Comparison of model forms for estimating stem taper and volume in the primary conifer species of the North American Acadian Region

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Table III

Absolute mean bias (MAB), root mean square error (RMSE) and mean percentage of bias (MPB) of diameter inside bark for balsam fir, red spruce, and white pine.

	Balsam fir			Red spruce			White pine
Model
	MAB (cm)	RMSE	MPB (%)	MAB (cm)	RMSE	MPB (%)	MAB (cm)	RMSE	MPB (%)
Max and Burkhart (1976)	0.5319	0.8007	5.1889	0.5922	0.9294	5.5515	1.3647	1.9219	6.7420
Kozak (2004) Model 01	0.6883	0.9602	6.7140	0.8704	1.2052	8.1600	1.6792	2.2257	8.2959
Kozak (2004) Model 02	0.5042	0.7620	4.9184	0.5375	0.8179	5.0392	1.1564	1.6546	5.7128
Bi (2000)	0.4954	0.7587	4.8322	0.5384	0.8254	5.0472	1.1937	1.7213	5.8971
Zakrzewski (1999)	0.5104	0.7706	4.9787	0.6220	0.9363	5.8312	1.2974	1.9166	6.4095
Valentine and Gregoire (2001)	0.4801	0.7443	4.6830	0.5725	0.8581	5.3667	1.2800	1.8112	6.3235
Sharma and Zhang (2004)	0.5403	0.8120	5.2703	0.6292	0.9649	5.8982	1.3195	1.8292	6.5189
Sharma and Parton (2009)	0.5437	0.8497	5.3040	0.6245	1.0120	5.8544	1.3342	1.8863	6.5914
Clark et al. (1991) I	0.5229	0.7505	5.1003	0.5809	0.8517	5.4454	1.4205	2.0432	7.0176
Clark et al. (1991) II	0.6417	0.8730	6.2595	0.7216	0.9932	6.7647	1.6174	2.2108	7.9907
Fang et al. (2000)	0.5521	0.8129	5.3852	0.6177	0.9283	5.7907	1.3454	1.8623	6.6469
Geometric mean	0.4742	0.7196	4.6257	0.5269	0.8066	4.9393	1.1468	1.6315	5.6657

Clark et al. (1991) I: upper stem diameters at 5.27 m were obtained by linear interpolation. Clark et al. (1991) II: upper stem diameters at 5.27 m were predicted based on the regression form presented in Clark et al. (1991).