The Significance of Root Starch in Post-fire Shoot Recovery of the Resprouter Stirlingia latifolia R. Br. (Proteaceae)

Stirlingia latifolia, a common shrub of Banksia woodlands ofSW Australia, is a highly successful resprouter species recoveringfrom fire by multiple sprouting of new shoots from its upperroot stock. in comparison with the congeneric fire-sensitive(obligate seeder) species Stirlingia tenuifolia it exhibitsa low shoot:root dry weight ratio and high concentrations ofstored starch in the cortical tissue of its roots. The relationshipbetween root reserves of starch and development of newly sproutingshoot material following fire is examined in S. latifolia afterspring and summer burns. During the initial 2-5 month periodafter fire, levels of stored starch in the roots fall by 50-75%,followed by a slow increase as plants reproduce and the attainmentof pre-fire starch levels by 1·5-2 years after the fire.Starch reserves of roots can be further reduced by shading theregenerating shoots to limit their input of photosynthates andalmost totally eliminated by monthly removal of successive flushesof new shoots over a 10-12 month period. New shoots continueto sprout until all the starch is eliminated. The data are discussedin relation to the fire-induced reproduction of S. latifoliaand its ability to thrive in very frequently burnt habitats.Copyright1993, 1999 Academic Press Fire response, Proteaceae, resprouter, shoot:root ratio, starch storage, Stirlingia latifolia