TABLE 1.

(a) Variance components of the species, site and year level within stem growth phenology and activity, given in standard deviation and percent of variation, derived from mixed effect models with GRO_start, GRO_end, GRO_length, daily growth rate or N days_growth as dependent variable, and year, site and species as nested random effects. (b) Approximation of the spatial variability of growth phenology and activity was tested by GAM of median values of the respective variables per site against mean annual precipitation (MAP), mean annual temperature (MAT) and elevation. Given is the sign of the relationship, dAIC of the model against the lowest AIC of all models, the adjusted R ² of the model and the p‐value

	(a) Variance partitioning of growth phenology and activity				(b) Approximation of spatial variability of growth phenology and activity
	Random factor	Std. Dev	%	p‐value	Explaining variable	Sign	dAIC	Adj. R ²	p‐value
GRO_start	Species	11.5	25.5	***	MAP		45	—	n.s.
	Site	12.2	27.1	***	MAT	−	0	0.64	***
	Year	9.1	20.2	***	Elevation	+	16	0.49	***
	Residual	12.1	27.0
GRO_end	Species	7.0	10.2	n.s.	MAP	+	9	0.18	*
	Site	12.5	18.2	***	MAT	−	0	0.33	**
	Year	18.4	26.7	***	Elevation		14	—	n.s.
	Residual	30.8	44.8
GRO_length	Species	4.5	6.5	n.s.	MAP		0	—	n.s.
	Site	14.7	21.4	***	MAT		1	—	n.s.
	Year	15.8	23.0	***	Elevation		0	—	n.s.
	Residual	33.5	49.0
Daily growth rate	Species	4.5	22.5	***	MAP		17	—	n.s.
	Site	4.0	19.8	***	MAT	−	0	0.33	***
	Year	2.6	12.8	n.s.	Elevation	+	8	0.22	*
	Residual	9.0	44.9
N days_growth	Species	11.7	22.1	***	MAP	+	0	0.28	**
	Site	15.3	28.9	***	MAT		14	—	n.s.
	Year	11.8	22.3	n.s.	Elevation		12	—	n.s.
	Residual	26.8	26.8

Significance is given as ***p < 0.001, **p < 0.01, p < 0.05, ‘n.s.’ not significant. See also Figure S7.