Predicting stand age in managed forests using National Forest Inventory field data and airborne laser scanning

Forest Ecosystems

Table 5 Independent variables of the second stand age model

	Estimate	Standard error	t-value	P-value
Intercept	2.444	0.076	32.091	< 2e–16
f_b05	0.008	0.001	9.898	< 2e–16
l_b20	0.004	0.001	4.456	9.70e–06
mineral	−0.977	0.109	−8.937	< 2e–16
sqrt (l_max × north)	0.306	0.044	6.963	7.68e–12
sqrt (l_max × mineral)	0.170	0.028	6.124	1.52e–09
sqrt (l_max × low)	0.303	0.019	16.228	< 2e–16
l_max × site1	−0.018	0.003	−6.218	8.67e–10
l_max × site2	−0.019	0.002	−11.508	< 2e–16
l_max × site3	−0.009	0.001	−6.400	2.85e–10
f_b95 × Lapland	−0.012	0.002	−7.083	3.45e–12
l_avg × lat	1.37e–08	1.10e–09	12.460	< 2e–16
f_b05 × other	−0.006	0.001	−7.843	1.65e–14
l_b70 × meanD	0.0007	2.94e–05	22.907	< 2e–16
almost natural	0.222	0.038	5.787	1.08e–08
sqrt (l_max × Juva)	−0.035	0.007	−4.836	1.63e–06
f_b05 × Kuhmo	−0.004	0.001	−5.334	1.30e–07