Studies on litter decomposition processes in a temperate forest ecosystem. I. - Change of organic matter in oak (Quercus liaotungensis Koidz.) twigs

The litter bag method was used in this study on the decomposition of twigs of an oak (Quercus liaotungensis Koidz.) which is dominant in the warm temperate deciduous forests. This continual 5-year investigation was to measure the changes of organic compounds in twig litter. The decomposition of oak twigs based on rates of the mass loss during the first 5 years was simulated using the Olson exponential equation. The simulated data fitted well with the observed values. Oak twigs were predicted to reach 95% mass loss within 21 years. During the first 5 years, the concentration of protein in the remaining litter increased from 3.5% to 5.5%, while the concentration of hemicellulose decreased from 16.0% to 8.0%. However, there was no obvious change in the concentrations of lignin and cellulose. The losses of lignin, crude-cellulose and hemicellulose could be well simulated using the Olson exponential equation. However, this was not true for cellulose and protein.