For a long time, people have thought that burn-offs, or controlled burning of bushland, would help to prevent bushfires. But some people are now saying that this isn't the answer.


PAUL McCARTHY: In January 1955 South Australia experienced an extreme bushfire. Two people died on what was dubbed "Black Sunday". Flames tore through Marble Hill razing the governor's mansion and nearby bushland. In the decades since there's been a constant push for controlled burn-offs to avoid similar tragedies, but some are now saying the site of that Marble Hill fire is proof that burn-offs aren't always the answer.

KIERAN BREWER (SA INDIGENOUS FLORA): You see the bare ground there and we've got very little elevated fuel loadings here. So, I mean, there is definitely a case here to say that if an area hasn't been burnt for 50 years there's potentially a lesser fire risk at this site than there is in an area that was burnt in the last 10 years.

PAUL McCARTHY: Kieran Brewer has run a vegetation management business in the Mt Lofty Ranges for the past 15 years. He knows the local ecology inside out and accepts fire is a natural part of the environment. But he says prescribed burns are not always what the doctor ordered and, to demonstrate his theory, he took us to different sites to compare the effects of the burn.

KIERAN BREWER: What we're looking at on this side is the mid-storey, the golden wattle, in an area that was burnt about 10 years ago, and you can see that there's a proliferation of the golden wattle as a result of the fire, it's been stimulated by the fire; and on the other side there you can see a contrast of an area that hasn't been burnt for some time that in fact has very little of the golden wattle in it.

PAUL MCCARTHY: So we've actually got a greater fuel load where the burn-off has occurred?

KIERAN BREWER: I believe that's the case in this particular example here, that's for sure.

PAUL McCARTHY: So we've made the situation worse by burning off?

KIERAN BREWER: I think we have, yeah.

PAUL McCARTHY: He next showed us a spot which last saw a fire 30 years ago and the fuel reduction has been taken care of by Mother Nature.

The message is that the fire risk is greatest in the decade after the burn-off because fire can actually encourage an even stronger growth of new fuel and there hasn't been a chance for it to be naturally removed.

KIERAN BREWER: We shouldn't have a belief that if we're burning we're absolutely reducing fire risk by doing so.

PAUL McCARTHY: It's a stance sure to evoke enormous controversy. Many farmers and firefighters believe prescribed burns are essential to stop further fires.

MIKE WOUTERS: Our knowledge is evolving; the research over the last decade is certainly highlighting that fire isn't a black or white issue. It's about what are we trying to achieve, and let's try and use fire in a positive manner for both fuel management as well as biodiversity management.

KIERAN BREWER: We do need fires; we need areas to be burnt and it's inevitable that all areas will be burnt eventually, and I think what we need is a mosaic of burning so we've got some areas that have been burnt and some areas that haven't been.

PAUL McCARTHY: Kieran Brewer admits he doesn't have all the answers but he urges landholders to consider they may be doing more harm than good by blazing away.