Examples exist across the country of plants introduced into native vegetation communities that originated from overseas or other parts of Australia. These plants naturalise by reproducing successfully in the wild over several generations, and given the right conditions undergo a rapid growth in population leading to a reduction in the integrity and conservation value of native biota. Originating in the Mediterranean region, O. europaea was imported into Australia and cultivated for its high oil content. This thesis examines the impact of O. europaea on e. microcarpa woodland, the history of and processes leading to invasion, and the relevance of the plant as an environmental weed. Evidence in this thesis suggests that O. europaea invasion can lead to a considerable reduction in native species richness and abundance in E. microcarpa woodland.
Invasion also alters the canopy structure of the woodland.
Species most at risk are E. microcarpa, Acacia pycnantha and Dodonaea viscosa. It is argued that the reduction in light infiltration caused by the dense canopy of O. europaea prevents regeneration of native species. O. europaea should be considered as a serious threat to the integrity of vegetation communities it invades and be given the status of a serious environmental weed. An argument is provided in this thesis that O. europaea fits into the category of environmental weed.