The Timberline critique generally supports the Forest Service analysis methodology and showed similar harvest level patterns. However, there were differences in the rate of harvest level decline and in the long-term harvest level.
Accordingly, the Timberline critique reports the following differences which had a positive effect on timber supplies:
• site indexes derived from thrifty stands to forecast growth, which had the effect of increasing overall growth rates by 14 per cent
• analysis units defined by species groups and site classification to provide finer and more detailed resolution
• future road allowances based on a five per cent loss rather than the seven per cent as used in the Forest Service analysis
• timber harvesting land base was increased by 7,500 hectares from the inoperable area to reflect increased timber market values
• use of commercial thinning to redistribute harvesting with positive effects on short-term timber supplies
The following differences were identified as reducing timber supplies:
• lower initial timber supply volumes for the Loughborough timber supply block from seven million to three million cubic metres to reflect an alleged error
• distributing the harvest pattern by reducing the harvest in the Kyuquot timber supply area by 40 per cent and increasing harvest levels in the Sayward and Loughborough timber supply areas
• removal of the Nasparti and the Tashish/Kwois protected areas
As well, two suggestions were provided that could have a positive effect on timber supplies:
• reducing green-up requirements by five years to provide a more gradual decline to long-term harvest levels
• modification of visual quality objectives to mitigate short-term impacts
In assessing the factors that could reduce or increase timber supplies, the Timberline critique stated that an initial harvest level reduction of 12 per cent was evident. However, in the long term, harvest levels could be nine per cent higher compared to the Forest Service analysis.
According to the Timberline critique, the application of forest cover constraints to model integrated resource management does not have clear goals, the ability to achieve the constraint results is not shown, and the implementation of the integrated resource management guidelines is based on broad assumptions rather than specific data.
In conclusion, the Timberline critique recommends that before the next timber supply review for the Strathcona, the following data and modelling uncertainties should be resolved:
• forest inventory updated for not satisfactorily stocked areas, update visual quality data and investigate timber volumes in the Loughborough timber supply block
• obtain field data on managed stands to support projected yield volumes
• review site indexes derived from old-growth forests and from sites with different reforested species
• obtain data on the dispersion of inoperable forested areas to examine options to meet forest cover requirements
• further research on appropriate silvicultural treatments and their associated effects on timber supply
The analysis methods and conclusions suggested by the Timberline critique were generally supported by a number of other submissions from the timber industry.
