Aboveground biomass equations for sustainable production of fuelwood in a native dry tropical afro-montane forest of Ethiopia

Table 4 Simultaneous fit of biomass models for the studied species

Species	Compartment	MRES	RMSE	R ² _adj	Selected model	Estimated parameters	Pr > \|t\|
Allophyllus abyssinicus	Above	0.01	10.27	0.84	W _above = β × (d × h)	0.3937	<.0001
Olea europaea ssp. cuspidata	Stem	0.72	12.01	0.93	W _stem = β × (d ² × h)	0.02746	<0.0001
	Br27	−0.53	4.47	0.79	W _Br27 = (β × d ²) + (λ × h)	0.05744	<.0001
	Br27	−0.53	4.47	0.79	W _Br27 = (β × d ²) + (λ × h)	0.6856	0.0008
	Br2	0.09	5.29	0.69	W _Br2 = β × (d ² × h)	0.006584	<.0001
	Above	0.27	12.03	0.96	W _above = ∑W _i
Olinia rochetiana	Stem	0.25	35.06	0.76	W _stem = β × (d × h)	0.3990	<.0001
	Crown	1.31	14.41	0.58	W _crown = (β × d ²) + λ × (d ² × h)	0.4550	<.0001
	Crown	1.31	14.41	0.58	W _crown = (β × d ²) + λ × (d ² × h)	−0.02163	<.0001
	Above	1.56	33.38	0.85	W _above = ∑W _i
Rhus glutinosa	Stem	3.34	10.57	0.79	W _stem = β × (d ² × h)	0.01604	<.0001
	Crown	−1.24	6.28	0.68	W _crown = (β × d ²) + (λ × h)	0.04867	0.0017
	Crown	−1.24	6.28	0.68	W _crown = (β × d ²) + (λ × h)	1.3033	<.0001
	Above	2.11	11.11	0.88	W _above = ∑W _i
Scolopia theifolia	Stem	1.52	6.94	0.75	W _stem = β × (d ² × h)	0.02107	<.0001
	Crown	0.65	7.67	0.55	W _crown = β × (d × h)	0.4253	<.0001
	Above	2.17	11.04	0.79	W _above = ∑W _i

Stem (kg) stem biomass, Br27 (kg) biomass of thick branches (diameter between 2 and 7 cm), Br2 (kg) biomass of thin branches (diameter < 2 cm) plus foliage, Crown (kg) biomass of branches plus foliage, Above (kg) stem + thick branches (2–7) + thin branches + leaves biomass or stem + crown biomass, W _i (kg) biomass weight of the different compartments, d dbh (cm), h tree height (m), β, λ parameters of the models, MRES mean residual (kg), RMSE root mean square error (kg), R ² _adj adjusted coefficient of determination

ISSN: 1297-966X