Table 4.

Results of canonical correspondence analysis (CCA) and conditional effects in forward selection of environmental variables determining the species assemblage of alien and indigenous species: amphipods, isopods, bivalves, and gastropods. Environmental variables were as follows: O₂, PO₄, Cl, NO₃, NH₄, the mean temperature of the warmest quarter of the year (T_max), the mean temperature of the coldest quarter of the year (T_min), and the distance to the next navigable waterway (Distance). The significance of environmental variables was tested using a forward selection and 999 Monte Carlo permutations under full model conditions. The eigenvalues of the first two canonical axis (CA) and explained variance (%) by the CAs and the order of the environmental variables including λa, P, and F are given. Significant variables are given in bold

Amphipods				Isopods				Bivalves				Gastropods
CA	1	2		CA	1	2		CA	1	2		CA	1	2
Eigenvalues	0.13	0.05		Eigenvalues	0.07	0.01		Eigenvalues	0.19	0.13		Eigenvalues	0.22	0.08
Variance	5.2	7		Variance	4.6	5.5		Variance	3.2	5.5		Variance	3.1	4.2

Variable	λa	P	F	Variable	λa	P	F	Variable	λa	P	F	Variable	λa	P	F
Cl	0.06	0.001	20.8	Cl	0.03	0.005	8.7	Tmin	0.1	0.001	9.1	O2	0.16	0.001	15.2
Tmax	0.05	0.001	13.5	Tmin	0.02	0.002	6.3	Tmax	0.09	0.001	5.0	Cl	0.09	0.001	8.4
Tmin	0.04	0.001	13.8	Distance	0.01	0.04	3.4	Cl	0.07	0.001	4.5	Distance	0.08	0.001	7.8
Distance	0.03	0.001	9.7	NO3	0.01	0.03	3.7	Distance	0.08	0.001	4.5	NO3	0.03	0.002	2.8
PO4	0.02	0.003	8.5	Tmax	0.01	0.14	2.0	NO3	0.07	0.001	4.6	PO4	0.02	0.03	2.4
NO3	0.01	0.001	3.9	O2	0	0.49	0.6	PO4	0.04	0.03	2.3	Tmin	0.03	0.001	2.5
NH4	0.01	0.02	3.5	NH4	0	0.72	0.3	O2	0.03	0.04	1.9	Tmax	0.02	0.01	2.0
O2	0.01	0.11	1.9	PO4	0	0.91	0.1	NH4	0.01	0.81	0.6	NH4	0.01	0.12	1.5