Specific Niche Characteristics Facilitate the Invasion of an Alien Fish Invader in Boreal Streams

Table 5

Results of logistic regression with forward selection for the occurrence of brown trout, brook trout, and bullhead in relation to environmental factors in 1994. Separate analyses were performed for 0+ and 1+ trout.

Variable	𝑏	S.E.	Wald	𝑃	Nagelkerke 𝑅^2
Brown trout 0+					0.117
Depth CV	7.402	2.987	6.141	0.013
Constant	−3.409	1.270	7.209	0.007
Brown trout 1+					0.267
Velocity CV	6.693	1.925	12.089	0.001
Constant	−3.196	1.169	7.481	0.006
Brook trout 0+					0.599
pH	−5.745	1.400	16.845	<0.001
Constant	36.195	9.095	15.836	<0.001
Brook trout 1+					0.461
pH	−4.431	1.104	16.101	<0.001
Constant	28.377	7.315	15.048	<0.001
Bullhead					0.441
pH	3.055	1.040	8.636	0.011
Canopy cover	−0.082	0.032	6.557	0.003
Constant	16.424	6.422	6.541	0.010