Photosynthesis, respiration and net primary production of sunflower stands in ambient and elevated atmospheric CO2 concentrations: an invariant NPP:GPP ratio?

Cheng, W., Sims, D. A., Luo, Y., Coleman, J. S., Johnson, D. W. (2000). Photosynthesis, respiration and net primary production of sunflower stands in ambient and elevated atmospheric CO2 concentrations: an invariant NPP:GPP ratio?, Global Change Biology, 6 (8), 931-941, 10.1046/j.1365-2486.2000.00367.x