Treatment Seeds treated with: Smoke Hormone (Gibberellic acid) Smoke + Hormone dH 2 O Growth Chamber Dark Light cycles: 12 hours light at 25 degrees Celsius 12 hours dark at 7 – 10 degrees C Data Collection Number germinated counted & recorded daily for 40 days Data Analysis Percent germination was calculated Percent germination plotted against time showing germination rate WORKS CITED Brown, N.A.C Promotion of germination of fynbos seeds by plant-derived smoke. Phytol. 123; 575 – 583. Deno, N.C Second Edition to Seed Germination Theory and Practice. Keeley, J., Fotheringham, C Smoke-induced seed germination in California chaparral. Ecology. 79; 2320 – 2336.ACKNOWLEDGEMNETS Professor Marilyn Daly, for all her support and guidance. Dr. Neville Brown, for his suggestions and interest. S&S seed company for contributing to the project. HYPOTHESIS Chaparral species treated with combined smoke and hormone will experience greater germination than with smoke or hormone alone. The Effects of Smoke and Gibberellic Acid on Eight Species of California Chaparral. Kimberly Watson Department of Biological Sciences, York College, Pennsylvania METHODS INTRODUCTION Periodic burning of the cape flora region of South Africa and the southern mountains of California plays a major role in determining the type of plant species found there. The dominant species found are the South African Restionaceae fynbos and the California chaparral. Both are known for their increased diversity and intense recruitment of species immediately following fire (Brown 1993). The exact cause of increased germination after fire is not known, however possible causes include component(s) in smoke and/or gibberellic acid. Smoke-induced germination was first demonstrated for a South African fynbos shrub (Brown 1993). Noting the similar ecology between the South African fynbos and the California chaparral species, researchers demonstrated that smoke is also highly effective in germinating certain species of chaparral (Keeley and Fotheringham 1998). Norman Deno (1993) hypothesizes that smoke does not cause significant germination in North American plant species. Instead, he suggests that gibberellic acid (GA), a naturally occurring growth hormone, may play a more significant role in germination. The experiment evaluated eight native California chaparral species: Chaenactis artemisiifolia, Penstemon centranthifolia, Phacelia minor, Phacelia distans, Romneya coulteri, Salvia apiana, Salvia leucophylla, and Salvia mellifera. The purpose of this investigation is to compare the possible germinating cue(s) of smoke, gibberellic acid, or the combination of the two. RESULTS and DISCUSSION FUTURE STUDIES Filter paper in petri dishes is an artificial environment which may not be conducive to seed germination by some species. Use instead a soil-type mix. Evaluate other species of plants that are classified as difficult germinators. ABSTRACT Periodic burning of the cape flora region of South Africa and the southern mountains of California plays a major role in determining the type of plant species found there. Following fire, South African Restionaceae and California chaparral species experience increased germination. Component(s) in smoke and/or gibberellic acid, a naturally occurring growth hormone, may be responsible. Eight species of California chaparral were selected and treated with smoke, gibberellic acid, gibberellic acid plus smoke, or water as a control. Percent germination was plotted against time allowing for a graphical depiction of germination rate. All eight species showed an increase in percent germination, however the treatment results from the different species varied. Therefore, it is important to determine which specific treatment or combination of treatments increases percent germination and/or rate of germination. All eight species showed an increase in percent germination. The treatment that caused greater germination varied from species to species. Therefore, it is important to determine which specific treatment or combination of treatments increases percent germination and/or rate of germination. CONCLUSION Percent germination of Chaenactis artemisiifolia plotted against time. Smoke plus hormone and smoke alone caused greater germination than either the control or hormone alone. The lower percent germination of hormone and the higher percent germination of smoke suggests that smoke has a greater impact on germination than hormone or the control for C. artemisiifolia. Germination rate is not dramatically effected by any treatment. Percent germination of Penstemon centranthifolia plotted against time. Smoke plus hormone and hormone alone caused greater germination than the smoke alone or the control. The lower percent germination by smoke and the higher percent germination of hormone suggests that the hormone has a greater impact on germination than the smoke for P. centranthifolia. Germination rate is not dramatically effected by any treatment. Percent germination of Phacelia distans plotted against time. Smoke plus hormone caused greater germination than smoke alone, hormone alone, or the control. This suggests that the combination of smoke and hormone effect germination greater than either treatment alone, for P. distans. Germination rate is not dramatically effected by any treatment. Percent germination of Salvia leucophylla plotted against time. Smoke plus hormone and hormone alone caused greater germination than the smoke alone or the control. The lower percent germination by smoke and the higher percent germination by hormone suggests that hormone has a greater impact on germination for S. leucophylla. Early on, germination rate is improved by hormone, however over time it has less of an effect. Germination rate is percent germination over time, therefore hormone caused more seeds to germinate in less time than smoke, smoke plus hormone, or the control.