Silva Fennica

Fig. 1. Location of the study area (Bolon, Tapoa-Boopo and Tiogo forests) in Burkina Faso. View larger in new window/tab.

Table 1. Biophysical characteristics of Bolon, Tapoa-Boopo and Tiogo forests (Guinko 1984).
Protected areas	Boulon	Tapoa-Boopo	Tiogo
Region	Cascades	Eastern	Central-West
Location	10°15´–10°22´N; 4°20´–4°38´W	12°10´–12°23´N; 0°58´–1°13´W	12°10´–12°25´N; 2°39´–2°54´W
Area (ha)	13 521.70	36 202.30	30 339
Climate	Sudanian	Sudano-Sahelian	Sudano-Sahelian
Annual rainfall (mm)	900–1100	600–900	600–900
Rainfall regime	Unimodal	Unimodal	Unimodal
Temperature range (°C)	17–36	25–33	25–35
Main vegetation	Dense dry forest, savannas	Tree and shrub savannas	Tree and shrub savannas

Table 2. Summary statistics of sample tree characteristics and biomass data. View in new window/tab.

Table 3. Allometric models developed for estimation of biomass of stem, branches and leaves of Diospyros mespiliformis in Burkina Faso. ln(β₀), β₁ and γ represent the intercept and regression coefficients of the models, and their respective standard errors. The indicators of performance for the models include the adjusted coefficient of determination (Adj.R²), residual standard error (RSE), root mean squared error (RMSE), Akaike information criterion (AIC) and correction factor (CF).
		Regression coefficients			Performance criteria
Equation	Predictors	ln(β₀)	β₁	γ	Adj.R²	RSE	RMSE	AIC	CF
Boulon (Sudanian zone)
Stem biomass
Eq(5)	DBH	–3.25^***±0.48	2.22^***±0.15		94.70	0.327	0.300	11.62	1.055
	D20	–4.27±0.48*	2.39±0.14*		96.02	0.283	0.260	07.89	1.041
	CD	0.29^ns ±0.53	2.14^***±0.31		79.85	0.637	0.586	28.98	1.225
Eq(6)	DBH²×H	–3.08^**±0.84	0.84^***±0.10		84.83	0.552	0.508	25.28	1.165
	DBH²×CD	–2.22***±0.49	0.76^***±0.06		92.76	0.382	0.351	15.68	1.076
	D20²×H	–3.68^**±0.96	0.87^***±0.11		83.61	0.574	0.528	26.29	1.179
	D20²×CD	–2.85^***±0.51	0.79^***±0.06		93.59	0.359	0.330	14.09	1.067
Eq(7)	DBH²×H; CD	–2.11^ns ±1.14	0.56^*±0.24	0.78^ns ±0.65	85.48	0.540	0.474	25.48	1.157
Eq(7)	D20²×H; CD	–2.37^ns ±1.28	0.54^ns ±0.24	0.90^ns ±0.62	85.17	0.546	0.479	25.75	1.161
Branch biomass
Eq(5)	DBH	–4.47^***±0.64	2.73^***±0.20		93.93	0.591	0.395	18.77	1.097
	D20	–5.58^***±0.81	2.89^***±0.24		92.37	0.482	0.444	21.76	1.123
	CD	–0.32^ns±0.50	2.76***±0.29		87.91	0.607	0.558	27.73	1.202
Eq(6)	DBH²×H	–4.62^***±0.72	1.07^***±0.09		92.49	0.478	0.440	21.55	1.121
	DBH2×CD	–3.32±0.50*	0.94±0.06*		95.03	0.389	0.358	16.18	1.079
	D20²×H	–5.32^***±0.95	1.10^***±0.11		89.42	0.568	0.522	26.00	1.175
	D20²×CD	–4.02^***±0.60	0.98^***±0.07		94.06	0.425	0.391	18.49	1.095
Eq(7)	DBH²×H; CD	–3.30^**±0.87	0.69^**±0.19	1.08^ns ±0.49	94.41	0.413	0.362	18.46	1.089
Eq(7)	D20²×H; CD	–3.36^*±1.08	0.62^*±0.21	1.34^*±0.52	93.00	0.462	0.405	21.39	1.112
Leaf biomass
Eq(5)	DBH	–3.71^***±0.58	2.09^***±0.18		91.65	0.390	0.359	16.26	1.079
	D20	–4.58^***±0.70	2.22^***±0.21		90.48	0.417	0.383	17.97	1.091
	CD	–0.53^ns ±0.43	2.10^***±0.25		84.94	0.524	0.482	23.92	1.147
Eq(6)	DBH²×H	–3.85^***±0.62	0.82^***±0.07		90.76	0.411	0.378	17.57	1.088
	DBH2×CD	–2.82±0.48*	0.72±0.06*		92.44	0.371	0.342	14.97	1.071
	D20²×H	–4.39^***±0.78	0.85^***±0.09		88.05	0.467	0.429	20.92	1.115
	D20²×CD	–3.37^***±0.55	0.75^***±0.06		91.73	0.389	0.357	16.14	1.078
Eq(7)	DBH²×H; CD	–2.95^**±0.81	0.56^**±0.17	0.74^ns ±0.46	91.93	0.384	0.336	16.58	1.076
Eq(7)	D20²×H; CD	–3.03^*±0.97	0.51^*±0.19	0.93^ns ±0.47	90.60	0.414	0.363	18.56	1.090
Tapoa-Boopo (Sahelo-Sudanian zone)
Stem biomass
Eq(5)	DBH	–3.89^***±0.63	2.39^***±0.20		92.19	0.401	0.369	16.96	1.084
	D20	–4.37^***±0.71	2.40^***±0.21		91.43	0.420	0.386	18.17	1.092
	CD	–0.97^ns ±0.64	2.77^***±0.38		81.58	0.616	0.567	28.12	1.209
Eq(6)	DBH2×H	–4.50±0.51*	0.99±0.06*		95.43	0.307	0.282	09.99	1.048
	DBH²×CD	–3.15^***±0.61	0.85^***±0.08		91.07	0.429	0.394	18.69	1.096
