SMOKE-INDUCED SEED GERMINATION IN CALIFORNIA CHAPARRAL
JON E. KEELEY AND C. J. FOTHERINGHAM
Ecology, 79(7), 1998, pp. 2320–2336
Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination...
Take a look at the full paper, you might like to look at the methods and presentation of the results given that we will be doing something similar.