中文摘要：

以刨花楠（Machilus pauhoi）幼苗为研究对象,通过盆栽施肥试验,探讨不同氮（N）、磷（P）供应水平下刨花楠叶片N、P元素含量的动态变化及与土壤养分的相关性.N、P处理各设定4个梯度,N1、N2、N3、N4及P1、P2、P3、P4,N、P肥施加量分别是初始土壤的2倍、4倍、8倍和16倍,不同N、P处理共用一组对照（CK）,共9种处理,每组处理3个重复,并分别于3月、7月、11月对成熟叶片及土壤进行采样分析.结果显示：刨花楠幼苗叶片N、P含量及N：P值分别为14.63-26.53 mg/g、0.64-1.84 mg/g和10.04-23.21.施N肥叶片N含量及N：P随季节变化呈现出低（3月份）—高（7月份）—低（11月份）的变化趋势,叶片P含量呈现高—低—高的趋势;施P肥叶片P含量也随季节变化呈现出先升高后降低的变化趋势.施N或施P显著增加了刨花楠幼苗土壤及叶片的N、P含量,分别增加或降低土壤及叶片的N：P值（P〈0.05）;施N或施P也显著影响了土壤pH（P〈0.05）及叶片N、P含量与土壤养分的关系.综上表明土壤中N、P供应量影响刨花楠叶片中的N、P含量.

英文摘要：

For a comprehensive understanding of the nutrient conservation mechanism of Machilus pauhoi in the subtropical zone, we need to know the response of leaf nutrient contents to fertilizers. This paper aimed to study the effect of nitrogen and phosphorus fertilization on leaf N and P stoichiometric characteristics of M. pauhoi seedlings. A microcosm experiment with N and P fertilization was designed to observe the dynamic change of leaf N, P content and their correlation with soil nutrients. The treatments included 5 levels of N addition of 0, 2, 4, 8, 16 times of initial soil, respectively, as control（CK）, N1, N2, N3, and N4; P addition of the same gradients as CK, P1, P2, P3, and P4; we did three replicates for each treatment. The result showed a range of 14.63-14.63 mg/g for leaf N, 0.64-1.84 mg/g for P content and 10.04-23.21 for the N：P ratio of M. pauhoi seedlings. By N fertilization, a low–high–low pattern was observed in the leaf N content and N：P ratio, but an opposite pattern in the leaf P content; by P fertilization, the leaf P content first decreased then increased with the season. N or P fertilization significantly increased the leaf and soil N or P content respectively, and both significantly affected the soil pH（P〈0.05）, the leaf N,P content and soil nutrient relationship. N addition improved the stoichiometric ratio, while P addition reduced it（P〈0.05）. The results indicated that the N and P content in soil would affect the leaf N and P content of Machilus pauhoi seedings.