Fig. 4

Effects of system and season on gas exchange parameters (P < 0.05). The blue bars are the confidence intervals of the means, and the red arrows are the comparisons between them. If an arrow from one mean overlaps the arrow of another treatment, there are no differences between means (P > 0.05) by Tukey’s test. A—net carbon assimilation rate (μmol CO₂·m⁻² s⁻¹); E—transpiration rate (mmol H₂O·m⁻² s⁻¹); WUE—water use efficiency (μmol CO₂/mmol H₂O); C_i/C_a—internal CO₂ concentration/ambient CO₂ concentration ratio; gsw—stomatal conductance (mol m⁻² s⁻¹); A/C_i—instantaneous carboxylation efficiency (μmol m⁻² s⁻¹/μmol mol⁻¹). H.s. + S.o. + Crop—Hancornia speciosa intercropped with annual crops (corn and pumpkin, in succession to each harvest sown between rows) and S. oleracea (‘Gueroba’) grown between the plants in the row. H.s. + S.o. – Hancornia speciosa intercropped with Syagrus oleracea (‘Gueroba’) cultivated between the plants’ rows. H.s.—Hancornia speciosa monoculture grown in full sun. H.s. + Crop—Hancornia speciosa intercropped with annual crops (corn and pumpkin, in succession to each harvest sown between rows)