Industry review
The industry review suggests that attempts by the Forest Service to update and improve some of the inventory data introduced uncertainty to the analysis. The uncertainty results from the lack of geographic relation of the data estimates to the forest cover. The review presents timber harvest forecasts using the unimproved inventory data for environmentally sensitive area reductions and for defining visual quality zones. Each forecast shows a very small increase over the Forest Service base case.
Other sources of uncertainty discussed in the industry review are:
• the use of modelling and analysis procedures that are not well suited for an area with a very fragmented land base
• the poor quality of some portions of the inventory
• the possibility that managed-stand yields are underestimated
The industry review presents a number of harvest forecasts that show increases in timber supply over the Forest Service base case. The alternative timber supply analysis inputs examined are:
• use of special site indexes where they exist in the inventory
• reversion of 50 per cent of the Timber Licence areas in a greened-up condition
• use of the upper end of the range of allowable denudation for visual quality objectives
• fertilization and commercial thinning in Douglas-fir stands
• allowance for negative bias in old-growth site index
• minimum harvest ages based on culmination of mean annual increment
• removing all visual quality objectives.
A suggested alternative harvest forecast to the Forest Service base case is presented that uses the following inputs:
• special site indexes where they exist in the inventory
• reversion of 50 per cent of the Timber Licence areas in a greened-up condition
• the upper end of the range of allowable denudation for visual quality objectives
• standard environmentally sensitive area reductions based on the inventory data
The forecast indicates that the current allowable annual cut could be maintained for two decades before declining by 5 per cent per decade over three decades to 410 000 cubic metres per year. It would remain at this level until decade 15 when it would increase to the long-term level of 455 000 cubic metres per year.
The industry review suggests that to improve analysis results, or at least decrease uncertainty in future analyses, the following should be undertaken:
• gather complete inventory data prior to analysis
• obtain field data on managed stands to support yield predictions
• investigate green up timing
• review old-growth site indices
• review land removals in light of modern integrated resource management
• clarify all policy issues with regard to timber availability, including setting targets for integrated resource management products
• use a geographic information system to prepare data to avoid pro-rata netdowns to the land base, and
• address land base fragmentation through improved modelling techniques
With the exceptions of the above issues and the suggested changes to analysis inputs, no recommendations were provided to improve the data, assumptions or computer model used in the Forest Service analysis.
Public Input
Industry input generally supports the industry review.
