Distribution and potential impact of Opuntia aurantiaca (tiger pear) along Little River, Victoria
David Dance, Robyn Adams and Dianne Simmons, School of Ecology and Environment, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia.
Tiger pear Opuntia aurantiaca is a sterile species which is dispersed vegetatively along water courses. It is a major pest in New South Wales and Queensland, but is recorded from only five locations in Victoria. The main infestation is along Little River between Ripley Bridge and the River outlet into Port Phillip Bay. The potential for significant spread of tiger pear downstream is of concern because of the Ramsar wetlands. Tiger pear infestation is more frequent on the westerly side of Little River (64%) compared with the easterly side of the river (36%). The upstream sections of Little River are more severely infested than the downstream sections, and vegetation loss and soil degradation are more severe. Along the downstream sections, tiger pear is restricted to the major river bends, but is beginning secondary spread. It is likely tiger pear will spread to other watercourses. Small populations, mostly single plants, have already dispersed into swamps near the mouth of Little River.
Plant Protection Quarterly (2003) 18 (3) 107-109.