Abstract
A method is presented for the control of carbon dioxide concentrations within the roots of Fraxinus pennsylvanica Marsh. The results indicated a linear fit of the root CO2 concentrations to the CO2 levels of the treatment gases: y= l.l. x+105 (r= 0.98, 18 d.f.). The method presented for controlling CO2 can be easily modified for other gas mixtures and plant species.