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RE: Eucalypts & Fire

The major danger facing anyone who grows or has numerous Eucalyptus spp.
or for that matter many other Australian natives such as Melaleuca spp.
is the high level of flammable oils in many of these spp.
This is what many of them are harvested for overseas and the coppicing
or base pruning is one way of maintaing  high levels of new shoot growth
at reachable levels.

This low growth height can actually make the tree more of a fire hazard
and once a HOT fire gets into a canopy of  highly flammable oil bearing
trees the effect is highly exposive!
The trees do literally explode!

This possibly explains why the spp. that coppice easily can tolerate
being burnt so badly while those very large trees with the open canopy
won't suffer so badly as their canopy wouldn't carry such an explosive
flame front, they would still burn but slower and with less damage
allowing more regrowth from the existing branches.  When you have a very
very hot fire you can see where the big Euc's are killed outright as
they are cooked in the heat of the fire, of course thosands of seedlings
emerge but it may take 100+ years to reach that forest equivalent prior
to the burn and thats without any of the human or weed pressures
imposed.

Even fire dependant spp. such as many Australian natives never had to
compete against  these pressures.  Pro fire lobby groups really only
present a small side of the story.
I used to own a 232 acre bush block that was burnt twice in two years
once by a bee keeper who forgot to put his  smoker out,  the other by a
lighning strike, or so they thought, a pyromaniac lives next door
though!  
My shed/house and all my gear survived because I have no trees within 30
meters and allow no grass or weeds within 15 meters.  The volunteer
firefighters were impressed with my efforts at keeping the place clean
of litter etc and used the site as a base while fighting the fires
there, "beats drinking dam water" one said glad of my rain water tanks.

The fires killed a lot a really good old bush that hadn't been burnt for
nearly 100 years and exposed a lot of the block to erosion.  I spent a
lot of time building tiny diversion banks three to six inches high out
of rock and branches to trap soil movement after rainfall.  And this is
where all the seedlings germinated next winter in the soil  trapped
behind the banks.  Soil that would have ended up down the hill in  my
neighbours, then his neighbours...

Again this year we have had huge fires out that way, Pingelly &
Brookton, dozens of people were injured and a young girl was killed
trying to save her horse, the horse survived.

Trees are nice &  butt people start fires

Have a fire free summer!

Rod

Rod Randall
Weed Risk Assessment
Weed Science Group, Agriculture Western Australia
Home Page  http://www.agric.wa.gov.au/progserv/plants/weeds/Weedsci.htm

             "I weed..."

>  The trees were kept small and heavily pruned to encourage the
> glaucous young growth which is prized by florists. In this situation I
> don't think it would
> be such a fire hazard. 
> 
>
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