Seed release in Banksia: the role of wet‐dry cycles

Abstract

AbstractSeed release in two serotinous and two nonserotinous Banksia species from southwestern Australia increased many fold when burnt cones were subjected to wet‐dry cycles compared with those remaining air‐dry. The response was temperature‐dependent, increasing markedly in treated cones of B. leptophylla as temperature was lowered from 30 to 15°C. This episodic wetting requirement at cool temperatures for prolific seed release implies that, following summer fruit opening, dispersal is delayed until the onset of late autumn/early winter rains when conditions are suitable for germination (optimum at ∼15°C) and recruitment. Seed loss from post‐dispersal predation and exposure to high summer soil temperatures also would be minimized.