. 2016 Jun 7;7:799. doi: 10.3389/fpls.2016.00799

Table 4.

Tree-ring carbon isotope characteristics (Δ¹³C, Δ¹⁸O, BAI, C_i, C_i/C_a, and iWUE) in P. cembra, P. abies, and L. decidua during the period 1975–2010.

	P. cembra		P. abies		L. decidua
	Change	Average (±SE)	Change	Average (±SE)	Change	Average (±SE)
Δ¹³C [‰]	*1.9*^a	17.2 ± 0.7^a	*1.8*^a	17.3 ± 0.6^a	1.1^b	18.8 ± 0.484^b
Δ¹⁸O [‰]	*-2.2*^a	35.9 ± 0.9^a	*-2.7*^a	35.0 ± 1.052^b	*-2.0*^a	35.6 ± 0.883^c
BAI [cm²]	*5.3*^a	7.6 ± 3.8^a	7.9^b	5.7 ± 2.473^b	*9.8*^b	5.8 ± 3.3^b
C_i [μmol mol^-1]	*65.2*^a	203.5 ± 19.6^a	*63.06*^a	208.5 ± 19^a	*56.2*^a	228.8 ± 16.9^b
C_i/C_a	*0.1*^a	0.6 ± 0.03^a	*0.1*^a	0.6 ± 0.03^b	*0.00*^b	0.6 ± 0.03^c
iWUE [μmol mol^-1]	-3.1^a	81.0 ± 2.9^a	-2.2^a	78.4 ± 2.6^b	-1.6^a	67.8 ± 2.2^c

Significant changes from 1975–2010 at P < 0.05 are in bold and italics. Between species differerences in change and average (±SE) are marked with different letters. Change values were calculated as the slope of the corresponding least-squares linear regressions (Table 2) multiplied by the number of years of the study period 1975–2010 (=36).