SEED AGING AND SMOKE - PARTNER CUES IN THE AMELIORATION OF SEED DORMANCY IN SELECTED AUSTRALIAN NATIVE SPECIES

Seed germination of many Australian native plant species has consisten tly proven to be fractious. With the discovery of smoke-mediated germi nation, it is now possible to better understand the heterogeneity in g ermination patterns for a wide range of species both in situ and ex si tu. In the present study, over 180 species were examined as to viabili ty and smoke responsiveness of freshly collected seed. Soil storage an d a number of commonly used seed pre-treatments were employed in combi nation with smoke to examine both longevity in artificially constructe d seed banks, and the role of seed ageing in improved germination. Met hods of smoke application for commercial use were also investigated. V iability decline over 1 year varied between 10% and 80%. Reductions of as little as 15% were found to compromise the ability of a number of species to successfully recruit in consecutive seasons. When fresh see d was used, almost 70% of species tested responded positively to smoke whether applied prior to or after sowing. Variation in success betwee n the two methods confirmed earlier conclusions that substances contai ned in plant-derived smoke may be inhibitory at high concentrations fo r particularly sensitive species. Only 10% of species under investigat ion recorded optimum germination with seed ageing alone but when smoke was applied as a treatment after soil storage, 60% of species respond ed positively. Implications for horticulture, rehabilitation, seed ban k research and habitat management are discussed.