An article in the Australian Life Scientist, Aug/Sept 2004 contains some interesting information about smoke's 'phoenix factor'. This is an edited version.

Smokey water has been used for at least a decade to encourage seeds of some recalcitrant native species to germinate. However the exact identity of the chemicals responsible have been unidentified to date.

Researchers from Perth's Kings Park Botanic Garden, the University of Western Australia, and Murdoch University have recently identified the mystery chemical from a class of molecules called butenolides. Butenolide delivers its wake-up call to dormant native seeds at a concentration of only parts per trillion-equivalent to one teaspoon in three Olympic swimming pools worth of water.

Its not surprising that the breakthrough came from Western Australian researchers, as many of the most spectacular Western Australian plants are extremely difficult to germinate. This includes species prized by the cut flower industry, that have to be harvested from the wild-placing pressure on wild populations.

Butenolide also increases germination rates in some vegetables, including lettuce and celery. The compound dissolves readily in water, although doesn't increase the seeds permeability to water but appears to increase the receptivity of the seed to internal reserves of gibberelic acid.

The WA researchers have shown that, even in species that do not require smoke germination, such as banksias and eucalypts, a dose of butenolide turbocharges seedling growth.

Researchers sprayed unburned native vegetation with the smoke solution and found that species richness doubled, relative to areas sprayed with just water. As butenolide can be synthesized cheaply, and is potent at low concentrations, it is feasible to use it for broad-scale applications.

This could be a tool for spraying plant communities that contain rare and endangered plants to stimulate germination without sacrificing existing vegetation, or where wildfire is suppressed.