ORGANIC-MATTER AND NUTRIENT DYNAMICS OF THE LITTER LAYER ON A FOREST RENDZINA UNDER BEECH

The decomposition of beech (Fagus sylvatica L.) leaf litter was investigated in a calcareous beech forest using mesh cages containing two layers, fresh leaf litter (O layer), and partly decomposed leaf litter (F layer). C loss was monitored, together with the changes in the contents of total N, hexosamines, ash, Na, K, Mg, Ca, Fe, Mn, Al, Cl, Sulphate, and Phosphate. In 1-mm mesh cages, which excluded access to the macrofauna, the mean annual loss rates for C were 28% in the O leaf litter and 17% in the F leaf litter, totalling approximately 23% for the two layers. The mean loss rates from the 12-mm mesh cages were 54% in the O leaf litter and 58% in the F leaf litter. Degradation processes and feeding activities caused increased contents of ash, total N, and hexosamines in the O layer of both treatments. This increase was greater for the ash and smaller for N, glucosamine, and galactosamine in the 12-mm mesh cages. The sum of ions (Na + K + Mg + Ca + Fe + Mn + Al + Cl + SO4 + PO4) and also the contents of most single ions were not markedly affected, despite the much higher ash content in the O leaf litter of the 12-mm mesh cages. The ash content increased mainly as a consequence of contamination by soil, which increased the contents of Fe and Al in the ash.