Fire Effects on Seed Release and the Emergence and Establishment of Seedlings in Banksia evicifolia L.f.

Fire intensity and seasonality affected the release of seed in Banksia ericijolia L.f, and the post-fire emergence of seedlings. Mean maximum temperatures recorded in a heathland burn in May 1977 at heights of O4,2 and 3 m were about 400,275 and 175 OC respectively. Variability in maximum temperature was dependent on the age and position of B. ericijolia stands. Release of seed held on B. ericijolia bushes increased significantly after fire. The proportion of seed released on unburnt controls stayed constant. Seeds were released earlier and quicker fromcones exposed to high fire temperature maxima than from those exposed to low fire temperature maxima. Up to 80 percent of the seed bank was released 95 days after the fire. A greater proportion of the seed bank emerged and establis hed as seedlings 5 months after the fire in May than after a fire the previous February. Seedling emergence and mortality were broadly related to rainfall over this period. The relationship between various fire regimes and abundance in B. ericijolia populations is discussed.