Ontogenetic patterns of CO sub 2 exchange of Quercus rubra L. leaves during three flushes of shoot growth I. median flush leaves

摘要: Oak (Quercus) seedlings exhibit a pattern of shoot growth known to place demands on carbohydrate and nutrient reserves. This study was designed determine ontogenetic patterns in CO{sub 2} exchanges properties red oak leaves, if individual leaf exchange rates (CER) increase response the assimilate demand placed seedling during flushing. Northern (Q. rubra L.) were grown environments favorable for multiple flushes growth. Measurements CER single, attached, median leaves from each flush made over range photosynthetic photon flux densities plants at nine stages development through three Carbon dioxide rate increased up beyond full expansion before decreasing an unusual photosynthesis ontogeny. Furthermore, first- second-flush initially decreased then conjunction with third These indicate that have capacity adjustment sink demand.