TY - JOUR VL - 2 EP - 194 Y1 - 1981/// UR - https://eprints.nwisrl.ars.usda.gov/id/eprint/378/ AV - public N2 - A new theory and experimental method was developed to measure the diffusion resistance to CO? in the gas phase of mesophyll leaf tissue. Excised leaves were placed in a chamber and their net evaporation and CO? assimilation rates measured at two different ambient pressures. These data were used to calculate CO? gas phase diffusion resistances. A variety of field grown leaves were tested and the effects of various experimental errors considered. Increasing the gas phase diffusion resistance decreased transpiration more than it decreased CO? assimilation. It was concluded that gas phase diffusion resistance associated with CO? assimilation may sometimes be 100 or 200 s?m-¹ greater than the resistance implied by transpiration rates. This may be due to longer path lengths for the CO? diffusion, constricted in places by the shape and arrangement of mesophyll cells. A1 - Cary, John W. ID - nwisrl378 TI - Calculation of CO2 gas phase diffusion in leaves and its relation to stomatal resistance SP - 185 JF - Photosynthesis Research ER -