	D20²×H	–4.89^***±0.59	0.99^***±0.07		94.64	0.332	0.305	12.06	1.057
	D20²×CD	–3.48^***±0.67	0.85^***±0.08		90.33	0.446	0.410	19.73	1.104
Eq(7)	DBH²×H; CD	–4.66^***±0.74	1.05^***±0.19	–0.17^ns ±0.57	95.02	0.320	0.281	11.88	1.053
Eq(7)	D20²×H; CD	–5.06^**±0.89	1.05^**±0.21	–0.16^ns ±0.63	94.15	0.347	0.304	13.97	1.062
Branch biomass
Eq(5)	DBH	–4.99^***±0.49	2.83^***±0.16		96.39	0.316	0.291	10.78	1.051
	D20	–5.56^***±0.58	2.84^***±0.17		95.65	0.347	0.319	13.21	1.062
	CD	–1.68^*±0.54	3.36^***±0.32		90.15	0.522	0.480	23.83	1.146
Eq(6)	DBH²×H	–5.46^***±0.69	1.15^***±0.08		93.97	0.408	0.376	17.44	1.087
	DBH2×CD	–4.17±0.43*	1.02±0.05*		96.70	0.302	0.278	09.62	1.047
	D20²×H	–5.90^***±0.76	1.15^***±0.09		93.20	0.434	0.399	19.00	1.099
	D20²×CD	–4.56^***±0.50	1.02^***±0.06		95.96	0.334	0.307	12.23	1.057
Eq(7)	DBH²×H; CD	–4.34^***±0.85	0.76^***±0.22	1.23^ns ±0.65	95.12	0.367	0.322	15.45	1.069
Eq(7)	D20²×H; CD	–4.53^**±1.02	0.73^*±0.24	1.31^ns ±0.71	94.41	0.393	0.345	17.22	1.080
Leaf biomass
Eq(5)	DBH	–4.64^***±0.65	2.17^***±0.21		90.17	0.412	0.379	17.65	1.088
	D20	–5.09^***±0.70	2.18^***±0.21		89.93	0.417	0.383	17.95	1.091
	CD	–2.19^*±0.47	2.62^***±0.28		88.10	0.453	0.417	20.12	1.108
Eq(6)	DBH²×H	–5.02^***±0.74	0.88^***±0.109		88.63	0.443	0.407	19.53	1.103
	DBH2×CD	–4.04±0.55*	0.78±0.07*		91.60	0.381	0.350	15.59	1.075
	D20²×H	–5.38^***±0.79	0.88^***±0.09		88.29	0.449	0.413	19.92	1.106
	D20²×CD	–4.36^***±0.58	0.78^***±0.07		91.24	0.389	0.357	16.14	1.078
Eq(7)	DBH²×H; CD	–3.85^**±0.93	0.47^ns ±0.24	1.30^ns ±0.71	90.62	0.402	0.353	17.79	1.084
	D20²×H; CD	–3.99^**±1.06	0.46^ns ±0.25	1.33^ns ±0.74	90.25	0.410	0.359	18.29	1.088
	D20²×H; CD	–3.82^***±0.52	0.84^***±0.12	0.76^ns ±0.36	97.09	0.201	0.176	–0.285	1.020
Tiogo (Sahelo-Sudanian zone)
Stem biomass
Eq(5)	DBH	–5.11^***±0.91	2.75^***±0.28		89.44	0.348	0.318	12.54	1.062
	D20	–5.78^***±1.10	2.82^***±0.33		86.95	0.387	0.353	15.08	1.078
	CD	–0.74^ns ±0.97	2.49^***±0.54		64.93	0.634	0.579	26.94	1.223
Eq(6)	DBH2×H	–5.58±0.93*	1.09±0.11*		90.10	0.337	0.308	11.77	1.058
	DBH²×CD	–3.92^**±0.95	0.93^***±0.12		85.36	0.410	0.374	16.46	1.088
	D20²×H	–6.18^***±1.06	1.12^***±0.12		88.67	0.360	0.329	13.38	1.067
	D20²×CD	–4.37^***±1.07	0.95^***±0.13		83.71	0.432	0.395	17.74	1.098
Eq(7)	DBH²×H; CD	–6.02^***±1.20	1.23^***±0.25	–0.41^ns ±0.66	89.44	0.348	0.301	13.28	1.062
Eq(7)	D20²×H; CD	–6.56^**±1.44	1.22^**±0.28	–0.30^ns ±0.71	87.66	0.376	0.326	15.15	1.073
Branch biomass
Eq(5)	DBH	–4.58^***±0.85	2.80^***±0.27		90.93	0.326	0.298	10.99	1.055
	D20	–5.32^***±1.00	2.89^***±0.29		89.49	0.351	0.321	12.75	1.064
	CD	–0.63^ns ±0.66	2.83^***±0.37		84.16	0.431	0.394	17.68	1.097
Eq(6)	DBH²×H	–4.98^***±0.94	1.11^***±0.11		90.08	0.341	0.312	12.06	1.060
	DBH2×CD	–3.63±0.65*	0.98±0.08*		93.30	0.280	0.256	07.35	1.040
	D20²×H	–5.63^***±1.03	1.14^***±0.12		89.46	0.352	0.321	12.79	1.064
	D20²×CD	–4.13^***±0.73	1.00^***±0.09		92.50	0.297	0.271	08.69	1.045
Eq(7)	DBH²×H; CD	–3.77^***±1.04	0.73^***±0.22	1.10^*±0.57	92.19	0.303	0.262	09.92	1.047
Eq(7)	D20²×H; CD	–4.13^**±1.19	0.74^*±0.23	1.15^ns ±0.59	91.80	0.310	0.269	10.52	1.049
Leaf biomass
Eq(5)	DBH	–4.90^***±1.07	2.23^***±0.33		80.10	0.407	0.372	16.30	1.086
	D20	–5.31^**±1.31	2.25^***±0.38		74.64	0.459	0.419	19.19	1.111
	CD	–1.84^*±0.66	2.29^***±0.37		77.52	0.433	0.395	17.76	1.098
Eq(6)	DBH²×H	–5.27^***±1.11	0.89^***±0.13		80.36	0.405	0.369	16.14	1.085
	DBH2×CD	–4.18**±0.86	0.79±0.10*		83.41	0.372	0.339	14.11	1.072
	D20²×H	–5.64^**±1.30	0.89^***±0.15		76.53	0.442	0.404	18.28	1.103
	D20²×CD	–4.48^**±1.01	0.79^***±0.12		79.82	0.410	0.374	16.46	1.088
Eq(7)	DBH²×H; CD	–4.11^*±1.32	0.53^*±0.28	1.05^ns ±0.73	82.26	0.384	0.333	15.65	1.077
Eq(7)	D20²×H; CD	–3.98^*±1.57	0.45^ns ±0.30	1.27^ns ±0.77	79.97	0.408	0.354	17.11	1.087
Models selected as most appropriate are indicated in bold.

