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 4 The outcomes of one-way analysis of variance showing the effects of the stem diameter class on the share of losses or surpluses of volume of timber compared to the full stem volume

Effect	Degr. of freedom	Sums of squares	Mean square	F-value	p-value
Intercept	1	0.0024	0.0024	190	< 0.001
Factor – Diameter class*	12	0.0080	0.00067	52	< 0.001
Error	10,996	0.14	0.000013

* The stem diameter class is the central value of a stem diameter interval at breast height (e.g., stem diameter class 10 relates to diameters at breast height of 9.1 to 11.0 cm

ISSN: 1297-966X