We still have a seed bank here that will eventually get through and create a forest.

This area was cleaned up 3 years ago and we can see how it has thickened up as opposed to the area that we were last in. There have been some trees planted here, I can see a couple, but the majority have regenerated and they are mostly Pittosporum undulatum. Pittosporum is a strong volunteer in this site. It is probably a bit longer lived than many of our early successional species and provides great perches for the birds to bring in the other seeds. The other seeds should be beginning to be inputted into here; we have a nice clean floor; you can see the Camphors have shed all their lateral branches and this is them all over the floor. We’re building up the organic carbon matter and there is a great litter layer; the sort of forest floor that we’re looking for to help germinate those mature phase seedlings. You can also see that we’re getting lots of ferns back onto the site and lots of little ground covers.

This tree here was poisoned, using an axe, before I came to work here and I’ve been spraying root suckers ever since then. It is a painful exercise to try and kill trees after they have been half-killed. It is quite difficult to get a good kill using a tomahawk, especially on a multi-trunked tree like this. When I drill Camphors I usually work around the tree at a comfortable height; I obviously prefer the drill.

This is the top end of the Ballina Council reserve Houlahan’s Creek Reserve. It’s 10 hectares. I’m not sure of the status of the rainforest trees are in there but in this top end we have a good mix of species. There are some good trees in there but lots of weeds. There’s Cryptocarya obvata, Cudgerie and Ficus fraseri. Also you can see quite a lot of big Brown Kurrajongs, the biggest Brown Kurrajongs that I’ve seen around.

On the bank above us is Steve and Sherri’s remnant. You can see lots of mature phase species. It’s quite a good patch with not a lot of Camphors so that it was just a matter of poisoning the odd stems.

Sherri will now take a group through the middle, up the creek, and I’ll take the rest around the perimeter through the Macadamia farm that encloses this patch.

This area was bared like the original area that we entered. There came a mass of Camphor and Privet seedlings which I sprayed out. Now it has a canopy and I only have to selectively spray once or twice a year. Red Bean is a great tree here; lots of Red Bean here and Cudgerie as well. As wind-borne seed trees they throw their seed about 3.5 times their height. Rubis rosafolius, Wild Raspberry, is a great plant; it fills the niche occupied by Lantana. It’s low, prickly; the small birds use it. If you go out to Rocky Creek Dam at the moment all the Rubis will be flat on the ground from the Wallabies hammering the fruit.

When I came here this patch had an edge of 8 to 10 metres of Camphor, Privet and Lantana. The previous workers here came from the school of bush regeneration that said that you don’t disturb the edge. I come from the other school that says open up the edges, clear the weeds, and let it expand.

There’s one of our Swamp Wallabies up ahead, about to retreat into the remnant. You can see a plastic bag in there. I don’t find that plastic tree guards work. They cook your trees in summer. Use mesh or steel ones, but all of those will cost you $7 each and with the tree $10, and that’s even before you get it in the ground.

You can see where Steve and Sherri have laid the fallen Camphor logs across the gully to slow the water (see picture left). They’ve planted some trees here and plugged Black Bean seeds in over the whole area.

Written by transcript

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