Fig. 2. Residuals and observed values versus predicted values of stem (SB), branch (BB) and leaf biomass (LB) for Boulon, Tapoa-Boopo and Tiogo forests, respectively. View larger in new window/tab.

Table 4. Site-specific allometric equations for estimating aboveground biomass of Diospyros mespiliformis in Burkina Faso. ln(β₀), β₁ and γ represent the intercept and regression coefficients of the models, and their respective standard errors. The indicators of performance for the models include the adjusted coefficient of determination (Adj.R²), residual standard error (RSE), root mean squared error (RMSE), Akaike information criterion (AIC) and correction factor (CF). View in new window/tab.

Fig. 3. Residuals and observed values versus predicted values of aboveground biomass (AGB) in Boulon, Tapoa-Boopo and Tiogo. View larger in new window/tab.

Fig. 4a. Comparison of models’ performances using the fitting dataset in Boulon. (left) Predicted and observed aboveground biomass values for the selected models. (right) Mean relative errors for the compared models across the observed aboveground biomass values. View larger in new window/tab.

Fig. 4b. Comparison of models’ performances using the fitting dataset in Tapoa-Boopo. (left) Predicted and observed aboveground biomass values for the selected models. (right) Mean relative errors for the compared models across the observed aboveground biomass values. View larger in new window/tab.

Fig. 4c. Comparison of models’ performances using the fitting dataset in Tiogo. (left) Predicted and observed aboveground biomass values for the selected models. (right) Mean relative errors for the compared models across the observed aboveground biomass values. View larger in new window/tab.

Fig. 5. Carbon content in Diospyros mespiliformis tree components (from 5 samples) in Boulon, Tapoa-Boopo and Tiogo forests.