Studies on leaching from spruce twigs and beech leaves.

Leaching, depending on the acidity of the eluent, was investigated for K, Mg and Mn. The curves for the leachate concentration versus time could be described by a power function. Leaching from old needles exceeded leaching from young needles to a high degree, but the ratios of the leached elements were almost equal. A method for continuous measurements of pH change in solutions contacting plant materials was developed. The results were in agreement with data on acidity changes in water falling through spruce or beech canopies.