HEMS regeneration decision tree: review of operational experience.  J. D. Delbridge.  May 1999.  23pp. (unpubl.)

SUMMARY

The High Elevation Mixed Species (HEMS) Regeneration Decision Tree (Sebire & Geary 1995) was developed on the recommendation of the Eastern Research and Development Action Group (ERDAG) HEMS Regeneration Working Group. This decision support system for planners and operators, was prepared in chart form from a number of guiding principles that were believed to be necessary for the successful regeneration of HEMS forests.

Proposed refinement of the Regeneration Decision Tree (RDT) was performed through analysing its application to a number of operational coupes and suggesting changes that could be made to improve its effectiveness.

A total of thirteen HEMS coupes were selected for study, one that was harvested in 1993/94, seven in 1994/95, four in 1995/96 and one in 1996/97.

Even when the RDT was followed, it was found to give variable regeneration results. However, deviation from the RDT pathways resulted in a higher rate of failure.

Recommendations made to improve the RDT include:

• Refine the definition of 'problem' coupes to include indicators specific to individual Districts, or groups of forest blocks.
• Review the 800 m elevational limit applying to the use of seed trees, i.e. consider the use of seed trees above 800 m.
• Include monitoring before site preparation on all RDT pathways.
• Allow for changes which occur during the life of a coupe by reviewing and re-defining the coupe type, where appropriate.
• Revise the notes accompanying the RDT, including reference to more recent HEMS reports.
• Emphasise the essential role of monitoring in identifying the effects of factors beyond Departmental control.