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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 0.29ns ±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 –2.11ns ±1.14 0.56*±0.24 0.78ns ±0.65 85.48 0.540 0.474 25.48 1.157
D202×H; CD –2.37ns ±1.28 0.54ns ±0.24 0.90ns ±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 –0.32ns±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 1.08ns ±0.49 94.41 0.413 0.362 18.46 1.089
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 –0.53ns ±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 0.74ns ±0.46 91.93 0.384 0.336 16.58 1.076
D202×H; CD –3.03*±0.97 0.51*±0.19 0.93ns ±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 –0.97ns ±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 –0.17ns ±0.57 95.02 0.320 0.281 11.88 1.053
D202×H; CD –5.06**±0.89 1.05**±0.21 –0.16ns ±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 1.23ns ±0.65 95.12 0.367 0.322 15.45 1.069
D202×H; CD –4.53**±1.02 0.73*±0.24 1.31ns ±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 0.47ns ±0.24 1.30ns ±0.71 90.62 0.402 0.353 17.79 1.084
D202×H; CD –3.99**±1.06 0.46ns ±0.25 1.33ns ±0.74 90.25 0.410 0.359 18.29 1.088
D202×H; CD –3.82***±0.52 0.84***±0.12 0.76ns ±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 –0.74ns ±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 –0.41ns ±0.66 89.44 0.348 0.301 13.28 1.062
D202×H; CD –6.56**±1.44 1.22**±0.28 –0.30ns ±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 –0.63ns ±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
D202×H; CD –4.13**±1.19 0.74*±0.23 1.15ns ±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 1.05ns ±0.73 82.26 0.384 0.333 15.65 1.077
D202×H; CD –3.98*±1.57 0.45ns ±0.30 1.27ns ±0.77 79.97 0.408 0.354 17.11 1.087
Models selected as most appropriate are indicated in bold.
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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.
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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.

4a

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.

4b

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.

4c

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.

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