The effectiveness of seed trees on carryover coupes in HEMS forests of East Gippsland.  G. M. Dooley, M. T. Lutze and M. D. Murray.  January 2006.  14pp. (unpubl.)

SUMMARY

Significant research into High Elevation Mixed Species (HEMS) silviculture in East Gippsland has been required over three decades due to the often poor success of post-harvest regeneration. Seed trees play an important role in regeneration, however, there is little information on the effectiveness of seed trees on coupes that are carried over to the following year for site preparation. This study forms part of that research.

The aims of this study were to:

• Determine the loss of seed trees in HEMS coupes carried over to the following year, between time of harvesting and site preparation.
• Determine the loss of seed from seed trees in HEMS coupes carried over to the following year.

Three carryover coupes were selected (two in 1999/2000 and one in 2001/2002) with 9-11 seed trees from each coupe being selected for study after harvesting completion. Measurements of species type, percentage of live crown and percentage of damage were recorded for each seed tree at three to four months after harvesting completion. Percentage of live crown was again recorded, seven months later at two weeks prior to slash burning. Seed traps were placed near each seed tree and the shed seed was collected monthly. The seed was germinated to determine the number of viable seeds. Seed crop assessments were performed to estimate the amount of capsules on seed trees of the 2001/02 coupe. A sample of capsules was collected and seed from capsules were tested for viability.

The results indicated that:

• On carryover coupes, most seed trees remain standing and retain crown size in the 10-12 month period between harvesting and slash burning. Therefore the number and spatial distribution of seed trees selected on planned carryover coupes should be about the same as on non-carryover coupes.
• Density and quantity of viable seed of the older seed crop (i.e. from flowering events before harvesting) may decrease between harvesting and slash burning. However, new seed crops may develop, mature and the quantity of viable seed may increase. If there is a high likelihood of the coupe being carried over, then forest officers should select seed trees with an oncoming crop.
• Seed crops on seed trees should be monitored between harvesting and slash burning to determine if the developing seed crop satisfies the seed crop assessment kit tables. Alternatively, seedfall monitoring using seed traps after burning could be carried out. Artificial sowing rates, if any, can then be determined.