Cool Burning for Culture and Ecological Knowledge

All right. Well, I think we've got most of our numbers here now, Tim. I think we might kick things off and and go from there.
And those who arrive a bit later can join in. Thank you all for coming along to our webinar today.
Yeah, sorry. Thank you all for coming on to our webinar today. Very excited to have Tim here today presenting for us all.
Before we get started, I'd just like to do a little bit of housekeeping. As your normal webinars go
If you have any questions, Tim's happy to answer questions as we go. So there is a raise your hand function within Teams.
If you're familiar with it, feel free to either click the raise hand button and ask you a question from there, or alternatively write any questions in the chat and we can filter them through to Tim as we go.
Today's meeting is also being recorded. If you're I just ask, if you're not comfortable being recorded, please just turn off your camera.
But as well as that, anyone who may be in a conference room with multiple peoples in that room, feel free to put through any other attendees who are within the room.
This project here is funded by the Australian Government, the Natural Heritage Trust and delivered by North West Local Land Services, a member of the Commonwealth Regional Delivery Partners panel.
On behalf of Local Land Services, I'd like to give an Acknowledgement of Country. We acknowledge that it stands on Country which always was and always will be Aboriginal land.
We acknowledge that Traditional Custodian of the land and waters, and we show our respect for Elders past, present and emerging.
We are committed to providing places in which Aboriginal people are included socially, culturally and economically through thoughtful and collaborative approaches to our work.
And without further ado, I'd like to introduce Doctor Tim Curran. I know we've got a few familiar faces here in the group and also some new ones, but yeah, I'd love to pass it over to Tim now and let you introduce yourself, Tim, and take it away.
Thanks, Gus. So you'll stop sharing your screen?
Yep.
Thanks.
Can everyone see that? Yep, I've got you there, Tim. Excellent. Great. Thanks everyone.
So as Angus mentioned, this is a project that we've been doing as part of the Australian Government and NSW Government funding.
It's actually a project that is a chapter in Molly Wallace's PhD thesis, and it's work that I've conducted alongside Boyd Wright, Inna Osmolovsky, Jon Sullivan, Zoe Xirocostas, Yvonne Davila and Brad Murray, some of whom are here today.
So I'd also like to acknowledge the Traditional Custodians of the land on which I'm presenting from today, Te Taumutu Rūnanga, from Ngāi Tahu iwi and pay my respects to Elders past, present and emerging.
I'd also like to acknowledge the Gomeroi people on whose land the LLS are on today and extend that respect to all First Nations people.
Tēnā koutou katoa Ko Bindea te maunga Ko Namoi te awa Ko te whenua o Gamilaroi Nō Gunnedah ahau Ko Terry rāua ko Sandra ōku mātua Ko Tim Curran tāku ingoa Tēnā koutou, tēnā koutou, tēnā tātou katoa
So this is my pepeha. I'm a Gunnedah boy or grew up in Gunnedah. I now live across the ditch and I'm speaking to you from Lincoln University in New Zealand, just outside of Christchurch.
Now this is part of a bigger project. So we're going to be talking about the findings of our survey work on the flammability of different species from Northwestern NSW.
But it's part of a, a bigger project within the Cool Burning for Country project that Angus and Angela have been running.
And it's called the Plant BBQ Roadshow. And that aimed to not only do the flammability surveys that we're going to talk about shortly, but a bit of a travelling roadshow taking our plant BBQ, or more correctly Boyd Wright's Plant BBQ, from UNE around to a range of communities and schools throughout north-west NSW.
And that was a lot of fun. I had the great privilege to go back and, and talk to students at my old high school, Gunnedah High School shown here, which was immensely enjoyable.
And they, as you can imagine, when kids get the chance to legitimately burn stuff and measure how flammable it gets, really enjoy the experience as well too.
As Gus has mentioned, this is funded by the Australian Government's Natural Heritage Trust and administered through LLS.
And I just wanted to give a huge thanks too to Angela Baker, Angus McIntosh, Wally Hammond, Luke Raveneau, and George Truman from the North West Local Land Services, who've been really, really helpful throughout this project.
So what are we going to talk about? Well, first of all, we're going to talk about why we would go ahead and burn these plant communities.
So why we're burning box gum grassy woodlands and why we're singeing semi evergreen vine thicket.
I'll then talk you through about how we tested plant flammability, then go through the results that we have, our preliminary results as to which plants burn best and then talk through some of the implications and next steps.
And as was mentioned for those who joined later, if anyone has any questions feel free to ask me as we go through, but there should be time at the end as well.
So I imagine many of us know what grassy white box woodlands or otherwise known these days as box gum woodlands.
