The Role of Allelopathy, Heat, and Charred Wood in the Germination of Chaparral Herbs1

Assistant Professor of Biology Whittier College, Whittier, California 90608,USA; and Assistant Professor of Biology, Occidental College, Los Angeles, California 90041 Abstract: The herbaceous flora of the chaparral includes annual and perennial species which differ in their temporal relationship to fire. Germination cues for these herb groups could be expected to reflect these temporal differences. Thirty species of herbs were tested for germination in response to Adenostoma leachate and charred stems, direct heat, and their combinations. For herbs present pre-and post-fire, germination was best under control conditions, or with leachate. Fire following herbs germinated best with a combination of charred stems and low heat. The enhancement effect of burned Adenostoma stems was found to be generalizable to other woody plants and was not a fertilizer effect.