This article relates to the ongoing debate on Australian Rural & Regional News into Bushfires, Logging, Burns & Forest Management, in particular, into a debate into self-thinning forest understoreys and wildfire risk. The series of articles relating to this particular debate are all extracted on the general debate page. ARR.News will ask each of the participants a question to conclude this debate, at least for the moment.

Roger Underwood, 22 November 2022

Having read the latest comment by Philip Zylstra in the ARR.News journal I was tempted to dismiss it as negligible, and move on. Then I realised that he had denigrated my colleagues, dismissing them as an emotional “lobby group”, and I realised that he must not be allowed to have the last word.

To the extent that we are pushing for Australian governments to adopt a bushfire policy and management practices that minimise bushfire damage to the Australian people, to community assets and the environment, then yes, we are lobbyists. But we do so unemotionally, from the basis of science and experience. We are not driven by ideology, ambition or self-interest, and have nothing personal to gain. We unreservedly condemn the  theories that Professor Zylstra propounds. They offer nothing, absolutely nothing, to the objective of making Australia more bushfire-safe. Indeed, the reverse is the case.

When it comes to bushfire fuels, a subject Dr Zylstra seems not to understand, there are two simple realities. First, in the absence of fire, flammable fuel accumulates in eucalypt forests and does so for many decades; it can reach 50 tonnes per hectare or more.  The second reality is that fires burning in long-unburnt fuels are more intense, are more difficult and costly to control and can do far more damage than fires burning in recently-burned light fuels – even in quite moderate weather conditions. To deny this reality is to deny the experience of every forest firefighter since time began, and the measurements of every fire behaviour scientist in the world.

As I have previously said: if any Australian government was to adopt the sort of bushfire theory advocated by Philip Zylstra, and make this the basis for bushfire policy, it would be an act of criminal irresponsibility. The job of the authorities is to make the firegrounds more bushfire-safe, not to allow them to become more bushfire-dangerous. Obviously, Philip Zylstra is not listening to this message, and I doubt he will ever listen, but luckily the authorities (at least in Western Australia) are listening. They have also unreservedly rejected his theory, and done so on two very sound grounds:  (i) they offer no practical value to bushfire safety; and (ii) they are not based on the scientific record, or on observations and experience in the real bushfire world.

Related stories:

Philip Zylstra’s response #4 – self-thinning forest understoreys and wildfire debate;
Peter Rutherford to Philip Zylstra #2 – self-thinning forest understoreys and wildfire debate;
Jack Bradshaw to Philip Zylstra #2 – self-thinning forest understoreys and wildfire debate;
Philip Zylstra’s response #3 – self-thinning forest understoreys and wildfire risk debate;
Self-thinning forest understoreys and wildfire risk debate – Roger Underwood responds;
Philip Zylstra’s fire research: Adding value or creating risk? : Peter Rutherford;
Philip Zylstra continues the debate – self-thinning forest understoreys and wildfire risk;
Self-thinning forest understoreys and wildfire risk debate – Jack Bradshaw responds to Philip Zylstra;
‘Self thinning forest understoreys reduce wildfire risk, even in a warming climate’: Philip Zylstra responds to Jack Bradshaw;
Comment on ‘Self-thinning forest understoreys reduce wildfire risk, even in a warming climate’: Jack Bradshaw.