One problem that seems to be overlooked is that Eucalypts are, in general, "fire climax" species. Their seed pods are so tough that it takes a "warm-over by a "moderate" and fast-moving fire to crack them. The passing ground fire in such circumstances is not hot enough to damage mature trees but it simply turns the competing species, i.e. undergrowth, weeds, etc to ash.

The "cooked" seed pods, in their bed of ash, will germinate at the next shower of rain, which is often within days of some of these fires; apparently something to do with all that smoke (particulate matter) aggregating water droplets in the air and so on.

Where it all gets ugly is if there is a LOT of undergrowth and / or litter on the forest floor. Then, the fire's "Time over target" increases as does the temperature of the fire front. Most eucalypts can handle a bit of "cooking, but only up to a point before the outer centimetre or so of the tree does not literally start to boil.That outer layer is where all the traffic of water, nutrients etc travels; destroy it and tree dies. A fast-moving fire can completely envelop a Eucalypts and within days, the tree will be sprouting leaves from all manner of places; epicormic growth. This enables it to continue to photosynthesize and carry on..

Apart from killing mature trees, the other huge problem with high-temperature "floor" fires is that the heat also goes DOWN. This excessive heat penetrating a couple of feet destroys all of the nutrients and "micro-bugs" that process the soil nutrients. This, in turn starves the tree in its survival mode. It also introduces two more problems. Firstly, high-temperature ground fires can often ignite large root systems under the ground and these can smoulder invisibly for days. One of the consequences of that phenomenon is "low-density" ground. What looks like ash-covered ground can be a deadly trap; like walking onto super-heated talcum powder. People have died or been horribly injured in recently burned-out forests, whilst stepping onto the wrong patch of ground. Then it rains, usually briefly, and a huge amount of "cooked" topsoil is simply washed into the waterways, making a huge mess of them and generally unfit for surviving water creatures or even thirsty surviving animals livestock / native animals.

Similar damage happens in the huge North-American Coniferous forest fires.