Fig. 1. Location of the study site: Lamto Scientific Reserve (in solid red circle), in Côte d’Ivoire. View larger in new window/tab.

Fig. 2. Distribution of the root/shoot biomass ratio (RSR) according to its growth form. In Panel A, species are pooled according to their growth form; specific values are shown in panel B. The different box colors in panel B correspond to different growth forms. The lower-case letters next to box plots indicate, when different, groups of significantly different values at the 95% threshold according to Student’s t-test. At intraspecific level (panel B), comparison of RSR between growth forms was done only for species including both growth forms (tree and shrub). Plant species: Ann.sen (Annona senegalensis); Bri.fer (Bridelia ferruginea); Cro.fer (Crossopteryx febrifuga); Cus.arb (Cussonia arborea); Pil.tho (Piliostigma thonningii).

Fig. 3. Distribution of the total above- and belowground biomass (AGB and BGB) and of the root/shoot biomass ratio (RSR) according to classes of basal diameter, number of stems and stem equivalent basal diameter for shrubs. The box colors and lower-case letters next to box plots indicate, when different, groups of significantly different values at the 95% threshold according to Tukey’s HSD post-hoc test by class of each variable (panels 3A–3E) or to Student’s t-test (panels 3G–3I). View larger in new window/tab.

Fig. 4. Fits of the best models predicting the above- and belowground biomass (AGB and BGB) of trees in the savanna of the Lamto Scientific Reserve: A) Fit of the best model predicting AGB in trees; B) Fit of the best model predicting BGB in trees. AGB and BGB are well predicted from the variable w (g cm^–1 m) = ρD_b²H, where D_b (cm) and H (m) represent the stem basal diameter and the stem total height, respectively; ρ (g cm^–3) is the woody specific density. Tree species are shown with different symbols. View larger in new window/tab.

Fig. 5. Variation of the aboveground biomass (AGB) and belowground biomass (BGB) of shrubs according to the variable w = ρD_b²H and the total number of stems (n). In the term ρD_b²H, ρ (g cm^–3) is the woody specific density and the term ρD_b²H corresponds to the sum of d_i²h_i (i = 1…n) of the n stems (with d_i = basal diameter in cm and h_i = total height of each stem in m). The different symbols and color of data points correspond to the different shrub species, and the size of points is proportional to log(n). View larger in new window/tab.

Fig. 6. Relationships between the aboveground biomass (AGB) and aboveground volume (D_b²H) for: A) 41 Crossopteryx febrifuga trees and B) 44 Bridelia ferruginea trees. The black dots correspond to data measured in Lamto savannas, while the red dots represent the measured data in Ifo et al. (2018) study. The Ifo et al. data used here were extracted from the figure 4a of their study showing a plot of the aboveground biomass versus wood density times tree height times square diameter at the base for 88 trees from five species measured in the savannas of the Plateau Batéké in Congo. We extracted only data related to Crossopteryx febrifuga and Bridelia ferruginea (16 trees and 19 trees respectively); and D_b²H were inferred from ρD_b²H values.