【摘要】 本文使用Li-6400光合测定系统研究了加拿大黄桦(Betula alleghaniensis)3 a生幼苗叶片的光合生理特性。结果表明,加拿大黄桦幼苗净光合速率日变化曲线呈双峰型,有明显的“午休”现象;正常天气条件下,加拿大黄桦幼苗叶片光饱和点为813.8μmol.m-2.s-1,补偿点为39.7μmol.m-2.ss-1,说明其具有一定的耐荫性。更多还原

【Abstract】 The photosynthetic physiological characteristics of 3-yr-old seedlings of Betula alleghaniensis were studied by using Li-6400 photosynthetic assay system.The results revealed the curve of net photosynthetic rate of the seedlings that had a changing course daily in double peaked and appeared obvious phenomenon of ’noon break’.On the normal weather condition,the light saturation point in the leaves was 813.8 μmol·m-²·s^-1 and the light compensation point was 39.7 μmol·m^-2·s^-1.The results indicate that Betula alleghaniensis has a definite tolerance of shade.更多还原