THE FOREST VEGETATION FROM THE GARDA LAKE (NORTH ITALY)

A study about the forest vegetation occurring along the shores of the Garda lake is presented. The investigation emphasized a noteworthy veg etation diversity, related both to the habitat heterogeneity and to th e still present traces of several climatic changes that affected the a rea beginning from the Quaternary period. The examinated woodlands are the result of a compenetration between evergreen characteristic speci es of the Quercetea ilicis class, representing relicts of the climacic vegetation during the peak of the post-glacial anathermic phase, and deciduous mesothermophilous elements belonging to the Querco-Fagetea c lass order, which better reflect the present macroclimate. On the basi s of historical, chorological and ecological factors, 10 associations have been individuated, belonging to 5 alliances: Quercion ilicis, Eri co-Querciop ilicis, Tilio platyphylli-Acerion pseudoplatani, Ostryo-Ca rpinion orientalis and Alno-Ulmion. Apart from the floristic-physiogno mic point of view, the associations result well characterized also by their different edaphic, microclimatic and topographic exigences; Quer cetea ilicis stands are most often linked to well-drained hardly-slopi ng sites, where there is little competition due to more mesic species and where the human impact is lower.