Box gum grassy woodlands are. It's pretty much what it says on the tin. These are woodlands that are dominated by various different box species, usually white box and yellow box, sometimes with grey box.
Also with Blakely's red gum. And they have a grassy understory. Now, they occur on productive soils.
And their historical range was, you know, very much down the length and breadth of the Great Dividing Range, both on top of it and sort of spilling over to the western slopes.
And they occur on productive soils. And of course, because they occur on productive soils, that's very, very valuable land for things like agriculture and grazing.
And so they've been extensively cleared and grazed in the past and are now critically endangered.
And, you know, we had these some really neat examples of grassy white box woodlands in a number of different parts of the world.
There's some around Gunnedah, again, where I grew up and as part of the study area.
So this is just a photograph of a white box dominated grassy woodland in Porcupine Reserve or Bindea, the local lookout and reserve.
Now, a key thing to keep in mind is that fire is a really important disturbance in these communities.
And just to illustrate that, I wanna take you through some findings of this really interesting and excellent recent paper.
This is a paper that was just published a few months ago and it looked at plant responses to cultural burning in box gum Woodlands down on the southwest slopes of NSW, so sort of around Wagga Wagga and Young.
And their key finding among many others was that you got. So this is sort of showing the main number of seedlings.
This is grass, native grasses, this is native asparagus, Asparagaceae, or in which case in this case was mostly Lomandra species, so the mat rushes.
And basically what they showed was that there was an increase in the number of seedlings following the burns and it was particularly useful or beneficial if you're in a site that already had a high condition.
So it was in good condition, had more important native species and fewer weeds. So showing that you know the importance of fire in these landscapes.
The other community that we're going to look at today is one that's very dear to my heart and I know to one or two others on this call as well too.
And this is semi-evergreen vine ticket. So this mouthful is the scientific term for a low form of dry rainforest that occurs on productive soils in drier areas.
It's got an extensive range throughout Australia. It actually goes a bit further than this map. This is mainly showing the Brigalow Belt and Nandewar bioregions, but it's quite extensive in QLD.
It's much more complex and a bit more flash. In Queensland. They have bottle trees up there and, and many more species than we do.
But even down here in New South Wales, it's a very interesting type of rainforest.
It again occurs on better soils. And so it's also been extensive cleared and it's now currently endangered.
And again, we get, you know, it extensively in New South Wales. This is I did, I did my PhD thesis on dry rainforests in this area.
And the semi-evergreen vine ticket, which is shown here in the yellow dots. These are all my sample sites.
There's a lot of semi-evergreen vine ticket around Gunnedah, Narrabri, Bellata, Bingara and then up towards the Queensland border.
So it's a, you know, a fairly widespread and quite important piece of our native biodiversity. Vine thicket and fire is a bit more of a tricky situation.
In fact, you would generally hope that you're not getting too much fire in semi-evergreen vine thicket.
And I'll talk more about that in in a second. But because it's a rainforest type, we would expect that many, but not all, species would be likely to be low in flammability.
And that might allow us to identify species for planting in green fire breaks. So green fire breaks are strips of low flammability vegetation that you establish across the landscape to help mitigate fire spread.
And this example here is a nice green flushing Peach Bush Ehretia membranifolia, sort of showing a species that might be quite low in flammability in semi-evergreen vine thicket.
However, like other rainforests, fire is a key threat to semi-evergreen vine thicket.
And this is perhaps best exemplified in a patch of semi-evergreen vine thicket up in far North QLD 40 Mile Scrub National Park.
And what we can see here is an example of what's called the fire weed cycle. And you can see down here in the understory, all of this really dense shrubby brush is lantana, Lantana camara.
And so what's happened here is there's been a bit of a fire. The Lantana's got a hold. The Lantana's then changed the fuel loads in this vine ticket.
And you've just got through this repeated cycle of fire, more invasion, more fire, more invasion.
And you can see these poor old, in this case, a bottle tree and other old vine thicket species.
This used to be a dense canopy of vine ticket, but it's now sort of shifted to this really depauperate, really low conservation value lantana thicket with some emergent vine ticket species.
And more broadly, there's a big issue in conservation around the world with what's called this invasion fire cycle.
And this paper here gives an example of it from the point of view of invasive grasses. So what happens is you get a non-native grass invading an ecosystem.
Sometimes that might be following a disturbance, other times it might just already, you know, be able to get there other by other means.
That grass has greater fine fuel loads, which promotes more intense wildfires, which leads to greater soil heating, which leads to reduced native seedling emergence, which then leads to more non-native grass invasion and just sort of this cycle moving around like this.
And particularly, and the particularly scary thing for this in northern NSW is we have two weed species, two grassy weed species there, coolatai grass and buffel grass, that are both candidates and are known to cause these invasion fire cycles elsewhere in the world.
