Table 2. Multiyear mean annual water use efficiency (WUE) and the standard deviation (SD) at the 32 sites for different plant functional types (PFT).

PFT	Site	Mean WUE (g C kg−1 H2O)	SD (g C kg−1 H2O)	PFT	Site	Mean WUE (g C kg−1 H2O)	SD (g C kg−1 H2O)
Broad-leaved evergreen forest	CN-DHS	2.26	0.201	Broad-leaved deciduous forest	US-MMS	1.625	0.196
	US-KS2	2.345	0.161		IT-Col	2.222	0.034
	IT-Cpz	3.126	0.175		US-Ha1	2.329	0.232
Needleleaf Evergreen forest	US-SP1	1.304	0.390		FR-Hes	3.348	0.062
	US-Fmf	2.044	0.235		DE-Hai	3.504	0.136
	ES-ES1	2.672	0.048		DK-Sor	2.937	0.236
	FR-LBr	2.865	0.222	Mixed forest	CN-CBS	1.820	0.146
	US-Ho1	3.474	0.351		US-Syv	2.183	0.183
	DE-Tha	4.050	0.276		BE-Bra	2.704	0.217
	SE-Kno	3.777	0.143	Crop	ES-ES2	1.051	0.097
	SE-Fla	1.924	0.284		FR-Avi	1.759	0.209
	FI-Sod	1.095	0.057		IT-Cas	1.681	0.180
Grassland	PT-Mi2	1.807	0.120		CH-Oe2	2.023	0.278
	ES-VDA	1.242	0.136		DE-Geb	2.361	0.115
	CH-Oe1	2.775	0.163		DK-Ris	1.773	0.383
	NL-Cal	3.523	0.253
	DK-Lva	2.369	0.450

The names of flux sites are abbreviations from the FLUXNET community.