2.4. Data Analysis
Factorial ANOVA tested the effects of the two substrates and two organic
amendments on soil properties, number, height and slenderness index, and
plant cover. The assumption of homogeneity of variance was tested using
Levene’s test and differences between individual means were evaluated by
Tukey’s post hoc test at p < 0.05. Regression analyses were
performed to test for relationships among variables. SPSS v.20 (SPSS,
Inc.) was used.
The whole pool of inventoried species was analyzed looking for a pattern
of species distribution through the plots by means of Detrended
Correspondence Analysis (DCA). In the DCA it was assumed that plots
closer to each other in the ordering diagram had a greater floristic
similarity. The analyses were carried out using PAST software (Hammer et
al., 2009).