ABSTRACT
The objective of this study was to evaluate gas exchanges in seedlings of forest species grown in saline soils and subjected to soil waterlogging cycles. The experimental design was completely randomized in a factorial arrangement, with four forest species: Myracrodruon urundeuva Fr Allemão, Mimosa caesalpiniifolia Benth, Tabebuia impetiginosa (Mart. ex. DC.) Standl and Azadirachta indica A. Juss, two soil salinity levels (1.2 and 8.6 dS m-1) and two water regimes (with and without waterlogging). Measurements of stomatal conductance, transpiration and CO2 assimilation rate were performed before and after each waterlogging period. The interaction of the highest saline level (8.6 dS m-1) and waterlogging caused greater reductions in leaf gas exchange, except for Mimosa caesalpiniifolia Benth. Tabebuia impetiginosa (Mart. ex. DC.) Standl was the species with highest sensitivity to both studied factors of stress.
Key words:
photosynthesis; salt stress; water excess; Caatinga
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Means followed by the same letter do not differ statistically by Tukey test (p > 0.05) (A); Bars with the same uppercase letters, for salinity, and by the same lowercase letters, for water regime, do not differ statistically by Tukey test (p > 0.05) (B)
Means followed by the same letter do not differ statistically by Tukey test (p > 0.05) (A); Bars with the same uppercase letters, for salinity, and by the same lowercase letters, for species, do not differ statistically by Tukey test (p > 0.05) (B)
Means followed by the same letter do not differ statistically by Tukey test (A); Bars with the same uppercase letters, for salinity, and by the same lowercase letters, for species, do not differ statistically by Tukey test (B); Means followed by the same uppercase letter between treatments and lowercase letter in the treatment, do not differ statistically (C)