Table 2.

Pearson’s correlation coefficients and significance levels for relationships between ε _met and climate parameters within the period from 1983 to 1995 (n = 13).

	VPD	PRE	PDSI	TMP	SD	RAD	C a	SPEI 1	3	4	6	8	12	16	24	36	48
Year	0.26	−0.69	−0.51	−0.17	−0.12	−0.34	−0.73	−0.18	−0.20	−0.24	−0.28	−0.28	−0.10	0.03	0.03	−0.04	0.04
Spring	0.52	−0.71	−0.29	0.23	−0.08	−0.19	–	−0.28	−0.01	0.02	−0.08	−0.13	0.20	0.27	0.10	0.07	0.22
Growing season	0.27	−0.67	−0.52	−0.14	0.01	−0.33	–	−0.27	−0.17	−0.20	−0.29	−0.29	−0.18	0.03	0.02	−0.04	0.03
Summer	0.17	−0.67	−0.54	−0.47	−0.30	−0.51	–	−0.39	−0.44	−0.46	−0.31	−0.35	−0.29	−0.05	−0.03	−0.10	0.05

ε _met denotes the average deuterium fractionation by metabolic processes at glucose H¹ and H² (±SE = 3.4‰, n ≥ 3). Data for the calculation of ε _met were acquired for tree‐ring glucose of Pinus nigra laid down from 1983 to 1995 at a site in the Vienna Basin. Climate parameters: VPD, air vapour pressure deficit; PRE, precipitation; PDSI, the self‐calibrating Palmer drought severity index (Wells et al., ²⁰⁰⁴); TMP, air temperature; SD, sunshine duration; RAD, global radiation; C _a, atmospheric CO₂ concentrations; SPEI, the standardised precipitation–evapotranspiration index calculated for different timescales (1–48 months) (Vicente‐Serrano et al., ²⁰¹⁰). Integration periods for the calculation of climate parameters: January to December, year; March to May, spring; March to November, growing season (Wieloch et al., ²⁰¹⁸); and June to July, summer. Significance levels: < 0.05, light blue; < 0.01, blue.