晋西吕梁山区3种森林碳氮磷生态化学计量特征

Ecological stoichiometric characteristics of carbon,nitrogen,and phosphorus in three forests in the Lüliang Mountainous Area of Shanxi Province

以吕梁山区3种人工林（山杨林、落叶松林和油松林）为研究对象,采用标准样地的实测数据,探索植物叶片、枯落物及表层（0-20 cm）土壤的碳（C）、氮（N）、磷（P）生态化学计量特征,并进行相关性分析.结果显示,不同森林类型同一组分C、N、P含量差异显著,叶片、枯落物、土壤的C、N含量均为山杨林大于落叶松林和油松林,P含量为落叶松林大于山杨林和油松林.3种森林C、N、P含量均为叶片〉枯落物〉土壤,且叶片与枯落物C、N、P含量显著高于土壤;C：N、C：P均表现为枯落物〉叶片〉土壤,N：P则表现为叶片〉土壤〉枯落物.山杨林枯落物N：P与土壤N：P呈现显著正相关;落叶松林叶片C：N与枯落物N：P呈现显著负相关,叶片C：P与土壤N：P呈现显著正相关;油松林叶片N：P与土壤N：P呈现显著正相关.以3种森林类型总体来说,叶片与土壤N含量呈现显著正相关,而枯落物与土壤C、N、P之间均无显著相关.上述研究表明,环境因素对土壤C、N、P计量特征的影响较大,尤其是纬度和海拔对土壤C、N、P及C：N、C：P的影响最为显著,且均为显著正相关;结果可为进一步研究该地区不同树种的养分利用和循环特征提供科学依据.

Using a standard plot method, the stoichiometry of carbon（C）, nitrogen（N）, and phosphorus（P） in leaves, litter, and soil（0–20 cm depth） was investigated for three forest types： Populus davidiana, Larix principis-rupprechtii, and Pinus tabuliformis. The results showed that the stoichiometry of C, N, and P of the same component in the three forests were significantly different. The C and N contents in leaves, litter, and soil in P. davidiana forest were higher than those in L. principis-rupprechtii and P. tabuliformis forests were. However, P in the L. principis-rupprechtii forest was higher than that in the P. davidiana forest and P. tabuliformis forests were. The C, N, and P contents of the components in the three forests were, in order, leaves〉 litter 〉soil, and the three nutrient contents were significantly higher in leaves and litter than they were in soil. C：N and C：P in the three forests exhibited a trend of litter leaves soil, whereas that for N：P was leaves 〉soil〉 litter. There were highly significant positive relationships in N：P between the litter and the soil in the P. davidiana forest. Leaf C：N and litter C：P in the L. principis-rupprechtii forest were significantly negatively correlated, whereas N：P in the leaves and soil was positively correlated. There was a significant positive correlation in N：P between the leaves and the soil in the P. tabuliformis forest. In conclusion, the N contents in leaves and soil exhibited a significant positive correlation, whereas there was no significant correlation between C, N, and P in litter or soil. Environmental factors had a large influence on the stoichiometry of C, N, and P in soil. In particular, latitude and altitude had the most significant effects on C, N, P, C：N, and C：P and were significantly positively correlated. These results provide a scientific basis for further studies on nutrient utilization and the cyclic characteristics of different forests in this area.