As with all sectors of our society, the agricultural and rural fabric of Aosta Valley has undergone profound changes. Most of the arable land has been abandoned, having given way to permanent meadows which is used for foraging cattle. The number of farms have been greatly reduced, but the regional load of cattle has not decreased at the same level because the average size of farms has grown. Managing larger companies means facing increasingly complex organization and, in the presence of a fragmented and dispersed estates, this makes it impossible to aPDOt the same agricultural practices on all parcels being cultivated. The variety in the fertilization and the frequency of mowing or grazing, together with differences in altitude, exposure and inclination help to explain the heterogeneity of the vegetation of meadows and pastures in the Aosta Valley.
They find themselves, in the Aosta Valley, in a dozen different type of permanent grassland, which differ in the botanical composition and hence, the productive potential, presenting a change in the quality of the grass during the growing season. These different fields are one of the central elements of biological and environmental richness of the region and, with their different flowers, participate in presenting a variegated mosaic of colours on the slopes and on the valley floor.
From studies of the Aosta Valley almost 150 different species of meadow plants were identified, of which 31 were grasses and 15 were legumes (Roumet et al., 1999). Among the grasses the most common are oat, the orchard grass, bluegrass and different fescues, including legumes such as red and white clover, birdsfoot trefoil, sainfoin and alfalfa. There are many colours belonging to dicotyledonous flowers: the white of the wild chervil, pink of the hogweed and daisy, from blue of the sage to yellow of Common Buttercup, salsify and dandelion.
Assortment of different vegetations in the meadows, is matched by an even greater wealth of plant life in the mountain pastures, where they found no less than twenty types of vegetation, covering a very wide range of potential forage (Bassett and Bornand, 2001 ).
They identified about 500 species of plants, some of which are more abundant and characterise particular plant communities.
The orchard grass dominates at lower altitudes, in well-fertilized pastures while red fescue and bentgrass are abundant in the pastures of medium fertility and the Matterhorn is mostly present in grasslands with acidic and impoverished soils. Pork rind is present on the warmest and sunniest grassy slopes which are are also characterised by sesleria and brachipodio, sheep's fescue and rock rose. Higher up, in the alpine meadows, dominating the scenery are the curved sedge and scented alpine clover.