Insect pests and diseases of rainforest timber species grown in plantations

The Community Rainforest Reforestation Program (CRRP) and other planting programs included in their aims the long-term expansion of forest industries in north Queensland with the production of high quality rainforest timbers in plantations. Plantation productivity (survival, growth rate, form and yield) and quality of the timber product are influenced in part by plantation health which can be adversely affected by insect pests and diseases. Plantation development planning should include an assessment of the potential risks due to pests and diseases and site-related problems, facilitating appropriate species choice. Once established, regular plantation health surveillance should be incorporated into the management program, enabling early intervention where appropriate. A plantation health surveillance program: identifies pathogens, insect pests and their parasites and predators; enables early recognition of health change; identifies predictive patterns of pest and disease activity; facilitates the correlation between plantation productivity and pests and diseases; and contributes to a valuable bank of knowledge. Hardwood plantation research has recognised serious pests such as tip moths of the Meliaceae family as well as wood boring beetles and moths, sap sucking bugs and beetle defoliators associated with several tropical and subtropical eucalypts. Diseases such as Cylindrocladium leaf blight, Phellinus noxius and phytophthora root rot are also potential threats to rainforest replantings. Risk assessments and health surveillance were not conducted in the CRRP plantings, missing an opportunity to identify and manage the threat of pests and diseases in rainforest reforestation programs. Examples of appropriate risk assessment and health monitoring in hardwood plantation programs are the Department of Primary Industries’ Joint Venture scheme and Hardwoods Queensland project.