FIELD WATER RELATIONS OF CAPPARIS-SPINOSA L

This paper describes the water relations in expanded leaves of Cappari s spinosa under natural conditions during summer. Predawn water potent ial was sustained above -2.3 MPa. The lowering of solute potential may not be attributed to osmotic adjustment, since concentrations of prol ine and sugars were reduced. Stomatal conductance of leaf adaxial surf ace was higher than that of the abaxial. At noon, stomatal conductance up to 100 mmol m(-2) s(-1) was measured concomitantly with turgor los s point. The results indicate that C. spinosa is a stenohydric plant, which during the summer is largely free of competition for water with other species of the Mediterranean region. (C) 1997 Academic Press Lim ited.