Seen Over Your House Today

[perttime]

I'm pretty sure fire bombers must be aiming at places where they hope to prevent the fire from spreading further - or to slow it down. There'd be little point in dumping a little water in the middle of an area where everything is ablaze already.

[NARSES2]

That's what my brain says as well but with no experience of it I just don't know

[pyro-manic]

Accessibility is probably a factor, too. If a fire crew can't get to a location on the ground then aircraft are the only option.

[Captain Canada]

Ya I think it's to slow the fire and redirect it. Must work as they seem to do it a lot !

[NARSES2]

Ya I think it's to slow the fire and redirect it. Must work as they seem to do it a lot !

Ah that makes sense  Get it away from habitation and then wait for nature to take it's course

[Nick]

There was a report on the radio about 3 years back where an Outback farm was saved because the trees around it were not Australian. The owners in the 1920s were English migrants who had planted Oak and Elm trees which resisted the fire due to their natural qualities of soaking up all the water and generally being damp.
The Eucalyptus trees all exploded as their natural oils caught light, making this a rare case of non-indigent species being better for the local environment.

In Los Angeles in about 2002 some homes were protected by having acres of cactus plants in the grounds. These were full of water and restricted the spread of the wildfires.

[rickshaw]

Been a few shots of the fire bombers in Aus on the BBC News. I can never quite work out how effective some of these tactics are ? You look at the size of the fire and then the small amount of water/retardant the bombers can drop and it just doesn't compute in my brain. The cost/benefit analysis is probably an interesting one as well and has probably been done at some time and sealed away for a 100 years or so.

The problem downunder is that there aren't that many large bodies of water which say a flying boat water bomber like a CL-415 could fill from, by scooping water from the surface.  Therefore, you have to land.  Now, big aircraft need bigger airstrips and there aren't that many around, either.  It means they must fly further to get filled and each fill takes longer as well, because of their size.  The small crop dusters OTOH can land basically in any paddock, fill up from a water tanker or even directly from a down pipe (Or what what our UK members would call a stand pipe) and then take off again quickly.  It means more sorties per hour and shorter flight times.   The end result is the same amount of water on the fire but more quickly delivered.

I used to work with the Western Australian Department of Environment which is responsible for fires on government land and as part of that I used to be charge of the department's firewalls.  One day I got asked to open the firewall to allow communications between the department's servers and the new GPS locators onboard the aircraft used to fire fires.  I had a long conversation with the fire officer who had asked for this and that was the gist of what I was told.   It was actually quite fascinating in the end, watching the GIS (Geographic Information System) tracking the aircraft in real time as they fought fires.  'cause the only polled their GPS every few minutes, they'd flit across the map, back and forth over the location of the fire.  Great stuff to have helped with.   

[Captain Canada]

Cool stuff. Not that I'm a fan of fire destroying homes or lands, but I'd love to watch the bombers work.

[kerick]

I'm pretty sure its not a matter of putting the fire out as it is attempting to control the fire. Once an area is ablaze it just has to burn out.
A note about the oak trees saving the farm. Oaks have a much thicker back than many trees and are able to withstand a ground fire. If the fire gets up in the branches its a different story. They also shade out much of the undergrowth, allowing less fuel for a fire. People in the US have finally learned that preventing all forest fires leads to a buildup of fallen branches and other debris on the ground. This provides an large amount of fuel for a fire when it does start and makes it impossible to control. Instead of a small fire that stays on the ground it ends up a huge blaze that gets up into the treetops and kills everything. A controlled burn every few years actually becomes less dangerous than no fire for 20 years and then an inferno.

[rickshaw]

Eucalyptus are funny trees in many ways.  They have evolved to make use of fire as a means of not only propagating their seeds but also as a means of clearing other trees and shrubs out of the forest, so that their seedlings can actually sprout before other plants can recover from the fire.

Because they are non-deciduous they shed not their leaves but their bark.  Now, the bark falls off in long strips and will gather on the ground around the trunk of the tree and dry out, making perfect fuel for a fire so that it spreads quickly if sparked but remains low to the ground initially.  Once that fuel source is expended, if nothing else is available, the fire will usually die out.  Which is what generally occurs in a real pure Eucalyptus forest, where a monoculture exists.

Its the other smaller shrubs and trees which will create a fire large enough to create real bushfires, where the upper branches of the Eucalyptus trees catch.  Once the crowns are burning, the fire will spread from tree to tree rapidly, aided by the oils the trees produce in their leaves, which burns intensely and at high temperatures.   These fires will spread for long distances with embers which burn hot and long, on the winds that the fires produce, so the fire moves with incredible speed.   Burning Eucalyptus forests can create firestorms, with massive updrafts and winds.  Back in 2003 the fires in Canberra created the first recorded fire Tornado.

While many trees will be destroyed, most of them will survive, with just the outer layers scorched.  A week after a bushfire, the Eucalyptus will start to sprout new growth all over them and within a month will be covered in fresh green shoots.  It's quite remarkable to watch.  On the forest floor, the ash will be dissolving, returning much needed nutrients to the soil and new plants will be sprouting from seeds, which required the fire heat to sprout.

Some scientists believe that this was the way in which the Eucalyptus trees basically edged out all other species in Australia before the arrival of man 50,000 years ago.  Fires, started usually by lightning storms created the conditions which allowed them to flourish and so they'd spread and once established they maintained their superiority by being able to survive the subsequent fires better than their competitors.

As the Australian continent started drying out, about 75,000 years ago, the Eucalyptus proved they were better adapted to also survive those conditions as well.  They spread their roots widely, far more than most other trees so they can collect what water that does fall, more effectively.  They turn the edge of their leaves towards the sun, as it progresses across the sky, so that they minimise the surface area which water evaporates from.  In times of drought, they will withdraw sap from their limbs and allow them to die and fall (and we're talking about massive tree limbs about 2-3 feet thick at the base - so never park a car under a Eucalyptus tree!).   These were also important adaptions which allowed them to further out compete their competitors in the evolutionary stakes.

[zenrat]

Some scientists believe that the dominance of the eucalypts is due to man using fire to hunt and clear land.  The trees which had not evolved to thrive after fire could not recover quickly enough to compete and so died out.  These were the plants that the herbivorous megafauna  fed on and so they also died out closely followed by the carnivorous megafauna.

[rickshaw]

Some scientists believe that the dominance of the eucalypts is due to man using fire to hunt and clear land.  The trees which had not evolved to thrive after fire could not recover quickly enough to compete and so died out.  These were the plants that the herbivorous megafauna  fed on and so they also died out closely followed by the carnivorous megafauna.

Only problem with that theory is that the Eucalypts were already dominant in Australia before the arrival of humans.   Natural lightning started bushfires were just as prominent.  While I don't hold with Flannery's "Future Eaters" theories about human extermination of the Megafauna, firestick farming was only introduced after the arrival of the main human groups about 50,000 years ago.  What most probably killed the Megafauna was the drying out of the continent after the last ice age, as it drifted north into the drier doldrums. 

[Old Wombat]

Humans probably just accelerated the process.

[rickshaw]

Humans probably just accelerated the process.

The problem with the predation theory is that there are few, if any remains of megafauna which have been found in Indigenes' Middens or caves.  Plenty of smaller stuff, just very little megafauna, which is IMHO understandable - why kill something the size of a car when it's easier to kill some the size of a dog or cat?

[Captain Canada]

In Canada they also use waterbombers to put out giant tire fires.....

http://www.gettyimages.co.uk/detail/news-photo/water-bomber-battles-the-hagersville-tire-fire-which-burned-news-photo/499291335