Local and generalized height-diameter models with random parameters for mixed, uneven-aged forests in Northwestern Durango, Mexico

Forest Ecosystems

Table 4 Estimated parameters and fitting statistics obtained for the generalized model with and without mixed effects for the groups of species considered

Species	Equation	Fitting method	Parameters						Statistics
Species	Equation	Fitting method	b ₀	b ₁	b ₂	b ₃	b ₄	σ ² _u	R ²	*RMSE*	*Bias*	*BIC*
Pinus species	(8)	ONLS	4.4250	0.6125	0.0392	1.5073	−0.0847		0.82	2.41	−0.013	7141.6
Pinus species	(12)	NLMIXED	4.1798	0.6330	0.0398	1.8370	−0.1428	0.1150	0.84	2.29	−0.011	6730.5
Quercus species	(8)	ONLS	1.1200	0.9694	0.0363	2.8325	−0.2697		0.66	2.45	0.031	3267.4
Quercus species	(13)	NLMIXED	1.0046	0.9804	0.0375	2.5189	−0.2482	0.0017	0.72	2.23	−0.019	2941.0
Other conifer species	(9)	ONLS	1.2830	0.0002	−0.1036				0.64	1.74	0.118	224.5
Other conifer species	(14)	NLMIXED	1.2923	0.0231	−0.1038			0.0018	0.74	1.49	0.029	177.1
Other broadleaf species	(9)	ONLS	1.3120	0.0001	−0.1634				0.63	1.41	−0.011	226.0
Other broadleaf species	(15)	NLMIXED	1.1986	0.0017	−0.1352			0.0027	0.79	1.06	−0.094	63.8

ONLS = fitted by ordinary least squares, NLMIXED = fitted by non-linear mixed effects.