辽东栎枝条分解过程中几种主要营养元素的变化

CHANGES OF NUTRIENT CONCENTRATION DURING THE DECOMPOSITION PROCESS OF OAK TWIGS

应用分解网袋法，对暖温带落叶阔叶林主要优势树种辽东栎小枝进行连续５年的分解研究，测定了Ｃ、Ｎ、Ｋ、Ｐ和Ｎａ５种元素在凋落物分解过程中的含量和剩余百分率的变化，发现这两个指标在这几种元素之间有很大的差异。从丢失速率上看（根据Ｏｌｓｏｎ的失重率常数ｋ），Ｋ元素的丢失速率明显高于其它４种元素；而从这几种元素含量变化的格局上看，Ｋ的含量在整个５年的分解过程中是不断降低的，Ｃ也有这样的趋势，Ｎ的含量有不断上升的趋势，而Ｐ和Ｎａ则表现为先升高后降低的趋势。

With the litterbag method, the decomposition of twigs of oak ( Quercus liaotungensis ), a dominant tree species in warm temperate deciduous broad leaved forests,had been investigated in five years consecutively.Changes of concentrations and the remaining percentage of five nutrient elements,namely C,N,K,P,Na, were determined. It was found that changes of nutrient concentrations and remaining percentages differed among those five nutrients throughout the five year decomposition.Based on the Olson exponential equation,K had the highest decomposition constant. As for the change pattern of nutrient concentration, K decreased continually. C had almost the same tendency. N had the tendency of increase. P and Na increased during the first stage of the decomposition, and then decreased.