The technical critique states that redefining analysis units allows the current harvest to be maintained for 70 years (compared to 60 years in the Timber Supply Analysis Report) before declining to a long-term harvest level of 361,000 cubic metres per year (20 per cent above the Timber Supply Analysis Report base case).
The critique suggests the timber growth projections used in the Ministry of Forests analysis are conservative because:
• the timber productivity estimates (site indexes) based on existing over-mature forests are lower than would be expected for regenerated forests on the same sites; the critique maintains that site index data are unreliable on 97 per cent of the land base
• the effects of density and competition control treatments are not considered
The critique estimates that the long-term harvest level will be 475,000 cubic metres per year when projected timber volumes for managed forests are applied (58 per cent above the Timber Supply Analysis Report base case).
The critique notes the timber harvesting land base (areas considered feasible or economical to harvest) will vary with market conditions. Current increases in log prices are expected to increase the operable area, thereby increasing the long-term harvest level. Increasing the currently defined operable land base by nine per cent results in a long-term harvest level of 403,000 cubic metres per year.
The critique also states that the reduction of 8.3 per cent of the land base for roads and landings is too high. By reducing this to six per cent, the long-term harvest level can be increased by about two per cent.
The critique predicts the combined impacts of redefined analysis units, increases in site index values and land base, a decrease in area for roads and removal of the constraints for integrated resource management, would allow the current harvest to be maintained for 170 years before declining to a long-term harvest level of 518,000 cubic metres per year.
The critique notes the current harvest level can be sustained the with the additional management constraints of the Forest Practices Code.
