Table 2 Variation partitioning by partial canonical correspondence analysis (CCA) of fish distribution explained by three groups of environmental variables, geographical (Geo: altitude, latitude, longitude), hydromorphologic (Hydr: depth, surface) and eutrophication (Eutr: alkalinity, conductivity, total phosphorus, chlorophyll a)
Run | Responder | Environmental variables | Covariable | Total inertia | % Variation | |
|---|---|---|---|---|---|---|
Total effect: all environmental variables | ||||||
Species | All groups | – | 1.397 | 81.0 | ||
Partial effect 1 | Combination: Eutr and Geo and Hydro | |||||
1 | Species | Eutr | Geo and Hydro | 0.425 | 1.397 | 24.64 |
2 | Species | Geo and Hydro | – | 0.972 | 56.36 | |
3 | Species | Geo and Hydro | Eutr | 0.647 | 1.397 | 37.51 |
4 | Species | Eutr | – | 0.750 | 43.49 | |
Joint effect: Eutr ↔ Geo and Hydro = 0.972–0.647 = 0.750–0.425 = 0.325 | 18.84 | |||||
Partial effect 2 | Combination: Geo and Eutr and Hydro | |||||
1 | Species | Geo | Eutr and Hydro | 0.434 | 1.396 | 25.18 |
2 | Species | Eutr and Hydro | – | 0.962 | 55.82 | |
3 | Species | Eutr and Hydro | Geo | 0.622 | 1.397 | 36.06 |
4 | Species | Geo | – | 0.775 | 44.94 | |
Joint effect: Geo ↔ Eutr and Hydro = 0.962–0.622 = 0.775–0.434 = 0.340 | 19.71 | |||||
Partial effect 3 | Combination: Hydro and Geo and Eutr | |||||
1 | Species | Hydro | Geo and Eutr | 0.207 | 1.397 | 12.00 |
2 | Species | Geo and Eutr | – | 1.190 | 69.00 | |
3 | Species | Geo and Eutr | Hydro | 1.159 | 1.397 | 67.20 |
4 | Species | Hydro | – | 0.238 | 13.80 | |
Joint effect: Hydro ↔ Geo and Eutr = 1.190–1.159 = 0.238–0.207 = 0.031 | 1.80 | |||||