Difference between revisions of "Tree age functions"

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(TODO: Add reference)
 
(TODO: Add reference)
  
==Documents==
+
==Documents for download==
 
[[Media:AgeFuncElfving2003.pdf | Heureka model documentation for Elfving 2003 age functions (In Swedish)]]
 
[[Media:AgeFuncElfving2003.pdf | Heureka model documentation for Elfving 2003 age functions (In Swedish)]]
  
 
==Plugin==
 
==Plugin==
 
A custom age function can be used by implementing interface ITreeAge for establised stands. For young stands, you cannot supply a custom age function, since it is currently an internal function in the young stand growth model.
 
A custom age function can be used by implementing interface ITreeAge for establised stands. For young stands, you cannot supply a custom age function, since it is currently an internal function in the young stand growth model.

Revision as of 12:59, 10 May 2020

For trees that have no registered age, a calculated tree age is assigned with functions that include for example mean age, site index, tree diameter, tree species and diameter ratio to largest tree as explanatory variables.

Selection of age function in control table Production Model

You select the age function to use in control table Production Model, under "Age Model". If you have a custom age function (see Plugin below), it will be listed.

References

Default function "Elfving" for established stands

Elfving, B. 2003. Ålderstilldelning till enskilda träd i skogliga tillväxtprognoser. Arbetsrapport 182, Inst f skogsskötsel. In Swedish with English summary.

Age assigment in young stands

Nyström, K. and Söderberg, U. 1987. Tillväxtberäkningen för ungskog i HUGIN-systemet. En kontroll med data från återinventerade ungskogsytor. SLU, Institutionen för skogsskötsel. Arbetsrapport nr 18. ISSN 0281-7292. (In Swedish). Reproduced on page 10 in Heureka_prognossystem_(Elfving_rapportutkast).pdf

Age function for non-productive forest

If you set up a control category for non-pruductive forest, there is function alternative labelled "Low Production Nystrom" that you should use. (TODO: Add reference)

Documents for download

Heureka model documentation for Elfving 2003 age functions (In Swedish)

Plugin

A custom age function can be used by implementing interface ITreeAge for establised stands. For young stands, you cannot supply a custom age function, since it is currently an internal function in the young stand growth model.