DINAMICHE EVOLUTIVE DI POST SELVICOLTURA IN ABETINE DELL'APPENNINO CENTRO SETTENTRIONALE

The present study aims to highlight the successional pattern of forest stands showing a simplified structure and in which the silvicultural practices have been neglected along, so far allowing an undisturbed evolution of the forest. In order to understand the management style better performing with the future increase of the structural complexity of the stands, surveys were carried out in test sites where records on the stand dynamics of the last thirty years are available. The plots are located in the Apennine silver fir stands of Vallombrosa (Tuscany) and Sasso Fratino (Emilia Romagna). The changes in structure are synthetically expressed by means of indexes of structural and floristic diversity. As for management aspects, according to the results of the present research, is emphasised that the canopy reduction is the prerequisite for a silviculture style aiming to enhance the system diversity. Gradual openings of the canopy, as the ones following selection or shelterwood systems, basing on long regeneration time span, are suitable to enahance the re-naturalisation (e.g. increasing the amount of broadleaves in the understorey) of silver fir stands. Because the undisturbed conifer stands dynamics following the abandonment of forestry practice results very often uncertain as trend and direction, it appears important to follow up the process by mean of close-to-nature silviculture interventions. In this sense, the paper finally outlines the necessity to face the interactions between forest regeneration and wild ungulate populations, which currently represents one of the most dramatic problems of sustainable management.