中文摘要：

氮（N）、磷（P）是维系植物生长发育的两种重要的基础营养元素。区域尺度范围的N、P元素化学计量研究可以更好地认识陆地生态系统的空间尺度格局变化。同时,与植物体内各个器官之间（如根叶之间）的N、P含量密切相关,使其能够快速应对外部环境变化,调节生长速率,使生物体达到最适生长。选取西双版纳、贡嘎山、鼎湖山、武夷山和尤溪5个中国南方地区的木本植物（以乔木为主）为研究对象,分析了植物根、叶器官内部以及器官之间的N、P化学计量学特征。结果表明,上述5个地区相同器官的N、P含量变幅较大,造成地区间养分含量的差异可能是由于土壤养分、温度和降水。同一地区植物不同器官的N、P含量都是叶大于根。根或叶内部的N-P、N-N：P以及P-N：P基本呈现等速比例关系,表明在各器官内部N、P含量相互促进的作用明显。根、叶之间的N含量、P含量以及N：P则呈现异速比例关系。说明不同器官之间对某种养分的分配彼此相互影响、相互协调。

英文摘要：

Nitrogen（N） and phosphorus（P） are two important foundational nutrition elements for plant growth and development. Stoichiometri characteristics of N and P at a regional scale can help us better understand spatial pattern variations of the terrestrial ecosystem. Meanwhile, the concentrations of N and P in different plant organs are closely related and they can quickly respond to the changes of the external environment and regulate the growth rate of plants, allowing plants reach the optimum growth status. This paper analyzed the stoichiometric characteristics of N and P in roots and leaves of plants in Xishuangbanna, Gonggashan, Dinghushan, Wuyishan and Youxi in South China. At Xishuangbanna, Gonggashan or Dinghushan, we used data of N and P content in roots or leaves from a data set and the other data were derived from the field experimental analysis in Wuyishan and Youxi region. Allometric scaling relations of N, P and N： P in roots and leaves were analyzed using standardized major axis estimation（SMA）.The results showed that big changes in N and P contents existed between roots and leaves from the above 5 regions; N and P contents in the leaves were higher than those in the roots. The difference in nutrient content of inter-regional plants may be resulted from the soil nutrients, temperature and precipitation. Allometric scaling relation of N vs. P, N vs. N： P and P vs. N： P in roots or leaves was not related significantly. It is suggested that the function which N, P promoted mutually in organs was obviously. Through the regression analysis of 5 organs, the N, P contents among different organs were also highly correlated, which demonstrates that nutrient allocation between different organs interacts with each other and coordinate mutually.