Factors Affecting the Presence and the Diversity of Bryophytes in the Petrifying Sources Habitat (7220) in Wallonia and the Brussels-Capital Region, Belgium

Table 3

Results of the AIC stepwise model selection for species richness showing the best significant variables selected based on their weight using the complete dataset (columns on the left) or the data without 2 possible outliers (columns on the right).

Variable	Weight of the variable		Averaged coefficient		Unconditional standard error
	Full model	Model without possible outliers	Full model	Model without possible outliers	Full model	Model without possible outliers
Cover	0.992	0.992	−0.007	−0.006	0.002	0.002
PO4	0.960	0.983	−7.510	−8.361	2.572	2.479
NH4	0.709	0.300	−5.615	−1.689	4.140	2.414
Mg	0.650	0.548	0.009	0.007	0.006	0.005
pH_mean	0.587	0.616	−0.186	−0.200	0.128	0.131
Zonecont	0.309	0.300	0.065	0.058	0.086	0.080
Ca	0.300	0.269	0.001	0.000	0.001	0.001
NO3	0.274	0.276	0.004	0.004	0.006	0.006
NO2	0.230	0.229	−0.002	−0.001	0.014	0.013
Slope moderate	0.087	0.090	0.007	0.008	0.018	0.019
Slope steep	0.087	0.09	0.005	0.008	0.021	0.023