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Seasonal changes in some photosynthetic properties of Ceratonia siliqua (carob tree) leaves under natural conditions
Author(s) -
Nunes Maria Antonieta,
Cochicho Ramalho José Domingos,
Silva Rijo Paula da
Publication year - 1992
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.1399-3054.1992.tb01333.x
Subject(s) - ceratonia siliqua , sclerophyll , photosynthesis , mediterranean climate , botany , stomatal conductance , biology , limiting , horticulture , agronomy , chemistry , ecology , mechanical engineering , engineering
Rates of photosynthesis and leaf conductance of the leaves of carob trees ( Ceratonia siliqua L.) growing in natural conditions were measured during the course of the seasons to define the effects of the main climatic factors limiting growth in the region: temperature during the winter and water in the summer. The highest photosynthetic rates were measured in spring and autumn and could reach 25 μmol m −2 s −1 with optimal temperature and available water. Due to lower temperatures (4 to 6°C in the night) these values were frequently around 15 μmol m −2 s −1 during winter, but the strongest depression was due to prolonged drought in summer. However a reduction in photosynthesis rate down to 5 μmol m −2 s −1 occurred only after depletion of all the available water in the soil layer up to a depth of 50 cm. In the end of the summer, leaf conductance and water potential were in the order of 20 mmol m −2 s −1 and −3 MPa respectively. Compared to other trees that make up the Mediterranean sclerophyll forest, the photosynthetic activity of carob is high, and the tree tolerates a considerable depletion of soil water.