Air pollutant uptake by xerophytic vegetation: Fluoride

• Published in: Environmental and experimental botany 1980-01, Vol.20 (3), p.259,267-265,269
• Main Authors: Ares, J.O., Villa, A., Mondadori, G.
• Format: Article
• Language: English
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/0098-8472(80)90023-4

Drought resistance has been found to correlate in some species with resistance to air pollutants. In xerophytic species, drought resistance is often associated with anatomical and physiological leaf characteristics, which control plant water loss. The characteristic path of pollutant uptake in these species could be different from that reported as widespread among mesophytic plants. Measurements of fluoride content in intact and washed plant leaves, leaf water potentials, and exposure to pollutant carrying winds were performed in the vicinity of an aluminum smelter. Electronic fluorine specific microprobe measurements were made to localize fluoride in leaf tissues. The results indicate that fluoride uptake by these species consists in a deposition-adsorption upon the external leaf surface, followed by a slow diffusion to inner tissues which is regulated by the water potential at the epidermis and cuticle. The absence of fluorine accumulation in substomatic tissues suggests that the uptake of gaseous fractions of fumes through stomata would be relatively unimportant when quantitatively compared to the above mechanism.