Leaching of phenolic compounds from leaf and needle litter of several deciduous and coniferous trees

Abstract

Leaf and needle litter of the deciduous trees beech, birch, oak, ash, common maple, hornbeam, hazelnut, willow, poplar, hawthorn and the coniferous trees pine, spruce-fir, douglas-fir and larch were collected immediately after “leaf-fall” in October and analysed for their water-soluble phenolic compounds. By collecting leaf and needle litters three times in the period from October to January leaching rates of these organic compounds could be determined. There were considerable differences in the amount and leaching rate of water-soluble phenolics between litter-types. The concentration found in freshly deposited litter of the leaf-forming species was high and most of the water-soluble phenolics in these litter types were released in the period from October to January. In needle litters concentrations of water-soluble phenolics were low and they leached at a slow rate. By using gas chromatography, 14–18 phenolic compounds could be identified in the leachates. Benzoic acids dominated the phenolic spectra in October. In the course of time cinnamic acids became more important in the water-leachates. The results are discussed in view of their importance for the relationship between woodland-types and understory vegetation.