Putting Sassafras back together again

Putting Sassafras back together again? A work in progress, like this page.

How do I know what probably used to grow here? First a bit of information and then some detective work.

There have been a few major rainforest classification works undertaken by researchers, the classification system I use is by Alex Floyd, (1990, vol 1, pp. 22, 23). He uses the presence of specific rainforest tree species and also broad categorisation of rainforest types. This results in what are called alliances and suballiances. An important thing to remember about these alliances is that they can grade one into another over short distances, the causes could be soil types, drainage patterns, altitude, fire etc and they can be a little fluid internally too, perhaps caused by some kind of disturbance. Some newer references use quite broad forest definitions however I prefer to use Floyd for the same reason Stockard does (1992, p. 49), "Floyds' complex system of rainforest classification enables rare and unusual associations to be recognised and guides rehabilitation programs towards restoration of the appropriate vegetational alliance." That is it's not about how to rehabiiltate a site but it is really useful in helping to decide what species if any to put back. During April 2014 I became aware that many NSW Scientifc Committee determinations covering rainforests refer to the suballiances Floyd defined, that reinforced my decision of some years ago to use the system.

On the face of it there is quite a choice in the 215 vegetation lists from all the sites for the 57 suballiances on the microfiches at the back of Australian Rainforests in New South Wales volume 2. I picked some target suballiances and compared them to the 215 plus species currently found on Sassafras. The short story is the best fitting suballiances are 3, 7, 12, 14 and 26 (Floyd 1990, vol 2, pp. 24, 43). There may have been more but that is what I can piece together so far.

Part of the complication in piecing the flora back together is that Sassafras was almost certainly cleared of most trees during the 1920s to 50s. Most of what is here is regrowth and we get lots of frost which mitigates against pioneer recolonisation by frost tender species like Dysoxylum fraserianum or Caldcluvia paniculosa (and there were cattle and probably rabbits too). We have both of those species in well forested areas, D. fraserianum is now appearing as a very common seedling or sapling in one gully, the nearest mature specimen is over 100 metres away in another gully, I now call that recolonised gully Rosewood gully they are so prevalent. Of course there are others spread around the place. There are small specimens of Heritiera actinophylla syn.Argyrodendron actinophyllum subsp. actinophyllum here and it does occur elsewhere in Mooral Creek with quite large specimens and it is recorded in the Surveyors notes for the property immediately to the north, recorded as Stavewood. The name Stavewood could be either H. actinophylla or Flindersia schottiana according to Maiden (1975 facsimile edition), but there are no records this far south in BioNET for F. schottiana.

How did I work out the suballiances that fit? That was interesting, when I read Floyd (1990 Vol 2) and just looked at more mature specimens that were occuring I was drawn to suballiances 12, 13 or 14, I was a bit undecided, my biggest issue was the altitude those suballiances occured at, often some 800 metres higher than Sassafras. What changed my mind was getting easy access to the information on the 2 microfiche cards at the back of the book. I now have it in pdf format, the information was a revelation to me. If you own a copy of Australian Rainforests in New South Wales volume 2 you can have a copy of this pdf, contact me.

In the years since I started that project image to text technology has moved on enough to do a good job with training by me, I have started work on reproducing the lists in a fully searchable version but that will take some time. Then the next project is as Alex remarked, to bring the nomenclature up to date, should not be too hard with fully machine readable text and then a number of the locations have been subsumed into parks. Then comes a relational database.

"The total species list of the community is considerably larger than that given above, with many species present only at one or two sites or in low abundance" (various Scientific Committee final determinations, see References below). The microfiches and the pdf reproduction give excellent insight or background to this statement in relation to flora in similar rainforests. I have digressed but there is relevence, perhaps.

On the microfiche, as mentioned throughout the book, are representative sites of all the suballiances, at least 3 sites, but 4 or 5 are more common, for all 57 suballiances. The vegetation listing seems quite complete, trees, shrubs, vines, herbs, ferns and orchids. I was able to compare my best bet target suballiances, 12, 13 and 14 with my existing plant list - from across the entire Refuge, side by side. I created a new table with the extra columns and manually entered those species found in each suballiance. I was a bit perplexed by the result, not a particularly wonderful fit. Then I consulted Figure 9, firstly I tried for lower altitude, I keyed in suballiance 7. A truly pleasant surprise, a really good fit for most of the trees, herbs, shrubs, vines and to a lesser degree ferns (though I have many ferns left still unidentified). Then I tried suballiance 14 again, which the diagram indicates is based on suballiance 1 with increasing Latitude, not quite so good on some of the trees but it did cover some other tree species that are currently predominant on the slopes not listed in suballinance 7, it was also showing some of the otherwise unmentioned herbaceous species and vines. Then there were the elements only explained by applying suballiance 12. It is important to remember the species list I have here is from across many different locations in Sassafras, ridge tops, gully sides, soaks, gully bottoms, north south east and west facing and it is a regenerating flora.

