Figure 2

Biplots from principal component (PC) analysis, showing the interrelations, orientations, and groupings of the environmental driver dimensionless numbers with the response dimensionless number \(\left( {\frac{{NEE_{CO2,uptake} }}{PAR}} \right)\). NEECO2,uptake, PAR, ST, SS, Pa, and cp refer, respectively, to daytime net uptake fluxes of CO2, photosynthetically active radiation, soil temperature, porewater salinity, atmospheric pressure, and specific heat of wet soil.