Gas Transport in the Marsh Grass,Spartina alterniflora

Spartina plants have continuous gas spaces from the leaves to the tips of the roots. Oxygen values in the roots are as low as 3 per cent and increase toward the stem. Carbon dioxide values are highest in the rhizome and decrease up the stem and toward the root tips. Oxygen and carbon dioxide moved through the plants at equal rates for equal gradients, and these rates agree with measurements made on plants in the marsh. Calculated oxygen and carbon dioxide fluxes for the observed gradients in the observed gas spaces agreed with measured fluxes. We conclude that gases move in and out of Spartina roots by diffusion through uninterrupted gas spaces within the plant.