暖温带落叶阔叶林辽东栎枝条分解过程中有机物质的变化

CHANGE OF ORGANIC MATTER IN THE DECOMPOSING OAK TWIGS IN THE TEMPERATE FOREST ECOSYSTEMS

应用网袋法对暖温带地区广泛分布的乔木树种辽东栎（ＱｕｅｒｃｕｓｌｉａｏｔｕｎｇｅｎｓｉｓＫｏｉｄｚ．）枝条分解进行了连续５年时间的观察，并测定了凋落物在分解过程中有机质（纤维素、木质素、蛋白质）的变化。用Ｏｌｓｏｎ的指数方程对分解枝条重量的减少进行了模拟，并预测暖温带地区辽东栎枝条完全（９５％）分解需要约２１年的时间。在各有机成分含量的变化上，表现出明显不同的分异。蛋白质的含量随着分解过程的不断进行，从３．５％增加至５．５％，半纤维素则从１６．０％下降至８．０％，而粗纤维和木质素的含量出现了上下波动的情形。经过拟合，凋落物的丢失速率符合Ｏｌｓｏｎ的指数降解曲线，含量较大的粗纤维和木质素的减少也较好地符合Ｏｌｓｏｎ的指数降解曲线，半纤维素也可以用Ｏｌｓｏｎ指数方程拟合，但蛋白质的拟合效果较差。

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