Effects of Zn and HCO₃⁻ on the Zn concentration (mg Kg^-1 DW) in the roots, stems and leaves of the four plant species.

Note: Values are the mean (M) ± standard error (SE) (n = 5). Different lowercase letters indicate a significant difference between the four treatments for the same plant organs at p < 0.05; different capital letters indicate a significant difference in organs of the same species under the same treatment at p < 0.05.