Table 3. Pairwise partial correlations (controlling for the effect of DBH) among wood characteristics in control (C) and humidified (H) plots, bold indicates significant (p < 0.05) relations.
Wood characteristic	Tree species	Cellulose		Lignin		Hemicellulose		[N]		[P]		[K]		Calorific value		Density
		C	H	C	H	C	H	C	H	C	H	C	H	C	H	C	H
Ash content	Aspen	–0.26	–0.71	–0.10	0.58	–0.13	0.10	0.29	0.75	0.25	0.86	0.10	0.76	0.16	–0.07	–0.12	–0.05
	Birch	–0.20	–0.22	0.35	0.37	0.09	0.44	0.28	0.50	0.67	0.77	0.85	0.80	0.28	0.30	0.24	0.34
Density	Aspen	–0.03	0.26	0.48	–0.12	0.04	–0.21	0.35	–0.30	0.34	–0.10	0.10	0.08	0.29	–0.37
	Birch	0.15	0.05	0.14	–0.03	–0.02	0.18	–0.23	0.49	0.11	0.40	0.31	0.39	0.20	0.05
Calorific value	Aspen	0.32	–0.42	0.25	–0.06	0.01	0.50	0.32	0.09	0.69	–0.13	0.06	–0.22
	Birch	–0.30	–0.12	0.76	0.62	–0.16	–0.20	–0.02	–0.05	0.08	0.01	0.06	0.30
[K]	Aspen	0.02	–0.54	0.35	0.51	–0.39	0.19	–0.11	0.66	0.01	0.85
	Birch	0.04	0.03	0.20	0.31	0.03	0.42	0.00	0.30	0.48	0.77
[P]	Aspen	0.24	–0.66	0.28	0.58	–0.21	0.08	0.54	0.83
	Birch	–0.16	–0.26	0.14	0.26	–0.05	0.43	0.39	0.65
[N]	Aspen	–0.23	–0.73	0.28	0.55	0.15	0.24
	Birch	–0.50	–0.36	–0.08	–0.05	0.25	0.27
Hemicellulose	Aspen	–0.16	–0.47	–0.24	–0.17
	Birch	–0.55	–0.45	–0.31	–0.15
Lignin	Aspen	–0.32	–0.65
	Birch	–0.01	–0.37