The decomposition of plant litter fall in an oak-linden-hornbeam forest and an oak-pine mixed forest of the Białowieża National Park

The decomposition of hornbeam, linden and oak leaves in an oak-linden-hornbeam ,(Tilio-Carpinetum) forst and of pine and spruce needles in an oak-pine mixed forest (Pino-Quercetum typicum) of the Białowieża National Park were studied. The decay of the hornbeam and linden leaves progressed at the same rates, while that of oak leaves was slower. During the first year in the oak-pine mixed forest, the decay of pine needles was more intense than that of spruce needles, then during later periods, the rate of decomposition of spruce needles exceeded that of pine. The initial rates of decomposition were determined by the C/N ratio and the content of easily soluble components in the starting materials. The decomposition rate coefficients were: 1.06 for hornbeam leaves, 0.91 for linden leaves, 0.63 for oak leaves, 0.21 for pine needles and 0.30 for spruce needles; the time necessary for 95%;, of the initial material to decay was from 3 to 5 years for the oak-linden-hornbeam forest and from 10 to 14 years in the oak-pine mixed forest. Elements can be arranged in the following orders on the basis of their rates of release: K> Mg > P> > Ca > N or K> Mg > Ca > P> N. A decisive role is played by microbiological processes in the release of nitrogen, phosphorus and calcium, while potassium and magnesium are released mainly by leaching