Suballiance 1, the next step down in altitude from 7, was different because a number of the species did not exist this far south however many of the species that do are found here, I compared for interest sake only. Stockard (1992, p. 48) writes are the 2 most common suballiances in the Manning and Hastings valleys are suballiances 10 and 28, Figure 10 from Floyd indicates 28 is unlikely because of the reliance on fire, too many of the species here are not resistant to fire, 10 is characterised as dry mid altitude, it works but so do 7 and 14 and they cover more of the species here. The closest examples of the suballiances to Sassafras

The closest examples of the suballiances to Sassafras

One other point I have recently decided to devote some time to, which had been bothering me for some years is the flood plains in Mooral Creek and in Sassafras. Like many places on the North Coast of NSW we get rampant short lived (usually) floods. There are alluvial flood plains with deep alluvium. Floyd (1990 Vol 2, p. 14), writes that Suballiance 3 "is the major suballiance on the well-drained, fertile, basaltically-enriched alluvial lowland flood plains north from the Manning River." This suballiance explains the presence of a few more species otherwise left out.

The image at right is adapted from SIX maps and shows the locations of the nearest noted suballiance occurrences, with more detailed vegetation listings used for comparison from Coocumbac Island and Wingham Brush NR from Stockard (1992, pp, 50, 59).

Suballiance 26 Floyd, (1990, vol 2, pp. 86, 87) occurs along the upper areas of the creek (we call it Stones Creek) as it crosses back into Sassfras. With one exception Tabernaemontana pandacaqui, the plant species listed in the introductory paragraphs in Volume 2 are all present but the epiphytes are somewhat more frequent in places where host trees and shade are available. The substrate along this part of Stones Creek is the volcanic metamorphic rock hornfels with just a thin layer of soil derived from its' decomposition. The Main Creek Dungog location is just off the bottom of the image.

The lower portions of Stones Creek inside Sassafras have a much deeper layer of sediment, creek flats is currently a good description because the forest has been completely removed over time. My best guess for a regeneration guideline is suballiance 3 due to the deep rich usually damp soils, alluvium. There is a good guide for suballiance 7 in some locations on Sassafras to use around the edges. Suballiance 1 is too geographically distant to consider it as any kind of guide for reintroduction purposes but the cross over in species is interesting. There are enough fragments left around Mooral Creek to give me a reasonable guide as well.

Climate? We get frost in the open here, lots of it. In 2003 we recorded -8 degrees celcius on the back verandah, 2 metres above ground, that and the next morning were quite lethal to lots of Acacia saplings on the creek flats between Brumby Bog and Gravelly bend. Some trees like Alphitonia excelsa and Diploglottis australis were defoliated over 10 metres above ground. I used to use a Silva clino master for measuring tree heights, it mostly works in dense forest, so long as I can see some leaves up top somewhere, now I use a Leica DISTO D8, useful for lots of other purposes from time to time and also quicker than a tape measure in dense forest, where it is truly difficult to pace out distances with any kind of accuracy, how wide is that flood plain, aim, click, record, move on, a cheaper GPS does not work under a thick canopy and aerial imagery is only so good, I do recognise most of the larger trees and shrubs from aerial photos here but not well enough in some places, back to the story. Some 2 or 3 metre saplings like Dendrocnide excelsa and Melicope micrococca were killed back to ground level inside forest by those frosts, they regrew quite quickly the next spring. It is normal now to get at least a few mornings of -3 degrees, last decade it used to be -5 was the norm, before the wet years of 2009-12.

Rainfall? Most sorts except snow. Our average rainfall seems to be around the mid to high 1400mm though the 3 years, Winter to Winter 2012, have averaged 1800mm. Even in below average years we still get lots of light precipitation, dew. It drips copiously from the trees when the conditions are right. Days of drizzle can happen, perhaps you want to see the Sassafras Weather page. In 2013 to date, 18 December, we have had 1668mm but it was an extremely dry spring and summer, with bushfires on the other side of the valley. Thankfully it has begun to rain again but as of early April 2014 we have a deficit of around 400mm for this calendar year.

Geology and soils? Most of what is visible on Sassafras is igneous in nature though we do have small amounts of reprocessed mantle in places and maybe some bits of the Australian plate. Elsewhere in Mooral Creek there are bits of old coral reef, limestone outcrops. Mostly however it was volcanism that has created most the currently visible soils and scree here. This dates from a time when Australia drifted over a hot spot in the earths crust, the most well known example of a remnant of that hot spot is the Tweed Shield erosion caldera, the central bit is Wollumbin, we called it Mt Warning for a few years. You could look at it over head, some years ago I made a panorama from ground level, sort of. Our local version is the Comboyne Shield, Mooral Creek flows of the flank of Mt Killabakh which was a vent on the side of the Comboyne Shield. There a couple of volcanic plugs closer though, Stones Creek, our 3rd order stream, flows off one of them and there is another across the valley. The soils are ferrosols, orange/red coloured soils, with igneous rocks embedded. In places there is a layer of igneous scree, much smaller versions of this.

