Role of charred wood, heat-shock, and light in germination of postfire phrygana species from the eastern Mediterranean Basin

Seeds of 22 species collected from recently burned phrygana were tested for their response to fire-type cues of charred wood and heat-shock. All Cistu s species were stimulated by brief heat-shock, as shown in previous studies ; however, none responded to charred wood. Only one of the 22 species was s timulated by charred wood, and only in dark-inhibited seeds, and this respo nse did not occur in the light. The lack of charred-wood-induced germinatio n is in contrast to the substantial proportion of species with this germina tion response reported for mediterranean-type vegetation in California, the Cape region of South Africa, and Western Australia. Phrygana has many spec ies with heat-shock-stimulated germination, primarily in the Fabaceae and C istaceae. This germination cue is widespread in these two families, thus, t he presence of heat-shock-stimulated germination is a result of homologous, rather than covergent, adaptations in mediterranean-climate ecosystems. Ge rmination response to light was not randomly distributed with respect to fi re-type response. Heat-shock-stimulated species were almost uniformly light neutral, in contrast to more opportunistic colonizing species with non-ref ractory seeds, in which half of the species responded positively or negativ ely to light.