Caratteri strutturali in giovani impianti planiziali a prevalenza di farnia e carpino bianco nel veneto

The Asparago tenuifolii-Quercetum roborisMarincek 1994 is the forest climax association of Po Valley. Nowadays these forests, located on a few patches in Veneto, that totally cover about 60 hectares, show serious problems in stands structure and functions. They are very important for the nature conservation even if they are fragmented in small stands. Foresters manage them as an open museum, adopting particular forestry technique to preserve and maintain the overstorey vegetation, even through new plantations near the ancient woods. Since 1988, thanks to the CAP’s strategy of set-aside, hundreds hectares of agricultural land were converted to forest in order to restore the ancient plain forest. These new forests have a lot of problems caused by errors in the projecting phase and by cultural lacks so they need a model for the management of the stands. The relationships between age and the most important tree variables, natural regeneration and herbs vegetation, were studied by a chronosequence approach over 10 forest sites. This article presents the results of the study about the diameter at breast height (henceforth: dbh) and the other tree variables relationships analyzed both at species and social class level. The authors suggested a new planting scheme aimed at promoting the natural restoration.