Unstandardized regression slopes (b) and standardized slopes (β) are each reported with 95% confidence intervals (shown in parentheses) as well as sample sizes (n) and coefficients of determination (r2). Covariates shown in bold text have slopes (95% confidence intervals) that exclude zero and are therefore considered statistically significant.
| Hypothesized effect | Covariate | n | b | β | r2 |
| Temperature | Mean annual air temperature | 128 | 1.32 (−0.11 to 2.75) | 0.16 (−0.01 to 0.34) | 0.02 |
| Mean annual water temperature | 107 | 1.32 (0.74 to 1.90) | 0.39 (0.22 to 0.57) | 0.15 | |
| Canopy shading | % Forest cover in catchment | 128 | −0.56 (−1.06 to −0.06) | −0.19 (−0.37 to −0.02) | 0.03 |
| Stream size | Basin area | 128 | 0.10 (0.02 to 0.19) | 0.21 (0.03 to 0.38) | 0.03 |
| Mean annual discharge | 102 | 0.04 (−0.03 to 0.11) | 0.10 (−0.08 to 0.27) | <0.01 | |
| Hydrology | Flashiness | 124 | −0.23 (−0.64 to 0.19) | −0.10 (−0.27 to 0.08) | <0.01 |
| CV discharge | 124 | −0.20 (−0.86 to 0.45) | −0.06 (−0.24 to 0.13) | 0.01 | |
| Minimum 30-day consecutive flow | 124 | 1.36 (0.39 to 2.33) | 0.24 (0.07 to 0.42) | 0.05 | |
| Channel substrate | Average sediment size (unweighted) | 88 | −0.10 (−0.22 to 0.02) | −0.17 (−0.38 to 0.04) | 0.02 |
| Average sediment size (weighted) | 88 | −0.12 (−0.24 to 0.00) | −0.20 (−0.41 to 0.01) | 0.03 | |
| Land cover | Impervious surface in basin | 124 | 3.24 (−0.19 to 6.67) | 0.16 (−0.01 to 0.34) | 0.02 |
| % Medium density urbanization in catchment | 128 | 3.39 (1.11 to 5.68) | 0.25 (0.08 to 0.42) | 0.06 | |
| % Crop cover in catchment | 128 | 0.86 (−0.46 to 2.18) | 0.11 (−0.06 to 0.29) | 0.01 |