Canadian Forest Service Publications

Data and model validation methods used in developing the STIM growth model. 1993. Bonnor, G.M.; De Jong, R.J.; Boudewyn, P.A.; Flewelling, J.W. Pages 122-128 in J.K. Vanclay, J.P. Skovsgaard, and G.Z. Gertner, Editors. Growth and yield estimation from successive forest inventories, Proceedings: IUFRO conference. June 14-17, 1993, Copenhagen. Danish Forest and Landscape Research Institute, Lyngby.

Year: 1993

Issued by: Pacific Forestry Centre

Catalog ID: 3357

Language: English

Availability: Order paper copy (free)

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Abstract

To produce the STIM (Stand and Tree Integrated Model) growth model, data from approximately 1400 permanent sample plots were obtained from eight forestry agencies in the Pacific Northwest. A major portion of the model development time was spent in data and model validation.

Data validation procedures included:

  • screening tree and plot data to identify anomalies and missing data;
  • plotting variables to identify outliers and artificially generated data;
  • comparing growth rates and other derived variables to assess trends;
  • discarding plots with deficient data.

Model validation procedures included:

  • assessing the quality of individual growth predicting equations using various statistical analyses;
  • checking individual model prediction runs against real-life data;
  • comparing stand projections with the sum of tree projections;
  • analysing yield curves to assess long-term trends.