Table 4. Mean foliar N and C isotopic values.

Site	Elevation	Mean δ15N per site	SD	Mean δ13C per site	SD
TLT01	4480	2.1	0.65	−24.6	0.79
TLT02	4370	2.7	2.90	−24.7	0.58
TLT03	4270	3.2	0.42	−25.5	2.12
TLT04	4174	1.1	1.88	−24.2	1.24
TLT05	4072	1.4	3.00	−24.4	1.10
TLT06	3970	3.5	2.91	−20.9	4.67
TLT07	3870	3.9	3.12	−20.4	4.21
TLT08	3870	5.4	2.66	−19.2	4.59
TLT09	3770	5.3	0	−26.4	0
TLT10	3670	6.0	1.40	−18.5	5.42
TLT12	3470	5.2	2.15	−17.6	4.76
TLT13	3370	7.4	1.77	−14.0	1.97
TLT14	3270	7.2	0.82	−16.2	5.50
TLT15	3170	6.1	1.27	−19.0	6.63
TLT16	3070	5.5	1.57	−13.7	2.05
TLT17	2970	4.3	1.33	−13.9	2.25
TLT18	2870	6.0	0.55	−19.5	6.64
TLT19	2770	7.2	0	−12.5	0
TLT20	2670	4.1	0.47	−18.5	7.85

SD: Standard deviation Data were obtained from 66 different foliar samples (See details in Supplementary Table 2).