中文摘要：

选取黄土高原子午岭林区的幼龄林、近熟林和成熟林3个林龄阶段的辽东栎林为对象,通过测定林内植物、枯落物和土壤的碳（C）、氮（N）、磷（P）含量,研究不同生长阶段植株、枯落物及土壤的化学计量学特征.结果显示：林内植物各器官（叶、枝、干和根）之间C、N、P含量均存在显著性差异,分别在245.3～492.6 g/kg,1.57～20.6 g/kg和0.11～1.63 g/kg之间;枯落物C、N和P含量分别在283.5～329.0g/kg,11.5～13.2 g/kg和0.73～1.06 g/kg之间.在不同生长阶段,植物C含量无显著性差异;植物N和P含量,枯落物和土壤C、N和P含量均存在显著性差异.具体表现为随着林龄的增加,植物叶片C∶N和C∶P显著增加,N∶P先增加后减小;枯落物C∶N、C∶P和N∶P均显著增加;土壤C∶N显著减小,C∶P先增加后减小,N∶P无显著性差异.植物叶片和枯落物与土壤N和P含量和化学计量特征呈显著的线性相关,说明土壤中N、P供应量影响植物体中的N、P含量.

英文摘要：

In this study, the contents of carbon（C）, nitrogen（N） and phosphorus（P） in plants, litter and soil were determined at three different ages in Quercus liaotungensfs forests （young, near-mature and mature forest） in Ziwuling area of Loess Plateau. The results showed that the contents of C, N and P varied in different plants organs, which were in the range of 245. 3～492.6 g/kg, 1.57～20.6 g/kg and 0.11～1.63 g/kg, respectively. The contents of C, N and P in plant litter were in the range of 283.5～329.0 g/kg, 11.5～13.2 g/kg and 0.73～1.06 g/kg, respectively. There was no significant difference in plant C content among Quercus liaotungensis forests at different ages, while the contents of N and P in plants and the contents of C, N and P in litter and soil significantly differed with forest age. With the increasing forest age, the ratios of C ：N and C：P in plant leaves and the ratios of C ： N, C ： P and N ： P in plant litter significantly increased, N ： P ratio in plant leaves, as well as C ： P ratio in soil, increased at first and then decreased, C ： N ratio in soil greatly decreased and N ： P ratio in soil did not obviously change. Positive correlations existed between plant and soil for both N and P contents, showing that the supply of N and P in soil affected the contents of N and P in plant.