探讨云南松的生态化学计量对海拔的响应及云南松不同器官的养分元素与土壤养分元素的关联性,为云南松林的经营管理提供理论支持。以云南西北部不同海拔云南松林为研究对象,比较1 900~2 900 m范围内不同海拔云南松的不同器官和根际土中的碳(C)、氮(N)、磷(P)及其化学计量特征。结果表明:1)该地区云南松针叶N含量高于细根N含量,针叶和细根N/P均小于14;土壤C(13.037 g/kg)、N(1.446 g/kg)、P(0.473 g/kg)含量均低于我国表层土壤C、N、P平均含量。2)根际土的N、P含量、C/N、C/P、N/P受海拔显著影响;而云南松针叶、细根的养分含量及化学计量特征在不同海拔下无显著变化。3)云南松针叶的C含量、C/N分别属于敏感态、弱稳态,其余指标属于绝对稳态型;而细根的C、N、P、C/N、C/P、N/P利用稳态性模型模拟结果不显著,均属于绝对稳态型。4)云南松生长在低氮少磷的瘠薄土壤中,生长主要受N的限制,但云南松通过增强吸收N到植物中,将更多N分配到针叶以适应海拔的变化;云南松对1 900~2 900 m海拔范围内的根际土环境具有较好的适应性。本研究揭示了滇西地区云南松化学计量特征对海拔的适应性,为进一步探索云南松的养分分配模式和环境适应性研究提供了一定的数据支撑。

This study explores the response of eco-chemometrics of Pinus yunnanensis to elevation and investigates the relationship between nutrient elements in different organs of P.yunnanensis and soil nutrient elements,providing theoretical support for the management of P.yunnanensis forests.The natural secondary forests of P.yunnanensis at different elevations in Northwest Yunnan were studied,carbon(C),nitrogen(N),phosphorus(P)and their stoichiometric characteristics in different organs and rhizosphere soil of P.yunnanensis at different elevations(1 900 to 2 900 m)were compared.The results showed that the N content of needles was higher than that of fine roots,and the N∶P ratio of both needles and fine roots was less than 14.Additionally,the contents of soil C(13.037 g/kg)、N(1.446 g/kg)and P(0.473 g/kg)were lower than the average levels of topsoil in China.The contents of N,P,C∶N,C∶P,N∶P in rhizosphere soil were significantly affected by elevation,while the nutrient contents and stoichiometric characteristics of needles and fine roots of P.yunnanensis showed no significant changes across elevation gradients.The contents of C and C∶N in needles of P.yunnanensis belong to sensitive steady state and weak steady state respectively,the other indexes belong to absolute steady state.While the contents of C,N,P,C∶N,C∶P,N∶P in fine roots of P.yunnanensis were not significant,all belonging to absolute steady state.The growth of P.yunnanensis in poor soil with low nitrogen and phosphorus,and its growth is mainly restricted by N,but P.yunnanensis adapts to the change of elevation gradient by increasing N absorption into plants and distributing more N into needles P.yunnanensis has good adaptability to the rhizosphere soil environment in the range from 1 900 to 2 900 m.This study revealed the adaptability of stoichiometric characteristics of P.yunnanensis to elevation in western Yunnan,and provides data to support further research on nutrient distribution pattern and environmental adaptability of P.yunnanensis.