Seedlings of spruce and beech were transplanted into either nursery soil or F-contaminated forest soil collected from near an aluminum smelter. Both soils were fertile sandy loams with >5 % organic matter and a pH between 6 and 7. They differed, however, greatly in their contents of "soluble F" which amounted to 11 ppm in the nursery soil but 114 ppm in the contaminated soil. After one or two years' growth in F-free air, the F content of foliage and the growth of plants were investigated.
In both species foliar F contents were distinctly increased in F-contaminated soil (Table 1 ), but remained in the range considered "normal". More important is that in both species, height growth and the dry weight of roots and shoots was diminished in the contaminated soil (Table 2). Thus, F-emissions over decades of an aluminum smelter may have negative effects on trees after the shut-down of the plant, if these emissions have greatly increased the fraction of "soluble F" in the soil.