Biodiversity publications archive

Country in flames

Proceedings of the 1994 symposium on biodiversity and fire in North Australia - Biodiversity series, Paper no. 3
Deborah Bird Rose (editor)
Biodiversity Unit
Department of the Environment, Sport and Territories and the North Australia Research Unit, The Australian National University, 1995

Discussion 3

Andrew Craig: I've got a question for Dick on his talk. I am intrigued by your comment about the plants and animals being adapted to fire. Do the plants and animals we see in a given area reflect changes over the time that Aboriginal people have been in the area? In other words, to restate that, has there been sufficient time for animals to evolve quite significantly during the period of Aboriginal occupation as opposed to the much longer period during which they have been subjected to natural fire?

Dick Braithwaite: With most of the ecological issues, locally, you have that seasonal drought that Tony alluded to, many of the adaptations are, of course, adaptations to that seasonality as well. So it's very difficult, and perhaps not all that useful, to try to tease those two apart. It's the climate that's the overall determinant over the long term, and fire just very easily and comfortably fits in that context. If you change the fire regime you change the abundance of species but, indeed, the work here on the abundance of animals and plants is made especially difficult by the very great variation we get from year to year irrespective of fire. Most recent work in the savanna is showing very extreme fluctuations in abundance of a sort that we really didn't expect.

Deborah Rose: I want to direct a question or two to you, Peter. You said at the beginning of your talk that you'd seen some really profound differences between North Queensland and the Northern Territory. I wonder if you could just elaborate a bit more on the kinds of differences you've seen, and some of the causes that you believe might be responsible.

Peter Stanton: Some profound differences were brought home to me a few days ago when I watched some burning at Munmarlary. It was being carried out in 24% humidity and 34 degree temperature. Now, I don't think I had experienced, until that day, 24% humidity in the last two years. On Cape York at the moment, even in the driest parts, I doubt if the 3pm humidity would be below 50%, and on much of Cape York and eastern Queensland since April we've had a continual south-easterly air stream with showers and rain, and even where it hasn't been raining there's been cloud. So, the one thing that was very apparent was that the sort of burning conditions we're getting over there in the last few days in August are probably not even achievable in many years in eastern Queensland as late as October or November.

Now, that's the first thing. The south-easterly stream brings different conditions. I don't have an explanation for a lot of other things I saw but the cypress pine one was interesting, and David has referred to that. In Queensland, more often, we have an explosion of cypress pine and it's a pest, even in a very low rainfall belt in the Salvator Rosa National Park, for instance. Major Mitchell dragged horses and carts through there about 1840 and he spoke of the hills in the distance. He called them the Salvator Rosa hills as they reminded him of the works of some particular painter by that name. In that same area today you can't see 30 metres, let alone see the hills several miles away. And when you look from above, look at aerial photos, in particular, you can see what the difference is. The eucalypts that Mitchell saw are probably still there, though all the spaces in between are filled up with cypress pine. Obviously, there's been an immense decrease in fire frequency in that time. Somehow or other the cypress pines got away. I don't know what the full story is, and the only thing that's going to knock them out of the system is some major fire catastrophe.

In north-eastern Queensland the same thing is happening. The cypress is overtopping, in some cases, quite tall, well developed rainforest. But there's a more obvious explanation there that is certainly related to a change in fire regime. The cypress is obviously thriving now, where it didn't 30 or 40 years ago. But there's a whole host of differences in the landscape there as compared to Arnhem Land.

On north-eastern Cape York, you've got another 500 millimetres of rainfall. It's better distributed throughout the year. We can talk about monsoon forest but much of eastern Cape York at the moment is getting drenched with rain, so we don't in reality, have a true monsoon climate. And the landscape is also very much more dissected by drainage lines. You can hardly walk for half an hour, or an hour, without running into a swamp that's pouring water, or another system, such as a rainforest, that would actually stop a fire. You have this matrix of open forest and heath with rainforest and it's all so much broken up that the chances of fire igniting from a distance and carrying all through that system are very limited. That system could only have been maintained by Aboriginal burning where individual landscape units have been lit up over a long period of time. The incredible thing is that when that individual attention has disappeared for as little as twenty or thirty years, on aerial photographic evidence, things like cypress and rainforest have just erupted across the landscape. So, it is a very different landscape. But if we move to western Cape York which is a little bit closer to a uniform lateritic plain with fewer drainage lines, probably a drier climate, I guess you get a little bit closer to the Arnhem Land situation. But even there, there's more evidence for rainforest patches expanding, and for cypress, in some cases, expanding. Cypress doesn't appear to be under threat even in those situations and, once again, the major difference with Arnhem Land is that, in August, you're not going to get 24% humidity. Maybe 60%. Whichever way the breeze or the prevailing wind comes from on Cape York, it's a maritime wind, the north-wester and the south-easter, and so there are certainly very interesting climatic differences. There are some very interesting topographic differences, and also social history, human history differences in that until much more recent time, in Arnhem Land you had continual Aboriginal occupation. In most of eastern Cape York, Aboriginal occupation probably disappeared totally 30, 40, 50 years ago. So, the regions are superficially similar over large areas but when you look at them closely, they are very, very different.

Tony Law (Central Land Council): My question is addressed to Peter Latz. What David is saying about hard decisions and all the rest really does drive a point. In the arid lands context, you were saying, at the end of your talk, Peter, that the best of science and the best of Aboriginal wisdom have to come together. Are you advocating some project or program of action and, if so, what?

Peter Latz: I would very much like to see the Central Land Council and the Conservation Commission work much more closely together. Is that fair enough?

