Environmental conditions	Environmental conditions	Environmental conditions	Environmental conditions	Environmental conditions	Environmental conditions
Parameter	N	Average	Median	Minimum	Maximum	SD
Lake Ditkevi water temperature (°C)	1881	11.9	11.9	7.8	15.9	1.5
Rainfall (mm/day)	1948	6.1	1.6	0.0	189.5	11.2
Air temperature (°C)	1825	11.0	9.6	2.0	25.8	3.6
Relative humidity (%)	1825	77	83	19	99	17
	δ18O (‰)	δ18O (‰)	δ18O (‰)	δ18O (‰)	δ18O (‰)	δ18O (‰)
Type of sample	N	Average	Median	Minimum	Maximum	SD
Precipitation	512	-10.60	-10.36	-22.40	-2.24	4.22
Lake Chirripó	48	-9.84	-9.78	-16.90	-5.64	1.56
Lake Ditkevi	66	-9.06	-9.21	-13.13	-5.77	1.67
Lake Morrenas	38	-9.06	-9.65	-12.33	-1.88	2.31
Stream water	74	-11.15	-11.19	-14.56	-5.00	1.55
	δ2H (‰)	δ2H (‰)	δ2H (‰)	δ2H (‰)	δ2H (‰)	δ2H (‰)
Type of sample	N	Average	Median	Minimum	Maximum	SD
Precipitation	512	-73.98	-71.56	-165.05	-4.68	34.10
Lake Chirripó	48	-71.78	-70.34	-118.49	-46.08	10.39
Lake Ditkevi	66	-64.89	-66.11	-94.34	-41.90	11.22
Lake Morrenas	38	-66.23	-69.49	-86.43	-26.14	14.76
Stream water	74	-78.08	-78.34	-101.71	-38.10	10.15
	d-excess (‰)	d-excess (‰)	d-excess (‰)	d-excess (‰)	d-excess (‰)	d-excess (‰)
Type of sample	N	Average	Median	Minimum	Maximum	SD
Precipitation	512	10.79	11.12	-10.87	27.94	5.48
Lake Chirripó	48	6.91	5.99	-0.97	16.71	3.77
Lake Ditkevi	66	7.57	8.04	-0.36	16.33	3.70
Lake Morrenas	38	6.28	7.62	-11.08	15.55	5.84
Stream water	74	11.17	11.00	-8.20	20.04	4.97