To go even further from the original thread:
Certain seeds only need smoke to trigger germination, certain seeds only
need fire and there are some that need both.

I worked in a nursery where this was sometimes confused. Because a plant
responds to smoke doesnt neccessarily mean it will respond to fire (ie
sometimes to stimulate this you use boiling water). Usually fire is used to
crack a hard seed coat so water can be absorbed, while the smoke is used to
stimulate the germination process.

David



Also similar is the need for fire or smoke to trigger some Australian
native seeds out of dormancy, or to open their casing. Bushfires are
part of nature here so as it rages through, the seed will open and
smoke will cause a chemical reaction to bring it out of dormancy,
then it will germinate.

Even still, you can simulate the effect with smoky water.

Note likely since most eucalypt trees have a lignotuber just below the
ground.