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

Forest Ecosystems

Table 2 Relative 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 (% year ⁻¹ )
D	1.30	2, 1226.5	4.03	0.018
f(A)	27.54	1, 1404.2	170.78	<0.001
Y	4.16	1, 4200.9	25.78	<0.001
D × f(A)	3.57	2, 1558	11.07	<0.001
D × Y	9.45	2, 4183.5	29.31	<0.001
f(A) × Y	24.79	1, 3871.3	153.68	<0.001
Biomass loss from mortality (% year ⁻¹ )
D	3.69	2, 1717.4	3.35	0.035
f(A)	7.48	1, 1658.6	13.57	<0.001
Y	7.21	1, 3898.4	13.08	<0.001
D × f(A)	5.61	2, 1814.4	5.09	0.006
D × Y	0.61	2, 3899.3	0.55	0.578
f(A) × Y	2.65	1, 3729.5	4.80	0.029
Net biomass change (% year ⁻¹ )
D	17.35	2, 1393.2	11.02	<0.001
f(A)	136.93	1, 1341.1	173.96	<0.001
Y	27.00	1, 3794	34.30	<0.001
D × f(A)	16.51	2, 1484.8	10.49	<0.001
D × Y	17.84	2, 3794.3	11.33	<0.001
f(A) × Y	7.00	1, 3571.9	8.89	0.003

Forest age is the inverse of logarithmically transformed age (lnFA ⁻¹) and calendar year is represented by Year. Linear mixed-effects model fit tests used Satterthwaite approximations of degrees of freedom