Vegetation structure
In order to assess the effects of livestock on vegetation structure we performed two Principal Component Analyses (PCA). Both PCAs were based on standardized correlation matrix with the function PCA (package ‘FactoMineR’ (Lê et al., 2008)). The first PCA was performed using the data from all study trees (N = 72) to assess the differences among the three categories of trees (control, one-year exclusion and ten-years exclusion). In the second PCA, we only included control oaks (N = 24) to analyse the differences among the three oak savannas with free-range livestock excluding the effect of the experimental treatment. PCA tables can be found in Table S7.