Die Ab- und Auswaschung von Fluorid als Mechanismus zur Verringerung der Fluorakkumulation in Nadeln und Blättern

Wien

1981

4 Abb., 16 Lit. Ang., 3 Tab.

Unselbständiges Werk

673

200004834

Wahing off and washing out of fluoride as a mechanism of fluoride reduction in needles and leaves. As has been known so far, diffusion of fluoride through intact isolated cuticels is very small. However, diffusion of fluoride into leaves grown under natural environmental conditions is sufficient to produce damage to the leaf tissue when fluoride containing solutions are applied to astomatous leaf surfaces. An attempt was therefore made to evalute the importance of transcuticular fluoride loss from leaves of woody plants. A rather high amount of fluoride can be washed within 20 sec from leaves collected in immission areas. With further waching of up to 2 hours, the amount of fluoride found in the washing solution decreases rapidly. Experiments with Picea abies and Fagus sylvatica show that anly a small part of the internal fluoride is translocated to the leaf surface and easily removed by washing. In a chronically polluted area most of the surface fluoride will come directly from the imissions. Rainfall mainly decreases the high concentration of this surface-adsorbed fluoride and, therefore, transcuticular uptake.