Flowering of Xanthorrhoea fulva: the Effect of Fire and Clipping

Abstract

Xanthorrhoea fulva (A.Lee) Bedford is a dominant plant of wet heath at Myall Lakes National Park, New South Wales, Australia. As for many other members of the genus, fire is the main stimulus for flowering of X. fulva. The stimulus to flowering provided by fire and by crown removal (clipping) of X. fulva was compared in two different seasons and for two different between-fire intervals. The percentage of X. fulva crowns flowering was greater following: (i) summer disturbance when compared with winter disturbance; (ii) short between-fire intervals (3.75 or 5.25 years) when compared with long between-fire intervals (9.3 or 16.9 years); and (iii) burning when compared with clipping. This demonstrates that the stimulus to floral induction in X. fulva is a combination of a seasonal component and crown removal, a component related to the interval since the last fire, and perhaps some other factor(s) not tested for in this study. This variation in flowering response of X. fulva shows the importance of considering immediate and historic characteristics of fire and other disturbances when management decisions are being made.