Development and evaluation of an individual tree growth and yield model for the mixed species forest of the Adirondacks Region of New York, USA

Forest Ecosystems

Table 4 Results of the equivalence test of the Northeast (NE) Variant of FVS for total height (m) and the parameter estimates and fit statistics for Eq. [1]. Mean bias (MB; observed – predicted) and root mean square error (RMSE) were computed using the fixed effects only. Both mean difference and MB were computed as observed – predicted. The null hypothesis for the equivalence test is that μ ₁ ≠ μ ₂

SPP^a	N	FVS–NE		Equation [1]
SPP^a	N	Mean ± SE difference (m)	Result of equivalence test	b ₁₀	b ₁₁	b ₁₂	b ₁₃	b ₁₄	MB (m)	RMSE (m)
AB	928	–0.45 ± 0.11	rejected	33.6020	0.0201	1.0584	–0.0498	–0.0889	0.0009	2.9021
AS	263	3.33 ± 0.21	not rejected	42.0612	0.0093	0.7372	–0.0916	–	0.0011	2.8813
BC	212	2.00 ± 0.26	rejected	30.2327	0.0243	1.4215	–0.2522	–	0.0814	2.6475
BF	131	1.33 ± 0.27	rejected	42.0696	0.0121	0.8860	–0.0720	–	0.0011	2.8830
EH	635	–1.43 ± 0.12	rejected	48.0279	0.0117	1.2979	–0.0981	–0.0429	–0.4499	2.7909
OH	309	0.23 ± 0.22	rejected	35.4457	0.0242	1.0128	–	–0.0755	0.1742	3.7033
OS	440	2.82 ± 0.22	not rejected	26.1875	0.0819	3.5310	–	–0.3375	0.7962	4.5155
RM	827	2.49 ± 0.11	rejected	29.9463	0.0331	1.2740	–0.0892	–0.0878	–0.0496	2.7841
RN	313	4.19 ± 0.16	not rejected	29.9419	0.0752	3.5272	–	–0.5136	–0.4386	2.7722
SM	1672	2.21 ± 0.08	rejected	38.0384	0.0211	1.0325	–0.0544	–0.0639	–1.0922	2.9732
SP	498	0.36 ± 0.13	rejected	42.3324	0.0217	1.4738	–0.0453	–0.1076	–0.4566	2.5105
WP	340	1.85 ± 0.20	rejected	37.7213	0.0289	1.8887	–0.1368	–0.1392	0.3715	3.1214
YB	989	0.58 ± 0.10	rejected	29.5755	0.0286	1.0028	–0.0299	–0.0886	0.0001	2.7534

^a SPP Species are AB American beech, AS ash, BF balsam fir, EH eastern hemlock, OH other hardwoods, OS other softwoods, RM red maple, RN red pine, SM sugar maple, SP spruce, WP white pine, and YB yellow birch