Table 6: Results of logistic regression with forward selection for the occurrence of brown trout, brook trout, and bullhead in relation to environmental factors in 2004. Separate analyses were performed for 0+ and 1+ fish.

Variable S.E. Wald Nagelkerke Brown trout 0+ 0.082 Macrophytes −0.029 0.014 4.283 0.039 Constant 0.576 0.720 0.640 0.424 Brown trout 1+ 0.136 Particle size 0.556 0.226 6.043 0.014 Constant −0.774 0.926 0.699 0.403 Brook trout 0+ 0.219 pH −1.802 0.676 7.100 0.008 Velocity 3.260 1.586 4.223 0.040 Constant 9.193 4.570 4.047 0.044 Brook trout 1+ 0.189 pH −2.137 0.723 8.733 0.003 Constant 13.688 4.838 8.006 0.005 Bullhead 0.383 pH 2.994 1.092 7.513 0.006 Depth 0.136 0.062 4.772 0.029 Constant −21.717 8.127 7.140 0.008