So it then becomes quite important to understand the fire ecology of these species and how they might fit in with some of these endangered ecological communities that we're really interested in saving.
So that led us to the aims of the project, which was to document the flammability of different species from grassy white box woodlands and semi-evergreen vine thicket in northern NSW with the hope of identifying low flammability species that we could plant for fire mitigation.
So include those in green fire breaks. And our expected outcomes were a better understanding of fire in these systems.
For instance, we might be able to identify some of the key native species that you could use when you're doing burns.
Also get an understanding of the flammability of different weeds. OK, so how do we go about doing this?
Well, this is my colleague Boyd Wright, showing the essence of what we did, which was burning plants on our plant BBQ.
First of all, we collected plants from a range of different sites, mainly focused around Gunnedah and going south a bit of Curlewis.
Essentially we were collecting plants growing mainly in roadsides, the public land, but then also Bindea Reserve here, some indeed in the township of Gunnedah and some also had a newly reserved site out on land that was gifted back following the Shenhua mine. Bindea in Porcupine Reserve we had a range of sites across different ecosystems.
So the semi-evergreen vine thicket up there on Bindea, there's grassy white box woodlands as well too, and a few other different communities.
And so we, we did all this sampling. Once we had done that or once we'd identified we were going to do the sampling, we went identified which species we're going to sample.
So we assessed, you know, some of the common guides for managing box gum woodlands, this one.
And Nick Schultz was really generous with providing some of his plot data. Another one by Rawlings Freudenberger and David Carr.
And then also using John Benson's excellent vegetation classification assessment work to identify what are the most common species in these box gum grassy woodlands in in the northwest.
And then we combine that with, you know, sampling species from adjacent ecosystems.
So the semi-evergreen vine ticket as I mentioned, but also hummock grasslands.
Now we sampled hummock grasslands because hummock grasslands are dominated by the hummock grasses, Triodia, also known as spinifex, which are widely distributed across the Australian continent that cover over 20% of the Australian continent.
And over here or over on the East Coast, they have these scattered little patches of various different species of Triodia.
Now spinifex are widely recognised to be highly flammable species so we included them in our study, even despite the fact that they weren't grassy white box woodland or semi-evergreen vine thicket, because they are likely to give us a sense of what the potential high end of flammability is of species in this landscape.17:30So these species are flammable due to their many fine fuels and their retention of dead material, which Boyd is showing here.
So around Gunnedah, we've got Triodia scariosa porcupine grass here growingon Bindea or Porcupine Reserve.
And in fact, having given that reserve its name. And then we also had this other really interesting plant, which only grows on a single hilltop around Springhurst Hill, is quite morphologically different to the normal Triodia scariosa.
And we're starting to think might actually be something different. But we're there's a team of us working out if whether that's the case.
So once we decided which plants we're going to sample and where we're going to sample, the team, me, Boyd and Molly here, helped by Gus and indeed by others like Angela and George Truman, went around collected plants with secateurs or the pole pruner, put each sample in its own individual plastic bag and then transported those, kept those bags cool, and then transported those bags and stored them in a cool room before we're going to do the burning.
Just prior to the burning, what we did was, and, and this is a standard protocol for shoot some flammability sampling in, in a number of places around the world, was we actually laid the plants out to air dry for 24 hours.
And this is to take off some of the excess surface moisture if there is some. And there was a little bit of rain leading into our second sampling.
So that was quite important and it's just a general procedure that we do.
So once we've done that and we've also sort of taken sub samples so we can estimate the moisture content of each of these samples, we then get to the exciting stuff.
And the exciting stuff is where we burn them on our plant barbecue and it is exactly as it sounds.
So we put them, we put these samples, there's shoots that are 70 centimetres or up to 70 centimetres if they're whole plants, lay them down on this grill which is a, a modified 44 gallon drum, ignite them with this blowtorch for 10 seconds.
And then as Molly's demonstrating here, measure a range of different variables. So we measure the maximum temperature reach with the infrared thermometer.
We use a stopwatch to measure burn time and time to ignition. And we also visually estimate the percentage biomass loss.
And what we found was that. Flammability varied widely. So this is one of the Triodas, the thing that we think might be different.
This is a before shot. This is an after shot showing that pretty much most of the sample has burnt.
But then we also had, so this is, you know, one of the more flammable species, but then we also had species down the other end of the scale.
This is a Ehretia membranifolia or peach bush, again, that one from one of the key vine thicket canopy species that I showed you earlier.
And this is the before and the aftershot. So essentially not burning much at all, if at all, after the blowtorch has been turned off.
