Position, size, and spatial patterns of bark stripping wounds inflicted by red deer (Cervus elavus L.) on Norway spruce using generalized additive models in Austria

Table 3 Statistical parameters of the models for wound length, width, area, and relative wound width (width divided by stem circumference).

Model	*Adj. R*²	*AIC*	*RMSE*	Parametric terms		Smooth terms
Model	*Adj. R*²	*AIC*	*RMSE*	Term	p values	Term	p values	k'	*edf*
Length	0.255	31,642.73	5.45 cm	Intercept	< 2e–16 ***	Coordinates	< 2e–16 ***	463	41.66
Length	0.255	31,642.73	5.45 cm	w	< 2e–16 ***	DBH	6.92e–07 ***	49	3.08
Width	0.159	22,825.74	19.89 cm	Intercept	< 2e–16 ***	Coordinates	< 2e–16 ***	463	36.43
Width	0.159	22,825.74	19.89 cm	w	< 2e–16 ***	DBH	< 2e–16 ***	49	5.03
Area	0.190	53,121.72	498.89 cm²	Intercept	< 2e-16 ***	Coordinates	< 2e–16 ***	463	49.00
Area	0.190	53,121.72	498.89 cm²	w	< 2e–16 ***	DBH	< 2e–16 ***	45.52	4.33
Relative width	0.249	− 9382.06	0.0841	Intercept	< 2e–16 ***	Coordinates	< 2e–16 ***	463	36.14
Relative width	0.249	− 9382.06	0.0841	w	< 2e–16 ***	DBH	< 2e–16 ***	49	4.56

Adj. R² adjusted R²; AIC, Akaike information criterion (Akaike, 1973); RMSE, root mean square error; k’, maximum possible degrees of freedom for the term; edf, effective degrees of freedom

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