<正>应用¨一cor6400便携式光合作用测定系统以及常规方法测定了海南岛热带山地雨林演替早期6个先锋树种与8个非先锋树种叶片的生理特征。结果表明：先锋树种的单位面积最大净光合速率、单位干重最大光合速率和单位干重暗呼吸速率显著大于非先锋树种的（P<0.05）；先锋树种的比叶面积、叶片氮含量和单位面积暗呼吸速率与非先锋树种差异不显著（P>0.05）。先锋树种、非先锋树种的叶片氮含量和叶片磷含量均与比叶面积显著相关，但先锋树种的斜率低于非先锋树种。先锋树种的单位面积最大光合速率、单位干重最大光合速率均与比叶面积显著正相关；而非先锋树种的单位面积最大光合速率与比叶面积显著负相关，单位干重最大光合速率均与比叶面积显著正相关。叶片光合功能特征与结构特征关系的不同可能是先锋树种与非先锋树种形成不同特征的原因。

This paper dealt with the seed quality changes of Pinus massoniana treated by different magnetic intensity. The results showed the germination rate of mid-vigorous seeds increased greatly under 0. 2 T and 0.3 T magnetic intensity for l0 rain or 15’rain, especially under 0. 3 T for 15 min, the germination rate was raised from 66% to 83%. To highvigorous seeds with 83% germination rate, the germination rate had any fewer changes after treating with the same intensity of magnetic field. However, seed vigor was still improved. In addition, POD activity increased with treating time under magnetic field intensity above. POD activity of mid-vigorous seeds increased 100% nearly treated for 15 rain under 0.3 T magnetic field intensity, and POD activity of high-vigorous seeds inereased 74% also. On the other hand, SOD activity of mid-vigorous seeds was improved greatly from 0. 20 U/(g ? min) to 0.79 U/(g ? min). In contrast, SOD activity of high-vigorous seeds was cut down.