Robert Lamont

The Swamp Orchids Phaius australis and P. bernaysii are iconic and beautiful terrestrial orchids that occur in disjunct populations along Australia's east coast and in isolated inland locations. However, these orchids are endangered due to illegal collection in the past and continued habitat loss and fragmentation. Future climatic change threatens to push such species with small populations, limited connectivity and narrow environmental tolerances to extinction. In this study we have investigated the viability and persistence of the species by combining genetic and demographic studies across a 2000 km range. Thirty-four populations were sampled from Cooktown, North Queensland to mid-north coast New South Wales. NextGen sequencing was utilised to develop 22 microsatellite marker and population genetics analyses utilised to explore diversity, variation, inbreeding and spatial patterns of diversity across the latitudinal range. Population sizes ranged from extremely small (two individuals) to 100's of plants. We found low genetic diversity and variation across the species range, with little indication of inbreeding but some evidence of clones. Genetic bottlenecks were recognized in some populations known to be recovering from recent rapid population loss. Patterns of post-colonisation divergence from Phaius tancarvilleae, a widespread tropical co-gener will be presented. The persistence of populations in current locations under changed climatic conditions and the ability to follow a climatic niche southward will be discussed in the context of possible assisted translocations.

Identification of the three more-­or-­less sympatric species of Allocasuarina sect. Cylindropitys on the North Coast of New South Wales is difficult: the widespread A. littoralis and A. defungens and A. simulans; the last two gazetted as ‘Threatened’ and restricted to the Nabiac area. In exposed coastal sites plants form shrubs up to 2 m regarded as hybrid 1) A. littoralis X A. defungens, 2) a maritime form of A. littoralis, 3) a form of A. defungens, or 4) A. emuina. Have environmental conditions resulted in dwarfing of A. littoralis without genotypic divergence? Morphometric data of plants from several North Coast sites was analysed using PATN and assessed along with data from SEM and chromosome number. The results of the study, along with exploratory DNA fingerprinting, will be discussed. Delimitation of species will be considered within the context of polyploidy, apomixis and clonal reproduction.

Boronia rivularis is a rare heathland shrub restricted the Sunshine Coast of Australia, an area undergoing rapid urbanisation. A development proposal is planning to translocate a population of this species from the southern end of its range. A previous study of genetic diversity in B. rivularis found a nearby population to be highly inbred and genetically depauperate compared with other populations. The study also found that, inbreeding was significantly positively correlated with population density. The population on the development site was mapped using a differential GPS and identified dense and sparser subpopulations and was used for initial translocation planning. We sampled the development site B rivularis within four sub populations using the same methods and markers as the previous genetic analysis. This study revealed genetic diversity was high in some subpopulations but progressively decreased as plant population density and fixation indices increased across the site in the direction of the neighbouring depauperate population. The large population size and the genetic structuring suggest the nearby population may have arisen from this one and highlights the benefits of retaining some of the existing population on the site. The results also indicate that any compensatory translocation program needs to mimic this the genetic substructuring. Largely due to its lower density, the subpopulation with the highest diversity and lowest inbreeding had not been previously valued as highly for translocation as the more conspicuous denser subpopulations. This study has highlighted that high population density does not necessarily indicate genetically fitter or more diverse subpopulations.

Boronia rivularis is a rare healthland shrub restricted to the Sunshine Coast of Australia, an area undergoing rapid urbanisation. A development proposal is planning to translocate a population of this species from the southern end of its range. A previous study of genetic diversity in B. rivularis found a nearby population to be highly inbred and genetically depauperate compared with other populations. The study also found that inbreeding was significantly positively correlated with population density. The population on the development site was mapped using a differential GPS and identified dense and sparser subpopulations which were used for initial translocation planning. We sampled the development site B. rivularis within four sub populations using the same methods and markers as the previous genetic analysis. This study revealed genetic diversity was high in some subpopulations but progressively decreased as plant population density and fixation indices increased across the site in the direction of the neighbouring depauperate population. The large population size and the genetic structuring suggest the nearby population may have arisen from this one and highlights the benefits of retaining some of the existing population on the site. The results also indicate that any compensatory translocation program needs to mimic this genetic substructuring. Largely due to its lower density, the subpopulation with the highest diversity and lowest inbreeding had not been previously valued as highly for translocation as the more conspicuous denser subpopulations. This study has highlighted that high population density does not necessarily indicate genetically fitter or more diverse subpopulations.