Effects of Relative Humidity on Carbon Isotope Fractionation in Plants
1991; Thieme Medical Publishers (Germany); Volume: 104; Issue: 4 Linguagem: Inglês
10.1111/j.1438-8677.1991.tb00232.x
ISSN0932-8629
AutoresS. Madhavan, Isabel Treichel, Marion H. O’Leary,
Tópico(s)Tree-ring climate responses
ResumoAbstract Four C 3 plants and a C 4 plant were grown from seeds at four levels (30, 45, 60, and 75 %) of relative humidity. All plants were subjected to a 16 h day, at 500 μE/m 2 .s −1 photon flux density. Mature leaves were analyzed for their carbon isotopic composition. Isotope fractionation decreased by up to 3 ‰ with decreasing relative humidity in all C 3 plants, while the opposite trend was observed in the C 4 plant. The observed shifts in both C 3 and C 4 plants are attributed to decreased stomatal conductance at low relative humidity, resulting in a smaller P i .
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