Table 1.

The average position of taxonomic groups along the first four PCA axes.

Taxonomic group	Axis 1	Axis 2	Axis 3	Axis 4
Annelida	0.38	− 0.94	− 0.91	− 0.20
Gastropoda	0.78	− 0.10	− 0.67	0.44
Bivalvia	0.28	− 1.14	− 0.32	1.01
Crustacea	0.29	− 0.79	− 0.25	0.56
Ephemeroptera	0.89	0.24	0.38	0.23
Plecoptera	0.51	− 0.21	0.50	0.50
Odonata	0.07	− 0.81	1.33	− 0.34
Heteroptera	− 0.30	0.21	− 0.58	− 0.89
Coleoptera	− 1.20	0.15	− 0.01	0.20
Trichoptera	0.69	0.80	0.25	− 0.03
Diptera	0.50	0.51	0.11	− 0.46
Other (including several groups)	0.58	− 0.64	− 0.44	− 0.46

Minimum and maximum values are highlighted in bold.