|GUIDELINES for||. . .|
|Developing Stand Density Management Regimes|
Stand descriptions and management assumptions for coastal and interior scenarios, as they apply to untreated stands, are specified in Table A2-1. For convenience, these examples are based on the default values in TIPSY. Only the bolded information must be entered by the user to replicate the results. Note that some defaults depend on the region and district selected. Since the user can change TIPSY defaults, confirm all input data for untreated stands with Table A2-1 when reproducing these examples. Refer to the TIPSY online manual for detailed information and operating instructions. Note that:
Table A2-1. TIPSY input values for untreated stands of coastal hemlock and western interior lodgepole pine
Table A2-2 shows the pre-commercial thinning suite of runs that readers are encouraged to duplicate. After completing the untreated case (Table A2-1), select the thinning option in TIPSY, specify the post-treatment density given in Table A2-2, change the age range and steps temporarily and re-run the example. No other changes are needed until you generate the site values at the time of thinning (last row of Tables A2-3 and A2-4).13 To do that, set the "Analysis Base Year" so that discounting stops "At PCT Age." Discount the untreated stands to age 17 or 16 for hemlock and pine, respectively. Note that some calculations (e.g., harvest costs) may change in thinned stands.
Table A2-2. Treatment options, spacing costs and stand characteristics for coastal western hemlock and interior lodgepole pine density management regimes
The forest estate is managed under a silvicultural system that requires clearcutting at the physical rotation age (culmination of MAI). However, harvesting at the economic rotation age (culmination of site value) will be considered. The stand specifications are shown in the first section of Table A2-1. A minimum DBH of 12.5 cm is assumed for the future harvest. Note that the discount rate is 4%, and no increase in real - excluding inflation - product prices is expected. Costs are incurred for "Surveys" but not "Site Preparation." Pre-commercial thinning costs are given in Table A2-2. The future harvest is expected to use ground skidding equipment. Harvesting, hauling, milling and development costs, and product prices are given in Table A2-1.
Should stands be pre-commercially thinned - and, if so, to what density? Assume the silviculturist wants to compare the unthinned option with the three residual densities for hemlock or pine shown in Table A2-2.
Copyright 1999 Province of British Columbia