Leaf Metabolism During Summer Drought in Quercus Ilex Trees with Lifetime Exposure to Elevated CO2

• Published in: Journal of biogeography Vol. 22; no. 2/3; pp. 255 - 259
• Main Authors: Chaves, M. M., Pereira, J. S., Cerasoli, S., Clifton-Brown, J., Miglietta, F., Raschi, A.
• Format: Journal Article
• Language: English
• Published: Blackwell Scientific Publications 01-03-1995
• Subjects: Acclimatization; Atmospherics; Carbon dioxide; Elevated CO2 Interactions; Leaves; Photosynthesis; Plants; Starches; Sugars; Tree growth; Trees
• ISSN: 0305-0270; 1365-2699
• DOI: 10.2307/2845919

A marginal improvement in the response of Quercus ilex adult trees to drought appears to occur under a long-term natural CO2enrichment. This is expressed, for example, by the absence of midday stomatal closure in trees growing under elevated CO2. Some protection against high irradiance and high temperature seems also to occur at the photochemical level, presumably as a result of more carbon available to the consumption of excess light energy. This would allow a better performance of the plants grown under elevated CO2during the warmer hours of the day and therefore playing an important adaptation role under drought conditions. A marginal increase in the concentration of soluble sugars and starch was observed in the leaves of trees growing at elevated CO2as compared with plants at ambient CO2as compared with plants at ambient CO2, mainly during the midday hours. We may speculate that this will be advantageous both in terms of carbohydrate reserves for growth (e.g. more roots) and osmotic adjustment.