Responses of photosynthesis and stomatal conductance to atmospheric humidity in some mediterranean Abies species

Abstract

Significant differences in the gas- exchange response to deltaw were found in a comparative study on 4 Abies species originating from different high elevation regions of the Mediterranean area. A. cephalonica, and A. marocana had the highest A values for a given deltaw. These 2 species had also the lowest E/4 and 818A ratios and, furthermore, 818A was constant with deltaw, which indicates optimization between C02 assimilation and transpirational water losses. These results are in good agreement with the growth performances of the studied species in southern France.