Measurement of CO₂ exchange in lichens: a new method

Results from studies of carbon dioxide assimilation in lichens cannot be tested independently against growth studies. To compensate for this, rapid, more rigorously controlled experimental systems must be used to sample a much wider range of environmental conditions.Methods in popular use are found to be inadequate in these respects.A new simple system is described which permits the response of net photosynthesis in lichens to be examined more efficiently than was previously possible.