I am a tree pathologist and conduct research on micro-organisms, especially fungi, and their insect associates that cause diseases of trees.  This involves the early detection and identification of diseases, the characterization of the causal agents of tree disease and the elucidation of the epidemiology of the pathogens and the diseases they cause.

Current research projects include studies on the diversity, impact and epidemiology of Ceratocystis species and other Microascales on hardwood trees.  Here I am particularly interested in the arthropod associations with Ceratocystis species and factors that drive the distribution of these fungi. Another group of tree pathogens that I currently work on is the Cryphonectriaceae.  This group includes important pathogens of plantation Eucalyptus species, native South African Rapanea melanophloeos and many other tree species globally.  Other pathogens of interest include Fusarium circinatum, basidiomycete woodrot fungi in Ganoderma and Phellinus sensu lato, Puccinia psidii, the Botryosphaeriaceae and Phytophthora species.  Specific tree species on which my students and I am currently working include Adansonia digitata (Baobab), Encephalartos species (cycads), Euphorbia ingens (naboom), mangroves, commercial forestry species (Acacia mearnsii, Eucalyptus and Pinus species) and several other native tree species in South Africa.