***
I got up early one Sunday to drive my older son down to the ferry wharf. We live on the top of a hill, and as we pulled out of the drive-way, the hills to the north were almost hidden in smoke, each ridge more hazed than the one before. Angus suggested that there would probably be more smoke haze before the day was out. The trees on our hilltop were motionless, and so I had to agree with him. We have had several mild and calm days, and the control burners have been out in force, getting ready for the coming summer.
These people have a simple aim: reduce the fuel levels close
to any natural or artificial barrier that might slow the progress of a
fire. Get rid of the dead fuel on the
ground, they say, and you can stop a fire anywhere. Roads and fire trails often travel along
ridges, and these can be used to stop fires dead, provided the available fuel
has been burnt before the fire comes through.
A wildfire feeds on the gases that explode out of the fuel
as the first searing blast leaps forward.
The drier the fuel, and the more finely divided it is, the more gas it
produces in the first moments, and the worse the fire becomes. If the fine, dry, standing fuel is burnt out
before then, the summer wildfires will be starved. That is why we burn the bush each year in
winter and spring.
Aborigines "using fire to hunt kangaroos" by Joseph Lycett: like many early white visitors, Lycett failed to understand the science involved. |
If we burn different patches in different years, we get the
whole of a bush area running through a mosaic of stages. In this way, nearby unburnt areas can first
supply a refuge for the animals, and then later be a reservoir of seeds and
immigrants to repopulate the burnt areas after the fire. These small fires are slow, low in heat, and
give wildlife a chance to escape to neighbouring areas.
Some people say that ‘conservationists’ oppose the
practice. This committed conservationist
does not oppose it, because control burning kills feral plants and weeds,
limits the spread of feral animals, and maintains the biodiversity of an
area. It is far less harmful than a
rampaging wildfire every twenty years.
The opponents are mostly people who let emotion get in the way of good
sense.
The most effective method is to make regular burns along
roads and ridge fire trails, making a site for a fire break in time of
need. Of course, the cowboys who give
4WD off-road vehicles a bad name are forever demanding more roads and better
access into wilderness areas, as though letting hoons in will somehow stop the
fires from happening. We need the fire
trails, we need the fire breaks in moderation, but we don't need any more hoons
in the bush. The fire trails must be
securely locked off, and we have to steer a middle ground between the mad green
disease and organised ruthless perpetual arson.
Control burning must be carried out with care, whether it is
the mosaic form or the roadside form.
Personally, I favour regular roadside burns to eliminate the weeds which
grow there: cars are a major transport method for weed seeds. This has been proven by analysing (would you
believe it?) the sludge tanks of car wash establishments! A good fire every year or two, penetrating
five or ten metres from the road's edge, will see off most weeds, for they are
unused to regular fire, and unable to penetrate beyond the disturbed roadside
verges in any case.
One Sunday afternoon, in spring, 1994, we visited a favourite bush area, one
that was badly burned in then previous January. It
is on a ridge fire trail with a large area of waratahs on its north side, which
should have been blooming by then. Waratahs have
large spectacular red flowering heads, rather like the related Protea, and well worth the walk. As we walked, my son and I played
our usual spring ‘spot the species’ game, while my wife, a better taxonomist,
pointed out all the ones we had missed.
Running across the photo, you can see the fire trail we walked in on. |
be no flowers in 1994, and only a few next year, but 1996 should easily make up for it.
The fire had only run a small distance beyond the waratah
patch: far enough to do significant short-term damage to the patch, but also
far enough to ensure that there will be waratahs there for many years to come,
sprouting from the ashes of their predecessors.
We climbed to the top of the next hill and looked at the
plumes of white smoke rising all around us.
I wondered how many other waratah patches were being licked into shape,
somewhere inside those burning areas.
No comments:
Post a Comment