Fig. 1

a General location of the study area. b The Vallés lowland is a highly anthropogenised mosaic-like landscape with disseminated forest patches. c, d Historical (1956) and recent (2009) view of a sampled forest patch. e Oaks of the five different age classes sampled (see Section 2) are represented by coloured points. Class 1, yellow; class 2, light green; class 3, dark green; class 4, orange and class 5, red