Tegnhammar_1992_adjusted_SI: Tegnhammars' correction for SI 1992

In Silviculturalist/forester: Forest Science and Forestry

Tegnhammars' correction for SI 1992

Description

Tegnhammar's dissertation investigated a trend in the site index curves for spruce in Sweden, possibly caused by stem sectioning of elderly trees that were suppressed in their youth; young planted forests are composed of better plant material; young forests have recieved a better start as a result of methods introduced during the 1920-1950's; older stands which were not suitable for SI estimation by height were measured in such a manner nonetheless; The risk of including hidden top breakages is larger for older trees; & the productivity has increased with time due to nitrogen deposition - younger trees have been affected for a longer period of their lifetime.

Usage

Tegnhammar_1992_adjusted_SI(SIH, dominant_age, latitude)

Arguments

SIH	Site index, metres.
dominant_age	arithmetic mean of the age at breast height of the dominant trees.
latitude	degrees

Details

This function corrects height development functions by Hägglund (1972, 1973) for the 'apparent' trend, an age bias, wherein the functions would indicate higher SIH in young forests as compared to older forests, even if the site index is the same.

Value

SIHjust, m.

Source

Tegnhammar, L. (1992) "Om skattningen av ståndortsindex för gran", eng:"On the estimation of site index for Norway spruce". Report 53. Dept. of Forest Survey. Swedish University of Agricultural Sciences. Umeå.p.14. ISSN 0348-0496

Silviculturalist/forester documentation built on April 20, 2024, 2:13 p.m.