UBC Theses and Dissertations
Some non-linear functions fitted to actual volume-age data Sagary-Nokoe, Tertius
Seven non-linear functions are fitted to eight groups of data, and the best three functions selected for each group. Selection is based on the correlation index, mean bias and the partial and overall standard error of estimate. Most of the groups of data are adequately described by the Gompertz curve [formula is not included], where a is the ultimate limiting value, G is a parameter defining the point of inflection (maximum current annual increment), c defining the curve shape, V is volume in cubic feet (close utilization standard) and X is age in years. Comparison of the functions with the British Columbia Forest Service volume/age curves (VAC.s) , where appropriate, indicated that these are not very different from each other. It might, therefore, be possible to describe some of the existing VAC's by suitable non-linear functions.
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