Leaf harvesting intensity alters growth and functional traits of baobab (<i>Adansonia digitata</i>) in semi-arid West African systems

Sissou Zakari; Sékaro Amamath Boukari; Pierre Gbènoukpo Tovihoudji; Mouiz Wal-Ikram Aremou Yessoufou; Gbadamassi Gouvidé Olawolé Dossa; Pierre Bienvenu Irénikatché Akponikpè; Sissou Zakari; Sékaro Amamath Boukari; Pierre Gbènoukpo Tovihoudji; Mouiz Wal-Ikram Aremou Yessoufou; Gbadamassi Gouvidé Olawolé Dossa; Pierre Bienvenu Irénikatché Akponikpè

doi:10.48130/cas-0026-0002

Figure 1.

(a) Location of the study site, and (b) study design in the commune of Parakou, Benin. Green stars are Adansonia digitata seedlings. In each plot, 50% of leaves were harvested on two random trees (I50), 75% on the other two random trees (I50), and the remaining two trees were not harvested. Three plots were considered as a subblock that was replicated three times.

Figure 2.

Variation of day after transplanting soil water content under (a) A. digitata leaves harvesting intensity, and (b) soil radial distance from plant. I50 is 50% leaves harvesting, and I75 is 75% harvesting intensity. Rd₀, Rd₁₀, and Rd₂₀ represent 0, 10, and 20 cm radial distance from the seedling stem, respectively.

Figure 3.

Variation of day after transplanting (a) number of A. digitata seedlings leaves, (b) stem diameter at two heights, and (c) seedlings height under leaves harvesting intensity. I50 is 50% leaves harvesting, and I75 is 75% harvesting intensity.

Figure 4.

Changes in the day after transplanting A. digitata seedling leaves, fresh and dry biomass yields under leaf harvesting intensity. I50 is 50% leaves harvesting, and I75 is 75% harvesting intensity.

Figure 5.

(a)–(c) Correlation, and (d)–(f) principal components analysis among soil water content, and A. digitata growth parameters and biomass yields using fI50, I75, and global data (I50 + I75). I50 and I75 are 50% and 75% leaf harvesting intensities, respectively. Swc: Soil water content; D: Stem diameter; N: number of leaves; FreshB: Fresh biomass; and DryB: Dry biomass. Axis 1 of the PCA separates growth-related variables from soil moisture.

Figure 6.

Structural equation model showing the underlying mechanism of soil water content, and A. digitata growth parameters and biomass yields under harvesting intensity. The thickness of the path equates to the strength of the path coefficient. Black and red arrows indicate positive and negative paths, respectively. Green color ellipse are response variables; blue color boxes represent the factor, and below each factor is shown its level and the baseline of comparison. The proportion of variation explained by the model (R²) is shown next to each endogenous variable. I50 and I75 are 50% and 75% leaves harvesting intensities, respectively. Asterisks associated to values are the level of significance of the p-value (*** p < 0.001; ** p < 0.01; and * p < 0.05). Chi square = 4.84, p-value = 0.564, degree of freedom (DF) = 6, RMSEA = 0.014, Comparative Fit Index (CFI) = 1.000. Swc: Soil water content; RdSwc: Radial soil water content.