Translocation of four rare ironstone endemic species onto a pre-mined area at Beenup in SW Australia

Summary

Four rare ironstone-endemic shrubs restricted to winter-wet habitats in southwestern Australia, Lambertia orbifolia subsp. Scott River Plains, Banksia nivea ssp. uliginosa, Grevillea brachystylis subsp. australis and Darwinia ferricola, all threatened by clearing, weeds and the root pathogen Phytophthora, were translocated by Kings Park Botanic Gardens onto a rehabilitated 0.2-hectare former mineral sand mine site at Beenup as a pilot test of post-mining habitat restoration. After removing an 18-meter clay stockpile, two seed-bank-rich soil types were spread over the fenced, irrigated site, and propagation material, mostly wild-collected seed except for cutting-derived Darwinia, was sourced from nearby nature reserves, roadside populations and the mine site itself, planted in blocks to compare survival and reproduction by source and soil type. Genetic analysis found little differentiation among most source populations, though the Governor Broome Road and Nature Reserve center populations of one species proved significantly distinct. Early monitoring showed lower-than-expected losses despite harsh, wind-exposed, wet conditions, with some deaths from phytophthora and pythium controlled through a phosphoric acid spraying program; by the time formal monitoring ended in 2007, all four species were flowering and setting seed, and Grevillea was already recruiting from the soil seed bank. A 2009 follow-up visit found all species still thriving and producing abundant viable seed, with the Grevillea and Lambertia recruiting in numbers likely sufficient for self-sustaining populations, though Darwinia and especially Banksia recruitment remained minimal. The project rates itself Highly Successful, crediting rigorous science-based site preparation and strong collaboration with mine operators and trained volunteers.