Keywords: 
• forest biology /
• photosynthetic characteristics /
• environmental factors /
• Aster novae－anglia /
• multivariate stepwise regression analysis

Abstract: One－year－old cuttings of four cultivars of Aster novae－angliae，Purple Dome，Herbstschnee，Barrs Pink，and Andenken an Alma Potschke，were studied to determine their photosynthetic physio－ecological characteristics using a multivariate stepwise regression analysis. Results indicated that the light adaptive capacity was high and in the order：Purple Dome ＞ Herbstschnee＞Barrs Pink＞Andenken an Alma Potschke with light compensation and saturation points differing. For apparent quantum yield，the order was：Herbstschnee ＞ Andenken an Alma Potschke＞Purple Dome ＞Barrs Pink；and for the dark respiration rate it was：Andenken an Alma Potschke＞Purple Dome＞Herbstschnee＞Barrs Pink. These four cultivars had strong diurnal changes in the net photosynthetic rate with single－peaked curves at midday in spring and autumn，but double－peaked curves in summer. These peak net photosynthetic rates were earlier in spring than in summer or winter. Double－peaked curves had greater initial peaks，and the photosynthetic noon break was strong at midday in summer（midday depression of photosynthesis）. A multivariate stepwise regression showed that the key environmental factors influencing the net photosynthetic rate included photosynthetically active radiation（PAR），air temperature，and leaf temperature；however，these differed for each cultivar.［Ch，3 fig. 3 tab. 21 ref.］