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

Forest Ecosystems

Table 3 Estimated parameters and fitting statistics obtained for the local 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	σ ² _u	σ ² _v	σ _uv	R ²	*RMSE*	*Bias*	*BIC*
Pinus species	(7)	ONLS	34.9600	0.0223	1.0148				0.73	2.95	0.004	8749.7
Pinus species	(10)	NLMIXED	28.6890	0.0357	1.1148	47.9289	0.0002	−0.0849	0.85	2.21	0.005	6461.0
Quercus species	(7)	ONLS	21.1250	0.0240	0.9666				0.48	3.03	0.005	4021.3
Quercus species	(11)	NLMIXED	16.2456	0.0317	0.9971	20.8757			0.71	2.25	0.014	2955.0
Other conifer species	(7)	ONLS	24.4720	0.0094*	0.6691				0.69	1.62	0.002	197.1
Other conifer species	(11)	NLMIXED	134.2700	0.0004	0.6062	115.6000			0.75	1.46	−0.013	170.8
Other broadleaf species	(7)	ONLS	24.8375*	0.0085*	0.7489				0.66	1.35	−0.002	197.8
Other broadleaf species	(11)	NLMIXED	94.3893	0.0005	0.6086	130.9100			0.79	1.07	−0.015	70.0

ONLS = fitted by ordinary least squares, NLMIXED = fitted by non-linear mixed effects; *estimated parameters not significant at the 0.05 level.