So I'm going to show you a few videos here so you can get a sense of what the two extremes look like.
So this first one here is Triodia scariosa from Porcupine Reserve Bindea.
This is porcupine grass. And So what you'll probably hear is a countdown.
Well, in some of the ones you'll hear a countdown of it counting up to 10 to for the blowtorch to be turned off.
So here is Triodia scariosa. Just a quick warning with this one. This might be a little bit loud, so just just at the start, this is Triodia scariosa from Bindea Porcupine Reserve doing what it does best.
So maximum temperature there. Molly 873.873.
We continue painting the flames with the infrared thermometer there and what we're measuring is the maximum temperature reach during that whole time frame.
And as Molly mentioned, that particular burn got up to 873°C. The highest we recorded in any of the testing was 910°C, which was on the other Triodia species.
OK, so let's look at a species down the other end of the spectrum. So this is Myoporum montanum boobialla, or water bush, and you'll see how aptly named it is as water bush.
And so that didn't continue burning after we turned the blowtorch off. So that counts as a non ignition and gets recorded as such.
So that's the same blowtorch which effectively ignited and led to the incineration of that previous example, the porcupine grass not sustaining an ignition once the blowtorch had been turned off on this particular species.
And the final video I want to show you is another one down the low end of the spectrum. This is Portulaca oleracea or purslane, which is a little succulent forb.
So let's watch that one.
And you can see we didn't keep it going in that particular thing. But basically as soon as you turn the blowtorch off, the flame goes out.
All that's happened there is there's been a bit of singing of the leaves. You could argue it's sort of being maybe being cooked in a little bit of a stir like an open heat stir fry type thing.
More on that and I'll come back to that later. OK, so we've done all our burns and we did hundreds of tests on the plant barbecue and we collated our data.
And then the question was is what do we do with it? So one of the very first things we do in this situation is we run what's called a principal components analysis.
And this is a statistical analysis that allows us to reduce the complexity of many different variables.
So four variables in our case show our ignition score, maximum temperature, our biomass burn, now burning time down to the 2 main axes of variation or the 2 main gradients in our data.
So you've got the first PCA axis, PC1 and PC2. And the main thing to get out of this is that basically our four flammability variables were generally correlated with each other and also all with the first axis.
OK, so what that means is that you know, there's, they're all going from left to right.
So these are very low flammable samples. Each, each dot here is a sample and these are the most flammable samples, OK, but all of the flammability is moving from left to right on the on this graph and, and you know across each of these hundreds of points.
And the fact that this first, that all of these flammability variables are correlated with this first axis.
And this first axis explains 80% of the data or 80% of the variation in the data.
What this suggests is, as others have done and we've done in previous research on this around the world, is that you can treat flammability as a single variable in our study.
OK, So you can essentially treat the PC1 scores as overall flammability.
And that's what I'm going to do for most of the remaining explanation of what we found.
So it's nice in this case, basically a higher PC1 score indicates higher flammability.
A lower including negative scores indicates low flammability. The other thing is, is humans love to pigeonhole things.
And this is despite the fact that flammability is actually continuum. So we've really got a continuum of flammability from very low to very high across from left to right across this graph.
But because we like to put things into groups, we can actually do an analysis that clusters together similar samples and similar species.
And that's just a type of cluster analysis. In this case, we use K means clustering to get us, we asked it to give us five different groups.
And so what does that look like with all our data? Now I'm going to take you slowly through a similar a number of slides that look very similar to this.
So I'll just explain this. First of all, this is essentially a an a representation of overall plant flammability.
Now this varied significantly across different species. Here's the PC1 value over here.
Again, basically higher values of that mean higher flammability, low means low flammability.
And you can see our five different groups. So we've got a group here in blue, group in yellow, a group in green, another blue and orange.
Now just to make it easy for, I'm going to flip that around so you can actually read the species names along the along the left hand side here.
So again, it's PC1 values, high flammability to the right.
One other quick thing I just wanted to point out is that we did actually sample among these two St. trees, well, actually three street
trees because we also had Alphitonia excelsa in amongst those, which is also a native species in our vine tickets.
But we sampled cadaghi and silky oak at the request of the team just to get a sense of how flammable some of these really common tree species that were being planted around Gunnedah were.
So I'm just throwing those in there. You can see they're sort of in that moderate to high flammability class.
Won't talk about them anymore now, but happy to chat about them with questions. What I want to do now is sort of take you through each of these different groups.
OK, So what what the analysis did, we said we want five groups and it gave us the, it did the mathematics the statistics to give us the five groups that had species that were most similar to each other in terms of their flammability.
And so you can read these read the species down here on the left-hand side. And so as expected, the Triodia, the hummock grasses, which we thought would be the most flammable species were actually the two most flammable species.
