摘 要 ：本文研究了云南中甸地区亚高山暗针叶林的优势树种油麦吊云杉(Picea brachytyla var. complanata)和长苞冷杉(Abies georgei)幼树(20年生)的光合特征、光合速率的变化规律及其与环境主要生态因子的关系。结果表明两种杉树光合作用的光饱和点均较低，且长苞冷杉较油麦吊云杉更喜阴，它的光合速率(3.24CO2mgg-1DWh-1)也比云杉的低(3.74CO2mgg-1DWh-1).在试验海拔3300m地段上，云、冷杉的光合作用都存在日中压制现象，采伐迹地上的幼苗尤为突出；受温度和蒸发量的影响在一年中以7月份光合速率最高。两树种的光合速率都是随着海拔的升高而降低。森林被大面积皆伐后，迹地上云、冷杉幼树的光合速率明显下降，其中以长苞冷杉的降低幅度最大。
Abstract:Abstract Picea brachytyla var. complanata and Abies georgei are main dominant of subalpine dark coniferous forest in Zhongdian. The light saturation point of both species are lower, but the adaptive ranges of P. brachytyla var. complanata for light intensity is higher than that of A. georgei, and the photosynthetic rate of the former (3.74 CO2mgg-1 DWh-1) is higher than that of the latter (3.24 CO2mgg-1 DWh-1) too. The types of diurnal changes in photosynthetic rates of two species at an altitude of 3300 metres above sea level all show double peaks curves, and their seasonal changes in photosynthetic rates exhabit the forms of single peak. The rates of photosynthesis of both species in the cutting blank decrease obviously as compared with that of under the canopy and fall range of photosynthtic rates of A. georgei is higher.