Fig. 2. Design of the growth chamber for collecting ¹⁴CO₂ and volatile organic compounds. Each glass chamber (260 x 40 x 330 mm) contained one microcosm. The chambers were connected to wash bottles of glass containing 2 M NaOH to trap CO₂ and an activated carbon trap. Air was withdrawn from the growth chamber and pumped through the traps at 700 mL h^–1.