So the most flammable was Triodia scariosa, porcupine grass, the one from Porcupine Reserve from Bindea, which you can see here, very extensive burning also burnt a very long time as well as the possible new species from down around near Curlewis.
But the alarming thing in this, I guess very high flammability class was the presence of buffel grass, one of these key grassy weeds that we're concerned about in terms of what they can do as part of the weed/fires, the fire/weed cycle.
So basically those essentially this is saying that buffel grass is pretty much just as flammable, just as flammable as you know, some of the most flammable plants that we have on native plants in the area.
And that's particularly concerning because of what can happen with buffel grass and other grassy weeds and vine thicket.
So this is a a photograph of a figure from Bill McDonald's PhD thesis on semi-evergreen vine ticket in QLD. Essentially these hills around here, all this darker green vegetation and all these sort of remnants here.
This this is currently vine thicket and this on the slopes used to be vine thicket.
Now this on the slopes is now grassy or essentially grasslands dominated by grassy weeds.
And so what you've had is you've had these recurrent fires. It's it's like a photograph showing the fire weed cycle, the fire weed cycle, the fire grass cycle where you basically get some sort of disturbance on the edge of the vine thickets, the grass invades that makes it more flammable, more likely to burn.
You get a fire that knocks back the rainforest, the vine thicket, and then you get the cycle repeating and repeating and repeating until you gradually start losing your vine thicket up the slopes.
So that's the big concern and sort of further demonstrating with our testing on buffel grass. There's also some concern with this second group.
So this sort of high flammability class, if you will, these are not hard and fast designations. It's just kind of trying to give you some sort of understanding.
So the next most flammable species was coolatai grass. Now I'm sure those of you in the north-west slopes will be very, very familiar with coolatai grass.
This is a big swathe of it actually in a grassy box gum woodland.
This is just north of Baraba from memory when Angela and I were sort of driving up to Bingara.
And as we all know, coolatai grass can just dominate, you know, landscapes, particularly roadsides.
So, and, and again, it's, you know, a highly flammable species, but there's some really interesting stuff in here as well too, you know, and some, you know, better news stories perhaps.
So then we've got things like kangaroo grass, which of course is one of their wonderful natives and, and a, and a key species, a key understory dominant species of these box gum woodlands.
We've also got plains grass, which gets into some of them, but there's also down on the treeless plains.
There's a few other of the different grass species in here as well too, and also white box.
So this sort of group is dominated is essentially coolatai grass, plus the native grasses that you get in in these ecosystems out there and also white box.
Now, I'm not going to spend too much time sort of going down through each of these, these two middle groups, but I just wanted to point out yellow boxes up there.
The two cypress pines are there. There's an interesting vine thicket canopy species, Notelaea microcarpa or native olives are relatively high in flammability.
Then you've got a whole range of different species sort of coming down, starting to get into these, you know, less flammable groupings.
So things like Jasminum lineare native jasmine, wilga, kurrajong, and a few other species of interest, but happy to sort of field any questions about those.
What I did want to do was sort of talk about, first of all, what some of the, the findings regarding kangaroo grass might mean.
So there was a really cool paper published very recently, a sort of what's called a hot topic, so a literature review, a summary of the most important ideas on a particular issue.
And this was pointing out that kangaroo grass is in fact a keystone species for ecological fire management.
And the argument that was being made by made convincingly by these authors was that kangaroo grass is a really important species for burning cool or for doing cool burns because it tends to have enough dry matter on it early enough in the season when there's quite high soil moisture and few of the other species are actually dry enough to burn.
So in other words, kangaroo grass is the main species that that f has dry fuels. And so they, for you can get some cool burns in sort of spring and even possibly I think late winter as well too.
So it's quite an important species to be in there. And this is just sort of partly, you know, sort of showing how all this information might feed into, you know, field scale burns and that sort of thing.
But I want to focus now down on this group right down the bottom down here. This is the, you know, the, the group of species with very low flammability, these ones right down the bottom down here that are depicted but just by a single bar with species that did not ignite once we turn the blowtorch off.
So in the six burns that we did on our on our BBQ, none of these last three species carried a fire.
And that includes this really interesting species, which we'll return to soon, which I showed you in the video.
This is Portulaca oleracea, purslane. Then we had, you know, species, some of their tree and shrub species like boobialla or water bush, again living up to its name, really interestingly, a widespread vine both in vine ticket but also in white box communities.
Gargaloo Parsonsia eucalyptophylla was very low in flammability as well too. And up this end of the, of that group, things like peach bush, which is a key vine ticket canopy species.
