The change pattern of C/N ratio in branches and leave were accordant i.e. the C/N went down and reached vale in the first six weeks, and then the C/N ratio varied with treatments.

• 枝条、叶片碳氮比的总体变化规律是一致的，即在处理前6周内碳氮比显著下降，出现一个低谷，在第8周后因试验处理不同而有差别。