Assessing timber supply involves considering physical, biological, social and economic factors for all forest resource values. Physical factors include the area’s land features (including productive capacity of the soils) and physical characteristics of living organisms, especially trees. Biological factors include the growth and development of living organisms. Socioeconomic factors include the financial profitability of conducting forest operations, new harvesting and milling technology, and the broader community and social aspects of managing forest resources.
All these factors are linked. The financial profitability of harvest operations depends on terrain, physical characteristics of trees to be harvested, prevailing market conditions for forest products and required environmental protection standards. Forecasting the physical characteristics of trees in the future requires knowledge of their growth patterns. Assessing whether a stand is available for harvest may depend on how its harvest could affect other forest values such as wildlife or recreation.
These factors are also subject to uncertainty in key assumptions and to different points of view. Financial profitability changes as world timber markets change. Unforeseen losses due to fire or pest infestations will alter the amount and value of timber. The appropriate balance of timber and non-timber values in a forest is an ongoing subject of debate and is complicated by changes in social objectives over time.
Thus, before an estimate of timber supply is interpreted, the set of physical, biological and socioeconomic conditions on which it is based — and the uncertainties affecting these conditions — must first be understood.
Timber supply projections for TSAs and TFLs look far into the future — 200 years or more. These projections should not be viewed as static prescriptions that remain in place for that length of time. They remain relevant only as long as the information and forest management objectives on which they are based remain relevant. Regular re-analysis is required to ensure that the timber supply picture includes the latest information and knowledge and incorporates changes in management objectives and practices.
Timber supply analysis involves three main steps:
An essential component of the analysis is sensitivity analysis — examining how uncertainty in information can affect results. Sensitivity analysis varies the estimates and management assumptions used in the timber supply analysis to examine their effects on the harvest forecast. This highlights variables that could have large effects on timber supply, and identifies priorities for collecting information for future analyses. It can also clarify whether current best estimates provide safe bases for decisions or whether high uncertainty about important variables requires conservative decisions.
Appendix B contains a summary timber supply analysis for the southern portion of the Kalum Timber Supply Area, Prince Rupert Forest Region.
A discussion paper is produced to present the results of the timber supply analysis and socioeconomic assessment and to encourage public input. A public review period follows the release of these documents.
The Timber Supply Review has three major purposes:
The results of the review will also identify where improved information is required. This will help set priorities for research, data collection and further analysis.
Timber supply analyses for TSAs are conducted by ministry analysis teams with members representing the Timber Supply Section, local forest region and forest district. Analyses are conducted largely in-house and, because of short time frames, do not make use of external committees. The analysis team is responsible for obtaining the most current and best information from management plans and practices developed through public consultation. Both inputs to the analysis and analysis results are available to the public.
For TFLs, timber supply analysis are conducted by the licensee, and reviewed and approved by the Timber Supply Section. Analyses are based on current management practices that have been defined by the licensee in consultation with the local forest region, forest district and the public. The analyses also examine various management options.
Timber supply analyses focus on current forest management practices as specified in management plans and licence agreements for the TSA. These include guidelines for protecting forest resources, current silviculture methods and decisions on land use made by Cabinet. The current nature and capabilities of the local forest industry, including limitations and requirements of processing facilities, are also considered. Information from the Timber Supply Review will be used to determine where further investigations are necessary or desirable.
The Forest Act assigns responsibility for establishing AACs for British Columbia’s 71 Crown management units (36 TSAs managed by the Ministry of Forests and 35 industry-managed TFLs) to the chief forester. (Numbers of TSAs and TFLs have changed over the last ten years due to amalgamation and subdivision.) The provincial AAC is simply the total of these 71 individual AACs. AAC determination reflects a broad-based consideration of forest resource values and management objectives for each management unit. Analysis of the supply and sustainability of the timber resource is but one consideration.
The Forest Act (Section 7) requires the chief forester, in determining AACs, to consider:
(a) the rate of timber production that may be sustained on the area, taking into account:
(ii) the expected time that it will take the forest to become re-established on the area following denudation;
(iii) silvicultural treatments to be applied to the area;
(iv) the standard of timber utilization and the allowance for decay, waste and breakage expected to be applied with respect to timber harvesting on the area;
(v) the constraints on the amount of timber produced from the area that reasonably can be expected by use of the area for purposes other than timber production; and
(vi) any other information that, in his opinion, relates to the capability of the area to produce timber.
(b) the short- and long-term implications to the Province of alternative rates of timber harvesting from the area;
(c) the nature, production capabilities and timber requirements of established and proposed timber processing facilities;
(d) the economic and social objectives of the Crown, as expressed by the minister, for the area, for the general region and for the Province; and
(e) abnormal infestations in and devastations of and major salvage programs planned for, timber on the area.
Thus, AAC determination is not a calculation, but is based on judgment supported by technical analysis.
Public input is summarized in a report to the chief forester. The minister defines the government’s social and economic objectives for the province, which are then provided to the chief forester. In determining the AAC for the TSA, the chief forester considers input on technical forestry matters and the minister’s report. This determination and a statement of the rationale for the determination is released to the public along with the summary of public input.
Once the chief forester determines an AAC for a TSA, the minister of forests apportions it into different forms of licences and the local forest district administers harvest planning activities and cutting permit approvals. It is essential that forest management practices identified in operational planning (e.g., five-year development plans and cutting permits) are reflected accurately in the analysis of timber supply used to determine the AAC. These practices include retaining forested areas for streamside buffers, visual quality and old-growth reserves and altering harvest schedules and patterns to ensure adequate forest cover for wildlife habitat. If the analysis used to determine the AAC does not account for these practices, the resultant timber supply projection will be too high, which will affect the determination of AAC.
As of December 31, 1994, new timber supply reviews had been completed for 26 TSAs and new AACs had been set for 4 TSAs and 12 TFLs (see Section 3.6.2). For many of the older AACs, databases, assumptions and analytical techniques vary between management units. Analyses from the ongoing Timber Supply Review will result in new AAC determinations (based on standardized timber supply reviews) for all TSAs and TFLs by December 31, 1995. Table 3.8 Current allowable annual cuts for TSAs Table 3.9 Current allowable annual cuts for TFLs