Interestingly and importantly, there's a few other vine ticket species in here like things like Rhagodia parabolica, which is now Chenpodium parabolicum.
And yeah, a few Lomandra longifolia, a few of the Abutilons, Solanum and so forth.
So these are some of the species that might be candidates for planting in various parts of the landscape to help mitigate fires.
One of the key things we looked at was that the fact that growth forms varied in their flammability.
So starting here with graminoids and graminoids are just grass-like plants. So it includes grasses and in our case mat rushes.
So the lomandras are also includes sedges. We didn't burn any sedges in in this project and they were the most flammable.
OK, so they were consistently more flammable than the other growth forms. The least flammable group were forbs.
They barely ignited. So forbs are herbaceous plants that are not grasses. And I guess the other thing here was trees were more flammable than shrubs.
And interestingly, and here's what this looks like on a, you know, with all the species identified, you can see that there's this cluster of the grasses or the graminoids are the ones in yellow here.
Basically the top, I think it was about the top 10 or top 8 species were all grass. Most flammable species were all grasses.
There are a few grasses that were a bit less flammable. And then of course, a low flammability graminoid, Lomandra longifolia, or spiky mat rush.
And then the forbs were down here. Trees and shrubs were scattered through and there were just a couple of vines in our data set. And this is what others have found elsewhere around the world.
So work we did here in New Zealand showed that grasses were the most flammable growth form, particularly compared to forbs, which were the least flammable, but also the shrubs and trees.
And some work done by an Honours student that I helped out with in the tropical rainforests in North QLD demonstrated that trees, rainforest trees, were generally more flammable than rainforest shrubs or vines.
One of the things that we plan to do, and we have done just recently, has looked at moisture content and bulk density and how they relate to flammability and explain flammability.
And we'll weave in some of the other traits a bit later as well too.
So what are our next steps? Or apart from adding more traits to it, we're also going to look at phylogeny.
And that's just a fancy name for taxonomic relatedness. So you would have seen in those diagrams that a number of species that were closely related were next to each other in terms of their flammability.
That's something that we found in other work as well too. Basically, if you have similar traits to your most closely related species, then they're probably going to have the same flammability as you.
But what that means is we need to sort of do some certain statistical analyses that allow us to not just test for that, but maybe control the effects that that has on some of the conclusions that we have.
And the other thing that we'd really like to do too, is sort of weave this into a broader project, which we've been working on here in New Zealand for a few years now called Fighting Fire with Food.
And what that might look like in the context of the work that we've done here around Gunnedah is, you know, here's our has our species list.
But what we could do is go through and, you know, information sources like this excellent resource of Michelle's and I saw Michelle's on the call.
Thanks for this, Michelle. It's a great, a great resource. So this just describes a range of.
Plants that were used by Aboriginal people in in the Northwest. It includes things like boobialla and water bush, includes purslane, and includes spiny mat rush.
So Lomandra longifolia. And in the case of these three species, they're actually all down this low flammability end of the spectrum.
So these are species that you might actively plant in your garden or in your landscape to not just provide you with bush food or cultural reconnection, or biodiversity, or all of those wonderful ecosystem services.
But this demonstrates that you could also be planting them to help mitigate fire as well too.
And we haven't, we've only just sort of started tinkering with the list and, and resources like Michelle's.
And you know, this is a very good and hopefully fruitful thing that Molly will continue to do as part of her PhD.
So in conclusion, flammability varied widely as expected.
And as we've found in in other parts of the world and other floras and others have found in other flora as well too, the grasses were most flammable and that included the hummock grasses, the Triodias the spinifexes that we expected to be quite flammable, but also some key weeds.
We found that a range of species have low flammability and so are therefore suitable for green fire breaks.
And that included species from semi- evergreen vine thicket as we expected, but also some of the box gum grassy woodland plants.
And as I've just mentioned, some bush tucker plants as well too. So what this sort of suggests, particularly for the semi-evergreen vine thicket is that there's some potential for targeted restoration of this endangered ecological community based on its potential fire mitigation properties.
I should point out that not all rainforest species and not all semi-evergreen vine thicket species are low in flammability.
We saw that in this data set. We've seen that in every single rainforest flora that anyone's tested around the world here in New Zealand, South Africa, other parts of Australia as well too.
And all of these data can help guide future burns. So if you're out sort of doing a hazard reduction or a cultural burn, this sort of information can help, you know, provide you with some guidance on, you know, the relative flammability of these different species.
It can also be used for fire management, so you can start to understand which parts of the landscape might be more flammable, and why, but also which parts of the landscape might be less flammable and what sort of opportunities that could bring.
Again, for, you know, deploying green fire breaks, perhaps in such a way that you not only improve your fire mitigation, but you also improve biodiversity conservation of these endangered ecological communities and provide bush tucker sources and cultural reconnection.
