Fire in Australia

[Lesley Cox]

South African Protaceae also need fire or at least smoke to trigger germination. Terry Hatch near Auckland has done a lot of work using a smokehouse such as is used for fish or smaller meat pieces, to research what smoke can be useful for. Some interesting results I believe.

[arillady]

Cohan I went to a talk on Eucalypts by a young guy who has done much work on the different species and has a wonderful collection down south of Adelaide. Eucalypts of South Australia by Dean Nicolle.ISBN 0-646-32743-7. Or contact Dean at 156 Pimpala Road, Morphett Vale South Australia 5162 for a copy as he was self publishing it. Around $20-30 Aust. It was then that I learnt about the different groups that Eucalypts are divided into. Most seem to regenerate from the trunk but then there are others which are killed outright. Some make great rounds like a mushroom - regenerating from the roots.

[cohan]

Cohan I went to a talk on Eucalypts by a young guy who has done much work on the different species and has a wonderful collection down south of Adelaide. Eucalypts of South Australia by Dean Nicolle.ISBN 0-646-32743-7. Or contact Dean at 156 Pimpala Road, Morphett Vale South Australia 5162 for a copy as he was self publishing it. Around $20-30 Aust. It was then that I learnt about the different groups that Eucalypts are divided into. Most seem to regenerate from the trunk but then there are others which are killed outright. Some make great rounds like a mushroom - regenerating from the roots.

a fairy circle of eucalyptus

i recall a south african seed vendor (dont recall which) which sold a pouch or packet of some substance which was used to provide the chemicals that smoke would provide, to seed before sowing..supposed to be very useful for many...

[Paul T]

Cohan,

You can buy "liquid smoke" here as well (I think that is the name), for the purpose of germinating Aussie native seeds that need smoke treatment.

[cohan]

Cohan,

You can buy "liquid smoke" here as well (I think that is the name), for the purpose of germinating Aussie native seeds that need smoke treatment.

neat stuff! i havent heard of any of our natives that need that (doesnt mean they dont exist) i know there are pines that germinate after fire, but i think thats physical--heat to open the cones!

[Lori S.]

Volume 63-2 of the NARGS Rock Garden Quarterly had a very interesting article on smoke treatment to improve (or allow) germination of North American species.  
The author, Michael Young, said that the effectiveness of the treatment was known from South African and Australian species, and he noted the same in comparably fire-prone areas, e.g. Spain, California, and "the intermountain and Great Basin grasslands".  By extension, one would wonder if the same is not likely true for species in the Great Plains, the Rockies (and the boreal forest?)... which is hypothesis put forth in the article.   It concluded by saying that more people needed to do more testing, but that positive results were seen in some species of Argemone, Monardella, Eriogonum, Chaenactis, Festuca, Penstemon, Salvia...

Yes, Liquid Smoke(insert little trademark symbol here  is available here too... for imparting a smokey taste to foods...  but apparently contains enough of the "real thing" to be effective for seed starting.

[Paul T]

Cohan,

Fire is such a big part of our ecosystem that it really has become a necessity for many of our native plants, in many cases to open the cones so that seed can be shed, then the ash is in the soil for them.  Fire clears out the cover so that there is light and less competition, the perfect situarion for seeds to germinate.  That's why they are triggered so heavily by it..... get in quick so that you can take over the available space.

Bear in mind that things like the Eucalypts shed bark in strips which helps fires burn, and they put out volatile oils that mean many of the trees go up like a torch when fire hits them.  Our forests aid the fires, not work against them. 

