Translocation of the desert phebalium to Yookamurra Sanctuary, South Australia

Summary

Desert phebalium (Phebalium glandulosum ssp. macrocalyx), an Endangered shrub in South Australia and the western-most, genetically distinct outlier of a wider distribution across New South Wales and Queensland, was translocated by the Botanic Gardens of Adelaide to test how propagule type affects establishment in secure, predator-fenced habitat outside its threatened roadside remnants. Following a 1991 pilot at Yookamurra Sanctuary and Brookfield Conservation Park, where all Brookfield transplants died within six months from drought and grazing, the main 1992 trial planted cutting-derived and seedling propagules at two favorable, low-lying Yookamurra sites sourced from wild Yorke Peninsula populations. Survival diverged sharply between propagule types: after 20 years, seedlings reached 90% survival and grew taller than cuttings, which survived at only 55%, though flowering and seed-set eventually converged for both types by year three, at rates comparable to wild plants. Natural recruitment did not appear until 18 years after translocation, when 27 seedlings were found clustered near parent plants, rising to 49 the following year, showing the full establishment-to-recruitment cycle took at least 16 years. No herbivore damage was observed at Yookamurra, though drought years between 2006 and 2009 caused some losses, and encroaching Ward's weed poses an ongoing risk to future recruitment. The project rates itself Successful, demonstrating the species can be established at suitable secure sites and confirming seedlings are the preferred founder stock over cuttings.