Conservation biology of the rare species Conospermum undulatum and Macarthuria keigheryi in an urban bushland remnant

We evaluated the utility of a focussed, short-duration research program for investigation of two rare species that occur within an urban bushland remnant, with application for improving conservation management and translocation outcomes. Conospermum undulatum Lindl. is listed as Threatened and Macarthuria keigheryi Lepschi is listed as Vulnerable under the (Australian) Federal Environment Protection and Biodiversity Conservation Act 1999. The C. undulatum population lacked evidence of juvenile plants, indicating either lack of a suitable germination cue or failure of seedling establishment. The M. keigheryi population was browsed heavily by feral rabbits where exposed and thrived when sheltered within unpalatable vegetation from rabbits. Seeds of M. keigheryi were rapidly removed in an ant cafeteria-style experiment, although seeds of the related Macarthuria australis and an 'outgroup' species, Gompholobium tomentosum, were removed at equally high rates. Seed viability was high in M. keigheryi, but variable in C. undulatum. Germination rates, in untreated fresh seed, were 11% for C. undulatum and 0% for M. keigheryi and increased to 27 and 3%, respectively, when treated with gibberellic acid. Maximum strike rates for cuttings of 33 and similar to 75% were obtained for C. undulatum and M. keigheryi, respectively. Cutting-grown plants of M. keigheryi flowered and seeded profusely in the nursery within 7 months, providing a highly effective seed-orchard resource for research and conservation seed banking. Genetic fingerprinting (AFLP) indicated that the C. undulatum population at Perth Airport was not genetically distinct from nearby C. undulatum populations, despite its relatively high variability in leaf morphology. All C. undulatum populations contained moderate to high levels of genetic variation, with the percentage of AFLP markers polymorphic ranging from 48.6 to 64.9%, and heterozygosity from 0.167 to 0.202. Overall, the knowledge gained from this program of short duration will enable informed management and will underpin successful population enhancement through future translocations.