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Acta Forestalia Fennica no. 174 | 1981

Category: Article

article id 7621, category Article
Pekka Kilkki, Martti Varmola. (1981). Männyn runkokäyrämalleja ja niiden sovellutuksia. Acta Forestalia Fennica no. 174 article id 7621. https://doi.org/10.14214/aff.7621
English title: Taper curve models for Scots pine and their applications.
Original keywords: runkokäyrämalli; menetelmät; mänty

Taper curve models based on simultaneous equations were derived. The data consisted of 492 Scots pines (Pinus sylvestris L.) from Southern Finland. Two systems of simultaneous equations were constructed, one without the crown ratio and the other with the crown ratio as an exogenous variable. The endogenous variables consisted of 24 relative-height diameters and the height of the tree. The parameters of the model were derived by the ordinary least squares method.

In most applications, the height of the tree was exogenised. The logarithmically linear relationships between the relative-height diameters were utilized in the solution algorithm. The algorithm included both standard matrix operations and an iterative part in which the taper curve was fitted to any measured diameters by the natural cubic spline interpolation formula.

The models were applied to the derivation of taper curves, stem volumes, timber assortment percentages, and stem values. An experiment was also made to derive diameter and height increments from the taper curve model.

The reliability of the models was tested on the original data.

The PDF includes a summary in Finnish.

  • Kilkki, ORCID ID:E-mail:
  • Varmola, ORCID ID:E-mail:

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