So you're certainly setting up not just a win-win, but you know win-win-win-win sort of situation with some of these possibilities.
So I'm going to finish up there now with just acknowledging the broader team that's been part of the Plant BBQ roadshow.
So Boyd and Molly, my partners in crime here photographed on our last day of field work up on top of Bindea Porcupine Lookout, Yvonne, Brad, Zoe and Inna at University of Technology Sydney.
And especially acknowledging Inna's great work recently with the analysis and John for being part of the first Plant BBQ roadshow and religiously taking a lot of photographs, including this spinifex here up on Bindea.
So I'll finish there and just throw it open if anyone's got any questions.
Yeah, Yeah. Thanks Tim. That was awesome.
No worries. You kind of alluded to it at the end there just in terms of, you know how your work can fit into fire regimes and going forward.
Yeah, I guess I was just interested in that, you know, we, we look at life cycle history with plants in kind of looking at, you know, what, what fire regime is a good one or, or we should be doing that, I guess.
But just using your, your findings, how, how might that kind of, you know, be further evidence to back life cycle history and that sort of thing.
And, and just following on from that, it'd be really interesting to see, you know, your graphs there with the, the species arranged, you know, maybe by community type just to help.
Yeah, kinda spell that out. Yeah, sure. I, I did think about doing that. But then there's actually a few species that are common to both species, to both community types.
So yes, apologies for I'm not doing that. We'll definitely do that in the report that that follows up from this and happy to field any specific questions about that you have about that.
Your first question is a really interesting one and can be answered with this graph that I, in the royal we, Inna prepared earlier.
So this is those, you know, the same species but showing burning time. And so burn time, one of the, you know, one of the variables that we measured that gets lost a bit in the overall flammability is, you know, essentially the total time of flaming combustion on our barbecue.
And it's really important because it is correlated with fire residence time. So the longer a plant burns, the longer the burn time, the longer a fire is likely to be in that area, you know, residing in that area.
And that's really important for some of the things that you were describing because it's not often the really hot temperatures that kill plants.
It's the how long a plant is exposed to lethal temperatures. And so a lethal temperature doesn't actually have to be that hot.
You know, 60° is enough to start killing cells and it's, you can think about it in the analogy, you can wave your hand very quickly through a really hot Bunsen burner and not feel any effects.
But if you put your hand on a hot plate for a minute, you're going to get real damage to your hand and to the to the cells in your hand.
So this sort of shows again, you know, it's mostly a lot of the grasses, for instance, although some of the eucalypts like, you know, yellow box, in this case white box that have the high burning time.
So they're going to lead to a fire that's going to be resident in an area a bit longer than some of these other ones, at least at this scale that we're looking at.
And I'll come back to that in a second. So that sort of gives some suggestions that some of these, you know, some of these species might cause greater impact on, on the seeds in the soil seed bank on, you know, on other plants and, and tissues in the surrounding landscape as well too.
Of course, the caveat with all of this is, you know, the scale that we're measuring these things at.
So obviously we're measuring for a lot of these things, we're just measuring 70cm long shoots
And so there's a lot more going on in the field with those plants than the 70 centimetre shoot.
Now we're quite confident the 70 centimetre shoot provides a good relative representation of the overall flammability of the whole plant.
But obviously it doesn't capture, you know, the amount of fuel that a tree might have compared to a grass or a shrub or a vine or whatever.
And so these are, you know, these are some extra things that you sort of need to take into account with this.
We're doing some work and we've got some work planned to try and see how well this scales up to field scale fire behaviour.
So the Holy Grail for us and for many around the world is to translate some of these traits, predict how fire might behave in a given area based on the composition of the species in that area and what traits they have.
And then use that to estimate how well they match, match fire based, sorry, field based fire behaviour.
We're a little way off that yet for some of these species. We think it's probably pretty reasonable for grasses and other plants where like, you know, the Portulaca and others, we're actually measuring the whole plant flammability on our BBQ.
But yeah, thanks. Thanks for those questions. Thanks, Tim.
Tim, Nicholas Sharp has just mentioned that he's got some fire history that he's happy to supply, as well as some historic data.
So yeah. Thanks, Nick. Yeah. Please drop me an e-mail, Nick. That would be great to hear. Yeah, sure.
Yeah. Anytime, Tim. So if you want that fire history data specifically around FESM as well, which will give you we go back to 2016 with FESM.
So that's fire extent severity mapping. So that'll give you that real sort of surrogate data set to that intensity of burn as well.
