Fig. 2

Oxygen consumption of alum-treated model birch samples and references, as described in Table 1, shown as: a concentration of oxygen as a  % saturation in the atmosphere of the airtight bags (values shown for one sample of each set of three samples); b initial oxygen consumption rates as μg O₂ (g wood)⁻¹ day⁻¹ for all three samples in each set, calculated from data between 100 and 80% saturation (with means and standard deviations for each set given below)