Climate change-associated trends in biomass dynamics are consistent across soil drainage classes in western boreal forests of Canada

Forest Ecosystems

Table 1 Growth, mortality, and net biomass change associated with drainage class, forest age, and calendar year

Fixed effects	Sum of squares	df	F	P
Biomass gain from growth (Mg ha ⁻¹ year ⁻¹ )
D	0.80	2, 1466.1	2.41	0.090
f(A)	12.33	1, 1441.8	73.97	<0.001
Y	0.96	1, 4019.7	5.75	0.017
D × f(A)	0.01	2, 1546.8	0.02	0.976
D × Y	0.86	2, 4029.4	2.58	0.076
f(A) × Y	0.49	1, 3444.6	2.96	0.085
Biomass loss from mortality (Mg ha ⁻¹ year ⁻¹ )
D	14.77	2, 1713.4	6.39	0.002
f(A)	43.72	1, 1615.1	37.83	<0.001
Y	21.45	1, 3898.2	18.56	<0.001
D × f(A)	20.86	2, 1716.9	9.02	<0.001
D × Y	3.61	2, 3933.1	1.56	0.210
f(A) × Y	0.66	1, 3588.3	0.57	0.450
Net biomass change (Mg ha ⁻¹ year ⁻¹ )
D	11.56	2, 1804.6	4.06	0.017
f(A)	143.50	1, 1643.9	100.89	<0.001
Y	34.16	1, 3854.9	24.02	<0.001
D × f(A)	30.33	2, 1729.9	10.66	<0.001
D × Y	8.38	2, 3901.1	2.95	0.053
f(A) × Y	0.19	1, 3646	0.13	0.714

Forest age is logarithmically transformed (lnFA) and calendar year is represented by Year. Linear mixed-effects model fit tests used Satterthwaite approximations of degrees of freedom