DOES THE RARE BANKSIA-GOODII HAVE INFERIOR VEGETATIVE, REPRODUCTIVE OR ECOLOGICAL ATTRIBUTES COMPARED WITH ITS WIDESPREAD COOCCURRING RELATIVE BANKSIA-GARDNERI

Banksia goodii (rare) and B. gardneri var. gardneri (widespread) are c losely related rhizomatous evergreen subshrubs of south western Austra lian scrub-heath and woodland. B. goodii is restricted to sixteen popu lations, most of which are remnants on roadsides due to landscape frag mentation from agricultural activities. Bioclimatic profiles indicate that B. gardneri spans a wider range of climates than B. goodii. Howev er, their post-fire survival and resprouting vigour, rates of seedling growth and soil penetration and susceptibility to seedling predators are similar. Both have the potential for geographic range extension, e specially B. goodi. Seedlings of both species survived for at least 3 years at sites with 2 (but not 3) months shorter and 1 month longer gr owing seasons than experienced by natural B. goodii populations. Seedl ing establishment did not occur in the absence of fire and was low (1. 3% of released intact seeds for B. goodii) even following en masse rel ease of seeds after fire. Sowing of intact seeds, especially in cleare d areas and with protection from herbivores, increased this to 35%. Fi re survival among adults of both species was 100% following two fires. B. goodii, which roots along its rhizomes, produces ramets, while B. gardneri, with a lignotuber instead, does not. Seed production, pre-di spersal granivory and canopy seed storage are low but similar for both species, although B. gardneri has a superior level of germination. Th e biology of B. gardneri thus provides few insights as to why B. goodi i is rare. There were no differences in topo-edaphic attributes, commu nity structure, shading or litter cover between localized sites where either species occurred alone or together. Differences in present or p rehistoric fire regimes, clearing (habitat fragmentation), susceptibil ity to generalist fungal pathogens, or impacts of alien invasives, can not explain the distribution of B. goodii relative to B. gardneri. The rarity of B. goodii may be a result of its recent origin, habitat spe cialization (dense woodland), and the impacts of habitat fragmentation within its current range, rather than inferior vegetative, reproducti ve and/or ecological attributes.