Forest health surveillance in Victoria

Abstract

Summary Forest health surveillance (FHS) has been undertaken in Victorian native forests and plantations on an ad hoc basis since the early 1960s in response to incursions and outbreaks of native and introduced insect pests and plant pathogens, such as sirex wood wasp, Monterey pine aphid, Phytophthora dieback, phasmatids and other defoliators. The purpose of surveillance is to provide a broad overview of forest health and data for land managers to allow them to take appropriate strategic decisions and manage risks to their estate. Early targeted FHS in Victoria consisted mainly of drive-through surveys with aerial surveillance where required to determine the extent of a particular damaging agent. In 1991, a plot-based surveillance system targeting high-risk sites was developed to monitor levels of Dothistroma disease. These plots were used to trigger more intensive surveillance (e.g. aerial) to enable early management intervention once the levels reached predetermined thresholds. In 2001, a broader plot-based monitoring system was implemented for HVP Plantations as part of its risk management program to determine the status, changes and trends in tree health on an annual basis, and provide data for management decisions to control outbreaks threatening the health of plantations. This paper describes the establishment of a plot-based monitoring system, combined with supplementary surveys to provide information on the extent and damage potential of pest agents in the HVP Plantations estate, and its possible application in native forests.