| Abstract: | The Si concentration in 1 year old needles from Norway spruce (P. abies) was determined at 39 sites within an area of 150 km2. The sites had uniform elevation, precipitation and immission characteristics. The mean value was 1423 μg Si g?1, and the coefficient of variation between sites was 29 %. There was no correlation of Si concentration in needles with soil pH in the range of pH 3.5 to 7.6, but significant negative correlations with soil organic matter concentration and with the effective cation exchange capacity were found. Silicon in needles correlated positively with Al, La, and Fe in needles, but showed no correlation with 20 other elements. The seasonal variation of Si concentration in needles showed a nonuniform increase with time. The seasonal changes of Si were similar to those of Ca. The investigation of 4 successive needle age classes, however, showed a strictly linear increase of the Si concentrations. |
