Abstract: | The influence of environmental variables which are known tochange with altitude on the 13C of leaves of Nardus stricta,have been investigated in controlled environment experiments.Low temperature and an increased incidence of freezing temperaturescaused 13C to increase. In contrast, lowered atmospheric pressurereduced 13C. Increased leaf surface wetness and soil water contentalso caused a decrease. Plants from different altitudes didnot differ consistently or significantly in their responses. Key words: Carbon isotope discrimination, altitude, temperature, atmospheric pressure, freezing |