In aquatic GPP measurement, which bottle only shows respiration?
In the light-and-dark bottle method, a dark bottle blocks photosynthetically active radiation while retaining plankton and microbes from the water sample. Without light, photosynthetic oxygen production stops, but cellular respiration continues and consumes dissolved oxygen. The decline in oxygen during incubation estimates community respiration. A transparent light bottle permits both photosynthesis and respiration, so its oxygen change estimates net community production. Combining the two changes gives an estimate of gross primary production: oxygen produced overall equals the net increase i
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17