The potential role of a Phytophthora species in Eucalyptus gomphocephala (tuart) decline in southwest Western Australia

Scott, P., Barber, P., Burgess, T., Shearer, B., Colquhoun, I., Jung, T. and Hardy, G. (2007) The potential role of a Phytophthora species in Eucalyptus gomphocephala (tuart) decline in southwest Western Australia. In: 11th International Mediterranean Ecosystems (MEDECOS) Conference (2007), 2 - 5 September, Perth, Western Australia.

Abstract

Introduction: Eucalyptus gomphocephala is a unique keystone canopy species endemic to a narrow (5-10 km wide) coastal strip approximately 300 km in length in the southwest of Western Australia. E. gomphocephala is undergoing a significant decline throughout large sections of its remnant distribution within Yalgorup National Park, and in some areas resulting in 100% mortality (Barber et al. 2007). Fine feeder root damage and root necrosis has been observed in declining E. gomphocephala across a range of sites. In addition, tree injection trials with phosphite, a chemical known to induce host defence responses to Phytophthora species, have resulted in increased crown vigour and health. These observations indicate that a Phytophthora species could be associated with tuart decline. The aim of the current study was to determine whether Phytophthora species are associated with E. gomphocephala decline.