Will The Sunshine Coast's Endangered Allocasuarina Emuina Be Lost To Urbanisation Or Hybridisation?
The extreme morphological reduction and unique combination of traits which characterise the family Casuarinaceae can make taxonomic classification using physical attributes alone, extremely problematic. In addition, polyploidy, apomixis and hybridisation, known to have the potential for rapid speciation, are well documented within the genus Allocasuarina and are probably responsible for the large number of locally endemic species. The endangered Allocasuarina emuina is a dioecious, wind-pollinated shrub endemic to the heathlands and acid volcanic intrusions of the Sunshine Coast region of South-east Queensland, with 11 known populations occurring across a range of 36km. Substantial urban development over recent decades has resulted in significant habitat loss, causing considerable fragmentation and ongoing degradation through alterations to fire and hydrological regimes. A recovery plan aimed at downlisting A. emuina's conservation status by increasing the number of individuals in the wild and addressing key threats has been formulated. Management strategies for the conservation of existing populations and the enhancement and/or establishment of new populations are likely to be particularly dependent upon genetic information for their intelligent application. This study will use microsatellites, chloroplast DNA, and cytogenetics to genetically clarify the taxonomy, relatedness, and population structure of five Sunshine Coast species of Allocasuarina [A. emuina (E) A. thalassoscopica (E) A. rigida ssp. exsul (V), A. filidens (R) and A. littoralis (C)]. Specifically, it will elucidate the way in which genetic variability is partitioned within and among populations of A. emuina, whilst investigating aspects of the breeding system, and the potential for hybridisation with congenerics.