Table 6.

Regression model to explain the change in Ellenberg N score

Variable	Compartment	Regression coefficient	Significance	TMV%
Latitude	Climate	−0.055	**	7.8
Fagus	Tree	−0.263	*	4.2
Mediterr. oak	Tree	−0.633	**	6.0
NO3 (1995)	Deposition	6.03E‐04	**	8.6
Undetermined				−14.5
Total expl. var.				12.1

The model is derived by stepwise exclusion of terms from a full model containing all variables included in Appendix S8, until only terms with a significant (p < .05) effect remain. TMV = top marginal variance, that is, the drop in explained variance when omitting this term from the model. Significance levels as in Table 2. The negative “unexplained” variance is due to interaction effects, and further explanation see text (N = 99).