Table S5 Summary of observed gross primary productivity at FLUXNET sites divided into low (k d<0.35) and high (k d>0.65) k dregimes for different bins of absorbed shortwave radiation at the surface (K abs). Differences in gross primary productivity between the regimes that are statistically significant (p<0.01) are in bold and cases where not enough data are available to perform (a) two-tailed t-test are in grey.