So that kind of heat and the stuff you're looking at. Just a just another point on some of that as well is that the future HRS that we have planned up here in the North West is yeah, I guess, you know, if we're further informed by, you know, avoiding those non-native grasses and perhaps using a different method, right, rather than burning, because all we're doing really is encouraging those invasive species to basically come back even worse and stuff.
So I, I don't think that that's, that's a particular area, you know, we're all about hazard reduction rather than are promoting biodiversity in some cases as well.
And I, I guess that's really important for the RFS to partner with other agencies as well to make sure that we're coming out with those great biodiversity outcomes rather than just reducing hazard, which is, yeah, of course, one aspect, but it's not really doing what we want to do.
We want to sort of introduce those, those breaks in the landscape to, to give us a chance to, you know, really reduce the size of those fires too.
So. Yeah, yeah, that's great. Thanks for that, Nick. Yeah, thanks. Yeah, really appreciate it.
And we'll definitely have a chat later about all of this stuff. The key thing with, you know, burning coolatai grass and buffel grass, you're not going to control them with fire.
That's the thing. Like you're just going to setting yourself up for, you know, more and more fires and possibly worse and worse fires because you're going to potentially going to be spreading the extent of it to the detriment of some of these possibly less flammable nearby native communities.
And, and the other big thing, you know, it's a single, it's a single fuel type. You know, it's, it's a highly flammable at the whole plant level fuel type that is actually, you know, incredibly densely packed as all of you know who, you know, have any experience with these things.
I mean, this is all coolatai grass going in and around here and all the way back. And it's, you know, that it's really, really bad for biodiversity, but also for fire management as well too.
So, yeah, thanks for mentioning. Got a few more questions there in the chat.
Tim, have you got that open in yours? Just opening it now.
This one from Ali Bigg. Oh, yeah, yeah.
Thanks, Ali. Yeah, that's a good one to know that Western Sydney's doing that grassy white box woodland seed work.
And yeah, absolutely you can weave the, the lower flammability forbs in.
I mean, that's starting to become a familiar tale around the world. The forbs, you know, just generally have lower flammability.
I mean, they, you know, they got less fine fuels than grasses, usually less dry fuels like to the usually high moisture content.
The purslane's a classic example of that. It's, you know, it's a succulent, you know, so it's going to have really, really high moisture content, which is one of the main drivers of reducing flammability.
Oh yes, a great question from Ryan. Given the high the biomass on Bindea with highly flammable grass, should we maintain the spinifix as well as the coolatai and buffel. Yes in the short answer is yes, Ryan because it's native to the area.
It's an important component of our biodiversity there. It's a relictual community hanging on from the last Ice Age or, or some other dry cycle similar to that and is actually quite important habitat for a number of different species.
It's known as a keystone species. So it's really, really important in the landscape. What it does mean is that now we know how flammable it is or we've confirmed how flammable it is, is that we can be a bit clever about how it's managed in the landscape, how we manage it with burning there as well too, and what that means for, you know, the adjacent communities.
And the really interesting thing up there on Bindea is that, as happens in other places around the northwest is you've actually got this highly flammable spinifex community growing next to the low flammable semi-evergreen vine thicket.
And they're the two communities that grow up against each other. And yes, this question from Josie.
Thanks for this. Josie. Did you test plants at different growth stages, new growth, seasonal differences?
Great question. No, we didn't, but that's an important next component to any of this sort of work.
So we've been doing this here in New Zealand where we've been testing flammability for 12 or 13 years now.
So we've actually got a list like this that's 550 species long. And now what we're doing is going back through and picking out the species that we feel are important to test to see how they change from season to season.
And of course, we find that some species do change seasonally because moisture content differs, as you pointed out.
So that's a key follow up to do and make sure that you're actually got, you know, looking at all those nuances.
Just quickly answering Rodney's. I think buffel is mainly re sprouting or recovering from fire because of its seeds.
But there might be a buffel grass ecologist on who can tell us that better. Anyone want to type in the chat what the answer to that one is?
I'm pretty sure it's seeds and they may re sprout as well too, but it's mostly going to be seed germination.
I think it certainly leads to the spread and lots of little buffel babies everywhere.
Ryan suggested seed bank. Thanks, Ryan.
Have a lucky last question. Yeah, I think we've got time for just one more.
Thanks, Sally.
Well, Tim, I think if there's no final questions, I think we've, yeah, done well with our time management here.
But yeah, thank you, Tim, very much. It's been an extremely engaging presentation. And thank, thank you to all those who posted their questions.
I'm sure we've got many more as well. But yeah, thank you. It's been great. I'm sure everyone will be watching closely to see some more of your results as they come out, Tim.
So thank you. No worries. Thanks, everyone. Thank you all for coming along.
Yes, Thanks, Gus.