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Effect of Water Stress, Temperature, and Light on Photosynthesis in Alder Seedlings
Author(s) -
HARI PERTTI,
LUUKKANEN OLAVI
Publication year - 1973
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1973.tb04808.x
Subject(s) - photosynthesis , water stress , botany , vapour pressure of water , alder , vapour pressure deficit , chemistry , soil water , water content , water vapor , environmental science , horticulture , biology , soil science , transpiration , geotechnical engineering , organic chemistry , engineering
Seedlings of Alnus incana (L.) Moench were studied in controlled environmental conditions. Net photosynthetic capacity of four plants simultaneously as well as light, temperature, and atmospheric water pressure deficit were continuously recorded during approximately two months. The potted plants were continuously given known quantities of water. Two different effects of water stress were found in the experimental plants. When sufficient amounts of water had been available to them, photosynthetic CO 2 fixation rates largely followed the variation in temperature and light. On the other hand, after prolonged water stress, higher temperatures caused a large decrease in net CO 2 uptake even if the plant apparently had sufficient water during the actual measurements. Possible mechanisms for this effect are discussed. Effects of water stress on photosynthesis were studied at a constant temperature as well as in conditions where temperature, light, soil water content, and atmospheric water vapor pressure were allowed to vary in a complex pattern. Mathematical models for expressing net CO 2 uptake as a function of environmental variables were constructed for both of these experimental situations. However, only the latter approach clearly demonstrated the fundamental role of temperature in controlling the photosynthesis of plants under water stress.