Improved allometric equations for tree aboveground biomass estimation in tropical dipterocarp forests of Kalimantan, Indonesia

Forest Ecosystems

Table 2 The parameter estimates and indicators of model fit from new AGB equations

Model ID	Equations	Parameter estimates				n	Adj.r ²	RMSE (kg)	AICc
Model ID	Equations	a	b	c	d	n	Adj.r ²	RMSE (kg)	AICc
D 1	0.125 D ^2.533	0.125 (0.033)	2.533 (0.062)			108	0.821	3215	2061
D2	Exp (−2.845 + 2.726 (Ln D) –0.094 (Ln D)² – 0.271 (Ln D)³) × 1.071	−2.845 (0.479)	2.726 (0.122)	−0.094 (0.104)	−0.271 (0.141)	108	0.810	3303	2061
DH 3	0.068 D ^2.268 H ^0.483	0.068 (0.027)	2.268 (0.215)	0.483 (0.200)		108	0.813	3281	2053
DH4	0.041 (D ² H)^0.986	0.041 (0.013)	0.986 (0.024)			108	0.804	3358	2064
DĤ 5	0.086D ^2.388 Ĥ ^0.326	0.086 (0.027)	2.388 (0.084)	0.326 (0.132)		108	0.823	3191	2059
DĤ6	0.05 (D ² Ĥ)^1.011	0.050 (0.016)	1.011 (0.027)			108	0.798	3409	2068
DG7	0.236D ^2.5 G ^1.079	0.236 (0.042)	2.500 (0.040)	1.079 (1.079)		108	0.918	2180	1971
DG 8	0.277 (D ² G)^1.238	0.277 (0.042)	1.238 (0.019)			108	0.924	2095	1963
*DGH* 9	0.071 (D ² GH)^0.973	0.071 (0.014)	0.973 (0.016)			108	0.909	2287	1981
*DGĤ* 10	0.093 (D ² GĤ)^0.994	0.093 (0.021)	0.994 (0.020)			108	0.895	2452	1997

Correction factors had been incorporated into the equations. The models presented in bold are the best equations from each model type. Values in parentheses are the standard errors