Key points are not available for this paper at this time.
B. G. Drake, P. W. Leadley, W. J. Arp, D. Nassiry, P. S. Curtis, An Open Top Chamber for Field Studies of Elevated Atmospheric CO2 Concentration on Saltmarsh Vegetation, Functional Ecology, Vol. 3, No. 3 (1989), pp. 363-371
Drake et al. (1989) studied this question.