Judging by the relatively even size of most of the older gum trees on Sassafras that are not old growth (there only a couple of live ones and a dead one), I think it is a fair guess that most of this place was pasture for at least a few years, to be certain I would need to buy the aearial photos from the 1940s or 50s. These older trees are Eucalyptus microcorys, Tallowood, are growing as large spreading trees, the lowest branches are maybe 4 or 5 metres above ground, as if they started growing out in the open with not much around them. The two trees I believe are old growth have their first branches tens of metres above the ground. The newer generation of E. microcorys trees almost exclusively have tall straight trunks, like the Old Growth gum trees, growing up with competition.

There are quite a few Eucalyptus salignus and perhaps some E. grandis. In a pers. comm. on 23 January 2014, Anthony Bean he writes "The fruits are the best way to distinguish E. grandis and E. saligna, but in the summer months at least, bark patterns can also be used. saligna has a buttery yellow bark (occasionally orange), with patches of blue or even brown throughout, while grandis (as you have written) is pure white. They possibly do hybridise, but I have never myself seen a hybrid." PlantNet is the best place to go for some definitive images of the gum nuts. Many of the trees I and others thought were E. grandis are E. saligna, just very straight with no scars or very small scars, the gumnuts and summer bark indicate E. saligna

Are these gum trees rainforest trees, or are they just transient passers by, well that is an interesting question, open to debate. Either way some of the forest on the upper slopes fits neatly in with the description in Remnants of Gondwana: a natural and social history of the Gondwana rainforests of Australia, on page 34, Sclerophyll forests. On Sassafras there are areas on the higher slopes that are developing into or are now like those described for Lophostemon confertus, Eucalyptus grandis, E. saligna and E. microcorys.

Even now, Sassafras seems to be full of weeds to some. You just have to know what you are looking at. Over time, with help from people, web sites and books, and some tertiary education now, I have got better at that. From time to time it helps to go to places that might look like what it used to be, perhaps take a photo, a little like this.

On Sassafras I learned that if I found 2 or 3 species mentioned in an alliance or sub alliance in the pages of the book I could be moderately certain that others were probably there, I haven't found them yet, so keep looking. Sometimes it took a few weeks or months but eventually I did find them. You have to remember this forest is regenerating and I didn't always recognise mature specimens of some trees at times, sometimes it is simply the amount of Privett hiding what is around or above me.

With the help of funding from FNPWS one of the locations I have been clearing is down to the bottom of the Big Gully, generally along a walking track we put through perhaps 6 years ago. I never knew Crytocarya glauscesens was an epiphyte host, it is a good one when it gets to a decent size, below where the Tallowoods stop, about half way down the hill. I also never knew we had the large Ehretia acuminata, Koda, along that track, trunks surrounded by Privett, tops way above the Small Leaf Privett canopy, in with the Large Leaf Privett, at least I knew it was good epiphyte host too. Ephiphytes on Privett are not common at all. I take heart from the times when we had professional bush regenerators and LandCare people come through in the early 2000s, between the 2 quite big Waterhousia floribunda near Stones Brush, no one saw them, the gap is only 30 metres between them so I excuse myself too. At times you really cannot see the forest for the trees, or should that be the other way round?

The difficult bit is you have to know what you are looking for, what it looks like. Using identification keys is okay if you happen to be able to get some leaves, photos are better for id at a distance, where it is obvious what you are looking at, when the leaves are truly distinctive. As an example, I never used to believe we had any Black Booyong. After a couple of years and visits to various places like nurseries and Tapin Tops I got an understanding of what to look for. I then found a specimen, still very much adolescent, growing through Waterhousia floribunda, quite skinny and around 5 to 8 metres tall. I guess after a period of time you become aware that hey, those leaves up there aren't like the others, or anything else I've seen around here, same goes for trunks and especially seedlings and if you're lucky, flowers. The Lauraceae are bit of a challenge though, at times I have had to resort to small circular blazes on the trunks for confirmation of species. We have enough of them, numbers and species, that sometimes I think of Sassafras as the Land of the Lauraceae, the Lauraceae tend to produce lots of fruit, good bird food. The sky was still full of White Headed Pidgeons in Mooral Creek in the late 1920s I'm told by someone who used to eat them when he was a young boy. I digress, again.

References not listed elsewhere;

NSW Scientific Committee (2011) Lowland Rainforest in NSW North Coast and Sydney Basin Bioregion - endangered ecological community listing - Final Determination, Retrieved from http://www.environment.nsw.gov.au/determinations/lowlandrainforest36a.htm

NSW Scientific Committee (2011) Lowland rainforest on floodplain in the NSW North Coast Bioregion - endangered ecological community listing - Final Determination,

Retrieved from http://www.environment.nsw.gov.au/determinations/lowlandrainforestonfloodplain36a.htm

Stockard, J. D. (1992). Floyd’s classification applied to five rainforest sites in the Manning Valley. Wetlands (Australia), 11(2), 46, 59