Translocations of the critically endangered spiny daisy in the Mid-North of South Australia

Summary

The spiny daisy (Acanthocladium dockeri), a Critically Endangered South Australian shrub thought extinct until its 1999 rediscovery revealed just five surviving wild populations, each a single distinct genotype confined to degraded roadside grassland or shrubland reserves, exhibits vigorous root-suckering but virtually no seed-set, leaving it unable to reproduce sexually in the wild. The Department for Environment and Heritage has been establishing safeguard translocated populations for each genotype from easily propagated cuttings: a Rusty Cab population of 24 plants reached 87.5% survival after 12 months at a council reserve, and a Telowie population of 24 plants, the species' first on a conservation reserve, achieved 71% survival despite drought conditions. A controlled 400-plant experimental trial testing weed control, snail baiting and tree guards found tree guards alone drove significantly higher survival (78%) than any other treatment or combination, chiefly by protecting young shoots from rabbit and hare grazing and retaining soil moisture, demonstrating that expensive site preparation is often unnecessary. A field cross-pollination trial mixing all five genotypes together found no evidence of successful inter-genotype fertilization or seedling establishment after monitoring flowering plants, suggesting the species may be permanently restricted to its five known genotypes with no capacity to adapt genetically. Display populations have also been established at five public gardens for education. Major difficulties included fragmented, degraded habitat limiting suitable translocation sites, prolonged regional drought, and historically inconsistent funding, since resolved through corporate sponsorship. The project rates itself Successful, citing strong translocation methodology and inter-agency collaboration despite the unresolved cross-pollination barrier.