|GUIDELINES for||. . .|
|Developing Stand Density Management Regimes|
The stand density management decision support process should be the analytical prerequisite for biologically and economically feasible silviculture and stand management prescriptions. The matrix in Table 1 illustrates three possible decisions regarding the validity of individual stand density management projects. It indicates the expected outcomes of strategic and tactical analyses based on the "biological concepts," "economic principles," and "forest-level considerations" sections.
Three decision criteria must be considered: biological feasibility, economic feasibility and forest-level considerations. Biological and economic feasibility are based on a timber production perspective. Forest-level feasibility is a test of whether the treatment or project contributes to forest-level considerations, including both timber and non-timber objectives.
The test of biological feasibility is the most important of the three feasibility tests. Any treatment objective which is biologically infeasible for any reason must not be considered further. Forest resource stewardship also demands that silviculture practices should not compromise the structural integrity or long-term production potential of a stand.
Table 1. Examples of common decision outcomes and interpretations resulting from the evaluation of hypothetical stand density management projects
Suitable, unsuitable and provisional are relative measures of how closely a project meets the test of all three criteria. The last row in the matrix indicates the project suitability decision, and provides either a justification or recommends a subsequent procedure.
In the first decision scenario (column 2) the proposed density management project is expected to produce a positive biological response, generate a positive stand-level economic outcome, yet result in a negative forest-level effect. The appropriate decision in this case is that the project is unsuitable because it confounds achievement of forest-level objectives.
The second scenario (column 3) is similar to the first, except the expected impact of the project at the forest level is neutral, instead of negative. This changes the decision to provisional, and a recommendation to proceed with the project depends on the availability of silviculture funds and the inclination of those managing the forest estate.
The third scenario (column 4) represents the most favourable measure of project suitability. Positive results were measured for all criteria. The resulting decision makes the project suitable since it contributes positively to management objectives, and is biologically and economically feasible.
The positive (biological), negative (stand-level economic), and positive (forest level) combination in scenario four (column 5) results in a provisional decision, and a recommendation for minimum cost ranking. This means that the proposed project could be undertaken because of its capacity to yield a positive contribution to forest management objectives. However, there may be other projects also meeting objectives but capable of generating a more favourable (or less costly) economic outcome. Where funding is available, all stand density management activities would be ranked in order from least to most costly. Stand density management projects would be undertaken in this order to a point where total density management program costs equalled available funds.
In the fifth scenario (column 6) the density management project is expected to yield a positive biological response, a negative stand-level economic response, and a neutral forest-level response. The project in this instance is unsuitable. If a project has a positive biological impact, neither contributes to nor detracts from achievement of forest-level objectives, yet provides no net economic gain at the stand level, it would be difficult to justify the expenditure of silviculture funds. Practitioners should instead consider alternative projects or investments that provide greater returns and/or contribute more to achieving forest estate management objectives.
Copyright 1999 Province of British Columbia