Fig. 1: CUE derived from eddy covariance observations.
From: Global variation in vegetation carbon use efficiency inferred from eddy covariance observations
a, CUE of different PFTs, which include EBF, ENF, DBF, MF, SH, SAV, GRA, WET and CRO. CUEEC represents the CUE derived from eddy covariance observations; CUEIN represents the CUE derived from inventory data. The letters over each bar indicate whether the groups are significantly different (P < 0.01; one-way ANOVA). The number under each bar means the number of samples. In the boxplot, the centre line represents the median, the circle within the box indicates the mean, the limits of the box indicate the 25th and 75th percentiles and the whiskers represent the 10th and 90th percentiles. b, Comparison of CUEEC and CUEIN at nine sites: Harvard Forest (US-Ha1, DBF), Morgan Monroe State Forest (US-MMS, DBF), University of Michigan Biological Station (US-UMB, DBF), Willow Creek (US-WCr, DBF), Turkey Point TP02 (CA-TP1, ENF), Turkey Point TP89 (CA-TP2, ENF), Turkey Point TP74 (CA-TP3, ENF), Turkey Point TP39 (CA-TP4, ENF) and Hyytiälä (FI-Hyy, ENF); the dark dots indicate the seven sites where CUEEC agrees with CUEIN, the light dots indicate the two sites where CUEEC is different from CUEIN. The r and P values indicate the correlation between CUEEC and CUEIN excluding the two outlier sites, while the value in brackets indicate the correlation between CUEEC and CUEIN including the two outlier sites. The error bars represent 1 s.d. of the CUEEC and CUEIN for each site. c, The paired basal area increment (pBAI) of DBF and ENF (Methods). pBAI is the ratio of the BAI of deciduous trees and evergreen trees at the same locations. The shaded area indicates 1 s.d. of the pBAI values under each stand age. The pBAI is indicative of the relative advantage of DBF to ENF in terms of carbon use for stem growth.
