Silviculture impacts on Yield Lumber Value and Economic Return (SYLVER)

Silviculture impacts on Yield Lumber Value and Economic Return (SYLVER) is a system that helps forest managers evaluate impact at the stand level. It links TASS with a string of software programs that predict product recovery (logs and lumber) and the associated financial return for various silvicultural regimes.

The SYLVER system itself is not distributed to the public. However, a fixed suite of SYLVER-generated log and lumber output tables are part of TIPSY, as is SYLVER’s financial analysis program, FAN$IER. Those users requiring greater flexibility than TIPSY provides can request custom SYLVER runs.

SYLVER’s main components and information flow are as follows:

  • TASS is the growth and yield model providing predictions of individual tree dimensions and wood characteristics, in response to various silviculture treatments, such as:
    • Log taper
    • Ring width
    • Knot size
    • Juvenile wood profile
  • BUCK  receives the TASS output and optimizes log bucking to maximize value. 
    • If logs are the specified product, the log output file is passed directly to GRADE.
    • Otherwise, the output file is passed to SAWSIM ((Sawmill Simulator).
  • SAWSIM selects a sawing pattern that maximizes value given the specified sawmill configuration and lumber specifications. SAWSIM also quantifies mill residuals in the form of:
    • Chips
    • Sawdust
    • Shavings
    • Trims
    • Bark

NOTE: All these are reported in oven-dry tonnes (ODT).

  • GRADE receives the lumber output file from SAWSIM and grades each log or piece of lumber according to standard industry grading criteria. Optionally, lumber grades can be adjusted (degraded) for juvenile wood content
  • FAN$IER receives the graded log and lumber files from GRADE and the silviculture regime specifications from TASS. It then performs economic analyses using its default costs and prices, or those specified by the user

 The SYLDEMO presentation further explains SYLVER and demonstrates its application in silviculture investment analysis.

Di Lucca, C.M. 1999. TASS/SYLVER/TIPSY: systems for predicting the impact of silvicultural practices on yield, lumber value, economic return and other benefits. In: Stand Density Management Conference: Using the Planning Tools. November 23–24, 1998, Colin R. Bamsey [Ed.] Clear Lake Ltd., Edmonton, AB. pp. 7–16.

Hatton, J.V. and K. Hunt. 1989b. Unbleached Kraft Pulps. In: Second growth Douglas-fir: Its management and conversion for value, Kellogg, R. M. (eds.). Forintek Canada Corp., Spec. Publ. No. SP-32, Vancouver, B.C. pp. 87-113.

Hatton, J.V. and S. S. Johal. 1989. Refiner Mechanical Pulps. In: Second growth Douglas-fir: Its management and conversion for value, Kellogg, R. M. (eds.). Forintek Canada Corp., Spec. Publ. No. SP-32, Vancouver, B.C. pp. 114–129.

Kellogg, R.M. (Editor), 1989. Second growth Douglas-fir: its management and conversion for value. Forintek  Canada Corporation, Vancouver, B.C., Special Publication No. SP-32, 173 pp.

Mackay, J.F.G. 1989.  Kiln Drying Lumber.  In: Second growth  Douglas-fir: Its management and conversion for value, Kellogg, R. M. (eds.). Forintek Canada Corp., Spec. Publ. No. SP-32, Vancouver, B.C. pp. 75–77.

Middleton, G.R. and B.D. Munro. 1989. Log and Lumber Yields. In: Second growth Douglas-fir: Its management and conversion for value, Kellogg, R. M. (eds.). Forintek Canada Corp., Spec. Publ. No. SP-32, Vancouver, B.C. pp. 66–74.

Mitchell, K.J. 1987. Predicting the impact of silvicultural treatments on yield, products and value. In: H.N. Chappell and Douglas A. Maguire (Editors). Predicting Forest Growth and Yield: Current Issues, Future Prospects. College  of Forest Resources, Univ. Wash., Seattle, Wash. Inst. For. Resources Contribution No. 58. pp. 44–60.

Mitchell, K.J., R.M. Kellogg, and K.R. Polsson. 1989a Silvicultural treatments and end-product value. In: Second growth Douglas-fir: Its management and conversion for value. A report of the Douglas-fir Task Force, Kellogg, R. M. (editors).  Forintek Canada Corp. Spec. Publ. No. SP-32, Vancouver, B.C. pp.  130–167.

Mitchell, K.J., R.M. Kellogg, and K.R. Polsson. 1989b. SYLVER: The link between silvicultural practices and financial return. Can. For. Ind. pp. 38–42.

Mitchell, K.J., R.M. Kellogg, and K.R. Polsson. 1991 (updated version from 1989). Silvicultural treatments and  end-product value. In: Second growth Douglas-fir: Its management and conversion for value. A report of the Douglas-fir Task Force, Kellogg, R. M. (editors). Forintek Canada Corp. Spec. Publ. No. SP-32, Vancouver, B.C. pp. 130–167.

Mitchell, K.J. and K.R.  Polsson. 1993. SYLVER: A decision-support system for silviculture. In: Les modeles de  croissance forestiere et leurs utilisations (Forest growth models and their uses), November 18–19, 1993, Quebec City, PQ, Canada, (editor) C. Ung. (editor.). Nat. Res. Canada, Can. For. Serv., Sainte-Foy, Que. pp. 34–44.

Mitchell, K.J. 1995. Simulate the Treatment Before Pruning the Stand. In: D.P. Hanley, C.D. Oliver, D.A. Maguire, D.G. Briggs, and R.D. Fight (Editors). Forest Pruning and Wood Quality of Western North American Conifers. Coll. For. Res., Univ. Wash., Seattle, Wash. pp. 281–290.