A disjunct population of Eucalyptus globulus ssp Bicostata from South Australia

A population of Eucalyptus globulus ssp. bicostata was recently discovered at Mr Bryan (SA) which is more than 600 km from the nearest other populatio n of this taxon. The aim of this study was to determine whether this popula tion is natural or whether it might have been planted after the arrival of pastoralists to the area. To achieve this aim we used RAPD molecular marker analysis of a large (10 m diam) lignotuberous stand of E. globulus ssp. bi costata that roughly formed a ring. The RAPD analysis indicated no differen ces between samples taken from the lignotuberous stand, although individual s from outside it were all different from it and from one another Because t he lignotuberous stand of E. globulus ssp. bicostata is likely to originate from a single individual and is very large, it is likely to be very old (p ossibly as old as 4000 years) and this would imply that the population was not established by pastoralists. How did the E. globulus ssp. bicostata bec ome established on Mt Bryan? Four possibilities are discussed, namely, natu ral long distance seed dispersal, seed dispersal by humans before the arriv al of pastoralists, long distance pollen dispersal and connection to the Vi ctorian Eucalyptus globulus Ssp. bicostata forest in the past.