Wet Forest Fires -- a Few Observations

Jeff Howes

In November 2006 my wife and I drove from Thredbo to Talbingo via the Alpine Way and noted that the area still looks devastated after the very large and intensive 2003 fires. The main reason for this is because the tall alpine ash (Eucalyptus delagatensis) forests are killed by intense fire and they only regenerate from seed to form even-aged stands dating from the last major fire in the area. They are one of the relatively few eucalyptus species which are specialist 'seeders'. While occasional fires are essential to their long term survival, they need 20 plus years to set seed, so another fire within that period will totally destroy them.

At present this new growth from seed is only about one to two metres high. Interestingly, while the alpine ash is a Eucalyptus, they do not have epicormic growth i.e. vigorous sprouting clumps of leaves up the trunk and along branches, triggered by the death of the canopy that nearly all the other eucalypts have for their survival.

The alpine ash grow in wet sclerophyll forests (also known as tall open forests) and are at their best in the moist gullies and sheltered slopes of the alpine ranges. In some respects, they are left over from when Australia was cooler and wetter many thousands of years ago. With the earth becoming a lot warmer, it most likely signals that we are coming to the end of the last cooler age. As it becomes hotter, we will most likely see more intense fires at shorter intervals and if this happens then the alpine ash will not grow long enough to set seed and this will give the opportunity for the eucalypt species that naturally grow at lower altitude levels below the alpine ash, to gradually work there way up the now drier slopes.

The sad part of all this is that the return of their pre-burn state of wet forests that were so intensely burnt in January 2003 will not occur in our life time, if at all. However, I recommend a drive through the burnt out areas to observe the regrowth recurring now.

For more information read the very informative National Parks and Wildlife Service (NSW) double sided A4 fact sheet: "Fire in the wet forests of Eastern Australia".

From "Blandfordia', the newsletter of the North Shore Group of the Australian Plants Society, March 2007.

Australian Plants online - 2007
Association of Societies for Growing Australian Plants