Project: 1999-02. Report - Canopy Indicator Assessment: A Method for Monitoring Brushtail Possum (Trichosurus vulpecula) Damage to Pine Plantations
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Date: 2003 Author: Ian Payton and Chris Frampton Publication: Report Project reference: 1999-02 Full report is available from: |
Executive summary:
Brushtail possums (Trichosurus vulpecula) now occupy most areas within New Zealand that are suitable for plantation forestry. Possums browse the terminal shoots of pine seedlings, bite and strip the bark of young stems to get at the cambial tissue, remove needles and cones, and bend or break terminal shoots and lateral branches in the upper portion of the tree. Damage is most commonly reported from young stands. It rarely kills established trees, but can lead to reduced vigour, loss of apical dominance, and an increased incidence of fungal diseases. Where possums are suspected of damaging pine plantations forest managers need to be able to determine when control is required, which areas should have priority, whether control achieves its goals, and when further control measures will be necessary. Reliable inferences and predictions about possum damage can only be obtained from robust, quantitative data. In this manual we discuss the design of surveys to monitor possum damage in pine plantations, and describe a new method for assessing possum damage to pine trees. Canopy Indicator Assessment is a scoring method that uses ground–based assessment of individual trees to determine the nature and extent of possum damage within pine stands, and the degree to which this is reduced as a result of possum control operations. Options for analysing data are outlined.Full report is available from:
Landcare Research
PO Box 40
lincoln 7640
