Impact of the N treatments on soil properties.

Soil surface (0–15 cm) properties [total N and C, C/N ratio, concentrations of Nin – extractable inorganic N, NO3− – nitrate, and NH4+ – ammonium, OM – organic matter, and pH (H2O)], in the first (May 2007) and fifth (May 2011) springs of the experiment, according to the N addition treatment (Control, 40A, 40AN and 80AN). Different letters refer to significant differences between treatments (ANOVA p<0.05 followed by a Bonferroni test), while * refers to significant differences between 2007 and 2011 (there were no significant interactions between time and treatment, p<0.05 – Table S3). Values represent the mean (n = 3 experimental plots per treatment) ±SE.