observations on natural regeneration in grazed holm oak stands in the ogliastra province (sardinia, italy)

This paper deals with the effects of grazing pressure in two Holm oak (Quercus ilex) stands in Ogliastra (central-eastern Sardinia, Italy), with particular reference to the interactions with the natural regeneration processes. There is a positive interaction (facilitation) between shrubs and seedlings of tree species, as observed in other similar studies carried out by the same authors in other areas of Sardinia. Rubus ulmifolius proved to be the most efficient shrub for the protection and growth of saplings; the other shrub species play a less marked facilitating role. Although the density of shrubs hosting Holm oak seedlings is fairly high, their age and small size confirm that the current grazing pressure is incompatible with any chance of growth of the saplings and success of the natural regeneration. The conservation of these stands must therefore rely on the rationalisation of human activities through the exploitation of a whole range of resources.