[cohan]

lori--it certainly wouldnt surprise me--fire is certainly no stranger in NA west;
i would guess parts of california might be especially adapted to that kind of pattern, since brush fires are so typical there..
i havent come across any species in seedlists that seem to germinate only after fires, but maybe its more an enhancement than a necessity... have you encountered any species in those genera resistant to 'normal' germination?

hard to tell up here, with the environment so altered, but the mixed forest here, with lots of aspen and willow, birch etc, is not so flammable as areas with more exclusive conifers; apparently, before european settlement (which, remember is quite recent--in this area, in the 1900's) native groups set fires in this area to extend the prairie grasslands (and therefor bison range) into this naturally forested area... certainly nothing that grows regularly around here could wait for fire to germinate, but there are definitely species that take advantage of sudden clearings, by fire or blow down, and those that benefit from clearing undergrowth, dead grass and leaves etc; our most mature forest type in this area--solid spruce--has a much lower species count than most of the transitionary phases..

[Paul T]

Cohan,

Think that many thigns would eventually germinate without the fire (if the seed survived long enough), but the germination would be sporadic I would think.  The fire treatment breaks the germination inhibitorsapparently, getting the germination process off to a flying start.

[Lori S.]

Cohan, I have failed to germinate a goodly number of species... but I wouldn't necessarily conclude that it was for lack of smoke treatment, LOL!  (I admit I don't have the discipline, or interest, even, to do controlled experiments, which is what would be required to prove that smoke treatment is essential or beneficial.  In Deno's opinion, this seems to include even involve quantifying the giberellin effect in the soil... much more than I have the tools to do.  )
  
The article is only 3 pages and doesn't seem to intend to list all species requiring or benefiting from smoke for germination... It says, "By the early 1990's, botanists working in fire-prone landscapes in South Africa and Australia recognized that smoke improved germination for many species.  The effect also applies to plants from comparable habitats in Spain, California, and the intermountain and Great Basin grasslands of North America.  Frequently, exposure to smoke not only increases the rate or amount of germination, but it is the sole treatment that breaks dormancy in these species."  Unfortunately, it does not list references.  Is it true about the "sole" treatment? I don't know... but no one seemed to jump on it in later issues, so I assume it is accepted.

An aside.... I dunno, I'd find it pretty hard to believe that aboriginal people - ekeing out bare survival in small bands across the northern half of North America, mostly nomadic and outdoors through all seasons; hunting with primitive weapons and gathering plant material (and probably starving, frequently, as well as dehydrated); getting around on foot or with the help of dogs or through the last snippet of time, with a few horses, and living to what, maybe 30 years of age, if lucky?  - had a large enough sphere of vision to worry about the natural succession of grasslands edges and meadows to forest, or were even measurably affected enough by it to change it.  (Was there a reason why plains bison would have been preferred over the wood bison, or the deer or elk or moose that would have inhabited the area in question?  Could those little bands of people and their puny effects - a few more forest fires than would have naturally occurred - have had any influence over the migration patterns of plains bison, really?)  However, I can imagine fire may have been used to drive animals... why not?   But I'd guess that any conscious need to change the landscape (i.e. to sustain resources) would only come with settlement (and that would generally be associated with agriculture - crops or cattle)... but why bother do that when you can just move on?  Before "settlement" came along and wrecked things, such as they were, I mean...  
Anyway, totally off the topic...

Apparently, the conclusions of a group from the Kirstenbosch Botanical Garden in South Africa on the subject were published in The Garden, July, 1995.  Deno talks about and critiques some of the conclusions in his First Supplement to the Second Edition of Seed Germination Theory and Practice, and also comments on the work done at the Agricultural Station at Gosford,  NSW, Australia.  I won't quote it (unless there is a specific interest in it) but it's very interesting reading.

[cohan]

(I admit I don't have the discipline, or interest, even, to do controlled experiments, which is what would be required to prove that smoke treatment is essential or beneficial.  In Deno's opinion, this seems to include even involve quantifying the giberellin effect in the soil... much more than I have the tools to do.  )
  
  Is it true about the "sole" treatment? I don't know... but no one seemed to jump on it in later issues, so I assume it is accepted.

