Rationale and design for the Warra silvicultural systems trial in wet Eucalyptus obliqua forests in Tasmania

Clemfell, burn and sow (CBS) is the prescribed silvicultural technique for wood production from lowland wet eucalypt forests. Its widespread adoption raises concerns, particularly due to initial aesthetics, a reduction in late successional species and structures, and a decline in the special species timbers resource when rotations of about 90 years are used. Cases for and against the CBS technique are presented. The Warra silvicultural systems trial is being established in the period 1998-2002 to compare CBS with five alternative treatments that were selected after a review of silvicultural systems applied in 'Wet forests elsewhere. The alternatives include CBS with understorey islands, stripfell/patchfell, 10% dispersed retention, 30% aggregated retention and single tree/small group selection. Prescriptions for the six treatments and indicators for monitoring their initial pe1formance are described, along with expectations and limitations of the Warra trial.