四川缙云山常绿阔叶林幼龄栲树光合生理生态研究

研究了四川重庆缙云山自然保护区常绿阔叶林中幼龄栲树的光合生理生态特性．通过系统观测，测定了幼龄栲树光合作用年变化、日变化的特征；进行了幼龄栲树四季生长速率和生长最适条件的分析．结果表明，幼龄栲树的光补偿点是０．４７０ｋｌｘ，光饱和点是２０ｋｌｘ；温度和光强是决定幼龄栲树光合速率的重要因子．幼龄栲树光补偿点和光饱和点都较低，说明它具有较强的利用弱光的能力，是属于林下耐阴的树种，这是与成年栲树的喜阳性有差异的．因此，幼龄栲树可作为下木配置，特别是配置在针阔混交林下，这对植树造林和林种配置有非常重要的意义．

A STUDY ON THE PHOTOSYNTHETIC ECOPHYSIOLOGY OF YOUNG CASTANOPSIS FARGESII IN THE EVERGREEN BROAD-LEAVED FOREST OF JINYUN MOUNTAIN

The photosynthetic ecophysiology of young Castanopsis fargesii in the evergreen broad-leaved forest of Jinyun mountain is studied. Aualying systematicly the young Castanopsis fargesii about annual variation and daily variation of photosynthetic ecophysiology, and the growth rate in four seasons and the suitest condition of growth, we gained the results that the saturation point of the young Castanopsis fargesii is 20 klx, and its compensation point is 0. 479 klx, light intensity and temperature are the most important ecdogical factors affecting Pn. Because the saturation point and the compensate point are lower, the young Castanopsis fargesii is shade-tolerant and with strong ahility to use weak light, which is different from the adult tree. Thus, young Castanopsis fargesii can be used as lower-step species in forest during afforesting, especially, in the needle-leaved and broad-leaved mixed forest.