Table 1. Envfit results and range of the environmental and hydrological variables included in the analysis shown in Figure 3.

	NMDS1	NMDS2	R2	P-value	Range
Temp (°C)	−0.99881	−0.0488	0.401	0.001	6.24 to 32.3
WRT (days)	−0.99124	−0.13205	0.4185	0.001	0.01 to 10 523
geographic km2	−0.99853	−0.05429	0.3162	0.001	0.002 to 12 753
CA (km2)	−0.99484	−0.10143	0.2177	0.001	16 to 55 148
d-excess	0.92625	−0.3769	0.1889	0.001	−5.44 to 37
pH	−0.29484	−0.95555	0.6178	0.001	3.3 to 8.95
cDOM	0.31115	0.95036	0.2318	0.001	0.01 to 58.8
DIC	0.29063	−0.95684	0.2285	0.001	0.282 to 42.2
%C2	0.48359	0.8753	0.2873	0.001	0.13 to 0.48
%C5	−0.32545	−0.94556	0.2047	0.001	0.05 to 0.25

Abbreviations: CA, catchment area; cDOM, colored dissolved organic matter; %C2, percentage of fluorescent component C2 (humic-like DOM); %C5, percentage of fluorescent component C5 (freshly produced labile DOM); DIC, dissolved inorganic carbon; T, water temperature; WRT, water residence time.

The degree of fit within the whole ordination space (R²) and for each ordination axis (NMDS1, NMDS2) are shown.