How much timber from Norway spruce (Picea abies L.) is left on the harvesting site as treetops? A study on scaling and grading yields of harvesters

Table 3 The description of the linear mixed model, which shows the effects of the stem diameter class and harvester used on the share of losses or surpluses of volume of timber compared to the full stem volume

Model dimension dependent on variables losses and surpluses
		Number of levels	Covariance structure	Number of parameters
Fixed effects	Intercept	1		1
Fixed effects	Diameter class*	13		12
Random effects	Harvester type	3	Variance Components	1
Residual				1
Total		17		15
Information criterion dependent on variables losses and surpluses
Akaike’s Bayesian Criterion (BIC)^∆			-92,567.8
Coefficients of determination
Pseudo-R Square measures	Marginal⁰		0.054
Pseudo-R Square measures	Conditional⁰⁰		0.054
Type III tests of fixed effects dependent on variables losses and surpluses
Source	Numerator df	Denominator df	F-value	p-value
Intercept	1	10,996	187.7	< 0.001
Diameter class	12	10,996	52.0	< 0.001

*The stem diameter class is the central value of a stem diameter interval at breast height, ^∆ statistical measure of the quality of the model, ⁰ the share of variance explained by the fixed effect, ⁰⁰ the share of variance explained by all effects

ISSN: 1297-966X