Bark Thickness Equations for Mixed-Conifer Forest Type in Klamath and Sierra Nevada Mountains of California

Table 2

Comparison of bark thickness (BT; mm) as a function of DBH (cm) across latitudinal gradient (north, central, and south) and among crown classes (dominant, codominant, intermediate, and suppressed) for red fir (ABMA) and white fir (ABCO) at Klamath National Forest (KNF), Tahoe National Forest (TNF), and Sequoia National Forest (SNF). Coefficients and fit statistics for region and crown class dummy variable (d) in nonlinear regression.

Species	Region/crown class	Coefficient (d)	s.e.	Appr. 95% confidence limits
				Lower	Upper
ABMA ()
(RMSE = 6.22 mm)	North (KNF)	0.875	0.032	0.812	0.938
	Central (TNF)	0.941	0.031	0.880	1.003
	South (SNF)	0.917	0.030	0.858	0.976
(RMSE = 6.75 mm)	Dominant	0.964	0.042	0.881	1.047
	Codominant	0.973	0.051	0.872	1.074
	Intermediate	1.012	0.059	0.896	1.128
	Suppressed	1.041	0.068	0.906	1.176
ABCO ()
(RMSE = 6.15 mm)	North (KNF)	0.856	0.056	0.745	0.967
	Central (TNF)	0.888	0.029	0.831	0.945
	South (SNF)	0.865	0.028	0.810	0.921
(RMSE = 6.20 mm)	Dominant	0.924	0.036	0.853	0.995
	Codominant	0.947	0.043	0.861	1.033
	Intermediate	0.964	0.051	0.863	1.065
	Suppressed	0.996	0.060	0.877	1.116