Table 4. Validation accuracy assessment of the biophysical forest attributes (BFA) estimates.
S	BFA	NEW approach						REUSE approach						FORECAST approach
		MPD	RMSE	RMSE%	λ0	λ1	σεem	MPD	RMSE	RMSE%	λ0	λ1	σεem	MPD	RMSE	RMSE%	λ0	λ1	σεem
S1	Ho	0.5ns	0.9	5	–1.1	1.03	0.8	0.4ns	0.8	4	4.6	0.73	0.7	1.4	1.5	8	4.4a	0.68b	0.4
	HL	0.9	1.0	6	1.6	0.84	0.4	0.5	0.7	4	1.0	0.90	0.4	1.7	1.8	12	2.8	0.71	0.5
	N	–439.3	471.4	38	431.8	1.01	179.2	–769.3	793.6	63	851.3a	0.93	203.6	–865.6	913.6	73	389.5	1.38	281.8
	G	–2.0	2.9	11	5.0	0.88	2.2	–1.4ns	3.9	15	1.7	0.99	3.9	–6.2	6.9	27	7.7	0.94	3.1
	V	–10.8ns	26.4	14	1.3	1.05	25.2	15.6ns	36.1	19	17.3	0.83	33.3	–38.3	49.0	25	42.8	0.98	32.0
	AGB	–6.7ns	14.7	12	6.3	1.00	13.7	17.4	23.7	19	–1.6	0.87	16.5	–17.5	21.7	17	20.0	0.98	13.4
S2	Ho	0.3ns	0.8	4	3.1a	0.81b	0.5	–0.1ns	1.0	5	4.7a	0.75b	0.6	–0.1ns	1.4	8	7.6a	0.58b	0.6
	HL	–0.2ns	0.7	4	2.2	0.87	0.6	–0.4	0.7	4	2.3a	0.88	0.5	–0.1ns	0.6	4	3.0a	0.82b	0.4
	N	7.2ns	116.6	18	121.8	0.80b	101.8	76.1ns	164.4	26	150.1a	0.64b	99.4	50.2ns	171.9	27	254.1a	0.52b	74.8
	G	–1.4ns	3.9	17	4.3	0.87	3.6	1.4ns	3.6	16	5.8a	0.69b	1.7	–2.4	4.2	19	8.5a	0.73b	2.6
	V	–19.9	32.6	18	38.1a	0.90	25.1	25.9	40.5	23	29.7a	0.69b	14.8	–20.4	33.3	19	53.2a	0.82b	21.4
	AGB	–12.8	23.2	21	22.5	0.91	19.4	25.5	33.4	31	12.6a	0.65b	9.0	–16.2	22.9	21	21.6	0.95	16.5
S3	Ho	0.1ns	0.8	4	3.3a	0.85b	0.7	–1.7	1.9	8	7.6a	0.74b	0.6	0.9	1.2	5	2.7a	0.84b	0.6
	HL	0.7	0.9	5	2.3a	0.86b	0.5	0.0ns	0.8	4	4.5a	0.78b	0.4	0.9	1.2	6	–0.1	0.96	0.7
	N	–52.0ns	171.1	22	158.6	0.86	163.2	39.1ns	163.2	21	362.2a	0.47b	104.5	–184.5	261.4	34	329.2a	0.81	183.9
	G	–1.7ns	4.5	15	4.6	0.91	4.2	4.3	6.3	20	3.8	0.73	4.2	–5.5	7.3	24	8.8	0.89	4.9
	V	–13.5ns	38.5	13	12.5	1.00	36.8	33.0	56.2	19	57.5a	0.70b	36.3	–42.6	73.5	25	35.0	1.03	61.1
	AGB	–5.0ns	21.3	13	20.5	0.91	20.6	20.9	30.9	18	23.6	0.74b	18.9	–24.5	41.0	24	42.2	0.90	33.1
S = Stratum. S1 = Young forest, S2 = Mature forest with Site index ≤ 11 m, S3 = Mature forest with Site index > 11 m. Biophysical forest attributes; Ho = Dominant height (m), HL = Lorey’s mean height (m), N = Stem number (ha–1), G = Basal area (m2 ha–1), V = Volume (m3 ha–1), AGB = Aboveground biomass (Mg ha–1). MPD = Mean predictor difference.­ RMSE = Root mean square error. RMSE% = relative RMSE. λ0, λ1, σεem = parameters from the error model equation. ns = Not statistically significant different from zero (p-value > 0.05). a rejected null hypothesis λ0 = 0. b rejected null hypothesis λ1 = 1 (based on t-tests Persson and Ståhl (2020))