An aside.... I dunno, I'd find it pretty hard to believe that aboriginal people - ...- had a large enough sphere of vision to worry about the natural succession of grasslands edges and meadows to forest, or were even measurably affected enough by it to change it.  

beyond my range, too..seems pretty accepted as important in some SA and Aus species, though the scope of the importance might be questioned when coming from someone selling the 'smoke'...

it would be interesting to see if there are any sources to back up the info about native land management in this area; i think (i say, i think, since wherever i heard it its now a long time ago!)it comes to me from family sources, who moved into this area only in the 1940's, when a lot of this area had still not been cleared by settlers--(in fact, land was still being cleared in my childhood in the 70's; i was happy to see when i came back that that trend had not continued, in fact, there may be more forested land now than when i was young)...
and native groups (who would have lived farther west) still occasionally passed through gathering berries etc..i was told that most of the forest in this area was not much older than the time of the first european settlers (a few decades before my family, but not everywhere), and there were no really old forests around here.. but again, i've never seen any documents on the subject..
certainly, it would not have been a very difficult undertaking--grass fires are not at all uncommon in the areas east and south, and would very easily discourage trees from growing in areas such as this; if you could encourage the massive bison herds, it would be a much easier living than hunting solitary animals in the bush..

a very short search turned up this reference, from the page below:
'There was also deliberate burning by Aboriginal peoples to improve grassland for forage or to drive game.'
http://esask.uregina.ca/entry/grasses_and_grasslands_native.html
i suppose its not a big step from 'improve... forage' to create or maintain forage...
Edit: apparently this native burning was more widespread than i realised see this paragraph from page 3 of the link below:

"..the modification of the American continent by fire at the hands of Asian immigrants [now called
American Indians, Native Americans, or First Nations/People] was the result of repeated,
controlled, surface burns on a cycle of one to three years, broken by occasional holocausts from
escape fires and periodic conflagrations during times of drought. Even under ideal
circumstances, accidents occurred: signal fires escaped and campfires spread, with the result that
valuable range was untimely scorched, buffalo driven away, and villages threatened. Burned
corpses on the prairie were far from rare. So extensive were the cumulative effects of these
modifications that it may be said that the general consequence of the Indian occupation of the
New World was to replace forested land with grassland or savannah, or, where the forest
persisted, to open it up and free it from underbrush. Most of the impenetrable woods encountered
by explorers were in bogs or swamps from which fire was excluded; naturally drained landscape
was nearly everywhere burned. Conversely, almost wherever the European went, forests
followed. The Great American Forest may be more a product of settlement than a victim of it.."

http://www.nps.gov/grko/forteachers/upload/Fire%20on%20Prairie.pdf

sorry to our Aus friends for this diversion which should have gone to a different thread perhaps on NA fires! but very interesting..

[ashley]

South African Protaceae also need fire or at least smoke to trigger germination.

The Kirstenbosch catalogue mentions Restionaceae and Ericaceae too.  My own experience with the former has been that smoke primers raise germination rate from very very low to merely very low

[gote]

In Sweden we have two species of  Geranium  G languniosum and G bohemicum which are very rare but occur after forest fires.
They are supposed to need 40-50°C in order to trigger germination and the seeds can stand 100°C without dying. However it seems that they also will germinate without heat treatment if they are very old since they may appear after soil disturbance.
It seems that they have a growth inhibitor that will evaporate quickly at high temperatures or very slowly at normal temperature – so slowly that they are covered up by debris before they are able to germinate.
A certain percentage of the seeds will germinate with normal “garden” treatment but next to never in the wild.
Considering the number of fires in Australia I would expect some Australians to behave in the same way.
Cheers
Göte
 

[Paul T]

Gote,

I don't know.... I can't think of many Australians that would stand 100'C without dying.  It feels bad enough at 40'C to me, although I'm not that tough and Australian.  

[gote]

Gote,

I don't know.... I can't think of many Australians that would stand 100'C without dying.  It feels bad enough at 40'C to me, although I'm not that tough and Australian.  

You are scattering my illusions Paul 
Where are all those corocdiel hunters gone.
Göte