Tony Law: We both know that position. We're talking about 324000 square kilometres of Aboriginal country, not counting pastoral leases and all the rest. There is lot of spinifex and a lot of grass. You've got major access difficulties and all the rest. We're trying to do it in an extremely ad hoc fashion. If we were waiting for politics to sort things out, federation would be past and we'd be into the next century.

Peter Latz: I'm not as pessimistic as you and what you have done in the Tanami desert in the last six months is the best you could do under the circumstances. As I said, the thing about arid Australia is that you have these periods which are not predictable. What makes arid Australia unique, and this is true for the bulk of Australia, is its complete and utter unpredictability. But the beautiful thing about the arid zone is that the plants have lived there for millions of years and they have adapted to this unpredictability.

Freya Dawson (Faculty of Law, Northern Territory University): I've got a question for David. I was very interested in what you were saying about biodiversity not being a list, and that we have to take aesthetic value or other values into account. When you apply that to the Australian situation, you say, we've got to re-engage in the landscape, we've got to make judgements, we've got to make choices. You talked about the savanna being very rich in biodiversity compared to the rainforest and you were saying: 'Obviously, well, you can write a bigger list for the savanna than you can for the rainforest.' My question is: if we're going to re-engage, and it's not on the basis of just a list of biodiversity variables, (ie there are more species here than there), what other values are we going to take into account and how do we actually decide which values to privilege? I got a very strong impression that you had your own sense of value about what was important and what aspects of biodiversity we needed to preserve, but how do we take account of everybody else's ideas on the same thing?

David Bowman: You want the bad news, I guess that biodiversity is going to be shown to be the emperor's new clothes in the sense that when everybody gets down to biodiversity and really starts thinking about it they realise: 'Hey, we've just got a synonym for nature conservation and all the old problems which were connected to nature conservation come back to haunt us.'

The reason why biodiversity got up politically and got onto the agenda of Rio and all the rest of it is because it made these horrendously intractable problems associated with the evolutionary event our species has triggered suddenly seem amenable to rational discourse and very tractable. All you have to do is go and map and plot and count up and average and, you know, arrange networks and it's all going to work nicely for you, we thought. But then actually when you look at the conservation biology literature, people are just beginning to shake their heads and say: 'Well, what about processes? What about changes? What about viable population? What is a whale?' Dumb question! What is a whale? You say 'Oh, a whale is a big thing which lives in the ocean', but whales need at least a mate and then they probably need genetic variability and then they need a habitat and then they need food and then they need population regulation and then they need not to be overhunted and then you sort of wind up realising 'My God! Maybe the ocean is a whale.'

That was my point about biodiversity, and connecting it to fire: biodiversity sounds simple, and fire sounds like an add-on. We'll worry about fire but let's draw up our lists first. And then you realise that really your lists are going to mean nothing unless you have an appreciation of change.

I sound like one of the four riders. I'm bringing really bad news. We are talking about the termination of lineages which have been on the planet for millions of years, probably tens of millions of years and we're terminating them. So, we're talking about some serious decision making.

Freya Dawson: Can I add one point? With the pines that you've been talking about, that sort of change is obviously occurring if they're expanding in some parts of the country and they're becoming largely extinct in other parts of the country, but you're suggesting a process and a re-engagement to bring it back to the way it was? To what extent do we accept that change? And to what extent do we try to actively counteract it, if we accept that the process is going to be continually engaging with us?

Frank van der Sommen (Consultant): Another question for Dave Bowman. It is accepted that the Callitris species on the Australian continent is a permanent relic and there are other examples. So we are looking at remnants of ancient flora. What status do you think they should have today if we are looking at species which are hanging on in an environment which really isn't all that suited to their long-term survival? We are spending a lot of energy in keeping them going. Should we actually institute processes which keep those species going when, in fact, they shouldn't be going at all?

David Bowman: You're in a fantastic restaurant and you've only got a limited amount of money. You've got to make choices about what you're going to eat. The choice with the landscape conservation biodiversity issue is that we've got a limited amount of money, we've got to make some real choices and they're very difficult. There is not a big machine we can feed the data in and it will come out with the answer. Obviously very ancient species are so interesting, they tell us so much about our past and also they're veterans. They've been in the game for a long time. They deserve some respect. You would be heartless to go and root out a fern which is an enormous living fossil, like the ones in Carnarvon Gorge, just because you can do it. Why not respect them? We are going to have to make choices.

My take home message is this: Aborigines created a landscape for which we have been given a very large menu. The menu is shrinking by the day. And so, we've got to decide whether we just let natural processes roll on. We know that life on Earth's going to remain. It's just going to change a lot.

Peter Stanton: Could I present a manager's perspective? I've had it said to me too: 'You're interventionist, just let nature take its course.' To me it seems to be colossal hide and arrogance. We've devastated this continent. We are down to the last 10 or 20% of natural vegetation. It is an island. It is full of feral weeds and animals. And then we sit back smugly and say: 'Let nature take its course. Don't worry about it.'

The context in which we might have said that a couple of hundred years ago is gone. To me as a manager, it's irrelevant what might have happened in the last 8000 years.

I'm told 'Don't worry about rainforest invasion of sclerophyll. It's been going on for the last 8000 years.' I can look and see that in the last 20 or 30 years, in some particular area that I'm responsible for, 80% of the sclerophyll forest has disappeared. The only responsible thing that I can do, as a manager, is to take action to preserve what options remain so that somebody else who's more theoretically inclined, more research inclined, more philosophically inclined, can make better decisions in the future. At least, they will still have options to make decisions on. But unless I take action now in the face of obvious and rapid change, then we won't be arguing about these sort of things in 20 or 30 years time.